Posts Tagged ‘Design’

Performance of Combined Power System With Design of Energy Storage Controller System

Sunday, August 8th, 2010

Abstract -We investigated a small isolated fusion power system that used two types of power generation; wind turbine and diesel generation. The interaction of diesel generation, the wind turbine, and the local load is complicated because both the load and the wind turbine fluctuate during the day. These fluctuations make imbalances in power distribution (energy sources are not copy to energy sinks) that can affect the frequency and the voltage in the power system. The addition of energy storage will help weigh the distribution of power in the power network. For this paper, we studied the interaction among fusion power system components and the relative size of the components. We also show how the contribution of wind energy affects the entire power system and distribution and the role of energy storage under the transient conditions caused by load changes and wind turbine startups.

Index Terms – wind turbine, diesel generator, fusion power system, renewable energy, energy storage.

 

I. INTRODUCTION

Windmills were used to pump water and mill grain, along with many other uses [1, 2, 3, 4].

Today, wind turbines are used for similar purposes (i.e., water or oil pumping, battery charging, and utility generation). One vital aspect of wind turbine applications, especially in an industrial environment, is that wind turbines generate electricity without making pollution. Wind turbines are also well suited for generating electricity in isolated places with no relations to the utility grid [2,3,4]. But, in isolated applications, especially very small applications, the power system components (sources and loads) are limited, and the system networks are weak in many cases. Thus, any changes in the power input or output of one component may affect the rest of the system more dramatically than in a larger system where the smoothing effect of many components benefits the overall system. In this paper, we analyze a fusion power system consisting of a wind turbine, a diesel generator, a local load, and energy storage. We also present the impression of energy storage on the power system performance. The results and conclusions of this analysis apply to similar fusion power systems.

 

 

 

II. SYSTEM CONFIGURATION

The system has two types of generation: the diesel generator and the wind turbine generator (Figure 1). The

energy storage can act as a load or as a generator depending on the need. The diesel generator provides smooth output power, whereas the output power of a wind turbine depends on the wind velocity. As the wind velocity varies, so does is the power generation. For example, if the wind speed changes very smoothly, the output power of the wind turbine will also exchange very smoothly. On the other hand, wind turbulence causes the output power to fluctuate. Figure 1 is a single line diagram that represents the analyzed power system. The wind turbine has an induction generator with a capacity ranging from 40 kW to 225 kW. At low wind speeds, the generator operates at 900 rpm with a rated capacity of 40 kW. At high wind speeds, the generator speed is 1,200 rpm with a rated capacity of 225 kW. We used 150 kW of energy storage as a buffer to operate as a load or a source depending on the need. This paper discusses only fixed-speed wind turbine generation and does not cover variable-speed wind turbine generation [5]. The diesel engine, which has a rated capacity of 400 kW, is operated in parallel with the wind turbine to supply the load. The local loads are frequently residential and light loads. Other loads include water pumps, compressors, and gray equipment. An 80-kW water pump represents the transient condition of a gray load.

 

Fig 1. One line diagram of power system

 

 

III. COMPONENTS OF POWER SYSTEM

The system we discuss in this paper consists of four major subsystems: a diesel generator, a wind turbine generator, gray (industrial) loads, and energy storage. In the power system network, the weigh of committed power and immediate power must be maintained. The diesel-genset, then, must be able to keep the power balanced when the wind turbine or local load varies. This task is simple to accomplish provided the diesel genset is sufficiently sized. Even if they are vital, we will not cover the details of the dynamic model for electric machines used in the simulation. Many excellent textbooks are available on this subject.

A. Diesel Generator

In terms of an electrical system, a diesel generator can be represented as a prime mover and a generator. Ideally, the prime mover is capable of supplying any power demand up to rated power at constant frequency, and the synchronous generator connected to it must be able to keep the voltage constant at any load condition. Figure 2 is a block diagram of the diesel generator. The diesel engine keeps the frequency constant by maintaining the rotor speed constant via its governor. The synchronous generator must control its output voltage by controlling the excitation current. Thus, as a unit, the diesel generating system must be able to control its frequency and its output voltage. The inertia of the diesel genset, the sensitivity of the governor, and the power capability of the diesel engine all affect the diesel generator’s ability to respond to frequency changes. The ability of the synchronous generator to control its voltage is affected by the field winding time constant, the availability of the direct current (DC) power to supply the field winding, and the response of the voltage control regulation mechanism.

 

Figure 2. Diesel generator control block diagram

 

 

B. Wind Turbine

The main components of a wind turbine are the rotor of the turbine, which is the prime mover, and an induction generator. In general, the rotor is connected to the generator via a gearbox that matches the rotational speed. The simplest system uses a fixed-speed turbine. A fixed-speed turbine must rely on the blade-stall condition to limit the output power when the winds are at high speed. Note that, even if the rotor speed of an induction generator varies with wind speed, the speed range is within a 1% to 2% slip. On the other hand, the wind speed variation may range from 5 m/s to 25 m/s; thus, in terms of the wind turbine, the induction generator operates at a relatively “fixed speed” compared to the range of wind speed variation.

C. Induction Machines

Most electric machines used in industry as prime movers are induction motors. Two applications of induction machines in the power system network fall within the scope of this study: one as the generator on a wind turbine and the other as a motor driving large pumps and compressors. By its nature, an induction apparatus is an inductive load. This apparatus absorbs immediate power either as a motor or generator. The immediate power absorbed by the induction apparatus comes from the line to which it is connected. In a fusion power system, the immediate power comes from the synchronous generator of the diesel genset. In a wind turbine generator, a fixed capacitor is usually installed to supply some of the immediate power that the induction generator needs. Figure 3 shows the equivalent path of an induction apparatus connected to a power system. The power system is represented by infinite bus Es and the line impedance is represented by reactance Xs.

