CN-121994069-A - Falling film evaporator and distributor suitable for single flow heat exchange

CN121994069ACN 121994069 ACN121994069 ACN 121994069ACN-121994069-A

Abstract

The invention discloses a falling film evaporator and a distributor suitable for single-flow heat exchange, wherein a liquid supply pipe and an air suction pipe are arranged at positions far away from a water inlet side, the liquid supply pipe is communicated with a distribution box, a main structure of the distribution box is divided into a plurality of areas along the length direction of a cylinder, and distribution flow of the areas is distributed in a gradient manner along the length direction so as to realize that the distribution of flow of a water inlet side is more and the distribution of flow of a water outlet side is less. The heat exchange gradient requirement of a single flow in the length direction is met, the heat exchange area and the refrigerant quantity are saved, the heat exchange gradient device is suitable for a single-flow large-cooling unit, meanwhile, the processing is convenient and simple, the realization is easy, and the suction liquid carrying risk can be avoided to the greatest extent.

Inventors

CHENG MAN
WANG DA
WU JINGJING
ZHOU JIE
MA XIN
LUO XIONG
MA YINFENG

Assignees

麦克维尔空调制冷(武汉)有限公司

Dates

Publication Date: 20260508
Application Date: 20241106

Claims (10)

1. Falling film evaporator suitable for single-flow heat transfer, the evaporator barrel is horizontal, and water inlet side and water outlet side are located barrel both ends, its characterized in that: the liquid supply pipe and the air suction pipe are arranged at positions far away from the water inlet side, and the liquid supply pipe is communicated with the distribution box; the distribution box is arranged above the falling film zone heat exchange tube group and the full liquid zone heat exchange tube group and is transversely arranged between the water inlet side and the water outlet side; The distribution box main body structure is divided into a plurality of areas along the length direction of the cylinder body, and the distribution flow of the areas is distributed in a gradient manner along the length direction, so that the distribution of the inflow and the outflow flows is more and the distribution of the outflow flows is less.
2. The falling film evaporator suitable for single pass heat exchange of claim 1 wherein the distributor box body structure is divided into a plurality of zones along the length of the barrel.
3. The falling film evaporator suitable for single flow heat exchange according to claim 1, wherein the distribution box main body structure is divided into a plurality of areas along the length direction of the cylinder, and the distribution flow rate of each area along the length direction is arranged in a gradient manner.
4. The falling film evaporator suitable for single-flow heat exchange according to claim 1 is characterized in that the distribution box is divided into two stages, the first-stage distribution box is a rectangular pressure distribution box, uneven first-stage outlet holes are distributed on two corresponding side walls of the rectangular box body along the length direction of the barrel body, the rectangular box body is connected with a liquid inlet, the liquid inlet is arranged far away from a water inlet side, the second stage is a gravity distribution box, uneven second-stage distribution holes are arranged at the horizontal bottom, and the arrangement relation of the first-stage outlet holes and the second-stage distribution holes is that holes close to the water inlet side are arranged densely, and holes far away from the water inlet side are arranged more sparsely.
5. The falling film evaporator suitable for single-flow heat exchange according to claim 1, wherein the first-stage outlet holes and the second-stage distribution holes are respectively provided with a plurality of areas along the length direction of the cylinder, and each area of each stage is arranged from dense to sparse along the length direction, so that the open pore flow area close to the water inlet side is large, and the flow area is small when the open pore flow area is far away.
6. The falling film evaporator suitable for single-flow heat exchange according to claim 1, wherein a ventilation window is arranged at the top of the distribution box, a ventilation cover with a horizontal baffle plate shape at the top is arranged on the ventilation window, the ventilation cover is arranged away from the air suction hole and the liquid inlet, and an opening arranged towards the tube plate at the water inlet side of the cylinder is formed between one end of the horizontal baffle plate and the cylinder.
7. The falling film evaporator suitable for single-flow heat exchange according to claim 1, wherein the primary outlet holes and the secondary distribution holes are respectively provided with 3 areas along the length direction of the cylinder, and each area of each stage is arranged from dense to sparse along the length direction, so that the open pore flow area close to the water inlet side is large, and the flow area is small when the open pore flow area is far away.
8. The falling film evaporator suitable for single flow heat exchange of claim 1, wherein the side wall of the rectangular box body of the first stage distribution box close to the liquid inlet is not perforated.
9. The distributor is arranged above the falling film zone heat exchange tube group and the full liquid zone heat exchange tube group and is characterized by being transversely arranged between a water inlet side and a water outlet side; The two-stage pressure distribution box comprises a rectangular pressure distribution box, wherein the rectangular box body is provided with uneven first-stage outlet holes along two corresponding side walls of the length direction of the barrel, the rectangular box body is connected with a liquid inlet, the liquid inlet is arranged far away from the water inlet side, the second-stage pressure distribution box is provided with uneven second-stage distribution holes at the horizontal bottom, and the arrangement relation of the first-stage outlet holes and the second-stage distribution holes is that holes close to the water inlet side are arranged densely, and holes far away from the water inlet side are arranged more sparsely.
10. The dispenser of claim 9, wherein the bottom of the secondary distribution box is provided with non-uniform distribution holes, and the flow area of the holes near the water inlet side is large, and the flow area is small when the holes are far away.

