A control method and device for air conditioning system

Abstract

This application discloses a control method and apparatus for an air conditioning system. The method includes: determining that the air conditioning system meets set entry conditions for a water-cooled storage mode, and controlling the air conditioning system to enter the water-cooled storage mode. The entry conditions include the air conditioning system being in a low-load operating state and the chilled water return temperature being lower than a set entry mode temperature. The method also includes: determining that the air conditioning system meets set exit conditions for the water-cooled storage mode, and controlling the air conditioning system to exit the water-cooled storage mode. The exit conditions include the chilled water return temperature being higher than a set exit mode temperature. The set entry mode temperature is lower than the set exit mode temperature.

Description

Technical Field

[0001] The present application relates to the technical field of air conditioning, and in particular to a control method and device for an air conditioning system. Background Art

[0002] Air conditioning system plays an extremely important role in improving the indoor environment of buildings and ensuring the comfort of indoor personnel. In large public buildings, the energy consumption of air conditioning system accounts for more than 50% of the total energy consumption of buildings, which is the main energy consumption in buildings. Therefore, the energy-saving optimization of HVAC system is of great significance to the overall energy saving of buildings. In the transition season and winter, the outdoor temperature is low. For buildings that still have a small demand for cooling, the air conditioning system will be in a low-load operation state at this time, and the chiller may start and stop frequently. When the air conditioning host enters the pause state, the chilled water pump, cooling water pump and cooling tower in the air conditioning system will still remain in operation, which will increase the energy consumption of the air conditioning system. Summary of the invention

[0003] The embodiments of the present application provide a control method and device for an air-conditioning system, which reduces the energy consumption of the air-conditioning system by controlling the air-conditioning system to enter and exit a water storage cooling mode.

[0004] The solution provided by the embodiment of the present application is as follows: a control method of an air conditioning system, the method comprising:

[0005] Determining that the air conditioning system meets the set entry conditions of the water cooling storage mode, and controlling the air conditioning system to enter the water cooling storage mode, wherein the entry conditions include that the air conditioning system is in a low-load operation state, and the chilled water return temperature is less than the set entry mode temperature;

[0006] Determining that the air conditioning system meets a set exit condition of the water cooling storage mode, and controlling the air conditioning system to exit the water cooling storage mode, wherein the exit condition includes that the chilled water return temperature is greater than a set exit mode temperature;

[0007] The set entry mode temperature is lower than the set exit mode temperature.

[0008] In an exemplary embodiment, determining that the air conditioning system is in a low-load operating state includes:

[0009] In the fully automatic mode, when the number of currently running hosts is 1, the currently running host is the host with the smallest capacity among the fault-free hosts, and the host load rate is lower than the set minimum load rate, it is determined that the air-conditioning system is in a low-load operation state.

[0010] In an exemplary embodiment, determining that the air conditioning system is in a low-load operating state includes:

[0011] In the semi-automatic mode, when the current number of host machines in operation is 1 and the host load rate is lower than the set minimum load rate, it is determined that the air-conditioning system is in a low-load operation state.

[0012] In an exemplary embodiment, after controlling the air-conditioning system to enter the water storage cooling mode, the method also includes: recording the operating time of the air-conditioning system in the water storage cooling mode, and when the operating time does not meet the set time requirement, determining an entry mode temperature that can meet the time requirement, and updating the set entry mode temperature to the entry mode temperature that can meet the time requirement.

[0013] In an exemplary embodiment, determining the entry mode temperature that can meet the duration requirement includes:

[0014] According to the set duration in the water storage cooling mode, the entry mode temperature and the exit mode temperature when entering the water storage cooling mode, the chilled water return temperature optimization model is used to determine the entry mode temperature that can meet the duration requirements;

[0015] Among them, the optimization model of the chilled water return temperature is:

[0016]

[0017] In the formula, t s is the duration of the water storage cooling mode, t k is the operation time in the water storage cooling mode, a is the fitting coefficient, T 1,k is the entry mode temperature when entering the water storage cooling mode, T 1,s T2 is the entry mode temperature that meets the duration requirement, and T3 is the exit mode temperature.