 

Figure 3. Equivalent path of an induction apparatus connected to power system

D. Various Loads

In the power system considered, there are two major loads. The first is a large water pump representing a typical industrial load. The second is a collection of loads for which the size and power factor can be programmed right through the day to represent a typical village load. The voltage at the terminal of the load varies as a result of a voltage drop across the line impedance. The voltage drop across the line impedance varies depending on the size of the current and the power factor of the load. The terminal voltage for a wind turbine generator (VS), as the output current of induction apparatus, varies from start-up to generating mode. During start-up, voltage drops significantly at the terminal voltage of the induction apparatus. The voltage drop across line impedance is caused by the current surge during start-up. In addition, the phase angle of the stator current is very large and lagging. The combination of a poor power factor and a lagging, large current surge makes a voltage dip at the terminal of the induction apparatus during start-up. Thus, a start-up of fleeting duration is preferable to a prolonged one

E. Energy Storage

The energy storage can be of different types (i.e. flywheel, battery, hydrogen/fuel-cell, hydropower etc.). In this paper, we assumed energy storage with a power converter interface to the power network. The power converter is connected to the energy storage at one end. With variability of wind resource, energy storage is an brilliant contributor to the power system. The energy storage behaves like a large buffer to accommodate the unequal on the spot energy in the power system. Ideally, at any instant of time, there should be a zero net exchange between the energy sources and the energy sinks (both real and immediate power). If this weigh is not achieved, the voltage and frequency of the system changes to maintain equilibrium. At any instant, the energy storage behaves either as an energy source or energy sink depending of the mode of surgical procedure.

Figure 4. Energy Storage control block diagram

 

It is assumed that the energy storage has a power converter interfacing the power network. Even if it is possible for the power converter to function as a immediate power compensator, the cost of a power converter is very expensive compared to other means of immediate power compensation currently available in the market. Keep in mind that the size of the power semiconductor in the power converter is limited by its current limit and its voltage limit. Thus, minimizing the current quick through the power switches will lessen the current rating of the power converter and will lower the cost. For this paper, we only used the power converter to process real power in and out of the energy storage. Figure 4 shows a block diagram of energy storage control algorithm. It uses frequency deviation to indicate a real power imbalance in the system. The frequency deviation is also used as the pointer to control the energy storage output. If the load power demand is higher than the power supply available, the frequency of the diesel generator will at a snail’s pace drop. Other energy stored in the system includes the kinetic energy in the turbine blades, the diesel generator inertia, and energy in the inductors and capacitors, etc.

 

F. Weigh of Energy in the System

In the isolated system we studied, the weigh of real and immediate power must permanently be maintained. The weigh of real power is maintained by the governor of the diesel generator. The weigh of immediate power is maintained by the exciter of the diesel’s synchronous generator. When the load demands more power than the diesel and the wind turbine can produce, and the diesel engine has reached its highest limit, as the loads take up again to increase, the governor of the diesel cannot push more power, and the rotor speed of the diesel will start to drop. The frequency of the generator will then drop until weigh is reached or the system collapses. The voltage in the system is also an indicator of the weigh in the system. When the immediate power demand from the loads is higher than what can be provided by the diesel generator, the capacitor, and other means of compensation, the system voltage will drop. Even if the size of output and input of the energy storage is adjustable, it is limited by its ratings. For this paper, we assumed that the energy storage is capable of storing and providing long-term energy to the power network to maintain system weigh. In reality, only a limited amount of energy can be stored. We will not discuss energy analysis in detail in this paper. In practice, the energy will be stored when the wind turbine produces enough power and the diesel is operating under light load. The actual loads are divided into critical and non-critical loads. Critical loads are supplied at all times and non-critical loads are served only if there is enough source and it will be shed off the system when the voltage or frequency drops not more than the allowable limit. With the existence of sufficiently sized energy storage, it is possible to serve all the loads (critical and non-critical) all the time.

IV. DYNAMIC ANALYSIS

The case studies look at different aspects of major power system components in the power network. The first case study investigates the diesel power component. In the power network, a diesel generator must maintain system weigh by responding properly to power changes.

A. Case Study I: Diesel–Wind Turbine Interaction

A diesel generator consists of a diesel engine and a synchronous generator. The diesel engine is responsible for controlling the frequency and keeping it constant through its governor. The synchronous generator is responsible for controlling the voltage via its field winding and voltage controller. Undersized diesel engine: The ability of a diesel engine to exchange speed is its accelerating or decelerating power. The diesel accelerates when the input power is higher than the electrical output power of the generator (including losses).

The diesel decelerates when the input power is lower than the electrical output power of the generator (including losses). An oversized diesel engine does not have problems accelerating or decelerating, but an undersized diesel engine may make problems, during, for example, the start-up of a wind turbine or large compressor. Figure 5 illustrates a condition where the diesel is undersized with respect to the load. The genset frequency and the terminal voltage of the wind turbine generator are shown on the top graph, and the real power of the diesel, wind turbine, water pump, and local load are shown on the bottom graph. At start-up, the wind turbine uses the smaller, 40-kW generator to motor up and bring the induction apparatus up to speed. Because the wind speed is low, the wind turbine operates at low output power, and the local load is set to 200 kW. The diesel engine has a rated power of 400 kW. At t = 2 s, the wind turbine is turned on. As we can see, the voltage dip and the frequency dip are not very large, because the wind turbine is started using a smaller generator

 

