Evaporative cooling chiller and method for operating the same

Abstract

The present invention discloses an evaporative cooling chiller, comprising a mechanical refrigeration system, an evaporative cooling system, a cooling channel inlet and a cooling channel outlet, wherein the refrigeration module of the mechanical refrigeration system has a first heat exchange channel, the heat exchange module of the evaporative cooling system has a second heat exchange channel, and further comprises a control valve group; the control valve group can optionally enable: the second heat exchange channel and the first heat exchange channel to be connected in series, or both, to be connected between the cooling channel inlet and the cooling channel outlet. For example, when the outdoor temperature is too low, resulting in the risk of freezing of the chilled water in the evaporative cooling system, the control valve group can be operated at this time so that only the mechanical refrigeration system is used to cool the cooling object. Therefore, the evaporative cooling chiller can effectively solve the problem of poor use effect of the evaporative cooling chiller. The present invention also discloses an operation method of the evaporative cooling chiller.

Description

Technical Field

[0001] The present invention relates to the technical field of temperature regulation, and more specifically, to an evaporative cooling chiller and also to an operating method of the evaporative cooling chiller. Background Art

[0002] With the rapid development of science and technology and the vigorous development of new domestic infrastructure, the speed and scale of data center construction are increasing day by day. Behind the rapid growth of data center scale is the huge energy consumption, of which the energy consumption of the refrigeration system accounts for about 40% of the total energy consumption of the data center. As the global "carbon neutrality" goal approaches, the demand for energy conservation and emission reduction in the data center industry has surged; the energy consumption standards for newly built data centers are getting higher and higher; and higher requirements are put forward for new, reliable, energy-saving, and quickly deployed data center cooling products.

[0003] At present, indirect evaporative cooling technology and related products of evaporative cooling cold water technology have been applied in data centers, achieving certain energy-saving effects and attracting certain attention and promotion in the industry. After long-term research by the inventors, it was found that there is still a lack of dedicated cooling systems for cooling data centers designed for low-temperature environments, such as environments with lower temperatures all year round, or environments with lower temperatures in winter due to seasonal changes. If the cold air outside the data center is directly introduced to cool the data center, the high humidity of the outdoor air may damage the equipment in the data center, and this method has the uncontrollability of the environment.

[0004] In summary, how to effectively solve the problem of poor performance of evaporative cooling chillers is an urgent problem that technicians in this field need to solve. Summary of the invention

[0005] In view of this, the first object of the present invention is to provide an evaporative cooling chiller, which can effectively solve the problem of poor performance of the evaporative cooling chiller. The second object of the present invention is to provide an operating method of the evaporative cooling chiller.

[0006] In order to achieve the above first object, the present invention provides the following technical solutions:

[0007] An evaporative cooling chiller comprises a mechanical refrigeration system, an evaporative cooling system, a cooling channel inlet and a cooling channel outlet, wherein the refrigeration module of the mechanical refrigeration system has a first heat exchange channel, the heat exchange module of the evaporative cooling system has a second heat exchange channel, and further comprises a control valve group; the control valve group can selectively enable: the second heat exchange channel and the first heat exchange channel, either one or both of which are sequentially connected in series, to be connected between the cooling channel inlet and the cooling channel outlet.

[0008] In the evaporative cooling water unit, when in use, according to the outdoor temperature, for example, when the outdoor temperature is too low, resulting in the risk of freezing of the chilled water in the evaporative cooling system, the control valve group can be operated at this time so that only the first heat exchange channel is connected in series between the cooling channel inlet and the cooling channel outlet, and then the mechanical refrigeration system is turned on to cool the cooling object. For example, when the outdoor temperature is slightly higher, so that the evaporative cooling system does not freeze, by operating the control valve group, only the second heat exchange channel is connected in series between the cooling channel inlet and the cooling channel outlet, and then the evaporative cooling system is turned on, and the mechanical refrigeration system is turned off, so that the evaporative cooling system cools the cooling object. When the outdoor temperature is higher, when the evaporative cooling system cannot meet the requirements, by operating the control valve group, the first heat exchange channel and the second heat exchange channel are connected in series between the cooling channel inlet and the cooling channel outlet, and then the evaporative cooling system and the mechanical refrigeration system are turned on at the same time to cool the cooling object. In summary, the evaporative cooling water chiller can effectively solve the problem of poor use effect of the evaporative cooling water chiller.

[0009] Preferably, the mechanical refrigeration system includes a compressor, a condenser, and a throttling element connected in sequence, the outlet of the throttling element is connected to the refrigerant channel of the refrigeration module, the outlet of the refrigerant channel is connected to the inlet of the compressor, and the refrigerant channel is in heat exchange contact with the first heat exchange channel; a first one-way valve and a compressor are arranged in parallel between the refrigeration module and the condenser; a second one-way valve and a refrigerant pump are arranged in parallel between the throttling element and the condenser.

