| Title |
Capacity Modulation of a Multi-Type Heat Pump System Using PID Control |
| Keywords |
Multi-type heat pump ; 멀티형 열펌프 ; Capacity modulation ; 용량조절 ; PID control ; PID 제어 ; Variable speed compressor ; 가변속 압축기 ; Electronic expansion valve ; 전자팽창 밸브 |
| Abstract |
Performance of a water-to-water multi-type heat pump system using R22 has been experimentally investigated. Total refrigerant flow rate was adjusted with a variable speed compressor and the refrigerant flow rate for two indoor units were controlled by electronic expansion valves. Evaporator outlet pressure of refrigerant and indoor unit outlet temperatures of secondary fluid were selected as controlled variables. Experiments were carried out for both cooling and heating modes using PID control method. Results show that the multi-type heat pump system can be adequately controlled by keeping control gains at certain levels for various operating conditions. |