Figure 5. Voltage, frequency, and power to illustrate

an undersized diesel genset

At t = 10 s, the 80-kW water pump is started up. The startup time for the water pump is longer than that of the wind turbine because the wind turbine is started when the rotor speed is close to the synchronous speed and the wind turbine also gets some help from the wind. The voltage drop is not very significant, but the frequency of the diesel drops about 3%. The diesel output power increases to cover the real power needed, whereas the contribution from the wind turbine is insignificant because the wind is low. For a fleeting time, the induction generator enters the motoring range between t = 10.8 s and t = 11.3 s. After the condition is restored, at t = 14 s, the bonus local load (300 kW noncritical) is turned on, bringing the total load to 580 kW. Because the diesel can carry only up to 400 kW and the wind’s contribution is very small at about 40 kW, the voltage and frequency start decreasing, and the voltage and frequency sensors notice the exchange. If the frequency drops not more than 95% and the voltage drops not more than 90% for an elapsed time of 0.5 s, the controller will drop the bonus load (300 kW) and keep the critical load (200 kW) to regain the voltage and frequency. After the load is shed at t = 14.5 s, the frequency and voltage ultimately return to habitual. When the frequency drops, the wind turbine’s power contribution suddenly jumps because of a sudden increase of generating slip. Ultimately, the genset frequency increases again for a fleeting period and the induction generator enters into the motoring condition (between t = 14.5 s and t = 15 s). This condition worsens if the mechanical time constant of the wind turbine rotor (including the blade) is higher than the diesel genset time constant. In other words, the varying of the genset rotor speed is much quicker than the varying of the wind turbine rotor speed. The response to the load exchange is shown by how quick the governor corrects the frequency and how quick the generator’s field excitation control reacts to the voltage changes. Undersized diesel engine with energy storage: As shown in the previous subsection, an undersized diesel engine cannot supply all energy needed, and it must shed some of the non-critical load to retain power-system stability. To remedy this situation, a 150-kW energy storage is installed to bring the combined output of the diesel genset and energy storage up to 550 kW. Figure 6 shows the improved power system after the energy storage is added. The same simulation is performed apart from it is now equipped with an energy storage. There is a significant improvement in the frequency regulation after the storage is installed to stabilize the system. The non-critical load (300 kW) survives even during low wind conditions. The frequency dips during the wind turbine start-up and the water pump start-up, and when the 300 kW load non-critical load is switched, it is reduced dramatically. Obviously, the capability of the energy storage to deliver a large amount of power instantaneously plays a major role in restoring the frequency of the power system. An bonus benefit is noticed in the system voltage behavior of the wind turbine. Because the exchange in the frequency deviation presented to the wind turbine induction generator is small and smooth, the behavior of the stator current at the induction generator is also smooth. Thus it reduces the Ldi/dt and overall voltage drop across the line.

Oversized wind turbine:

When the wind power output exceeds the power required by the load, the synchronous generator of the diesel genset becomes a synchronous motor that tends to accelerate the rotor speed of the diesel engine. The excess energy from the wind power, then, tries to drive the diesel engine. Because the diesel engine has only a small braking capability ensuing from engine compression, the frequency control can be lost when the extra power generated by the wind turbine is sufficiently high.

 

Figure 6. Voltage, frequency, and power to illustrate

an undersized diesel genset with storage

In Figure 7, the diesel generator has a rated power of 400 kW, the local load is initially set to 280 kW and at t = 4 s, and the local load is set to 100 kW. When the diesel is started, there is only a local load of 280 kW. The wind turbine is then started at t = 2 s with a 225-kW induction apparatus. Even if the diesel genset is rated at only 400 kW and the wind turbine is started with a 225-kW induction apparatus, the effect of wind turbine start-up on the power system is very mild, frequently because the induction apparatus current is limited by a soft start. A soft start is a device that limits early current during start-up. It consists of a pair of back-to-back thyristors installed in series with each phase of the motor winding. Because the firing angle of the thyristor can be controlled, the size of the early current can be adjusted by controlling the firing angle of the thyristors. As we can see (Figure 5), the same wind turbine (225 kW) draws a early power of 300 kW, but after the soft start is installed (Figure 7), the power surge during start-up drops to about 100 kW. After the wind turbine enters generating mode (at about t = 2.5 s), the local load (280 kW) is mutual between the diesel genset (55 kW) and the wind turbine (225 kW). The voltage and frequency are maintained constant, and the diesel genset

 

 

 

Figure 7. Voltage, rotor speed, and power of an

oversize wind turbine

generates only a small percentage of its rated load (about 13%). This makes a significant contribution to fuel savings from the wind energy. At t = 4 s, the local load is reduced from 280 kW to 100 kW; the wind speed stays the same. As a result, the wind turbine tries to supply 225 kW, but the only load available is 100 kW. As a result, the synchronous generator of the diesel genset turns into a motor (negative power), the governor loses its speed control, and frequency run off is triggered. This is an example of the wind turbine being oversized compared to the local load. In such a case, a dump load (water heater, water pump, battery charger, etc.) is usually deployed to keep the diesel genset generating, which prevents it from motoring. Minimum power generation of the diesel genset is usually pre-set (for example, 15%–40% of the rated load). If the generated power of the diesel genset is less than the preset value, the dump load should be deployed. The dump load must be sized so that the diesel genset will permanently generate power above its minimum set point. The dump loads are normally non-critical loads used to store excess electrical energy in a further form, such as heat (water or space heater), electric charge (battery charging), or potential energy (water pump). Oversized wind turbine with energy storage: As shown in the previous subsection, an oversized wind turbine can drive the system into an unstable condition because of the incapacity of the diesel engine to keep the frequency constant. An energy storage installed in the power system network is not only useful to remedy the undersized diesel engine but also for cases where there is an excess power produced by the wind turbine. Without energy storage, the wind turbine can drive the synchronous apparatus into motoring region and the frequency output will be out of control. With a power converter to interface between the energy storage and the power network, the energy storage is capable of quickly absorbing excess power generated by the wind turbine and hold the generator rotor speed from a run off condition. As shown in Figure 8, the frequency run off can be prevented by using energy storage to capture the excess power in the power network.

