Control method and device for cascade refrigeration system of data center

Abstract

The invention provides a data center cascade refrigeration system control method and device, and the method comprises the steps: obtaining an outdoor wet bulb temperature to determine a first target temperature, obtaining an indoor return air temperature to determine a second target temperature, and calculating the temperature difference between the first target temperature and the second target temperature; the data center cascade refrigeration system is controlled to enter a first refrigeration mode, a second refrigeration mode or a third refrigeration mode according to preset conditions, and only the chilled water refrigeration system is started in the first refrigeration mode; in the second refrigeration mode, the chilled water refrigeration system and the evaporation cold and heat pipe refrigeration system are started at the same time; and in the third refrigeration mode, only the evaporation cold and heat pipe refrigeration system is started. In different modes, the system optimizes the refrigeration effect by adjusting the compressor frequency, the water pump frequency, the water supply valve opening, the fan frequency, the fluorine pump frequency, the expansion valve opening and other parameters, and the problems that in an existing refrigeration system in the prior art, the water side natural cooling time is short due to the fact that the temperature difference between the air side and the water side is inconsistent are solved. And more energy is consumed to meet the refrigeration requirement.

Description

Technical Field

[0001] The present invention relates to the field of data center refrigeration technology, and in particular to a control method and device for a data center cascade refrigeration system, a computer-readable storage medium, and a data center cascade refrigeration system. Background Art

[0002] As the infrastructure for the application of new generation information technology such as cloud computing and big data, data centers consume more than 1.5% of the total energy consumption. To ensure the safety and performance of data centers, the energy consumption of the cooling system accounts for more than 50% of the energy consumption of data center infrastructure. Therefore, tapping the energy-saving potential of the cooling system of data centers and improving energy efficiency have become the key to energy saving and consumption reduction in data centers.

[0003] In the prior art, the refrigeration system of the data center generally adopts a conventional chilled water system. In the conventional water-cooled chilled water system, the cooling water must reduce the temperature as much as possible to meet the temperature requirements of the plate exchange pre-cooling, and meet the minimum inlet water temperature of the chiller. To ensure the safe operation of the chiller, it is necessary to reduce the frequency of the cooling tower, appropriately increase the cooling water temperature, reduce the pre-cooling time, and increase the cooling time and proportion of the chiller. The energy consumption of the refrigeration system is increased. At the same time, the temperature difference of the chilled water of the precision air conditioner in the data center is generally 6°C, and the temperature difference of the air supply and return air of the air conditioner is generally 12°C. The return air of the air conditioner is cooled by a single coil, or a dual cold source coil air conditioner is used. The two coils are independent and standby, not a relay cooling method. The large temperature difference of the air conditioner return air is not effectively utilized for energy saving.

[0004] In summary, how to improve the cooling efficiency of data centers and reduce the cooling energy consumption of data centers has become the key to energy saving in data center cooling systems. When the temperature difference between the chilled water of precision air conditioners and the temperature difference between the air supply and return air of air conditioners is large, there is a lack of a method for achieving low-energy cooling in the prior art. Summary of the invention

[0005] The main purpose of the present application is to provide a control method, device, computer-readable storage medium and data center cascade refrigeration system for a data center, so as to at least solve the problem in the prior art that the temperature difference between the wind side and the water side of the existing refrigeration system is inconsistent, resulting in a short natural cooling time on the water side and more energy consumption to meet the refrigeration demand.

[0006] In order to achieve the above-mentioned purpose, according to one aspect of the present application, a control method for a data center cascade refrigeration system is provided, the data center cascade refrigeration system includes an evaporative hot and cold pipe refrigeration system, a chilled water refrigeration system and an indoor terminal, the indoor terminal is used to cool the indoor environment, the indoor terminal includes a first coil and a second coil, the first coil is connected to the chilled water refrigeration system, and the second coil is connected to the evaporative hot and cold pipe refrigeration system. The method includes: obtaining an outdoor wet-bulb temperature to obtain a first target temperature, obtaining an indoor return air temperature to obtain a second target temperature; calculating the difference between the first target temperature and the second target temperature to obtain a first target temperature difference; when the first target temperature is greater than a first preset temperature and the first target temperature difference is less than a first threshold, controlling the data center cascade refrigeration system to enter a first refrigeration mode, and the first refrigeration mode It is a mode in which only the chilled water refrigeration system is turned on, and the indoor terminal cools down the indoor environment through the first coil; when the first target temperature is less than or equal to the first preset temperature and greater than the second preset temperature and the first target temperature difference is greater than or equal to the first threshold, the data center cascade refrigeration system is controlled to enter the second refrigeration mode, and the second refrigeration mode is a mode in which the chilled water refrigeration system and the evaporative cold and hot pipe refrigeration system are turned on at the same time, and the indoor terminal cools down the indoor temperature through the first coil and the second coil; when the first target temperature is less than or equal to the second preset temperature and the first target temperature difference is greater than or equal to the second threshold, the data center cascade refrigeration system is controlled to enter the third refrigeration mode, and the third refrigeration mode is a mode in which only the evaporative cold and hot pipe refrigeration system is turned on, and the indoor terminal cools down the indoor temperature through the second coil, and the second threshold is greater than the first threshold.

[0007] Optionally, the chilled water refrigeration system includes a plate heat exchanger and a chiller, and controls the data center cascade refrigeration system to enter the second refrigeration mode, including: obtaining the chilled water return temperature, obtaining a third target temperature, calculating the difference between the first target temperature and the third target temperature, and obtaining the second target temperature difference; when the first target temperature is less than or equal to the first preset temperature and greater than the third preset temperature, the first target temperature difference is greater than or equal to the first threshold value, and the second target temperature difference is less than the third threshold value, controlling the data center cascade refrigeration system to enter the first sub-mode of the second refrigeration mode, the first sub-mode being a mode in which only the chiller is turned on in the chilled water refrigeration system, and the third threshold value is less than the first threshold value; when the first target temperature is less than or equal to the first preset temperature and greater than the third preset temperature, the first target temperature difference is greater than or equal to the first threshold value, and the second target temperature difference is less than the third threshold value When the third preset temperature is equal to or greater than the fourth preset temperature, the first target temperature difference is greater than or equal to the first threshold value, and the second target temperature difference is greater than or equal to the third threshold value, the data center cascade refrigeration system is controlled to enter the second sub-mode of the second refrigeration mode, and the second sub-mode is a mode in which the chiller and the plate heat exchanger in the chilled water refrigeration system are turned on at the same time; when the first target temperature is less than or equal to the fourth preset temperature and greater than the second preset temperature, the first target temperature difference is greater than or equal to the first threshold value, and the second target temperature difference is greater than or equal to the first threshold value, the data center cascade refrigeration system is controlled to enter the third sub-mode of the second refrigeration mode, and the third sub-mode is a mode in which only the plate heat exchanger in the chilled water refrigeration system is turned on.

[0008] Optionally, the chilled water refrigeration system also includes a compressor, a water pump and a water supply valve, which control the data center cascade refrigeration system to enter a first refrigeration mode, including: obtaining the load rate of the chiller, and adjusting the compressor frequency based on the load rate, wherein the compressor frequency is positively correlated with the load rate during the adjustment process; obtaining the loop pressure difference at the end of the pipeline, and adjusting the water pump frequency based on the loop pressure difference, wherein the water pump frequency is negatively correlated with the loop pressure difference during the adjustment process; adjusting the opening of the water supply valve based on the second target temperature, wherein the opening is positively correlated with the second target temperature during the adjustment process.

[0009] Optionally, the evaporative hot and cold pipe refrigeration system includes an evaporative condenser, a fluorine pump and an expansion valve, and controls the data center cascade refrigeration system to enter a third refrigeration mode, including: obtaining the condensing pressure of the evaporative condenser, and adjusting the fan frequency of the evaporative condenser according to the condensing pressure, wherein the fan frequency is positively correlated with the condensing pressure during the adjustment process; obtaining the front and rear pressure difference of the fluorine pump, and adjusting the fluorine pump frequency according to the front and rear pressure difference, wherein the fluorine pump frequency is negatively correlated with the front and rear pressure difference during the adjustment process; adjusting the opening of the expansion valve based on the second target temperature, wherein the opening is positively correlated with the second target temperature during the adjustment process.

[0010] Optionally, controlling the data center cascade refrigeration system to enter a second refrigeration mode includes: determining a first cooling load and a second cooling load based on a set temperature of the data center cascade refrigeration system and the outdoor wet-bulb temperature, the first cooling load being the portion of the total cooling load of the data center cascade refrigeration system borne by the chilled water refrigeration system, and the second cooling load being the portion of the total cooling load borne by the evaporative heat and cold pipe refrigeration system; controlling the evaporative heat and cold pipe refrigeration system to pre-cool the return air of the indoor terminal based on the second cooling load, and controlling the chilled water refrigeration system to supplement the return air of the indoor terminal based on at least the first cooling load, wherein, during the refrigeration process, the second cooling load is dynamically adjusted according to the outdoor temperature, and the first cooling load is adjusted in real time with changes in the total cooling load.

