Design, Fabrication, and Testing of Small Wind Pump

A wind pump prototype with 3.6 m rotor diameter, 19 m hub height above ground and 0.22 mm reciprocating pump stroke has been developed at the Department of Mechanical Engineering, Mekelle University. The prototype was designed and manufactured locally. Theoretical model based on combined efficiency of the rotor and the reciprocating pump was used to estimate the performance of the wind pump. One year wind speed data collected at 10 m height was extrapolated to the wind pump hub height using wind shear coefficient. The model assumed balanced rotor power and reciprocating pump, hence did not consider the effect of pump size. The theoretical model estimated the average daily discharge to be around 50 m 3 and 30 m 3 at 8 m and 12 m head, respectively. The prototype was tested with the same pump stroke but two different size pumps at two different heads. The pumps were with internal diameter of 55 and 70 mm and the test heads were at 8 and 12 m. Measurement of the flow rate, rotational speed and wind speed were made every 10 minutes during the test period. The data collected were analyzed to find the performance of the wind pump at the two test heads and two pump sizes. The flow rate data was plotted against binned wind speed data to determine the linear fit function. The linear fit function was then used to estimate the flow rate at any wind speed. With the 55 mm pump the measured average daily discharge was 20 and 19 m 3 at 8 m and 12 m head, respectively. With the 70 mm pump the measured average daily discharge was 41 m 3 and 30 m 3 at 8 m and 12 m head, respectively. Keywords : Wind pump, Windmill, Performance testing, Pump efficiency, Pump discharge, Ethiopia.

A 6.1m rotor diameter Kijito wind pump was tested for the relationship of water discharge and wind speed in a micro-irrigation setup on Rusinga Island along the shores of Lake Victoria in Kenya. Wind speed measurements were recorded using an installed 10m-cup anemometer placed approximately two rotor diameters away from the wind pump. Discharge record measurements were made using an Arad water meter positioned immediately after the wind-pump air chamber. The objective was to establish a field relationship of the wind-pump discharge and the wind speed. The results indicate the performance of the wind-pump at site to be within the cut-in speed and mostly below the rated wind speed. The cubic model (Q = KV3) was not appropriate as the constant depended on arbitrary fitting or choice. A linear model was instead found to be a suitable relation between wind-speed and discharge for synchronous recording intervals greater than 3 hours. Journal of Civil Engineering, JKUAT (2001) Vol 6, 27-44

This study describes new considerations in the desi gn and development of Archimedean’s Pipe-Screw especially for water pumping in case of low head hi gh volume form open farm pond at Rajamangala University of Technology Rattanakosin, Thailand. The objectives of this research is to develop an Archimedean’s Pipe-Screw especially for water pumping in case of low head high volume form open farm pond used for water pumping with Thai sail windmill, at any location of low wind speed of Thailand and tests the performance of an Archimedean’s Pipe-Scre w Model (APSM). The experimental was carried out on diameter of Archimedean’s Pipe-Screw is φ5/8”, the pitch Archimedean’s Pipe-Screw (P) is 0.6 , 0.8, 1.0, 1.2, 1.4, 1.6, 1.8 and 2.0 D for angle slope of the screw with the horizontal ( α) is 20, 25, 30°C in laboratory scale Archimedean’s Pipe-Screw model. Archimedean’s Pipe-Screw tests were conducted to assess the performance of characteristics of Archimedean’s Pip e-Screw model. A model of pump has been manufactured; 1.0 m long with the blade small rubbe r tube was constructed. The output of the experimen ts recommenced for development the prototype of Archimedean’s Pipe-Screw for the Thai sail wind pump. The prototype of pump has been manufactured, 4.0 m long, 8 m diameter. This wind pump has twelve triangular sails sweeping a circle of 8 m diameter. For the construction of this Archimedean’s Pipe-Sc rew wind pump all efforts were made to use maximize materials and local parts available in the market for large scale of Archimedean’s screw-pipe for Thai sail win d pump. The cost of material and parts is 145,000 B aht excluding the cost of machining and fabrication. Wa ter discharge was in the range 0.005-0.081 lps. It can be seen maximum water discharge of pitch Archimedean’s Pipe-Screw (P) is 1.4D at 80 rpm for α = 20° was 0.081 lps. For the result of prototype of Archimede an’s Pipe-Screw for Thai sail wind pump, it was fou nd that the curves for the prototype of Thai sail wind mill coupled to twelve Archimedean’s Pipe-Screw pump of wind speed and the discharge of was increased de pending on wind speed. The discharge amount varied between 9.56-38.23 m 3 /h at head of 1.5 m in wind speeds from 1.0-5.0 m s -1 that the overall efficiency of this windmill for water pumping was highest (76.96%) at wind speed of 1.4 m s -1 .

