A method of controlling a container data center cooling system

Abstract

The application relates to a control method of a container data center cooling system, which comprises the following steps: S1, detecting internal air supply temperature Ts, internal return air temperature Tr, external wet bulb temperature Tw and external dry bulb temperature Tg in real time; S2, judging the comparison result of Ts and set container internal air supply temperature T1; if Ts >= T1, the refrigeration system is started, and step S3 is entered; if Ts < T1, the refrigeration system is on standby, and the present situation is maintained; S3, if Tw >= Tr-&T, a compressor refrigeration operation mode is started, a temperature difference ratio beta is continuously calculated by (Ts-T1) / alpha T, the compressor is controlled by PID load addition and subtraction according to the value of the temperature difference ratio beta, and step S3.1 is entered; if Tw < Tr-&T, a natural cold refrigeration operation mode is started, a temperature difference ratio beta is continuously calculated by (Ts-T1) / alpha T, and step S3.2 is entered. The method can intelligently switch and combine the compressor refrigeration operation mode, the natural cold refrigeration operation mode and the combined cooling operation mode according to the real-time detected data, can meet the refrigeration demand, and can greatly save energy consumption.

Description

Technical Field

[0001] This invention relates to the field of data center cooling system technology, and specifically to a control method for a containerized data center cooling system. Background Technology

[0002] Containerized data centers are prefabricated, modularly manufactured data center products with advantages such as rapid deployment and centralized delivery. In recent years, the application of containerized data center products has increased significantly, leading to a wide variety of cooling systems to match them. Many existing containerized data centers primarily use mechanical compressor cooling, but this type of data center has a high Power Usage Effectiveness (PUE) and poor economic efficiency in daily operation. To reduce the PUE value of containerized data centers, existing systems have begun to utilize indirect evaporative cooling technology to partially or fully utilize natural cold sources for cooling.

[0003] In the application of indirect evaporative cooling technology for natural cooling in container data centers, the following problems have gradually emerged: the cooling system only determines the switching between mechanical cooling, combined cooling, and all-natural cooling modes based on the outdoor temperature or outdoor wet-bulb temperature. The switching control of the three operating modes is simplistic. For example, when the detected temperature is greater than 28°C, only mechanical cooling is turned on; when the temperature is between 15°C and 28°C, both mechanical cooling and natural cooling are turned on; and when the temperature is below 15°C, only natural cooling is turned on. The mixed-mode cooling control strategy for the unit is crude. For these reasons, the annual PUE of container data centers is relatively high. Summary of the Invention

[0004] This invention, centered on the goal of all-natural cooling, designs a control method for a container data center cooling system. It can intelligently switch and combine compressor cooling operation mode, natural cooling operation mode, and combined cooling operation mode based on real-time detected data, thereby greatly saving energy while meeting cooling requirements.

[0005] The technical solutions of the embodiments of the present invention are as follows:

[0006] A control method for a containerized data center cooling system, the method comprising the following steps:

[0007] S1: Real-time monitoring of the container's internal supply air temperature Ts, internal return air temperature Tr, external wet-bulb temperature Tw, and external dry-bulb temperature Tg.

[0008] S2: Determine the comparison result between Ts and the set internal air supply temperature T1 of the container; if Ts ≥ T1, the refrigeration system is turned on and proceeds to step S3; if Ts < T1, the refrigeration system is in standby mode and the status quo is maintained.

[0009] S3: If Tw ≥ Tr-&T, the compressor refrigeration operation mode is turned on and the temperature difference ratio β is continuously calculated by (Ts - T1) / αT. Based on the value of the temperature difference ratio β, the compressor is controlled to perform PID load increase / decrease, and the process proceeds to step S3.1; if Tw < Tr-&T, the natural cooling operation mode is turned on and the temperature difference ratio β is continuously calculated by (Ts - T1) / αT, and the process proceeds to step S3.2; where &T is the set tolerance value for the return air temperature inside the container, and αT is the set tolerance value for the supply air temperature inside the container.

[0010] S3.1: When Tw < Tr-&T, the natural cooling operation mode is turned on and the combined cooling operation mode is entered; in the compressor cooling operation mode or the combined cooling operation mode, when the compressor is unloaded to the set minimum frequency H1 and the duration exceeds the set duration T1, the compressor is turned off.

