Experimental analysis on the decoupling of temperature and humidity by using a double circuit cooling coil

Abstract

Double circuit cooling coil (DCCC) can be used to control the indoor air conditions in built environments. The working principle of DCCC is to adjust the chilled water flow rate and chilled water temperature in a cooling coil independently. The objective of this work is to obtain the quantitative influence of the variation of the chilled water flow rate and chilled water temperature on the outlet process air conditions, and the relationship between moisture removal capacity (MRC) and sensible heat ratio (SHR). A test air conditioning system is built to analyze the performance of the DCCC and case studies are carried out under various operating conditions. The response surface methodology coupled with a Box–Behnken design is conducted to fit the empirical regression models that are used to predict the outlet air process temperature and humidity in the DCCC system. The results show that independent control of outlet process air can be achieved if the outlet air temperature is controlled by the chilled water flow rate and the outlet air humidity is controlled by the chilled water temperature. The increase of MRC is inversely proportional to the increase of SHR.