Development of a water pipe network serving as a conductive cooling system applied to dairy farms

Abstract

Introduction: In desert climates, high temperatures can cause heat stress on dairy farms. Aviable alternative to this problem is to develop a network of water pipes connected to heat exchangers (HEs) that operate as a conductive cooling system. Objective: To propose a water supply system connected to a series of HEs, installed under bedding in a dairy barn freestall system, and analyze heat transfer along a large-scale water pipe network. Methodology: The EPANET water quality module was used to design the system. Temperature predictions were validated with experimental data from a network of four HE pipes installed under the bedding. A network was then designed to supply water to 1 000 HEs in order tocalculate the efficiency of the system for a real dairy farm. Results: Insulations with values of 0.095 and 0.0475 W∙m-1∙°C-1 increased the cooling capacity of water-carrying pipes by 7 and 12 %, respectively. Increasing the flow rates from 1 to 7 L∙min-1 increased the cooling capacity; however, the cooling efficiency decreased by at least 12 %. Study limitations: A validation was performed on a section of the pipe network and a simulation for the entire network. Originality:V EPANET was implemented for a mass and heat balance in a pipe network supplying water to HEs. Conclusion: The conductive cooling system is viable in areas with a desert climate and its efficiency depends on the level of thermal insulation and flow in the pipe network.