[0011] S3.2: When β≥ 0.8, the compressor refrigeration operation mode is turned on and enters the combined cooling operation mode. The compressor performs PID load increase and decrease according to the temperature difference ratio β. When the compressor is unloaded to the set minimum frequency H1 and the duration exceeds the set duration T1, the compressor is turned off.

[0012] Preferably, in the combined cooling operation mode of steps S3.1 and S3.2, Tw ≥

[0013] Tr-&T: Natural cooling mode is off.

[0014] Preferably, in the compressor refrigeration operation mode and combined cooling operation mode in steps 3, S3.1 and S3.2, the condenser condensing pressure Pc is continuously monitored in real time. When Pc ≥ P1, the condenser fan and condenser air humidification device are turned on. When Pc < P1, the condenser fan is turned off. P1 is the set condensing pressure.

[0015] Preferably, in the natural cooling operation mode and combined cooling operation mode in steps 3, S3.1 and S3.2, if Tg ≥ 5℃, the outdoor air humidification device is turned on.

[0016] Preferably, the condenser fan adjusts its speed using a PID control based on the Pc value.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: by real-time detection of the container's internal supply air temperature Ts, internal return air temperature Tr, external wet-bulb temperature Tw, and external dry-bulb temperature Tg, and by comparing the results, the invention can control the opening and closing of the compressor refrigeration operation mode, the natural cooling refrigeration operation mode, and the combined cooling refrigeration operation mode. Furthermore, by performing PID control on the compressor based on the temperature difference ratio β during compressor operation, the invention effectively extends the utilization rate and time of natural cooling, increases the proportion of natural cooling operation mode, achieves the goal of reducing energy consumption, and results in a lower PUE throughout the year. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the container data center and its cooling system in this invention;

[0019] Figure 2 This is a flowchart summarizing the control method of the container data center cooling system in this invention;

[0020] Figure 3 This is a control flowchart of the control method for the container data center cooling system in this invention;

[0021] Containerized IT carrying unit; 14. Hot aisle; 15. Cold aisle; 20. Indirect evaporative precision air conditioning unit; 21. Internal circulation air inlet; 22. Indirect air-to-air sensible heat exchanger; 23. Internal circulation fan; 24. Internal circulation air outlet; 25. External circulation air inlet; 26. External circulation fan; 27. External circulation air outlet; 28. Outdoor air humidifier; 31. Compressor; 32. Evaporator; 331. Condenser; 332. Temperature sensor; 333. Condensed air humidifier; 34. Condenser fan. Detailed Implementation

[0022] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0023] It should be noted that when a component is said to be "fixed to" another component, it can be directly attached to the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0025] The control method of this invention is based on a containerized data center cooling system and describes a method for controlling this cooling system. The containerized data center and cooling system are described below:

[0026] As shown in Figure 1, Figure 1 This is a schematic diagram of a containerized data center structure, which consists of an indirect evaporation precision air conditioning unit 20 (i.e., a cooling system) and a containerized IT support unit 10. The indirect evaporation precision air conditioning unit 20 is connected to the containerized IT support unit 10 through a gas channel, and the indirect evaporation precision air conditioning unit 20 dissipates heat and cools the containerized IT support unit 10. The structure of the indirect evaporation precision air conditioning unit 20 and the containerized IT support unit 10 will be described in detail below.

[0027] The indirect evaporation precision air conditioning unit 20 includes a housing, an outdoor air humidifier 28 placed inside the housing or fixed to the housing, an external circulation air inlet 25, an internal circulation air inlet 21, a partition-type air-to-air sensible heat exchanger 22, an external circulation air outlet 27, an internal circulation air outlet 24, an internal circulation fan 23, an external circulation fan 26, and a controller. In this embodiment, the internal circulation air inlet 21, the partition-type air-to-air sensible heat exchanger 22, the internal circulation fan 23, and the internal circulation air outlet 24 are sequentially connected together to form an internal circulation channel. Figure 1 The direction indicated by the AA arrow in the diagram is the direction of the hot air circulation within the container IT carrying unit 10 in the internal circulation channel; the external circulation air inlet 25, the outdoor air humidifier 28, the partition-type air-to-air sensible heat exchanger 22, the external circulation fan 26, and the external circulation air outlet 27 are connected in sequence to form the external circulation channel. Figure 1 The direction indicated by the BB arrow in the diagram is the direction of the natural cool air circulation within the indirect evaporation precision air conditioning unit 20 in the external circulation channel. In this embodiment, the outdoor air humidification device humidifies and cools the natural air entering from the outside.

