A method for zoned control of inter-row air conditioning fans

Abstract

This invention relates to a method for zoned control of inter-row air conditioning fans. The inter-row air conditioner can monitor the cold aisle return air temperatures T1, T2, and T3, and the hot aisle outlet air temperatures T4, T5, and T6 at different cabinet heights. Based on the controller's set cold aisle temperature protection value T7, return air temperature setpoint T8, and unbalanced temperature difference setpoint T9 as judgment targets, the method controls the speed of the inter-row air conditioning fans according to different modes, including the following steps: S1 After the inter-row air conditioner is turned on, it runs at its minimum speed for a certain period; S2 Determine the relationship between Tmin (T4, T5, T6) and T7; S3 Determine the relationship between Tmax (T1, T2, T3) and T8; S4 The inter-row air conditioner cools, and the relationship between the return air temperature imbalance value ΔT = Tmax (T1, T2, T3) - Tmin (T1, T2, T3) and T9 is determined. This invention can reduce power consumption, improve the control accuracy of air temperature in the cold aisle, prevent a large influx of high-temperature air from the hot aisle into the cold aisle, and ensure temperature uniformity within the cold aisle.

Description

Technical Field

[0001] This invention relates to a method for zoned control of inter-row air conditioning fans, belonging to the field of inter-row air conditioning technology. Background Technology

[0002] Since the beginning of 2020, the construction of communication infrastructure such as data centers has shown a rapid development trend. Among them, modular data centers, as an energy-efficient, rapidly deployable, and deeply prefabricated solution, have received much attention and favor from the industry. In modular data centers, in-row air conditioners are installed side by side with server racks, and the air conditioner return or supply air areas are isolated and enclosed by channels to solve the problems of mixing and short-circuiting of hot and cold air in conventional computer room air conditioners. The heat flux density of a single rack can be increased from the traditional 3kW / rack to 10kW / rack. Such a large-scale heat load requires reasonable control of in-row air conditioners to achieve the control goal of safe and efficient cooling of equipment in modular data centers. Existing in-row air conditioners are controlled either based on return air temperature or supply air temperature. Generally, the return air temperature is used to control the cooling capacity output of the air conditioner, i.e., the fan speed; the supply air temperature controls the air conditioner manufacturing end, i.e., the compressor frequency or the opening of the electric water valve. Because the heat load inside the server rack is high and the vertical arrangement is not necessarily uniform, if the traditional fan control method is used, it is easy to form local temperature hotspots, which can cause server equipment to fail. Therefore, it is necessary to improve the existing fan speed control method of in-row air conditioners. Summary of the Invention

[0003] To address the aforementioned technical problems, this invention provides a method for zoned control of inter-row air conditioning fans. This method controls the fan speed based on multiple objectives, including the unevenness of return air temperature and the temperature protection value of the cold aisle. The specific technical solution is as follows:

[0004] A method for zoned control of inter-row air conditioning fans includes a cold aisle A, an inter-row air conditioner B, and a hot aisle C. The EC fan of the inter-row air conditioner B is set with a minimum speed and a maximum speed. Three return air temperature sensors are uniformly arranged along the height direction within the cold aisle A of the inter-row air conditioner B, measuring return air temperatures T1, T2, and T3, respectively. These sensors monitor the return air temperature at different heights within the refrigeration aisle and calculate the maximum value Tmax(T1, T2, T3) and the minimum value Tmin(T1, T2, T3) of the return air temperatures T1, T2, and T3. The difference between the maximum and minimum values ​​is ΔT = Tmax(T1, T2, T3) - Tmin(T1, T2, T3). The inter-row air conditioner has three supply air temperature sensors evenly installed along the height direction within the hot aisle C. These sensors measure the supply air temperatures as T4, T5, and T6, respectively, to monitor the supply air temperature at different heights within the hot aisle and to calculate the minimum value Tmin(T4, T5, T6) of the supply air temperatures T4, T5, and T6. The inter-row air conditioner B is set with a cold aisle temperature protection value T7, a return air temperature setpoint T8, and an unbalanced temperature difference setpoint T9.

[0005] The control method includes the following steps:

[0006] Step S1: After the inter-row air conditioner B is turned on, its EC fan first runs at the minimum speed and maintains a certain delay time.

