Instability Prediction of Valve Motion and Internal Flow in Novel Large-scale Reciprocating Pump

Yi Ma,Yutao Chen,He Zhang,Huashuai Luo,Hongying Deng 한국유체기계학회 2019 International journal of fluid machinery and syste Vol.12 No.1

To study the transient valve motions and flow pulsation of novel five-cylinder double-acting reciprocating pump, the theoretical analysis and computational fluid dynamics (CFD) method are employed to investigate the full-cycle working process of the pump. The theoretical models describing the motions and flow rates of hydraulic end are established for reciprocating pump under the actions of piston and valves. The open-close behavior of suction and discharge valves, internal turbulent flow and pulsation characteristics of the pump are studied and the effects of crank speed on those are analyzed in detail. The results show that the valves of reciprocating pump open and close quickly and non-linearly with various degrees of striking velocities and lag phenomena. Through the time and frequency domain results of flow pulsation, the single-cavity frequency is the dominant frequency. The most obvious amplitude appears for discharge flow pulsation, which gradually increases with crank speed. The results could provide useful information for the optimization of reciprocating pumping systems.

왕복동식 펌프의 점진적인 성능 저하 진단을 위한 FPGA 기반 에뮬레이터 구현에 관한 연구

임상선(Sang Sun Lim),김우식(Wooshik Kim),김태윤(Tae Yun Kim),채장범(Jang Bom Chai) 대한기계학회 2017 大韓機械學會論文集A Vol.41 No.1

이 논문의 목적은 원자력 발전소의 급수 펌프인 왕복동식 펌프의 연속적인 사용으로 인한 점진적인 성능저하의 정도를 진단하는 방법을 개발하는 것이다. 일반적으로 이러한 점진적인 성능 저하는 너무 서서히 진행되기 때문에 기존의 진단 방법으로는 그 성능 저하의 정도를 판단하기 어렵다. 하지만 정상 상태의 파라미터들을 제공하는 기계가 있다면, 현재의 상태와 비교하여 성능 저하의 정도를 파악하는 것이 가능해 진다. 이 논문은 점진적인 성능 저하를 식별하는데 사용할 수 있는 새로운 방법을 제안한다. 건강한 상태의 펌프의 정보를 제공하는 에뮬레이터를 FPGA 사용하여 개발하는 과정을 보이고, 실제 펌프로부터 수집한 데이터와 비교하여 에뮬레이터가 동작한다는 것을 보인다. The purpose of this study is to develop a method for diagnosing the degree of gradual degradation of a reciprocating pump caused by continuous use as a water supply pump in a nuclear power plant. Normally, the progress of such degradation is too slow to be noticed. Hence, it is difficult to determine the degree of degradation using the existing diagnostic methods. In this paper, we propose a new method by which the normal state and the degraded state of the pump can be differentiated, so that the degree of degradation can be identified. First, an emulator was developed using FPGA by providing the parameters of the pump under normal state, so that the emulator generates the information of the pump in the healthy state. Then, by comparing this information with the parameters received from various output sensors of the emulator during the current state, it is possible to identify and measure the degree of gradual degradation. This paper presents some of the results obtained during the development process, and results that show how the emulator operates, by comparing the data collected from an actual pump.

Estimation of Probability Density Functions of Damage Parameter for Valve Leakage Detection in Reciprocating Pump Used in Nuclear Power Plants

이종겸,김태윤,Hyun Su Kim,채장범,이진우 한국원자력학회 2016 Nuclear Engineering and Technology Vol.48 No.5

This paper presents an advanced estimation method for obtaining the probability density functions of a damage parameter for valve leakage detection in a reciprocating pump. The estimation method is based on a comparison of model data which are simulated by using a mathematical model, and experimental data which are measured on the inside and outside of the reciprocating pump in operation. The mathematical model, which is simplified and extended on the basis of previous odels, describes not only the normal state of the pump, but also its abnormal state caused by valve leakage. The pressure in the cylinder is expressed as a function of the crankshaft angle, and an additional volume flow rate due to the valve leakage is quantified by a damage parameter in the mathematical model. The change in the cylinder pressure profiles due to the suction valve leakage is noticeable in the compression and expansion modes of the pump. The damage parameter value over 300 cycles is calculated in two ways, considering advance or delay in the opening and closing angles of the discharge valves. The probability density functions of the damage parameter are compared for diagnosis and prognosis on the basis of the probabilistic features of valve leakage.

