TY - JOUR
T1 - Design-oriented modelling on cooling performance of the earth-air heat exchanger for livestock housing
AU - Wang, Xiaoshuai
AU - Bjerg, Bjarne Schmidt
AU - Zhang, Guoqiang
PY - 2018/9/1
Y1 - 2018/9/1
N2 - Access to inexpensive cooling sources is a precondition for developing cost-effective methods to mitigate heat stress among farm animal under hot climate conditions. The earth-air heat exchanger (EAHE) is a promising energy-effective technique that can be used to reduce the cooling load of a livestock building in hot days. Several studies have been carried out to assess the feasibility of EAHE for tempering air in livestock buildings. However, no mathematical model serving for EAHE design for livestock buildings has been developed, in which the EAHE system is often operated continuously to keep animals comfortable and productive. This work firstly deduced a regression model for predicting the air temperature difference between an EAHE tube inlet and outlet (ΔTi-o) using response surface methodology (RSM) based on the data obtained from validated steady-state numerical simulations. Four key design and operation factors (tube diameter, tube length, air velocity, and the temperature difference between inlet air and the undisturbed soil) were incorporated into the model. Based on the regression model, a mathematical model for predicting the cooling capacity (CC) of an EAHE tube was obtained. Parametric analysis was conducted to reveal the effects of the four factors on both the ΔTi-o and the CC. The models on cooling performance allow the designers to optimize the EAHE configuration for cooling livestock buildings.
AB - Access to inexpensive cooling sources is a precondition for developing cost-effective methods to mitigate heat stress among farm animal under hot climate conditions. The earth-air heat exchanger (EAHE) is a promising energy-effective technique that can be used to reduce the cooling load of a livestock building in hot days. Several studies have been carried out to assess the feasibility of EAHE for tempering air in livestock buildings. However, no mathematical model serving for EAHE design for livestock buildings has been developed, in which the EAHE system is often operated continuously to keep animals comfortable and productive. This work firstly deduced a regression model for predicting the air temperature difference between an EAHE tube inlet and outlet (ΔTi-o) using response surface methodology (RSM) based on the data obtained from validated steady-state numerical simulations. Four key design and operation factors (tube diameter, tube length, air velocity, and the temperature difference between inlet air and the undisturbed soil) were incorporated into the model. Based on the regression model, a mathematical model for predicting the cooling capacity (CC) of an EAHE tube was obtained. Parametric analysis was conducted to reveal the effects of the four factors on both the ΔTi-o and the CC. The models on cooling performance allow the designers to optimize the EAHE configuration for cooling livestock buildings.
KW - Earth-air heat exchanger
KW - Livestock housing
KW - Mathematical model
KW - Numerical simulation
KW - Parametric analysis
U2 - 10.1016/j.compag.2018.07.006
DO - 10.1016/j.compag.2018.07.006
M3 - Journal article
AN - SCOPUS:85049482447
SN - 0168-1699
VL - 152
SP - 51
EP - 58
JO - Computers and Electronics in Agriculture
JF - Computers and Electronics in Agriculture
ER -