Wind energy is one of the promising renewable energies that could provide electricity and other mechanical power. Wind energy market is dramatically growing in many European countries, but wind power is only 0.2% of the total renewable energy uses that is only about 2% of the primary energy consumption in Korea. It is widely accepted that wind resources fur power generation are only limited in some areas including coastal regions and mountainous areas in Gangwon province in Korea, particularly in terms of large scale wind power developments. In this study, wind velocity data were analyzed with respect to the potential utilization. The data provided from National Weather Service were used for the analysis. In addition, field wind data were also collected and analyzed for the comparison between the national data. The comparison showed that there were significant differences between the experimental station and the national station that are about 5km away. Annual average wind speed at the experimental station was less than 2 m/s, which is not enough fur wind power generation. It seemed that the topographic condition resulted in a significant difference in wind speed. When 600 W and 2.5 kW wind turbines were used, annual power productions were only 186 kWh and 598 kWh, respectively. When the average wind speed is lower, wind pumping is an alternative use of wind. At the experimental station, the average pumping rate of at the head of 3 m was expected at a 2.5 m rotor under the conditions that efficiencies of the rotor and the pump were 40% and 80%, respectively. It did not seem that the wind pumping was not applicable at the station either. A higher wind speed was required to install the wind machines. Meanwhile, wind pumping would be applicable in conditions with lower pumping heads. Other applications were introduced far further wind energy utilization, including wind powered ventilation and friction heat generation in greenhouses.

Chapter 496 - Wind Pumps in Sudan

هدف از انجام‏دادن ‏این پژوهش بررسی عملکرد پایگاه داده بازکاوی ECMWF برای توزیع زمانی-مکانی تندی باد در شرق ایران و روند آن است. به این منظور، از داده‏های بازکاوی ECMWF با تفکیک افقی 125/0×125/0 درجة قوسی استفاده شد؛ عملکرد داده‏ها با استفاده از 11 ایستگاه سینوپتیک با دورة آماری ۱۹۸۵-2015 و به‏کارگیری نمایة آماری RMSE، MBE، MAE، و R2 بررسی شد. نتایج نشان داد Interim برای بررسی تندی باد از عملکرد بالا و مناسبی برخوردار است. متوسط بلندمدت تندی باد در منطقة مورد مطالعه 56/3 m/s است؛ بیشینه و کمینة تندی باد به‏ترتیب در جولای و دسامبر اتفاق افتاده است. آرایش اصلی باد در شرق ایران شرقی و شمالی است؛ ارتباط بین تندی باد با ارتفاع معکوس و با طول جغرافیایی مستقیم و در سطح 05/0 معنی‏دار است. همچنین، ارتباط بین عرض جغرافیایی و تندی باد نشان داد که این ارتباط در ماه‏های سرد سال معکوس و در ماه‏های گرم سال مستقیم است. بررسی روند تندی باد با استفاده از آزمون من- کندال (M-K) نشان داد متوسط روند تندی باد در هفت ماه سال مثبت و در پنج ماه منفی است. همچنین، روند تندی باد در زمان آغاز (جون) باد 120روزه مثبت (۱۹۵/۰)و در زمان خاتمه (اکتبر) آن منفی (-۱۵۲/۰) است.

A novel positive displacement, high pressure, vertical axis wind pump (HP-VAWP) was evaluated for the application of stand-alone high-pressure reverse-osmosis desalination and drip irrigation systems. The direct interface between a vertical axis wind turbine (VAWT) and a positive displacement pump that delivers a constant liquid volume per revolution has never been studied before. Understanding the interaction between turbine and pump efficiencies, where delivery pressure is determined by back-pressure alone, is critical for efficient design. Wind tunnel experiments were conducted on a small-scale two-bladed turbine (0.4 m2 cross-sectional area) that operated on a dynamic stall principle. At these small laboratory scales, the turbine and pump peak efficiencies were relatively low (15% and 28%, respectively); nevertheless, the system produced nearly constant pressures in excess of 1.5 bar for a broad operational range. Moreover, the system exhibited a basic self-priming capability, and the turbine could easily be braked by overloading the pump. A conservative field-scale analysis of an HP-VAWP system indicated that a medium-size turbine (12.5 m2 cross-sectional area) could attain a peak efficiency of 12.9%. Realistic efficiencies greater than 20% are attainable, significantly exceeding the 4%–8% typical peak efficiency of the widely used American multibladed wind pumps. Indeed, our research indicates that an HP-VAWP system is viable and requires further development. The benefits of zero carbon emissions during operation, high relative efficiency, and easy manufacturing and maintenance render the HP-VAWP ideal for stand-alone or off-grid environments.