[0028] In this way, the hot air inside the container IT support unit 10 and the humidified natural cool air inside the indirect evaporation precision air conditioning unit 20 exchange heat in the indirect air-to-air sensible heat exchanger 22. After the exchange is completed, the hot air cools down, and the natural cool air heats up. The hot air returns to the container IT support unit 10 after cooling down, while the natural cool air is discharged to the outside of the indirect evaporation precision air conditioning unit 20 through the external circulation outlet 27 after heating up. Through the heat exchange between the external natural cool air and the container IT support unit 10, the purpose of cooling the container IT support unit 10 is achieved.

[0029] Typically, the container IT carrying unit 10 includes a cold aisle 15 and a hot aisle 14. The internal circulation air inlet 21 of the indirect evaporation precision air conditioning unit 20 is connected to the hot aisle 14 through a pipe, and the internal circulation air outlet 24 of the indirect evaporation precision air conditioning unit 20 is connected to the cold aisle 15 through a pipe. In this way, the hot air in the hot aisle 14 of the container IT carrying unit 10 enters the internal circulation channel of the indirect evaporation precision air conditioning unit 20 through the internal circulation air inlet 21 and exchanges heat with the natural cold air. After the exchange is completed, it flows back to the cold aisle 15 of the container IT carrying unit 10 through the internal circulation air outlet 24, and so on.

[0030] Of course, the opening and closing of the internal circulation fan 23 and the external circulation fan 26 are both intelligently controlled. In this embodiment, the internal circulation fan 23 and the external circulation fan 26 are electrically connected to the controller, and the controller intelligently controls the opening and closing of the internal circulation fan 23 and the external circulation fan 26.

[0031] In this embodiment, the indirect evaporative precision air conditioning unit 20 also includes a mechanical refrigeration device. Specifically, the mechanical refrigeration device includes a condenser fan 34, a compressor 31, an evaporator 32, and an evaporative condenser. The evaporator 32 is located between the internal circulation air outlet 24 and the indirect air-to-air sensible heat exchanger 22. The hot air that has been cooled by heat exchange in the indirect air-to-air sensible heat exchanger 22 passes through the evaporator 32 for secondary cooling. The cooled hot air becomes cold air and is discharged from the internal circulation air outlet 24 into the cold aisle 15 in the container IT carrying unit 10. In order to reduce the energy consumption of the entire refrigeration system, it is necessary to reduce the heat dissipation pressure of the condenser and accelerate the heat dissipation and cooling speed of the condenser. In this embodiment, spray evaporative cooling is adopted for the condenser. Specifically, the evaporative condenser includes a condenser 331, a condensing air humidifier 333, and a temperature sensor 332. The condenser 331 is connected to the compressor 31 and the evaporator 32 through a capillary tube and an expansion valve to form a refrigeration system. The temperature sensor 332 is installed on the condenser 331 and detects the ambient temperature and humidity of the environment where the condenser 331 is located. The condensing air humidifier 333 is located in front of the condenser 331 and sprays water mist onto the finned pipes of the condenser 331. The water mist evaporates and absorbs heat to cool the refrigerant in the pipes of the condenser 331. The temperature sensor 332, the compressor 31, the condensing air humidifier 333, and the condenser fan 34 are all electrically connected to the controller.

[0032] The above also includes some temperature sensors not specifically described, such as the container's internal supply air temperature sensor, return air temperature sensor, container external wet-bulb temperature difference sensor, and container external dry-bulb temperature sensor. These are all installed at the required detection points and transmit the detected data to the controller. This article will not go into detail about them.

[0033] The control method of the present invention is based on the cooling system of the container data center described above. The container data center described above is also a common structure. The control method of the present invention can be applied to the cooling system of most container data centers. The control method is described in detail below.

[0034] like Figure 2 As shown, Figure 2 This is a flowchart summarizing the control method for a containerized data center cooling system according to the present invention; a control method for a containerized data center cooling system includes the following steps:

[0035] S1: Real-time monitoring of the container's internal supply air temperature Ts, internal return air temperature Tr, external wet-bulb temperature Tw, and external dry-bulb temperature Tg.

[0036] After the container data center cooling system is powered on and started, the supply air temperature sensor, return air temperature sensor, container external wet-bulb temperature difference sensor, and container external wet-bulb temperature difference sensor continuously monitor the supply air temperature Ts, return air temperature Tr, wet-bulb temperature Tw, and dry-bulb temperature Tg in real time, and convert the detected values ​​into electrical signals and transmit them to the controller. The controller processes the detected electrical signals.

