To determine whether the refrigeration effect of the chiller is normal, the core is to check whether the temperature meets the standard, the parameters are stable, and there are no abnormalities in operation. Three key indicators and practical inspections can be used to quickly determine:
Temperature difference between outlet and return water: Under normal operating conditions, it should be 5-7 ℃ (if the outlet water temperature is set to 7 ℃ and the return water temperature is about 12-14 ℃). A small temperature difference may result in a decrease in heat transfer efficiency, while a large temperature difference may result in excessive load or insufficient flow.
Deviation between actual temperature and set value: After stable operation, the outlet temperature should differ from the set value by ± 1-2 ℃ (± 0.1-0.5 ℃ for precision models). If the deviation exceeds the range, the refrigeration effect will be abnormal.
Environmental adaptability: In high temperature environments (such as above 35 ℃ in summer) or at full load, the equipment should be able to maintain the set temperature without continuous heating or frequent shutdown protection.
High and low pressure: within the range indicated on the equipment nameplate (such as R134a refrigerant, low pressure of about 0.3-0.5MPa, high pressure of about 1.2-1.8MPa). If the pressure is too high, it may be due to poor heat dissipation, and if it is too low, it may be due to refrigerant leakage.
Water circulation flow rate: The flow meter reading is stable and does not show a significant decrease. If the flow rate decreases, it may be due to pipeline blockage or water pump failure, indirectly leading to a decrease in refrigeration efficiency.
Running sound and vibration: The compressor, water pump, and fan have no abnormal noise (such as metal friction sound, high-frequency whistling), small vibration amplitude, and no severe shaking.
Start stop frequency: Under normal circumstances, it should operate stably without frequent start stop (more than 3 times within 1 hour). Frequent start stop may be due to mismatched cooling capacity or control system failure.
Energy consumption changes: Under the same load, the energy consumption has significantly increased compared to previous periods, which may be due to a decrease in heat exchange efficiency (such as scaling) leading to a deterioration in refrigeration efficiency and forcing equipment to operate at high loads.
Record the set temperature and the actual outlet/return water temperature, and calculate whether the temperature difference is within the range of 5-7 ℃.
Check the pressure gauge to confirm if the high and low pressures are within the normal range indicated on the equipment.
Observe whether there is frost on the pipeline (except for the evaporator). If there is frost on the pipeline, it may be due to insufficient refrigerant or a malfunction of the throttling component.
Listen to the sound of the device running, feel the vibration, and if there are no abnormalities, it can be preliminarily determined that the refrigeration cycle is normal.