The unique thing about this research work is that it is the first comprehensive study out of all its kinds in Pakistan. Pakistan is an agricultural country and faces dearth of water resources availability for crops. This research work is very inevitable because it fulfils the water needs and also helps to minimize the energy deficit. This research article represents the means of wind speed data collection, design of wind-driven water pumping system and analysis of the design under different wind conditions in Pakistan. Wind speed data for province Punjab and Sindh are collected from Global Wind Atlas, Pakistan Meteorological Department and World Weather Online. First, design calculations have been made on the basis of analytical methods. Then proposed design is analysed using ANSYS Fluent Simulation models. Wind energy input, lift and drag on blades, rotor power output transmitted to the pump and water discharge from the pump have been calculated and verified from the simulation results. It has been shown that for any rotor size windmill produces maximum power output when angle between blade chord and axis of blade rotation is in the range of 23°–27°. Recommended height of windmill tower for 8–12 ft rotor diameter is 35–50 ft. Designed wind pump system can lift the ground water from 50 ft depth and discharge depends upon the size of windmill used. From the outcomes of the analysis, different designs having different power output and water pumping capacity have been proposed for different operating and wind conditions in the country.

A study on the optimal matching of centrifugal pumps and large-scale wind turbines is reported. The study includes mathematical modelling of the performance of high-capacity centrifugal pumps when matched with efficient high-speed low-solidity wind turbines. The dependence of the performance of wind pumps on the dimensionless parameter v/√( gh), termed the wind pump’s Froude number, was fully analysed. Similar to earlier reported results on wind-powered piston pumps, analysis is showing that the wind pump’s Froude number is the dominant independent dimensionless parameter that fully defines the system’s performance. Operation with continuous variable transmission was analysed and shown to optimize the wind pump’s performance, particularly at medium and low wind speeds. The optimum relation between the required gearbox transmission ratio and Froude number of a wind-powered centrifugal pump was analytically established for three different pumps. In addition to continuous variable transmission operation, the analysis helps in optimally sizing constant transmission ratio systems.

In this article, we propose an application which resides in wind pumping, in particular the possibility to eliminate the power electronics interface. This fact is based on the exploitation of the torque-speed characteristic of the centrifugal type pump. The pumping system proposed in this article is made up of a three-blade turbine, two permanent magnets synchronous machines, one of which plays the role of the generator and the other motor driving the centrifugal pump. The good choice of machines and the centrifugal pump made possible the operation of the system of pumping with elimination of the static converter.The mathematical model to eliminate the static converter is developed and presented, implemented and simulated in the Matlab/Simulink environment.The simulation results obtained are validated by comparison with other simulation results of a wind pumping system with the presence of the power electronics interface.

An experimental system for sampling trace gas fluxes through seasonal snowpack was deployed at a subalpine site near treeline at Niwot Ridge, Colorado. The sampling manifold was in place throughout the entire snow-covered season for continuous air sampling with minimal disturbance to the snowpack. A series of gases (carbon dioxide, water vapor, nitrous oxide, nitric oxide, ozone, volatile organic compounds) was determined in interstitial air withdrawn at eight heights in and above the snowpack at ~hourly intervals. In this paper, carbon dioxide data from 2007 were used for evaluation of this technique. Ancillary data recorded inlcuded snow physical properties, i.e., temperature, pressure, and density. Various vertical concentration gradients were determined from the multiple height measurements, which allowed calculation of vertical gas fluxes through the snowpack using Fick’s 1st law of diffusion. Comparison of flux results obtained from different height inlet combinations show that under most conditions fluxes derived from individual gradient intervals agree with the overall median of all data within a factor of 1.5. Winds were found to significantly influence gas concentration and gradients in the snowpack. Under the highest observed wind conditions, concentration gradients and calculated fluxes dropped to as low as 13% of non-wind conditions. Measured differential pressure amplitude exhibited a linear relationship with wind speed. This suggests that wind speed is a sound proxy for assessing advection transport in the snow. Neglecting the wind-pumping effect resulted in considerable underestimation of gas fluxes. An analysis of dependency of fluxes on wind speeds during a 3-week period in mid-winter determined that over this period actual gas fluxes were most likely 57% higher than fluxes calculated by the diffusion method, which omits the wind pumping dependency.

