Energy Efficiency Of Pump Research Articles

Development of new-generation pumps for the feed system of large power units

Main results from design developments of a sequential totality of condensate, booster, and feed pumps for thermal power units of the gigawatt class are described. The presented design solutions are innovative in nature and are aimed at achieving better energy efficiency, higher reliability, and longer service life of the main-cycle pumps.

Energy efficiency in irrigation distribution networks II: Applications

Over recent years the modernisation of irrigation water distribution systems has mainly consisted of changing from open-channel gravity-based systems to pressurised piped systems. This has reduced water losses through seepage and evaporation, but has greatly increased energy consumption and energy expenditure. A methodology described in Part I to calculate global energy efficiency is here applied to a water distribution network located in south-eastern Spain. In addition, several measures are proposed to improve global energy efficiency by individually quantifying the effects of improvements to pump energy efficiency and supply energy efficiency on the final energy savings. The application of all the measures proposed increased the global energy efficiency from 22% to 32.7%, which represents an energy saving of 34.3% with respect to current energy consumption. The results show that the best pump energy efficiency does not match the conditions for minimum energy consumption, highlighting the importance of jointly considering both energy saving measures to optimise global energy efficiency. The method enables the contribution of improvements in pump energy efficiency and supply energy efficiency to the final saving of energy to be quantified individually. This will be useful for prioritising the adoption of measures to improve energy efficiency in light of the financial benefits they provide.

Prospects for advancement in the energy efficiency of oil-producing sucker rod pumps

This paper considers variants for improving the energy efficiency of oil-producing sucker rod pumps with new alternative electric drives based on valve electric motors instead of existing ones based on serial asynchronous motors. As an option, the drive of a sucker rod pump with a linear cylindrical motor valve motor is proposed.

Evaluation of Water and Energy Use in Pressurized Irrigation Networks in Southern Spain

A procedure for evaluating water and energy use in pressurized irrigation networks was developed. Performance indicators were derived from the International Program for Technology and Research in Irrigation and Drainage (IPTRID) and the Institute for Diversification and Energy Savings (IDAE) in Spain and applied to ten representative irrigation districts with on-demand pressurized networks during the 2006–2007 irrigation season. The results confirm the high energy requirements needed for operating these irrigation schemes. To apply an average depth of 2,589 m3/ha, the energy required was estimated to be 1,000 kW h/ha. Power requirements per unit of irrigated area were 1.56 kW/ha and the pumping energy (PE) efficiency was 58%.

Theoretical and mathematical models of the torque of mechanical losses in the pump used in a hydrostatic drive

The paper presents theoretical and mathematical models of the torque of mechanical losses in the pump with theoretical (constant) capacity qPt per one shaft revolution (with constant theoretical working volume VPt) and geometrical (variable) capacity qPgv per one shaft revolution (with variable volume VPgv). The models may be used in the laboratory and simulation investigations of the pump energy efficiency and the hydrostatic drive efficiency.

Energy efficiency in irrigation distribution networks I: Theory

The energy consumption of the pressure irrigation distribution systems is strongly influenced by both the proper functioning of the pumping stations and by the spatial distribution and layout of the networks. In this paper a method of calculating the global energy efficiency (GEE) of irrigation distribution systems is proposed. This includes the pumping energy efficiency, which depends on the efficiency of the pumping stations, and the supply energy efficiency, which depends on the spatial distribution and layout of the system. Two procedures are presented to obtain the GEE, one as a water head balance and power approach; the other as an energy approach. The method has been applied to a hypothetical but representative example of an irrigation distribution system. The results show that the procedure is useful for identifying the causes of efficiency loss and that it can be used as a tool for rehabilitation of an existing system, or the evaluating energy efficiency of a new design.

ANALYSING LOSSES IN HYDROSTATIC DRIVES

The paper introduces three levels of details in the analysis of losses in hydrostatic drives which are carried out at IFAS of RWTH Aachen University (Germany). The first level of detail investigates the over-all system efficiency, the second level is focused on components while in the third level of detail the tribological contact in hydrostatic displacement machines are analyzed. Due to an increased environmental awareness and rising energy cost energy efficiency becomes a crucial factor in system design, components and single tribological contacts. Therefore the efficient conversion of mechanical into hydraulic energy and vice versa is the main objective when developing e.g. mobile construction machinery. An increase in the energy efficiency of hydraulic pumps, motors, valves and cylinders directly leads to significant reduction in energy consumption of hydrostatic drive lines and working kinematics. From the system point of view the power consumption of the diesel engine, as the power source of most mobile machinery, has to be reduced in order to increase tank-to-wheel efficiency. Modern management strategies for mobile machinery have to include diesel engine, drive line and working hydraulic with focus on an efficient operation of the engine.

Center of volume and total heart volume variation in healthy subjects and patients before and after coronary bypass surgery

Total heart volume variation (THVV) and center of volume variation (COVV) likely affects the efficiency of cardiac pumping, but no study has determined COVV of the heart throughout the cardiac cycle or the effect of surgery on THVV in adults. Therefore, the purposes of this study were to determine COVV in healthy adults and patients with cardiac failure due to ischemic heart disease (IHD), identify any difference in THVV between these two groups, and determine how these parameters are affected by coronary bypass surgery. Six healthy volunteers and eight patients before and after surgery were investigated with cardiovascular magnetic resonance imaging. The atrioventricular plane movement (AVPM), THVV and time resolved three-dimensional coordinates of the center of the cardiac volume (COVV) were measured. COVV followed a loop in 3D space that between the end-points was approximately 2 mm with no difference between healthy subjects and patients before surgery (P = 0.093), although AVPM was significantly lower in patients (P = 0.002). However, after surgery the COVV during the cardiac cycle doubled (P = 0.012) and the increase in THVV was significant (P = 0.050), although of very small magnitude, and the AVPM remained unchanged (P = 0.401). COVV and THVV were similar in patients and healthy subjects even though AVPM was lower in the patient population. After surgery, however, COVV doubled despite a very small change in THVV and no change in AVPM. Taken together, the results of this study may provide new insights into the energy expenditure and efficiency of cardiac pumping.

