| 摘要 |
<p>PURPOSE: A cooling-and-heating system is provided to improve the performance of heat transmission during a short time and the average performance of heat transmission. CONSTITUTION: A cooling-and-heating system comprises a compressor, a condenser, an expansion device (40), and an evaporator. The expansion device includes a first expansion valve (42) and a second expansion valve (44). The first expansion valve, which is a variable valve, generates a disturbance to a flow of a coolant by changing a flow rate of the coolant according to a periodic change of the opened extent of the first expansion valve. The second expansion valve is a maintenance valve in which a flow rate of the coolant passing through the second expansion valve is regular and the preset opened extent of the second expansion valve is regularly maintained.</p> |
