摘要 |
<p>First to third openings are formed stepwise in a rotor side wall portion of a flow control valve disposed in a hot water circuit. Third positions (a) and (b) are established between a first position in which a first communication passage for communication between inlet and outlet pipes of the flow control valve is fully closed and a second position in which the first communication passage is fully opened. A duty control is performed so that the rotor reciprocates repeatedly among the above four positions. In this way, in the flow control valve for controlling the amount of the fluid flowing in the fluid passage, the valve colliding noise, the water hammer noise, and the temperature variation in the heating heat exchanger can be reduced.</p> |