유한요소 해석을 이용한 액화수소 펌프 누설량 예측

김현세,함영복 한국수소및신에너지학회 2023 한국수소 및 신에너지학회논문집 Vol.34 No.3

Until recently, ships, automobiles, and drones using hydrogen energy are being actively researched. In addition, stations and facilities for hydrogen supply are being developed widely. Among them, a hydrogen pump is necessary for compressing it and transfer to other stations. The liquid hydrogen pump is operated at very high pressure up to 90 MPa. In our research, a reciprocating plunger pump is studied. Especially, a leakage in a liquid hydrogen pump is predicted using a finite element method. As a result, it was found that leak mass flow rates changed from 0.09 to 2.20 kg/h, when the gaps were given from 2 to 6 μm. Thus pump efficiencies were calculated from 99.9 to 97.9%, when the gaps changed from 2 to 6 μm. These results are useful for the design of the liquid hydrogen pump.

Hexagonal reciprocating pump: advantages and weaknesses

Milan Stanko,Michael Golan 한국유체기계학회 2013 International journal of fluid machinery and syste Vol.6 No.3

This paper reports the 1-D fluid transient simulation results of the discharge flow conditions in a 6-cylinder reciprocating slurry pump. Two discharge manifold configurations are studied comparatively; a case with a hexagon shaped discharge manifold where each cylinder discharges at a single vertex, and a case where all the cylinders discharges are lumped together into a tank shaped manifold. In addition, the study examines the effect of two pulsation mitigation measures in the case of hexagonal manifold; a single inline orifice in one of the hexagon sides and a volumetric dampener at the manifold outlet. The study establishes the pressure and flow fluctuation characteristics of each configuration and decouples the pulsation characteristics of the pump and the discharge manifold.

Hexagonal reciprocating pump: advantages and weaknesses

Stanko, Milan,Golan, Michael Korean Society for Fluid machinery 2013 International journal of fluid machinery and syste Vol.6 No.3

This paper reports the 1-D fluid transient simulation results of the discharge flow conditions in a 6-cylinder reciprocating slurry pump. Two discharge manifold configurations are studied comparatively; a case with a hexagon shaped discharge manifold where each cylinder discharges at a single vertex, and a case where all the cylinders discharges are lumped together into a tank shaped manifold. In addition, the study examines the effect of two pulsation mitigation measures in the case of hexagonal manifold; a single inline orifice in one of the hexagon sides and a volumetric dampener at the manifold outlet. The study establishes the pressure and flow fluctuation characteristics of each configuration and decouples the pulsation characteristics of the pump and the discharge manifold.

가스 인젝션을 이용한 가변속 왕복동 압축기가 적용된 열펌프의 냉방성능에 관한 연구

장진혁(Jinhyuk Jang),이대희(Daehui Lee),이진호(Jinho Lee) 대한기계학회 2012 대한기계학회 춘추학술대회 Vol.2012 No.5

고온의 외기온도에서 운전되는 열펌프의 냉방 성능향상과 신뢰성 확보는 매우 중요하다. 가스 인젝션 사이클은 냉방능력과 신뢰성 향상을 위해 효과적인 기술이다. 본 연구의 목적은 왕복동 압축기를 사용하는 열펌프에 가스 인젝션 사이클을 적용하여 신뢰성 확보하고, 냉방 성능을 향상 시키는데 있다 가변속 왕복동 압축기와 바이패스 라인에 EEV를 설치하여 운전속도와 바이패스 라인의 EEV 개도율 변화를 통해 운전 특성과 냉방 성능변화를 알아보았다. 이를 통해 압축기 출구 압력과 온도가 각각 최대 36.5%와 52.1%로 하강하였으며, 냉방 COP는 최대 10%가 상승하였다. Vapor injection cycle is used to enhance cooling performance and reliability of heat pump operate under high temperature cooling. The purpose of this study is improving cooling performance and ensuring reliability of heat pump. Gas injection cycle is applied to heat pump with variable speed reciprocating compressor. Operating characteristics and cooling performance of heat pump were discussed on varying compressor frequency and open rate of EEV in bypass line. As a result, compressor exit pressure and temperature were decreased maximum 36.5% and 52.1% respectively and cooling COP is increased maximum 10%.

