Counter-flow indirect dew point evaporative cooler

Abstract

A non-straight plate type heat exchanger is adopted, the reverse flow type evaporative cooler is composed of multiple layers of non-straight plates, dry channels and wet channels B are alternately arranged between the adjacent non-straight plates, the dry channels are divided into the dry channels A and the dry channels C, and the dry channels A and the dry channels C are adjacent to the wet channels B; the dry channel A is used for generating working air and inputting the working air into the wet channels B on the two sides of the dry channel A; and the dry channel C is used for generating product air. The non-straight plate evaporative cooler structure in the design is beneficial to enhancing gas-water disturbance and mixing and enhancing heat transfer, so that gas flow can be better controlled, and better cooling performance is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of evaporative cooling, and in particular to an evaporative cooler adopting a countercurrent indirect dew-point evaporative cooling technology. Background Art

[0002] As people's living standards improve, the demand for comfortable air conditioners continues to increase. As energy-consuming products, the supply of electricity will be a severe test. In 2005, the average number of air conditioners per 100 households in urban areas in my country was about 80.7, and the number of air conditioners in 170 million households reached about 137 million. According to data from the National Bureau of Statistics, in 2023, there will be 145.9 air conditioners per 100 households in China. As the power load of air conditioners has increased sharply year by year, the energy consumption of air conditioners has accounted for about 15% of the national power consumption. Even in the peak period of summer power consumption, the power load of air conditioners is as high as about 40% of the overall power load in cities and towns. Once summer comes, the temperature rises sharply and it is put into operation, which will inevitably bring serious power peak and valley problems.

[0003] In order to reduce the energy consumption of traditional air conditioning systems, the serious peak and valley problems of electricity, and the emission of greenhouse gases, researchers have proposed several alternative technologies, such as absorption / adsorption chillers and evaporative coolers. Among these methods, evaporative coolers are considered to be the most suitable alternative because of their high energy efficiency, low capital and operating costs, easy installation and maintenance, no greenhouse gas emissions, and no heat discharge to the environment.

[0004] The working principle of the evaporative cooler is to use the huge latent heat of evaporation of water, which means to reduce the process air temperature by absorbing heat through the evaporation of water. The indirect dew-point evaporative cooler invented by Soviet scientist Maisotsenko in 1976 is considered an excellent choice among evaporative coolers because it can cool the process air below the wet-bulb temperature and close to the dew point temperature without increasing the humidity of the product air.

[0005] In an indirect dew point evaporative cooler, process air 100 is cooled in a dry channel 101, as shown in the attached Figure 1 (a). A portion of the process air 100 cooled in the dry channel 101 is transferred to the wet channel 103 to become the working air 104 (referred to as the return air in this application) to drive the evaporation of water. Since the working air 104 is cooled before contacting the water, the cooling potential becomes higher. Therefore, the working air 104 in the wet channel 103 can reach the dew point temperature and can cool the process air 100 in the dry channel 101 to below the wet bulb temperature, as shown in FIG. Figure 1 (b) is shown in the enthalpy-psychrometric diagram. This technology was known as "M cycle cooling" at the time.

[0006] Chinese patent CN202310916991.7-A countercurrent indirect dew-point evaporative cooler discloses a countercurrent indirect dew-point evaporative cooler, including a shell, a heat exchanger arranged in the shell, and a fan arranged on the shell; the heat exchanger is composed of multiple layers of parallel separation plates, and the adjacent separation plates are alternately arranged dry channels and wet channels, wherein the dry channel is divided into dry channel A and dry channel C, which are respectively located on both sides of the wet channel; dry channel A is used to generate working air and input it into the wet channels on both sides of dry channel A; dry channel C is used to generate product air. Its working principle is as shown in the attached figure. Figure 2 As shown in (a), the two sides of the wet channel B are dry channels A and dry channels C, which are arranged alternately. Among them, process air 201 is introduced into the dry channel A on the side adjacent to the wet channel B, and the dry channel outputs working air 203. The working air 203 enters the wet channels on both sides respectively, and serves as exhaust air 203 after passing through the wet channels. Process air 204 is introduced into the dry channel C on the other side adjacent to the wet channel, and the dry channel outputs product air 205. The working air 202 drives the moisture in the wet channel B to evaporate to cool the process air 201 in the dry channel A and the process air 204 in the dry channel C. Since the working air 202 is pre-cooled before entering the wet channel, its cooling potential is increased. Based on this, the process air can be cooled to a temperature lower than the wet bulb temperature of the working air or even close to its dew point temperature. The changes in air temperature and humidity are shown in the attached figure. Figure 2 (b) Enthalpy-humidity diagram. Compared with compression refrigeration air conditioners, this technology has been experimentally verified and has significant energy-saving effects. However, this technical solution also has certain problems: the air in dry channel A and dry channel C that passes through parallel partitions exchanges heat with the wet air in wet channel B that passes through parallel partitions, the middle part of the air flow in wet channel B is not easy to exchange heat through the partition, and the air and water in wet channel B are not easy to mix evenly, so there is room for improvement.

