Indirect evaporative cooling air conditioning unit compressor start control method and system

Abstract

The application discloses a kind of indirect evaporative cooling air conditioning unit compressor starting control method and system, air conditioning unit has at least two working frequency variable compressor, control method includes: obtaining the indoor air outlet temperature of air conditioning unit;Temperature deviation value is calculated in current period and last period, temperature deviation value is the difference between indoor air outlet temperature and preset target temperature;The difference between temperature deviation value in current period and temperature deviation value in last period is calculated to obtain temperature deviation change rate;According to the required compressor quantity and frequency of current starting according to temperature deviation value in current period and temperature deviation change rate.Combining the above control method of the application, air conditioning unit starts compressor once in place, realizes the capacity output of air conditioning unit fast response, improves the energy efficiency of air conditioning unit, avoids compressor frequent start-stop.

Description

Technical Field

[0001] This invention relates to the field of multi-compressor air conditioning control technology, and in particular to a method and system for starting up an indirect evaporative cooling air conditioning unit compressor. Background Technology

[0002] In the field of central air conditioning, indirect evaporative cooling units are a common type of air conditioning cooling system used in data centers. An indirect evaporative cooling unit consists of a spray system, heat exchange core, indoor fans, outdoor fans, mechanical refrigeration supplementary equipment, and a control system. When using this unit, only the ductwork, water pipes, and power distribution need to be installed on-site at the data center before it can be put into operation. The unit has three operating modes: dry mode, wet mode, and mixed mode.

[0003] Dry mode uses natural cooling for heat exchange and is generally used in winter when temperatures are low. In winter, the outdoor air temperature is low enough to cool the server room return air within the heat exchanger. After passing through the heat exchanger, the outdoor air that has absorbed heat is exhausted outdoors through the fan wall. The cooled server room return air is then sent back into the server room through the indoor fan wall.

[0004] In wet mode, heat exchange is based on evaporative cooling. In spring and autumn when the outdoor temperature is low, the water pump needs to be turned on to supplement the cooling capacity by using high-pressure micro-mist spray for adiabatic evaporative cooling.

[0005] In hybrid mode, heat exchange is achieved through mechanical cooling. In summer, when outdoor temperatures are high, natural cooling is insufficient to meet cooling demands. Circulating water spray removes some heat, and for the remaining amount, the inverter compressor refrigeration system is activated to supplement the cooling capacity.

[0006] In hybrid mode, according to the current control method, when a compressor needs to be started, one compressor is usually started first, and then more compressors are started one by one according to energy demand. That is, the number of compressors in operation is increased gradually, and the operating frequency of the compressors is also gradually increased from the lowest level. Although the control process is simple, this control method results in slow improvement of the cooling capacity of the air conditioning unit, long control cycles, and a tendency for frequent compressor start-stop, which leads to a poor user experience. Summary of the Invention

[0007] The purpose of this invention is to provide a compressor start-up control method and system for an indirect evaporative cooling air conditioning unit that can start a corresponding number of compressors and compressor start-up frequency as needed.

[0008] To achieve the above objectives, this invention discloses a compressor start-up control method for an indirect evaporative cooling air conditioning unit, wherein the air conditioning unit has at least two compressors with variable operating frequencies, and the control method includes:

[0009] Obtain the indoor air outlet temperature of the air conditioning unit;

[0010] Calculate the temperature deviation between the current cycle and the previous cycle, where the temperature deviation is the difference between the indoor air outlet temperature and the preset target temperature;

[0011] Calculate the difference between the temperature deviation value of the current cycle and the temperature deviation value of the previous cycle to obtain the temperature deviation change rate;

[0012] Calculate the number and frequency of compressors that need to be started based on the current cycle's temperature deviation value and the rate of change of the temperature deviation.

[0013] Preferably, for the air conditioning unit with two compressors, the method for calculating the number and frequency of compressors to be started based on the current cycle temperature deviation value P and the temperature deviation change rate η includes:

[0014] When A≤P≤B, one of the compressors is started at a first preset frequency;

[0015] When P > B and η < k, the two compressors are started at the second preset frequency;

[0016] When P > B and η ≥ k, one of the compressors is started at a first preset frequency;

[0017] Wherein, 1≤A≤2, 2≤B≤3, 0.3≤K≤0.8, and the first preset frequency is greater than the second preset frequency.