[0010] Preferably, it also includes a controller for controlling the control valve group; when the outdoor dry-bulb temperature is less than a first preset temperature, the controller controls the control valve group to connect the first heat exchange channel between the cooling channel inlet and the cooling channel outlet, controls the pump body of the evaporative cooling system to stop working, and controls the refrigerant pump to start and the compressor to stop working; when the outdoor wet-bulb temperature is between the first preset temperature and the second preset temperature, the controller controls the control valve group to connect the second heat exchange channel between the cooling channel inlet and the cooling channel outlet, controls the refrigerant pump and the compressor to stop working, and controls the evaporative cooling system to start working; when the outdoor wet-bulb temperature is greater than the second preset temperature, the controller controls the control valve group to connect the cooling channel inlet, the second heat exchange channel, the first heat exchange channel and the cooling channel outlet in sequence, controls the evaporative cooling system to open, and controls the compressor to open.

[0011] Preferably, the inlet of the cooling channel is connected to the inlet of the second heat exchange channel through a first switch valve, and is connected to the middle port through a second switch valve; the outlet of the second heat exchange channel is connected to the middle port; the middle port is connected to the inlet of the first heat exchange channel through a third switch valve, and is connected to the outlet of the cooling channel through the fourth switch valve; the outlet of the first heat exchange channel is connected to the outlet of the cooling channel.

[0012] Preferably, the first switch valve, the second switch valve, the third switch valve and the fourth switch valve are all electric valves.

[0013] Preferably, the evaporative cooling system comprises a precooling device for precooling ambient air and a main cooling device for cooling water using the air cooled by the precooling device.

[0014] Preferably, the precooling equipment includes a precooling fan, a precooling spray pipe, a precooling evaporative heat exchange core, a precooling water receiving tray and a precooling water pump, the precooling spray pipe is used to spray water onto the precooling evaporative heat exchange core, the precooling water receiving tray is used to collect the water sprayed by the precooling spray pipe, the precooling fan is used to drive air to flow through the evaporative heat exchange core, and the precooling water pump is used to drive the water in the precooling water receiving tray to be transported to the precooling spray pipe.

[0015] Preferably, the main cooling equipment includes a main fan, a main spray pipe, a direct evaporation heat exchange filler, a main water receiving tray and a main cooling pump; the evaporative cooling system also includes a main cooling pump, which is used to pump cooling water in the main water receiving tray to the cooling water channel of the heat exchange module, and the outlet of the cooling water channel is connected to the main spray pipe, and the cooling water channel is in heat exchange contact with the second heat exchange channel; the main spray pipe is used to spray cooling water onto the direct evaporation heat exchange filler, the main water receiving tray is used to collect the cooling water flowing through the direct evaporation heat exchange filler, and the main fan is used to drive the cooling airflow of the pre-cooling equipment to flow through the direct evaporation heat exchange filler.

[0016] Preferably, the precooling device is a cooling coil.

[0017] Preferably, the main cooling device has at least two air inlets, and each air inlet is provided with the pre-cooling device.

[0018] Preferably, the heat exchange module is a plate heat exchanger, and the refrigeration module is one of a flooded evaporator, a falling film evaporator, a shell and tube evaporator, and a plate heat exchanger.

[0019] In order to achieve the above second purpose, the present invention also provides an evaporative cooling chiller operation method, which includes the following steps: when judging whether the outdoor dry-bulb temperature is less than a first preset value, starting the natural cooling cycle of the mechanical refrigeration system and shutting down the evaporative cooling system; when judging whether the outdoor wet-bulb temperature is between the first preset value and the second preset value, starting the evaporative cooling system and shutting down the mechanical refrigeration system; when judging whether the outdoor wet-bulb temperature is greater than the second preset value, starting the evaporative cooling system and starting the compression cooling cycle of the mechanical refrigeration system. The evaporative cooling chiller operation method is mainly applied to any of the above evaporative cooling chillers. Since the above evaporative cooling chillers have the above technical effects, the evaporative cooling chiller operation method should also have corresponding technical effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 A schematic diagram of the operation of an evaporative cooling chiller when the mechanical refrigeration system provided by an embodiment of the present invention enters a working state;

[0022] Figure 2 A schematic diagram of the operation of an evaporative cooling chiller when the evaporative cooling system provided by an embodiment of the present invention enters a working state;

[0023] Figure 3 A schematic diagram of the operation of an evaporative cooling chiller when the evaporative cooling system and the mechanical refrigeration system provided by an embodiment of the present invention enter a working state at the same time;

[0024] Figure 4 A flow chart of an evaporative cooling chiller operation method provided in an embodiment of the present invention.

[0025] The following are marked in the accompanying drawings:

[0026] 1. Main fan; 2. Precooling fan; 3. Precooling spray pipe; 4. Precooling evaporative heat exchange core; 5. Air inlet grille; 6. Precooling water pump; 7. Condenser; 8. Water collection tray; 9. Main spray pipe; 10. Direct evaporative heat exchange filler; 11. First one-way valve; 12. Refrigerant pump; 13. Precooling water collection tray; 14. Throttling element; 15. Refrigeration module; 16. Compressor; 17. Main cooling pump; 18. Heat exchange module; 19. Cooling pump; 20. First switch valve; 21. Second switch valve; 22. Third switch valve; 23. Fourth switch valve; 24. Liquid level switch; 25. Fourth one-way valve; 26. Third one-way valve; 27. Second one-way valve; 28. Middle port; 29. ​​Main water collection tray; 30. Cooling channel inlet; 31. Cooling channel outlet. DETAILED DESCRIPTION

[0027] The embodiment of the invention discloses an evaporative cooling water chiller to effectively solve the problem of poor use effect of the evaporative cooling water chiller.

