ISHS Acta Horticulturae 399: Greenhouse Environment Control and Automation
EXPERIMENT OF HEAT RECOVERY FROM COMPOST BY A TRIAL HEAT EXCHANGER |
| Authors: | H. Seki, T. Komori |
| Keywords: | compost, alternative energy, heat recovery, greenhouse, exergy |
| Abstract:
In order to clarify the possibility of using the heat generated in composting as an alternative energy source for heating greenhouses, experiment of heat recovery from compost by a trial heat exchanger is conducted. Heat is recovered both by a flexible pipe set along the side wall of a cylindrical compost container and by a condenser-type heat exchanger installed above the container. Air is passing through the flexible pipe and heat exchanger as a medium fluid of heat transfer. According to the experimental results, the quantity of heat recovered is 1.2–2.6x105 kJ in 7–14 days, which is 16–22% of the whole amount of heat generated in composting. On the other hand, the quantity of exergy recovered is 3.0–9.3x103 kJ in the same period, which is about 50% of the total input power required to let medium fluid flow into the flexible pipe and heat exchanger and for aeration of a compost bed. The reason why the amount of exergy recovered is less than the total input power is that the thermal insulation of the experiment is poor and the pressure drop in passing the medium fluid through the heat exchanger is large. However, the pressure drop can be easily reduced by replacing the tubes for heat exchange in the heat exchanger to those of larger diameter, and then the amount of exergy recovered will become larger than the total input power. | |
Download Adobe Acrobat Reader (free software to read PDF files) | |