Figure 8. Voltage, rotor speed, and power of an

oversize wind turbine with energy storage

B. Case Study II: Charging the Storage Under Habitual Condition

The energy storage will be charged only when there is an energy surplus from the wind and the required network load is very light. Because the governor of the diesel generator will permanently maintain the frequency constant, the output power of the diesel generator is an indicator of the power within the system available to charge the energy storage. One benefit of charging the energy storage during this condition is that the efficiency of the diesel engine is at its peak when it is operated near its rated power. Thus, when a surplus of power is detected within the system, the energy storage will be charged and some energy will be stored within the system. The amount of energy and the size of charging power depend on the size of the surplus power. The charging process will be stopped when the energy storage reaches its limit. Maximum charging current is also limited by the energy storage and by the power converter interface. Figures 9 shows the charging process. Initially there is enough wind speed to start the wind turbine. The diesel generator is supplying a constant load of 280 kW (power factor = 0.995 lagging) all the time. As the wind turbine generates full power (225kW), the diesel governor redistributes the load and there is a load sharing between the wind turbine and the diesel generator. As the transient settles out, it is shown that the diesel generator is contributing a very small amount of power to the load, thus the charging mechanism is started. The energy storage is charged at a snail’s pace until it reaches its limit.

 

 

Figure 9. Real power flow in the power system

 

In Figure 9, the charging of energy storage during habitual condition is limited to 75 kW, which is about 50% of the rated power of the capacitor. This limit ensures that the power converter still has enough headroom to deliver or absorb power during an emergency. For example, if there is some loss of the loads in the power systems, the energy storage must absorb the loads loss to avoid a sudden exchange in frequency. Similarly, to compensate for a sudden load increase to the power systems (e.g. the water pump is started), the energy storage must release energy to the power system to keep constant frequency at the diesel generator. As shown in Figure 9, the real power used by the energy storage to stabilize the frequency takes precedence over the charging power used to charge the storage. This can be seen especially when the water pump is started at about t = 15 seconds.

V. CONCLUSION

After presenting an overview of the components of the power system under investigation, we described the operating characteristics of the components as they relate to voltage and frequency variations in the power network. The analysis shows the dynamic interaction among the wind turbine, diesel engine, large loads, and energy storage. It also demonstrates the dynamics of real power weigh and how the system is stabilized with the controlled energy storage. The voltage regulation is very minimal and the frequency regulation is controlled very closely. The voltage regulation is controlled frequently by the weigh of immediate power in the system and the time constant of the excitation system of the generator. The frequency regulation depends on the energy storage control, the size of the energy storage, the total inertia in the system (temporary energy storage).Many technical solutions can be implemented to remedy the shortcomings covered in this paper. But, as in any power generation system, the fiscal implications of the solutions must be carefully considered.

REFERENCES

[1] E. Muljadi, L. Flowers, J. Green, and M. Bergey. 1996. “Electrical Design of Wind-Electric Water Pumping.” ASME Journal of Solar Energy Engineering 118:246–252.

[2] J.T.G. Pierik and M. De Bonte. 1985. Quasi Steady State Simulation of Autonomous Wind Diesel Systems (Status Report). Report No. ECN-85-091. Petten, The Netherlands: The Netherlands Energy Research Foundation.

[3] A.J. Tsitsovits and L.L. Freris. 1983. Dynamics of an Isolated Power System Supplied from Diesel and Wind. Proc.IEEE 130, Part A, No. 9:587–595.

[4] J.T. Bialasiewicz, E. Muljadi, G. Nix, and S. Drouilhet. 1998. “RPM-SIM Simulator: A Comparison of Simulated versus Recorded Data. “Proceedings of WINDPOWER ’98.” Bakersfield, California, 423–432.

[5] E. Muljadi and C.P. Butterfield. 2001. “Pitch-Controlled Variable-Speed Wind Turbine Generation,” Transactions of the IEEE-Industry Applications Society.

 

 

Cpa Website Design & Development

Sunday, August 1st, 2010

 

If you’re looking for a custom designed CPA and accounting website, here are some things you should consider. Done right, your website will be an effectual marketing tool, improving your company’s bottom line. These pointers will improve your site, turning visitors into clients and providing valuable air force to your existing clients.

1. Your website is for professionals – while its content shouldn’t be dry, it also shouldn’t be too flowery. It should speak to your target audience (those requiring accounting air force), and it should clarify why your air force are best for them.

2. Respect your visitor’s time by making the information they need simple to find – in addition to being attractive, your site should be user-friendly and simple to navigate. Make sure that the team you hire has competent designers, as well as a skilled technical department.

3. Your website should be more than an online business card. Spot yourself as an authority with compelling content and tools – tax calculators, FAQs, and financial guides demonstrate that you have the practical knowledge to help your clients achieve their financial goals.

4. Enhance the value of your website with tools for your clients – for example, a file transfer system that allows them to easily and securely exchange sensitive files with your firm. In addition to saving you time by making transfer of large files simpler, a secure system like this will build your client’s trust in you by demonstrating that you value their privacy.

5. A monthly newsletter is an simple way to build loyalty and stay in touch with your client base. Many website designers include automatic monthly newsletters – take advantage of this feature to keep clients up-to-date on the newest tax laws and information.

6. Make yourself accessible to your clients – contact information should be prominently showed on your site. Ensure that the contact info you post is up to date, and provide simple ways for clients to question for appointments and information with contact forms on your website.

Following the rules above will result in pleased and satisfied clients and an ever-growing client base.