[0018] In an exemplary embodiment, the method further includes: when the air-conditioning system is in a low-load operating state but the air-conditioning system has not entered the water storage cooling mode within the maximum allowed waiting time, increasing the set entry mode temperature so that the air-conditioning system can enter the water storage cooling mode.

[0019] In an exemplary embodiment, the step of increasing the set entry mode temperature includes:

[0020] The target outlet water temperature setting value of the host at the current moment is calculated according to the temperature increase model to obtain the set entry mode temperature after the increase;

[0021] updating the increased set entry mode temperature as the entry mode temperature;

[0022] Among them, the temperature increase model is:

[0023] T 1,k =Ts,k +d

[0024] Where, T 1,k is the entry mode temperature set this time, T s,k is the target outlet water temperature setting value of the host at the current moment, and d is a constant.

[0025] In an exemplary embodiment, after raising the set entry mode temperature so that the air-conditioning system enters the water storage cooling mode, the method further includes: recording the operating time of the air-conditioning system in the water storage cooling mode, and when the operating time does not meet the set time requirement, determining the entry mode temperature that can meet the time requirement, updating the set entry mode temperature to the entry mode temperature that can meet the time requirement, and lowering the host target water outlet temperature setting value.

[0026] In an exemplary embodiment, lowering the target outlet water temperature setting value of the host includes:

[0027] According to the entry mode temperature that meets the time requirement, the host target water outlet temperature setting value at the current moment, and the entry mode temperature set this time, the host target water outlet temperature setting value after the adjustment is obtained by adjusting the model;

[0028] Among them, the lowering model is:

[0029] T s,k+1 =T s，k -b(T 1,k -T 1,s )-c

[0030] Where, T s,k+1 is the lowered target outlet water temperature setting value of the host, T s,k is the target outlet water temperature setting value of the host at the current moment, T 1,k is the entry mode temperature set this time, T 1,s The entry mode temperature to meet the duration requirement.

[0031] The present application also provides a control device for an air conditioning system, the device comprising: a memory and a processor; the memory is used to store a program for controlling the air conditioning system, the processor is used to read and execute the program for controlling the air conditioning system, and execute any one of the methods in the above embodiments.

[0032] The embodiment of the present application discloses a control method and device for an air conditioning system, the method comprising: determining that the air conditioning system meets the set entry conditions of a water-cooled storage mode, controlling the air conditioning system to enter the water-cooled storage mode, the entry conditions comprising that the air conditioning system is in a low-load operation state, and the chilled water return temperature is less than the set entry mode temperature; determining that the air conditioning system meets the set exit conditions of the water-cooled storage mode, controlling the air conditioning system to exit the water-cooled storage mode, the exit conditions comprising that the chilled water return temperature is greater than the set exit mode temperature; wherein the set entry mode temperature is lower than the set exit mode temperature. The present application reduces the energy consumption of the air conditioning system by entering and exiting the water-cooled storage mode.

[0033] Other aspects will be apparent upon reading and understanding the drawings and detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0035] Figure 1 This is a flow chart of a control method for an air conditioning system in Example 1 of the present application;

[0036] Figure 2 A schematic diagram of the operating status of system equipment in different modes in an example;

[0037] Figure 3 This is a control logic diagram for entering water storage cooling mode in an example;

[0038] Figure 4 A flow chart for optimizing parameters of water storage cooling mode in an example;

[0039] Figure 5 This is a schematic diagram of the control logic for exiting the water storage cooling mode in an example;

[0040] Figure 6 This is a graph showing the number of starts and stops of the air conditioner host in a single day under different operating modes in an example;

[0041] Figure 7 This is a schematic diagram of a control device for an air-conditioning system according to Example 3 of the present application. DETAILED DESCRIPTION

[0042] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions 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 are within the scope of protection of this application.

[0043] It should be noted that all directional indications in the embodiments of the present application (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0044] In addition, in the present application, descriptions such as "first", "second", etc. are only used to distinguish things or behaviors with the same name, etc., and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0045] In this application, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0046] In addition, the technical solutions between the various embodiments of the present application can be combined with each other, but it must be based on the fact that ordinary technicians in the field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0047] Example 1

[0048] This embodiment provides a control method for an air conditioning system. Figure 1 As shown, the control method of the air conditioning system includes steps S100-S110, which are specifically as follows:

[0049] S100. Determine that the air conditioning system meets the set entry conditions of the water-cooled storage mode, and control the air conditioning system to enter the water-cooled storage mode, wherein the entry conditions include that the air conditioning system is in a low-load operation state, and the chilled water return temperature is less than the set entry mode temperature;

[0050] S110. Determine that the air conditioning system meets the set exit condition of the water cooling storage mode, and control the air conditioning system to exit the water cooling storage mode. The exit condition includes that the chilled water return temperature is greater than the set exit mode temperature.

