Heat Exchanger & Domestic Hot Water Storage Tank - In the front is a commercial heat exchanger. Behind the commercial heat exchanger is a domestic hot water storage tank.
The entire system is monitored by direct digital controllers to control the water temperature, the boilers, the valve actuators, and the heat exchangers. It is important to monitor the temperature of any domestic water system. Temperatures above 130° F. should be avoided as they will scald people. This can result in legal issues so it is important this is controlled accurately. Direct Digital Control can offers alarms for this issue in case something goes wrong or something fails.
Heat Exchanger & Domestic Hot Water Storage Tank
The supply water from the city is directed through the heat exchanger where it is heated to a set point temperature. This is usually 120 to 130 degrees Fahrenheit. 180-degree water from the boilers runs through tubes inside the heat exchanger while the cold water runs through the inside of the heat exchanger in separate channels outside the tubes where the hot boiler water is. The water is heated and then delivered to the community where it used for showers and washing dishes and other hot water uses.
Before the city water supply enters the heat exchanger the city water supply is diverted through a commercial hot water boiler economizer so that the colder city water supply is preheated to a temperature greater than 55 degrees F. which are the city water temperature supplied from the city water source. The economizer or preheater uses boiler flue gases to preheat the domestic water supplied to the heat exchanger for heating to comfortable temperatures. The heat exchanger is a shell and tube exchanger where 180-degree boiler water runs through some tubes in the exchanger while the city supply water enters another pipe near the boiler water pipe.
A heat exchange process takes place and the cool city water is heated to a higher temperature warm enough to take a bath but not too warm to be scalding. After water makes its journey through all that it is stored in the domestic hot water storage tank you see behind the heat exchanger.
Heat Exchanger & Domestic Hot Water Storage Tank