摘要 |
On board ships there are cooling systems comprising a heat exchanger (1) operating as a central cooler, through which sea water is pumped by means of different pumps (2-5). Fresh water for cooling the main engine (21) of the ship, and devices (15-18) of various kinds on board the ship, is pumped through the heat exchanger (1) where it is cooled by the sea water. A by-pass conduit (11) extends between the heat exchanger inlet conduit (9) and outlet conduit (10) for fresh water, a three-way valve (12) being arranged to distribute the fresh water flow through the heat exchanger (1) and the by-pass conduit (11), respectively, depending on the momentary cooling demand of the main engine (21) of the ship and/or the devices (15-18). Thereby a predetermined temperature may be maintained in the fresh water circuit. Means are provided for sensing the flow through the heat exchanger (1), or the by-pass conduit (11), and in response thereto increasing or decreasing stepwise the pump capacity for pumping sea water through the heat exchanger (1). |