배기가스용 고온재생기의 성능특성에 대한 실험적 연구

Abstract

Recently, the ozonosphere depletion and greenhouse effect was caused by heat pump system using the CFC and HCFs refrigerant and it have become more and more serious. Therefore, usage of existing refrigerant has regulated through the International agreement. The absorption chiller-heater using just the natural refrigerants has very little effects on the environmental pollution. The absorption chiller-heater is received the heat from the low temperature using the high-temperature heat source and emits the heat to the middle temperature state. As the cooling uses natural gas in summer, peak lode can be relieved and the energy supply and demand may doesn't care the capacity of the seasonal limitation. Cogeneration has been generalized in order to utilize an efficient application of the energy. The efficiency of cogeneration or micro-gas turbine is extremely low level about 20~30%. The engine exhaust gas temperature is about 500oC. When engine exhaust gas is used to the absorption chiller-heater, energy efficiency can be increased up to 75~90% and the coefficient of absorption chiller-heater performance can be improved significantly. In the absorption chiller-heater, the high-temperature generator using exhaust gas is an important factor to achieve high system performance. To investigate performance of the high-temperature generator using exhaust gas in the absorption chiller-heater, Lab. scale high-temperature generator using exhaust gas was designed and setup. Since it is very difficult to uses and control the 500oC exhaust gas, the experiment was performed using 200oC air instead of 500oC exhaust gas by using the dimensionless scaling method. It is very important to investigate the performance change of high temperature regenerator using exhaust gas according to the inlet condition of the exhaust gas and absorbing solution. In this study, to analyse the performance of the high-temperature generator using exhaust gas in the absorption chiller-heater with operating conditions, the inlet condition of solution liquid and exhaust gas was changed. As a result, air mass flow rate ratio increased from 80% to 120% in the inlet concentration of high-temperature generator of 56% and 53%, heat capacity was increased by 30%, 37%, respectively. In absorption liquid mass flow rate ratio of 100%, as the mass flow rate ratio of absorption liquid was changed from 80% to 120%, heat capacity of high-temperature generator of inlet concentration of 56%, 55%, 54%, 53% was almost constant by 3.6%, 4.47%, 5.6%, 5.7%, respectively. Concentration difference of absorption liquid between the inlet and outlet is closely related to steam mass flow rate from separating of the absorbing solution. In air mass flow rate ratio of 100% and inlet concentration of absorption liquid of 55%, when array of fin-tube heat exchanger was changed from first to fourth, the decreasing rate of air side temperature was reduced by 17.7%, 5.8% 2.1%, 1.1%, respectively. However, as the array of fin-tube heat exchanger was changed from fifth to outlet, the decreasing rate of air side temperature was increased by 1.5%, 3%, respectively. As the air mass flow rate ratio was changed from 80% to 120%, for all inlet concentration of absorption liquid, the pressure drop of air side was increased by 72 kPa. Except for the variation of air mass flow rate ratio, the air side pressure drop was almost constant by the pressure of 107 kPa with the operating condition.