Potential Coefficient of Performance Improvements due to Glide Matching With R-407C

Published

July 1, 1998

Author(s)

M E. Marques, Piotr A. Domanski

Abstract

Potential improvements of the Coefficient of Performance (COP) were investigated for R-407C at cooling and heating conditions of a residential heat pump. The study used CYCLE-11, a semi-theoretical vapor-compression cycle model, which was upgraded to simulate cross-flow, counter-flow, and parallel-flow evaporator and condenser with no restrictions on specifying superheated vapor and subcooled liquid regions. The COP benefit of using counter-flow heat exchangers in a low-lift air-conditioning application was found to be 7.1% when compared to a system with a cross-flow evaporator and condenser. For heating conditions (high-lift application), the predicted benefit was 3.6%. These results are representative of a water-to-water system, where counter-flow heat exchangers are suitable for implementing glide matching. Since air-to-refrigerant heat exchangers are not counter flow but rather cross-counter flow (in the best case), the potential to improve COP in a practical air conditioner is lower. The COP penalty caused by glide mismatch (parallel flow) is approximately twice as severe as the benefit that can be realized from glide matching.

Proceedings Title

7th Proceedings of the International Refrigeration Conference at Purdue

Conference Dates

July 14-17, 1998

Conference Title

International Refrigeration Conference

Pub Type

Conferences

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Keywords

air conditioner, alternative refrigerants, coefficient of performance, glide matching, heat pump, refrigerants, thermodynamics, zeotropic mixtures

Citation

Marques, M. and Domanski, P. (1998), Potential Coefficient of Performance Improvements due to Glide Matching With R-407C, 7th Proceedings of the International Refrigeration Conference at Purdue, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=860757 (Accessed April 20, 2024)