An indirect evaporative cooling spray system

Abstract

The utility model relates to the technical field of evaporative cooling, and specifically to an indirect evaporative cooling spray system, comprising an air-to-air heat exchanger, a first heat exchanger, a second heat exchanger, a spray system and a spray system; the air-to-air heat exchanger comprises an indoor air supply end, an outdoor exhaust end, an indoor return air end and an outdoor air inlet end; the spray system is arranged between the outdoor exhaust end and the first heat exchanger; the second heat exchanger is arranged at the indoor air supply end; the spray system is arranged at the outdoor air inlet end. In the wet mode working condition of the utility model, the upper spraying mode of the spray system cooperates with the precooling of the spray system, thereby significantly improving the energy efficiency of the wet mode; at the same time, it can reduce the mechanical refrigeration ratio, reduce the compressor start-up time, and save operating costs.

Description

Technical Field

[0001] The utility model relates to the technical field of evaporative cooling, in particular to an indirect evaporative cooling spray system. Background Art

[0002] With the rapid development of big data, cloud computing, artificial intelligence (AI), and 5G digital economy technology applications, the demand for new infrastructure such as data centers is becoming increasingly strong. The high energy consumption problem caused by this is becoming increasingly prominent, and the trend of data centers towards high density has placed higher and higher requirements on the cooling density and energy saving of single machines. Indirect evaporative cooling technology has many advantages such as green energy saving, fast delivery, and phased deployment, and is being used more and more widely in the field of data centers.

[0003] Indirect evaporative cooling is when the secondary side (outdoor side) air contacts the circulating water in the wet channel inside the heat exchange core before entering the heat exchange core, and then enters the heat exchange core to exchange heat with the primary side (indoor side) air after an isenthalpic cooling process. The primary side air is only cooled but not humidified when it flows through the dry channel of the heat exchange core, thereby achieving isohumid cooling of the primary side indoor air. In the data center scenario, the secondary side air of indirect evaporative cooling is generally outdoor fresh air, and the primary side air is generally the return air from the computer room. The return air from the indoor computer room is cooled by the temperature difference on both sides, and the insufficient part is met by setting up an auxiliary mechanical refrigeration system to meet the supply air temperature requirements.

[0004] In the existing technical solutions, there are two water distribution forms according to the secondary air flow direction: air-water co-direction and air-water reverse direction. There are three ways of air-water reverse non-central spraying:

[0005] Solution 1: Only the downward spraying method is used. In this solution, the airflow and water flow directions are the same. However, when the downward spraying method is used alone, the water film is affected by gravity and cannot fully wet the surface of the heat exchange core, resulting in some areas inside the heat exchange core still being in a dry working state, and the heat exchange capacity is reduced.

[0006] Solution 2: Only the upper spraying method is used. In this solution, the airflow is opposite to the water flow direction. When the upper spraying method is used alone, the spray droplets are affected by the wind and cannot fall completely on the heat exchange core, which also causes some areas inside the heat exchange core to be in a dry working state. In addition, this spraying method cannot pre-cool the air entering the heat exchange core, and the spraying effect is still poor.

[0007] Option three, adopts the arrangement of upper spray and lower spray, and adopts upper spray and lower spray at the same time. This option has the advantages of option one and option two, but the water mist of upper spray cannot fall well on the heat exchange core, and the heat exchange core is still not fully wetted, and the problem of low heat exchange efficiency in wet conditions still exists.

[0008] However, there are two disadvantages to using wet film to pre-cool fresh air: first, the presence of wet film increases the secondary wind resistance, which increases the power consumption of the outdoor fan to overcome the resistance of the wet film; second, the wet film is a consumable part, which increases the maintenance workload. The disadvantages of using a surface cooler to pre-cool the air are: first, the presence of the surface cooler increases the secondary wind resistance, which increases the power consumption of the outdoor fan to overcome the resistance of the surface cooler; second, the surface cooler itself is heavy, which increases the manufacturing cost; third, if circulating water is used inside the surface cooler to cool the fresh air, it will increase the water resistance and increase the requirements for the water pump head. In addition, water quality problems may affect the life of the surface cooler. Utility Model Content

[0009] The purpose of the utility model is to provide an indirect evaporative cooling spray system to effectively improve energy efficiency in view of the above-mentioned deficiencies in the prior art.

[0010] The purpose of the utility model is achieved through the following technical solutions: an indirect evaporative cooling spray system, comprising an air-to-air heat exchanger, a first fan, a second fan, a spray system and a mist system;

[0011] The air-to-air heat exchanger includes an indoor air supply end, an outdoor air exhaust end, an indoor return air end and an outdoor air inlet end; the spray system is arranged between the outdoor air exhaust end and the first fan; the second fan is arranged at the indoor air supply end; and the spray system is arranged at the outdoor air inlet end.