[0011] Optionally, the chilled water refrigeration system is controlled based on at least the first cooling load to provide supplementary cooling for the return air of the indoor terminal, including: when the data center cascade refrigeration system is in the first sub-mode, the operation of the chiller compressor is controlled according to the first cooling load, and the opening of the water supply valve is adjusted based on the deviation between the indoor supply air temperature and the set value; when the data center cascade refrigeration system is in the third sub-mode, the opening of the water supply valve is adjusted based on the deviation between the indoor supply air temperature and the set value.

[0012] Optionally, controlling the chilled water refrigeration system to provide supplementary cooling for the return air of the indoor terminal at least based on the first cooling load also includes: when the data center cascade refrigeration system is in the second sub-mode, obtaining the rated cooling load corresponding to the plate heat exchanger to obtain a third cooling load; calculating the difference between the first cooling load and the third cooling load to obtain a fourth cooling load, controlling the operation of the chiller compressor based on the fourth cooling load, and adjusting the opening of the water supply valve based on the deviation between the indoor supply air temperature and the set value.

[0013] According to another aspect of the present application, a control device for a data center cascade refrigeration system is provided. The data center cascade refrigeration system includes an evaporative hot and cold pipe refrigeration system, a chilled water refrigeration system and an indoor terminal. The indoor terminal is used to cool the indoor environment. The indoor terminal includes a first coil and a second coil. The first coil is connected to the chilled water refrigeration system, and the second coil is connected to the evaporative hot and cold pipe refrigeration system. The device includes: a first acquisition unit, used to acquire the outdoor wet-bulb temperature to obtain a first target temperature, and acquire the indoor return air temperature to obtain a second target temperature; a first calculation unit, used to calculate the difference between the first target temperature and the second target temperature to obtain a first target temperature difference; a first control unit, used to control the data center cascade refrigeration system to enter a first refrigeration mode when the first target temperature is greater than a first preset temperature and the first target temperature difference is less than a first threshold value. The first refrigeration mode is a mode in which only the chilled water refrigeration system is turned on, and the indoor terminal cools the indoor environment through the first coil; a second control unit, used to control the indoor terminal to cool the indoor environment when the first target temperature is less than or equal to the first preset temperature and greater than the second preset temperature difference. When the temperature is set and the first target temperature difference is greater than or equal to the first threshold, the data center cascade refrigeration system is controlled to enter the second refrigeration mode. The second refrigeration mode is a mode in which the chilled water refrigeration system and the evaporative cold and hot pipe refrigeration system are turned on at the same time, and the indoor terminal cools down the indoor temperature through the first coil and the second coil; a third control unit is used to control the data center cascade refrigeration system to enter the third refrigeration mode when the first target temperature is less than or equal to the second preset temperature and the first target temperature difference is greater than or equal to the second threshold. The third refrigeration mode is a mode in which only the evaporative cold and hot pipe refrigeration system is turned on, and the indoor terminal cools down the indoor temperature through the second coil, and the second threshold is greater than the first threshold.

[0014] According to another aspect of the present application, a computer-readable storage medium is provided, the computer-readable storage medium including a stored program, wherein when the program is executed, a device where the computer-readable storage medium is located is controlled to execute any one of the methods described above.

[0015] According to another aspect of the present application, a data center cascade cooling system is provided, comprising: one or more processors, a memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, and the one or more programs include methods for executing any one of the described methods.

[0016] By applying the technical solution of the present application, the control method of the cascade refrigeration system of the above-mentioned data center can automatically switch the operation mode of the refrigeration system by intelligently judging the outdoor wet-bulb temperature and the indoor return air temperature, so as to achieve the optimal energy efficiency ratio under different environmental conditions. At the same time, by accurately controlling the operating parameters of the chilled water refrigeration system and the evaporative heat and cold pipe refrigeration system, it is ensured that the indoor terminal can stably and efficiently provide cooling capacity, effectively reducing the refrigeration energy consumption of the data center and improving the operating efficiency and economy of the system. In addition, the control method can also dynamically adjust the operation strategy of the refrigeration system according to the changes in the actual cold load, further optimize the refrigeration effect and energy utilization, and provide strong technical support for the green and sustainable development of the data center. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A flow chart of a control method for a data center cascade cooling system provided in accordance with an embodiment of the present application is shown;

[0018] Figure 2 A control logic diagram of a data center cascade refrigeration system without a plate heat exchanger is shown according to an embodiment of the present application;

[0019] Figure 3 A control logic diagram of a data center cascade cooling system with a plate heat exchanger provided in accordance with an embodiment of the present application is shown;

[0020] Figure 4 A schematic structural diagram of a plateless heat exchanger for a data center cascade cooling system provided according to an embodiment of the present application is shown;

[0021] Figure 5 A schematic structural diagram of a data center cascade cooling system having a plate heat exchanger according to an embodiment of the present application is shown;

[0022] Figure 6 A structural block diagram of a control device for a data center cascade cooling system provided according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0023] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0024] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present application.

[0025] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present application described here. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0026] As introduced in the background technology, the prior art lacks a method for achieving low-consumption refrigeration when the temperature difference between the chilled water of the precision air conditioning in the data center and the temperature difference between the air conditioning supply and return air are greatly different. In order to solve the problem that the temperature difference between the wind side and the water side of the existing refrigeration system in the prior art is inconsistent, resulting in a short natural cooling time on the water side and more energy consumption to meet the refrigeration demand, the embodiments of the present application provide a control method, device, computer-readable storage medium and data center cascade refrigeration system for a data center.

[0027] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0028] In this embodiment, a control method for a data center cascade cooling system running on a mobile terminal, a computer terminal or a similar computing device is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0029] Figure 1 FIG. 1 is a flow chart of a control method for a data center cascade cooling system according to an embodiment of the present application. Figure 1 As shown, the method comprises the following steps:

[0030] Step S201, obtaining the outdoor wet-bulb temperature to obtain the first target temperature, obtaining the indoor return air temperature to obtain the second target temperature;

[0031] Specifically, the outdoor wet-bulb temperature and indoor return air temperature are obtained, wherein the outdoor wet-bulb temperature (first target temperature) is obtained by a temperature sensor installed outside the data center to determine whether outdoor natural cooling sources can be used for precooling. The indoor return air temperature (second target temperature) is obtained by a temperature sensor installed in the indoor air conditioning system to accurately control the indoor ambient temperature.

[0032] Step S202, calculating the difference between the first target temperature and the second target temperature to obtain a first target temperature difference;

[0033] Specifically, the target temperature difference is calculated by calculating the difference between the outdoor wet bulb temperature and the indoor return air temperature (the first target temperature difference) to determine the cooling mode to be adopted. This step determines whether the data center needs to introduce cold energy from the outside and the level of cold energy introduction based on the current environmental conditions.

[0034] Step S203, when the first target temperature is greater than the first preset temperature and the first target temperature difference is less than the first threshold, controlling the data center cascade refrigeration system to enter a first refrigeration mode, wherein the first refrigeration mode is a mode in which only the chilled water refrigeration system is turned on and the indoor terminal cools the indoor environment through the first coil;

[0035] Specifically, the cooling mode selects the first cooling mode: when the outdoor wet-bulb temperature is higher than the set first preset temperature (for example, 25°C), and the temperature difference between the indoor return air temperature and the outdoor wet-bulb temperature (the first target temperature difference) is less than the first threshold value (for example, 10°C), only the chilled water refrigeration system is turned on, and cooling is performed through the first coil (chilled water coil), and the chiller bears all the cooling load.

[0036] Step S204, when the first target temperature is less than or equal to the first preset temperature and greater than the second preset temperature and the first target temperature difference is greater than or equal to the first threshold, control the data center cascade refrigeration system to enter a second refrigeration mode, wherein the second refrigeration mode is a mode in which the chilled water refrigeration system and the evaporative cold and hot pipe refrigeration system are simultaneously turned on, and the indoor terminal cools the indoor temperature through the first coil and the second coil;

[0037] Specifically, the second cooling mode: when the outdoor wet-bulb temperature is lower than the first preset temperature but higher than the second preset temperature (for example, 11°C to 25°C), and the first target temperature difference is greater than or equal to the first threshold, the chilled water refrigeration system and the evaporative cold and hot pipe refrigeration system are turned on at the same time, the second coil (fluorine side coil) is pre-cooled, and the first coil is supplemented with cold, and the chiller and the evaporative cold and hot pipe system cooperate to bear the cooling load.