Influence of Crank Rod Ratio on the Flow Pulsation and Slider Inertial Force of the New Reciprocating Pump

Qiang Li,Limin Meng,Qi Zhou 한국유체기계학회 2024 International journal of fluid machinery and syste Vol.17 No.1

Aiming at the problems of complex structure and unreasonable parameter setting leading to high flow pulsation rate of traditional hydraulic reciprocating pump in high pressure systems, a new reciprocating pump model with a simple structure was proposed based on the principle of variable orifice of mechanical iris mechanisms.First, based on the model of the new reciprocating pump, the analysis equation for flow pulsation is derived. Secondly, Fluent software is used to perform fluid simulation on the new reciprocating pump, verifying the correctness of the pulsation equation and analyzing the pressure distribution contour map and velocity distribution contour map of the internal flow field of the new reciprocating pump during the cycle. Finally, according to the analysis equation, the variation curve of flow pulsation rate with the number of new reciprocating pumps and the crank-connecting rod ratio is obtained, and optimization suggestions for the parameter setting of the crank-connecting rod in the new reciprocating pump are proposed. The results show that: The derived analytical formula for flow pulsation of the new reciprocating pump is correct. The flow pulsation rate increases with the increase of the crank-connecting rod ratio, and when the number of new reciprocating pumps is 5, the influence of the crank-connecting rod ratio on the flow pulsation rate reaches 87%. The degree of oscillation of the inertial force experienced by the slider decreases as the crank rod ratio decreases. To increase the maximum and minimum values of the instantaneous flow rate and reduce the oscillation degree of the inertial force experienced by the slider, the crank rod ratio should be controlled within the range of 0.2 to 0.3. This new reciprocating pump enriches the structure of the pump and provides certain references for reducing flow pulsation in reciprocating pumps as well as decreasing the oscillation degree of the inertial force experienced by the slider.

Performance Analysis of Cost Effective Portable Solar Photovoltaic Water Pumping System

Richa Parmar,Chandan Banerjee,Arun K. Tripathi 한국태양광발전학회 2021 Current Photovoltaic Research Vol.9 No.2

Solar water pumping system (SWPS) is reliable and beneficial for Indian farmers in irrigation and crop production without accessing utility. The capability of easy installation and deployment, makes it an attractive option in remote areas without grid access. The selection of portable solar based pumps is pertaining to its longer life and economic viability due to lower running cost. The work presented in this manuscript intends to demonstrate performance analysis of portable systems. Consequent investigation reveals PSWS as the emerging option for rural household and marginal farmers. This can be attributed to the fact that, a considerable portion (around 45.7%) of the country’s land is farmland and irrigation options are yet to reach farmers who entirely rely on rain water at present for harvesting of the crops. According to census 2010-2011 tube wells are the main source for irrigation amongst all other sources followed by canals. Out of the total 64.57-million-hectare net irrigation area, 48.16% is accounted by small and marginal holdings, 43.77% by semi-medium and medium holdings, and 8.07% by large holdings. As per 2015-16 census data, nearly 100 million farming households would struggle to make ends meet. The work included in this manuscript, presents the performance of different commercial brands and different technologies of DC surface solar water micro pumping systems have been studied (specifically, the centrifugal and reciprocating type pumps have been considered for analysis). The performance of the pumping systems has been analyzed and data is evaluated in terms of quantity of water impelled for specific head. The reciprocating pump has been observed to deliver the best system efficiency.

혈류 유동 실험을 위한 맥동식 펌프 설계

주윤하(Y. H. Joo),전철웅(C. W. Jun),이다혜(D. H. Lee),한효주(H. J. Han),안진효(J. H. An),이종민(J. M. Lee),박철우(C. W. Park) 대한기계학회 2011 대한기계학회 춘추학술대회 Vol.2011 No.10

In the present study, we performed design processes of reciprocating pump to make pulsatile flow for simulation of aortic blood flow in arteries. To design a pulsatile pump, we firstly calculated the pressure for working fluid in a cylinder accurately based on fundamentals of fluid mechanics. According to the pressure expectation, every compartments, such as piston, crank shaft and gear, were designed to overcome plastic deformation. As a result, we evaluated the power requirement effectively for a reciprocating pump motor selection.