When choosing a chiller, multiple factors such as application scenarios, performance parameters, environmental conditions, cost-effectiveness and long-term maintenance should be comprehensively considered to ensure the efficient, stable and economical operation of the equipment. The following is the specific analysis:
I. Application Scenarios and Load Requirements
Load type and scale
Low-temperature scenarios (such as below -40℃) : Cascade or two-stage compression refrigeration units should be selected.
Precision temperature control (such as in semiconductor manufacturing) : It is necessary to be equipped with PID control + electronic expansion valve, and the temperature fluctuation should be controlled within ±0.1℃.
Heat generation calculation: Based on the equipment power, operating time and environmental heat dissipation, accurately calculate the total cooling demand. For instance, when cooling a 100kW heat-generating device, a redundancy of 15% to 20% should be reserved and a unit with a cooling capacity of 120kW should be selected.
Load fluctuation: In scenarios such as data centers and industrial production lines, the load fluctuates greatly. It is necessary to select units with high partial load energy efficiency (such as magnetic levitation centrifugal types, with an IPLV of over 14).
Special process requirements
Terminal equipment matching
Chilled water flow and temperature difference: Select the matching evaporator based on the flow and temperature difference requirements of the terminal equipment (such as air conditioning units, cold air fans). For instance, if a temperature difference of 5℃ and a flow rate of 20m³/h are required at the end, the evaporator must meet these parameters.
Water system resistance: If the resistance of the terminal equipment is relatively large, an evaporator with a small pressure drop should be selected or a booster pump should be added.
Ii. Environmental Adaptability
Climatic conditions
High-temperature areas: Select high-temperature resistant compressors (such as maintaining 95% cooling capacity in a 45℃ environment) and high-efficiency condensers;
In low-temperature areas: The EPC (Economizer Cycle) technology is adopted to extend the natural cooling time. For instance, in the Harbin area, an annual energy saving of 2,489 hours is achieved.
Corrosive environments: Anti-corrosion coated units or stainless steel heat exchangers should be selected in coastal or chemical industrial areas.
Space and installation conditions
Air-cooled units: Reserve space for air intake and exhaust to prevent hot air backflow. The modular design allows for stackable installation, saving floor space.
Water-cooled units: They need to be equipped with cooling towers and water pumps, suitable for large buildings or industrial parks.
Noise control: In scenarios such as hospitals and schools, low-noise units should be selected (for example, the noise of the scroll type is less than 70dB).
Iii. Reliability and Maintenance Convenience
Reliability of key components
Compressor: Choose brand compressors (such as Bitzer, Copeland), with a failure rate of less than 0.5% per year.
Control system: Equipped with fault diagnosis and remote monitoring functions, for instance, the Xinran unit supports real-time viewing of the operating status via a mobile phone APP.
Maintenance cycle and difficulty
Lubricating oil change: Traditional units require oil change every 2,000 to 3,000 hours, while magnetic levitation units do not need oil change.
Condenser cleaning: Clean once a year when the water quality is poor. Reserve cleaning interfaces and drainage channels.
Spare parts supply: Choose a brand with a well-established local service network to shorten maintenance time.
Green and low-carbon technology
Waste heat recovery: For instance, Tencent's Tianjin data center utilizes magnetic levitation heat pumps to recover the waste heat of chilled water (COP 4.9) for office heating, reducing carbon emissions by 4,040 tons annually.
Natural cooling: In low-temperature seasons, external cold sources are utilized to reduce the operating time of the compressor, and the PUE pressure can be reduced to below 1.2.
Iv. Selection and Decision-making Process
Demand research: Clarify load scale, temperature accuracy, environmental conditions, etc.
Preliminary screening: Narrow down the range based on cooling capacity and energy efficiency grade;
Technical comparison: Evaluation of partial load performance, noise, maintenance costs, etc.
Economic analysis: Calculate LCC and payback period of investment;
On-site inspection: Visit the operation cases of similar projects to verify the stability of the equipment;
Final decision: Determine the model by comprehensively considering technical, economic and policy factors.