 

Dallas Web Design Team Discuss Differences Between SEO And SEM

Friday, June 18th, 2010

Marketing your website can be the most complicated part of running a business online. You want your business to be successful, but it can be hard to know where to start. Both SEO and SEM can be vital in helping your website succeed. But, do you need one or the other or both. Do you even know the difference? Where can you turn for answers as to what your website needs to succeed? Texas Web Designers can help you find the answers to these questions and more. They are the experts in both SEO and SEM.
Making cash with your own online business has become much more complicated over the years. The formulas that major search engines like Google and Yahoo! use for determining your search engine ranking are permanently varying. It can be reasonably confusing to figure out how to use the right keywords and the right keyword density and that is just one aspect of the equation. Texas Web Designers have the knowledge and the experience to give your website exactly what it needs to succeed by way of SEO or SEM.
SEO stands for Search Engine Optimization. This is the art and science of making your website rank high in search engine rankings so that people who are looking for your type of business see your website more evenly in their search results and you get more visitors to your website. There are a number of other ways to optimize your site for search engines and Texas Web Designers are experts in giving websites the best SEO possible.
On the other hand, SEM stands for Search Engine Marketing. Search engine marketing takes advantage of other methods of driving traffic to your website instead of search engines. SEM includes article marketing, press releases, forum posts and blogging and blog comment posting. Every article, comment or blog will contain a link to your site. Viewers can find relevant content about a topic they are interested in that relates to your harvest or air force and then be able to click straight to your website. Texas Web Designers are experts in producing the kind of SEM that gets people to take notice of your website and generates interest in your harvest.
The keywords used in your SEM content will attract a targeted audience to your website and make greater credibility for your site with search engines. So even though SEM is different than SEO it still helps to optimize your website for search engines in a roundabout way. Texas Web Designers do a excellent job of publicizing your website with SEM on the internet and generating interest in your company and harvest.
SEO and SEM are different but both will help you get more viewers to your website and place more cash in your bank account. Internet marketing techniques are continually varying and it is increasingly hard to keep up with the most current SEM techniques means more business for your website. Hiring Texas Web Designers can give you a leg up on the competition and remove the guesswork from your internet marketing plot.

Swro Design and Energy Recovery Part 2: Hydropro Design

Monday, June 14th, 2010

Design RequirementsTraditionally Hydropro has permanently place the needs of the customer into the forefront of its company philosophy. By doing this, Hydropro has permanently stayed abreast of the newest advancements in technology in the water treatment field. In this case, frequently because of the remote place (nearly everything, including fuel for the diesel generators, is delivered by ship), the most vital customer needs were associated with conserving energy and maintaining reliability. Availability of replacement parts was also a major concern due to the remote place and the lead-time required to ship bits and pieces to the island. A further concern Hydropro had to address was ease of surgical procedure and ease of maintenance, as the remote island of Ebye did not have any skilled RO plant operators. The end result would incorporate all these requirements to produce a reliable supply of filtered water from a seawater source for the citizens of Ebye. In the original RFP, KAJUR requested twin 75,000 gpd SWRO units (supple to 100,000 gpd) designed for a seawater feed of 45,000 mg/l TDS. The proposal presented by Hydropro was for two Seawater Reverse Osmosis Water Treatment units each designed to produce 75,000 gallons per day. Permeate water was projected to be of less than 300 mg/l TDS based on feed water from seawater wells with a maximum TDS of 50,000 mg/l and an SDI of less than 3. Each unit was designed to be easily supple to a daily capacity of 100,000 gallons by the addition of one pressure vessel containing seven seawater membranes. All instrumentation, piping, valves, headers and pumps were pre-sized to accommodate the expansion. Each proposed SWRO system consisted of four pressure vessels containing seven membrane elements each arranged in a single, one-pass array. With the expansion, the system would consist of five pressure vessels in a single staged array. Each system was designed to operate at a 30-40% recovery rate, with a maximum trans-membrane (feed to product) pressure of 1100 psi at a feed water TDS of 50,000 mg/l. With a feed water TDS of 46,000 mg/l, the trans-membrane pressure was projected to be approximately 900 psi at startup and 950 psi after three years of surgical procedure. System Design The final, installed 100,000 gpd Hydropro design consisted of the following major components and unit operations for each SWRO unit: • Sand and Particulate Filters: Two HYDROPRO Tubular filter units Model STF5M2-400- PVC/150 each consisting of one PVC housing with a 150-micron wedge wire PVC screen for the removal of sand and particles, with automatic purge valves • Micron Filters: Three gray-duty filter housings constructed of FRP/PVC and built to ASME Code X, the housings are Eden Model 24EFC each accommodating six (6) 40″ long five micron polypropylene cartridges • RO High Pressure Booster Pumps: Two high pressure feed booster pumps Grundfos Model BM 17-27R (installed in series) – horizontal centrifugal, multi-stage construction of 904L Super Austenitic Stainless Steel, each driven by a 35 HP submersible type motor rated at 460V/60Hz/3Ø utilizing a Soft start motor starter and VFD RO Low Pressure Booster Pump: One booster pump Grundfos Model BM 30-4R – horizontal centrifugal, multi-stage type of 904L Super Austenitic Stainless Steel, driven by a 7.5 HP submersible type motor rated at 460V/60Hz/3Ø controlled by a variable frequency drive • Membrane Modules: One FRP construction structural frame, five pressure vessels of FRP construction rated at 1200 psi operating pressure, 35 Thin Film Composite membrane elements ¬ 8″ x 40″, 2205 DUPLEX SS headers for feed and concentrate and Sch. 80 PVC for the permeate headers and low pressure feed, suction and concentrate piping, Allen- Bradley PLC SLC 5/04 based control system – installed in a NEMA 4X enclosure with system switches lights etc. installed on the panel door • Chemical Feed Systems: One anti-scalant dosing system and one chlorine dosing system • Freshwater Flush/Membrane Cleaning System The system skid was designed and fabricated for a compact trace due to limited installation space and to allow for shipping both units in a single container. The entire system was pre-assembled as much as possible to lessen field air force.

Swro Design and Energy Recovery Part 3: Major Component Selection

Wednesday, June 9th, 2010

The sand screens and micron filters were selected because of the durable and deterioration resistant fiberglass and PVC construction. The specific model of Eden micron filters was chosen to maintain the filter element flux at approximately 3.3 gpm/per 10″ equivalent.