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] See also Figure 1-4 , Figure 1 A schematic diagram of the operation of an evaporative cooling chiller provided by an embodiment of the present invention; Figure 2 A schematic diagram of the operation of an evaporative cooling chiller when the evaporative cooling system provided by an embodiment of the present invention enters a working state; Figure 3 A schematic diagram of the operation of an evaporative cooling chiller when the evaporative cooling system and the mechanical refrigeration system provided by an embodiment of the present invention enter a working state at the same time; Figure 4 A flow chart of an evaporative cooling chiller operation method provided in an embodiment of the present invention.

[0030] In a specific embodiment, this embodiment provides an evaporative cooling chiller, which mainly guides the cooling fluid to the target cooling object through the cooling channel, and the cooling fluid absorbs heat from the target cooling object, and then guides it back to the evaporative cooling chiller to cool it down and then guides it to the target cooling object again. Of course, the evaporative cooling chiller is also suitable for heating the target object through the cooling channel. The evaporative cooling chiller includes a mechanical refrigeration system, an evaporative cooling system, a cooling channel inlet 30, and a cooling channel outlet 31.

[0031] The mechanical refrigeration system, such as the common air conditioning system, mainly includes a compressor 16, a condenser 7, a throttling element 14 and an evaporator, wherein the evaporator is a refrigeration module 15 of the mechanical refrigeration system, and has a refrigerant channel and a first heat exchange channel in heat exchange contact with each other, wherein the refrigerant channel refers to a channel connected in series between the throttling element 14 and the compressor 16. When the mechanical refrigeration system is running, the fluid that can release low temperature through the throttling element 14 enters the refrigerant channel to absorb heat from the first heat exchange channel, and then flows to the compressor 16. Specifically, the structure of the mechanical refrigeration system is not specifically limited, and is based on the refrigeration module 15 that can refrigerate, so that the refrigeration module 15 can absorb heat from the fluid flowing through its first heat exchange channel.

[0032] The evaporative cooling system mainly uses cooling water to cool the air body to obtain low-temperature fluid. Specifically, the evaporative cooling system generally includes a fan, a spray pipe, an evaporative heat exchange core and a water receiving tray arranged in sequence from top to bottom, and also includes a water pump and a heat exchange module 18. The heat exchange module 18 has a cooling water channel and a second heat exchange channel that are in thermal contact with each other, wherein the water pump is used to pump the cooling water in the water receiving tray to the cooling water channel, and then absorb heat from the second heat exchange channel. After the cooling water in the cooling water channel absorbs heat, it flows into the spray pipe, and the spray pipe sprays cooling water into the evaporative heat exchange core. At this time, the fan is used to accelerate the flow of external air or cooled gas through the evaporative heat exchange core, prompting the cooling water to evaporate, and part of the cooling water evaporates to take away heat, so that the remaining cooling water is cooled, and then flows downward to the water receiving tray. The specific evaporative cooling system structure and its structural connection relationship are not specifically limited here, and the evaporative cooling can be performed by cooling water in the external environment to obtain a low-temperature fluid, and the low-temperature fluid flows into the cooling water channel of the heat exchange module 18, so that the heat exchange module 18 can absorb heat from the fluid flowing through its second heat exchange channel. The heat exchange module 18 is preferably a plate heat exchanger, and the refrigeration module 15 is one of a flooded evaporator, a falling film evaporator, a shell and tube evaporator, and a plate heat exchanger.

[0033] Here, it is preferred to further include a control valve group, one end of which is connected to the cooling channel inlet 30 and the cooling channel outlet 31, and the other end is connected to both ends of the first heat exchange channel and both ends of the second heat exchange channel. By adjusting the valve position of the control valve group, such as switching, switching, etc., it can be optionally realized that: the second heat exchange channel and the first heat exchange channel are connected in series, or both are connected in series, and then connected at the cooling channel inlet 30 and the cooling channel outlet 31. So that: when only the evaporative cooling system is needed for refrigeration, the control valve group can be operated to make the second heat exchange channel connected between the cooling channel inlet 30 and the cooling channel outlet 31; when only the mechanical refrigeration system is needed for refrigeration, the control valve group can be operated to make the first heat exchange channel connected between the cooling channel inlet 30 and the cooling channel outlet 31; when both the mechanical refrigeration system and the evaporative cooling system are needed for refrigeration, the control valve group can be operated to make the second heat exchange channel and the first heat exchange channel connected in series and connected between the cooling channel inlet 30 and the cooling channel outlet 31. Specifically, the connection mode after series connection here can be: the cooling channel inlet 30, the first heat exchange channel, the second heat exchange channel and the cooling channel outlet 31 are connected in sequence, or: the cooling channel inlet 30, the second heat exchange channel, the first heat exchange channel and the cooling channel outlet 31 are connected in sequence. Generally, the latter connection mode is preferably adopted. A cooling pump 19 is generally provided at the cooling channel inlet 30 to accelerate the flow of the internal cooling fluid.

