Performance Characteristics Of Pump Research Articles

Effect of Additive on the Performance Characteristics of Centrifugal and Progressive Cavity Slurry Pumps with High Concentration Fly Ash Slurries

Slurry pumps that are used in the hydraulic transportation of fly ash slurries through pipes in thermal power plants can be broadly classified into two main categories namely positive displacement and centrifugal pumps. The two types of pumps differ considerably in construction as well as in operating principle compared to the conventional pumps. The present study reports the effect of additive on the performance characteristics of centrifugal and progressive cavity screw pumps with fly ash slurries at high concentrations (above C~w~ AP 50% by weight). Mixture of sodium carbonate and Henko detergent (5:1) at a concentration of 0.2% by weight has been used as an additive. For each type of pump, the effect of additive on the performance characteristics has been experimentally evaluated at rated speed with fly ash slurries in the concentration range of 50 to 70% by weight. The pump total head, overall efficiency and pump input power as a function of flow rate have been measured. The results obtained from the centrifugal slurry pump performance show that at rated speed, the performance of the pump improves with the addition of drag reducing additive. In the case of progressive cavity screw pump, pump performance characteristics and behavior were completely different as compared to the centrifugal slurry pump. At rated speed, the performance of screw pump deteriorates with the addition of drag reducing soap solution.

Effect of Additive on the Performance Characteristics of Centrifugal and Progressive Cavity Slurry Pumps with High Concentration Fly Ash Slurries

Slurry pumps that are used in the hydraulic transportation of fly ash slurries through pipes in thermal power plants can be broadly classified into two main categories namely positive displacement and centrifugal pumps. The two types of pumps differ considerably in construction as well as in operating principle compared to the conventional pumps. The present study reports the effect of additive on the performance characteristics of centrifugal and progressive cavity screw pumps with fly ash slurries at high concentrations (above Cw AP 50% by weight). Mixture of sodium carbonate and Henko detergent (5:1) at a concentration of 0.2% by weight has been used as an additive. For each type of pump, the effect of additive on the performance characteristics has been experimentally evaluated at rated speed with fly ash slurries in the concentration range of 50 to 70% by weight. The pump total head, overall efficiency and pump input power as a function of flow rate have been measured. The results obtained from the centrifugal slurry pump performance show that at rated speed, the performance of the pump improves with the addition of drag reducing additive. In the case of progressive cavity screw pump, pump performance characteristics and behavior were completely different as compared to the centrifugal slurry pump. At rated speed, the performance of screw pump deteriorates with the addition of drag reducing soap solution.

Any link between sexual inactivity and treadle pump performance characteristics: The Malawi case

In mitigating the effects of climate change in Malawi, government promotes the use of low cost irrigation technologies to small-scale farmers, especially in wetlands where water is available. The treadle pump is one such technology. The pump is a manual water lifting device operated by feet. Although the technology has been widely accepted by small-scale farmers, there are documented reports that some farmers abandon the technology, preferring other technologies such as river diversion. One theory for the abandonment is that female farmers claim that the technology makes their male counterparts sexually inactive. This research seeks to find an explanation to the misconception. The study analyzed the physical characteristics of the treadle pump and its users.The results show that the technology is male-dominated (30% were females out of a sample of 40). The results also show that the technology is labor-intensive with very small discharge rates (an average of 0.78l/s) achieved regardless of the BMI of the operator. With such small discharge rates, in order to fulfill irrigation requirements of a crop, the operator has to pump for long hours. This exercise makes men naturally tired, perhaps making them sexually inactive as well.

인버터 주파수 제어에 따른 CO2용 수냉식 열펌프의 성능 특성

본 논문은 압축기 인버터 주파수 제어에 따른 CO2용 수냉식 열펌프의 성능 특성에 대해서 실험적으로 조사하였다. 실험장치는 압축기, 가스냉각기, 팽창밸브, 증발기, 내부 열교환기, 수액기로 구성된다. 실험장치에 사용된 모든 열교환기는 동관으로 제작된 이중관식 대향류형이다. 가스냉각기와 증발기는 2.4 m인 소시험부 6개와 4개로 각각 구성된다. 실험결과를 요약하면, 우선 증발기와 가스냉각기의 입구온도와 냉매유량이 일정한 조건하에서 압축기 인버터 주파수가 증가할수록 압축비와 토출압력이 증가한다. 또한 인버터 주파수가 증가할수록 난방능력과 압축일량은 증가하는 반면 성능계수는 감소한다. 그리고 증발기 입구 2차유체의 온도가 <TEX>$15^{\circ}C$</TEX>에서 <TEX>$25^{\circ}C$</TEX>로 증가함에 따라 압축비와 압축일량은 감소하지만 질량유량, 난방능력, 성능계수는 증가한다. 위의 이러한 경향은 종래의 프레온계 냉매 시스템의 성능 변화와 유사하다. The performance characteristics of water-chilling heat pump using CO2 for the control of inverter frequency was investigated experimentally. An experimental apparatus is consisted of a compressor, a gas cooler, an expansion valve, an evaporator and a liquid receiver. All heat exchangers used in the test rig are counter flow type heat exchangers with concentric dual tubes, which are made of copper. The gas cooler and the evaporator consist of 6 and 4 straight sections respectively arranged in parallel, each has 2.4m length. The experimental results summarize as the following: for constant inlet temperature of evaporator and gas cooler, as mass flow rate, compression ratio and discharge pressure increases with the inverter frequency. And heating capacity and compressor work increases, but coefficient of performance(COP) decreases with the inverter frequency of compressor. As inlet temperature of secondary fluid in the evaporator increases from <TEX>$15^{\circ}C$</TEX> to <TEX>$25^{\circ}C$</TEX>, compression ratio and compressor work decreases, but mass flow rate, heating capacity and COP increases with the inverter frequency of compressor. The above tendency is similar with performance variation with respect to the variation of inverter frequency in the conventional vapor compression refrigeration cycle.

