In order to develop an intelligent gas-fired absorption water chiller-heater, we have developed two types of controllers using microcomputers. The first type of controller has three functions. It controls operation to increase part-load efficiency by regulating the circulating flow rate of weak solution and also to reduce auxiliary equipment power by cutting the diluting operation time required after shut-down. These two functions result in significant energy savings. By indicating the contamination status of the cooling water tube, the controller can predict and thus prevent failure. The second type of controller has a telecommunications function, in that it monitors and records the operational status of the chiller-heater, not only on the machine side, but also at a remote site. This allows a number of chiller-heaters to be monitored from one monitoring center, thus saving labor and facilitating maintenance. These sophisticated new controllers reduce costs by increasing energy efficiency and simplifying
management.

Units: SI