[0012] The utility model is further configured that the indirect evaporative cooling spray system also includes a first heat exchanger; the first heat exchanger is arranged between the first fan and the spray system.

[0013] The utility model is further configured that the indirect evaporative cooling spray system also includes a second heat exchanger; the second heat exchanger is arranged between the second fan and the indoor air supply end.

[0014] The utility model is further configured that the indirect evaporative cooling spray system also includes a water tank; the water tank is arranged at the bottom of the air-to-air heat exchanger.

[0015] The utility model is further configured that the spray system comprises a spray pipe.

[0016] The utility model is further configured as follows: the spray pipe is provided with a plurality of spray holes; the air-to-air heat exchanger is provided with a plurality of heat exchange channels at the outdoor exhaust end; and the spacing between two adjacent rows of spray holes is the same as the spacing between two adjacent heat exchange channels.

[0017] The utility model is further configured that the indirect evaporative cooling spray system also includes a circulation pump; the circulation pump is connected to the spray pipe and the water tank through a pipeline.

[0018] The utility model is further configured that a ball valve is provided between the circulation pump and the water tank; and a first filter is provided between the circulation pump and the spray pipe.

[0019] The utility model is further configured such that the spray system includes a high-pressure nozzle, a water inlet pipe and a high-pressure pump; the high-pressure nozzle is arranged at the outdoor air inlet end; the water inlet pipe is connected to the high-pressure nozzle through the high-pressure pump; and the water inlet pipe is provided with a water supply solenoid valve.

[0020] The utility model is further configured that: the water inlet pipe is provided with a second filter; a water supply pipe is provided between the water tank and the water inlet pipe; and the water supply pipe is provided with a water supply solenoid valve.

[0021] Beneficial effects of the utility model: Under the wet mode working condition, the upper spraying mode of the spray system cooperates with the pre-cooling of the spray system, thereby significantly improving the wet mode energy efficiency; at the same time, it can reduce the mechanical refrigeration ratio, reduce the compressor startup time, and save operating costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The utility model is further described using the accompanying drawings, but the embodiments in the accompanying drawings do not constitute any limitation to the utility model. A person skilled in the art can obtain other drawings based on the following drawings without creative work.

[0023] Figure 1 It is the structural principle diagram of the utility model;

[0024] Figure 2 It is a structural schematic diagram of the spray pipe of the utility model;

[0025] Figure 3 It is the enthalpy-psychrometric diagram of the utility model;

[0026] Among them: 1. air-to-air heat exchanger; 11. indoor air supply end; 12. outdoor exhaust end; 13. indoor return air end; 14. outdoor air inlet end; 2. first heat exchanger; 21. first fan; 3. second heat exchanger; 31. second fan; 4. water tank; 41. circulation pump; 42. ball valve; 43. first filter; 5. spray pipe; 51. spray hole; 6. high-pressure nozzle; 61. water inlet pipe; 62. high-pressure pump; 63. water supply solenoid valve; 64. second filter; 7. water replenishment solenoid valve. DETAILED DESCRIPTION

[0027] The utility model is further described in conjunction with the following embodiments.

[0028] Depend on Figures 1 to 3 It can be seen that the indirect evaporative cooling spray system described in this embodiment includes an air-to-air heat exchanger 1, a first fan 21, a second fan 31, a spray system and a mist system;

[0029] The air-to-air heat exchanger 1 includes an indoor air supply end 11, an outdoor air exhaust end 12, an indoor air return end 13 and an outdoor air inlet end 14; the spray system is arranged between the outdoor air exhaust end 12 and the first fan 21; the second fan 31 is arranged at the indoor air supply end 11; and the spray system is arranged at the outdoor air inlet end 14.

[0030] Specifically, compared with the reverse layout of the secondary side air and water in indirect evaporative cooling in a common data center, the advantage of this embodiment is that, in the wet mode, the upper spraying method of the spray system cooperates with the precooling of the spray system, thereby significantly improving the wet mode energy efficiency. At the same time, it can reduce the mechanical refrigeration ratio, reduce the compressor start-up time, and save operating costs.

[0031] The indirect evaporative cooling spray system described in this embodiment further includes a first heat exchanger 2; the first heat exchanger 2 is arranged between the first fan 21 and the spray system. Specifically, through the above arrangement, the first heat exchanger 2 can be used as a condenser, so as to facilitate exhausting air to the outside.