[0034] In the evaporative cooling chiller, when in use, according to the outdoor temperature, for example, when the outdoor temperature is too low, resulting in the risk of freezing of the chilled water in the evaporative cooling system, the control valve group can be operated at this time so that only the first heat exchange channel is connected in series between the cooling channel inlet 30 and the cooling channel outlet 31, and then the mechanical refrigeration system is turned on to cool the cooling object. For example, when the outdoor temperature is slightly higher, so that the evaporative cooling system is not likely to freeze, the control valve group is operated so that only the second heat exchange channel is connected in series between the cooling channel inlet 30 and the cooling channel outlet 31, and then the evaporative cooling system is turned on and the mechanical refrigeration system is turned off so that the evaporative cooling system cools the cooling object. When the outdoor temperature is higher, when the evaporative cooling system cannot meet the requirements, the control valve group is operated so that the first heat exchange channel and the second heat exchange channel are connected in series between the cooling channel inlet 30 and the cooling channel outlet 31, and then the evaporative cooling system and the mechanical refrigeration system are turned on at the same time to cool the cooling object. In summary, the evaporative cooling chiller can effectively solve the problem of poor use effect of the evaporative cooling chiller.

[0035] As described above, the control valve group can be a reversing valve, such as the reversing valve body can have a working inlet, a working outlet, a first outlet, a first inlet, a second outlet, and a second inlet, the working inlet is connected to the cooling channel inlet 30, the working outlet is connected to the cooling channel outlet 31, the first outlet is connected to the first heat exchange channel outlet, the second outlet is connected to the second heat exchange channel outlet, the first inlet is connected to the first heat exchange channel inlet, and the second inlet is connected to the second heat exchange channel inlet. The valve core of the reversing valve has at least three working positions, which are: the first working position, the reversing valve core has a connecting channel to connect the working inlet with the first inlet, and has a connecting channel to connect the working outlet with the first outlet, while the second inlet and the second outlet are blocked, and the mechanical refrigeration system enters the working state; the second working position, the reversing valve core has a connecting channel to connect the working inlet with the second inlet, and has a connecting channel to connect the working outlet with the second outlet, while the first inlet and the first outlet are blocked, and the evaporative cooling system enters the working state; the third working position, the reversing valve core has a connecting channel to connect the working inlet with the second inlet, and has a connecting channel to connect the working outlet with the first outlet, and has a connecting channel to connect the second outlet with the first inlet, and both the evaporative cooling system and the mechanical refrigeration system enter the working state.

[0036] Of course, the control valve group can also include multiple separate valves for separate control, such as a first switch valve 20, a second switch valve 21, a third switch valve 22 and a fourth switch valve 23. The specific connection method is as follows: the cooling channel inlet 30 is connected to the second heat exchange channel inlet through the first switch valve 20, and is connected to the middle port 28 through the second switch valve 21; the outlet of the second heat exchange channel is connected to the middle port 28; the middle port 28 is connected to the inlet of the first heat exchange channel through the third switch valve 22, and is connected to the cooling channel outlet 31 through the fourth switch valve 23; the outlet of the first heat exchange channel is connected to the cooling channel outlet 31. The middle port 28 is added for the convenience of describing the connection relationship, and a connecting port is not necessarily required. So that: Figure 1 When the mechanical refrigeration system is only required to enter the working state, the first switch valve 20 and the fourth switch valve 23 are controlled to be closed, and the second switch valve 21 and the third switch valve 22 are opened; Figure 2 When only the evaporative cooling system is required to enter the working state, the second switch valve 21 and the third switch valve 22 are controlled to be closed, and the first switch valve 20 and the fourth switch valve 23 are controlled to be opened; Figure 3 When the evaporative cooling system and the mechanical refrigeration system are required to enter the working state at the same time, the second switch valve 21 and the fourth switch valve 23 are controlled to be closed, and the first switch valve 20 and the third switch valve 22 are controlled to be opened.

[0037] For the convenience of control, a controller is preferably included here, so that the first switch valve 20, the second switch valve 21, the third switch valve 22 and the fourth switch valve 23 are all electric valves, and are all control-connected to the controller, wherein the control connection means that the control signal of the controller can be transmitted to the first switch valve 20, the second switch valve 21, the third switch valve 22 and the fourth switch valve 23 to control the opening and closing of the above four switch valves respectively.

[0038] Specifically, two temperature values ​​are set, namely, a first preset temperature and a second preset temperature which increase in sequence and are both greater than 0 degrees Celsius. When the outdoor dry-bulb temperature is less than the first preset temperature, the controller controls the first switch valve 20 and the fourth switch valve 23 to be closed, and the second switch valve 21 and the third switch valve 22 to be opened, and the mechanical refrigeration system enters the working state; when the outdoor wet-bulb temperature is between the first preset temperature and the second preset temperature, the controller controls the second switch valve 21 and the third switch valve 22 to be closed, and the first switch valve 20 and the fourth switch valve 23 to be opened, and the mechanical refrigeration system enters the working state; when the outdoor wet-bulb temperature is greater than the second preset temperature, the controller controls the second switch valve 21 and the fourth switch valve 23 to be closed, and the first switch valve 20 and the third switch valve 22 to be opened, and the evaporative cooling system and the mechanical refrigeration system enter the working state at the same time.