Due to the relative inaccessibility of the installation site, multistage-centrifugal, high-pressure pumps have been selected for their reliability, availability of parts, economics of surgical procedure and simple maintenance. Centrifugal pumps in general are smoother, quieter, and require less ancillary equipment (i.e. pulsation dampeners) than positive displacement pumps. Hydropro has found that positive displacement pumps are much more prone to failure and lengthily downtimes than high-feature centrifugal pumps.

The Grundfos Booster Modules were chosen for several reasons. The inline style helped conserve space and provided ease of installation, allowing everything to be mounted on the same skid (with the exception of cleaning/flush tanks, raw water booster pumps, and chemical feeds). These submersible, multi-stage centrifugal pumps were also chosen because they are very well-organized and silent, and are constructed of deterioration resistant, 904L super austenitic stainless steel.

The high pressure feed and concentrate headers were made of 2205 duplex stainless steel for superior deterioration resistance, and the structural skid was constructed of FRP for low weight and zero maintenance. ERI´s Pressure Exchanger was chosen because of its high energy efficiency, fidelity, and deterioration resistant materials.

PerformanceValues for the projected power consumption rates that were presented in the proposal were based on a 27ºC feed stream of 45,000 mg/l TDS and a permeate flow rate of 100,000 gpd. The membrane manufactures projection software was used to determine the system parameters at a recovery of 35%, and these parameters were subsequently used to determine the projected power consumption. The result was an anticipated feed pressure of 900 psi and a specific power consumption rate of 3.02 kWh/m³.

Once the system was installed and operating, the specific power consumption was calculated based on actual system parameters and the result was a much lower value of 2.65 kWh/m³. There were several reasons the actual value was lower, the main reason but, was the conservative design. Because of some uncertainty in the feed water feature, the SWRO system was designed with a relatively low flux (approximately 8 gpm/ft2), and a somewhat large hydraulic envelope. As it turned out, the feed water TDS was closer to 36,000 ppm and honestly stable. The lower feed TDS enabled the system to operate at a lower membrane feed pressure of 790 psi and a higher permeate flow rate of 120,000 gpd, consequently using less energy than originally projected and making higher feature permeate.

ConclusionWith most of the system assembled, the installation was honestly straightforward and went smoothly. The two units were installed, started up, tested and operator training was completed in less than three weeks. There was, but, a problem with the feed water feature and the pretreatment system, which was exposed after only 24 hours of surgical procedure. It immediately became apparent that the raw water was loaded with particulate that was quickly fouling the sand screens and the micron filters. Fortunately, the feed system could be modified to flow into an existing 250,000 gallon seawater tank from the wells, and the SWRO feed was then drawn out of this tank. This settling tank solution worked reasonably well and provided a feed water with a pre-filter SDI of 1.25.

There was also one other performance issue that needed to be resolved. Initially, the permeate feature was less than what was projected, and it was not clear why. The system was extensively checked ant tested for leaks, and the possibility that seawater was somehow mixing with the permeate was ultimately eliminated. It was irrevocably single-minded that the membranes did not meet the design rejection required to produce the projected permeate TDS. Once the membranes were replaced, the system was making plenty of high feature permeate that was well not more than the maximum acceptable permeate TDS.

KAJUR and the residents of Ebye have since been enjoying low-cost, high-feature water for over a year now without any noteworthy system failures. They are so pleased, in fact, that KAJUR has recently awarded Hydropro a further SWRO job utilizing work exchanger energy recovery.

Mazda Design Chief Franz Von Holzhausen Talks on Design, Style

Thursday, February 4th, 2010

AutoblogGreen writers recently got the chance to hear the Chief of Mazda’s US design team, Franz von Holzhausen, give an insight into the style and design culture at Mazda. Though the name sounds like a European stylist, Holzhausen was born in Simsbury, Connecticut and is now based in California.

He reveals that specific models and concepts at Mazda are taken from nature with designs that are more likely flowing and organic than the blocky shapes seen in most production cars today. But in his designs, Mazda’s persistent “Zoom, Zoom” philosophy, as permanently, will take up again to play a huge role in the designs of future automobiles. More RWD and AWD models will be coming in the lineup, and there will also be a departure from its current range, plus greater highlights on interiors, too.

For the past 2 years, Franz has been the US Chief of Design for Mazda and is working out of their Irvine, CA design center, one of three design centers Mazda that has, the others being in Europe and in Japan.

An Autoblog writer describes this designer as young, informal and tall. Accordingly, he also resembles a southern California surfer. But when he speaks, according to the writer, he really speaks of design.

For the past few years, the Mazda corporate theme has been “Zoom, Zoom”. And since then, the company is delivering the motto with attractive exterior design, feature interior design, and brilliant engine performance as well as handling. And because of this, Mazda is growing in worth and in sales in the market, which is a excellent thing for a firm in the Ford family of nameplates.

Franz talked about the show cars that were recently showed at different auto shows. Like what he revealed on Mazda designs, each car he discussed was as organic rather than geometric or on steroids as some “muscular” production vehicles look today. The cars’ designs are flowing and integrated but not really ergonomic. Each car will be a front engine, rear or all wheel drive vehicle, a departure from the front wheel drive of most existing Mazda vehicles.

These designs will likely be a early point for future Mazda cars that have to comply with the new US Energy bill (with targets of 35mpg proposed for cars and trucks by 2020) when it gets passed. The industry still has to wait as to how green the cars would be.

About Mazda

Mazda’s vision is to make new value, excitement and delight to their customers through the best automotive harvest and air force. Their mission is to actively communicate with passion, pride and speed with their customers to deliver insightful automotive harvest and air force that exceed their expectations. Aside from making sure that each Mazda OEM part is feature based, the company principles integrity, customer focus, creativity, efficiency and nimble events and respects highly motivated people and team spirit. It positively spurs environmental matters, safety and society.

