1. 제 목 : EVALUATION OF CARBON DIOXIDE AS R22 SUBSTITUTE FOR


RESIDENTIAL AIR-CONDITIONING





2. 연 사 : Piotr A. Domanski, Ph.D.


(Leader, Thermal Machinery Group, NIST, U.S.A.)





3. 일 시 : 2002년 9월 13일 (금) 11:00-12:00





4. 장 소 : 301동 1512호





5. 요 약 :


Each refrigerant possesses unique thermodynamic and transport properties that affect it’s performance in a refrigeration or air-conditioning system. Because of complex issues related to component design and system optimization, a fair evaluation of different refrigerants offers a considerable difficulty, the level of which increases with the disparity of properties of the studied refrigerants. This problem pertains to both laboratory evaluations and evaluations using a simulation model, and is evident when performance of traditional refrigerants and high-pressure carbon dioxide are compared.


This talk will cover a simulation study in which we compared R22 and carbon dioxide in residential comfort cooling. We used semi-theoretical simulation models, which account for different thermodynamic and transport properties of the refrigerants and allow one to represent different refrigerant circuitry arrangements in the heat exchangers. When equivalent heat exchangers were used in both systems, the CO2 system had a significantly inferior coefficient of performance than the R22 system. The entropy generation analysis showed that the CO2 evaporator operated with less irreversibilities than the R22 evaporator; however, the CO2 gas cooler and expansion device generated more entropy than their R22 counterparts and were mainly responsible for the low COP of the CO2 system. Simulations trade-offs that could have influenced simulation results will be discussed.


 





6. 연사약력 :


Technical University of Gdansk (Poland), M.S.,Mechanical Engineering,1972


Catholic University of America, Ph.D., Mechanical Engineering, 1982


Bronze Medal Award from the Department of Commerce, 1992


NIST’s William P. Slichter Award, 1995





7. 문 의 : 기계항공공학부 김민수 교수 (880-8362)