[0039] Furthermore, in order to better perform evaporative cooling, it is preferred that the evaporative cooling system includes a precooling device for precooling the ambient air and a main cooling device for cooling water using the air cooled by the precooling device. Specifically, the precooling device can be provided on both sides or one side of the main cooling device. Specifically, the main cooling device can have at least two air inlets, each of which is provided with the precooling device. The precooling device is a cooling coil, and the cooling coil can be used to replace the indirect evaporative cooling core to achieve the precooling effect of outdoor high wet-bulb air; the cooling coil can be selected from but not limited to copper tube coils, copper tube fin coils, plate tubes, air-to-air heat exchangers, etc.

[0040] Specifically, the precooling equipment may include a precooling fan 2, a precooling spray pipe 3, a precooling evaporative heat exchange core 4, a precooling water receiving tray 13 and a precooling water pump 6. The precooling fan 2, the precooling spray pipe 3, the precooling evaporative heat exchange core 4 and the precooling water receiving tray 13 may be arranged in sequence from top to bottom, or may be arranged in other ways.

[0041] The precooling spray pipe 3 is used to spray water onto the precooling evaporative heat exchange core 4, the precooling water receiving tray 13 is used to collect the water sprayed by the precooling spray pipe 3, the precooling fan 2 is used to drive air to flow through the evaporative heat exchange core 4, and the precooling water pump 6 is used to drive the water in the precooling water receiving tray 13 to be transported to the precooling spray pipe 3.

[0042] The precooling evaporative heat exchange core 4 may also use direct evaporative heat exchange filler. An air inlet grille 5 is also provided between the precooling evaporative heat exchange core 4 and the precooling water receiving tray 13 to allow the air to enter the cavity between the precooling evaporative heat exchange core 4 and the precooling water receiving tray 13.

[0043] Furthermore, the main cooling device may include a main fan 1, a main spray pipe 9, a direct evaporation heat exchange filler 10, a main water receiving tray 29 and a main cooling pump 17. The main fan 1, the main spray pipe 9, the direct evaporation heat exchange filler 10 and the main water receiving tray 29 may be arranged in sequence from top to bottom, or in other arrangements. Generally, a water collecting tray 8 may be arranged between the main fan 1 and the main spray pipe 9, and generally, the condenser 7 may be arranged between the water collecting tray 8 and the main fan 1. The main spray pipe 9 is used to spray cooling water to the direct evaporation heat exchange filler 10, the main water receiving tray 29 is used to collect the cooling water flowing through the direct evaporation heat exchange filler 10, and the main fan 1 is used to drive the cooling airflow of the pre-cooling device to flow through the direct evaporation heat exchange filler 10. The direct evaporation heat exchange filler 10 may also adopt an evaporation heat exchange core. The evaporative cooling system further includes a main cooling pump 17, which is used to pump the cooling water in the main water receiving pan 29 to the cooling water channel of the heat exchange module 18, that is, the inlet of the main cooling pump 17 is connected to the outlet of the main water receiving pan 29, and the outlet is connected to the cooling water channel through a water pipe. Generally, the main cooling pump 17 is set lower than the main water receiving pan 29. The outlet of the cooling water channel is connected to the main spray pipe 9, and the cooling water channel is in heat exchange contact with the second heat exchange channel. The air inlet of the pre-cooling evaporative heat exchange core 4 introduces outside air, and the air outlet guides the air to the direct evaporative heat exchange filler 10.

[0044] When in use, the outdoor air (primary air) is cooled by the pre-cooling evaporative heat exchange core 4, so that the wet bulb temperature of the primary air is reduced. The cooling water return water in the main water receiving tray 29 is pumped by the main cooling pump 17 to the cooling water channel of the heat exchange module 18, and after heat exchange with the high-temperature refrigerated return water in the second heat exchange channel, it is evenly sprayed to the surface of the direct evaporative heat exchange filler 10 through the main spray pipe 9; at this time, the primary air cooled by the pre-cooling evaporative heat exchange core is directly evaporated and heat-exchanged with the cooling water return water on the surface of the direct evaporative heat exchange filler 19, so that the cooling water return water temperature is lower than the outdoor wet bulb temperature; compared with the traditional cooling tower, which is limited by the approximation, it can only produce water 2~3℃ higher than the wet bulb problem, while the evaporative cooling system can produce water lower than the outdoor air wet bulb temperature (close to the dew point temperature), which can significantly increase the use time of natural cooling.

[0045] Furthermore, a liquid level switch 24 may be provided in the main water receiving tray 29 to control the main cooling pump 17 to stop running when the liquid level in the main water receiving tray 29 is low.

[0046] The mechanical refrigeration system includes a compressor 16, a condenser 7, and a throttling element 14 which are connected in sequence along the fluid flow direction, and the outlet of the throttling element 14 is connected to the refrigerant channel of the refrigeration module 15, the outlet of the refrigerant channel is connected to the inlet of the compressor 16, and the refrigerant channel is in heat exchange contact with the first heat exchange channel.

[0047] Furthermore, in order to allow the refrigerant to flow to the condenser 7 without passing through the compressor 16, it is preferred that a first one-way valve 11 and the compressor 16 are arranged in parallel between the refrigeration module 15 and the condenser 7. The first one-way valve 11 is arranged in parallel with the compressor 16, so that the fluid flowing out of the refrigerant channel of the refrigeration module 15 can flow to the condenser 7 after being compressed by the compressor 16, or can flow directly to the condenser 7 through the first one-way valve 11 without passing through the compressor 16.