[0032] The indirect evaporative cooling spray system described in this embodiment further includes a second heat exchanger 3; the second heat exchanger 3 is arranged between the second fan 31 and the indoor air supply end 11. Specifically, through the above arrangement, the first heat exchanger 2 can be used as an evaporator, so as to facilitate air supply to the room.

[0033] The indirect evaporative cooling spray system described in this embodiment further includes a water tank 4; the water tank 4 is arranged at the bottom of the air-to-air heat exchanger 1. Specifically, the above arrangement facilitates the collection of water from the spray system and the spray system.

[0034] The indirect evaporative cooling spray system described in this embodiment includes a spray pipe 5. The above arrangement facilitates spraying of the air-to-air heat exchanger 1.

[0035] In the indirect evaporative cooling spray system described in this embodiment, the spray pipe 5 is provided with a plurality of spray holes 51; the air-to-air heat exchanger 1 is provided with a plurality of heat exchange channels at the outdoor exhaust end 12; the spacing between two adjacent rows of spray holes 51 is the same as the spacing between two adjacent heat exchange channels. Specifically, in this embodiment, by providing a plurality of spray holes 51, the traditional nozzle water distribution method is changed to the small hole water distribution of the spray pipe 5. Compared with the nozzle water distribution, the water flow of this embodiment is more likely to fall into the air-to-air heat exchanger 1 under the influence of gravity, so that it forms a uniform water film, increases the contact area between water and secondary air, and strengthens the heat exchange inside the air-to-air heat exchanger 1, thereby achieving the purpose of increasing energy efficiency. In addition, the spacing between two adjacent rows of spray holes 51 is the same as the spacing between two adjacent heat exchange channels, which can ensure that each wet channel on the secondary side can be fully wetted.

[0036] The indirect evaporative cooling spray system described in this embodiment further includes a circulation pump 41, which is connected to the spray pipe 5 and the water tank 4 through a pipeline. Specifically, through the above arrangement, the spray system can perform circulation work.

[0037] In the indirect evaporative cooling spray system described in this embodiment, a ball valve 42 is provided between the circulation pump 41 and the water tank 4; a first filter 43 is provided between the circulation pump 41 and the spray pipe 5. The above arrangement plays a filtering role to prevent impurities from entering the spray pipe 5.

[0038] The indirect evaporative cooling spray system described in this embodiment comprises a high-pressure nozzle 6, a water inlet pipe 61 and a high-pressure pump 62; the high-pressure nozzle 6 is arranged at the top of the water tank 4; the high-pressure nozzle 6 is arranged at the outdoor air inlet end 14; the water inlet pipe 61 is connected to the high-pressure nozzle 6 through the high-pressure pump 62; the water inlet pipe 61 is provided with a water supply solenoid valve 63; the water inlet pipe 61 is provided with a second filter 64. Specifically, the spray system of this embodiment uses tap water for direct supply, and uses the high-pressure pump 62 to pressurize the water purified by the second filter 64 (the maximum pressure can be above 7MPa), and the pressurized water is transported to the ultra-fine high-pressure nozzle 6 for atomization, and rotates at high speed, and is sprayed into the entire space with ultra-fine mist particles of 5 to 15μm, and the ultra-fine mist particles absorb heat in the air, vaporize, evaporate, increase the relative humidity of the air, and reduce the temperature, so as to achieve isenthalpic cooling after high-pressure micro-mist humidification.

[0039] In the indirect evaporative cooling spray system described in this embodiment, a water supply pipe is provided between the water tank 4 and the water inlet pipe 61; the water supply pipe is provided with a water supply solenoid valve 7. The above arrangement facilitates water supply to the water tank 4.

[0040] In addition, the above system can achieve the following functions:

[0041] When the system detects a need for spraying, it first checks whether the water level in the water tank 4 meets the requirement for starting the circulation pump 41. When the water level meets the requirement, the circulation pump 41 can be directly started to spray and enter the wet mode;

[0042] Detect the temperature and humidity of the outdoor fresh air, calculate the amount of water required for isenthalpic cooling of the outdoor air to the wet-bulb temperature, control the speed of the high-pressure pump 62 according to the calculation result (and add a certain margin) to achieve water supply on demand, and the circulating water in the water tank 4 is supplied through the water supply solenoid valve 7, which can reduce the waste of water resources and ensure that the unit works at a higher energy efficiency.

[0043] Example calculation 1: When the outdoor fresh air dry-bulb temperature is 23 / 16℃ and the fresh air volume is 80000m^3 / h, the fresh air moisture content is 8.51g / kg dry air, and the air density is 1.2kg / m^3. The fresh air is humidified to saturation state (the saturated moisture content is 11.41g / kg dry air). The amount of water required for atomization is: (11.41-8.51) / 1000*80000*1.2=278.4kg / h, multiplied by the surplus coefficient of 1.1, the atomization amount is 306.2kg / h. This atomization amount is converted into a speed signal and output to the high-pressure pump 62 to meet the fresh air cooling demand.