[0051] In this embodiment, the operating status of each module in the air conditioning system in the normal operation mode of the air conditioning system changes as follows: Figure 2 As shown; in the normal operation mode, when the cooling load demand of the air-conditioning system is low, the chiller of the air-conditioning system will operate at a lower load rate. After the air-conditioning host runs for a short time, the water supply temperature of the chilled water reaches the temperature value at which the air-conditioning host enters the pause state, and the air-conditioning host will shut down and enter the pause state; after a period of cooling, the chilled water temperature rises to the exit pause set temperature, and the air-conditioning host will restart and perform cooling. In the normal operation mode of the air-conditioning system, when the host is paused, the freezing pump, cooling pump and cooling tower of the air-conditioning system remain in operation. Therefore, in this operation mode, when the cooling load at the end of the air-conditioning system is small, the pause time of the air-conditioning host will be longer. When the air-conditioning host is paused, the power consumption of the cooling end equipment in the air-conditioning system is useless, which will increase the overall energy consumption of the air-conditioning system.

[0052] In an exemplary embodiment, the air conditioning system enters the water storage cooling mode, including: running the refrigeration pump, shutting down the host, cooling pump and cooling tower. The air conditioning system exits the water storage cooling mode, including: running the refrigeration pump, host, cooling pump and cooling tower. In this embodiment, the operating state changes of each module in the air conditioning system when the air conditioning system enters the water storage cooling mode and exits the water storage cooling mode are as follows: Figure 2As shown in the figure, in the water storage cooling operation mode, the air conditioning system will shut down the air conditioning host, the cooling pump and the cooling tower, and only keep the freezing pump open, relying on the freezing pump to circulate the low-temperature chilled water prepared before the air conditioning host is shut down to the terminal for cooling. The control process of the water storage cooling mode is: after the air conditioning host is running at a low load rate and the system's chilled return water temperature continues to drop to reach the set temperature for entering the water storage cooling mode, it will run for a period of time to control the air conditioning system to enter the water storage cooling mode. After determining that the air conditioning system has entered the water storage cooling mode, shut down the air conditioning host, the cooling pump, the cooling tower and the corresponding valves, and only keep the freezing pump running, relying on the freezing pump to transport the low-temperature chilled water prepared before the air conditioning host is shut down to the terminal for cooling. After the air-conditioning system has been running in the water storage cooling mode for a period of time, the water temperature of the chilled water in the main pipe of the air-conditioning system will continue to rise due to the terminal heat exchange. When the chilled water return temperature rises to the set temperature for exiting the water storage cooling mode, the air-conditioning system will run for a period of time and then exit the water storage cooling mode. At this time, the air-conditioning system will restart the cooling pump, turn on the cooling tower and the corresponding valves, and finally restart the air-conditioning host for cooling.

[0053] In the air-conditioning system, the chilled water return temperature can directly reflect the size of the terminal load of the air-conditioning system. The energy consumption of the air-conditioning system can be calculated by the following formula:

[0054] P sys =P ch +P chwp +P cwp +P ct

[0055] Where P sys is the energy consumption of the computer room, P ch is the energy consumption of the air conditioner host, P chwp is the energy consumption of the chilled water pump, P cwp is the energy consumption of cooling water pump, P ct is the energy consumption of cooling tower.

[0056] Compared with the normal operation mode of the air conditioning system, the water storage cooling mode can extend the downtime of the air conditioning host, shut down the cooling water pump and cooling tower when the air conditioning host is shut down, and reduce the energy consumption of the cooling water pump. cwp and cooling tower energy consumption P ct , thereby reducing the total energy consumption of the computer room P sys , achieving energy-saving effect.