Php web development company and php web design services

Wednesday, February 3rd, 2010

php web development company and php web design air force

Qualified Web Development Company phpmaestro provides custom website development web application development ecommerce website design and development air force. Custom web application development air force and qualified website development at affordable rates from phpmaestro Company. www.phpmaestro.com is a php Application Development Shopping Cart for e-commerce stores. Our shopping cart software gives our client full control over your online shop its harvest design development prices shipping and payment options sales tracking marketing mailing lists etc. No programming knowledge required to install and run php cart.

Our incorporation of content management tools also helps in manage to our client’s business and organizational directories collection of data and reporting; and much more. we are in the run of making our clients pleased. The expanse of our clients includes online commerce websites corporate portals and web presence small business web sites community-based portals and many more.

Phpmaetro is

php web development company, and php web design service, php software development company E-commerce PHP Programming and asp.net Application Development company. there are several aspects of multiple pages forms that would be need to consider for the building process including quick of form principles between steps preparing form data and jumping between steps. php development qualified php programming php development company Qualified php developers Web site design development e-Commerce phpfox mods and customization. Web site design service can include: domain name hosting design and search engine submission phpfox vbulletin mods and customization.

Present day trends and rapid developments in various sectors call for the use of ‘web’ to enhance business networks. This has been favoring companies to tap the potential markets spread across countries and the vast expanse of globe. The primary criterion is “if You have a requirement and we have the solution Form principles Generally speaks and known each step of the form will generate a set of principles. These principles will be use for different things. For example at the completion of the form all principles may be saved into your database. Here I will cover each of these and suggest they can be dealt with. maybe a certain value determines which step is shown to the user next. Either way we need to footstep the principles somehow between each page.

We place forward the following web solutions

Internet related programming

Website designing

Web applications development

Application maintenance

Application reengineering

Data transfer software

Mail gateway (Internet/ Internet mail server)

E-business solutions

Web hosting solutions

web site promotion air force

myspace blog layout generator create blog myspace layouts design blog background blog design templates

Monday, January 25th, 2010

Hide Your Acquaintances List – MySpace Code

By Linda Roeder, About.com

See More About:

blogging, blogger,blogspot,make cash from blog

* myspace

* social networking

* myspace hacks

* myspace codes

blogging, blogger,blogspot,make cash from blog

Web Page Ads

Katrina Kaif Hot Pictures New Acquaintances Free Text Messages Connecting Acquaintances Hide Top Acquaintances

Hide your MySpace acquaintances list with this MySpace code. Maybe you’re tired of choosing who should be at the top of your MySpace acquaintances list. Or, maybe you just don’t want people to know who your acquaintances are.

blogging, blogger,blogspot,make cash from blog

Find out how to take your acquaintances list off your MySpace profile. You can still see your acquaintances list, but no one else will.

Difficulty: Simple

Time Required: 2 minutes

Here’s How:

1. In your About Me section penetrate:

If you liked this code, you’re also going to like:

Hide Acquaintances and Comments

and

Hide Top Acquaintances, Make “All Acquaintances” Link Instead

Suggested Reading

* 14 Reasons You Should Join a Social Network

* 22 Ways To Exchange Privacy Settings In Facebook

* Getting Started With MySpace

* Staying Safe While Online

* Make Lots of MySpace Layouts

Related Articles

Blogs are usually aimed for the organic traffic from the SEOs. Search Engines like blogs because their information is constantly updating. You can also optimize the content of your blog for the specific keywords so that your articles would get more attention of the SEOs. Don’t forget that blogs have the informative aim. So if you promote some air force there, don’t overstuff it, because the visitors will not like it. People will come to your blog to look for the information. Try to place forward your visitors as much useful information as possible, so that they want to stay your blog again and bookmark your page.Unlike the websites, blogs are more personal place in the Internet. You can personalize your blog by offering some information about yourself, count a picture of your dog. It will make your visitors be loyal to you and stay your blog more evenly. Be yourself and share your trustworthy point of view when you write for your blog. You can also write from the first person there, it will make you closer to your readers.Besides the SEO, the other way for generating more traffic to your blog is the links exchanging. You can exchange links with other blogs and as a result you will receive traffic from the other blogs as well as the other blogs will get visitors from your blog. Don’t be courteous that it may produce all your visitors go to the other blogs. Link exchanging strategy proved its effectiveness. It lets more traffic stay your blog. Even if some of them leave your page, those who are interested in your air force will stay with you.Don’t underestimate the blogging. This simple and not expensive method can play a main role in the promotion of your internet based business and help you make cash from home.

* Hacks, Widgets, Templates, Cool Material for Social Networking Profiles

* Hide Acquaintances and Comments – MySpace Code

* Athlete Focus – Social Networking for Action Athletes

* Who Are Your Facebook Top Acquaintances?

