18 May 2017
In this paper, a study on geometric parameter of a wrap-around condenser for a water tank with 200 L capacity has been conducted using experimental and numerical methods. Numerical results are well validated by the experimental ones with a total time deviation less than 2% as the same volume of water was heated to 55 °C. For the wrap-around condenser copper coils with different structural parameters, the average COP (coefficient of performance) of air source heat pump water heater (ASHPWH) varies from 3.8 to 4.6 under the standard condition. Copper tubes with smaller diameter (i.e. 5mm and 7mm) were found to outperform these with larger diameter by improving the heat transfer efficiency and reducing initial copper costs. Moreover, it suggests a better heating performance of the copper coils wrapped around the bottom and lower part of the water tank. This study suggests that given the proper pipe parameters such as location, spacing and turns, a higher average COP of air source heat pump water heater can be achieved and the total heating time is decreased relatively.