[0038] Step S205, when the first target temperature is less than or equal to the second preset temperature and the first target temperature difference is greater than or equal to the second threshold, the data center cascade refrigeration system is controlled to enter the third refrigeration mode, the third refrigeration mode is a mode in which only the evaporative cold and hot pipe refrigeration system is turned on, and the indoor terminal cools the indoor temperature through the second coil, and the second threshold is greater than the first threshold.

[0039] Specifically, the third cooling mode: when the outdoor wet-bulb temperature is lower than the second preset temperature (for example, below 11°C), and the first target temperature difference is greater than or equal to the second threshold (larger than the first threshold, for example, 24°C), only the evaporative cold and hot pipe refrigeration system is turned on, and independent natural cooling is performed through the second coil, thereby achieving completely natural cooling operation without starting the chiller.

[0040] The control logic of the above embodiment is as follows: Figure 2 As shown, the chilled water refrigeration system includes at least a chiller, a chilled water pump and a water coil (a first coil), and the evaporative hot and cold pipe refrigeration system includes at least an evaporative condenser, a fluorine pump and a fluorine coil (a second coil). The above-mentioned chilled water refrigeration system and the evaporative hot and cold pipe refrigeration system are both controlled by the outdoor wet-bulb temperature and the indoor return air temperature.

[0041] In the specific implementation, in a regional data center, it is assumed that the outdoor wet-bulb temperature is higher in summer and lower in winter. During the high temperature period in summer, the outdoor wet-bulb temperature is 30°C, the indoor return air temperature is 35°C, and the temperature difference is 5°C. In this case, according to the first cooling mode, the chilled water cooling system (including the chiller) will be turned on independently, and the first coil will be responsible for all cooling. This is because the outdoor temperature is too high, the pre-cooling effect is limited, and the temperature difference is insufficient, and the natural cold source cannot be effectively utilized.

[0042] In autumn, the outdoor wet-bulb temperature drops to 18°C, while the indoor return air temperature remains at 35°C, and the temperature difference widens to 17°C. At this time, according to the second cooling mode, the chilled water cooling system and the evaporative cooling and heat pipe cooling system are turned on at the same time. The fluorine coil first precools the return air to 28°C, and then the chilled water coil further cools it to the target temperature. The chiller and the evaporative cooling and heat pipe system work together to adjust the cooling output according to the actual indoor demand to achieve energy-saving effects.

[0043] In winter, the outdoor wet-bulb temperature further drops to 5°C, the indoor return air temperature is 35°C, and the temperature difference is 30°C. In this case, according to the third cooling mode, only the evaporative cold and hot pipe refrigeration system is turned on, and the fluorine coil operates independently to achieve natural cooling. At this time, the low temperature outdoor environment provides sufficient natural cold source for the data center, and there is no need to start the high-energy consumption chiller, which greatly reduces the energy consumption of the refrigeration system, thereby reducing the PUE value.

[0044] Through the above embodiments, it can be seen that the above-mentioned data center tiered refrigeration system and control method thereof can intelligently select the most suitable refrigeration mode according to different environmental conditions and indoor needs, maximize the use of natural cold sources, reduce energy consumption, and improve the energy efficiency ratio of the data center, while ensuring stable control of the indoor ambient temperature.

[0045] Through this embodiment, the outdoor wet-bulb temperature and indoor return air temperature are intelligently judged, and the operation mode of the refrigeration system is automatically switched to achieve the optimal energy efficiency ratio under different environmental conditions. At the same time, by accurately controlling the operating parameters of the chilled water refrigeration system and the evaporative cold and heat pipe refrigeration system, it is ensured that the indoor terminal can stably and efficiently provide cooling capacity, effectively reducing the refrigeration energy consumption of the data center and improving the operating efficiency and economy of the system. In addition, the control method can also dynamically adjust the operation strategy of the refrigeration system according to the changes in the actual cold load, further optimizing the refrigeration effect and energy utilization, and providing strong technical support for the green and sustainable development of the data center.

[0046] A plate heat exchanger is added to some chilled water systems. Considering the plate heat exchanger, the second refrigeration mode is further divided. In an optional implementation, the above step S204 includes:

[0047] Step S2041, obtaining the chilled water return temperature, obtaining a third target temperature, and calculating the difference between the first target temperature and the third target temperature to obtain a second target temperature difference;

[0048] Specifically, the activation condition of the second cooling mode is based on the difference between the outdoor wet-bulb temperature (first target temperature) and the indoor return air temperature (second target temperature), and the difference between the chilled water return temperature and the outdoor wet-bulb temperature. When the first target temperature is within a specific range (less than or equal to the first preset temperature but greater than the third preset temperature), and the first target temperature difference (i.e., the difference between the first target temperature and the second target temperature) reaches a preset first threshold, the system will enter the second cooling mode, and at this time, three sub-modes are further distinguished according to the second target temperature difference between the chilled water return temperature and the outdoor wet-bulb temperature.

[0049] Step S2042, when the first target temperature is less than or equal to the first preset temperature and greater than the third preset temperature, the first target temperature difference is greater than or equal to the first threshold value, and the second target temperature difference is less than the third threshold value, control the data center cascade refrigeration system to enter the first sub-mode of the second refrigeration mode, the first sub-mode being a mode in which only the chiller is turned on in the chilled water refrigeration system, and the third threshold value is less than the first threshold value;

[0050] Specifically, the first sub-mode (only the chiller is turned on in the chilled water system): when the second target temperature difference is less than the third threshold, it indicates that the plate heat exchanger has no cooling capacity. Therefore, the chilled water system only starts the chiller, and the plate heat exchanger does not participate in the operation, and the first coil is used for supplementary cooling, the second coil is used for precooling, and the first coil and the second coil cooperate for step cooling.

[0051] Step S2043, when the first target temperature is less than or equal to the third preset temperature and greater than the fourth preset temperature, the first target temperature difference is greater than or equal to the first threshold value, and the second target temperature difference is greater than or equal to the third threshold value, control the data center cascade refrigeration system to enter the second sub-mode of the second refrigeration mode, and the second sub-mode is a mode in which the chiller and the plate heat exchanger in the chilled water refrigeration system are simultaneously turned on;

[0052] Specifically, the second sub-mode (the chilled water system chiller and the plate heat exchanger are turned on at the same time): when the second target temperature difference is greater than or equal to the third threshold, the system believes that the outdoor conditions can partially support the efficient operation of the plate heat exchanger to use the natural cold source for pre-cooling. At this time, both the chiller and the plate heat exchanger will be started, and step cooling will be achieved through the coordinated work of the first coil and the second coil, in which the second coil uses the natural cold source for pre-cooling, and the first coil performs supplementary cooling according to the first cold load.

[0053] Step S2044, when the first target temperature is less than or equal to the fourth preset temperature and greater than the second preset temperature, the first target temperature difference is greater than or equal to the first threshold value, and the second target temperature difference is greater than or equal to the first threshold value, control the data center cascade refrigeration system to enter the third sub-mode of the second refrigeration mode, and the third sub-mode is a mode in which only the plate heat exchanger in the chilled water refrigeration system is turned on.

[0054] Specifically, the third sub-mode (only the plate heat exchanger of the chilled water system is turned on): when the first target temperature is further reduced (less than or equal to the third preset temperature and greater than the fourth preset temperature), and the second target temperature difference is greater than or equal to the first threshold, it indicates that the outdoor temperature is low enough and can be completely cooled by natural cold sources. Therefore, in this sub-mode, the chilled water system will only start the plate heat exchanger, turn off the chiller, and the first coil directly uses the natural cold source to cool the indoor air. The second coil is pre-cooled, and the first coil and the second coil cooperate to perform cascade cooling.

[0055] The control logic of the above embodiment is as follows: Figure 3 As shown, the above-mentioned chilled water refrigeration system may further include a plate heat exchanger (plate heat exchanger), and natural cooling is also introduced into the chilled water refrigeration system to further reduce energy consumption.

[0056] In a specific implementation, assume a data center, the current outdoor wet-bulb temperature is 21°C (first target temperature), the indoor return air temperature is 35°C (second target temperature), and the chilled water return temperature is 23°C (third target temperature).

[0057] Calculation of the first target temperature difference: 35°C - 21°C = 14°C, which is greater than the preset first threshold of 10°C, indicating that the indoor and outdoor temperature difference is sufficient to support entering the second cooling mode.

[0058] For the first sub-mode of the second cooling mode, if the second target temperature difference between the chilled water return temperature and the outdoor wet-bulb temperature is 2°C (23°C-21°C), which is less than the preset third threshold of 4°C, it indicates that the plate heat exchanger has no cooling capacity. Therefore, the chilled water system only starts the chiller, and the plate heat exchanger does not participate in the operation, and the first coil is used for supplementary cooling, the second coil is used for precooling, and the first coil and the second coil cooperate for cascade cooling.