Description

Falling film evaporator and distributor suitable for single flow heat exchange Technical Field The application relates to the technical field of air conditioning heating and ventilation, in particular to a falling film evaporator structure for single-flow heat exchange, wherein an evaporator distributor is uniformly distributed in an inner set. Background The refrigerating system or the water chilling unit mainly comprises a compressor, an evaporator, a condenser and a throttling device. Along with the increasing requirements of energy conservation and environmental protection, research on water chilling units has been conducted in the direction of high performance and low energy consumption, in a conventional air conditioning system, the energy consumption ratio of the water chilling units and a water pump is about 74%, and the serial countercurrent arrangement scheme of a plurality of water chilling units is also increasingly widely applied in large units due to obvious energy conservation effect. The falling film evaporator has the advantages of small refrigerant filling amount, compact structure, high heat transfer efficiency, stable heat exchange and the like, and is widely applied to the field of refrigeration and air conditioning. Because of the limitation of water side pressure drop and the increase of energy efficiency requirements of the unit, the unit often adopts a serial countercurrent configuration. In short, the series countercurrent flow refers to the series connection of two water chilling units, and the flow direction of chilled water and cooling water has special requirements that the chilled water firstly passes through an upstream water chilling unit evaporator and then passes through a downstream water chilling unit evaporator, and the flow direction of cooling water is opposite and preferably passes through a downstream water chilling unit condenser and then passes through an upstream water chilling unit condenser. Compared with the conventional water chilling unit arrangement, the water chilling unit can share one chilled water pump and one cooling water pump, so that energy is saved, the pipeline arrangement is simplified, and the occupied area is saved. When a series countercurrent type water chiller is used, a single unit system waterway is often in a single flow path. Because the main flow water chilling unit evaporator adopts a two-flow or multi-flow mode, the heat flux density distribution of the evaporator along the length direction is relatively uniform. However, in the series countercurrent type water chilling unit, the evaporator adopts the uniflow Cheng Xingshi, and the heat flow density of the heat exchanger along the length direction is uneven along the distribution of the heat flow density along the length direction because the temperature difference of the heat exchanger along the length direction is smaller and smaller, so that the heat flow density of the water inlet side is high, and the heat flow density of the water outlet side is low. Therefore, for the falling film evaporator, if flow distribution is uniform along the length direction, flow distribution of the inlet side is small, the flow of the inlet side falling film and the tube bundle of the full liquid area are easy to dry up, so that heat exchange efficiency is reduced, flow distribution of the outlet side is excessive, a liquid film is thick, but heat exchange is not participated in, so that heat exchange efficiency of the whole area is reduced, refrigerant liquid is wasted, heat exchange area cannot be fully utilized, and the whole heat exchange area loss can reach 30%. If the outside of the water inlet side pipe is not dried, the method generally adopted is to increase the amount of the refrigerant, and at this time, the deterioration of the heat exchange at the far water side and the waste of the refrigerant are caused. Disclosure of Invention The application aims at solving the technical problems that the falling film evaporator and the distributor structure suitable for single-flow heat exchange are provided for the heat exchange condition of the single-flow falling film evaporator, the heat exchange gradient requirement of the single-flow in the length direction is met, the heat exchange area and the refrigerant quantity are saved, the falling film evaporator and the distributor structure are suitable for single-flow large-cooling-capacity units, meanwhile, the processing is convenient and simple, the realization is easy, and the risk of liquid carrying during air suction can be avoided to the maximum extent. In order to solve the technical problems, the invention adopts the following technical scheme: falling film evaporator suitable for single-flow heat transfer, the evaporator barrel is horizontal, and water inlet side and water outlet side are located barrel both ends, its characterized in that: the liquid supply pipe and the air suction pipe are arranged at positions far away from the water in