Recovery and utilization of compost heat from an enclosed vertical-type composting facility development of warmed...

This paper describes a compost heat utilization system that recovers the exhaust heat generated by an enclosed vertical-type composting facility (EVCF) installed in a dairy farm with 150 heads of dairy cows. The recovered exhaust heat warms the water supplied to dairy cows. This study determines the temperature of the supplied water and the heat utilization efficiency of the system. During operation, the EVCF generated a compost temperature of 60-70°C and an exhaust temperature of 60°C. The system provided warm (30°C) water throughout the day by raising the water temperature at night when the drinking water requirements were reduced and heat demand used for warming the water was low. Thermal energy generated 356% of the power consumption, and 49.3% of the generated energy was used for warming the water. The compost heat used to warm water was 2017 MJ d^-1 , which was equivalent to 68.7 L d^-1 of kerosene when the same amount of water was warmed in a boiler.