[0018] Preferably, A = 1.5, B = 2.5, and K = 0.5.

[0019] Preferably, the first preset frequency is 40Hz and the second preset frequency is 35Hz.

[0020] Preferably, for the air conditioning unit with four compressors, the method for calculating the number of compressors to be started and the frequency based on the current cycle temperature deviation value P and the temperature deviation change rate η includes:

[0021] When A≤P≤B, one of the compressors is started at a first preset frequency;

[0022] When B < P ≤ C and η < k, both compressors are started simultaneously at the second preset frequency;

[0023] When B < P ≤ C and η ≥ k, one of the compressors is started at a first preset frequency;

[0024] When P > C and η < k, the three compressors are started simultaneously at the third preset frequency;

[0025] When P > C and η ≥ k, both compressors are started simultaneously at the second preset frequency;

[0026] Wherein, 1≤A≤2, 2≤B≤3, 3≤C≤4, 0.3≤K≤0.8, the first preset frequency is greater than the second preset frequency, and the second preset frequency is greater than the third preset frequency.

[0027] Preferably, A = 1.5, B = 2.5, K = 0.5, and C = 3.5.

[0028] Preferably, the first preset frequency is 40Hz, the second preset frequency is 35Hz, and the third preset frequency is 30Hz.

[0029] The present invention also discloses a compressor start-up control system for an indirect evaporative cooling air conditioning unit, which controls the start-up of the compressor in the air conditioning unit based on the above-mentioned compressor start-up control method for an indirect evaporative cooling air conditioning unit.

[0030] This invention also discloses a compressor start-up control system for an air conditioning unit, comprising:

[0031] One or more processors;

[0032] Memory;

[0033] 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, the programs including instructions for performing the air conditioning unit compressor start-up control method as described above.

[0034] The present invention also discloses a computer-readable storage medium, characterized in that it includes a computer program, which can be executed by a processor to perform the air conditioning unit compressor start-up control method as described above.

[0035] Compared with the prior art, the control method disclosed in the above-mentioned solution of the present invention is used to control the starting of multiple compressors in an air conditioning unit. The above-mentioned control method abandons the traditional control method of gradually increasing the number of compressors. Instead, it calculates the number and frequency of compressors to be started based on the current energy demand and the actual load of the air conditioning unit, that is, based on the temperature deviation value of the current cycle and the temperature deviation change rate. This allows the air conditioning unit to start the compressors in one go, realizes the rapid response of the air conditioning unit's capacity output, improves the energy efficiency of the air conditioning unit, and avoids frequent start-stop of the compressors. Attached Figure Description

[0036] Figure 1 This is a flowchart of the control method in an embodiment of the present invention.

[0037] Figure 2 This is a structural diagram showing the arrangement of multiple compressors in one embodiment of the present invention. Detailed Implementation

[0038] To illustrate the technical content, structural features, objectives, and effects of the present invention in detail, the following description is provided in conjunction with the embodiments and accompanying drawings.

[0039] This embodiment discloses a compressor start-up control method for an air conditioning unit. The air conditioning unit in this embodiment operates based on indirect evaporative cooling technology and includes dry mode, wet mode, and mixed mode. The compressor is only started when the air conditioning unit is operating in mixed mode. Therefore, the control method in this embodiment is for the air conditioning unit operating in mixed mode. Moreover, the air conditioning unit has multiple (at least two) compressors with variable operating frequencies. The control method is used to control the number of compressors started and the start-up frequency when starting the compressor.

[0040] like Figure 1 The control method includes the following steps:

[0041] S1: Obtain the indoor air outlet temperature of the air conditioning unit;

[0042] S2: Calculate the temperature deviation between the current cycle and the previous cycle. The temperature deviation is the difference between the indoor air outlet temperature and the preset target temperature.

[0043] S3: Calculate the difference between the temperature deviation value of the current cycle and the temperature deviation value of the previous cycle to obtain the temperature deviation change rate;

[0044] S4: Calculate the number and frequency of compressors that need to be started based on the current cycle's temperature deviation value and temperature deviation change rate.

[0045] It should also be noted that the control method in this embodiment controls the compressor start-up process of the air conditioning unit to enter the mixed mode, rather than the compressor operation process. In other words, after the compressor starts up, the operation of the compressor can be controlled according to the control mode known to those skilled in the art.