[0037] S2: Determine the comparison result between Ts and the set internal air supply temperature T1 of the container; if Ts ≥ T1, the refrigeration system is turned on and proceeds to step S3; if Ts < T1, the refrigeration system is in standby mode and the status quo is maintained.

[0038] After the cooling system is started, the supply air temperature T1 is set according to the needs of the container data center. The real-time detected supply air temperature Ts is compared with the set supply air temperature T1. If Ts ≥ T1, the actual supply air temperature is greater than the temperature required by the container data center, and the cooling system needs to be turned on to start cooling. If Ts < T1, the actual supply air temperature is less than the temperature required by the container data center, and the requirements of the container data center are met, the cooling system is temporarily in standby mode. The cooling system will be restarted when the heat dissipation of the container data center server triggers Ts ≥ T1.

[0039] S3: If Tw ≥ Tr-&T, the compressor refrigeration operation mode is turned on and the temperature difference ratio β is continuously calculated by (Ts - T1) / αT. Based on the value of the temperature difference ratio β, the compressor is controlled to perform PID load increase / decrease, and the process proceeds to step S3.1; if Tw < Tr-&T, the natural cooling operation mode is turned on and the temperature difference ratio β is continuously calculated by (Ts - T1) / αT, and the process proceeds to step S3.2; where &T is the set tolerance value for the return air temperature inside the container, and αT is the set tolerance value for the supply air temperature inside the container.

[0040] After the refrigeration system is started, three cooling operation modes are available: compressor refrigeration mode, natural cooling mode, and combined cooling mode. When the external dry-bulb temperature is lower than the internal return air temperature, cooling can be achieved using the temperature difference. However, dry-bulb temperatures are typically higher in most seasons, resulting in limited usage time and low efficiency of natural cooling. Therefore, indirect evaporative cooling is proposed, which involves humidifying the external air to bring it close to the ambient wet-bulb temperature. Thus, natural cooling can be utilized as long as the external air temperature is lower than the return air temperature, significantly extending the usage period. In this invention, the external ambient wet-bulb temperature is compared with the real-time detected return air temperature. In this invention, δ represents the set tolerance value for the return air temperature inside the container, determined based on the cooling efficiency of the heat exchange core. Higher core efficiency results in higher δ... fsetThe smaller the value, the lower the heat exchange core efficiency is within this setpoint compared to the compressor mode efficiency. The start of the cooling operation mode is selected by comparing Tw and Tr-&T. If Tw ≥ Tr-&T, the compressor cooling mode is started. During compressor operation, the controller continuously calculates (Ts - T1) / αT based on the real-time detection value to obtain the temperature difference ratio β. Based on the value of the temperature difference ratio β, the controller controls the compressor to perform PID load increase / decrease, and then proceeds to the next step S3.1 for another judgment. If Tw < Tr-&T, the natural cooling operation mode is turned on. In the natural cooling operation mode, the controller continuously calculates (Ts - T1) / αT based on the real-time detection value to obtain the temperature difference ratio β, and then proceeds to the next step S3.2 for another judgment. In both compressor refrigeration and combined cooling operation modes, to reduce energy consumption, the condenser condensing pressure needs to be maintained at a very low level. This necessitates a control method to reduce the condenser condensing pressure. In this embodiment, preferably, step S3 further includes the following control method: continuously monitoring the condenser condensing pressure Pc in real time. When Pc ≥ P1, the condenser fan and condenser air humidification device are activated. The condenser air humidification device humidifies and cools the outside air, while the condenser fan draws in the cooled air to cool the condenser. More preferably, the condenser fan speed is PID-regulated based on the Pc value to further reduce the condenser fan's power consumption during operation. When Pc < P1, the condensing pressure is at a relatively low value, and the condenser fan is turned off to reduce power consumption. P1 is the set minimum condensing pressure. In both the natural cooling and combined cooling operation modes, the outdoor air humidifier can only be activated when the external air environment is suitable for humidification and cooling. In this embodiment, step S3 further includes the following control method: if Tg ≥ 5℃, the outdoor air humidifier is activated to prevent frost and ice formation caused by humidification at even lower temperatures. The condenser fan speed is adjusted using PID control based on the Pc value.