[0007] Step S2: After the delay period ends, determine the relationship between the minimum supply air temperature Tmin (T4, T5, T6) and the cold aisle temperature protection value T7:

[0008] If Tmin(T4, T5, T6) > T7, the inter-row air conditioning EC fan will continue to operate at minimum speed;

[0009] If Tmin(T4, T5, T6) < T7, then continue to step S3.

[0010] Step S3: Determine the relationship between the maximum return air temperature Tmax (T1, T2, T3) and the return air temperature setpoint T8:

[0011] If Tmax(T1, T2, T3) < T8, then the EC fan of the inter-row air conditioner continues to operate at the minimum speed;

[0012] If Tmax(T1, T2, T3) > T8, then continue to step S4.

[0013] The logical judgment in step S3 is to determine whether the inter-row air conditioner needs to cool. If the return air temperature is lower than the return air temperature setting value, the inter-row air conditioner does not need to run in cooling mode. In order to reduce the power consumption of the air conditioner, the EC fan can run at the minimum speed at this time.

[0014] Step S4: The inter-column air conditioner is turned on in cooling mode. The relationship between the return air temperature imbalance value ΔT = Tmax(T1, T2, T3) - Tmin(T1, T2, T3) and the imbalance temperature difference set value T9 is determined:

[0015] If △T1>T9, the EC fan of the inter-row air conditioner will operate in zone temperature control mode;

[0016] If △T1 < T9, the EC fan of the inter-row air conditioner will operate in average temperature control mode.

[0017] When ΔT1 > T9, the air temperature within the hot aisle is uneven, resulting in localized hot spots. In this case, the air conditioning system should prioritize eliminating these hot spots. Fans in areas with hot spots should operate at relatively high speeds, while fans in areas without hot spots should operate at relatively low speeds.

[0018] When ΔT1 < T9, the air temperature within the hot aisle can be considered relatively uniform, with no localized hot spots. Therefore, the average value AVE(T1, T2, T3) of the hot aisle temperatures T1, T2, and T3 can be taken. The fan speed is then controlled based on the relationship between the average temperature and the return air temperature setpoint T9. In this case, the inter-row air conditioning fans operate at the same uniform speed, maximizing the reduction of fan operating power consumption. It should be noted that the characteristics of EC fans determine that, when outputting the same total air volume, a fan operating at a uniform low speed is more reliable and energy-efficient than a fan operating at varying speeds.

[0019] Furthermore, the delay time in step S1 is in the range of 30s-90s, firstly because the air conditioner's cooling output needs a certain preparation delay during the start-up and operation phase; and secondly because the sensor readings also need a certain stabilization time.

[0020] Furthermore, in step S2, the cold aisle temperature protection value T7 is set in the range of 30-45℃. The main purpose of setting the cold aisle temperature protection value T7 is to prevent the return air with a higher temperature in the hot aisle from being directly sent into the cold aisle by the in-row air conditioner fan when the in-row air conditioner is not cooling, that is, to prevent the air in the cold aisle from generating high temperature and affecting the server equipment.

[0021] Furthermore, in step S3, the return air temperature setpoint T8 is set within the range of 28-40℃. Setting the return air temperature setpoint T8 is mainly the basis for the controller to calculate the fan speed percentage. Generally, when the return air temperature is lower than the setpoint T8, the fan operates at its minimum speed.

[0022] Furthermore, in step S4, the unbalanced temperature difference setting value T9 is set in the range of 3-10℃. The purpose of setting the unbalanced temperature difference setting value T9 is to prevent the generation of local hot spots when the vertical load of the server rack is uneven. If the inter-row air conditioner still outputs cooling capacity uniformly, it will disrupt the uniform airflow organization of the cold aisle. This phenomenon is particularly important in inter-row air conditioners, especially heat pipe inter-row air conditioners.

[0023] Furthermore, the speed control method in the average temperature control mode of step S4 is as follows:

[0024] If the average return air temperature AVE(T1, T2, T3) ≤ (temperature setpoint T9 + quiet zone temperature), then the inter-row air conditioning EC fan will operate at the minimum speed.

[0025] If the average return air temperature AVE(T1, T2, T3) > (temperature setpoint T9 + quiet zone temperature + temperature bandwidth), then the inter-row air conditioning EC fan will operate at its maximum speed.

