CN112923747A

CN112923747A - Novel dry-wet cooling tower and evaporative condenser

Info

Publication number: CN112923747A
Application number: CN201911240583.4A
Authority: CN
Inventors: 熊哲仑; 任敏
Original assignee: Fangnuo Heat Transfer System Jiangsu Co Ltd
Current assignee: Fangnuo Heat Transfer System Jiangsu Co Ltd
Priority date: 2019-12-06
Filing date: 2019-12-06
Publication date: 2021-06-08

Abstract

The invention provides a novel dry and wet cooling tower and an evaporative condenser, which comprise: the heat exchanger comprises an equipment frame, wherein an upper layer of basic heat exchange units and a lower layer of basic heat exchange units are arranged in the equipment frame, a water collecting tank is arranged at the bottom of the equipment frame, and a fan is arranged at the top of the equipment frame; each layer of basic heat exchange units is provided with two opposite groups, and each layer of basic heat exchange units comprises: the device comprises a fin heat exchanger and a spray heat exchanger, wherein the fin heat exchanger is arranged close to the side wall of the equipment frame, and the spray heat exchanger is arranged on one side of the fin heat exchanger, which is far away from the side wall of the equipment frame; a spray header connected with a water collecting tank pipeline is arranged above each layer of basic heat exchange units; the outside air passes through the fin heat exchanger, the louver and the spray heat exchanger in sequence, the temperature reduction from dry cooling to wet cooling is combined, the heat exchange efficiency is improved, the upper and lower stacked heat exchange is adopted, and the energy and water conservation is realized by matching with multiple water collection and distribution.

Description

Novel dry-wet cooling tower and evaporative condenser

Technical Field

The invention relates to the technical field of cooling towers, in particular to a novel dry-wet cooling tower and an evaporative condenser.

Background

The dry-wet combined cold water device is characterized in that a piece assembly is additionally arranged at the rear end of a traditional closed cooling coil to form an air cooling effect and realize water saving, and the existing dry-wet combined cold water technology has the major technical defects on the heat exchange process: the heat exchange sequence for ambient air is evaporation effect heat exchange before temperature difference effect heat exchange after evaporation effect heat exchange.

The physical property data show that: the saturated vapor pressure of the humid air at low temperature is far less than the value of the humid air at high temperature, so that the heat exchange process of the evaporation effect is preferably carried out at high temperature; the heat exchange process of the temperature difference effect is reasonable at low temperature, and the root cause of the paradox phenomenon is that the ambient air can only exchange heat with the wet section firstly in the flow caused by the layout of the heat exchange components of the traditional dry-wet combined water cooling device in the dry section (because the heat exchange characteristic is the temperature difference effect, the patent refers to air cooling section) and the wet section (because the heat exchange characteristic is evaporation effect, the patent refers to evaporation section) in the front.

The dry-wet combined cooling water technology generally uses a certain temperature value (usually 0-5 ℃) as a control node to divide working conditions to operate, the operation is called as a low-temperature mode and a high-temperature mode for short, a spraying control system stops spraying operation in the low-temperature mode, an evaporation heat exchange part of the dry-wet combination operates as an air cooling section, and due to the fact that the heat transfer efficiency is extremely low, part or all of the evaporation heat exchange part can be short-circuited through an air inlet control system to reduce pneumatic resistance and save electricity.

When ambient temperature is higher than the set temperature value, the control system that sprays sets up in the region of spraying above the evaporation zone through packet control, regulate and control evaporation zone load and save water, this is the high temperature mode, high to certain extent when ambient temperature, air cooling section heat transfer efficiency drops to when can neglecting, air inlet control system also can be with the short circuit of air cooling section, in order to reduce the quiet wind pressure of system, however, as is known, ambient air's temperature and humidity are all changing constantly, if will obtain ideal water conservation effect under the high temperature mode, need the real-time collection of intelligence control system, the processing data, accomplish that the feedback is sensitive, accurate control and control system need frequently move the side just feasible, this has the control degree of difficulty in the practical application link.

At present, the main engineering problems of the dry-wet combined cold water technology are that the real-time reaction and regulation performance of an intelligent control system to the change of environmental meteorological data are poor, and the water saving performance is poor; the problems that the surface of a heat exchange element is easily polluted, blocked, corroded and the like in the air cooling section, which influence the stability and the service life of the equipment in the heat exchange process are easily caused; the large-scale equipment has no satisfactory solution to the industry, and forms a technical barrier for the popularization and application of the equipment.

