Performance of multiple mini-tube heat exchangers as an internal heat exchanger of a vapor-injection cycle heat pump

2015 ◽  
Vol 52 (4) ◽  
pp. 741-752
Author(s):  
Jin Yong Jang ◽  
Ji Hwan Jeong
Keyword(s):  
Heat Exchanger ◽  
Heat Pump ◽  
Heat Exchangers ◽  
Internal Heat ◽  
Internal Heat Exchanger ◽  
Vapor Injection ◽  
Injection Cycle

scholarly journals Experimental study on vapor injection air source heat pump with internal heat exchanger for electric bus

2019 ◽  
Vol 158 ◽  
pp. 4147-4153 ◽  
Author(s):  
Xinxin Han ◽  
Huiming Zou ◽  
Hongbo Xu ◽  
Changqing Tian ◽  
Wei Kang
Keyword(s):  
Experimental Study ◽  
Heat Exchanger ◽  
Heat Pump ◽  
Internal Heat ◽  
Air Source Heat Pump ◽  
Internal Heat Exchanger ◽  
Electric Bus ◽  
Vapor Injection

Experimental Validation of On-Field Measurement Method for a Heat Pump System with Internal Heat Exchanger

2016 ◽  
Vol 24 (02) ◽  
pp. 1650011 ◽  
Author(s):  
Maria Goossens ◽  
Philippe Riviere ◽  
Cedric Teuillieres ◽  
Cong Toan Tran ◽  
Odile Cauret ◽  
...  
Keyword(s):  
Heat Exchanger ◽  
Mass Flow Rate ◽  
Heat Pump ◽  
Mass Flow ◽  
Flow Rate ◽  
Measurement Method ◽  
Internal Heat ◽  
Injection System ◽  
Internal Heat Exchanger ◽  
Vapor Injection

Determining the on-field heating capacity and coefficient of performance (COP) of residential air-to-air heat pumps (HPs) is problematic, given that measuring accurately the enthalpy and, specifically, the mass flow rate of air is challenging. This paper validates a promising on-field performance measurement method for HPs with an internal heat exchanger (IHX) as vapor injection system using experimental data obtained from air-to-water heat pump prototype in several operating conditions. The method is based on refrigerant fluid measurements and component energy/mass balances. Nonintrusive sensors, such as surface temperature sensors, are used to estimate pressure and refrigerant mass flow rate in different types of heat pump systems, including air-to-air. Obtained results compared with intrusively measured reference values in steady-state conditions are in good agreement, suggesting that a comprehensive performance analysis can be conducted in already-installed high efficiency residential IHX air-to-water HPs, as well as internal heat exchanger air-to-air HPs.

scholarly journals Numerical study on the influence of internal heat exchanger in transcritical CO2 heat pumps under optimal pressure conditions

2021 ◽  
Vol 2116 (1) ◽  
pp. 012098
Author(s):  
F Illán-Gómez ◽  
J R García-Cascales ◽  
F J Sánchez-Velasco ◽  
V Sena-Cuevas ◽  
R Otón-Martínez
Keyword(s):  
Heat Exchanger ◽  
Heat Pump ◽  
Strong Influence ◽  
Numerical Study ◽  
Internal Heat ◽  
Heat Pumps ◽  
Operating Conditions ◽  
Water Heater ◽  
Internal Heat Exchanger ◽  
Heat Pump Water Heater

Abstract This paper presents a numerical study on the influence of internal heat exchanger (IHX) exchanging surface in the performance of a transcritical CO2 heat pump water heater at different operating conditions. Five different IHX geometries and four different evaporation temperatures have been studied with water temperature ranging from 10 °C to 60 °C at the gas cooler inlet. The results show a strong influence of IHX characteristics on system’s performance.

Development of a Novel Two-Stage Heat Pump Clothes Dryer

2014 ◽  
Author(s):  
Tao Cao ◽  
Jiazhen Ling ◽  
Yunho Hwang ◽  
Reinhard Radermacher
Keyword(s):  
Heat Exchanger ◽  
Heat Pump ◽  
Energy Savings ◽  
Design Tool ◽  
Department Of Energy ◽  
Two Stage ◽  
Heat Exchanger Design ◽  
Clothes Dryer ◽  
Vapor Injection ◽  
Injection Cycle