Wind pump was a familiar technology for Indonesian farmer especially for salt production process. The evaporative salt production was required pumping power for very low head lifting and circulating of sea water. Reciprocating pumps were the most familiar pump type for coupled directly to the crack shaft of wind mill. In other hand, centrifugal reaction pump was a simple centrifugal pump type that could operate at very low shaft speed and very low water head. This experiment study investigated the centrifugal reaction pump for very low water head lifting of 1.0, 1.5, 2.0, 2.5 and 3.0 meters head respectively. The pump diameter was 1.5 meters with 5 centimeters pipe diameter. The pump was operated at 60 rpm up to 160 rpm shaft speed. The experiment resulted that the pump cut on shaft speed was depend on the water head. Higher water head also has the higher cut on shaft speed. The lower shaft speed has higher pump efficiency compared to the higher shaft speed. At the various water head, the pump efficiency has similar values at high speed (120 rpm and up).

Effect of non-uniform inflow on the internal flow and hydrodynamic characteristics of a small modular reactor coolant pump

Shitzer and de Dear (2006) used the regression equation that accompanies our 2001 windchill model (Bluestein and Osczevski 2002) to calculate windchill equivalent temperatures (WCET) at low wind speeds. They were surprised to find that WCET was not equal to the air temperature when the air was “still,” according to their definition of calm. They also found an abrupt transition in WCET above a minimum wind speed. To circumvent these inconsistencies, they proposed a correction; however, these inconsistencies do not exist. The problem is not in our model of windchill, but in their understanding of it. Their definition of still air as “any wind speed that is equal to, or below, the assumed threshold of 1.34 m s ” (Shitzer and de Dear 2006, p. 788) is the only real inconsistency. That is not how we defined it in the 2001 model of windchill, where “still air” or “calm” means no wind at all. There is no minimum applicable wind speed for calculating WCET; it can be found for any wind, right down to dead calm (Fig. 1). Because they used a wind speed of 1.34 m s 1 (4.8 km h ) in our regression equation, the WCET they thought they were calculating for someone walking in still air was actually for a person walking into a light wind. It is therefore neither inconsistent nor surprising that they calculated a value that was colder than the air temperature. The other “inconsistency” they found, the abrupt transition in WCET values, also results from their misinterpretation of what we meant by still air. WCET actually varies smoothly with wind speed (Fig. 1). Even if Shitzer and de Dear (2006) had used the regression equation properly, it would not have worked well at very low wind speeds. The regression equation was only intended for operational use. As Fig. 1 shows, it is a good approximation to the model output at wind speeds above 3 km h 1 (0.8 m s ). Lower wind speeds are not easily measured and are never reported anyway. We regret that the regression equations were published without an explicit warning of this limitation in our early paper. We did point it out in a later, more detailed paper (Osczevski and Bluestein 2005). The full model must be used to calculate WCET in this range. At wind speeds close to zero, WCET may be slightly warmer than the air temperature. This is due to the greater radiant heat transfer in the reference still-air condition, which assumes that there is no water vapor in the air. Any factor that increases the severity of the reference condition, such as greater radiant heat transfer, increases WCET. WCET is equal to air temperature at zero wind speed if the same relative humidity, that is, 50%, is assumed for the still-air condition as for other combinations of wind and temperature. Especially when there is no wind, radiant heat loss is significant: about one-half as large as the convective heat loss caused by walking in cold, still air. The supposed problems reported by Shitzer and de Dear (2006) do not exist and do not demonstrate any need to correct the windchill calculation method or the existing charts. We could make the model more elegant by increasing the relative humidity in the still-air condition to 50%, making WCET exactly equal to air temperature at zero wind speed. However, this adjustment would have no little or no operational impact. Corresponding author address: Randall Osczevski, DRDC Toronto, P.O. Box 2000, 1133 Sheppard Ave. W., Toronto, ON, Canada M3M 3B9. E-mail: randall.osczevski@drdc-rddc.gc.ca OCTOBER 2008 N O T E S A N D C O R R E S P O N D E N C E 2737

On the wind energy resources of Sudan