[0041] S3.1: When Tw < Tr-&T, the natural cooling operation mode is turned on and the combined cooling operation mode is entered; in the compressor cooling operation mode or the combined cooling operation mode, when the compressor is unloaded to the set minimum frequency H1 and the duration exceeds the set duration T1, the compressor is turned off.

[0042] In the compressor cooling operation mode, when the compressor is unloaded to the set minimum frequency H1 and continues to run at the minimum frequency H1 for a set duration S1, the compressor shuts down. During the compressor cooling operation mode, the controller simultaneously detects Tw and Tr. When it detects that Tw < Tr-&T at a certain moment, the natural cooling operation mode is activated. At this time, the compressor and natural cooling are activated together to form a combined cooling operation mode. When the compressor is unloaded to the set minimum frequency H1 and continues to run at the minimum frequency H1 for a set duration S1, the compressor shuts down. To ensure that changes in external temperature and external air environment do not negatively impact the refrigeration system, preferably, in the combined cooling operation mode in this step, when the real-time detection value satisfies Tw ≥ Tr-&T, the natural cooling operation mode is shut down, and the compressor cooling operation mode operates independently. In the compressor refrigeration operation mode and combined cooling operation mode, in order to reduce energy consumption, the condenser condensing pressure needs to be kept at a very low level. This requires a control method to reduce the condenser condensing pressure. In this embodiment, preferably, step S3 also includes the following control method: continuously monitor the condenser condensing pressure Pc in real time. When Pc ≥ P1, turn on the condenser fan and the condenser air humidification device. The condenser air humidification device humidifies and cools the outside air, and the condenser fan draws in the cooled air to cool the condenser. When Pc < P1, the condensing pressure is at a low pressure value, and the condenser fan is turned off to reduce power consumption. P1 is the set minimum condensing pressure. In the natural cooling refrigeration operation mode and combined cooling operation mode, the outdoor air humidification device can only be turned on when the outside air environment is suitable for humidification and cooling. In this embodiment, step S3 also includes the following control method: if Tg ≥ 5℃, the outdoor air humidification device is turned on to prevent frost and ice formation caused by humidification at lower temperatures.

[0043] S3.2: When β≥ 0.8, the compressor refrigeration operation mode is turned on and enters the combined cooling operation mode. The compressor performs PID load increase and decrease according to the temperature difference ratio β. When the compressor is unloaded to the set minimum frequency H1 and the duration exceeds the set duration T1, the compressor is turned off.

[0044] In the natural cooling mode, the controller continuously calculates the temperature difference ratio β (Ts - T1) / αT based on the real-time detection value. When β ≥ 0.8, the compressor cooling mode is activated, and the system enters the combined cooling mode. The compressor performs PID load adjustment based on the temperature difference ratio β. When the compressor is unloaded to the set minimum frequency H1 and continues to run at the minimum frequency H1 for more than the set duration S1, the compressor shuts down. Simultaneously, to ensure that changes in external temperature and air environment do not negatively impact the refrigeration system, preferably, in the combined cooling mode of this step, when the real-time detection value satisfies Tw ≥ Tr-&T, the natural cooling mode is deactivated, and the compressor cooling mode operates independently. In the compressor refrigeration operation mode and combined cooling operation mode, in order to reduce energy consumption, the condenser condensing pressure needs to be kept at a very low level. This requires a control method to reduce the condenser condensing pressure. In this embodiment, preferably, step S3 also includes the following control method: continuously monitor the condenser condensing pressure Pc in real time. When Pc ≥ P1, turn on the condenser fan and the condenser air humidification device. The condenser air humidification device humidifies and cools the outside air, and the condenser fan draws in the cooled air to cool the condenser. When Pc < P1, the condensing pressure is at a low pressure value, and the condenser fan is turned off to reduce power consumption. P1 is the set minimum condensing pressure. In the natural cooling refrigeration operation mode and combined cooling operation mode, the outdoor air humidification device can only be turned on when the outside air environment is suitable for humidification and cooling. In this embodiment, step S3 also includes the following control method: if Tg ≥ 5℃, the outdoor air humidification device is turned on to prevent frost and ice formation caused by humidification at lower temperatures.

[0045] like Figure 3 As shown, Figure 3 This is a control flowchart of the control method for the container data center cooling system in this invention; examples from the operation process are listed below to illustrate the control method flow.

