The selection of the plate heat exchanger flow rate can have a key impact on the heat transfer effect, energy consumption, and operating costs. Below we will introduce in detail the precautions when using the plate heat exchanger as a condenser and evaporator.
1. Generally, both condensation and boiling can be completed in one process. Therefore, the phase change side is often arranged as a single process, and the liquid side can be arranged as a single pass or multiple passes as needed. In the field of HVAC and refrigeration, the water side is generally a single process.
2. For plate condensers, generally do not allow the condensation section and the subcooling section to coexist during design. Because the heat exchange efficiency of the subcooling section is low, if subcooling is required, in principle, a separate subcooler should be installed.
3. There is also an allowable pressure drop problem in the design of plate condensers and evaporators. A large pressure drop in the condenser will reduce the condensation temperature of the steam, resulting in a small logarithmic average temperature difference; a large pressure drop in the evaporator will increase the superheat of the outlet steam. Both will increase the area of the heat exchanger, which is harmful to the situation. Heat exchange is disadvantageous. Therefore, when selecting a plate evaporator, you should try to choose plates with smaller resistance, and the number of plates per unit should not be too many; try to distribute the liquid supply evenly. Plate condensers should use a middle partition to distribute liquid to both sides.
4. When selecting, the structural types of plate condenser and plate evaporator should be given priority. If there is no suitable model, the commonly used general plate heat exchanger can be selected.
5. For plate heat exchangers used in refrigeration and air-conditioning equipment, due to the high refrigerant pressure and strong leakage capacity, brazed plate heat exchangers should be used.
The issues that should be paid attention to when using plate heat exchangers as condensers and evaporators are the above points. Users who purchase plate heat exchangers for this purpose must pay special attention to the above issues during use, so as to maximize It can maximize the performance of the plate changer, reduce engineering investment, and ensure that its service life is not affected.
Post time: Dec-06-2023