Experimental and Simulation Studies of a Rock Solar Heat Storage in a Livestock Building

Abstract

ABSTRACT AMONG various solar collection systems, air-type col-lectors are becoming practical in livestock buildings. The popularity of air-type collectors is mainly due to their simplicity, low initial and operating costs. Com-monly, air-type collectors are sized to preheat the minimum ventilating air requirements (MWPS-22, 1980). A heat storage medium such as rock is recom-mended in conjunction with the collector in order to enhance the full usage of the collected heat. Recir-culating the ventilating air from the house into the solar collector and charging/discharging a storage as practic-ed elsewhere is not practical in animal shelters. The amount of contaminants such as dust, noxious gases and biological organisms are much higher in an animal en-vironment than in human housing or in greenhouses. Therefore, in livestock shelters, the fresh ventilating air passed through the collector is continuously flowing in a single direction through the storage. A temperature wave front is formed in the rock which causes a phase shift between input and output temepratures. An ideally designed storage shifts the warm output temperatures to the daily coldest periods. These cold periods normally oc-cur at night. It is illustrated in Fig. 1, that a 12 h shift in output temperatures will result in substantial energy sav-ings. In this paper the results of experimenting with a solar collector/rock storage in a turkey building are explained. A simulation model with which rock and air temperature can be predicted, was used to analyse the design variables or a rock heat storage.