scholarly journals ANALYSIS OF THE HEAT PUMP OPERATION IN THE LOW-TEMPERATURE RECTIFICATION SYSTEM OF PROPANE-BUTANE MIXTURE

2021 ◽  
pp. 3-8
Author(s):  
Larisa Morozyuk ◽  
Evgeny Kostenko
Keyword(s):  
Low Temperature ◽  
Heat Pump ◽  
Distillation Column ◽  
Flow Diagram ◽  
Thermodynamic Efficiency ◽  
Pump System ◽  
Pump Operation ◽  
Heat Pump System ◽  
Butane Mixture ◽  
Propane Butane

The article presents the results of the analysis of the operation of a heat pump in the system of low-temperature rectification of a propane-butane mixture. High-purity propane is obtained from a propane-butane mixture. A "rectification column-heat pump" system is proposed, which transforms the heat removed during the cooling of the component in the upper part of the column into heat absorbed during heating of the bottoms. In accordance with the energy balance of the system, it has been established that part of the heat pump condensation is not used in the distillation column, but is removed to the environment. The heat pump flow diagram contains one evaporator and two condensers. The operation of the heat pump is evaluated from the standpoint of thermodynamics – by the method of energy analysis of the cycle with R134 and R290 working substances, It has been established that the low thermodynamic efficiency of the heat pump is determined by external irreversible losses in the condensers and the evaporator The advantages of R290 as a working substance of the heat pump have been proved and the required theoretical volumetric capacity of the compressor has been determined.

Determination of Heat Transfer Characteristics of Solar Thermal Collectors as Heat Source for a Residential Heat Pump

2016 ◽  
Vol 138 (4) ◽  
Author(s):  
Maarten G. Sourbron ◽  
Nesrin Ozalp
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Low Temperature ◽  
Heat Source ◽  
Heat Pump ◽  
Solar Collector ◽  
Heat Transfer Characteristics ◽  
Pump System ◽  
Heat Pump System ◽  
Temperature Heat

With reducing energy demand and required installed mechanical system power of modern residences, alternate heat pump system configurations with a possible increased economic viability emerge. Against this background, this paper presents a numerically examined energy feasibility study of a solar driven heat pump system for a low energy residence in a moderate climate, where a covered flat plate solar collector served as the sole low temperature heat source. A parametric study on the ambient-to-solarfluid heat transfer coefficient was conducted to determine the required solar collector heat transfer characteristics in this system setup. Moreover, solar collector area and storage tank volume were varied to investigate their impact on the system performance. A new performance indicator “availability” was defined to assess the contribution of the solar collector as low temperature energy source of the heat pump. Results showed that the use of a solar collector as low temperature heat source was feasible if its heat transfer rate (UA-value) was 200 W/K or higher. Achieving this value with a realistic solar collector area (A-value) required an increase of the overall ambient-to-solarfluid heat transfer coefficient (U-value) with a factor 6–8 compared to the base case with heat exchange between covered solar collector and ambient.

The Heating Coefficient Experimental Analysis of Solar Water-Assisted Low Temperature Air Source Heat Pump System

2014 ◽  
Vol 953-954 ◽  
pp. 136-143
Author(s):  
Jin Shun Wu ◽  
Yue Bo Hu ◽  
De Zhi Hu ◽  
Hong Wei Liu
Keyword(s):  
Comparative Analysis ◽  
Low Temperature ◽  
Heat Pump ◽  
Compression Ratio ◽  
Hot Water ◽  
Pump System ◽  
Heat Pump System ◽  
Heating Efficiency ◽  
Evaporation Temperature ◽  
Air Source Heat Pump

In winter,Many families use air source heat pump because of the low evaporation temperature of the system, resulting in lower heating efficiency of system. To solve this problem, the low temperature solar assisted hot water was added to the project which is on the basis of air source heat pump, and the system has been tested. After analysis of the collection efficiency of solar collectors at low temperatures and comparative analysis of the temperature cycle, pressure, energy consumption of the low-temperature solar-assisted systems and air source heat pump system, the optimal collector temperature and law of heat pump refrigerant cycle changes of the system were obtained. Theoretically, comparative analysis of low temperature air source heat pumps and solar hot water secondary air source heat pump compression ratio and COP. It gives the key parameters affecting the compression ratio and COP, pointing out ways to improve the heat pump COP. Finally, a key measure to improve the thermal performance of the unit system is proposed, to provide a reference for future practical applications and research. Foreword Air source heat pump in ambient air contains rich low grade solar potential as a source of heat, it has inexhaustible characteristics [1] . The main reason for restricting the use of air source heat pump in northern area of our country is when the outdoor air temperature is low in winter, the outdoor coil frost severe heating efficiency air source heat pump is greatly reduced. Martinez suggested experimental study on the application of solar radiant floor heating systems , solar water temperature is 50-60°C, low efficiency, especially when overcast snow lower system efficiency [2] .In view of the outdoor coil frosting problem, direct expansion solar assisted heat pump water heater system using the proposed by Li Yuwu, from a certain extent alleviated the problem of heat in winter for coil winter fros, improving the heating coefficient and improved the operating characteristics of the unit. However, this system requires the direct absorption of heat in air tube, and the specific heat of air is small, difficult to heat storage, illumination by solar radiation impact, unstable system operation [3]. Based on the above issues, for the low-level office building , the new rural residential , this study presents low temperature solar auxiliary air source heat pump system , the device uses low-temperature solar hot water heat pump system as low , both full use of solar energy , but also eliminates the original system frost problems and improve the efficiency of solar collectors and heat set to improve the evaporation temperature of the evaporator , thereby increasing the compression ratio of the heat pump unit .

