Tubular heat exchanger is currently the most widely used heat exchanger in chemical production. Its main advantages are that the heat transfer area per unit volume (40-150mZ / m3) is large and the heat transfer effect is good. In addition, the tube heat exchanger has a simple structure, a wide range of manufacturing materials, and strong adaptability, especially in high temperature, high pressure, and large-scale installations.The plate heat exchanger is a new type of heat exchanger. Its main advantages are compact structure, large heat transfer area (250-1000mZ / m3) per unit volume, less material consumption, and large heat transfer coefficient. The number of plates can be arbitrarily increased or decreased to adjust the heat transfer area. In addition, maintenance and cleaning are very convenient, and its use range is expanding.The performance of the tube-and-tube heat exchanger and plate heat exchanger are compared below.
In the tube-and-tube heat exchanger, the temperature of the shell and the tube bundle are also different due to the different temperatures of the hot and cold fluids. As a result, they also differ in the degree of thermal expansion. If the temperature of the two fluids is greatly different (for example, above 50 ° C), the equipment may be deformed due to stress, or even bent and broken, or the tube may be loosened from the tube sheet. Therefore, appropriate temperature difference compensation measures must be adopted to eliminate or reduce thermal stress.According to the corrugated geometry, the plates of the plate heat exchanger are divided into horizontal flat corrugations, herringbone corrugations, and diagonal corrugations. According to the flow morphology of the fluid between the plates, there are corrugated plates with tubular flow, band flow, and net flow.The main parameters of the corrugated plate performance are heat transfer efficiency, flow resistance and pressure bearing capacity.Generally speaking, herringbone corrugated sheet has high heat transfer efficiency, large fluid resistance and good pressure bearing capacity. Horizontal flat corrugated sheet has lower heat transfer efficiency and less fluid resistance than herringbone corrugated sheet. The pressure capacity is also slightly lower.