Full-falling-film evaporator and water chilling unit

Abstract

The invention provides a full-falling-film evaporator and a water chilling unit, being applicable to the technical field of refrigeration air conditioners. The full-falling-film evaporator comprises an evaporator shell formed by an evaporator barrel and a tube sheet, wherein the evaporator shell is internally provided with a plurality of falling-film evaporating pipes, pipe bundles formed by the plurality of falling-film evaporating pipes are supported by at least one pipe support plate, at least two distributing plates are arranged between the pipe bundles, the distributing plates divide the pipe bundles into a plurality of pipe bundle layers, a gas-liquid two-phase distributor is arranged between the pipe bundle layer at the uppermost layer and the barrel, the top of the barrel is provided with a gas-liquid two-phase refrigerating medium inlet pipe and a gaseous refrigerating medium air-return pipe, and the bottom of the barrel is provided with at least one refrigeration oil return pipe. According to the full-falling-film evaporator and the water chilling unit which are disclosed by the invention, the full-falling-film evaporation is truly achieved, the heat transfer coefficient is enhanced, and the refrigerant charge is reduced, therefore the purpose of energy saving and environmental protection are achieved.

Description

technical field [0001] The invention belongs to the technical field of refrigeration and air conditioning, and more specifically relates to a full falling film evaporator and a chiller using the full falling film evaporator. Background technique [0002] At present, the evaporators used by chillers in the refrigeration and air-conditioning industry usually include dry evaporators, flooded evaporators, and falling film evaporators. Among them, falling film evaporators have excellent heat transfer performance and refrigerant charging The advantages of less fluence, etc., have been widely promoted in the application of chiller evaporators in the refrigeration and air-conditioning industry in recent years. However, among the falling film evaporators that appear in the industry at present, one type is the so-called "mixed falling film evaporator" that can only realize part of the tube bundle falling film evaporation and part of the tube bundle flooded evaporation, see the attache...

AI Technical Summary

Problems solved by technology

However, among the falling film evaporators that appear in the industry at present, one type is the so-called "mixed falling film evaporator" that can only realize part of the tube bundle falling film evaporation and part of the tube bundle flooded evaporation, see the attached figure 1 , attached figure 2 And attached image 3 The other is that it is difficult to control and realize the falling film evaporation of all tube bundles because there are no multiple distribution devices between the tube bundles. The middle and lower parts of the tube bundles of this type of falling film evaporator are prone to "dry spots", resulting in evaporator The overall heat transfer performance is greatly deteriorated. Generally, in order to avoid the above-mentioned "dry spots", this type of falling film evaporator usually adopts the way of refrigerant overspray, so that a certain amount of refrigerant liquid is inevitably left at the bottom of the evaporator. At this time, or the bottom of the evaporator is full of liquid evaporation, which is exactly the same as the above-mentioned "hybrid falling film evaporator", or the liquid refrigerant accumulates at the bottom of the evaporator and cannot be evaporated, which greatly increases the refrigerant in the evaporator. charge, see attached Figure 4 , attached Figure 5

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