A Study on the Performance Characteristics of Bubble Pump with Vertical Pipe Lengths

A Study on the Performance Characteristics of Bubble Pump with Vertical Pipe Lengths

양흡입 원심펌프에 있어서 유량변화의 영향에 관한 수치해석적 연구

A numerical simulation is carried out to investigate the effect of flow rate variation and performance characteristics of double-suction centrifugal pump. Two types of pump which have different impeller inlet breadth and curvature of the shroud line consist of six blades impeller and shroud ring. Finite-volume method with structured mesh and k-ω Shear Stress Transport turbulence model was used to guaranty more accurate prediction of turbulent flow in the pump impeller. Total head, power and overall efficiency were calculated to obtain performance characteristics of two types of pump according to the variation of flow rate. From the results, impeller having smooth curve along the shroud line obtained good performance. The lower flow rate, the more circulation region, flow unsteadiness and complicate flow pattern are observed. Complicated internal flow phenomena through impellers such as flow separation, pressure loss, flow unsteadiness and performance are investigated and discussed.

액체로켓엔진용 터보펌프의 고온 성능시험

Hot test of a full-scale turbopump for a 30-ton-thrust liquid rocket engine was carried out. The turbopump is composed of an oxidizer pump, a fuel pump, and a turbine on a single shaft. Model fluid was used in the test, that is, hot air for the turbine and water for the pumps. The turbopump was operated stably at full speed for 120 seconds. In terms of performance characteristics of pumps and turbine, the results from the turbopump assembly test are compared with those from the turbopump component tests which were performed at about half of the design rotational speed.

Numerical Investigation of Flow in a New DC Pump MHD

Electromagnetic pumps have several advantages to mechanical pumps. They offer maneuverability by directional thrust along with quietness and are conceived with an aim of eliminating all moving parts, being also free from problems of wear and tiredness of use. The flow field in the channel is treated as steady state, incompressible and fully developed laminar flow conditions. Our numerical code DCPMHD uses cylindrical coordinates (r,ϕ , z) and solves the incompressible MHD equations for magnetic vector potential A and fluid velocity V. Using finite volume method for numerical calculation. The numerical results of the performance characteristics of a DC electromagnetic pump are discussed and show that our new concept is capable to deliver bi-directional activation and have a satisfactory controllability, because of its proportional output force and input current relationship.

실내기 조합에 따른 3실형 열펌프의 냉방성능 실험연구

본 연구에서는 인버터 압축기를 적용한 3실형 멀티-열펌프 시스템의 냉방운전 시 시스템의 성능특성을 조사하였다. 시스템의 운전특성은 항온항습 기능을 가진 공기엔탈피방식의 칼로리미터를 이용하여 측정되었으며, 냉방표준 및 냉방저온 온도조건에서 실내기 조합에 따른 실험이 수행되었다. 3실형 열펌프의 실내기 조합운전에 따른 냉방 표준운전 및 냉방저온운전 시의 냉방능력, COP, P-h선도로부터, 3실형 열펌프의 운전특성과 냉방사이클의 거동을 이해하였다. 열펌프의 운전부하와 성능은 실내기 조합에 의존하므로 시스템의 능력과 사이클의 거동은 다르게 관찰되었다. 과냉도 증가와 압축일의 감소로 표준조건보다 저온조건에서 냉방능력과 COP가 더 높았다. 또한 P-h 선도를 이용하여 사이클의 운전특성도 분석하였다. In order to investigate the cooling capacity of multi-heat pump applying an inverter compressor, the experiment on the cooling performance characteristics of heat pump with 3 indoor units was performed under the cooling standard and cooling low-temperature conditions. The system data were measured by the psychrometric calorimeter. The operation characteristics and the behavior of the cooling cycle of the heat pump with 3 indoor units were understood from the cooling capacity, COP, and P-h diagram by indoor-unit combination. The operating load and performance of the multi-heat pump depends on the indoor-unit combination. The cooling capacity and COP of the low temperature condition were larger than those of the standard one. Also the cycle was analyzed by using P-h diagram.

