CN2708220Y - Highly-effective tray low-pressure evaporator for refrigerating plant - Google Patents

Abstract

A high-efficiency tray low-pressure evaporator for refrigeration equipment used in the technical field of refrigeration equipment. The liquid distributor is composed of a main pipe and several branch pipes. The diameter of the drainage pipe is larger than the outer diameter of the branch pipes of the liquid distributor. There is a gap between them. The drainage pipe Located between the liquid distributor and the tray, the tray is close to the lower part of the capillary evaporating tube row, and the gap between the capillary evaporating tube row and the capillary evaporating tube row is between 1 and 10 mm. The refrigerant is distributed, and the capillary evaporating tube is half immersed in the tray. The capillary evaporating tube is a high-efficiency heat transfer tube with reinforced outer wall, and there are a large number of capillary channels on the outer surface of the capillary evaporating tube. The utility model distributes the liquid evenly, does not need a refrigerant pump to circulate the liquid, and adopts a capillary evaporation tube on the outer wall. The cooled medium or some kind of steam is inside the tube, and the latent heat of evaporation is removed by convective heat exchange or steam condensation heat transfer. The low-pressure evaporation refrigerant is Capillary evaporation on the outer wall of the tube, and the tray plays the role of continuous liquid replenishment for capillary evaporation.

Description

High Efficiency Tray Low Pressure Evaporators for Refrigeration Units

technical field

The utility model relates to a tray low-pressure evaporator, in particular to a high-efficiency tray low-pressure evaporator for a refrigeration device. It is used in the technical field of refrigeration equipment.

technical background

In a refrigeration device using water or methanol as a refrigerant, the evaporation pressure in the evaporator is relatively low. If a submerged evaporator is used, it will be difficult for boiling evaporation to occur, resulting in the loss of refrigeration capacity of the refrigeration unit and the efficiency of the evaporator. However, if a spray-type falling-film evaporator is used, an expensive vacuum refrigerant pump is required, which not only increases power consumption but also reduces the operating reliability of the system. At present, in lithium bromide absorption refrigerators, falling film evaporators and disk liquid distributors are usually used for liquid distribution. During operation, the refrigerant liquid is required to have a certain liquid level in the liquid distributor to ensure uniform liquid distribution. When the amount of evaporation is small, the efficiency of this evaporator will be very low, liquid distribution will be difficult, and the power consumption ratio of the refrigerator pump will increase. Therefore, the existing evaporator forms limit the miniaturization of the absorption unit. Neither falling film nor submerged evaporators are the best choice for absorption and adsorption refrigeration systems with low power refrigeration.

After literature search, it was found that the patent application number: 93205862.0, named: Composite metal wire mesh tube falling film evaporator, this patent introduces an evaporator in which the heat exchange tube in the evaporation chamber is made of composite metal wire mesh tube. The metal wire mesh pipe is a pipe with 1 to 5 layers of wire mesh with a mesh number of 20 to 120 mesh on the inner and outer surfaces of the metal pipe, or pressure welded on the inner surface of the metal pipe to form 1 to 5 layers with a mesh number of 20 to 120 mesh. Wire mesh tube. The evaporator of this structure has been effectively enhanced in terms of heat transfer, but the fouling and fouling outside the evaporating tube is serious, its overall performance is not ideal, and its structure cannot meet the compactness requirements required by small refrigerators.

Contents of the invention

The purpose of this utility model is to provide a high-efficiency tray low-pressure evaporator for a refrigeration device, which does not have the problem of uneven liquid distribution and does not need a refrigerant pump to circulate liquid. The evaporator adopts a capillary evaporation tube on the outer wall. The cooled medium or some kind of steam is inside the tube. The latent heat of evaporation is taken away by convective heat exchange or steam condensation, and the refrigerant water or methanol is capillary evaporated on the outer wall of the tube. A tray is arranged close to the tube to continuously replenish liquid for capillary evaporation.

The utility model is realized by the following technical solutions, and the utility model comprises: a liquid distributor, a refrigerant, a drainage tube, a tray, and a capillary evaporation tube. The structural form of each part is as follows: the liquid distributor consists of a main pipe and several branch pipes. The diameter of the main pipe, the diameter and number of branch pipes are determined by the evaporation capacity. The diameter of the drainage tube is larger than the outer diameter of the branch pipe of the liquid distributor, and there is a gap between them. The drain tube is located between the liquid distributor and the tray to guide the condensate into the tray. The condensate is evenly distributed to each branch pipe of the liquid distributor through the liquid distributor, and then evenly distributed to each tray through the drainage tube to complete the "one-time" liquid distribution. The tray is close to the lower part of the capillary evaporating tube row, the gap between the capillary evaporating tube row and the capillary evaporating tube row is between 1 and 10 mm, and the flange height is between 3 mm and the radius of the capillary evaporating tube. Trays and capillary evaporation tubes are arranged horizontally. A tray is installed at the bottom of each row of capillary evaporating tubes, refrigerant is distributed in the tray, and the capillary evaporating tubes are half immersed in the tray. The capillary evaporation tube is a high-efficiency heat transfer tube with reinforced outer wall, which can be processed by two processes, one is the outer surface wire-rolled tube, and the other is the outer surface wire mesh or metal powder sintering process. A large number of capillary channels with a diameter of 0.1 to 0.5 mm are processed on the outer surface of the capillary evaporation tube. The condensate is arranged in the tray through the liquid distributor and the drainage tube, and then the "secondary" liquid distribution is completed through the capillary action of the outer surface of the capillary evaporation tube on the refrigerant. For low-power evaporators, due to the small number of trays, the utility model can also remove the liquid distributor, directly through the liquid inlet pipe, and arrange the refrigerant on the top tray, and the next tray is close to the overflow of the upper tray. The flow realizes the liquid distribution of the refrigerant.

