In plate heat exchanger we have Four points: Hot side inlet, cold side inlet, hot side outlet and cold side outlet. can any one explain which one of those points considered as a supply from district cooling plant and its return? also which one is the supply point for the FCU/AHU and the return?Thanks
Cold side inlet, and cold side outlet.
Heat is exchanged between to liquids in the heat exchanger be that plate, shell and tube or other. If an air handler or FCU is cooling, it will have a cold water (liquid) inlet, and a warm water return to the heat exchanger. An evaporative condensing unit, chiller, or compression cycle cooler will send cold water to the heat exchanger to remove heat and accept the warm return for re-cooling. In this case to liquids are used because in the case of absorption cycle, the water is brine (Lithium Bromide) which is corrosive to AHUs. If the air handler is heating, it will accept hot water and return something cooler. Water is again separate because boiler saline (treated boiler feed water) might be either treated with alkali, or restricted to a fixed lesser volume. Heat exchanger normally use counter flow so that when cooling the The maximum temperature difference occurs first. The identification of piping is otherwise entirely logical.
