Evaporation heat exchanger, control method and air conditioner

Abstract

The invention relates to an evaporation heat exchanger, a control method and an air conditioner, the evaporation heat exchanger adopts a vertical tube type heat exchanger and water film type dust collector water distribution technology, the M-Cycle principle is combined, and the efficient heat transfer effect is achieved through evaporation heat exchange of water. The evaporative heat exchanger and the air conditioning technology are really free of an outdoor unit, free of a heat island effect, free of fluorine-containing refrigerants or substitutes of the fluorine-containing refrigerants and capable of supplying cold or heat through fresh air, installation and maintenance are convenient, the operation cost is low, and expected social and economic benefits are remarkable.

Description

Technical Field

[0001] The present invention relates to the technical field of evaporative heat exchange, and in particular to an evaporative heat exchanger, a control method and an air conditioner using an indirect dew-point evaporative heat exchange technology. Background Art

[0002] As people's living standards improve, the demand for comfortable air conditioners continues to increase. As energy-consuming products, they will pose a severe test to the supply of electricity. Once summer comes and the temperature rises sharply, the operation of air conditioners will inevitably bring about serious peak and valley problems in electricity.

[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 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 psychrometric diagram. This technology was known as "M cycle cooling" at the time.

[0006] The basic principle of M-Cycle is to use the latent heat of evaporation of water to reduce the air temperature. In M-Cycle, the air is first pre-cooled, and then the air temperature is further reduced by direct contact with water, using the heat absorbed by the evaporation of water. This process can cool the air to a temperature close to the dew point without increasing the humidity of the air.

[0007] Key features of the M-Cycle include: 1. Energy capture: Capture energy from the air through the latent heat of water evaporation.

[0008] 2. Dew point evaporative cooling: It can achieve a cooling effect below the wet bulb temperature, which is unattainable by traditional evaporative cooling.

[0009] 3. Heat and mass exchange: Through the special heat exchanger design, efficient heat and mass transfer is achieved, thereby improving the energy efficiency of the system.

[0010] 4. Environmental adaptability: The M-Cycle system can operate efficiently under different ambient humidity conditions, especially in areas with low humidity.

[0011] 5. Energy saving potential: Compared with traditional compression refrigeration air conditioning systems, M-Cycle can more efficiently utilize the latent heat of water, reportedly increasing efficiency by 10 times.

[0012] In general, the M-Cycle is an innovative thermodynamic cycle that achieves efficient heat transfer by utilizing the latent heat of evaporation of water, while having the potential to save energy and reduce environmental pollution.

[0013] Therefore, it is worthy of in-depth study how to select a suitable evaporative heat exchanger structure to achieve energy-saving cooling in summer and energy-saving heating in winter, supply fresh air at an appropriate temperature without seasonal restrictions, have no outdoor unit, and have beautiful equipment layout and convenient maintenance, thereby expanding the application scope of the M-Cycle principle. Summary of the invention

[0014] The purpose of the present invention is to solve the above problems and provide a vertical evaporative heat exchanger, a control method and an air conditioner. The design of the evaporative heat exchanger refers to the basic principles of conventional shell-and-tube heat exchangers and water film dust collectors. The evaporative heat exchanger includes a shell, a tube sheet, a tube bundle (composed of evaporative heat exchange tubes), a baffle, a head, a pipe, etc. The shell side of the evaporative heat exchanger carries the input primary air (outdoor air), and the tube side carries the return air. The water is sprayed or diffused into the inner wall of the tube, and the air passes from bottom to top. The inside of the tube is similar to a miniature water film dust collector for wet heat exchange. The water film is mixed with the air and undergoes an evaporative heat exchange process with the air in the shell side. With this structure, the resistance of the shell side will increase a little, but effective heat transfer enhancement measures can be adopted, which will reduce the heat transfer area and thus reduce the resistance loss. It can optimize and efficiently provide cooling or heating. For example, when heating is needed in winter, hot water can be used to humidify the input air and the return air can be heated and heated to adjust the temperature and humidity of the heating air to a suitable range.