[0048] In order to accelerate the flow of internal refrigerant, a second one-way valve 27 and a refrigerant pump 12 may be provided in parallel between the throttling element 14 and the condenser 7, so that the fluid flowing out of the condenser 7 can flow to the throttling element 14 after being pressurized by the refrigerant pump 12, or can flow to the throttling element directly through the second one-way valve 27 without passing through the refrigerant pump 12.

[0049] Specifically, when the controller is controlling, when the outdoor dry-bulb temperature is less than the first preset temperature: control the control valve group to connect the first heat exchange channel between the cooling channel inlet 30 and the cooling channel outlet 31, so that the mechanical refrigeration system enters the working state, control the evaporative cooling system to stop working, such as closing its pump body, and control the refrigerant pump 12 to start and the compressor 16 to stop, so that the mechanical refrigeration system has a natural cooling cycle; when the outdoor wet-bulb temperature is between the first preset temperature and the second preset temperature: control the control valve group to connect the second heat exchange channel to the cooling channel inlet 30 and the cooling channel outlet 31, so that the mechanical refrigeration system enters the working state, and control the evaporative cooling system to stop working, such as closing its pump body, and control the refrigerant pump 12 to start and the compressor 16 to stop, so that the mechanical refrigeration system has a natural cooling cycle; when the outdoor wet-bulb temperature is between the first preset temperature and the second preset temperature, the controller Between the channel inlet 30 and the cooling channel outlet 31, the refrigerant pump 12 and the compressor 16 are controlled to be closed, and the evaporative cooling system is controlled to start working, such as turning on the pump body and the fan, so that the evaporative cooling system enters the working state; when the outdoor wet-bulb temperature is greater than the second preset temperature: the controller controls the control valve group to connect the cooling channel inlet 30, the second heat exchange channel, the first heat exchange channel and the cooling channel outlet 31 in sequence, controls the evaporative cooling system to start, and the corresponding pump body and fan start working, and controls the compressor 16 to start, so that the mechanical refrigeration system compresses the cold cycle.

[0050] If the control valve group includes the above-mentioned first switch valve 20, second switch valve 21, third switch valve 22 and fourth switch valve 23, when the outdoor dry-bulb temperature is less than the first preset temperature, the controller controls the first switch valve 20 and the fourth switch valve 23 to be closed, controls the second switch valve 21 and the third switch valve 22 to be opened, controls the pump body of the evaporative cooling system to be closed, and controls the refrigerant pump 12 to be turned on and the compressor 16 to be turned off; when the outdoor wet-bulb temperature is between the first preset temperature and the second preset temperature, the controller controls the second switch valve 21 and the third switch valve 22 to be closed, controls the first switch valve 20 and the fourth switch valve 23 to be opened, controls the refrigerant pump 12 and the compressor 16 to be turned off, and controls the pump body and the fan of the evaporative cooling system to be turned on; when the outdoor wet-bulb temperature is greater than the second preset temperature, the controller controls the second switch valve 21 and the fourth switch valve 23 to be closed, controls the first switch valve 20 and the third switch valve 22 to be opened, controls the evaporative system to be turned on, and controls the compressor 16 to be turned on.

[0051] When the outdoor wet-bulb temperature is too high and the outlet water temperature of the evaporative cooling system does not meet the design requirements, the mechanical refrigeration system is turned on, at which time the second switch valve 21 and the fourth switch valve 23 are closed, and the first switch valve 20 and the third switch valve 22 are opened. When the outdoor dry-bulb temperature is too low, in order to avoid the risk of spraying and freezing pipes in winter, the mechanical refrigeration system is naturally refrigerated. At this time, the first switch valve 20 and the fourth switch valve 23 are closed, and the second switch valve 21 and the third switch valve 22 are opened; after the gaseous refrigerant in the refrigerant channel of the refrigeration module 15 absorbs heat, it passes through the first one-way valve 11 and directly enters the condenser 7 to release heat, and then the fluid flowing out of the condenser 7 is pressurized by the refrigerant pump 12, and then throttled and reduced in pressure by the throttling element 14, and then enters the refrigerant channel to absorb heat.

[0052] Further, the outlet of the compressor 16 may be provided with a third one-way valve 26 in parallel with the first one-way valve 11, so that the fluid flowing out of the outlet of the compressor 16 flows to the condenser 7 through the third one-way valve 26, thereby preventing the fluid flowing out of the first one-way valve 11 from flowing back from the compressor 16. Further, the outlet of the refrigerant pump 12 may be provided with a fourth one-way valve 25 in parallel with the second one-way valve 27, so that the fluid flowing out of the outlet of the refrigerant pump 12 needs to flow to the throttling element 14 through the fourth one-way valve 25, thereby preventing the fluid flowing out of the second one-way valve 27 from flowing back from the refrigerant pump 12. Further, in order to ensure the working efficiency of the throttling element 14 and to avoid the damage of one throttling element 14, resulting in shutdown, it is preferred that two throttling elements 14 are provided in parallel, that is, in parallel between the condenser 7 and the refrigeration module 15. The condenser 7 is preferably provided between the main fan 1 and the main spray pipe 9.