[0046] Specifically, for an air conditioning unit with two compressors, the methods for calculating the number and frequency of compressors to be started based on the current cycle temperature deviation value P and the temperature deviation change rate η include:

[0047] When A≤P≤B, one of the compressors is started at the first preset frequency;

[0048] When P > B and η < k, the two compressors are started at the second preset frequency;

[0049] When P > B and η ≥ k, one of the compressors is started at the first preset frequency;

[0050] Where 1≤A≤2, 2≤B≤3, 0.3≤K≤0.8, the first preset frequency is greater than the second preset frequency. More specifically, A=1.5, B=2.5, K=0.5, the first preset frequency is 40Hz, and the second preset frequency is 35Hz.

[0051] According to the control method in this embodiment, during the operation of the air conditioning unit, when the unit is in wet mode, the indoor air outlet temperature is detected in real time and compared with a preset target temperature to obtain two indicators: the temperature deviation value and the rate of change of temperature deviation for the current period. Based on these two indicators, the number and frequency of compressors currently running simultaneously are determined, enabling the air conditioning unit to quickly meet current energy needs. However, once the air conditioning unit starts its compressors and enters mixed mode, the above control method is no longer executed.

[0052] On the other hand, for an air conditioning unit with four compressors, the methods for calculating the number and frequency of compressors to be started based on the current cycle temperature deviation value P and the temperature deviation change rate η include:

[0053] When A≤P≤B, one of the compressors is started at the first preset frequency;

[0054] When B < P ≤ C and η < k, the two compressors are started simultaneously at the second preset frequency;

[0055] When B < P ≤ C and η ≥ k, start a compressor at the first preset frequency;

[0056] When P > C and η < k, the three compressors are started simultaneously at the third preset frequency;

[0057] When P > C and η ≥ k, both compressors are started simultaneously at the second preset frequency.

[0058] Wherein, 1≤A≤2, 2≤B≤3, 3≤C≤4, 0.3≤K≤0.8, the first preset frequency is greater than the second preset frequency, and the second preset frequency is greater than the third preset frequency.

[0059] Specifically, in this embodiment, A = 1.5, B = 2.5, K = 0.5, C = 3.5, the first preset frequency is 40Hz, the second preset frequency is 35Hz, and the third preset frequency is 30Hz.

[0060] For the two specific embodiments described above, in wet mode, when P < A, it means that the current energy demand of the air conditioning unit is met, and there is no need to turn on the compressor. When P ≥ A, the choice is made to turn on one or more compressors based on other conditions. Moreover, the starting frequency of the compressors also varies depending on the number of compressors turned on.

[0061] In addition, for air conditioning units with four compressors, according to the above control method, a maximum of three compressors can be started at the same time to prevent overshoot caused by the simultaneous start of four compressors, effectively ensuring the safe operation of the air conditioning unit.

[0062] On the other hand, when selecting to start the compressor, start one, two, or three compressors with the shortest current running time, thereby effectively extending the compressor's lifespan.

[0063] On the other hand, for multiple compressors in an air conditioning unit, they can be grouped in pairs, that is, two compressors can share a single condenser (e.g., Figure 2 Of course, without considering manufacturing costs, each compressor can also be configured separately, that is, each compressor can be configured with a condenser.

[0064] In summary, the control method disclosed in the above embodiments of the present invention abandons the traditional control method of gradually increasing the number of compressors. Instead, it calculates the number and frequency of compressors to be started based on the current energy demand and the actual load of the air conditioning unit, that is, based on the temperature deviation value and the temperature deviation change rate of the current cycle. This allows the air conditioning unit to start the compressors in one go, realizes the rapid response of the air conditioning unit's capacity output, improves the energy efficiency of the air conditioning unit, and avoids frequent start-stop of the compressors.

[0065] In another preferred embodiment of the present invention, a compressor start-up control system for an indirect evaporative cooling air conditioning unit is also disclosed, which controls the start-up of the compressor in the air conditioning unit based on the above-described control method.

[0066] The present invention also discloses another compressor start-up control system, which includes 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. The programs include instructions for performing the compressor start-up control method as described above. The processor may be a general-purpose central processing unit (CPU), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits, used to execute the relevant programs to implement the functions required by the modules in the compressor start-up control system of the embodiments of this application, or to execute the compressor start-up control method of the method embodiments of this application.