[0059] If the outdoor wet-bulb temperature is 16°C, the second target temperature difference becomes 7°C (23°C-16°C), which is greater than the preset third threshold of 4°C. The system determines that the plate heat exchanger can partially support efficient natural cooling under the outdoor conditions and switches to the second sub-mode of the second cooling mode. At this time, the chiller and the plate heat exchanger of the chilled water system are started at the same time, and the first coil and the second coil cooperate to perform step cooling, making full use of the natural cold source while providing additional cooling through the first coil to ensure that the indoor temperature is stable within the target range.

[0060] If the outdoor wet-bulb temperature continues to drop to 12°C, the first target temperature meets the conditions for entering this sub-mode; the second target temperature difference becomes 11°C (23°C-12°C), which is greater than the preset first threshold of 10°C. The system determines that the plate heat exchanger under this outdoor condition can independently support efficient natural cooling, indicating that the outdoor temperature is sufficient to support full natural cooling, and enters the third sub-mode of the second cooling mode. In this sub-mode, the chilled water system only starts the plate heat exchanger, the chiller is completely shut down, and the first coil and the second coil cooperate for step cooling, making full use of the natural cold source while providing additional cooling through the first coil to ensure that the indoor temperature is stable within the target range.

[0061] Through the above control strategies and embodiments, the above data center cascade cooling system can intelligently select an operating mode that matches the current heat load under different outdoor temperature conditions, namely, the operation of the chiller alone, the joint operation of the chiller and the plate heat exchanger, and the operation of the plate heat exchanger alone, thereby ensuring the stability of the indoor ambient temperature while minimizing energy consumption and improving the overall energy efficiency of the refrigeration system.

[0062] In order to further reduce energy consumption in the first cooling mode, Figure 1As shown, in an optional implementation manner, the above step S203 includes:

[0063] Step S2031, obtaining the load rate of the chiller, and adjusting the compressor frequency of the compressor based on the load rate, wherein the compressor frequency is positively correlated with the load rate during the adjustment process;

[0064] Specifically, the compressor frequency regulation: obtain the load rate of the chiller, which reflects the proportion of the cooling load it is bearing to the maximum design cooling load. In the first cooling mode, the compressor frequency should be dynamically adjusted according to the load rate. When the load rate increases, the compressor frequency is increased to provide more cooling capacity; when the load rate decreases, the compressor frequency is reduced to avoid unnecessary power waste. This regulation mode ensures that the cooling output of the chiller is accurately matched to the current cooling load.

[0065] Step S2032, obtaining the loop pressure difference at the end of the pipeline, and adjusting the water pump frequency of the water pump based on the loop pressure difference, wherein the water pump frequency is negatively correlated with the loop pressure difference during the adjustment process;

[0066] Specifically, water pump frequency regulation: By monitoring the loop pressure difference at the end of the chilled water system pipeline, the flow of chilled water can be understood. During the regulation process, the water pump frequency is negatively correlated with the loop pressure difference. As the demand for chilled water in the system changes, the loop pressure difference will also change accordingly. When the pressure difference increases, it indicates that the demand for chilled water flow decreases. At this time, the water pump frequency should be reduced to reduce the supply of chilled water and avoid excessive circulation causing increased energy consumption; when the pressure difference decreases, it indicates that the system needs more chilled water flow, and the water pump frequency should be increased to ensure sufficient cooling capacity.

[0067] Step S2033, adjusting the opening of the water supply valve based on the second target temperature, wherein the opening is positively correlated with the second target temperature during the adjustment process.

[0068] Specifically, the water supply valve opening is adjusted: the water supply valve controls the amount of chilled water entering the first coil (chilled water coil) of the precision air conditioner. Based on the indoor return air temperature (second target temperature), the water supply valve opening is adjusted to accurately control the indoor temperature. During the adjustment process, the opening of the water supply valve is positively correlated with the second target temperature. When the indoor return air temperature rises, the water supply valve opening is increased to increase the chilled water flow rate and improve the cooling effect; when the indoor return air temperature drops, the water supply valve opening is reduced to reduce the chilled water flow rate to prevent overcooling.

[0069] In the specific implementation, the outdoor wet bulb temperature is set to 30°C and the indoor return air temperature is set to 35°C during the high temperature period in summer. According to the conditions of the first cooling mode, only the chilled water refrigeration system is started for cooling. Initially, the load rate of the chiller is 70% and the compressor frequency is set to 35Hz. As the heat load in the data center increases, the load rate of the chiller rises to 90%. The system automatically adjusts according to the load rate and increases the compressor frequency to about 45Hz to increase the cooling capacity.

[0070] At the same time, the loop pressure difference at the end of the chilled water system pipeline was monitored to be 0.8 bar, indicating that the chilled water circulation was relatively smooth. As the system cooling load increased, the demand for chilled water increased, causing the loop pressure difference to rise to 1.5 bar. At this time, the system automatically reduced the pump frequency and reduced the amount of chilled water circulation to avoid excessive water supply to the system and save electricity.

[0071] In terms of indoor temperature control, the indoor return air temperature is initially 35°C and the water supply valve opening is 70%. As the precision air conditioner operates, the indoor ambient temperature gradually drops to 34°C. Based on the feedback of the indoor return air temperature, the system reduces the water supply valve opening to about 60% to reduce the supply of chilled water and prevent the indoor temperature from being too low.

[0072] It can be seen from the above embodiments that the control method of the above-mentioned data center cascade refrigeration system in the first refrigeration mode realizes dynamic adjustment of the compressor frequency, water pump frequency and water supply valve opening according to actual needs, which not only ensures the cooling effect of the data center, but also effectively reduces energy consumption and improves the power utilization efficiency (PUE) of the system.

[0073] The above-mentioned embodiment can dynamically adjust the operating parameters of the chilled water refrigeration system according to the actual cooling load demand, further improving the energy efficiency of the system. It is suitable for scenarios where the number of servers in the data center varies and the cooling load demand fluctuates greatly, and can effectively cope with the rapid changes in the cooling load.

[0074] In order to further reduce energy consumption in the third cooling mode, Figure 1 As shown, in an optional implementation manner, the above step S205 includes:

[0075] Step S2051, obtaining the condensing pressure of the evaporative condenser, and adjusting the fan frequency of the evaporative condenser according to the condensing pressure, wherein the fan frequency is positively correlated with the condensing pressure during the adjustment process;

[0076] Specifically, evaporative condenser fan frequency regulation: The fan frequency regulation of the evaporative condenser is based on the condensing pressure feedback. The condensing pressure reflects the degree of condensation of the refrigerant in the condenser, as well as the cooling effect of the system. During the regulation process, the fan frequency is positively correlated with the condensing pressure. When the condensing pressure is high, the fan frequency is increased to improve the cooling efficiency and reduce the condensing pressure; when the condensing pressure is low, the fan frequency is reduced to prevent overcooling and save energy.

[0077] Step S2052, obtaining the front-to-back pressure difference of the fluorine pump, and adjusting the fluorine pump frequency of the fluorine pump according to the front-to-back pressure difference, wherein the fluorine pump frequency is negatively correlated with the front-to-back pressure difference during the adjustment process;

[0078] Specifically, fluorine pump frequency adjustment: fluorine pump frequency adjustment is based on the pressure difference before and after the fluorine pump. The pressure difference before and after the fluorine pump reflects the resistance to the flow of refrigerant in the fluorine system. During the adjustment process, the fluorine pump frequency is negatively correlated with the pressure difference before and after. When the pressure difference increases, it indicates that the flow of refrigerant in the system is blocked or the demand is reduced. At this time, the fluorine pump frequency should be reduced to reduce the circulation of refrigerant and prevent energy waste; when the pressure difference decreases, it indicates that the system needs more refrigerant flow, and the fluorine pump frequency should be increased to ensure sufficient cooling capacity.

[0079] Step S2053, adjusting the opening of the expansion valve based on the second target temperature, wherein the opening is positively correlated with the second target temperature during the adjustment process.

[0080] Specifically, the expansion valve opening is regulated: the expansion valve controls the amount of refrigerant entering the fluorine coil (the second coil). Based on the regulation of the indoor return air temperature (the second target temperature), the expansion valve opening is positively correlated with the second target temperature. When the indoor return air temperature rises, in order to enhance the cooling effect, the expansion valve opening needs to be increased to increase the refrigerant flow rate; when the indoor return air temperature drops, in order to avoid overcooling, the expansion valve opening should be reduced to reduce the refrigerant flow rate.