[0044] Example calculation 2: When the outdoor fresh air dry-bulb temperature is 40 / 19.5℃ and the fresh air volume is 80000m^3 / h, the fresh air moisture content is 5.81g / kg dry air, and the air density is 1.2kg / m^3. The fresh air is humidified to saturation state (the saturated state moisture content is 14.3g / kg dry air). The amount of water required for atomization is: (14.3-5.81) / 1000*80000*1.2=815kg / h, multiplied by the surplus coefficient of 1.1, the atomization amount is 896.5kg / h. This atomization amount is converted into a speed signal and output to the high-pressure pump 62 to meet the fresh air cooling demand.

[0045] Air and water treatment processes such as Figure 3 As shown: After the outdoor air point 1 is humidified by the spray system, it is cooled to a temperature close to the wet bulb temperature at isenthalpic rate and reaches state point 2. It is fully in contact with water inside the air-to-air heat exchanger 1, and the water continues to absorb heat and vaporize. At the same time, the secondary side air-water mixture fully exchanges heat with the primary side air, and the air increases enthalpy and humidifies to reach state point 3. Theoretically, the relative humidity at state point 3 (secondary side outlet) can be close to 100%, but due to the wet bulb efficiency, contact time and temperature rise inside the heat exchange core, the relative humidity at state point 3 can reach more than 60%, and the water temperature of the circulating water is close to the wet bulb temperature of state point 3.

[0046] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model, rather than to limit the protection scope of the utility model. Although the utility model has been described in detail with reference to the preferred embodiments, ordinary technicians in this field should understand that the technical solution of the utility model can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the utility model.

Claims

1. An indirect evaporative cooling spray system, characterized in that: It comprises an air-to-air heat exchanger (1), a first fan (21), a second fan (31), a spray system and a mist system; The air-to-air heat exchanger (1) comprises an indoor air supply end (11), an outdoor air exhaust end (12), an indoor air return end (13) and an outdoor air inlet end (14); the spray system is arranged between the outdoor air exhaust end (12) and the first fan (21); the second fan (31) is arranged at the indoor air supply end (11); and the spray system is arranged at the outdoor air inlet end (14).

2. The indirect evaporative cooling spray system according to claim 1, characterized in that: The indirect evaporative cooling spray system further comprises a first heat exchanger (2); the first heat exchanger (2) is arranged between the first fan (21) and the spray system.

3. The indirect evaporative cooling spray system according to claim 1, characterized in that: The indirect evaporative cooling spray system further comprises a second heat exchanger (3); the second heat exchanger (3) is arranged between the second fan (31) and the indoor air supply end (11).

4. The indirect evaporative cooling spray system according to claim 1, characterized in that: The indirect evaporative cooling spray system further comprises a water tank (4); the water tank (4) is arranged at the bottom of the air-to-air heat exchanger (1).

5. The indirect evaporative cooling spray system according to claim 4, characterized in that: The spray system comprises a spray pipe (5).

6. The indirect evaporative cooling spray system according to claim 5, characterized in that: The spray pipe (5) is provided with a plurality of spray holes (51); the air-to-air heat exchanger (1) is provided with a plurality of heat exchange channels at the outdoor exhaust end (12); The spacing between two adjacent rows of spray holes (51) is the same as the spacing between two adjacent heat exchange channels.

7. The indirect evaporative cooling spray system according to claim 6, characterized in that: The indirect evaporative cooling spray system further comprises a circulation pump (41); the circulation pump (41) is connected to the spray pipe (5) and the water tank (4) via a pipeline.

8. The indirect evaporative cooling spray system according to claim 7, characterized in that: A ball valve (42) is provided between the circulation pump (41) and the water tank (4); and a first filter (43) is provided between the circulation pump (41) and the spray pipe (5).

9. The indirect evaporative cooling spray system according to claim 4, characterized in that: The spray system comprises a high-pressure nozzle (6), a water inlet pipe (61) and a high-pressure pump (62); the high-pressure nozzle (6) is arranged at an outdoor air inlet end (14); the water inlet pipe (61) is connected to the high-pressure nozzle (6) via the high-pressure pump (62); and the water inlet pipe (61) is provided with a water supply solenoid valve (63).

10. The indirect evaporative cooling spray system according to claim 9, characterized in that: The water inlet pipe (61) is provided with a second filter (64); a water supply pipe is provided between the water tank (4) and the water inlet pipe (61); and the water supply pipe is provided with a water supply solenoid valve (7).

Images