[0057] In an exemplary embodiment, low load is to determine that the air-conditioning system is in a low-load operating state, including: in full-automatic mode, when the current number of running hosts is 1, the currently running host is the host with the smallest capacity among the fault-free hosts, and the host load rate is lower than the set minimum load rate, the air-conditioning system is determined to be in a low-load operating state. The set entry mode temperature is lower than the set exit mode temperature. For example: the set entry mode temperature is 2°C, and the set exit mode temperature is 12°C. Determining that the air-conditioning system is in a low-load operating state includes: in semi-automatic mode, when the current number of running hosts is 1, and the host load rate is lower than the set minimum load rate, the air-conditioning system is determined to be in a low-load operating state. In this embodiment, the air-conditioning system has a fully automatic mode and a semi-automatic mode. For different modes, the process of controlling the air-conditioning system to enter the water storage cooling mode is respectively:

[0058] In an exemplary embodiment, the air conditioning system is in full automatic mode, and the process of controlling the air conditioning system to enter the water storage cooling mode is:

[0059] Step 1. Make sure the air conditioning system is in full automatic mode;

[0060] Step 2. Determine that the current number of operating air-conditioning hosts is 1, and the operating air-conditioning host is a host with the smallest cooling capacity and no faults in the air-conditioning system;

[0061] Step 3. Obtaining the operating data of the air conditioning system within a preset time period;

[0062] Step 4. Determine, based on the operation data of the air conditioning system, that the load rate of the current air conditioning host is lower than the set value of the minimum load rate of the air conditioning host and the return water temperature of the chilled water of the air conditioning system is lower than the set entry mode temperature;

[0063] Step 5: Determine that the air conditioning system enters the water storage cooling mode.

[0064] In an exemplary embodiment, the air conditioning system is in semi-automatic mode, and the process of the air conditioning system entering the water storage cooling mode is:

[0065] Step 1. Make sure the air conditioning system is in semi-automatic mode;

[0066] Step 2. Determine that the current number of running air conditioner hosts is 1;

[0067] Step 3. Obtaining the operating data of the air conditioning system within a preset time period;

[0068] Step 4. Determine, based on the operation data of the air conditioning system, that the load rate of the current air conditioning host is lower than the set value of the minimum load rate of the air conditioning host and the return water temperature of the chilled water of the air conditioning system is lower than the set entry mode temperature;

[0069] Step 5: Determine that the air conditioning system enters the water storage cooling mode.

[0070] In an exemplary embodiment, the steps of the air conditioning system entering the water storage cooling mode are as follows: Figure 3 As shown, it can be divided into 5 steps:

[0071] Step 1: Determine whether the current operating mode of the system is fully automatic mode or semi-automatic mode;

[0072] Step 2: Determine whether the number of hosts currently in operation is 1. If it is 1, proceed to the next step. Otherwise, the program ends and the system does not take any action.

[0073] Step 3: If the system operation mode in step 1 is the fully automatic mode, determine whether the host in operation is the air-conditioning host with no faults and the smallest capacity in the entire system. If so, proceed to the next step, otherwise, end the program and the system does not take any action; if the system operation mode in step 1 is the semi-automatic mode, proceed to the next step;

[0074] Step 4: Determine whether the load rate of the air-conditioning host in current operation is lower than the minimum load rate setting value of the air-conditioning host and whether the chilled water return temperature of the air-conditioning system is lower than the predetermined entry mode temperature T1. For example: the predetermined entry mode temperature T1 is 12 degrees Celsius; the minimum load rate setting value of the air-conditioning host is 20% to 30%, and the predetermined entry mode temperature can also be changed according to the actual project operation conditions. The entry mode temperature T1 is the set temperature for the air-conditioning system to enter the water storage mode. The size of the entry mode temperature setting value has an important influence on the duration of the air-conditioning host entering the water storage mode, and when the terminal load changes, the entry mode temperature value needs to be changed to keep the system able to enter the water storage mode. Among them, the relationship between the size of the entry mode temperature value and the duration of the air-conditioning host maintaining the operation of the water storage mode is: during the rise of the chilled water return temperature, the rise time of the chilled water return temperature is exponentially related to the difference between the entry mode temperature and the exit mode temperature of the water storage mode, and the relationship is:

[0075]

[0076] In the formula, t is the time that the air conditioner host maintains the water storage cooling mode, that is, the temperature rise time, a is the fitting coefficient, T1 is the entry mode temperature of the water storage cooling mode, and T2 is the entry mode temperature of the water storage cooling mode. The fitting coefficient a can be obtained by fitting multiple sets of T1 and T2 values.

