23 September 2011

DYNAMIC MODELING OF AN AIR SOURCE HEAT PUMP WATER HEATER


This paper presents a dynamic simulation model to predict the performance of an
air source heat pump water heater (ASHPWH). The mathematical model consists of
submodels of the basic system components i.e. evaporator, condenser, compressor, and
expansion valve. These submodels were built based on fundamental principles of heat
transfer, thermodynamics, fluid mechanics, empirical relationships and manufacturer’s data
as necessary. The model simulation was carried out using MATLAB software. Refrigerant
R134a with two different reservoir volumes 150L & 200L are investigated. Additionally,
different ambient air temperatures are considered. Results show that the rate of hot water
production increases as the water reservoir volume decreases and the integrated COP
increases as the ambient temperature increases.