The utility model utilizes the liquid distributor to evenly arrange the refrigerant into each tray. Since the number of trays is small, generally only 3 to 15, it is easy to ensure that the amount of refrigerant arranged in each tray is consistent. For low-power evaporators without liquid distributors, the refrigerant arranged in the upper tray continuously overflows the tray and flows into the lower layer by gravity, thus playing the role of liquid distribution. Under the action of capillary force, the refrigerant is further evenly arranged on the outer wall of the capillary evaporation tube. Another fluid or vapor in the capillary evaporator tube takes away the latent heat of evaporation of the refrigerant by means of convective heat transfer or condensation heat transfer process. Refrigerant is added to the outer wall of the capillary evaporation tube to realize the liquid distribution and evaporation of the refrigerant in the capillary evaporation tube at a ratio of 1:1, so that the evaporation process is carried out continuously, and the evaporation process does not require a refrigerant pump.

The utility model utilizes the capillary capacity of the surface of the liquid distributor and the capillary evaporating tube to evenly distribute the condensate to the evaporating surface of the capillary evaporating tube, realizes the operating mode of the evaporator without a refrigerant pump, and saves manufacturing and operating costs. The utility model is especially suitable for small and medium-sized absorption and adsorption refrigeration machines. In addition, the capillary surface of the capillary evaporation tube expands the evaporation surface, strengthens the evaporation heat exchange capacity of the evaporator, and improves the efficiency of the evaporator.

Description of drawings

Fig. 1 The utility model includes the schematic structural diagram of the liquid distributor

Fig. 2 is a schematic structural diagram of the utility model omitting the liquid distributor

Detailed ways

As shown in FIG. 1 , the utility model includes: a liquid distributor 1 , a refrigerant 2 , a drainage tube 3 , a tray 4 , and a capillary evaporation tube 5 . The liquid distributor is composed of a main pipe and several sub-pipes. The diameter of the main pipe, the sub-pipe diameter and the number are determined by the evaporation capacity. The diameter of the drainage tube 3 is larger than the outer diameter of the sub-pipe of the liquid distributor 1, and there is a gap between them. The drainage tube 3 is located between the liquid distributor 1 and the tray 4, and the tray 4 is close to the lower part of the capillary evaporation tube 5 tube row, and the gap between the capillary evaporation tube 5 tube row is between 1 and 10 mm, and the flange height is between 1 and 10 mm. Between 3 mm and 5 radii of the capillary evaporation tube. Both the tray 4 and the capillary evaporation tube 5 are arranged horizontally. A tray 4 is installed at the bottom of each row of 5 capillary evaporating tubes, the tray 4 is covered with refrigerant 2 , and the capillary evaporating tubes 5 are half immersed in the tray 4 . The capillary evaporation tube 5 is a high-efficiency heat transfer tube with reinforced outer wall. There are a large number of capillary channels with a diameter of 0.1 to 0.5 mm on the outer surface of the capillary evaporation tube 5 .

As shown in FIG. 2 , for a low-power evaporator, the liquid distributor 1 is omitted, and the refrigerant 2 is arranged on the top tray 4 by directly setting the liquid inlet pipe 6 on the top of the top tray 4 .

The capillary evaporating tube 5 is an outer surface strengthening tube, and the outer surface of the tube is a capillary surface of wire rolling, metal powder sintering, and multi-layer wire mesh sintering.

Claims (4)

1, a kind of refrigerating plant is with efficient pallet low pressure evaporator, comprise: liquid distributor (1), cold-producing medium (2), capillary evaporation pipe (5), it is characterized in that, also comprise: drainage tube (3), pallet (4), liquid distributor (1) is made up of a house steward and some being in charge of, the diameter of drainage tube (3) divides external diameter of pipe greater than liquid distributor (1), leave the gap between them, drainage tube (3) is positioned between liquid distributor (1) and the pallet (4), pallet (4) is close to capillary evaporation pipe (5) pipe row bottom, and the gap between capillary evaporation pipe (5) the pipe row is between 1 to 10 millimeter, and each capillary evaporation pipe (5) pipe row bottom is provided with pallet (4), be furnished with cold-producing medium (2) in the pallet (4), capillary evaporation pipe (5) partly is immersed in the pallet (4), and capillary evaporation pipe (5) is the efficient heat conducting tube that outer wall is strengthened, and a large amount of diameters is arranged at 0.1 to 0.5 millimeter capillary channel at the outer surface of capillary evaporation pipe (5).

2, a kind of refrigerating plant is characterized in that with efficient pallet low pressure evaporator, for the small-power evaporimeter, omits liquid distributor (1), on top layer pallet (4) top feed tube (6) is set, and cold-producing medium is arranged in the top layer pallet (4).

3, evaporimeter according to claim 1 and 2 is characterized in that, pallet (4) and capillary evaporation pipe (5) all adopt horizontally disposed, the flange height of pallet (4) at 3 millimeters between capillary evaporation pipe 5 radiuses.

4, evaporimeter according to claim 1 and 2 is characterized in that, capillary evaporation pipe (5) is the outer surface enhanced tube, and tube outer surface is for rolling silk, metal powder sintered, multi-layer silk screen sintering capillary surface.

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