Performance Characteristics of Electrohydrodynamic Conduction Pump in Two-Phase Loops

The electric field applied in dielectric fluids causes an imbalance in the dissociation-recombination reaction generating free space charges. The generated charges are redistributed by the applied electric field resulting in the heterocharge layers in the vicinity of the electrodes. Proper design of the electrodes generates net axial flow motion pumping the fluid. The electrohydrodynamic (EHD) conduction pump is a new device that pumps dielectric fluids utilizing heterocharge layers formed by imposition of electrostatic fields. This paper investigates the performance characteristics of EHD conduction pump in two-phase thermal control loops. The EHD twophase loop consists of an EHD conduction pump, condenser, evaporator, transport lines, and reservoir (accumulator). The tests are performed with two different loops alternating two different EHD pumps to measure the generated pressure head and the mass flowrate at various applied voltages and sink temperatures. The power consumption of EHD conduction pumps is also determined by measuring the electric current value. The de-aerated R134a and unprocessed R134a are used as the working fluid. The dependence of EHD pump performance on the fluid temperature, effects of de-aeration of working fluid, effects of electrode design, pressure loss within EHD pump, influence of the loop size (tube diameter and length) are investigated.

Performance comparison of air source heat pump with R407C and R22 under frosting and defrosting

The dynamic performance characteristics of the air source heat pump (ASHP) with refrigerants R22 and R407C during frosting and defrosting are studied. The results show that both refrigerant systems have similar performance characteristics, except that the performance of the R407C system deteriorated faster than that of the R22 system under frosting, and the performance of the R407C system attains its steady state faster than that of the R22 system after defrosting. R407C refrigerant can be used in either existing systems or in new systems that were originally designed for R22.

냉매 충전량에 따른 CO2용 수냉식 열펌프의 성능 특성에 관한 연구

The performance characteristics of water-chilling heat pump using CO₂ with respect to variation of refrigerant charge amount was investigated experimentally. An experimental apparatus is consisted of a compressor, a gas cooler, an expansion valve, an evaporator and a liquid receiver. All heat exchangers used in the test rig are counter-flow-type heat exchangers with concentric dual tubes, which are made of copper. The gas cooler and the evaporator consist of 6 and 4 straight sections respectively arranged in parallel, each has 2400 ㎜ length. The experimental results su㎜arize as the followings : As the refrigerant charge ratio of CO₂ heat pump system increases, the discharge pressure and compressor ratio increases, but mass flow rate of refrigerant decreases. Also the compressor work increases with the increase of refrigerant charge ratio. However, the heating and cooling capacity of CO₂ heat pump decreases as the refrigerant charge ratio increases. The maximum heating COP of CO₂ heat pump system presented at 0.25 refrigerant charge ratio. It is possible to confirm the optimum charge ratio of CO₂ heat pump system by the viewpoint of heating COP.

2차 유체 조건 변화에 대한 CO2용 수냉식 열펌프의 성능 특성에 관한 연구

The performance characteristics of water-chilling heat pump using with respect to variation of inlet temperature and mass flow rate of secondary fluid was investigated experimentally. An experimental apparatus is consisted of a compressor, a gas cooler, an expansion valve, an evaporator and a liquid receiver. All heat exchangers used in the test rig are counter-flow-type heat exchangers with concentric dual tubes, which ate made of copper. The gas cooler and the evaporator consist of 6 and 4 straight sections respectively arranged in parallel, each has 2.4 m length. The experimental results were summarized as the followings : As inlet temperature of secondary fluid in the gas cooler increases from to , the compressor work, heating capacity and heating COP were varied to 37.8%, -13%, -35.9%, respectively. The heating capacity, compressor work, heating COP were turned into 23.3%, 6.42%, 13.1%, respectively when ass flow rate of secondary fluid in the evaporator increases from 70 g/s to 150 g/s. The above tendency is similar with performance variation with respect to temperature variation of secondary fluid in the conventional vapor compression cycle.

Performance Analysis and Optimal Operational Planning of Water Supply Systems

From the viewpoints of energy and cost savings, it is important to rationally operate water supply systems composed of pumps, piping, and reservoirs. However, it is very difficult, because nonlinear performance characteristics of pumps and piping, discrete performance characteristics due to the combination for on/off status of pumps, and daily operational strategies of reservoirs must be considered. In this paper, a two-stage approach to the performance analysis and optimal operational planning of a water supply system is proposed. At the first stage, the performance characteristics of pumps and piping are analyzed by the Newton-Raphson method, and are optimized with respect to the combination for on/off status and revolution speed ratios of pumps by the enumeration and nonlinear programming methods, respectively. At the second stage, the daily operational strategy of the system is optimized with respect to the storage level of a reservoir by the dynamic programming method. A case study is conducted to show the effectiveness of this approach.