[0015] An evaporative heat exchanger (such as Figure 2As shown in FIG. 1 ), the vertical evaporative heat exchanger includes a shell, a head, a tube sheet, a tube bundle (composed of multiple evaporative heat exchange tubes), and an air inlet and outlet pipe. Primary air (i.e., outdoor fresh air) enters the shell side of the evaporative heat exchanger through a blower 2, passes horizontally through the gaps between the evaporative heat exchange tubes, and contacts the evaporative heat exchange tubes for heat exchange, and then becomes indoor working air 8 for output; The evaporative heat exchanger 3 is provided with an air inlet and a water supply 9 inlet. A part of the air diverted from the indoor working air 8 enters the evaporative heat exchange tube of the evaporative heat exchanger tube through the secondary air pipeline (i.e., the return air pipeline) through the air inlet, and performs heat and moisture exchange with the water supply 9 sent to the evaporative heat exchange tube port at the upper part of the evaporative heat exchanger from bottom to top, and then performs heat exchange with the primary air outside the evaporative heat exchange tube 5, and is led out from the upper part of the evaporative heat exchanger to become exhaust air 13 and discharged to the outside. The feed water that exchanges heat and moisture with the reflux gas falls into the gas-water separation chamber 16 of the evaporative heat exchanger 3 and undergoes gas-water separation, and the separated water is discharged through the drain regulating valve 18.

[0016] In summer, the water supply of the evaporative heat exchanger 3 uses tap water, groundwater or chilled water as a natural cold source. At this time, the indoor working air 8 is cooling air, and the evaporative heat exchanger 3 is actually an evaporative cooler; in winter, the water supply of the evaporative heat exchanger 3 uses hot water, and the hot water temperature is generally higher than 40°C. The hot water comes from a solar water heater, a gas water heater or electric heating, etc. At this time, a part of the water diverted from the water supply 9 is mixed with the primary air through the humidification pipeline 11 and the humidification regulating valve 12 for heating and humidification, and the humidity of the indoor working air 8 is adjusted to be within the comfortable range for the human body, for example, the humidity is maintained in the range of 40% to 60%. At this time, the evaporative heat exchanger is actually a heating heater, and the indoor working air 8 is heating air.

[0017] When the load required by the application scenario of the evaporative heat exchanger 3 is a cooling load, such as a data center, the evaporative heat exchanger 3 essentially operates in an evaporative cooler mode.

[0018] Preferably, the evaporative heat exchanger is provided with a baffle 6 to ensure that the primary air entering the evaporative heat exchanger 3 is fully heat exchanged and does not cause heat deviation.

[0019] Preferably, the evaporative heat exchanger 3 adopts a vertical cylindrical structure, which is aesthetically pleasing and convenient for equipment piping, installation, repair and maintenance.

[0020] The evaporation heat exchange tube 5 is a hollow round tube or a special-shaped tube, wherein the special-shaped tube is a hollow non-circular tube. The material of the evaporation heat exchange tube is hydrophilic aluminum foil, aluminum-magnesium alloy or stainless steel.

[0021] Preferably, the evaporation heat exchanger 3 adopts a vertical cylindrical structure, and the evaporation heat exchange tube 5 adopts a spiral groove tube. Figure 3 shown.

[0022] Preferably, the wet air channel of the evaporative heat exchange tube 5 adopts the method of overflow water entering the inner wall of the wet air channel pipe, which refers to the principle of overflow water entering the inner wall of the water film dust collector in the boiler of a small power station. The water distribution is relatively uniform and reliable. At this time, the evaporative heat exchange tube 5 is essentially a miniature water film water distributor.

[0023] Preferably, the water inlet end of the evaporation heat exchange tube 5 can be provided with an effective water guide cavity, such as a symmetrical circular hole, a U-shaped hole or other effective water introduction hole, so as to distribute water into the evaporation heat exchange tube smoothly and effectively.

[0024] Preferably, a water retaining plate 20 is provided on the upper portion of the evaporative heat exchanger 3 to prevent the exhaust air 3 from bringing out liquid water.

[0025] The evaporative heat exchanger 3 is provided with necessary sewage discharge, cleaning and maintenance ports.

[0026] A dehumidifier 25 is provided: primary air passes through the blower 2, the evaporative heat exchanger 3 and the dehumidifier 25 to become indoor working air 8.

[0027] The dehumidifier 25 uses air solution dehumidification, rotary dehumidification, membrane dehumidification or coupled dehumidification technology to adjust the humidity of the cooling air, and adopts one or two parallel operation modes to maintain the indoor air humidity within the human comfort range (for example, the humidity is controlled at 40% to 60%).

[0028] Preferably, an indoor air circulation pipeline 23 is provided: the indoor air is mixed with the primary air through the indoor air circulation pipeline 23, enters the blower 2 and the evaporative heat exchanger 3, becomes the indoor working air 8 and the exhaust air 13, and while maintaining the indoor air pressure stable, introduces outdoor fresh air as the indoor working air (for cooling or heating), avoiding the need to open doors and windows for ventilation in other operating modes of the air conditioner to maintain the freshness of the indoor air and a certain negative ion content.