Energy performance of air-to-water and water-to-water heat pumps in hotel applications

We present work on measurement of the energy performance of heat pumps for hotel operations in subtropical climates. Two city hotels in Hong Kong were investigated. The first case was an application of an air-to-water heat pump to provide heating for an outdoor swimming pool during the heating season. The second case was the installation of three water-to-water heat pumps to complement an existing boiler system for hot water supply. The heating energy output and corresponding electricity use were measured. The heat pump energy efficiency was evaluated in terms of the coefficient of performance (COP), defined as the heating energy output to the electrical energy use. The air-to-water heat pump provided 49.1 MW h heating while consuming 24.6 MW h electricity during the 6 1 2 -month heating season from mid-October to April. For the water-to-water heat pumps, the estimated annual heating output and the electricity use were 952 and 544 MW h, respectively. It was found that the heat pumps generally operated in a COP range of 1.5–2.4, and the payback period was about two years, which was considered financially attractive.

Economic outlook for German pump manufacturers in 2002

This issue's special focus looks at Germany, the world's second largest producer of liquid pumps. First we have an assessment from the Pumps Association of the VDMA - Germany's machinery and plant manufacturing association - of the economic situation for the country's 180 or so pump manufacturers. This is followed by a series of product updates from some of Germany's leading pump manufacturers, covering innovations for the chemical industry, and the oil and gas sector, and opportunities for improving the energy efficiency and life-cycle costs of pumps through the adoption of novel motors. We conclude with two case studies concerning the handling of waste water and food products.

Modeling selection of a heat pump integrated with a power unit

Energy efficiency, environmental characteristics and economic parameters of heat pumps are analyzed

Improved energy efficiency in absorption heat pump through process modification. Part II: Thermodynamic potential of liquid-liquid extraction of ammonia-water mixtures

Extraction-system-attached (ESA) ammonia-water absorption heat pumps were derived from the conventional system as a strategy to improve the energy efficiency of the conventional ammonia-water absorption heat pump. The ESA absorption heat pumps were obtained by attaching a liquid-liquid extraction unit in the conventional system. Theoretical thermodynamic simulation of the ESA and conventional ammonia-water absorption heat pumps showed that a higher COP and less irreversibility occur when the ammonia-water mixture is separated by the liquid extraction process instead of the non-isothermal process used in the conventional system. The ESA systems employing nitrobenzene as the extraction solvent gave the highest COP and the lowest irreversibility.

97/03235 Heat pump energy efficiency regulations

97/03235 Heat pump energy efficiency regulations

Two-Phase Velocity Distributions and Overall Performance of a Centrifugal Slurry Pump

Back-scattering LDV has been used to investigate particulate two-phase flow in a centrifugal slurry pump. The measurements reported here have been made with a dilute suspension of 0.8 mm glass beads at the impeller-casing flow interface. This interface is of practical importance because the corresponding velocity and concentration results can be used to determine the pump head and flowrate. The present study evaluates the connection between the liquid and solids velocity distribution measured around the impeller and the pump performance determined from measurements at the pump inlet and outlet. The analysis of the velocity triangles for both phases shows the effect of the pump flowrate and inlet recirculation on the pump head at the impeller outlet, as well as the effect of particle slip on pump energy efficiency. A separate group of characteristic curves is proposed to represent the periodical fluctuations of the pump flowrate, head, and loss of efficiency due to particle slip, as a function of the impeller position.

The cost-effectiveness of heat pumps in specific buildings in South Africa

Water heating heat pumps are extremely energy efficient and large savings can be realized when they are compared to direct electrical resistance heaters. In spite of the energy efficiency of heat pumps, a large number of residential buildings in South Africa still use electrical heaters to heat water. The reason for this is that heat pumps are considerably more expensive than electrical heaters. Building owners tend to choose the system with the smallest initial cost and do not compare the two systems on the basis of life-cycle cost. It is also difficult to calculate the life-cycle cost of a heat pump because it depends on many factors like climatological conditions and water temperature. In this paper a methodology is developed to calculate the life-cycle cost of a heat pump hot water installation. The model is used to investigate the effect of daily runtime, electricity tariff, hot water consumption and geographical location on the cost-effectiveness of heat pumps. The cost-effectiveness of heat pumps increases with daily run time, water consumption and electricity tariff. Heat pumps are more cost-effective near the coast than in the interior. If sized correctly, heat pumps are more cost-effective than electrical heaters for all major cities in South Africa. The cost-effectiveness of heat pumps for two specific buildings, one a university student hostel in Potchefstroom and the other a hotel in Durban, is also investigated. For both cases it was found that heat pumps are more cost-effective than direct electrical resistance heaters.

Taking account of the mutual influence of the inverse population and the luminescence density in estimating the energy efficiency of pumping of a three-level active medium in nonsteady conditions

Taking account of the mutual influence of the inverse population and the luminescence density in estimating the energy efficiency of pumping of a three-level active medium in nonsteady conditions