• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.19 no.6
• /
• pp.73-77
• /
• 2019

In this paper, the heat pump system was designed using heat absorption of the refrigerant or condensation heat. The cooperation system has been developed to pass a heat source of low temperature to a high temperature or to pass the heat source of high temperature to a low temperature. Heat pump for using the valve as a function of switching a condenser and an evaporator in a refrigerating cycle. As a result, heat pump system was developed by air source method. Therefore cooperating system for energy saving to solve at the same time as the cooling and heating by system of one was equipped.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.18 no.2
• /
• pp.719-725
• /
• 2017

Frozen milk products are commonly made in small refrigeration machines. R-502 has long been used as a refrigerant for soft ice cream machines, but it is being replaced with R-404A due to the issue of ozone layer depletion. However, R-404A has high global warming potential, so it also needs to be replaced. In this study, a mixture of R-290 and R-32 was considered as a new refrigerant. An optimization and performance evaluation of the mixture were conducted for a freezer volume of 2.8 liters. The focus of the optimization was the appropriate refrigerant charge and the opening of the expansion valve. At the optimized conditions, ice cream was produced in 6 minutes and 24 seconds with the mixture, and the COP was 0.83. For R-404A, the ice cream production time was 6 minutes and 22 seconds, and the COP was 0.90. The results may be used for the design of food refrigeration machines and to optimize other refrigeration cycles.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.22 no.7
• /
• pp.57-62
• /
• 2014

This study presented the feasibility of a coolant heat-source heat pump system as an alternative heating system for electrically driven vehicles. Heat pumps are among the most environmentally friendly and efficient heating technologies in residential buildings. In various countries, electric mobiles devices such as EV, PHEV, and FCEV, have been mainly concerned with heat pumps for new mobile markets. The experiments herein were conducted for various ambient temperatures and coolant temperatures to reflect the winter season. The system, a coolant heat-source heat pump, consisted of an inside heat exchanger, an outside heat exchanger, a motor driven compressor, an electronic expansion valve, and plumbing parts. For the experimental results, the maximum heating capacity and air discharge temperature are up to 6.3 kW and $62^{\circ}C$ respectively at an ambient temperature of $10^{\circ}C$, and coolant at $10^{\circ}C$. However, at $-20^{\circ}C$ ambient temperature and $-10^{\circ}C$ coolant temperature, conditions were insufficient to warm the cabin as the air discharge temperature was $13^{\circ}C$.