[0029] The primary air (outdoor air) entering the blower 2 is filtered and dust-removed by necessary measures, such as configuring a filter.

[0030] An exhaust fan 24 is provided: the return air passes through the secondary air pipeline 15, the evaporative heat exchanger 3, and the exhaust fan 24 to become exhaust air 13 and is discharged.

[0031] The present invention also proposes a method for controlling an evaporative heat exchanger (eg Figure 4 ), which is realized by the evaporative heat exchanger recorded in any of the above technical solutions, and the control method includes: A temperature sensing element is provided at the indoor working air outlet of the evaporative heat exchanger to detect whether the air supply temperature reaches the set value through the temperature sensing element; When the indoor working air temperature does not reach the set value after the evaporative heat exchanger has been running for a period of time, the cooling or heating capacity is increased by increasing the water supply; When the indoor working air temperature still does not reach the set value after increasing the water supply, adjust the blower damper and adjust the primary air intake to make the indoor working air temperature reach the set value.

[0032] The present invention application also proposes an air conditioner, comprising an evaporative heat exchanger recorded in any one of the above technical solutions.

[0033] The present invention can be provided with an indoor air electronic humidity detector to cooperate with the operation adjustment of the evaporative heat exchanger and the air conditioner.

[0034] Pipes, instruments, valves, bypass facilities with regulating functions, etc. not described in this application are matched with reference to or in accordance with the mature technologies in the well-known traditional evaporative heat exchanger and air conditioner processes.

[0035] Parts not mentioned in this application, such as safety accessories, interlocking protection devices and automatic control, are equipped with existing publicly known technologies, that is, existing mature, reliable and reasonable technical measures are applied to this evaporative heat exchanger and air conditioner.

[0036] Compared with the prior art, the present invention has the following advantages: 1. Compared with the existing air conditioning technology using indirect dew-point evaporative coolers (such as CN202110261850.7-an indirect evaporative condensing unit, CN202310916991.7-a countercurrent indirect dew-point evaporative cooler, etc.), the present invention has no outdoor unit, is less affected by outdoor dust, has convenient water distribution, is easy to install, repair and maintain, and can provide heating in winter; 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 and heating technology, which has better effects: for example, in summer, the same natural cold source such as tap water is used, 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, an outdoor unit, or a fluorine-containing refrigerant or its substitute, has no heat island effect, uses fresh air for cooling and heating, saves energy and electricity, and has low operating costs; 4. Compared with the existing absorption air conditioning or adsorption air conditioning technology, the present invention has no outdoor unit, the system is simple and reliable, the installation, maintenance and repair are convenient, and the operating cost is low; 5. Compared with the existing technology, the present invention is a true fresh air cooling and heating air-conditioning technology without outdoor units, heat island effects, fluorine-containing refrigerants or their substitutes. It is easy to install and maintain, with low operating costs. The equipment can be made into a vertical cylindrical structure, which is beautiful and occupies less useful space. It is particularly suitable for use in homes, data centers, schools and other scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] 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).

[0038] Figure 2 The invention discloses an evaporative heat exchanger and an air conditioner process flow diagram.

[0039] Figure 2 In: 1-primary air (outdoor air), 2-blower, 3-evaporative heat exchanger, 3-1-evaporative heat exchanger shell, 4-tube sheet (including upper and lower tube sheets), 5-evaporative heat exchange tube, 6-baffle, 7-air regulating valve, 8-indoor working air, 9-water supply, 10-water supply regulating valve, 11-humidification pipeline, 12-humidification regulating valve, 13-exhaust air (exhausted to the outside), 14-return air regulating valve, 15-secondary air pipeline (i.e. return air pipeline), 16-air-water separation chamber, 17-drain valve, 18-drainage regulating valve, 19-water receiving tray, 20-water baffle, 21-base, 22-adjusting damper, 23-indoor air circulation pipeline, 24-exhaust fan, 25-dehumidifier.

[0040] Figure 3 This is a schematic diagram of the spiral grooved tube structure.