[0046] The temperature T1 is set according to the power density of the container server. T1 is typically set between 20 and 33°C; in this embodiment, T1 is set to 26°C. The minimum condensing pressure P1 of the condenser is set; P1 is typically set between 20 and 22 bar; in this embodiment, P1 is set to 22 bar. The minimum operating frequency H1 of the compressor is set; in this embodiment, H1 is set to 25 Hz. The duration S1 for the compressor to operate at the minimum frequency is set; in this embodiment, S1 is set to 5 minutes. The air supply temperature inside the container data center is set. In this embodiment, the tolerance value αT is set to 3°C. It serves as a reference value for calculating the difference between the measured supply air temperature and the set supply air temperature. The compressor can perform PID load adjustment based on the calculated temperature difference ratio. The return air temperature tolerance value &T inside the container data center is set. &T is determined based on the cooling efficiency of the heat exchange core. The higher the core efficiency, the smaller &T is. Within this setting, the energy efficiency of the heat exchange core is lower than the energy efficiency of the compressor mode. In this embodiment, &T is usually set to 1°C. It serves as the natural cooling start temperature difference and is used together with the measured return air temperature for calculation.

[0047] Taking a common environment as an example below, the control method of the cooling system of the present invention will be specifically described. In this embodiment, the external environment has a dry bulb temperature of 30°C, a relative humidity of 73%, and a wet bulb temperature of 26°C. After the system is started, the container data center operates, and the real-time supply air temperature and return air temperature in the container data center are detected. The dry bulb temperature and wet bulb temperature of the external environment are detected in real time, and the detected values are fed back to the controller. The controller compares the real-time detected supply air temperature Ts with the standard temperature T1 set for the data center. When Ts < 26°C, the temperature in the container data center is lower than the standard temperature, and the servers in the container data center operate safely, and the refrigeration system is on standby; when the servers gradually operate and the heat dissipation gradually increases, the temperature in the container data center also gradually rises. When it rises to 26°C, the refrigeration system is started. After the controller and other services operate for a period of time, it is further determined whether to first start the compression refrigeration operation mode or the free cooling operation mode. In this embodiment, by comparing the real-time measured ambient wet bulb temperature Tw with the real-time detected return air temperature Tr and the return air temperature tolerance &T, when the wet bulb temperature Tw is 26°C, the return air temperature Tr is 30°C, and Tw < Tr - &T, the refrigeration system first enters the free cooling operation mode. Only when the wet bulb temperature is less than the return air temperature can there be a temperature difference for heat exchange. When the server load is not very large, at this time the return air temperature is relatively low, for example, when it is 27°C, the wet bulb temperature is greater than or equal to the return air temperature opening tolerance, and at this time the free cooling refrigeration operation mode cannot play a role in heat exchange and cooling, so it is necessary to first enter the compression refrigeration. Or the required temperature standard in the container data is increased, for example, increased to 22°C. Since the external environment wet bulb temperature is 26°C, it cannot play a role in cooling the data center. At this time, it directly enters the compression refrigeration operation mode and directly outputs a lower temperature for cooling; first enter the free cooling refrigeration operation mode, and the controller calculates (Ts - T1) / αT in real time to obtain the temperature difference ratio β. For example, the real-time detected supply air temperature is 28.5°C, and at this time β = 0.83 is calculated. And when β ≥ 0.8 indicates that the temperature is too high and rapid cooling is needed. At this time, the compressor cooling mode is activated, entering a combined cooling mode. In this mode, the compressor uses PID control based on the temperature difference ratio β. When β increases, the compressor loads; when β decreases, the compressor unloads. As β gradually decreases, the compressor gradually unloads. When the compressor unloads to the minimum set operating frequency H1 and runs at 25Hz for a set duration S1 for 5 minutes, the temperature has gradually stabilized within a low range. At this point, the compressor can be shut down, and natural cooling mode can be used to maintain the current internal temperature. While calculating the β value in real time, the controller also compares the real-time return air temperature tolerance with the real-time detected wet-bulb temperature. When the return air temperature tolerance is 26℃, and the external wet-bulb temperature is also 26℃, natural cooling will not cool the data center. Therefore, the natural cooling mode needs to be shut down to fully utilize the compressor's cooling efficiency. After entering the compressor cooling mode, the controller first calculates (Ts...) in real time... The temperature difference ratio β is calculated as -T1) / αT. The compressor uses PID control to adjust its load based on the β value. When β increases, the compressor loads; when β decreases, the compressor unloads. Simultaneously, the controller compares the real-time return air temperature tolerance with the real-time detected wet-bulb temperature. When the return air temperature tolerance is 28℃, and the external ambient wet-bulb temperature is 26℃, natural cooling can handle a portion of the cooling. At this point, the natural cooling mode is activated to fully depressurize the compressor, entering a combined cooling mode. As the β value gradually decreases, the compressor gradually unloads. When the compressor unloads to the minimum set operating frequency H1 and runs continuously at 25Hz for the set S1 for 5 minutes, it indicates that the temperature has gradually stabilized within a low range. At this point, the compressor can be shut down, and only the natural cooling mode needs to be used to maintain the current internal ambient temperature.