[0007] Therefore, how to select a suitable evaporative cooler structure to enhance the cooling effect is worthy of in-depth study. Summary of the invention

[0008] The purpose of the present invention is to solve the above-mentioned problems and to provide a new evaporative cooler, which adopts a non-straight plate such as a curved plate structure to enhance the disturbance and mixing of air and water in the wet channel, and enhance the heat exchange effect between the cold and wet air in the wet channel and the air in the dry channel. The effective heat transfer enhancement measures will reduce the heat transfer area and thus reduce the resistance loss, thereby compensating for the resistance loss increased by the non-straight plate structure. In this application, the working air and the process air are completely separated. The two independent airflows can allow more air to be selected as working air, thereby better controlling the airflow and having better cooling performance. This also allows the cooler to be used in more situations where the process air needs to remain unchanged.

[0009] A countercurrent indirect dew-point evaporative cooler, comprising: The housing 210, the heat exchanger 200, the fan and the water distribution components arranged in the housing, The heat exchanger 200 is composed of multiple layers of non-straight plates 20 such as curved plates. Dry channels and wet channels B are alternately arranged between adjacent non-straight plates 20. The distances between adjacent non-straight plates 20 are equal or unequal. The non-straight plates 20 are manufactured by stamping and other processes. The transition of the non-straight plates 20 along the flow channel direction is rounded or smooth, thereby reducing resistance. The dry channel is divided into a dry channel A and a dry channel C, which are adjacent to the wet channel B; the dry channel A is used to generate working air 22 and input it into the wet channels B on both sides of the dry channel A; the dry channel C is used to generate product air 25, as shown in the attached Figure 3 shown.

[0010] An air gap is provided between the output end of the dry channel A and the wet channels B on both sides of the dry channel A, and the working air 22 is input into the wet channel B through the air gap.

[0011] The fans are arranged in one or more directions toward the input ends of the wet channel process air 21 and the dry channel process air 24. Figure 4 One arrangement is shown.

[0012] The heat exchanger 200 is provided with a water distribution component, and adopts a lower water distribution method or an upper water distribution method: when the lower water distribution method is adopted, the wet surface of the lower part of the non-straight plate 20 located in the wet channel B extends into the water distribution component, and the wet surface of the non-straight plate 20 extends into the water distribution component by using capillary material; when the upper water distribution method is adopted, the water distribution component is located at the upper part of the wet channel B, and the water in the water distribution component falls into the wet channel B, or the water distribution component is located at the upper part of the dry channel A and the dry channel C, and the water in the water distribution component flows into the wet channel B along the non-straight plate 20, and a water receiver is provided at the lower part of the wet channel B to collect the fallen water and discharge it to a safe place.

[0013] Preferably, the air inlet of the fan is provided with a protective cover to prevent leaves, animals, etc. from entering, or human hands from accidentally entering and causing injuries.

[0014] Preferably, the input ends of the wet channel process air 21 and the dry channel process air 24 of the dry channel A and the dry channel C are both equipped with fans.

[0015] The dry channel C and the adjacent wet channel B are isolated from each other.

[0016] The wet channel process air 21 inlet of the dry channel A and the exhaust air 23 outlet of the wet channel B are symmetrically distributed on both sides of the non-straight plate 20 .

[0017] Preferably, the channel thicknesses of the wet channel B, the dry channel A and the dry channel C are expressed as WB, WA and WC respectively, and the relationship between them is expressed as: WA:WC=0.65-1.5, WA:WB=1-3.

[0018] Preferably, the channel thicknesses of the wet channel B, the dry channel A and the dry channel C are expressed as WB, WA and WC respectively, where WA:WC=1 and WA:WB=2.