ターボ分子ポンプの性能試験方法に関する標準化の現状

Standardization of measurement of performance characteristics of vacuum pump in Japan is described. A draft of the standard was prepared based on the ISO 5302 (Vacuum technology—Turbomolecular pumps—Measurement of performance characteristics).

Performance Characteristics of Carbon Dioxide Heat Pump Equipped with a Two-Phase Ejector

Performance Characteristics of Carbon Dioxide Heat Pump Equipped with a Two-Phase Ejector

Evaluation of Left Ventricular Assist Device Performance and Hydraulic Force in a Complete Mock Circulation Loop

Centrifugal pump performance characteristics are vital in determining the ability of a prototype left ventricular assist device (LVAD) to meet the physiological circulation requirements of the cardiovascular system. These characteristics influence the static hydraulic forces encountered by the pump impeller, which determine the required load stiffness of suspension type bearings to minimize impeller touchdown. Performance investigations were conducted on an LVAD design while characterizing the impeller static hydraulic forces of various impeller/volute configurations. The pumps were inserted into a complete systemic and pulmonary mock circulation rig configured to provide suitable nonpulsatile or simulated pulsatile left heart failure environments. The single volute and closed shroud impeller configuration exhibited lowest radial (0.01 N) and axial (3 N) force at nonpulsatile design flow conditions, respectively. Normal hemodynamic conditions of 5.1 L/min at 94 mm Hg were re-established upon inserting the device into the left heart failure environment, where the pump operated along the nonpulsatile characteristic curve for 2200 rpm. The operational limits on this curve were dictated by the required pressure differential across the pump during systolic and diastolic periods. The reduction of left atrial pressure (25 to 8 mm Hg) indicated the alleviation of pulmonary congestion. The ability for the LVAD to support circulation in a left heart failure environment was successfully demonstrated in the mock circulation loop. The impeller hydraulic force characteristics attained will aid the bearing designer to select the best volute and impeller configuration to minimize impeller touchdown in magnetic, hydrodynamic or mechanical type bearing applications.

Performance and Development of a Miniature Rotary Shaft Pump

The development and performance of a novel miniature pump called the rotary shaft pump (RSP) is described. The impeller is made by boring a 1.168 mm hole in one end of a 2.38 mm dia shaft and cutting slots in the side of the shaft at the bottom of the bored hole such that the metal between the slots defines the impeller blades. The impeller blades and slots are 0.38 mm tall. Several impeller designs are tested over a range of operating conditions. Pump performance characteristics, including pressure rise, hydraulic efficiency, slip factor, and flow rate, are presented for several different pump configurations, with maximum flow rate and pressure rise of 64.9ml∕min and 2.1 kPa, respectively, when the working fluid is water. Potential applications include transport of biomedical fluids, drug delivery, total analysis systems, and electronics cooling.

Optimization on the performance characteristics of a three-source chemical pump affected by multi-irreversibilities

A three-source irreversible chemical pump model is established, in which three key irreversibilities usually existing in a real chemical pump system are taken into account. By using the new cyclic model, the influences of finite-rate mass transfer, mass leak, and internal dissipation of a cyclic working substance on the optimal performance of the chemical pump are revealed. The expression for optimal relation between the coefficient of performance and the rate of energy pumping is derived. Based on the optimal relationship, some new important performance bounds of the chemical pump, e.g., the maximum coefficient of performance and the corresponding rate of energy pumping, the maximum rate of energy pumping and the corresponding coefficient of performance, and so on, are obtained and the optimal operating region of the chemical pump is determined. Moreover, the optimal chemical potentials of the cyclic working substance and the optimal mass-exchange times in the three mass-exchange processes are further discussed. The results obtained in the present paper can provide some new theoretical guidance for the optimal design and development of a class of chemical pumps.

Performance characteristics of single-stage disk-type drag pump

The direct simulation Monte Carlo (DSMC) method is applied to investigate steady and unsteady flow fields of a single-stage disk-type drag pump. Two different kinds of pumps are considered: the first one is a rotor–rotor combination, and the second one is a rotor–stator combination. Each of rotor and stator has 10 Archimedes’ spiral blades, respectively. In the present DSMC method, the variable hard sphere molecular model with the no time counter technique is employed to simulate the molecular collision kinetics. For simulation of diatomic gas flows, the Borgnakke–Larsen phenomenological model is adopted to redistribute the translational and internal energies. Some experimental works are carried out to verify the numerical results. Good agreement between the numerical results and the experimental data is shown.