[0081] In the specific implementation, it is assumed that under cold winter conditions, the outdoor wet bulb temperature is 5°C and the indoor return air temperature is 35°C. The system judges to enter the third cooling mode, and only the evaporative cold and hot pipe refrigeration system operates independently. Initially, the condensing pressure of the evaporative condenser is 15 bar and the fan frequency is set to 40 Hz. As the outdoor temperature further decreases, the condensing pressure drops to 12 bar. At this time, the system automatically adjusts and reduces the fan frequency to about 30 Hz to reduce energy consumption.

[0082] The initial monitoring of the pressure difference before and after the fluorine pump is 1 bar, and the fluorine pump frequency is 30Hz. As the system runs, due to the smooth circulation of refrigerant, the pressure difference drops to 0.7bar, and the system automatically increases the fluorine pump frequency to about 35Hz to ensure that there is enough refrigerant flow in the fluorine coil to meet the indoor cooling needs.

[0083] The indoor return air temperature (second target temperature) is initially 35°C, and the expansion valve opening is 70%. As the evaporative heat and cold pipe refrigeration system operates, the indoor temperature gradually drops to 33°C. Based on the indoor return air temperature feedback, the system reduces the expansion valve opening to about 60% to control the cooling speed and prevent the indoor temperature from dropping below the set value too quickly.

[0084] Through this embodiment, it can be seen that the above-mentioned data center cascade refrigeration system realizes dynamic adjustment of the evaporative condenser fan frequency, fluorine pump frequency and expansion valve opening in the third refrigeration mode through a fine control strategy, which not only effectively utilizes the outdoor natural cold source, but also ensures the precise control of the indoor ambient temperature, while achieving energy conservation and improving the overall energy efficiency of the system. This method makes full use of the efficient refrigeration characteristics of the evaporative heat pipe refrigeration system in a low temperature environment, and can significantly reduce the refrigeration energy consumption of the data center when the outdoor temperature is low, and is particularly suitable for time periods with good natural cooling conditions such as night or winter.

[0085] In order to further reduce energy consumption in the above second cooling mode, Figure 2 As shown, in an optional implementation manner, the above step S204 further includes:

[0086] Step S2045, based on the set temperature of the data center cascade refrigeration system and the outdoor wet-bulb temperature, determine the first cooling load and the second cooling load, the first cooling load being the portion of the total cooling load of the data center cascade refrigeration system borne by the chilled water refrigeration system, and the second cooling load being the portion of the total cooling load borne by the evaporative heat and cold pipe refrigeration system;

[0087] Specifically, based on the target setting temperature of the data center's cascade cooling system (such as the control target of the indoor ambient temperature) and the outdoor wet-bulb temperature (for example, corresponding to the outdoor wet-bulb temperature, the evaporative hot and cold pipe refrigeration system bears 40% of the cooling load and the chilled water refrigeration system bears 60% of the cooling load), the first cooling load (borne by the chilled water refrigeration system) and the second cooling load (borne by the evaporative hot and cold pipe refrigeration system) under the total cooling load are calculated.

[0088] Step S2046, based on the second cooling load, control the evaporative heat and cold pipe refrigeration system to pre-cool the return air of the indoor terminal, and at least based on the first cooling load, control the chilled water refrigeration system to supplement the return air of the indoor terminal, wherein, during the refrigeration process, the second cooling load is dynamically adjusted according to the outdoor wet-bulb temperature, and the first cooling load is adjusted in real time with the change of the total cooling load.

[0089] Specifically, as the heat load of the data center changes, the total cooling load will also change accordingly. The first cooling load needs to be adjusted in real time to match the change in the total cooling load; the second cooling load is dynamically adjusted according to the outdoor wet-bulb temperature to ensure full utilization of the natural cooling source.

[0090] It is understandable that in the second cooling mode, the evaporative heat pipe refrigeration system (fluorine-containing coil) is responsible for pre-cooling the return air of the indoor terminal (such as precision air conditioning), first lowering the return air temperature and reducing the need for subsequent cooling. The chilled water refrigeration system (including chilled water coil) performs supplementary cooling according to the first cooling load, further reducing the pre-cooled return air temperature to the target temperature. This cascade cooling strategy effectively reduces the energy consumption of the entire system and improves the power utilization efficiency (PUE) by first using a natural cold source for pre-cooling and then using energy-intensive mechanical refrigeration for supplementary cooling.

[0091] In the specific implementation, assuming that the indoor air supply temperature of the data center is set to 23°C, the current indoor return air temperature is 35°C, and the outdoor wet-bulb temperature is 18°C, the system determines to enter the second cooling mode. Corresponding to the outdoor wet-bulb temperature, the evaporative cold and hot pipe refrigeration system bears 50% of the cooling load, and the chilled water refrigeration system bears 50% of the cooling load. According to the current heat load, the total cooling load is calculated to be 100kW, the first cooling load is 50kW, and the second cooling load is 50kW.

[0092] Pre-cooling stage: The evaporative cold and hot pipe refrigeration system is started, and the fluorine coil pre-cools the indoor return air to 29°C by adjusting the opening of its expansion valve, assuming a cooling load of 50kW.

[0093] Supplementary cooling stage: The chilled water refrigeration system opens the chilled water regulating valve according to the outlet air temperature signal of the second coil, and starts the chilled water system to supplement the pre-cooled air, so that the indoor return air temperature finally reaches the target temperature of 23℃.

[0094] As the data center operates, the heat load may change. Assuming that the heat load increases to 120kW after a period of time, corresponding to the outdoor wet bulb temperature and total cooling load, the second cooling load may be adjusted to about 55kW to adapt to the slight change in outdoor temperature conditions, and the first cooling load is adjusted to about 65kW in real time.

[0095] Through the above embodiments, the data center cascade cooling system realizes an efficient and energy-saving cooling process in the second cooling mode by dynamically allocating the cooling load and the coordinated control strategy of pre-cooling and supplementary cooling. It not only effectively utilizes the natural cold source, but also ensures the precise control of the indoor ambient temperature, while reducing the energy consumption of the entire system and further improving the power utilization efficiency (PUE).

[0096] In order to achieve accurate cooling load distribution, in an optional implementation, the above step S2046 includes:

[0097] Step S20461, when the data center cascade refrigeration system is in the first sub-mode, controlling the operation of the chiller compressor according to the first cooling load, and adjusting the opening of the water supply valve based on the deviation between the indoor supply air temperature and the set value;

[0098] Specifically, in the first sub-mode of the second cooling mode, only the chiller is turned on and the chilled water system runs directly. At this time, the control system adjusts the operating state of the chiller compressor according to the first cooling load (i.e., the cooling load part borne by the chilled water refrigeration system) to ensure that the system can meet the cooling demand. At the same time, based on the deviation between the indoor supply air temperature and the set target temperature (such as 23°C), the opening of the water supply valve is dynamically adjusted to accurately control the cooling effect. If the deviation shows that the indoor supply air temperature is higher than the set value, the water supply valve opening is increased, the chilled water flow rate is increased, and the supplementary cooling capacity is improved; conversely, the water supply valve opening is reduced and the flow rate is reduced to avoid overcooling.

[0099] Step S20462: When the data center cascade cooling system is in the third sub-mode, the opening of the water supply valve is adjusted based on the deviation of the indoor air supply temperature from the set value.

[0100] Specifically, in the third sub-mode of the second cooling mode, the chiller is turned off, only the plate heat exchanger is turned on, and cooling is performed using a natural cold source. At this time, the control system adjusts the opening of the water supply valve based entirely on the deviation between the indoor air supply temperature and the set target temperature to match the temperature control requirements of the indoor environment under natural cooling conditions. The deviation-based adjustment strategy is also applicable to ensuring that the indoor temperature is stable within the set range, but unlike the first sub-mode, the compressor control is not involved here.

[0101] In the above embodiment, assuming that it is autumn, the outdoor wet-bulb temperature is 20°C, and the indoor return air temperature is 35°C, the system determines to enter the first sub-mode of the second cooling mode, that is, only the chiller is turned on.

[0102] During the initial setting, the system calculates that the current total cooling load is 100kW. According to the outdoor wet-bulb temperature, the chilled water cooling system needs to bear the first cooling load of 60kW. The chiller compressor runs to provide basic cooling capacity. The indoor supply air temperature is 25℃, which is 23℃ higher than the set target temperature. The system detects a deviation of 2℃ and automatically increases the water supply valve opening, increases the compressor cooling capacity, increases the chilled water flow, and improves the supplementary cooling effect until the indoor supply air temperature drops to the target range.

[0103] After a period of time, the outdoor wet-bulb temperature continued to drop to 11°C. The system entered the third sub-mode of the second cooling mode based on the temperature difference. At this time, the chiller was turned off, and only the plate heat exchanger was running, using the natural cold source for cooling. The indoor air supply temperature was adjusted to 24°C with a deviation of 1°C. The system directly adjusted the water supply valve opening based on this deviation, reducing the compressor cooling capacity to ensure that the indoor ambient temperature can be stabilized within the set range through natural cooling.

