A horizontal tube falling film evaporator

Abstract

The invention discloses a horizontal tube falling film evaporator, which comprises a shell with a liquid inlet and a gas outlet, the liquid inlet is connected with the liquid inlet, the gas outlet is connected with the gas outlet, and the casing includes a liquid distributor , the first diversion liquid distribution device, the second diversion liquid distribution device, the first-stage heat exchange tube group, the second-stage heat exchange tube group and the third-stage heat exchange tube group, the liquid inlet pipe is connected with the liquid distributor, and the liquid distributor From top to bottom, there are the first-level heat exchange tube group, the first flow guide and liquid distribution device, the second-level heat exchange tube group, the second flow guide and liquid distribution device, and the third-level heat exchange tube group. The heat exchange tubes of the heat exchange tube group, the secondary heat exchange tube group and the tertiary heat exchange tube group are all equipped with turbulent spiral twisted belts. The invention can make the temperature distribution of the refrigerant in the tubes more uniform and improve the heat exchange effect; the invention collects the liquid working medium flowing down from the previous process and conducts diversion and redistribution, which is beneficial to the liquid working medium in the lower tube bundle to be distributed more evenly.

Description

technical field [0001] The invention belongs to the technical field of evaporators, in particular to a horizontal tube falling film evaporator. Background technique [0002] The horizontal tube falling film evaporator belongs to the category of shell and tube heat exchanger. The cold medium runs inside the heat exchange tube; outside the heat exchange tube, the low-temperature and low-pressure refrigerant liquid from the throttle valve is evenly sprayed on the heat transfer tube bundle, and spreads on the tube wall to form a film, absorbing the heat of the fluid in the tube and partially evaporating. The refrigerant liquid that descends the film to the bottom of the evaporator under the action of gravity submerges a part of the heat exchange tube, which is called the submerged area of ​​the falling film evaporator. The vapor generated by evaporation is sucked into the compressor after passing through the gas-liquid separation device such as the liquid baffle, so as to conti...

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Problems solved by technology

[0008] Although the falling film evaporator has great advantages in efficiency, economy and environmental protection in theory, there are still many problems in practical engineering applications: due to the installation deviation of the liquid distributor, the different evaporation degrees of refrigerants in different processes, and the The flow of high-quality steam will lead to local dry areas on the surface of the heat exchange tubes, which will reduce the heat transfer coefficient; at the same time, due to the characteristics of falling film evaporation, the local heat transfer coefficient of the liquid impact area on the upper part of each heat exchange tube will be the highest, resulting in cooling in the tubes. The temperature distribution of the agent is uneven, which also reduces the efficiency of heat transfer to a certain extent.

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