How to Select Suitable BITZER Compressor Units for Fruit Cold Storage 2

III. Five Core Parameters to Be Calculated During Model Selection

1. Accurate calculation of refrigeration load, avoid rough estimation only by volume

Reference standard: For temperate fruit fresh-keeping warehouses at about 0℃ with standard thermal insulation, the unit volume load is 110～150W/m³; the load of high-temperature fresh-keeping warehouses for tropical fruits is 90～120W/m³.

Additional load factors: Frequent door opening, daily mass incoming fresh fruit requiring pre-cooling, poor thermal insulation of warehouse envelope and high ambient temperature in summer. The cooling capacity shall be increased by 15%～25% as margin to prevent insufficient cooling in hot summer.

2. Distinguish air-cooled and water-cooled condensation modes

In regions south of the Yangtze River with high ambient temperature in summer (Shanghai, Jiangsu, Zhejiang, South China), air-cooled units have higher condensing temperature, so one higher capacity grade is recommended during selection. Water-cooled units deliver higher energy efficiency if water supply is available, saving power consumption in long-term operation.

3. Match refrigerants with compressor models

For new projects, models compatible with R404A and R507A are preferred. For renovation projects, confirm the original refrigerant; random replacement is prohibited to avoid mismatched compressor lubrication.

4. Capacity regulation function is essential

There is a huge temperature difference between no-load and full-load operation of fruit cold storage. Models equipped with capacity regulation are prioritized to avoid frequent start-stop of compressors. Multi-unit parallel scheme can be adopted for small cold storage to adjust load by unit start-stop.

5. Set aside margin for environmental conditions

The extreme ambient temperature can reach 38～42℃ in southern China. Model selection must check cooling capacity under extreme high-temperature working conditions instead of average temperature, preventing failure to lower warehouse temperature in summer and subsequent fruit rot.

IV. Common Pitfalls to Avoid in Model Selection for Fruit Cold Storage

1. Do not blindly select low-temperature models

Many purchasers directly adopt freezer models for tropical fruit storage. Excessive compression ratio leads to high exhaust temperature, surging energy consumption and long-term inefficient operation with significantly increased failure rate. High-temperature dedicated models matching high-temperature fresh-keeping working conditions are the optimal solution for tropical fruits.

2. Avoid insufficient margin of compressor capacity

Fresh fruits bring a large amount of field heat when put into storage. Insufficient cooling capacity will lead to slow temperature reduction. Continuous fruit respiration accelerates ripening and rot, resulting in direct economic losses.

3. Attach importance to supporting systems; compressor alone does not represent a complete solution

After selecting the BITZER compressor host, condensers, air coolers, expansion valves and oil separators must match the working conditions of the compressor. High-power units are recommended to be equipped with high-efficiency oil separators to ensure lubrication and extend compressor service life.

4. Parallel schemes are preferred for long-term storage warehouses

Compared with single units, multiple parallel units can operate alternately. Maintenance will not shut down the whole warehouse, ensuring constant-temperature storage of fruits and reducing shutdown risks.

V. Conclusion

The selection of BITZER compressor units for fruit cold storage follows this logic: Confirm fruit varieties to be stored → Determine designed storage temperature and evaporation temperature → Calculate actual refrigeration load → Select piston or screw models according to cold storage scale → Verify cooling capacity under extreme high-temperature conditions and supporting systems. Small turnover cold storage at producing areas is preferably equipped with BITZER semi-hermetic piston condensing units; large fruit warehousing and controlled atmosphere fresh-keeping warehouses above thousands of cubic meters recommend screw parallel units. Scientific matching of working conditions can give full play to the advantages of stable and durable BITZER compressors, accurately guarantee the fresh-keeping cycle of fruits, realize energy-saving operation, and reduce fruit loss and power costs.