The air volume regulation of the condenser of low temperature chiller has a significant impact on the improvement of seasonal energy efficiency. By reasonably adjusting the air volume of the condenser, the condensing pressure can be optimized, thereby enhancing the refrigeration efficiency and energy efficiency ratio (EER) or seasonal energy efficiency ratio (SEER) of the system. The following will conduct a detailed analysis of the impact of condenser air volume regulation on seasonal energy efficiency from multiple perspectives.

The influence of condenser air volume regulation on condensing pressure

The air volume adjustment of the condenser directly affects the condensing pressure. In summer, the condensing pressure is usually high, which increases the power consumption of the compressor, reduces the cooling capacity, and thus affects the overall performance of the system. By adjusting the air volume of the condenser, the condensing pressure can be reduced, thereby reducing the load on the compressor and improving the refrigeration efficiency.

For instance, it is mentioned that precise control of the condensing pressure can be achieved by adjusting the rotational speed of the condensing fan or using a frequency converter. It is also pointed out that by adjusting the flow rate of cooling water or the air volume of the cooling tower, the condensing pressure can be effectively controlled, thereby optimizing the operational performance of the system.

2. The influence of condenser air volume regulation on energy efficiency

The adjustment of the air volume of the condenser not only affects the condensing pressure but also directly influences the energy efficiency of the system. It is pointed out that under the conditions of Tc=50℃, Te=7℃, Tsu=5℃, and Fz=80Hz, the relationship curves between the heat exchange capacity Q of the condenser and the air volume Gα and the air temperature Tα show that when the air volume increases, the heat exchange capacity gradually increases, but after the degree of subcooling increases, the increase rate of the heat exchange capacity slows down. Therefore, reasonably adjusting the air volume can increase the heat exchange capacity while avoiding unnecessary energy consumption.

It is further pointed out that by choosing the appropriate fan and adopting the variable frequency fan, the air volume can be adjusted according to the actual demand, thereby providing the appropriate air volume under different loads, improving the condensation efficiency, and reducing energy consumption at the same time.

3. The impact of condenser air volume regulation on seasonal energy efficiency

Seasonal Energy Efficiency (SEER) is a comprehensive indicator for measuring the operational performance of a refrigeration system in different seasons throughout the year. The adjustment of the condenser air volume can improve the overall energy efficiency of the system by optimizing the condensing pressure and heat exchange capacity, thereby enhancing the seasonal energy efficiency.

Research shows that when the compressor operates in a variable frequency mode, at low charge rates, the seasonal performance index IPLV.SI can be increased by 5%. This indicates that by adjusting the air volume of the condenser, the operating state of the compressor can be optimized, thereby enhancing the seasonal energy efficiency of the system.

It is mentioned that the condensing pressure of an evaporative condenser can be achieved by adjusting the air volume. For instance, an SP pressure controller is installed at the inlet of the hot ammonia pipe. When the condensing pressure is higher than the set value, the FM fan starts to operate; when it is lower than the set value, the fan stops. This regulation method can effectively control the condensing pressure, thereby improving the operational stability of the system.

4. The influence of condenser air volume regulation on the operation during transitional seasons

During the transitional season, the outdoor temperature is relatively low, and the condensation temperature may be too low, affecting the stable operation of the system. By adjusting the air volume of the condenser, the inlet air temperature can be increased, thereby avoiding problems caused by excessively low condensing temperature.

It is pointed out that when the outdoor temperature continues to drop, the system enters the winter operation mode. At this time, the fan or water pump can be regulated by frequency conversion to achieve small heat output, thereby ensuring the stable operation of the system.

It is pointed out that a lower cooling water supply temperature requires a larger air volume to increase the heat dissipation capacity of the cooling tower, so the fan will consume more electricity. Although a higher supply temperature of cooling water can save the power consumption of the cooling tower fan, it deteriorates the heat transfer effect of the condenser. To achieve the same air conditioning cooling load, the refrigeration machine needs to consume more electricity. Therefore, the supply water temperature (T_w, in) of the condenser must be optimized to reduce the total power consumption of the refrigeration machine and the cooling tower fans.

5. Implementation methods for regulating the air volume of the condenser

In order to achieve the optimal adjustment of the air volume of the condenser, multiple methods can be adopted:

Variable frequency fan: By adjusting the fan speed through a frequency converter, precise control of air volume is achieved, thereby enhancing the energy efficiency of the system.

Multi-fan control: By controlling the number of operating fans, the air volume can be adjusted to avoid pressure fluctuations caused by frequent starts and stops.

- Air volume regulating valve: Install an air volume regulating valve at the air inlet or outlet of the condenser. Control the air volume by adjusting the opening degree of the air damper.

- Temperature and pressure control: Adjust the cooling water flow rate based on the signal of the cooling water outlet temperature or condensing pressure to control the condensing pressure.

6. Conclusion

The air volume regulation of the condenser of low temperature chiller is of great significance for the improvement of seasonal energy efficiency. By reasonably adjusting the air volume, the condensing pressure can be optimized, the refrigeration efficiency and energy efficiency of the system can be improved, and thus the seasonal energy efficiency can be enhanced. In practical applications, appropriate adjustment methods should be selected based on the specific operating environment and system requirements to achieve efficient and stable operation of the system.