[0053] In a specific embodiment, the evaporative cooling system includes the above-mentioned pre-cooling device and main cooling device. Given the outdoor air wet-bulb temperature \(t_w\), outdoor dry-bulb temperature \(t_d\), set value \(t_0\) of the chilled water outlet temperature, set value \(t_1\) of the cooling water pump outlet temperature, where \(t_1 < t_0\), set value \(a\%\) of the evaporator liquid level (\(10 < a < 90\)), outdoor dry-bulb temperature \(m\), wet-bulb temperatures \(n\), \(p\) (\(0 < m < n < p\)), the controller can control in the following control modes.

[0054] When the outdoor dry-bulb temperature \(t_d < m\), the mechanical refrigeration system operates in the natural cooling mode at this time. The first switching valve 20 and the fourth switching valve 23 are closed, and the second switching valve 21 and the third switching valve 22 are opened; the cooling water directly enters the first heat exchange channel of the refrigeration module 15 for heat exchange. At this time, after the main fan 1 on the upper side of the condenser 7 runs at full speed for a specified time, it is judged that the liquid level in the refrigeration module 15 reaches the set value \(a\%\), then after the second switching valve 21 is opened, the first switching valve 20 is closed, and the main fan 1 is adjusted according to the set outlet temperature. The cooling channel inlet 30 is adjusted according to the main pipe pressure difference to match the terminal load, and the throttling element 14 is adjusted by the set liquid level PID. At this time, the pre-cooling fan 2, the pre-cooling water pump 6, the main cooling pump 17, and the compressor 16 do not operate, making full use of the outdoor natural cold source to achieve the purpose of energy-saving and cooling; at the same time, the unit realizes operation without primary cooling water, and the system has no risk of frozen pipes and icing. There is no need to arrange electric tracing for the water tray and primary water pipeline, simplifying the pipeline design and maintenance, and further saving energy consumption.

[0055] When the outdoor wet-bulb temperature \(m < t_w < n\), at this time, the natural cooling mode of the mechanical refrigeration system cannot meet the refrigeration demand, and the operation of the evaporative cooling system can meet the cooling demand, so it can be switched to the direct evaporative cooling mode. The first switching valve 20 is opened, while the second switching valve 21 is closed, and the main cooling pump 17 is started, and the main fan 1 runs at full speed. When it is detected that the cooling water temperature at the outlet of the main cooling pump 17 ≤ \(t_1\), after the fourth switching valve 23 is opened, the third switching valve 22 is closed, and the main fan 1 is adjusted according to the set outlet temperature, and the pre-cooling fan 2 remains closed. The unit provides the required refrigeration capacity through direct evaporation.

[0056] When the outdoor wet-bulb temperature \(n < t_w < p\), with the increase of the outdoor wet-bulb temperature, direct evaporation by only the main cooling device is not sufficient to reduce the primary water to the target temperature. At this time, the pre-cooling device is turned on to enable the indirect evaporation combined with direct evaporation mode. After the outdoor air undergoes wet cooling through the pre-cooling evaporation heat exchange core, the wet-bulb temperature decreases, and then it enters the direct evaporation heat exchange packing to exchange heat with the primary water return water, obtaining the primary water supply with a temperature lower than the outdoor wet-bulb temperature to make up for the required refrigeration capacity. On the basis of the direct evaporation mode, the pre-cooling fan runs at full speed; when it is detected that the cooling water temperature at the outlet of the main cooling pump ≤ \(t_1\), the pre-cooling fan adjusts according to the speed ratio matching the main fan.

[0057] When the outdoor wet-bulb temperature tw>p, as the outdoor wet-bulb temperature continues to rise, the direct evaporation compound indirect evaporation cooling mode cannot meet the cooling demand. When the unit outlet water temperature>t0, the mechanical supplementary cooling is turned on. On the basis of the above-mentioned composite mode, the third switch valve 22 is opened and the fourth switch valve 23 is closed, the compressor 16 is started, the compressor 16 frequency is adjusted according to the evaporation pressure, the main fan 1 is adjusted according to the condensing pressure, and the pre-cooling fan 2 is adjusted to match the main fan 1 speed ratio. As the outdoor wet-bulb temperature decreases, the mechanical supplementary cooling mode, the indirect evaporation and direct evaporation composite mode, the direct evaporation mode are gradually exited, until the fluorine pump natural cooling mode is entered, and the switching cycle of different modes of the system is completed, so as to achieve energy-saving operation of the unit throughout the year.

[0058] Based on the evaporative cooling chiller provided in the above embodiment, the present invention also provides an evaporative cooling chiller operation method, which includes the following steps: Step 100: When judging whether the outdoor dry-bulb temperature is less than the first preset value, start the natural cooling cycle of the mechanical refrigeration system and turn off the evaporative cooling system; Step 200: When judging whether the outdoor wet-bulb temperature is between the first preset value and the second preset value, start the evaporative cooling system and turn off the mechanical refrigeration system; Step 300: When judging whether the outdoor wet-bulb temperature is greater than the second preset value, start the evaporative cooling system and start the compression cooling cycle of the mechanical refrigeration system. The evaporative cooling chiller operation method is mainly applied to any of the above evaporative cooling chillers. Therefore, please refer to the above embodiment for the beneficial effects of the evaporative cooling chiller operation method. It should be noted that the above steps 100 to 300 can be performed in sequence or not.