[0104] Through this embodiment, in different sub-modes, the data center cascade refrigeration system can achieve precise control of the supplementary cooling process of the chilled water refrigeration system by adjusting the operating status of the compressor and dynamically adjusting the opening of the water supply valve. This not only ensures the stability of the indoor ambient temperature, but also achieves efficient operation of the system and energy conservation by intelligently matching the cooling requirements in different modes.

[0105] In order to achieve accurate cooling load distribution, in an optional implementation, the above step S2046 further includes:

[0106] Step S20463, when the data center cascade cooling system is in the second sub-mode, obtaining a rated cooling load corresponding to the plate heat exchanger to obtain a third cooling load;

[0107] Specifically, in the second sub-mode, the system not only has a chilled water refrigeration system involved in cooling, but also a plate heat exchanger (plate heat exchanger) that uses a natural cold source for pre-cooling. Therefore, it is necessary to determine the rated cooling load (third cooling load) corresponding to the plate heat exchanger, which reflects the maximum cooling load that the plate heat exchanger can bear at the current outdoor temperature.

[0108] Step S20464, calculate the difference between the first cooling load and the third cooling load to obtain a fourth cooling load, control the operation of the chiller compressor based on the fourth cooling load, and adjust the opening of the water supply valve based on the deviation between the indoor supply air temperature and the set value.

[0109] Specifically, by comparing the first cooling load (the cooling load borne by the chilled water refrigeration system) with the third cooling load, the fourth cooling load, that is, the cooling load that the chilled water refrigeration system actually needs to bear, can be calculated, thereby determining the operating state of the chiller compressor and adjusting the opening of the water supply valve to achieve accurate matching with the heat load. Compressor operation and water supply valve opening adjustment: Based on the fourth cooling load, the operating state of the chiller compressor is adjusted to ensure that sufficient cooling can be provided to meet the remaining cooling load requirements. At the same time, the opening of the water supply valve is adjusted according to the deviation between the indoor supply air temperature and the set target temperature. A large deviation indicates that the indoor temperature is too high and the chilled water flow rate needs to be increased to improve the cooling effect; otherwise, the chilled water flow rate is reduced to avoid overcooling.

[0110] In the specific implementation, assuming that during the winter transition period, the outdoor wet-bulb temperature is 15°C and the indoor return air temperature is 35°C, the system determines to enter the second sub-mode of the second cooling mode, that is, the chilled water refrigeration system and the evaporative hot and cold pipe refrigeration system operate at the same time, and the chiller and plate exchanger are jointly turned on.

[0111] The current total cooling load is 120kW. According to the set temperature and outdoor temperature conditions, the chilled water refrigeration system needs to bear the first cooling load of 35kW. At this time, the rated cooling load corresponding to the plate heat exchanger is about 25kW (the third cooling load), and the fourth cooling load is calculated to be 10kW, indicating that the chiller side of the chilled water refrigeration system actually needs to provide 10kW of cooling capacity to supplement the cooling.

[0112] At the initial setting, the indoor air supply temperature is 24°C, which is 23°C higher than the set target temperature, and the system detects a deviation of 1°C. At this time, the water supply valve opening increases, increasing the cooling capacity of the chiller compressor to increase the chilled water flow and improve the supplementary cooling effect until the indoor air supply temperature drops to the target range.

[0113] As the outdoor temperature decreases, the rated cooling load of the plate heat exchanger may increase to 30kW, and the fourth cooling load is recalculated to 5kW. The indoor air supply temperature is adjusted to 22℃, with a deviation of 1℃. The system adjusts the operating state of the chiller compressor according to the new fourth cooling load, reduces the compressor cooling capacity, and ensures that the chilled water cooling system and the evaporative cold and hot pipe cooling system work together to meet the cooling needs and achieve efficient use of energy.

[0114] It can be seen from the above embodiments that the control strategy of the data center cascade refrigeration system in the second sub-mode, through accurate calculation and dynamic adjustment of the cooling load distribution, the operating status of the chiller compressor and the opening of the water supply valve, effectively realizes the high efficiency and energy saving of the chilled water refrigeration system for supplementary cooling of the indoor terminal return air, while ensuring the stable control of the internal ambient temperature of the data center.

[0115] In the above embodiments, the present application is respectively described according to different control modes of two chilled water refrigeration systems with plate exchange and without plate exchange. The following is a description of two different chilled water refrigeration systems in conjunction with the drawings in the embodiments of the present application. Figure 4 As shown in the figure, the plate-less chilled water refrigeration system, in which the chilled water flows from the chiller to the cold storage tank through a water pump, and then supplies cooling to the air conditioner connected to the cold storage tank. A flow meter is installed between the chiller and the cold storage tank to monitor the flow of chilled water, and the return water loop pressure is monitored and adjusted through an automatic constant pressure water replenishment device. In addition, a butterfly valve and an electric regulating valve are installed between the cold storage tank and the air conditioner to control the chilled water in the water coil. Figure 5 As shown, in Figure 4Based on the plate-free chilled water refrigeration system shown in the figure, a plate heat exchanger is installed on the basis of the chiller to cool the chilled water by taking advantage of the ambient temperature difference, further reducing energy consumption. Figure 4 and Figure 5 As shown, an evaporative heat and cold pipe refrigeration system, in which the fluorine refrigerant flows from the evaporative condenser to the fluorine coil through a fluorine pump, and an electronic expansion valve and a ball valve are installed between the evaporative condenser and the fluorine coil to control the flow of the fluorine refrigerant, thereby achieving precise regulation of the cooling load. In this embodiment, the data center cascade refrigeration system combines the evaporative heat and cold pipe refrigeration system with the chilled water refrigeration system. The fluorine coil first cools the return air of the air conditioner to reduce the temperature difference between the return air and the chilled water, and then cools the return air of the air conditioner through the water coil, thereby ensuring the supply air temperature and reducing the overall energy consumption.

[0116] It should be noted that the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and that, although a logical order is shown in the flowcharts, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0117] The embodiment of the present application also provides a control device for a data center cascade refrigeration system. It should be noted that the control device for a data center cascade refrigeration system of the embodiment of the present application can be used to execute the control method for a data center cascade refrigeration system provided in the embodiment of the present application. The device is used to implement the above-mentioned embodiments and preferred implementation modes, and those that have been explained will not be repeated. As used below, the term "module" can be a combination of software and / or hardware that implements a predetermined function. Although the devices described in the following embodiments are preferably implemented in software, the implementation of hardware, or a combination of software and hardware, is also possible and conceivable.

[0118] The following is an introduction to the control device of the data center cascade cooling system provided in the embodiment of the present application.

[0119] Figure 6 1 is a structural block diagram of a control device for a data center cascade cooling system according to an embodiment of the present application. Figure 6 As shown, the device comprises:

[0120] The first acquisition unit 10 is used to acquire the outdoor wet-bulb temperature to obtain the first target temperature, and acquire the indoor return air temperature to obtain the second target temperature;

[0121] A first calculation unit 20 is used to calculate the difference between the first target temperature and the second target temperature to obtain a first target temperature difference;

[0122] The first control unit 30 is used to control the data center cascade refrigeration system to enter a first refrigeration mode when the first target temperature is greater than the first preset temperature and the first target temperature difference is less than the first threshold value. The first refrigeration mode is a mode in which only the chilled water refrigeration system is turned on and the indoor terminal cools the indoor environment through the first coil;

[0123] A second control unit 40 is used to control the data center cascade refrigeration system to enter a second refrigeration mode when the first target temperature is less than or equal to the first preset temperature and greater than the second preset temperature and the first target temperature difference is greater than or equal to the first threshold value. The second refrigeration mode is a mode in which the chilled water refrigeration system and the evaporative cold and hot pipe refrigeration system are turned on at the same time, and the indoor terminal cools the indoor temperature through the first coil and the second coil;

[0124] The third control unit 50 is used to control the data center cascade refrigeration system to enter a third refrigeration mode when the first target temperature is less than or equal to the second preset temperature and the first target temperature difference is greater than or equal to the second threshold value. The third refrigeration mode is a mode in which only the evaporative cold and hot pipe refrigeration system is turned on, and the indoor terminal cools down the indoor temperature through the second coil, and the second threshold value is greater than the first threshold value.

[0125] Through this embodiment, the outdoor wet-bulb temperature and indoor return air temperature are intelligently judged, and the operation mode of the refrigeration system is automatically switched to achieve the optimal energy efficiency ratio under different environmental conditions. At the same time, by accurately controlling the operating parameters of the chilled water refrigeration system and the evaporative cold and heat pipe refrigeration system, it is ensured that the indoor terminal can stably and efficiently provide cooling capacity, effectively reducing the refrigeration energy consumption of the data center and improving the operating efficiency and economy of the system. In addition, the control method can also dynamically adjust the operation strategy of the refrigeration system according to the changes in the actual cold load, further optimizing the refrigeration effect and energy utilization, and providing strong technical support for the green and sustainable development of the data center.

