The plate heat exchanger is a high-efficiency heat exchanger made up of a series of metal sheets with a certain corrugated shape. Thin rectangular channels are formed between various plates, and heat exchange is carried out through the plates. It has the characteristics of high heat exchange efficiency, low heat loss, compact and lightweight structure, small footprint, wide application and long service life. The application of plate heat exchangers is gradually widespread, and the number of manufacturers producing plate heat exchangers is gradually increasing. The unevenness of manufacturers leads to uneven quality of plate heat exchangers, so how should high-quality plate heat exchangers be purchased?
(1) Skills of plate heat exchanger selection and calculation
Under normal circumstances, the design and selection of plate heat exchangers have certain requirements for pressure drop. First, it must be checked and then determined. If the proof pressure drop exceeds the allowable pressure drop, the design and selection calculations need to be re-calculated until the process requirements are met.
(2) Selection of plate heat exchanger process and flow channel
Generally, several runners are connected in parallel or in series to form different combinations of cold and hot medium channels. The process combination form should be calculated based on heat exchange and fluid resistance, and determined under the requirements of process conditions. The heat exchanger is designed so that the convective heat transfer coefficients in the cold and hot water channels are equal or close to obtain the best heat transfer effect. Although the flow velocity between the plates of the plate heat exchanger is not equal, the average flow velocity is still used when calculating heat exchange and fluid resistance.