[0041] Figure 4 It is a control flow chart of the evaporative heat exchanger of the present invention. DETAILED DESCRIPTION

[0042] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0043] Embodiment 1: An evaporative heat exchanger (such as Figure 2 As shown in FIG. 1 ), the evaporative heat exchanger adopts a vertical cylindrical structure, including a shell, a head, a tube sheet, a baffle, a tube bundle (composed of multiple evaporative heat exchange tubes), and an air inlet and outlet pipe. The evaporative heat exchange tube adopts a spiral groove tube. The primary air (i.e., outdoor fresh air) enters the shell side of the evaporative heat exchanger through the blower 2, passes horizontally through the gaps between the evaporative heat exchange tubes, and contacts the evaporative heat exchange tubes for heat exchange, and then becomes the indoor working air 8 for output; The evaporative heat exchanger 3 is provided with an air inlet and a water supply 9 inlet. A part of the air diverted from the indoor working air 8 enters the evaporative heat exchange tube of the evaporative heat exchanger tube through the secondary air pipeline (i.e., the return air pipeline) through the air inlet, and performs heat and moisture exchange with the water supply 9 fed into the evaporative heat exchange tube port at the upper part of the evaporative heat exchanger from bottom to top, and then performs heat exchange with the primary air outside the evaporative heat exchange tube 5, and is led out from the upper part of the evaporative heat exchanger, and becomes exhaust air 13 after being pressurized by the exhaust fan 24 and discharged to the outside. The feed water that exchanges heat and moisture with the reflux gas falls into the gas-water separation chamber 16 of the evaporative heat exchanger 3 and undergoes gas-water separation. The separated water is discharged through the drain regulating valve 18 and enters the water receiving tray 19.

[0044] In summer, the water supply of the evaporative heat exchanger 3 uses tap water as a natural cold source. At this time, the indoor working air 8 is cooling air, and the evaporative heat exchanger 3 is actually an evaporative cooler; in winter, the water supply of the evaporative heat exchanger 3 uses hot water, and the hot water temperature is generally higher than 40°C. The hot water comes from a solar water heater, a gas water heater or electric heating, etc. At this time, a part of the water diverted from the water supply 9 is mixed with the primary air through the humidification pipeline 11 and the humidification regulating valve 12 for heating and humidification, and the humidity of the indoor working air 8 is adjusted to be within the comfortable range for the human body, for example, the humidity is maintained in the range of 40% to 60%. At this time, the evaporative heat exchanger is actually a heating heater, and the indoor working air 8 is heating air.

[0045] When the application scenario of the evaporative heat exchanger 3 is a data center, the load required by the data center is a cooling load. At this time, the evaporative heat exchanger 3 is essentially an evaporative cooler.

[0046] Preferably, the wet air channel of the evaporative heat exchange tube 5 adopts the method of overflow water entering the inner wall of the wet air channel pipe, and the water supply inlet end of the evaporative heat exchange tube 5 is provided with an effective water supply guide cavity, such as symmetrical circular holes, U-shaped holes or other effective water supply inlet holes, so as to smoothly and effectively distribute water into the evaporative heat exchange tube.

[0047] Preferably, a water retaining plate 20 is provided on the upper portion of the evaporative heat exchanger 3 to prevent the exhaust air 3 from bringing out liquid water.

[0048] The evaporative heat exchanger 3 is provided with necessary sewage discharge, cleaning and maintenance ports.

[0049] A dehumidifier 25 is provided: primary air passes through the blower 2, the evaporative heat exchanger 3 and the dehumidifier 25 to become indoor working air 8.

[0050] The dehumidifier 25 uses membrane dehumidification technology to adjust the humidity of the cooling air, and adopts two parallel operation modes to maintain the indoor air humidity within a human comfort range (for example, the humidity is controlled at 40% to 60%).

[0051] An indoor air circulation pipeline 23 is provided: the indoor air is mixed with the primary air through the indoor air circulation pipeline 23, enters the blower 2 and the evaporative heat exchanger 3, becomes the indoor working air 8 and the exhaust air 13, and while maintaining the indoor air pressure stable, introduces outdoor fresh air as the indoor working air (for cooling or heating), avoiding the need to open doors and windows for ventilation in other operating modes of the air conditioner to maintain the freshness of the indoor air and a certain negative ion content.

[0052] The primary air (outdoor air) entering the blower 2 is filtered and dust-removed by adopting necessary measures and is equipped with a filter.

[0053] The present invention also proposes a control method for an evaporative heat exchanger, which is implemented by the evaporative heat exchanger recorded in any one of the above technical solutions. The control method comprises: A temperature sensing element is provided at the indoor working air outlet of the evaporative heat exchanger to detect whether the air supply temperature reaches the set value through the temperature sensing element; When the indoor working air temperature does not reach the set value after the evaporative heat exchanger has been running for a period of time, the cooling or heating capacity is increased by increasing the water supply; When the indoor working air temperature still does not reach the set value after increasing the water supply, adjust the blower damper and adjust the primary air intake to make the indoor working air temperature reach the set value.