[0067] This invention also discloses a computer-readable storage medium comprising a computer program executable by a processor to perform the compressor start-up control method described above. The computer-readable storage medium can be any available medium accessible to a computer or a data storage device such as a server or data center integrating one or more available media. The available medium can be read-only memory (ROM), random access memory (RAM), or magnetic media, such as floppy disks, hard disks, magnetic tapes, magnetic disks, or optical media, such as digital versatile discs (DVDs), or semiconductor media, such as solid-state disks (SSDs).

[0068] This application also discloses a computer program product or computer program, which includes computer instructions stored in a computer-readable storage medium. The processor of an electronic device reads the computer instructions from the computer-readable storage medium and executes the computer instructions, causing the electronic device to perform the aforementioned compressor start-up control method.

[0069] The above-disclosed embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of the present invention. Therefore, any equivalent variations made in accordance with the claims of the present invention are still within the scope of the present invention.

Claims

1. A method for starting and controlling the compressor of an indirect evaporative cooling air conditioning unit, wherein the air conditioning unit has at least two compressors with variable operating frequencies, characterized in that, The control method includes: Obtain the indoor air outlet temperature of the air conditioning unit; Calculate the temperature deviation between the current cycle and the previous cycle, where the temperature deviation is the difference between the indoor air outlet temperature and the preset target temperature; Calculate the difference between the temperature deviation value of the current cycle and the temperature deviation value of the previous cycle to obtain the temperature deviation change rate; Calculate the number and frequency of compressors that need to be started based on the current cycle temperature deviation value and the temperature deviation change rate; For the air conditioning unit with two compressors, the method for calculating the number and frequency of compressors to be started based on the current cycle temperature deviation value P and the temperature deviation change rate η includes: When A≤P≤B, one of the compressors is started at a first preset frequency; When P > B and η < k, the two compressors are started at the second preset frequency; When P > B and η ≥ k, one of the compressors is started at a first preset frequency; Wherein, 1≤A≤2, 2≤B≤3, 0.3≤K≤0.8, and the first preset frequency is greater than the second preset frequency.

2. The compressor start-up control method for an indirect evaporative cooling air conditioning unit according to claim 1, characterized in that, A=1.5, B=2.5, K=0.

5.

3. The compressor start-up control method for an indirect evaporative cooling air conditioning unit according to claim 1, characterized in that, The first preset frequency is 40Hz, and the second preset frequency is 35Hz.

4. The compressor start-up control method for an indirect evaporative cooling air conditioning unit according to claim 1, characterized in that, For the air conditioning unit with four compressors, the method for calculating the number and frequency of compressors to be started based on the current cycle temperature deviation value P and the temperature deviation change rate η includes: When A≤P≤B, one of the compressors is started at a first preset frequency; When B < P ≤ C and η < k, both compressors are started simultaneously at the second preset frequency; When B < P ≤ C and η ≥ k, one of the compressors is started at a first preset frequency; When P > C and η < k, the three compressors are started simultaneously at the third preset frequency; When P > C and η ≥ k, both compressors are started simultaneously at the second preset frequency; Wherein, 1≤A≤2, 2≤B≤3, 3≤C≤4, 0.3≤K≤0.8, the first preset frequency is greater than the second preset frequency, and the second preset frequency is greater than the third preset frequency.

5. The compressor start-up control method for an indirect evaporative cooling air conditioning unit according to claim 4, characterized in that, A=1.5, B=2.5, K=0.5, C=3.

5.

6. The compressor start-up control method for an indirect evaporative cooling air conditioning unit according to claim 4, characterized in that, The first preset frequency is 40Hz, the second preset frequency is 35Hz, and the third preset frequency is 30Hz.

7. A compressor start-up control system for an indirect evaporative cooling air conditioning unit, characterized in that, The control system controls the start-up of the compressor in the air conditioning unit based on the compressor start-up control method of any one of claims 1 to 6.

8. A compressor start-up control system for an air conditioning unit, characterized in that, include: One or more processors; 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, the programs including instructions for performing the compressor start-up control method for an indirect evaporative cooling air conditioning unit as described in any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that, Includes a computer program that can be executed by a processor to perform the compressor start-up control method for an indirect evaporative cooling air conditioning unit as described in any one of claims 1 to 6.

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