[0126] A plate heat exchanger is added to some chilled water systems. Considering the plate heat exchanger, the second refrigeration mode is further divided. In an optional implementation, the second control unit includes:

[0127] A first acquisition module is used to acquire the chilled water return temperature, obtain a third target temperature, and calculate the difference between the first target temperature and the third target temperature to obtain a second target temperature difference;

[0128] A first control module is used to control the data center cascade refrigeration system to enter a first sub-mode of the second refrigeration mode when the first target temperature is less than or equal to the first preset temperature and greater than a third preset temperature, the first target temperature difference is greater than or equal to the first threshold value, and the second target temperature difference is less than the third threshold value, wherein the first sub-mode is a mode in which only the chiller is turned on in the chilled water refrigeration system, and the third threshold value is less than the first threshold value;

[0129] A second control module is used to control the data center cascade refrigeration system to enter a second sub-mode of the second refrigeration mode when the first target temperature is less than or equal to the third preset temperature and greater than a fourth preset temperature, the first target temperature difference is greater than or equal to the first threshold value, and the second target temperature difference is greater than or equal to the third threshold value, wherein the second sub-mode is a mode in which the chiller and the plate heat exchanger in the chilled water refrigeration system are simultaneously turned on;

[0130] The third control module is used to control the data center cascade refrigeration system to enter the third sub-mode of the second refrigeration mode when the first target temperature is less than or equal to the fourth preset temperature and greater than the second preset temperature, the first target temperature difference is greater than or equal to the first threshold value, and the second target temperature difference is greater than or equal to the first threshold value. The third sub-mode is a mode in which only the plate heat exchanger in the chilled water refrigeration system is turned on.

[0131] In order to further reduce energy consumption in the first cooling mode, in an optional implementation, the first control unit includes:

[0132] a second acquisition module, configured to acquire a load rate of the chiller, and adjust a compressor frequency of the compressor based on the load rate, wherein the compressor frequency is positively correlated with the load rate during the adjustment process;

[0133] A third acquisition module is used to acquire the loop pressure difference at the end of the pipeline, and adjust the water pump frequency of the water pump based on the loop pressure difference, wherein the water pump frequency is negatively correlated with the loop pressure difference during the adjustment process;

[0134] The fourth control module is used to adjust the opening of the water supply valve based on the second target temperature, wherein the opening is positively correlated with the second target temperature during the adjustment process.

[0135] In order to further reduce energy consumption in the third refrigeration mode, in an optional implementation, the third control unit includes:

[0136] a fourth acquisition module, configured to acquire the condensing pressure of the evaporative condenser, and adjust the fan frequency of the evaporative condenser according to the condensing pressure, wherein the fan frequency is positively correlated with the condensing pressure during the adjustment process;

[0137] a fifth acquisition module, for acquiring the front-rear pressure difference of the fluorine pump, and adjusting the fluorine pump frequency of the fluorine pump according to the front-rear pressure difference, wherein the fluorine pump frequency is negatively correlated with the front-rear pressure difference during the adjustment process;

[0138] The fifth control module is used to adjust the opening of the expansion valve based on the second target temperature, wherein the opening is positively correlated with the second target temperature during the adjustment process.

[0139] In order to further reduce energy consumption in the second cooling mode, in an optional implementation, the second control unit further includes:

[0140] A first determination module is used to determine a first cooling load and a second cooling load based on a set temperature of the data center cascade refrigeration system and a corresponding outdoor wet-bulb temperature, wherein the first cooling load is a portion of the total cooling load of the data center cascade refrigeration system borne by the chilled water refrigeration system, and the second cooling load is a portion of the total cooling load borne by the evaporative cold and heat pipe refrigeration system;

[0141] The sixth control module is used to control the evaporative heat and cold pipe refrigeration system to pre-cool the return air of the indoor terminal based on the second cooling load, and to control the chilled water refrigeration system to supplement the return air of the indoor terminal based at least on the first cooling load, wherein during the refrigeration process, the second cooling load is dynamically adjusted according to the outdoor wet-bulb temperature, and the first cooling load is adjusted in real time with the changes in the total cooling load and the second cooling load.

[0142] In order to achieve accurate cooling load distribution, in an optional implementation, the sixth control module includes:

[0143] A first control submodule, configured to control the operation of the chiller compressor according to the first cooling load and adjust the opening of the water supply valve based on the deviation between the indoor air supply temperature and the set value when the data center cascade refrigeration system is in the first submode;

[0144] The second control submodule is used to adjust the opening of the water supply valve based on the deviation between the indoor air supply temperature and the set value when the data center cascade cooling system is in the third submode.

[0145] In order to achieve accurate cold load distribution, in an optional implementation, the sixth control module further includes:

[0146] An acquisition submodule, used for acquiring a rated cooling load corresponding to the plate heat exchanger to obtain a third cooling load when the data center cascade cooling system is in the second submode;

[0147] The calculation submodule is used to calculate the difference between the first cooling load and the third cooling load to obtain a fourth cooling load, control the operation of the chiller compressor based on the fourth cooling load, and adjust the opening of the water supply valve based on the deviation between the indoor supply air temperature and the set value.

[0148] The control device of the data center cascade cooling system includes a processor and a memory. The first acquisition unit, the first calculation unit, the first control unit, the second control unit and the third control unit are all stored in the memory as program units, and the processor executes the program units stored in the memory to implement corresponding functions. The modules are all located in the same processor; or, the modules are located in different processors in any combination.

[0149] The processor includes a kernel, which calls the corresponding program unit from the memory. One or more kernels can be set, and the communication efficiency can be improved by adjusting the kernel parameters.

[0150] The memory may include non-permanent memory in a computer-readable medium, random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM, and the memory includes at least one memory chip.

[0151] An embodiment of the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium includes a stored program, wherein when the program is executed, the device where the computer-readable storage medium is located is controlled to execute the control method of the data center cascade refrigeration system.

[0152] An embodiment of the present invention provides a processor, and the processor is used to run a program, wherein the control method of the data center cascade refrigeration system is executed when the program is run.

[0153] An embodiment of the present invention provides a communication system, which includes a primary communication domain, a secondary communication domain processor, a memory, and a program stored in the memory and executable on the processor. When the processor executes the program, at least the steps of a control method for a data center cascade refrigeration system are implemented.

[0154] The present application also provides a computer program product, which, when executed on a data processing device, is suitable for executing a program for initializing at least the steps of a control method for a data center cascade cooling system.

[0155] Obviously, those skilled in the art should understand that the above modules or steps of the present invention can be implemented by a general computing device, they can be concentrated on a single computing device, or distributed on a network composed of multiple computing devices, they can be implemented by a program code executable by a computing device, so that they can be stored in a storage device and executed by the computing device, and in some cases, the steps shown or described can be executed in a different order than here, or they can be made into individual integrated circuit modules, or multiple modules or steps therein can be made into a single integrated circuit module for implementation. Thus, the present invention is not limited to any specific combination of hardware and software.

[0156] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0157] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0158] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0159] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0160] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0161] The memory may include non-permanent memory in a computer-readable medium, random access memory (RAM) and / or non-volatile memory in the form of read-only memory (ROM) or flash RAM. The memory is an example of a computer-readable medium.

[0162] Computer readable media include permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. Information can be computer readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, magnetic disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer readable media does not include temporary computer readable media (transitory media), such as modulated data signals and carrier waves.

[0163] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0164] From the above description, it can be seen that the above embodiments of the present application achieve the following technical effects:

[0165] The control method and device of the data center cascade refrigeration system of the present application can intelligently judge the outdoor wet-bulb temperature and the indoor return air temperature, automatically switch the operation mode of the refrigeration system, and achieve the optimal energy efficiency ratio under different environmental conditions. At the same time, by accurately controlling the operating parameters of the chilled water refrigeration system and the evaporative cold and heat pipe refrigeration system, it is ensured that the indoor terminal can provide cooling capacity stably and efficiently, effectively reducing the cooling energy consumption of the data center and improving the operating efficiency and economy of the system. In addition, the control method can also dynamically adjust the operation strategy of the refrigeration system according to the changes in the actual cold load, further optimize the refrigeration effect and energy utilization, and provide strong technical support for the green and sustainable development of the data center.