* MySpace Hacks – MySpace Hacks to Edit Your MySpace Profile

Linda Roeder

Guide since 1998

Linda Roeder

Personal Web Pages Guide

* Sign up for my Newsletter

* My Blog

* My Forum

Swro Design and Energy Recovery Part 1

Monday, January 25th, 2010

Square Design Previously, the standard Hydropro design for SWRO with energy recovery incorporated a single multistage centrifugal pump (or positive displacement) with a Hydraulic Turbo Booster. This design is honestly simple and generally does not require a significant increase in system controls or instrumentation and is for the most part a sound, and energy well-organized SWRO design. The hydraulic turbo booster converts the hydraulic energy of the concentrate stream to mechanical energy and then applies this mechanical energy to the full flow of the feed stream in the form of a considerable pressure boost. In a single stage SWRO system, the energy benefit associated with this type of energy recovery device is realized solely in the form of lower pressure (and thus lower horsepower) requirements for the high pressure feed pump. Because the equations used to predict the pressure boost produced by a HTB are usually specific to the manufacturer and dependent upon the system parameters, they will not be explicitly discussed here. In this case, a reasonable assumption would be a 300 psi (693 feet H2O) pressure boost from the HTB operating in a system as described in Example 1 not more than. The following example is used to demonstrate the reduction in high pressure feed pump horsepower requirements: This HTB energy recovery device provides a substantial reduction in specific energy consumption, which, depending on the duty cycle and cost of power could pay for itself in a relatively fleeting amount of time. New TechnologyThe concept of a work exchanger energy recovery device was certainly not new, and several variations of these devices have come and gone. But, at the time of this proposal, there seemed to be a new approach to the design of these positive displacement devices that eliminated many of the problems associated with previous versions. The PE from Energy Recovery, Inc. (ERI) is an example of a fresh work exchanger device that was in a spot to profoundly affect the design of SWRO and the energy recovery industry. The main thought of the Pressure Exchanger is its ability to frankly transfer most of the hydraulic energy in the concentrate stream to an copy amount of feed water. The result is a side feed stream copy in flow to the concentrate stream (minus bearing leakage) that is boosted to near membrane feed pressure by the Pressure Exchanger. A small high pressure booster pump is then required to boost the high pressure feed exiting the PE so that it equals the discharge pressure of the high pressure feed pump and the two feed streams can be combined. This pressure boost financial statement for pressure losses associated with inefficiencies of the pressure exchanger, losses across the membranes, and piping and fitting losses right through the system. By significantly reducing the size of the high pressure feed pump to approximate the flow of permeate, the horsepower of the high pressure pump can be reduced by approximately two thirds of the total pumping power required. This substantial reduction in horsepower is, for the most part, specific to the high pressure, low recovery nature of the SWRO system. To illustrate the effect of this reduction in pumping power required, the following example is used: Even if there are other energy considerations besides just pumping power when comparing a system with no energy recovery and a system with a PE, this simple analysis shows a significant reduction in energy consumption when using a Pressure Exchanger.

Commission Hijacker Hidden Inside Your Web Page Design!

Tuesday, January 19th, 2010

As a person nearly obsessed with Web site marketing, I am evenly at odds with my Web site designer acquaintances as to what is vital. They know that I like them and I mean no offense so all is excellent.
For all Web masters especially those who count on commissions selling other people’s harvest, some Web design flaws could really hurt. The following are some common and some not so common flaws that can rob you of commissions by masking your affiliate links from visitors without your knowledge, sending the visitors to incorrect landing pages, lowering your Web sites search engine ranking and wasting your valuable time on maintenance and tracking.
Fixing these flaws makes a clear path to more productive Web design and higher commissions.
1- Error 404 Disease.
Test your Web site for this widespread and deadly disease that keeps sending your potential customers to the never land of server error 404. Go to your Web site home page, which in our case is http://www.askdomain.com. Then add a slash and a touch after the main url. For example, “emailmarketing.html”. The complete url of this example is http://www.askdomain.com/emailmarketing.html
What will you see? Our home page, right?
Now, go to your own Web site and repeat the process. Penetrate a url from a page on your Web site that you know does not exist. Do you see a message related to error 404? If so, your Web site is losing hard earned traffic and potential customers. Contact your Internet hosting provider to help you cure this and place a customized error message on your site. A custom error 404 message displays your sales message or redirects these lost visitors to your home page.
2- Long Affiliate Links & Ad Blockers
Long affiliate links permanently make problems especially when they break up in email campaigns. But now there is a more serious threat: Ad blocking. These ad blocking scripts view your affiliate links and banners as advertising, assume the client doesn’t want to see them and block them completely from view. The dark humor in this is you’re your stats show the banners and links as showed but the visitors do not see them. What will this do to your sales and commissions?
The most standard Internet Security and Firewall software comes with default ad blocking ON! Most if not all users will never take the time to turn it off for your sake or mine.
This blessing in disguise forces us to solve several marketing issues at the same time.The solution is honestly simple and it is done in four steps.
Step one – Make an internal directory and call it a touch like merchants or resources. We use “find” in one of our Web sites.
http://www.dailyfinder.com/find/
Step two – Make a page and name it after the merchant. In this case we called it “the business end of Websites.” The complete url looks like:
http://www.dailyfinder.com/find/the-business-end-of-websites—v19605.htm
Step three – Within your page, you can place a redirect url code. So instead of showing a link to :
http://www.prowebvalue.com/?hop=optiword
You show a link to:
http://www.dailyfinder.com/find/the-business-end-of-websites—v19605.htm
Of course in this example we are using a small more sophisticated system and database driven Web site and this is why you see those weird code “v19605.”
Go ahead and test both urls, you will not see any difference in destination, but Ad blockers may block the first one but not the second one. You can lose commissions using one and get paid using the other. Significant difference, don’t you agree?
This process will also help improve keyword base internal between which we will discuss more in later articles.
3- In print Work-In-Progress
Don’t use your Web site as a filing cabinet for work-in-progress projects. Any time you place your work-in-progress page or script on your Web site, you risk having them included in search engines. Go to Google and type in:
site:www.yourwebsite.com
At risk of making it too obvious I like to mention that in the above url I mean for you to replace the term “yourwebsite” with your actual Web site.
Look at the list. Are these pages you want to have listed on the search engines? Click on a few links, do they end in error 404?
Remember that every unproductive page of your Web site may replace a productive and completed page on Google and other search engine directories. Can you see the hurt this could produce? Yes, we can permanently recover but how long will it take?
Work-in-progress does not be in the right place on your Web site. Complete your projects previous to you place them on line.
Warning – Previous to you remove any pages, make sure you have a back up and your customized error 404 is in place.
4- Missing robot.txt file.
Some directories and files are necessary for running your Web site but have no marketing value that you want to announce to the world. Robot.txt text file tells search engines to leave these files alone and do not index and show them to Web surfers.
For example, your image directory or your policies directory does not contain anything of value so you tell visiting search engines not to bother with them. An example of robot.txt file that excludes these directories is:
User-agent: *
Disallow: /images/
Disallow: /policies/
For more details refer to http://www.robotstxt.org/wc/norobots.html
Do you have a robot.txt file on your Web site?
May both Web site pages and days of your life be productive.