[0026] If (temperature setpoint T9 + quiet zone temperature) ≤ average return air temperature AVE (T1, T2, T3) ≤ (temperature setpoint T9 + quiet zone temperature + temperature bandwidth), then the EC fan of the inter-row air conditioner will adjust its speed proportionally.

[0027] Furthermore, the speed control method for the temperature control mode in step S4 is as follows:

[0028] If the single-point return air temperature value T1 / T2 / T3 ≤ (temperature setpoint T9 + quiet zone temperature value), then the inter-row air conditioning EC fan will operate at the minimum speed.

[0029] If the single-point return air temperature T1 / T2 / T3 > (temperature setpoint T9 + quiet zone temperature + temperature bandwidth), then the inter-row air conditioning EC fan will operate at its maximum speed.

[0030] If (temperature setpoint T9 + quiet zone temperature) ≤ T1 / T2 / T3 ≤ (temperature setpoint T9 + quiet zone temperature + temperature bandwidth), then the EC fan of the inter-row air conditioner will adjust its speed proportionally.

[0031] It should be noted that the fan control method described in this patent uses return air temperature as the basis for judgment. In actual operation, the fan speed cannot be controlled based on the supply air temperature, because the airflow path on the supply side is too short. Even a slight change in the fan speed will cause a large change in the supply air temperature, which will cause oscillations in the fan speed control, making the PID control unable to stabilize.

[0032] The beneficial effects of this invention are:

[0033] Unlike traditional single-objective control methods that only use the return air temperature of the air conditioner, this invention controls the fan speed based on multiple objectives such as the unevenness of the return air temperature and the temperature protection value of the cold aisle, thereby achieving:

[0034] 1. Reduce power consumption: Maximize the operation of the fans in hot standby mode, thereby enabling the fans to operate at the lowest possible power consumption, reducing the power consumption of the fans and improving the greenness of the data center.

[0035] 2. More precise temperature control: Improves the control precision of air temperature in the cold aisle, preventing large amounts of hot air from rushing into the cold aisle and providing a good working environment for the server.

[0036] 3. Eliminate temperature hotspots along the height of the cabinets in the micro-module data center. When the load distribution in different areas of the cabinet is uneven, the fans of the in-row air conditioners operate in a fan zone control mode to eliminate high-temperature hotspots in the area, thereby ensuring the temperature uniformity in the cold aisle and improving the operational reliability of the server main equipment. Attached Figure Description

[0037] Figure 1 This is the control flowchart of the present invention;

[0038] Figure 2 This is a schematic diagram of the inter-row air conditioning arrangement of the present invention, wherein: A is a schematic cold aisle, B is an inter-row air conditioning unit, and C is a schematic hot aisle;

[0039] Figure 3 This is the average temperature control mode of the present invention;

[0040] Figure 4 This is the regional temperature control mode of the present invention;

[0041] Wherein: T1, T2, and T3 are the return air temperatures measured by three return air temperature sensors; Tmax is the maximum value of return air temperatures T1, T2, and T3; ΔT is the difference between the maximum and minimum values ​​of return air temperatures T1, T2, and T3; AVE(T1, T2, T3) is the average value of return air temperatures T1, T2, and T3; T4, T5, and T6 are the supply air temperatures measured by three supply air temperature sensors; T7 is the cold aisle temperature protection value; T8 is the return air temperature setpoint; and T9 is the unbalanced temperature difference setpoint. Detailed Implementation

[0042] The invention will now be described in further detail with reference to the accompanying drawings.

[0043] like Figure 2The schematic diagram of the in-row air conditioning layout is shown, including cold aisle A, in-row air conditioning unit B, and hot aisle C. The EC fan of in-row air conditioning unit B is set with minimum and maximum speeds. Three return air temperature sensors are evenly distributed along the height of cold aisle A within in-row air conditioning unit B to monitor the return air temperature at different heights within the refrigeration aisle, and to calculate the maximum value Tmax(T1, T2, T3) and the minimum value Tmin(T1, T2, T3) of return air temperatures T1, T2, and T3. The difference between the maximum and minimum values ​​is ΔT = Tmax(T1, T2, T3) - Tmin(T1, T2, T3). Three supply air temperature sensors are evenly distributed along the height of hot aisle C within in-row air conditioning unit C to monitor the supply air temperature at different heights within the hot aisle, and to calculate the minimum value Tmin(T4, T5, T6) of supply air temperatures T4, T5, and T6. The inter-row air conditioner B is set with a cold aisle temperature protection value T7, a return air temperature setting value T8, and an unbalanced temperature difference setting value T9.