[0166] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A control method for a data center cascade cooling system, characterized in that: The data center cascade refrigeration system includes an evaporative cold and hot pipe refrigeration system, a chilled water refrigeration system and an indoor terminal, the indoor terminal is used to cool the indoor environment, the indoor terminal includes a first coil and a second coil, the first coil is connected to the chilled water refrigeration system, and the second coil is connected to the evaporative cold and hot pipe refrigeration system, the method includes: Obtain the outdoor wet-bulb temperature to obtain the first target temperature, obtain the indoor return air temperature to obtain the second target temperature; Calculating the difference between the first target temperature and the second target temperature to obtain a first target temperature difference; When the first target temperature is greater than the first preset temperature and the first target temperature difference is less than the first threshold, the data center cascade refrigeration system is controlled to enter a first refrigeration mode, wherein the first refrigeration mode is a mode in which only the chilled water refrigeration system is turned on and the indoor terminal cools the indoor environment through the first coil; When the first target temperature is less than or equal to the first preset temperature and greater than the second preset temperature and the first target temperature difference is greater than or equal to the first threshold, the data center cascade refrigeration system is controlled to enter a second refrigeration mode, wherein the second refrigeration mode is a mode in which the chilled water refrigeration system and the evaporative cold and hot pipe refrigeration system are simultaneously turned on, and the indoor terminal cools the indoor temperature through the first coil and the second coil; When the first target temperature is less than or equal to the second preset temperature and the first target temperature difference is greater than or equal to the second threshold, the data center cascade refrigeration system is controlled to enter a third refrigeration mode, wherein the third refrigeration mode is a mode in which only the evaporative hot and cold pipe refrigeration system is turned on, and the indoor terminal cools down the indoor temperature through the second coil, and the second threshold is greater than the first threshold.

2. The method according to claim 1, characterized in that: The chilled water refrigeration system includes a plate heat exchanger and a chiller, and controlling the data center cascade refrigeration system to enter a second refrigeration mode includes: Acquire the chilled water return temperature to obtain a third target temperature, calculate the difference between the first target temperature and the third target temperature to obtain a second target temperature difference; When the first target temperature is less than or equal to the first preset temperature and greater than the third preset temperature, the first target temperature difference is greater than or equal to the first threshold value, and the second target temperature difference is less than the third threshold value, the data center cascade refrigeration system is controlled to enter the first sub-mode of the second refrigeration mode, the first sub-mode is a mode in which only the chiller is turned on in the chilled water refrigeration system, and the third threshold value is less than the first threshold value; When the first target temperature is less than or equal to the third preset temperature and greater than the fourth preset temperature, the first target temperature difference is greater than or equal to the first threshold value, and the second target temperature difference is greater than or equal to the third threshold value, the data center cascade refrigeration system is controlled to enter a second sub-mode of the second refrigeration mode, and the second sub-mode is a mode in which the chiller and the plate heat exchanger in the chilled water refrigeration system are turned on at the same time; When the first target temperature is less than or equal to the fourth preset temperature and greater than the second preset temperature, the first target temperature difference is greater than or equal to the first threshold, and the second target temperature difference is greater than or equal to the first threshold, the data center cascade refrigeration system is controlled to enter the third sub-mode of the second refrigeration mode, and the third sub-mode is a mode in which only the plate heat exchanger in the chilled water refrigeration system is turned on.

3. The method according to claim 2, characterized in that The chilled water refrigeration system further includes a compressor, a water pump and a water supply valve, and controls the data center cascade refrigeration system to enter a first refrigeration mode, including: Acquiring a load factor of the chiller, and adjusting a compressor frequency of the compressor based on the load factor, wherein the compressor frequency is positively correlated with the load factor during the adjustment process; Acquiring a loop pressure difference at an end of the pipeline, and adjusting a water pump frequency of the water pump based on the loop pressure difference, wherein the water pump frequency is negatively correlated with the loop pressure difference during the adjustment process; The opening degree of the water supply valve is adjusted based on the second target temperature, wherein the opening degree is positively correlated with the second target temperature during the adjustment process.

4. The method according to claim 2, characterized in that: The evaporative cold and hot pipe refrigeration system includes an evaporative condenser, a fluorine pump and an expansion valve, and controls the data center cascade refrigeration system to enter the third refrigeration mode, including: Acquiring a condensing pressure of the evaporative condenser, and adjusting a fan frequency of the evaporative condenser according to the condensing pressure, wherein the fan frequency is positively correlated with the condensing pressure during the adjustment process; Obtaining a front-to-rear pressure difference of the fluorine pump, and adjusting a fluorine pump frequency of the fluorine pump according to the front-to-rear pressure difference, wherein during the adjustment process, the fluorine pump frequency is negatively correlated with the front-to-rear pressure difference; The opening degree of the expansion valve is adjusted based on the second target temperature, wherein the opening degree is positively correlated with the second target temperature during the adjustment process.

5. The method according to claim 3, characterized in that: Controlling the data center cascade refrigeration system to enter a second refrigeration mode includes: Based on the set temperature of the data center cascade refrigeration system and the outdoor wet-bulb temperature, determining a first cooling load and a second cooling load, wherein the first cooling load is the portion of the total cooling load of the data center cascade refrigeration system borne by the chilled water refrigeration system, and the second cooling load is the portion of the total cooling load borne by the evaporative cold and heat pipe refrigeration system; Based on the second cooling load, the evaporative heat and cold pipe refrigeration system is controlled to pre-cool the return air of the indoor terminal, and based at least on the first cooling load, the chilled water refrigeration system is controlled to supplement the return air of the indoor terminal, wherein, during the refrigeration process, the second cooling load is dynamically adjusted according to the outdoor wet-bulb temperature, and the first cooling load is adjusted in real time with the changes in the total cooling load and the second cooling load.

6. The method according to claim 5, characterized in that Controlling the chilled water refrigeration system to provide supplementary cooling for the return air of the indoor terminal based at least on the first cooling load includes: When the data center cascade cooling system is in the first sub-mode, the chiller compressor is controlled to operate according to the first cooling load, and the opening of the water supply valve is adjusted based on the deviation between the indoor supply air temperature and the set value; When the data center cascade cooling system is in the third sub-mode, the opening degree of the water supply valve is adjusted based on the deviation of the indoor supply air temperature from the set value.

7. The method according to claim 5, characterized in that Controlling the chilled water refrigeration system to provide supplementary cooling for the return air of the indoor terminal based at least on the first cooling load also includes: When the data center cascade refrigeration system is in the second sub-mode, obtaining a rated cooling load corresponding to the plate heat exchanger to obtain a third cooling load; The difference between the first cooling load and the third cooling load is calculated to obtain a fourth cooling load, the operation of the chiller compressor is controlled based on the fourth cooling load, and the opening of the water supply valve is adjusted based on the deviation between the indoor supply air temperature and the set value.

8. A control device for a data center cascade refrigeration system, characterized in that: The data center cascade refrigeration system includes an evaporative cold and hot pipe refrigeration system, a chilled water refrigeration system and an indoor terminal, the indoor terminal is used to cool the indoor environment, the indoor terminal includes a first coil and a second coil, the first coil is connected to the chilled water refrigeration system, the second coil is connected to the evaporative cold and hot pipe refrigeration system, and the device includes: A first acquisition unit is used to acquire an outdoor wet-bulb temperature to obtain a first target temperature, and to acquire an indoor return air temperature to obtain a second target temperature; a first calculation unit, configured to calculate a difference between the first target temperature and the second target temperature to obtain a first target temperature difference; a first control unit, configured to control the data center cascade refrigeration system to enter a first refrigeration mode when the first target temperature is greater than a first preset temperature and the first target temperature difference is less than a first threshold value, wherein the first refrigeration mode is a mode in which only the chilled water refrigeration system is turned on and the indoor terminal cools the indoor environment through the first coil; A second control unit is used to control the data center cascade refrigeration system to enter a second refrigeration mode when the first target temperature is less than or equal to the first preset temperature and greater than the second preset temperature and the first target temperature difference is greater than or equal to the first threshold value, wherein the second refrigeration mode is a mode in which the chilled water refrigeration system and the evaporative cold and hot pipe refrigeration system are turned on at the same time, and the indoor terminal cools down the indoor temperature through the first coil and the second coil; A third control unit is used to control the data center cascade refrigeration system to enter a third refrigeration mode when the first target temperature is less than or equal to the second preset temperature and the first target temperature difference is greater than or equal to a second threshold value. The third refrigeration mode is a mode in which only the evaporative hot and cold pipe refrigeration system is turned on and the indoor terminal cools down the indoor temperature through the second coil, and the second threshold value is greater than the first threshold value.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium includes a stored program, wherein when the program is executed, the device where the computer-readable storage medium is located is controlled to execute the method according to any one of claims 1 to 7.

10. A data center cascade cooling system, characterized in that: include: One or more processors, a memory, and one or more programs, wherein the one or more programs are stored in the memory and are configured to be executed by the one or more processors, and the one or more programs include methods for executing any one of claims 1 to 7.

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