[0059] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0060] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An evaporative cooling chiller, comprising a mechanical refrigeration system, an evaporative cooling system, a cooling channel inlet and a cooling channel outlet, wherein the refrigeration module of the mechanical refrigeration system has a first heat exchange channel, and the heat exchange module of the evaporative cooling system has a second heat exchange channel, characterized in that: It also includes a control valve group; the control valve group can make: the second heat exchange channel and the first heat exchange channel, one or both of which are connected in series in sequence, connected between the cooling channel inlet and the cooling channel outlet; and a controller for controlling the control valve group; When the outdoor dry-bulb temperature is less than a first preset temperature, the controller controls the control valve group to connect the first heat exchange channel between the cooling channel inlet and the cooling channel outlet, controls the evaporative cooling system to stop working, and controls the refrigerant pump to start and the compressor to stop, so that the mechanical refrigeration system performs a natural cooling cycle; When the outdoor wet-bulb temperature is between the first preset temperature and the second preset temperature, the controller controls the control valve group to connect the second heat exchange channel between the cooling channel inlet and the cooling channel outlet, controls the refrigerant pump and the compressor to be turned off, and controls the evaporative cooling system to start working; When the outdoor wet-bulb temperature is greater than a second preset temperature, the controller controls the control valve group to connect the cooling channel inlet, the second heat exchange channel, the first heat exchange channel and the cooling channel outlet in sequence, controls the evaporative cooling system to open, and controls the compressor to open, so that the mechanical refrigeration system compresses the cooling cycle.

2. The evaporative cooling chiller according to claim 1, characterized in that: The mechanical refrigeration system includes a compressor, a condenser, and a throttling element which are connected in sequence, the outlet of the throttling element is connected to the refrigerant channel of the refrigeration module, the outlet of the refrigerant channel is connected to the inlet of the compressor, and the refrigerant channel is in heat exchange contact with the first heat exchange channel; a first one-way valve and a compressor are arranged in parallel between the refrigeration module and the condenser, and a second one-way valve and a refrigerant pump are arranged in parallel between the throttling element and the condenser.

3. The evaporative cooling chiller according to claim 1, characterized in that: The control valve group includes a first switch valve, a second switch valve, a third switch valve and a fourth switch valve; the inlet of the cooling channel is connected to the inlet of the second heat exchange channel through the first switch valve, and is connected to the middle port through the second switch valve; the outlet of the second heat exchange channel is connected to the middle port; the middle port is connected to the inlet of the first heat exchange channel through the third switch valve, and is connected to the outlet of the cooling channel through the fourth switch valve; the outlet of the first heat exchange channel is connected to the outlet of the cooling channel.

4. The evaporative cooling chiller according to claim 3, characterized in that: The first switch valve, the second switch valve, the third switch valve, and the fourth switch valve are all electric valves.

5. The evaporative cooling chiller according to any one of claims 1 to 4, characterized in that: The evaporative cooling system comprises a precooling device for precooling ambient air and a main cooling device for cooling water using the air cooled by the precooling device.

6. The evaporative cooling chiller according to claim 5, characterized in that: The precooling equipment includes a precooling fan, a precooling spray pipe, a precooling evaporative heat exchange core, a precooling water receiving tray and a precooling water pump. The precooling spray pipe is used to spray water onto the precooling evaporative heat exchange core, the precooling water receiving tray is used to collect the water sprayed by the precooling spray pipe, the precooling fan is used to drive air to flow through the evaporative heat exchange core, and the precooling water pump is used to drive the water in the precooling water receiving tray to be transported to the precooling spray pipe.

7. The evaporative cooling chiller according to claim 5, characterized in that: The main cooling equipment includes a main fan, a main spray pipe, a direct evaporation heat exchange filler, a main water receiving tray and a main cooling pump. The main cooling pump is used to pump cooling water in the main water receiving tray to the cooling water channel of the heat exchange module. The outlet of the cooling water channel is connected to the main spray pipe, and the cooling water channel is in heat exchange contact with the second heat exchange channel. The main spray pipe is used to spray cooling water to the direct evaporation heat exchange filler, the main water receiving tray is used to collect the cooling water flowing through the direct evaporation heat exchange filler, and the main fan is used to drive the cooling airflow of the pre-cooling equipment to flow through the direct evaporation heat exchange filler.

8. The evaporative cooling chiller according to claim 7, characterized in that: The precooling device is a cooling coil.

9. The evaporative cooling chiller according to claim 8, characterized in that: The main cooling device has at least two air inlets, and each air inlet is provided with the pre-cooling device.

10. The evaporative cooling chiller according to any one of claims 1 to 4, characterized in that: The heat exchange module is a plate heat exchanger, and the refrigeration module is one of a flooded evaporator, a falling film evaporator, a shell and tube evaporator, and a plate heat exchanger.

11. A method for operating an evaporative cooling chiller, characterized in that: The operation of the evaporative cooling chiller according to any one of claims 1 to 10 comprises the following steps: When it is determined that the outdoor dry-bulb temperature is less than a first preset value, the natural cooling cycle of the mechanical refrigeration system is started, and the evaporative cooling system is turned off; when it is determined that the outdoor wet-bulb temperature is between the first preset value and the second preset value, the evaporative cooling system is started, and the mechanical refrigeration system is turned off; when it is determined that the outdoor wet-bulb temperature is greater than the second preset value, the evaporative cooling system is started, and the compression cooling cycle of the mechanical refrigeration system is started.

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