[0019] Referring to CN202310916991.7-A countercurrent indirect dew point evaporative cooler, combined with the attached Figure 3 , Attachment Figure 4 The present invention provides a countercurrent indirect dew-point evaporative cooler with a lower water distribution component and specifically describes it. Its structure and working principle are as follows: The heat exchanger 200 is composed of a plurality of alternately arranged dry channels and wet channels, such as Figure 3 As shown, the two sides of the wet channel B are respectively the dry channel A and the dry channel C, which are arranged alternately. Among them, the wet channel process air 21 is introduced into the dry channel A on one side adjacent to the wet channel B, and the dry channel outputs the working air 22. The working air 22 enters the wet channels on both sides respectively, and is used as the exhaust air 23 after passing through the wet channels. The dry channel process air 24 is introduced into the dry channel C on the other side adjacent to the wet channel, and the dry channel outputs the product air 25; The working air 22 is mixed with the water with a lower temperature in the wet channel B, and the liquid water evaporates to cool the wet channel process air 21 in the dry channel A and the dry channel process air 24 in the dry channel C; since the working air 22 is pre-cooled before entering the wet channel, its cooling potential is increased. Based on this, the dry channel process air 24 can be cooled to a temperature lower than the wet bulb temperature of the working air or even close to its dew point temperature; A shell 210 is disposed outside the heat exchanger 200, and the shell 210 is used to wrap and support the heat exchanger 200. At least two fans are disposed on the shell 210, namely, fan No. 1 211-a and fan No. 2 211-b, fan No. 1 211-a is arranged toward the wet channel process air 21, and fan No. 2 211-b is arranged toward the dry channel process air 24, and air from the environment can be respectively sent into the dry channel A and the dry channel C as process air.

[0020] A water distribution component is also provided on the shell 210, and at least two water distribution components are provided, namely water distribution component No. 1 212-a and water distribution component No. 212-b, which are located on opposite sides of the heat exchanger 200; the two ends of the wet surface of the non-straight plate 20 extend into the water distribution component No. 1 212-a and the water distribution component No. 2 212-b respectively, and the wet surface uses capillary material to absorb water to maintain the wetness of the wet surface of the non-straight plate 20.

[0021] The housing 210 and the water distribution components and the fan on the housing 210 can adjust their positions according to the actual application scenario.

[0022] Preferably, the power supply, air duct, air filter, support frame, electric control system, etc. are installed in combination with actual needs, and matched with reference to or according to the mature technology in the well-known traditional evaporative cooler and air conditioner.

[0023] Compared with the prior art, the present invention has the following advantages: 1. Compared with the existing indirect dew-point evaporative cooling technology (CN202310916991.7-a countercurrent indirect dew-point evaporative cooler), the non-straight plate structure of the present invention enhances the disturbance and mixing of gas and water, and enhances the heat transfer effect between air and cold wet air in the dry and wet channels; when the upper water distribution method is adopted, the water is evenly distributed, eliminating the problem of uneven water distribution in the upper and lower parts caused by gravity when the capillary material is distributed; 2. Compared with the existing water-spraying air coolers using direct evaporative cooler technology (such as CN202311464379.7-a water curtain air cooler with a uniform water distribution device, CN202320571950.4-an energy-saving air cooler, etc.), the present invention uses fresh air cooling technology, which has better effects: using the same natural cold source such as tap water, the cooling temperature is lower and the indoor air humidity and freshness can be maintained; the traditional air cooler technology is a simple indoor circulation method, and the indoor air humidity is getting closer and closer to 100%, and doors and windows need to be opened for ventilation, which is easy to produce a stuffy feeling, and the high humidity environment is prone to bacteria and mold; 3. Compared with the existing gas compression air conditioning technology, the present invention does not require a high-pressure compressor, does not require fluorine-containing refrigerants or their substitutes, has no heat island effect, uses fresh air for cooling, saves energy and electricity, and has low operating costs; 4. Compared with the existing absorption air conditioning or adsorption air conditioning technology, the system of the present invention is simple and reliable, easy to install, repair and maintain, and has low operating costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 In the figure, (a) shows the working principle of the M cycle indirect evaporative cooler. (b) shows the change of air temperature and humidity ratio during the M cycle cooling process shown in (a).

[0025] Figure 2 It is CN202310916991.7-Working principle and enthalpy-humidity diagram of a countercurrent indirect dew-point evaporative cooler.