[0048] In this invention, the natural cooling mode mainly utilizes the wet-bulb temperature of dry air for cooling and heat exchange. Therefore, the natural cooling mode can only be activated when the ambient wet-bulb temperature is greater than 0°C. In this invention, the outdoor air humidifier can only be activated to humidify and cool the outdoor air when the dry-bulb temperature is greater than 5°C.

[0049] In both compressor refrigeration and combined cooling operation modes, to reduce compressor power consumption, it is necessary to reduce the pressure at the condenser end. In this invention, the controller monitors the condenser pressure in real time and compares the detected value Pc with the set condenser pressure value P1. For example, when the detected condenser pressure is 25 bar, it is greater than the set P1 value of 22 bar. At this time, the refrigeration system turns on the condenser fan and condenser air humidifier to quickly cool the condenser and reduce compressor power consumption. When the condenser pressure is less than the set condenser pressure, the condenser fan and condenser air humidifier are turned off to reduce operating power consumption. For example, if the real-time detected value is 20 bar, which is less than the set P1 value of 22 bar, the condenser fan and condenser air humidifier are turned off.

[0050] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0051] The above embodiments merely illustrate preferred implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention should be determined by the appended claims.

Claims

1. A control method for a cooling system of a container data center, characterized in that: The method includes the following steps: S1: Real-time detect the internal supply air temperature Ts, the internal return air temperature Tr, the external wet bulb temperature Tw, and the external dry bulb temperature Tg of the container; S2: Determine the comparison result between Ts and the set internal supply air temperature T1 of the container; if Ts ≥ T1, the refrigeration system is turned on and step S3 is entered; if Ts < T1, the refrigeration system stands by and maintains the current state; S3: If Tw ≥ Tr - &T, the compressor refrigeration operation mode is turned on and continuously calculate (Ts - T1) / αT to obtain the temperature difference ratio β, and control the compressor to perform PID loading and unloading according to the value of the temperature difference ratio β, and enter step S3.1; if Tw < Tr - &T, the natural cooling refrigeration operation mode is turned on and continuously calculate (Ts - T1) / αT to obtain the temperature difference ratio β, and enter step S3.2; the &T is the set internal return air temperature tolerance value of the container, and the αT is the set internal supply air temperature tolerance value of the container; S3.1: When Tw < Tr - &T, the natural cooling refrigeration operation mode is turned on and enters the combined cooling operation mode; in the compressor refrigeration operation mode or the combined cooling operation mode, when the compressor unloads to the set minimum frequency H1 and the duration exceeds the set duration S1, the compressor is turned off; S3.2: When β≥ 0.8, the compressor refrigeration operation mode is turned on and enters the combined cooling operation mode, and the compressor performs PID loading and unloading according to the value of the temperature difference ratio β. When the compressor unloads to the set minimum frequency H1 and the duration exceeds the set duration S1, the compressor is turned off.

2. The control method according to claim 1, characterized in that: In the combined cooling operation mode in step S3.1 and step S3.2, when Tw ≥ Tr - &T, The natural cooling refrigeration operation mode is turned off.

3. The control method according to claim 1, characterized in that: In the compressor refrigeration operation mode and the combined cooling operation mode in step 3, step S3.1, and step S3.2, the condenser condensation pressure Pc is detected in real time. When Pc≥ P1, the condensation fan and the condensation air humidification device are turned on. When Pc < P1, the condensation fan is turned off. The P1 is the set minimum condensation pressure.

4. The control method according to claim 1, characterized in that: In the natural cooling refrigeration operation mode and the combined cooling operation mode in step 3, step S3.1, and step S3.2, if Tg ≥ 5°C, the outdoor air humidification device is turned on.

5. The control method according to claim 3, characterized in that: The condensation fan adjusts the rotation speed according to the Pc value by PID.

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