[0044] like Figure 1 As shown, the control method includes the following steps:

[0045] Step S1: After the inter-row air conditioner B is turned on, its EC fan will run at the minimum speed for a delay of 60 seconds.

[0046] Step S2: After the delay time ends, determine the relationship between the minimum supply air temperature Tmin (T4, T5, T6) and the cold aisle temperature protection value T7:

[0047] If Tmin(T4, T5, T6) > T7, the inter-row air conditioning EC fan will continue to operate at minimum speed;

[0048] If Tmin(T4, T5, T6) < T7, then continue to step S3.

[0049] The cold aisle temperature protection value T7 is set at 35℃. The main purpose of setting the cold aisle temperature protection value T7 is to prevent the return air with a higher temperature in the hot aisle from being directly sent into the cold aisle by the in-row air conditioning fan when the in-row air conditioning is not cooling. In other words, it prevents the air in the cold aisle from generating high temperature and affecting the server equipment.

[0050] Step S3: Determine the relationship between the maximum return air temperature Tmax (T1, T2, T3) and the return air temperature setpoint T8:

[0051] If Tmax(T1, T2, T3) < T8, then the EC fan of the inter-row air conditioner continues to operate at the minimum speed;

[0052] If Tmax(T1, T2, T3) > T8, then continue to step S4.

[0053] The logical judgment in step S3 is to determine whether the inter-row air conditioner needs to cool. If the return air temperature is lower than the return air temperature setting value, the inter-row air conditioner does not need to run in cooling mode. In order to reduce the power consumption of the air conditioner, the EC fan can run at the minimum speed at this time.

[0054] The return air temperature setpoint T8 is set to 30℃. The return air temperature setpoint T8 is mainly used as the basis for the controller to calculate the percentage of fan speed. Generally, when the return air temperature is lower than the setpoint T8, the fan runs at the minimum speed.

[0055] Step S4: The inter-column air conditioner is turned on in cooling mode. Determine the relationship between the return air temperature imbalance value △T=Tmax(T1, T2, T3)-Tmin(T1, T2, T3) and the imbalance temperature difference setpoint T9:

[0056] If △T1>T9, the EC fan of the inter-row air conditioner will operate in zone temperature control mode;

[0057] If △T1 < T9, the EC fan of the inter-row air conditioner will operate in average temperature control mode.

[0058] The unbalanced temperature difference setting value T9 is set to 7℃. The purpose of setting the unbalanced temperature difference setting value T9 is to prevent the generation of local hot spots when the vertical load of the server rack is uneven. If the in-row air conditioner still outputs cooling capacity evenly, it will disrupt the uniform airflow organization of the cold aisle. This phenomenon is particularly important in in-row air conditioners, especially heat pipe in-row air conditioners.

[0059] When ΔT1 > T9, the air temperature within the hot aisle is uneven, resulting in localized hot spots. In this case, the air conditioning system should prioritize eliminating these hot spots. Fans in areas with hot spots should operate at relatively high speeds, while fans in areas without hot spots should operate at relatively low speeds.

[0060] like Figure 4 As shown, the speed control method in the temperature control mode of step S4 is as follows:

[0061] If the single-point return air temperature value T1 / T2 / T3 ≤ (temperature setpoint T9 + quiet zone temperature value), then the inter-row air conditioning EC fan will operate at the minimum speed.

[0062] If the single-point return air temperature T1 / T2 / T3 > (temperature setpoint T9 + quiet zone temperature + temperature bandwidth), then the inter-row air conditioning EC fan will operate at its maximum speed.

[0063] If (temperature setpoint T9 + quiet zone temperature) ≤ T1 / T2 / T3 ≤ (temperature setpoint T9 + quiet zone temperature + temperature bandwidth), then the EC fan of the inter-row air conditioner will adjust its speed proportionally.

[0064] When ΔT1 < T9, the air temperature within the hot aisle can be considered relatively uniform, with no localized hot spots. Therefore, the average value AVE(T1, T2, T3) of the hot aisle temperatures T1, T2, and T3 can be taken. The fan speed is then controlled based on the relationship between the average temperature and the return air temperature setpoint T9. In this case, the inter-row air conditioning fans operate at the same uniform speed, maximizing the reduction of fan operating power consumption. It should be noted that the characteristics of EC fans determine that, when outputting the same total air volume, a fan operating at a uniform low speed is more reliable and energy-efficient than a fan operating at varying speeds.

