R32 냉매를 사용하는 히트 펌프의 전자식 팽창 밸브 질량유량 상관식 평가

김민규,정지환 대한설비공학회 2022 설비공학 논문집 Vol.34 No.7

The internal flow of an electronic expansion valve is complex. Many researchers have proposed mass flow correlations in various ways to predict the mass flow through an electronic expansion valve. However, the evaluation of the correlation equation was insufficient, and in this paper, data of the R32 heat pump system was acquired to evaluate correlations. The orifices of the electronic expansion valve used in the experiment were 2.40 mm and 1.65 mm, respectively. The acquired data were inputted into the existing correlation and compared. The correlational MAPE evaluated from the data of the electronic expansion valve with an orifice diameter of 2.40 mm was from 9.07% to 334.52%, SD showed from 4.34% to 206.37%. Correlated MAPE evaluated from the data of the electronic expansion valve with orifice diameter of 1.65 mm was from 24.07% to 160.82%, SD was from 6.00% to 177.11%. As a cause analysis, there is a difference in the geometric shape and size of the electronic expansion valve. Also, the change in physical properties depending on the refrigerant was one of the causes of the error. 지난 기간 동안 연구자들은 다양한 운전조건과 냉매에 대한 전자식 팽창 밸브 유량 상관식을 개발해왔다. 각자 다른 방식을 통하여 새로운 유량 상관식을 제시하였지만, 이에 대한 평가는 여전히 부족했다. 본 논문은 이러한 유량 상관식의 평가를 위해서 R32 냉매를 사용하는 히트펌프를 사용하여 넓은 운전조건과 내부 오리피스 지름이 다른 EEV를 사용하여 데이터를 취득하였다. 이 데이터를 이용하여 제시된 상관식에 적용하고 결과를 분석하였다. 현재까지 개발된 냉매 유량 상관식은 실험 데이터에 의존하기 때문에 제한된 운전 조건과 냉매, 전자식 팽창 밸브의 기하학적 조건에 영향을 받는다. 전자식 팽창 밸브의 내부 오리피스의 지름이 서로 다른 2개의 EEV에 대해서 실험한 데이터를 통해 비교한 결과 EEV #1(D: 2.40 mm)의 비교 결과는 Park et al.(10)의 상관식 평가결과가 MAPE 9.07%, SD 10.01%를 나타내어 가장 실험값과 유사하게 예측하였다. EEV #2(D: 1.65 mm)의 비교 결과는 Tian et al.(13)의 상관식 평가결과는 MAPE 24.07%, SD 10.21%를 나타내어 가장 실험값과 유사하게 예측하였다. 분석 결과 전자식 팽창 밸브의 기하학적 형상 및 수치의 차이와 냉매에 차이에 따른 운전조건 및 물성치의 차이로 인해 오차가 발생할 수 있다.

온도식팽창밸브의 전자식팽창밸브로의 대체 가능성에 관한 연구

한도영(Doyoung Han),정성욱(Seongwoock Jeong) 대한설비공학회 2006 대한설비공학회 학술발표대회논문집 Vol.2006 No.6

For the precise superheat temperature control of an air conditioner, an electronic expansion valve may be used instead of a thermal expansion valve. In this paper, technical and economical aspects of expansion valves were studied in order to find out the possibility to use an electronic expansion valve to replace a thermal expansion valve.

전자팽창밸브 작동특성에 대한 실험적 연구

윤소남 (Y. S. Nam),함덕용 (D. Y. Ham),한유리 (Y. Han),이근우 (K. W. Lee),정병홍 (B. H. Jeong) 한국동력기계공학회 2009 한국동력기계공학회 학술대회 논문집 Vol.2009 No.6

This study presents the possibility of the refrigerant control using electronic expansion valve which is operated by stepping motor. The electronic expansion valve is a type of flow control equipment that is a combination of a poppet, a positioner, three reduction gears and a stepping motor. The poppet modulates orifice its opening to maintain the controlled refrigerant flow. So, pitch control of the positioner and pulse control of the three reduction gears are very important design parameters for performance improvement of this study object valve. In this paper, the effects of the nonlinearity, the hysteresis on the performance and flow rate characteristics of electronic expansion valve were investigated. The input pulse of stepping motor, displacement characteristics and flow rate characteristics of this valve were analyzed through the experimental setup.

에어컨용 팽창밸브 개발에 관한 연구

윤소남(S. N. Yun),함덕용(D. Y. Ham),한유리(Y. Han),정병홍(B. H. Jeong) 유공압건설기계학회 2008 유공압건설기계학회 학술대회논문집 Vol.2008 No.10

An air conditioner(air conditioning system) is a cooling equipment that has a the process of the one-cooling cycle such as compression, condensation, expansion and evaporation. Expansion process is operated by expansion valve that is a kind of mass flow control component. The characteristics of a expansion valve design parameters such as linearity, repeatability and hysteresis are very important because these parameters affect the variation of the COP(Coefficient of Performance). This paper presents the static and dynamic characteristics of a bellows type expansion valve. The static and dynamic analysis by experiments and the structure analysis by FEM tool were accomplished for development of the new structure of expansion valve. The torque characteristics of the stepping motor and the displacement variation of the poppet valve were also analyzed through the experimental setup. In this study, the new structure of the expansion valve through the theoretical analysis and experiment was suggested. And it was confirmed that the suggested model is proper to apply in the air conditioning system.