scholarly journals Performance and Optimization Study of R290 as Alternative Refrigerant for R22 in Low Temperature Heat Pump System

2021 ◽  
Vol 2108 (1) ◽  
pp. 012089
Author(s):  
Yun Zhang ◽  
Cichong Liu ◽  
Wanyong Li ◽  
Junye Shi ◽  
Jiangping Chen
Keyword(s):  
Low Temperature ◽  
Heat Pump ◽  
Pump System ◽  
Heat Pump System ◽  
Exhaust Temperature ◽  
Discharge Temperature ◽  
Temperature Environment ◽  
Temperature Heat ◽  
Overall Performance ◽  
Temperature And Pressure

Abstract This paper mainly studies the replacement performance of R290 in R22 low temperature heat pump system from the experimental point of view. By comparing the performance differences under different working conditions, it is found that when R22 is directly extracted from the original system and filled with R290, the heat capacity and COP of the system are attenuated, and the compressor discharge temperature and pressure of the R290 system are higher than those of the original R22 system in low temperature environment. Through the analysis of the system components, it can be considered that the main reason for the above phenomenon is that the compressor displacement of the R22 system is too large and does not match the R290 system. Therefore, in order to meet the safety requirements of the system and improve the overall performance of R290 in the low temperature heat pump system at the same time, it is considered to replace the compressor with a smaller displacement which is more matched with R290 in the system. The experimental results show that the compressor displacement optimization of the R290 low temperature heat pump system can effectively reduce the exhaust temperature and pressure of the system and improve the overall performance of the system. The COP of the optimized R290 low temperature heat pump system is 6.5% higher than that of the original R22 system, and the exhaust temperature in the low temperature environment is reduced by 36% to below 80 C.

Performance Prediction of a Sub-Slab Heat Exchanger for Geothermal Heat Pumps

1998 ◽  
Vol 120 (4) ◽  
pp. 282-288 ◽  
Author(s):  
K. Den Braven ◽  
E. Nielson
Keyword(s):  
Soil Temperature ◽  
Heat Pump ◽  
Flow Direction ◽  
Heat Pumps ◽  
Heat Extraction ◽  
Fluid Temperature ◽  
Geothermal Heat ◽  
Pump System ◽  
Pump Operation ◽  
Heat Pump System

A large portion of the installation cost of a ground-coupled heat pump system is for the excavation necessary for ground coil placement. One possible method of reducing this cost is to place the ground coils beneath the slab floor of the building. This configuration of ground coil placement has not been specifically addressed in previous research. Freezing of the soil must be avoided in such a system. To simulate the temperature response of the surrounding soil to heat pump operation, a computer model was developed which incorporates line source theory in the form of a system of rings. The fluid temperature change along the length of the coil was used to determine the distribution of the ground load throughout the ring system. The model includes an adiabatic upper boundary, seasonal soil temperature variation, and thermal interference throughout the system. Using these results, the minimum soil temperature over a season was predicted. Based on these results, design recommendations for ground coil installation are provided based on available area, soil type, heat extraction rate, depth of coil beneath the slab floor, and depth of slab floor below grade. These include recommendations for pipe spacing, flow direction, and a method to determine whether this type of system is feasible for installation in a particular location.

scholarly journals Experimental study of heat pump type air-water for heating system performance

2019 ◽  
Vol 112 ◽  
pp. 01007 ◽  
Author(s):  
Penka Zlateva ◽  
Krastin Yordanov
Keyword(s):  
Ambient Temperature ◽  
Heat Pump ◽  
Heating System ◽  
Heating Regime ◽  
Operational Mode ◽  
Operating Characteristics ◽  
Pump System ◽  
Pump Operation ◽  
Heat Pump System ◽  
Air Temperatures

The operation of an air-to-water heat pump system providing space heating production for an administrative building in Varna has been explored. For this purpose, discontinuous operational mode of the heat pump system during wintertime is considered. Study has been performed by use of real values for external ambient temperature and operating characteristics of the heat pump system. The seasonal efficiency of the heat pump operation has been calculated. Also, the minimal external ambient temperature until the heat pump may work in heating regime and operation duration at outdoor air temperatures higher than the design air temperature can be determined. The economic analysis of the heat pump system exploitation has been made finally.

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