[0077] Step 5: If all the above conditions are met, and the conditions are met for more than N1 minutes, the system enters the water storage mode, and the water storage mode flag can be triggered. After obtaining the water storage mode flag signal, the system control program first shuts down the air conditioner host, waits for the air conditioner host to complete shutdown and enter the standby state, then shuts down the cooling pump and cooling tower, and finally closes the corresponding valves, leaving only the refrigeration pump running; in the water storage mode, the refrigeration pump continuously circulates the low-temperature chilled water prepared before the air conditioner host is shut down to supply cooling to the terminal.

[0078] In an exemplary embodiment, in the water storage cooling mode, the settings of parameters such as the entry mode temperature and the exit mode temperature have a great impact on the overall operation and energy saving of the air conditioning system. Different setting parameters may cause the air conditioning system to be unable to enter the water storage cooling mode or to operate in the water storage cooling mode for a short time, and the air conditioning host still has the phenomenon of frequent start and stop. In order to improve the above two operating states and enable the air conditioning system to maintain a more ideal water storage cooling mode state, the setting parameters of the water storage cooling mode are optimized.

[0079] In an exemplary embodiment, after the air conditioning system is controlled to enter the water storage cooling mode, the operating time of the air conditioning system in the water storage cooling mode is recorded. If the operating time does not meet the set time requirement, the entry mode temperature that can meet the time requirement is determined, and the set entry mode temperature is updated to the entry mode temperature that can meet the time requirement. For example: the current entry mode temperature is 5°C, the current operation time in the water storage cooling mode is 40 minutes, and the set time requirement is 60 minutes. By adjusting the time when the entry mode temperature is 3°C to 70 minutes, the adjusted 3°C is updated to the entry mode temperature that can meet the time requirement.

[0080] In an exemplary embodiment, the determining of the entry mode temperature that can meet the duration requirement includes: determining the entry mode temperature that can meet the duration requirement by using a chilled water return temperature optimization model according to the set duration in the water storage cooling mode, the entry mode temperature in the current entry into the water storage cooling mode, and the exit mode temperature;

[0081] Among them, the optimization model of the chilled water return temperature is:

[0082]

[0083] In the formula, t s is the duration of the water storage cooling mode, t k is the operation time in the water storage cooling mode, a is the fitting coefficient, T 1,k is the entry mode temperature when entering the water storage cooling mode, T 1,s T2 is the entry mode temperature that meets the duration requirement, and T3 is the exit mode temperature.

[0084] In an exemplary embodiment, the method further includes: when the air-conditioning system is in a low-load operating state but the air-conditioning system has not entered the water storage cooling mode within the maximum allowed waiting time, increasing the set entry mode temperature so that the air-conditioning system can enter the water storage cooling mode.

[0085] In an exemplary embodiment, the step of increasing the set entry mode temperature includes:

[0086] The target outlet water temperature setting value of the host at the current moment is calculated according to the temperature increase model to obtain the set entry mode temperature after the increase;

[0087] updating the increased set entry mode temperature as the entry mode temperature;

[0088] Among them, the temperature increase model is:

[0089] T 1,k =T s,k +d

[0090] Where, T 1,k is the entry mode temperature set this time, T s,k is the target outlet water temperature setting value of the host at the current moment, and d is a constant.

[0091] In an exemplary embodiment, after raising the set entry mode temperature so that the air-conditioning system enters the water storage cooling mode, the method further includes: recording the operating time of the air-conditioning system in the water storage cooling mode, and when the operating time does not meet the set time requirement, determining the entry mode temperature that can meet the time requirement, updating the set entry mode temperature to the entry mode temperature that can meet the time requirement, and lowering the host target water outlet temperature setting value.