텐덤형 냉방시스템의 안전운전을 고려한 압축기와 전자팽창밸브 제어

한도영(Doyoung Han),김재현(JaeHyun Kim) 대한설비공학회 2006 대한설비공학회 학술발표대회논문집 Vol.2006 No.6

Capacities of a tandem-type air-conditioner may be modulated by turning on and off of multiple compressors, and adjusting the position of a electronic expansion valve. In this study, control algorithms for compressors and a electronic expansion valve were developed by using fuzzy logics. The pressure control algorithm was also developed for the safe operation of compressors. There algorithms were implemented in a test lab and proved to be effective for the control of indoor air temperature and superheat temperature.

전기자동차 히트펌프 시스템용 냉매 제어 밸브 개발

김준호(Junho Kim),기정진(Jungjin Ki),김기목(Kimok Kim),홍태호(Taeho Hong) 한국자동차공학회 2023 한국자동차공학회 부문종합 학술대회 Vol.2023 No.5

The thermal management system of electric vehicles is very different from that of conventional internal combustion engine vehicles. Improving the efficiency in cooling and heating of the air conditioning system of an electric vehicle driven only with the electric energy of a battery has become a very important issue. In particular, the heat pump system to deal with the problem of reducing driving range due to excessive power consumption during heating has become a basic technology for most electric vehicles. As the number of refrigerant components in a heat pump system increase and the complexity of a circuit increases, it is required to apply several refrigerant control valves, including electronic expansion valve. In this study, electronic expansions valve which has a disk type expansion mechanism were developed, 3way and 4way functions were implemented to respond to various circuits, and flow control characteristics were optimized. And it was applied to the heat pump system to evaluate the controllability, and the heating performance was confirmed under various operating mode.

전자팽창밸브 제어성능 모사용 증발기 동특성 모델링

신영기(Younggy Shin),조수(Soo Cho),태춘섭(Choon-Seob Tae),장철용(Cheol-Yong Jang) 대한설비공학회 2007 설비공학 논문집 Vol.19 No.2

Controlling superheat of indoor units associated with a multi-type heat pump is one of difficult tasks to be addressed. This study suggests a dynamic model of an evaporator based on heat and mass balance. Thermodynamic properties are calculated by a commercial software, Refprop, The model is programmed in MFC Visual C++ for controller interface in real-time mode. The simulation results shows that PI control works for a narrow range of superheat. Beyond the range, the temperature behavior of the refrigerant is quite nonlinear mainly due to phase change. Thus, it is concluded that PI control of superheat has to be supplemented by nonlinear control ideas to avoid saturation and excessive superheat.

항공기 외장형 정찰 장비용 냉각 시스템의 성능 특성에 관한 실험적 연구

정대윤,이행복,Jung, Daeyoon,Lee, Hang Bok 한국군사과학기술학회 2013 한국군사과학기술학회지 Vol.16 No.1

In this paper, we have proposed a vapor cycle refrigeration system as a cooling system to provide cooling air to the aircraft external reconnaissance stores. In the proposed vapor cycle system, receiver which prevents refrigerant from subcooling was eliminated and thermal expansion valve was replaced with electronic expansion valve. The vapor cycle refrigeration system is aimed to provide cooling air to the reconnaissance stores which is added to the aircraft in the form of external store. The wide temperature range of ambient air from the flight conditions can decrease the cooling performance and can make the refrigeration system unstable in low ambient temperature. Performance characteristics of the vapor cycle refrigeration system has been experimented under air conditions which is derived from the flight envelope. From the experiments, the vapor cycle refrigeration system has been proved to provide enough cooling air to the reconnaissance equipment and to be stable under all the flight conditions.

냉동사이클의 열역학 특성에 관한 실험적 연구

Li Hua,이동우(D. W. Lee),정석권(S. K. Jeong) 한국동력기계공학회 2005 한국동력기계공학회 학술대회 논문집 Vol.- No.-

To obtain high efficiency, high intelligence, and energy saving for refrigeration system, the optimum control of the refrigeration system is inevitable. The conventional control schemes are mainly based on representative two control methods. One is capacity control for room temperature control and energy saving by compressor speed variation. The other is superheat control for enhancing coefficient of performance of the refrigeration system by varying opening angle of an electronic expansion valve. They have been controlled not be coupled but be separated. However, the refrigeration system's elements are deeply connected with the pipe each other, so optimum control is not easy. This paper presents an experimental study for heat dynamic characteristics analysis of the refrigeration system to control evaporator superheat and compressor capacity with optimum.

퍼지알고리즘을 사용한 냉매압력제어

한도영(Doyoung Han),박승호(Seungho Park) 대한설비공학회 2009 대한설비공학회 학술발표대회논문집 Vol.2009 No.-

Control methods for a CO₂ air-conditioning system should be different because of CO₂'s unique properties as a refrigerant. Especially, the high-side pressure of a CO₂ system should be controlled for the effective operation of a system. In this study, a fuzzy algorithm was developed for the control of the refrigerant pressure. The refrigerant pressure difference and its slope were used as input variables and the control signal difference for a electronic expansion valve was used as an output variable. The Min-Max method was used as an inference machine and the weight centroid method was used as a defuzzification tool. In order to identify the effectiveness of the control algorithm, an initial start-up test, an indoor temperature setpoint step change test, and an outdoor air disturbance test, were performed. Test results showed the good control of a CO₂ air-conditioning system with stable control signals. Therefore the pressure control algorithm developed for this study may be practically applied for the control of an electronic expansion valve.