Is brazed plate heat exchanger bigger better?

Is brazed plate heat exchanger bigger better?


Is brazed plate heat exchanger bigger better? Brazed plate heat exchanger is widely used because of its high heat transfer coefficient and convenient use. However, due to its own design reasons, the larger the heat transfer coefficient is, the better the heat transfer coefficient is. The actual operation conditions should be taken into account in the design and application.


Is brazed plate heat exchanger bigger better? Especially when the brazed plate heat exchanger is selected as evaporator, if it is too large, there will be the following problems:


1. With the increase of cost, the plate heat exchanger has been enlarged and the product cost has been increased, which is well understood. At the same time, it's not that the bigger, the more efficient.


2. The evaporator is unable to return oil, causing the compressor to burn out due to lack of oil


3. Evaporator performance will continue to decline.


4. Uneven refrigerant distribution


When the brazed plate heat exchanger is used as the evaporator, it is too large, and the flow rate of refrigerant drops, which makes it difficult, and the compressor is destroyed. There is a large amount of oil in the plate heat exchanger pipeline. On the one hand, due to the flow rate, the oil can not be returned, and the compressor is short of oil and burned. On the other hand, the oil in the plate evaporator accumulates in the pipeline, adheres to the wall surface of the stainless steel plate, forms dirt, reduces the heat transfer coefficient, reduces the evaporation temperature, causes the system performance to decline, this kind of situation is also easy to occur in the low-temperature system, because the fluid heat transfer coefficient is relatively low when doing low temperature, In this case, we must consider the problem of oil return.


The evaporator is too large and the refrigerant distribution is uneven. Because the area of the heat exchanger is too large, even if there is a distributor, the required refrigerant flow of each channel is reduced, or the refrigerant is not evenly distributed in each channel, resulting in the decrease of refrigeration effect.


Therefore, when the heat exchanger of brazed plate heat exchanger is used as evaporator or refrigeration system, it is not allowed to select a large one. Other parts such as expansion valve, solenoid valve, etc. should also be matched properly. The whole operation condition must be taken into consideration to prevent the heat exchanger from being too large or too small.