[0026] Figure 3 It is a schematic diagram of the working principle of the present invention.

[0027] Figure 3Middle: 20- non-straight plate, 21- wet channel process air, 22- working air, 23- exhaust air, 24- dry channel process air, 25- product air (i.e. cooling air), the two sides of wet channel B are dry channel A and dry channel C respectively.

[0028] Figure 4 The present invention is a schematic diagram of the external structure of a bottom water distribution type countercurrent indirect dew point evaporative cooler.

[0029] Figure 4 In the figure: 200-heat exchanger, 210-shell, 211-a-fan No. 1, 211-b-fan No. 2, 212-a-water distribution component No. 1, 212-b-water distribution component No. 2. DETAILED DESCRIPTION

[0030] The following is combined with Figure 3 , Attachment Figure 4 The present invention is further described in detail with reference to the accompanying drawings and specific examples.

[0031] Embodiment 1: A countercurrent indirect dew-point evaporative cooler, comprising: The housing 210, the heat exchanger 200, the fan and the water distribution components arranged in the housing, The heat exchanger 200 is composed of multiple layers of non-flat plates 20 such as curved plates, and dry channels and wet channels B are alternately arranged between adjacent non-flat plates 20. The distances between adjacent non-flat plates 20 are equal. The non-flat plates 20 are manufactured using a stamping process, and the non-flat plates 20 have a smooth or smooth transition along the flow direction, wherein the dry channel is divided into a dry channel A and a dry channel C, which are adjacent to the wet channel B; the dry channel A is used to generate working air 22 and input it into the wet channels B on both sides of the dry channel A; the dry channel C is used to generate product air 25.

[0032] An air gap is provided between the output end of the dry channel A and the wet channels B on both sides of the dry channel A, and the working air 22 is input into the wet channels through the air gap.

[0033] The fans are arranged in two towards the process air input end, as shown in the attached Figure 4 shown.

[0034] The heat exchanger 200 is provided with a water distribution component, which adopts a lower water distribution method: the wet surface of the lower part of the non-straight plate 20 located in the wet channel B extends into the water distribution component, and the wet surface of the non-straight plate 20 extends into the water distribution component by using capillary material.

[0035] Preferably, the air inlet of the fan is provided with a protective cover to prevent leaves, animals, etc. from entering, or human hands from accidentally entering and causing injuries.

[0036] The dry channel C and the adjacent wet channel B are isolated from each other.

[0037] The wet channel process air 21 inlet of the dry channel A and the exhaust air 23 outlet of the wet channel B are symmetrically distributed on both sides of the non-straight plate 20 .

[0038] Preferably, the channel thicknesses of the wet channel B, the dry channel A and the dry channel C are expressed as WB, WA and WC respectively, and the relationship between them is expressed as: WA:WC=0.65-1.5, WA:WB=1-3.

[0039] Preferably, the channel thicknesses of the wet channel B, the dry channel A and the dry channel C are expressed as WB, WA and WC respectively, where WA:WC=1 and WA:WB=2.

[0040] Referring to CN202310916991.7-A countercurrent indirect dew point evaporative cooler, combined with the attached Figure 3 , Attachment Figure 4 The present invention provides a countercurrent indirect dew-point evaporative cooler with a lower water distribution component and specifically describes it. Its structure and working principle are as follows: The heat exchanger 200 is composed of a plurality of alternately arranged dry channels and wet channels B, such as Figure 3 As shown, the two sides of the wet channel B are respectively the dry channel A and the dry channel C, which are arranged alternately. Among them, the wet channel process air 21 is introduced into the dry channel A on one side adjacent to the wet channel B, and the dry channel A outputs the working air 22. The working air 22 enters the wet channels B on both sides respectively, and is used as the exhaust air 23 after passing through the wet channel B. The dry channel C on the other side adjacent to the wet channel B is introduced into the dry channel process air 24, and the dry channel outputs the product air 25; The working air 22 is mixed with the water with a lower temperature in the wet channel B, and the liquid water evaporates to cool the wet channel process air 21 in the dry channel A and the dry channel process air 24 in the dry channel C; since the working air 22 is pre-cooled before entering the wet channel B, its cooling potential is increased. Based on this, the dry channel process air 24 can be cooled to a temperature lower than the wet bulb temperature of the working air or even close to its dew point temperature; A shell 210 is provided outside the heat exchanger 200, and the shell 210 is used to wrap and support the heat exchanger 200. Two fans are provided on the shell 210, namely, fan No. 1 211-a and fan No. 2 211-b. Fan No. 1 211-a is arranged toward the wet channel process air 21, and fan No. 2 211-b is arranged toward the dry channel process air 24, and air from the environment can be pumped into the dry channel A and the dry channel C as process air.

