The flow channel optimization of the plate heat exchanger of low temperature chiller has a significant impact on frost suppression. By optimizing the flow channel design, the formation and accumulation of frost layers can be effectively reduced, thereby enhancing the thermal performance and operational efficiency of the heat exchanger. The following is a detailed analysis of this issue:

The influence of flow channel optimization on frost layer distribution

Flow channel optimization can be achieved by adjusting the fin spacing, setting up frost-attracting sections and frost-collecting plates, etc., to guide the air flow path, concentrating the frost layer in a specific area or reducing the uniform distribution of the frost layer. For instance, it is mentioned in the literature that by adjusting the fin spacing and channel spacing, the heat exchange performance of the heat exchanger and the uniformity of frosting on both the front and rear sides can be improved. In addition, the literature also points out that the heat exchange efficiency of the slotted finned tube heat exchanger is higher than that of the flat finned tube heat exchanger, but its pressure loss is relatively large. This indicates that the flow channel optimization needs to strike a balance between heat exchange efficiency and pressure loss.

2. The influence of flow channel optimization on heat exchange performance

The thermal resistance of the frost layer is very large, which will significantly reduce the heat exchange capacity of the heat exchanger. It is mentioned in the literature that when the frost layer thickness reaches 1.5mm, the efficiency of the heat exchanger decreases by approximately 10%, and at the same time, the flow resistance increases. In severe cases, the flow channels of the heat exchanger may be blocked. Therefore, optimizing the flow channel design can reduce the formation of frost layers, thereby lowering thermal resistance and enhancing heat exchange efficiency. For example, the circuit optimization method proposed in the literature, by adjusting the flow channel configuration, can achieve a 11.6% increase in HX capacity and a 5.1% reduction in frosting mass. This indicates that the optimization of the flow channel not only helps to improve the heat exchange efficiency but also reduces the accumulation of frost.

3. The influence of flow channel optimization on defrosting operation

The accumulation of frost will increase the frequency and duration of defrosting operations, thereby affecting the operational efficiency of the system. It is mentioned in the literature that optimizing the flow channel design can extend the operating time of the evaporator between defrosting operations. For example, the genetic algorithm optimization method proposed in the literature can reduce the blockage of the air flow path, thereby prolonging the running time between defrosting operations. This indicates that flow channel optimization not only helps to reduce frosting, but also reduces the frequency of defrosting operations and improves the overall efficiency of the system.

4. The influence of flow channel optimization on air flow

Flow channel optimization can reduce the formation of frost layers by adjusting the air flow path. For instance, it is mentioned in the literature that the heat exchange performance can be improved by increasing the mass and size of the heat exchanger. In addition, the literature also mentions that by adjusting the air flow path, the formation of frost layers can be reduced, thereby improving the thermal performance of the heat exchanger. For instance, the four common anti-frosting strategies for fixed plate heat exchangers presented in the literature include preheating circuits, exhaust valves, reflux air and reflux air with surface flow, and bypass valves. These strategies control air flow through different valve configurations to ensure the normal operation of the heat exchanger in low-temperature environments.

5. The influence of flow channel optimization on frost layer thickness

Flow channel optimization can reduce the thickness of the frost layer by reducing its formation. It is mentioned in the literature that when the temperature of the coolant is lower, the heat exchange capacity and frosting amount of the microchannel heat exchanger are greater. Therefore, optimizing the flow channel design can reduce the formation of frost layers, thereby reducing the thickness of the frost layers. For instance, it is mentioned in the literature that when the mass ratio of anhydrous methanol is 1.25, the heat exchange rate of the precooler is the highest because the thermal resistance of the frost layer or ice layer is significantly reduced. This indicates that the flow channel optimization can reduce the thickness of the frost layer by reducing the formation of the frost layer and thereby improve the thermal performance of the heat exchanger.

The flow channel optimization of the plate heat exchanger of low temperature chiller has a significant impact on frost suppression. By optimizing the flow channel design, the formation and accumulation of frost layers can be reduced, thereby enhancing the thermal performance and operational efficiency of the heat exchanger. Flow channel optimization not only helps to improve heat exchange efficiency, but also reduces the frequency of defrosting operations and enhances the overall efficiency of the system. In addition, flow channel optimization can also reduce the thickness of the frost layer, thereby improving the thermal performance of the heat exchanger.