The water resource shortage is the basic national condition of China, and the underground water resource which is non-renewable or has a long regeneration period is excessively exploited, so that the sustainable development of national economy is threatened; the annual increase of the water cost is the body-cutting feeling faced by enterprises; the establishment of a water evaluation and assessment system, and the establishment of a water conservation system mechanism are basic policy and policy for future national economic development of China, and are the basic national conditions that we will face. Under the background, from the current development situation of the current water cooling technology and the cognition of users, the technology efficiency is lost, the equipment investment is increased, and the limited water saving index is generally accepted in the industry, so that the technology is a social public opinion environment which is very beneficial to promoting the innovation of the dry-wet combined water cooling technology.

Disclosure of Invention

To the above-mentioned problem that the cold water technique exists is united to tradition futilely wet, this patent application provides a novel dry and wet cooling tower, evaporative condenser, realizes energy-conserving water conservation and improves heat transfer efficiency.

In order to achieve the purpose, the invention adopts the following technical scheme: the method comprises the following steps: the heat exchanger comprises an equipment frame, wherein an upper layer of basic heat exchange units and a lower layer of basic heat exchange units are arranged in the equipment frame, a water collecting tank is arranged at the bottom of the equipment frame, and a fan is arranged at the top of the equipment frame; each layer of basic heat exchange units is provided with two opposite groups, and each layer of basic heat exchange units comprises: the device comprises a fin heat exchanger and a spray heat exchanger, wherein the fin heat exchanger is arranged close to the side wall of the equipment frame, and the spray heat exchanger is arranged on one side of the fin heat exchanger, which is far away from the side wall of the equipment frame; and a spray header connected with a water collecting tank pipeline is arranged above each layer of basic heat exchange units.

Preferably, the fin heat exchanger adopts a U-shaped header, and a condensing agent inlet and a condensing agent outlet are formed in the fin heat exchanger.

Preferably, a shutter is further arranged between the fin heat exchanger and the spray heat exchanger.

Preferably, the spray heat exchanger adopts an S-shaped header.

Preferably, a dehydrator is further arranged, and the dehydrator is obliquely arranged on one side, away from the fin heat exchanger, of the spray heat exchanger.

Preferably, the spray header is connected with the water collecting tank through a spray pipe, and the spray pipe is provided with a spray pump.

Preferably, two groups of spray headers on the upper layer and the lower layer share one spray pipe, and two groups of spray headers on the same layer adopt different spray pipes to convey circulating water.

Preferably, a water distribution plate is further arranged above the basic heat exchange unit, and the water distribution plate is located below the spray header and above the basic heat exchange unit.

By adopting the method for repeatedly collecting and distributing the water, the total water spraying circulation volume of the device is only 1-2 times of the water spraying circulation volume of the dry-wet combined heat exchange basic unit, the required lift of the water spraying circulation system is not obviously changed, and the electricity-saving effect is obvious.

Ambient air flows to the evaporation section from the air cooling section so as to improve the temperature of air entering the evaporation section, the relative humidity index of the air is reduced, the relative volatility of water at the air-water interface is improved, the mass transfer concentration is promoted to be enhanced, and the heat and mass transfer process which is based on the phase change evaporation effect and occurs on the surface of a water film on the wall of the heat exchange pipe is enhanced under the condition of effective heat supply. The air enthalpy moisture data indicates: for wet air, the higher the basic temperature of the air under the same temperature difference, the larger the enthalpy difference, so the air is preheated by the air cooling section to improve the heat and mass transfer performance of the air in the evaporation section, and more ideal heat transfer data and indexes can be obtained, particularly the medium-temperature mode characteristic is obvious in the low-temperature meteorological environment; secondly, the ambient air and the air cooling section have a preferential heat exchange process scheme, and the air cooling section can obtain a higher average heat exchange temperature difference than the traditional technical process, so that the heat flux of a unit heat exchange area is improved.

The invention has the beneficial effects that: outside air passes through fin heat exchanger, shutter, spray heat exchanger in proper order, has combined dry cooling to wet cold cooling, and the air passes through the wing section earlier and passes through the shower section again, avoids the scale deposit and has improved the air temperature who gets into the shower section for the evaporation efficiency of shower section, and adopt upper and lower range upon range of formula heat exchange, reduce area, the cooperation is received water distribution many times, realizes energy-conserving water conservation.

Drawings

FIG. 1 is a schematic structural view of the present invention;

FIG. 2 is a schematic view of the internal structure of FIG. 1;

in the figure: 1. a fan; 2. a finned heat exchanger; 3. a blind window; 4. spraying a heat exchanger; 5. a water collection tank; 6. a spray pump; 7. a spray pipe; 8. an equipment frame; 9. and a dehydrator.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings.