An energy efficient two-stage heat pump clothes dryer (HPCD) was successfully developed. This new dryer utilizes three advanced technologies: vapor injection cycle, compact heat exchanger and brushless direct current (BLDC) fan motor. An in-house heat exchanger design tool – CoilDesigner was utilized to design and optimize the evaporator and condenser in the vapor injection cycle. One electric clothes dryer (CD) from U.S. market was selected as the baseline product, and one hybrid HPCD from European market was selected as the best state-of-the-art commercial product in terms of energy efficiency. These two commercial products and the constructed two-stage HPCD prototype were tested according to the Department of Energy (DOE) dryer test standards. Experimental evaluation revealed that the two-stage HPCD achieved 59% energy savings and improved energy factor (EF) by 143% as compared to the electric dryer. It also achieved 25% energy savings and improved EF by 33% as compared to the hybrid HPCD. This implied that the two-stage HPCD could save energy up to 42 TW·h annually if this technology is fully deployed to replace all U.S. electric CDs. Cost analysis indicates that the payback period of the two-stage HPCD is only 2.2 years as compared to the electric dryer with bottom cabinet. Therefore, the two-stage HPCD is an economically competitive greener option.

scholarly journals Energy, Exergy, and Environmental (3E) Analysis of Hydrocarbons as Low GWP Alternatives to R134a in Vapor Compression Refrigeration Configurations

2021 ◽  
Vol 11 (13) ◽  
pp. 6226
Author(s):  
Morteza Ghanbarpour ◽  
Adrián Mota-Babiloni ◽  
Bassam E. Badran ◽  
Rahmatollah Khodabandeh
Keyword(s):  
Heat Exchanger ◽  
Environmental Impact ◽  
Impact Analysis ◽  
Internal Heat ◽  
Refrigeration Cycle ◽  
Vapor Compression ◽  
Two Stage ◽  
Internal Heat Exchanger ◽  
Vapor Injection ◽  
Flash Tank

The phase-down of hydrofluorocarbons and substitution with low global warming potential values are consequences of the awareness about the environmental impacts of greenhouse gases. This theoretical study evaluated the energy and exergy performances and the environmental impact of three vapor compression system configurations operating with the hydrocarbons R290, R600a, and R1270 as alternatives to R134a. The refrigeration cycle configurations investigated in this study include a single-stage cycle, a cycle equipped with an internal heat exchanger, and a two-stage cycle with vapor injection. According to the results, the alternative hydrocarbon refrigerants could provide comparable system performance to R134a. The analysis results also revealed that using an internal heat exchanger or a flash tank vapor injection could improve the system’s efficiency while decreasing the heating capacity. The most efficient configuration was the two-stage refrigeration cycle with vapor injection, as revealed by the exergy analysis. The environmental impact analysis indicated that the utilization of environmentally-friendly refrigerants and improving the refrigeration system’s efficiency could mitigate equivalent CO2 emissions significantly. The utilization of hydrocarbons reduced the carbon footprint by 50%, while a 1% to 8% reduction could be achieved using the internal heat exchanger and flash tank vapor injection.

scholarly journals Experimental Study on the Cycle Performance Characteristics of the CO2 Heat Pump System under the Cooling Condition

2017 ◽  
Author(s):  
Hee Jeong Kang ◽  
Zhen Huan Wang ◽  
Jun Son ◽  
Sun-Joon Byun ◽  
Young-Chul Kwon
Keyword(s):  
Heat Exchanger ◽  
Heat Pump ◽  
Internal Heat ◽  
Optimal Operation ◽  
Performance Characteristics ◽  
Cycle Performance ◽  
Pump System ◽  
Heat Pump System ◽  
Operation Conditions ◽  
Internal Heat Exchanger

Developing high performance HVAC system using natural refrigerants including carbon dioxide (CO2) has been important in respect of environmental preservation and associated technologies. Thus studies to optimize the HVAC (heating ventilation air conditioner) system using natural refrigerants through clarifying the cycle performance characteristics are necessary. The CO2 heat pump system using air and water sources was consisted to examine its performance characteristics, and by varying conditions of several factors that affect or characterize the system performance like the amount of refrigerant charge, EEV (electronic expansion valve) opening, and internal heat exchanger under cooling mode. The performance characteristics of CO2 heat pump system were tested by using an air enthalpy calorimeter. In the case of the CO2 heat pump system without internal heat exchanger, the opening of #3 EEV and #4 EEV was 60% and refrigerant charge amount was 5,600g. However, in the case of that with internal heat exchanger, the best performance was obtained when the opening of #2 EEV is 20%. From the present studies, it was observed that the performance variation and operational characteristics of the CO2 heat pump system were affected by design factors like refrigerant charge amount, EEV opening, and internal heat exchanger and thereby, the configuration on an optimal operation conditions of the system was enabled.

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