Maintaining and servicing chillers is crucial for ensuring efficient operation and extending their lifespan. While different types of chillers (such as air-cooled and water-cooled) may have slightly different maintenance details, the core principles remain the same. Below is a detailed maintenance and servicing guide:
 

I. Daily/Weekly Operational Checks
1. Monitoring Operating Status
Temperature and Pressure: Observe the high and low-pressure gauges and water temperature display on the control panel. Ensure that the high pressure is within 1.5-2.0 MPa (water-cooled) or 1.8-2.4 MPa (air-cooled), the low pressure is within 0.3-0.5 MPa, and the water temperature is maintained within ±1℃ of the set value. If the pressure is abnormal (such as excessively high high pressure or excessively low low pressure), it may be due to condenser clogging, refrigerant leakage, or compressor failure, and should be investigated promptly.
Current and Voltage: Check the operating current of the compressor and water pump using the electrical control cabinet instruments. It should be within 80%-110% of the rated value, and the voltage fluctuation should not exceed ±10% to avoid overload or voltage instability damaging electrical components.
Abnormal Sounds: If abnormal sounds such as compressor noise, excessive fan vibration, or water pump jamming occur during operation, stop the machine immediately and check. This may be due to loose parts, bearing wear, or foreign objects entering the system.
2. Key Component Inspection
Air-cooled: Check if the fan blades are dusty or deformed, and if there are any abnormal sounds during operation. Ensure smooth ventilation (no obstructions within 1 meter of the fan).
Water-cooled: Check if the cooling tower water distribution is even, if the filler is scaling, if there is abnormal vibration during the operation of the cooling water pump, and if there are any water leaks in the pipes (focus on checking flange and valve connections).
 

II. Regular Maintenance Items (Monthly/Quarterly)
1. Condenser and Evaporator Cleaning
Air-cooled Condenser: Use compressed air (pressure ≤0.6 MPa) or a soft brush to clean dust, fluff, and oil stains from the fin surface (a diluted neutral detergent can be used for rinsing; avoid using acidic or alkaline agents) to ensure heat dissipation efficiency. If the ambient dust is high, cleaning can be shortened to every 2 weeks.
Water-cooled Condenser: Open the end cap and use a special cleaning brush or high-pressure water gun to rinse the scale from the inner wall of the heat exchange tubes (scale is easily formed in poor water quality; chemical acid washing, such as citric acid solution at a concentration of 5%-10%, can be used in conjunction with rinsing with clean water afterwards). This should be done at least twice a year.
Evaporator: Check the evaporator copper tubes (or plate heat exchanger) for corrosion and scaling. If the water temperature drops slowly, it may be due to reduced heat exchange efficiency, requiring disassembly and cleaning or circulation treatment with a special cleaning agent.

2. Refrigerant and Lubricating Oil Management
Refrigerant Replenishment: Regularly observe the refrigerant status through the sight glass (normally transparent and bubble-free). If bubbles persist or the refrigeration capacity significantly decreases, the system pressure should be checked and refrigerant should be added (this should be done by a professional to avoid air or water contamination).
3. Electrical System Maintenance
Check the contactors and relays in the electrical control cabinet for oxidation and sticking, and check if the wiring terminals are loose (tighten with a screwdriver). Check the insulation layer of the wires for aging and replace damaged parts in a timely manner.
Test the sensitivity of various protection devices (such as high and low-pressure switches, overload protectors, and phase sequence protectors). Manually simulate fault conditions to check if automatic shutdown protection works.
 

III. Seasonal and Annual Maintenance (Semi-annual/Annual)
1. Special Treatment Before Seasonal Changes
Winter Shutdown: If a water-cooled chiller is to be shut down for an extended period, drain the accumulated water from the cooling tower, condenser, water pump, and pipes (antifreeze can be added) to prevent freezing and cracking. For air-cooled chillers, if the ambient temperature is below 0℃, it is recommended to cut off the power and cover with a dust cover to prevent the electrical components from getting damp.
Summer Startup: Before use, thoroughly inspect the heat dissipation system (such as cleaning the air-cooled condenser and replacing the cooling tower filler), test the startup performance of the fan and water pump, and replenish refrigerant or lubricating oil.
2. Annual In-depth Maintenance
System Leak Detection: Use a halide leak detector or soapy water to check pipe joints, valves, and welds for refrigerant leaks. If leaks are found, they should be repaired by welding, then vacuumized (vacuum degree ≤ -0.1 MPa) before refilling the refrigerant.
Water Treatment (Water-cooled): Check the pH value of the cooling water (preferably 6.5-8.5) and hardness (calcium and magnesium ion content ≤ 200 mg/L). If it exceeds the standard, add water stabilizers (such as corrosion inhibitors and scale inhibitors) or replace the circulating water to prevent scaling and corrosion of the equipment.
Compressor Performance Test: Measure the compressor's exhaust temperature and motor winding insulation resistance (≥2 MΩ). If performance decreases (such as insufficient exhaust pressure), the valve plates, piston rings, and other parts need to be disassembled and repaired.
 

IV. Special Maintenance Points for Different Types of Chillers
Air-cooled: Focus on the heat dissipation efficiency of the fan and avoid long-term operation in high-temperature, high-dust environments (ambient temperature should be ≤40℃).
Water-cooled: Strictly manage the circulating water quality, regularly clean the cooling tower (to prevent algae growth), and be sure to drain the water from the water system in winter.