| 摘要 |
<p>PURPOSE:To perform continuous stable operation efficiently, by controlling the number of rotation of an engine in correspondence with a heating load, in a greenhouse heating apparatus, wherein warm water is forcibly circulated along an engine heat pump and radiators in the greenhouse. CONSTITUTION:A bypass flow path 18 is provided between a warm water feeding path 16, which is guided from an engine heat pump 3, and a returning flow path 17, which is introduced to the heat pump 3. Part of a specified quantity of warm water, which is sent out of the heat pump 3, is guided to the bypass flow path 18 through the connecting point of the warm water feeding path 16 and the bypass flow path 18. A solenoid valve mechanism 19, whose opening degree is freely regulated, is provided in order to regulate the flow rate. The valve mechanism 19 is connected to a control circuit 15, so that the flow rate in the bypass is controlled based on the detected result of a free-air temperature detecting sensor S1, which is provided in the vicinity of a greenhouse 1. The control is performed so that the flow rate in the bypass is reversibly increased as the free air temperature is increased.</p> |