As shown in fig. 1 to fig. 2, the present invention provides a novel dry-wet cooling tower and evaporative condenser, which comprises: the device comprises an equipment frame, wherein an upper layer of basic heat exchange unit and a lower layer of basic heat exchange unit for dry-wet combined exchange are arranged in the equipment frame, the bottom of the equipment frame is a water collecting tank, and the top of the equipment frame is provided with a fan; each layer of basic heat exchange units is provided with two opposite groups, and each layer of basic heat exchange units comprises: the device comprises a fin heat exchanger and a spray heat exchanger, wherein the fin heat exchanger is arranged close to the side wall of the equipment frame and is positioned at an air inlet, and the spray heat exchanger is arranged on one side of the fin heat exchanger, which is far away from the side wall of the equipment frame; and a spray header connected with a water collecting tank pipeline is arranged above each layer of basic heat exchange units.

Preferably, the spray heat exchanger adopts smooth pipes and is distributed by adopting an S-shaped header.

Preferably, the device is further provided with a dehydrator, wherein the dehydrator is obliquely arranged on one side of the spraying heat exchanger, which is far away from the fin heat exchanger, is positioned on the downwind side of the spraying heat exchanger and is used for recovering water mist carried into air.

Preferably, a water distribution disc is arranged above the basic heat exchange unit, the water distribution disc is positioned below the spray header and above the basic heat exchange unit, water flow of the water distribution disc directly falls on the upper surface of the heat exchange tube to form a water film, the film forming property is good, the surface of the water film is quickly updated, the evaporation effect on the surface of the heat exchange tube can be effectively enhanced, and the heat transfer coefficient of an evaporation section is improved; the technical defects of the traditional spraying and water distribution mode can be effectively overcome; the water distribution disc is matched with a spraying system to realize repeated water collecting and distributing operations, so that the evaporation heat exchange elements can obtain stable water film distribution to effectively control and correct the transverse drift of the sprayed water, the total sprayed water circulation amount of the device is only 1-2 times of the sprayed water circulation amount of the dry-wet combined heat exchange basic unit, the required lift of the sprayed water circulation system is not obviously changed, and the electricity-saving effect is obvious.

The above-described embodiments are merely illustrative of the principles and utilities of the present patent application and are not intended to limit the present patent application. Modifications and variations can be made to the above-described embodiments by those skilled in the art without departing from the spirit and scope of this patent application. Accordingly, it is intended that all equivalent modifications or changes which can be made by those skilled in the art without departing from the spirit and technical concepts disclosed in the present application shall be covered by the claims of this patent application.

Claims

1. A novel dry and wet cooling tower and evaporative condenser comprises: the heat exchanger comprises an equipment frame, wherein an upper layer of basic heat exchange units and a lower layer of basic heat exchange units are arranged in the equipment frame, a water collecting tank is arranged at the bottom of the equipment frame, and a fan is arranged at the top of the equipment frame; each layer of basic heat exchange units is provided with two opposite groups, and each layer of basic heat exchange units comprises: the device comprises a fin heat exchanger and a spray heat exchanger, wherein the fin heat exchanger is arranged close to the side wall of the equipment frame, and the spray heat exchanger is arranged on one side of the fin heat exchanger, which is far away from the side wall of the equipment frame; and a spray header connected with a water collecting tank pipeline is arranged above each layer of basic heat exchange units.

2. The novel dry and wet cooling tower and evaporative condenser as claimed in claim 1, wherein: the fin heat exchanger adopts a U-shaped collecting pipe, and a condensing agent inlet and a condensing agent outlet are formed in the fin heat exchanger.

3. The novel dry and wet cooling tower and evaporative condenser as claimed in claim 1, wherein: a shutter is also arranged between the fin heat exchanger and the spray heat exchanger.

4. The novel dry and wet cooling tower and evaporative condenser as claimed in claim 1, wherein: the spraying heat exchanger adopts an S-shaped collecting pipe.

5. The novel dry and wet cooling tower and evaporative condenser as claimed in claim 1, wherein: the spraying heat exchanger is also provided with a dehydrator, and the dehydrator is obliquely arranged on one side of the spraying heat exchanger, which is far away from the fin heat exchanger.

6. The novel dry and wet cooling tower and evaporative condenser as claimed in claim 1, wherein: the spray header is connected with a water collecting tank through a spray pipe, and a spray pump is arranged on the spray pipe.

7. The novel dry and wet cooling tower and evaporative condenser as claimed in claim 3, wherein: two groups of spray headers on the upper layer and the lower layer share one spray pipe, and two groups of spray headers on the same layer adopt different spray pipes to convey circulating water.

8. The novel dry and wet cooling tower and evaporative condenser as claimed in claim 7, wherein: and a water distribution disc is also arranged above the basic heat exchange unit, is positioned below the spray header and is positioned above the basic heat exchange unit.