[0054] The present invention application also proposes an air conditioner, comprising an evaporative heat exchanger recorded in any one of the above technical solutions.

[0055] The present invention can be provided with an indoor air electronic humidity detector to cooperate with the operation adjustment of the evaporative heat exchanger and the air conditioner.

[0056] Pipes, instruments, valves, bypass facilities with regulating functions, etc. not described in this application are matched with reference to or in accordance with the mature technologies in the well-known traditional evaporative heat exchanger and air conditioner processes.

[0057] Parts not mentioned in this application, such as safety accessories, interlocking protection devices and automatic control, are equipped with existing publicly known technologies, that is, existing mature, reliable and reasonable technical measures are applied to this evaporative heat exchanger and air conditioner.

[0058] 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. An evaporative heat exchanger, characterized in that: The evaporative heat exchanger comprises a shell, a head, a tube sheet, and evaporative heat exchange tubes. Primary air enters the shell side of the evaporative heat exchanger through a blower (2), passes horizontally through the gaps between the evaporative heat exchange tubes, and contacts and exchanges heat with the evaporative heat exchange tubes before being output as indoor working air (8). The evaporative heat exchanger is provided with an air inlet and a water supply inlet. A portion of the air diverted from the indoor working air (8) enters the evaporative heat exchange tube of the evaporative heat exchanger tube pass through the secondary air pipeline and the air inlet, and exchanges heat and moisture with the water supplied to the evaporative heat exchange tube port at the upper part of the evaporative heat exchanger from bottom to top, and then exchanges heat with the primary air outside the evaporative heat exchange tube, and is drawn out from the upper part of the evaporative heat exchanger to become exhaust air (13) for exhaust; The feed water that exchanges heat and moisture with the return gas falls into the gas-water separation chamber (16) of the evaporative heat exchanger and undergoes gas-water separation, and the separated water is discharged through the drainage regulating valve (18).

2. The evaporative heat exchanger according to claim 1, characterized in that: When the load required by the application scenario of the evaporative heat exchanger is a cooling load, the evaporative heat exchanger adopts an evaporative cooler operation mode, and the water supply of the evaporative heat exchanger adopts tap water, groundwater or chilled water; Alternatively, in winter, the evaporative heat exchanger is fed with hot water, and a portion of the water diverted from the water supply is mixed with the primary air through a humidification pipeline (11) and a humidification regulating valve (12) to be heated and humidified, thereby adjusting the humidity of the indoor working air (8) to a range comfortable for the human body, and the indoor working air (8) is heating air.

3. The evaporative heat exchanger according to claim 1, characterized in that: The evaporation heat exchange tube is a hollow round tube or a special-shaped tube, and the special-shaped tube is a hollow non-circular tube; when the evaporation heat exchange tube is a hollow round tube, a spiral groove tube is used.

4. The evaporative heat exchanger according to claim 1, characterized in that: A dehumidifier (25) is provided: primary air passes through the blower (2), the evaporative heat exchanger and the dehumidifier (25) to become indoor working air (8).

5. The evaporative heat exchanger according to claim 1, characterized in that: An indoor air circulation pipeline (23) is provided: the indoor air is mixed with the primary air through the indoor air circulation pipeline (23), and is discharged through the blower (2) and the evaporative heat exchanger to become indoor working air (8) and exhaust air (13).

6. The evaporative heat exchanger according to claim 1, characterized in that: The material of the evaporation heat exchange tube is hydrophilic aluminum foil, aluminum-magnesium alloy or stainless steel.

7. The evaporative heat exchanger according to claim 1, characterized in that: The wet air passage of the evaporative heat exchange tube adopts a method in which overflow water enters the inner wall of the wet air passage.

8. The evaporative heat exchanger according to claim 1, characterized in that: A water supply guide cavity is provided at the water supply inlet end of the evaporation heat exchange tube.

9. A method for controlling an evaporative heat exchanger, characterized in that: The evaporative heat exchanger described in one of claims 1 to 8 is implemented as follows: The control method includes: A temperature sensing element is provided at the indoor working air outlet of the evaporative heat exchanger to detect whether the air supply temperature reaches the set value through the temperature sensing element; When the indoor working air temperature does not reach the set value after the evaporative heat exchanger has been running for a period of time, the cooling or heating capacity is increased by increasing the water supply; When the indoor working air temperature still does not reach the set value after increasing the water supply, adjust the blower damper and adjust the primary air intake to make the indoor working air temperature reach the set value.

10. An air conditioner, characterized in that: The evaporative heat exchanger comprises the evaporative heat exchanger as claimed in any one of claims 1 to 8.

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