Microprocessor-based monitoring system for ammonia absorption chiller utilizing waste energy

An inexpensive monitoring method for an ammonia-absorption refrigeration system utilizing waste heat energy was developed. The device provides quantitative information on the cooling energy produced and the flow rate to evaluate energy savings, as well as the values of seven temperatures and four pressures for system performance evaluation. A BTUSA 682-RH BTU meter with a TR 400 flow meter was used to measure the BTUs and flow rate. Type K thermocouples convert the required temperatures into analog voltage signals. Pressures are converted to analog voltage signals by OMEGA PX 94 absolute pressure transducers. These analog voltages are input to an 8-b A/D converter. The values of BTUs, flow rate, temperatures, and pressures are input and stored in an MC68000-based microcomputer. This information can be transferred to a remote personal computer or terminal by RS-232 communications to be monitored, stored, displayed, and/or analyzed