[0041] A water distribution component is also provided on the shell 210, and two water distribution components are provided, namely water distribution component No. 1 212-a and water distribution component No. 212-b, which are located on opposite sides of the heat exchanger 200; the two ends of the wet surface of the non-straight plate 20 extend into the water distribution component No. 1 212-a and the water distribution component No. 2 212-b respectively, and the wet surface uses capillary material to absorb water to maintain the wetness of the wet surface of the non-straight plate 20.

[0042] The housing 210 and the water distribution components and the fan on the housing 210 can adjust their positions according to the actual application scenario.

[0043] Preferably, the power supply, air duct, air filter, support frame, electric control system, etc. are installed in combination with actual needs, and matched with reference to or according to the mature technology in the well-known traditional evaporative cooler and air conditioner.

[0044] Although the present invention has been disclosed as above with preferred embodiments, they are not intended to limit the present invention. Anyone familiar with the art can make various changes or modifications without departing from the spirit and scope of the present invention, which also belong to the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the definition of the claims of this application.

Claims

1. A countercurrent indirect dew-point evaporative cooler, characterized in that: include: a housing (210), a heat exchanger (200) disposed in the housing, a fan, and a water distribution component, The heat exchanger (200) is composed of a plurality of non-straight plates (20), wherein dry channels and wet channels B are alternately arranged between adjacent non-straight plates (20), wherein the dry channels are divided into dry channels A and dry channels C, and are adjacent to the wet channels B; the dry channels A are used to generate working air (22) and input the working air into the wet channels B on both sides of the dry channels A; the dry channels C are used to generate product air (25), The fan provided on the housing (210) is arranged toward the input ends of the wet channel process air (21) and the dry channel process air (24).

2. The countercurrent indirect dew-point evaporative cooler according to claim 1, characterized in that: An air gap is provided between the output end of the dry channel A and the wet channels B on both sides of the dry channel A, and working air (22) is input into the wet channel B through the air gap.

3. The countercurrent indirect dew-point evaporative cooler according to claim 1, characterized in that: The heat exchanger (200) is provided with a water distribution component, which adopts a lower water distribution method or an upper water distribution method.

4. The counter-current indirect dew-point evaporative cooler according to claim 3, characterized in that: When the lower water distribution method is adopted, the wet surface of the lower part of the non-straight plate (20) located in the wet channel B extends into the water distribution component, and the wet surface of the non-straight plate (20) extends into the water distribution component using capillary material.

5. The counter-current indirect dew-point evaporative cooler according to claim 3, characterized in that: When the upper water distribution method is adopted, the water distribution component is located at the upper part of the wet channel B, and the water in the water distribution component falls into the wet channel B; or the water distribution component is located at the upper part of the dry channel A and the dry channel C, and the water in the water distribution component flows into the wet channel B along the non-straight plate (20), and the lower part of the wet channel B is provided with a water receiver.

6. The counter-current indirect dew-point evaporative cooler according to claim 1, characterized in that: Between the adjacent non-straight plates (20) are dry channels and wet channels B that are alternately arranged, and the distances between the adjacent non-straight plates (20) are equal or unequal.

7. The counter-current indirect dew-point evaporative cooler according to claim 1, characterized in that: The wet channel process air (21) inlet of the dry channel A and the exhaust air (23) outlet of the wet channel B are symmetrically distributed on both sides of the non-straight plate (20).

8. The counter-current indirect dew-point evaporative cooler according to claim 1, characterized in that: The channel thicknesses of the wet channel B, the dry channel A and the dry channel C are expressed as WB, WA and WC respectively, and the relationship between them is expressed as: WA:WC=0.65-1.5, WA:WB=1-3.

9. The counter-current indirect dew-point evaporative cooler according to claim 1, characterized in that: The channel thicknesses of the wet channel B, the dry channel A and the dry channel C are represented as WB, WA and WC respectively, where WA:WC=1 and WA:WB=2.

10. The counter-current indirect dew-point evaporative cooler according to claim 1, characterized in that: The dry channel C and the adjacent wet channel B are isolated from each other.

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