[0065] like Figure 3 As shown, the speed control method in step S4, the average temperature control mode, is as follows:

[0066] If the average return air temperature AVE(T1, T2, T3) ≤ (temperature setpoint T9 + quiet zone temperature), then the inter-row air conditioning EC fan will operate at the minimum speed.

[0067] If the average return air temperature AVE(T1, T2, T3) > (temperature setpoint T9 + quiet zone temperature + temperature bandwidth), then the inter-row air conditioning EC fan will operate at its maximum speed.

[0068] If (temperature setpoint T9 + quiet zone temperature) ≤ average return air temperature AVE (T1, T2, T3) ≤ (temperature setpoint T9 + quiet zone temperature + temperature bandwidth), then the EC fan of the inter-row air conditioner will adjust its speed proportionally.

[0069] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. An air conditioning fan zoning control method for column, characterized in that: The control method comprises the following steps: Step S1: after the inter-row air conditioner B is started, the EC fan runs at the minimum speed and maintains a certain delay time; Step S2: after the delay time ends, the size relationship between the minimum value Tmin(T4, T5, T6) of the supply air temperature and the cold aisle temperature protection value T7 is determined: If Tmin(T4, T5, T6) > T7, the inter-row air conditioner EC fan continues to run at the minimum speed; If Tmin(T4, T5, T6) < T7, continue to step S3; Step S3: the size relationship between the maximum value Tmax(T1, T2, T3) of the return air temperature and the return air temperature set value T8 is determined: If Tmax(T1, T2, T3) < T8, the inter-row air conditioner EC fan continues to run at the minimum speed; If Tmax(T1, T2, T3) > T8, continue to step S4; Step S4: the inter-row air conditioner is started in the refrigeration state, and the size relationship between the return air temperature imbalance value AT = Tmax(T1, T2, T3) - Tmin(T1, T2, T3) and the imbalance temperature difference set value T9 is determined: If AT1 > T9, the inter-row air conditioner EC fan runs in the regional temperature control mode; If AT1 < T9, the inter-row air conditioner EC fan runs in the average temperature control mode; The speed control method of the step S4 regional temperature control mode is as follows: If the single-point value T1 / T2 / T3 of the return air temperature is ≤ (the temperature set value T9 + the dead zone temperature value), the inter-row air conditioner EC fan runs at the minimum speed; If the single-point value T1 / T2 / T3 of the return air temperature is > (the temperature set value T9 + the dead zone temperature value + the temperature bandwidth value), the inter-row air conditioner EC fan runs at the maximum speed; If (the temperature set value T9 + the dead zone temperature) ≤ T1 / T2 / T3 ≤ (the temperature set value T9 + the dead zone temperature value + the temperature bandwidth value), the inter-row air conditioner EC fan runs at the proportionally adjusted fan speed; The speed control method of the step S4 average temperature control mode is as follows: If the average value AVE(T1, T2, T3) of the return air temperature is ≤ (the temperature set value T9 + the dead zone temperature value), the inter-row air conditioner EC fan runs at the minimum speed; If the average value AVE(T1, T2, T3) of the return air temperature is > (the temperature set value T9 + the dead zone temperature value + the temperature bandwidth value), the inter-row air conditioner EC fan runs at the maximum speed; If (temperature setting value T9 + static zone temperature value) <= return air temperature average value AVE (T1, T2, T3) <= (temperature setting value T9 + static zone temperature value + temperature bandwidth value), the inter-row air conditioner EC fan adjusts the fan speed in proportion.

2. The method according to claim 1, wherein the method is characterized by: The delay time in the step S1 ranges from 30s to 90s.

3. The method of claim 1, wherein the method further comprises: The cold aisle temperature protection value T7 in the step S2 ranges from 30 to 45℃.

4. The method of claim 1, wherein the method further comprises: The return air temperature setting value T8 in the step S3 ranges from 28 to 40℃.

5. The method of claim 1, wherein the method further comprises: The unbalanced temperature difference setting value T9 in the step S4 ranges from 3 to 10℃.

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