How to choose a plate heat exchanger? How to apply in HVAC field?


How to choose a plate heat exchanger? How to apply in HVAC field

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Selection principles and key points of plate heat exchangers:

  1. Selection principle

Principle 1: Kanban

  1. The plate type or corrugated type should be determined according to the actual needs of the heat exchange occasion.
  2. When the flow rate is large and the allowable pressure drop is small, the plate type with small resistance should be selected, otherwise, the plate type with large resistance should be selected.
  3. According to the fluid pressure and temperature, determine whether to choose a detachable type or a brazing type.
  4. When determining the plate type, it is not advisable to choose a plate with too small a single plate area, so as to avoid too many plates, a small flow rate between plates, and a low heat transfer coefficient. For larger heat exchangers, more attention should be paid to this problem.

Principle 2: Look at the process and flow channel

The process refers to a group of parallel flow channels in the same flow direction of a medium in the plate heat exchanger, and the flow channel refers to the medium flow channel composed of two adjacent plates in the plate heat exchanger. Generally, several flow channels are connected in parallel or in series to form different combinations of cold and hot medium channels.

The process combination form should be determined on the basis of heat transfer and fluid resistance calculations and satisfying the requirements of the process conditions. Try to make the convective heat transfer coefficients in the cold and hot water channels equal or close to get the best heat transfer effect. Because the convective heat transfer coefficient on both sides of the heat transfer surface is equal or close to the larger value of the heat transfer coefficient. Although the flow rate between the plates of the plate heat exchanger is different, the average flow rate is still used for the calculation of heat transfer and fluid resistance. Since the connecting pipes of the "U"-shaped single process are all fixed on the pressing plate, it is easy to disassemble and assemble.

Principle 3: Check the pressure drop

In the design and selection of plate heat exchangers, there are generally certain requirements for pressure drop, so it should be checked. If the checked pressure drop exceeds the allowable pressure drop, it is necessary to re-calculate the design and selection until the process requirements are met.

 

Application of plate heat exchanger in HVAC field:

district heating system

Combined heat and power system

geothermal heating system

Instant domestic hot water system

The instant heating feature can ensure that users can have hot water supply anytime and anywhere. The system is compact and does not require storage tanks. Larger boiler capacity requires larger heat exchangers.

Semi instantaneous domestic hot water system

The semi-instantaneous feature requires a smaller boiler capacity, a smaller heat exchanger, easy to grow bacteria in the storage tank, and requires an additional place to place the storage tank.

Advantages of plate heat exchangers in cooling and air-conditioning systems 1. High heat transfer coefficient, and the logarithmic temperature difference can reach 0.5 degrees. 2. Small size, light weight, easy to install, can be placed on the equipment floor. 3. Easy to disassemble, convenient to clean the internal dirt. 4. The structure is solid and can withstand high working pressure, up to 3.0MPa. 5. High heat exchange efficiency, reducing operating costs. 6. Low fixed investment.

 

Jiangsu Yuanzhuo Equipment Manufacturing Co., Ltd.is a professional manufacturer of plate heat exchangers. Plate heat exchangers are widely used. We have Brazed Plate Heat Exchangers and Gasketed Plate Heat Exchangers. If you are interested in plate heat exchangers, please feel free to contact us to 0086-510-86165907 or send an email to zy@jsyuanzhuo.com.

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