[0092] In an exemplary embodiment, lowering the target outlet water temperature setting value of the host includes:

[0093] According to the entry mode temperature that meets the time requirement, the host target water outlet temperature setting value at the current moment, and the entry mode temperature set this time, the host target water outlet temperature setting value after the adjustment is obtained by adjusting the model;

[0094] Among them, the lowering model is:

[0095] T s,k+1 =T s，k -b(T 1,k -T 1,s )-c

[0096] Where, T s,k+1is the lowered target outlet water temperature setting value of the host, T s,k is the target outlet water temperature setting value of the host at the current moment, T 1,k is the entry mode temperature set this time, T 1,s The entry mode temperature to meet the duration requirement.

[0097] In an exemplary embodiment, in the water storage cooling mode, the settings of parameters such as the water storage cooling entry set temperature and the water storage cooling exit set temperature have a great impact on the overall operating status and energy saving of the air conditioning system. Different setting parameters may cause the air conditioning system to be unable to enter the water storage cooling mode or to operate in the water storage cooling mode for a short time, and the air conditioning host still has the phenomenon of frequent start and stop. In order to improve the above two operating conditions and enable the air conditioning system to maintain a more ideal water storage cooling mode state, the setting parameters of the water storage cooling mode are optimized; the water storage cooling mode parameter optimization process is as follows: Figure 4 As shown, including:

[0098] 400. Determine the parameters for entering the water storage cooling mode this time: T 1,k is the entry mode temperature when entering the water storage cooling mode, T 1,s The entry mode temperature satisfies the time requirement; determine whether to enter the water storage cooling mode, and proceed to 410; if not, proceed to 420;

[0099] 410. Enter water storage cooling mode; judge t k Is the running time in the water storage cooling mode greater than t s is the duration in the water storage cooling mode; if it is greater than, no parameter optimization is required; if it is less than, execute 430;

[0100] 430.t k The running time in the water storage cooling mode is less than t s The duration of the water storage cooling mode is set. That is, when the setting of the entry mode temperature T1 is set too high, the system will enter the water storage cooling mode for a short time and cannot achieve the ideal water storage cooling time, thus causing the host to frequently turn on and off. Therefore, it is necessary to optimize the entry mode temperature, and through the optimization value, the water storage cooling mode duration can reach the set value, according to the following relationship:

[0101]

[0102] In the formula, t s is the duration of the water storage cooling mode, t k is the operation time in the water storage cooling mode, a is the fitting coefficient, T 1,k is the entry mode temperature when entering the water storage cooling mode, T 1,s T2 is the entry mode temperature that meets the duration requirement, and T3 is the exit mode temperature.

[0103] According to the above formula, the duration of the water storage cooling mode can be calculated to reach the set duration t in the water storage cooling mode. s The entry mode temperature T in the water storage cooling mode under the condition 1,s .

[0104] 420. When the air conditioning system cannot enter the water storage cooling mode, the host is kept running at the minimum load for a long time, the entry mode temperature is optimized, and step 440 is executed;

[0105] 440. Calculate the host target outlet water temperature setting value at the current moment according to the temperature increase model to obtain the increased set entry mode temperature; update the increased set entry mode temperature as the entry mode temperature;

[0106] Among them, the temperature increase model is:

[0107] T 1,k =T s,k +d

[0108] Where, T 1,k is the entry mode temperature set this time, T s,k is the target outlet water temperature setting value of the host at the current moment, and d is a constant.

[0109] 450. The updated entry mode temperature T obtained in step 440 is determined 1,k Operating time in water storage mode t k Is it greater than the set time t? s If it is greater than, there is no need to optimize the parameters and the updated entry mode temperature T 1,k As the set temperature for entering the water storage cooling mode after reaching the set time, the temperature for entering the water storage cooling model for the next time; if it is less than, execute 460;

[0110] 460. The water storage cooling mode duration can reach the set value by optimizing the value, and the optimization is performed according to the following relationship:

[0111]

[0112] In the formula, t s is the duration of the water storage cooling mode, t k is the operation time in the water storage cooling mode, a is the fitting coefficient, T 1,k is the entry mode temperature when entering the water storage cooling mode, T 1,s T2 is the entry mode temperature that meets the duration requirement, and T3 is the exit mode temperature.

[0113] According to the above formula, the duration of the water storage cooling mode can be calculated to reach the set duration t in the water storage cooling mode.s The entry mode temperature T in the water storage cooling mode under the condition 1,s ; Further execute step 470.

[0114] 470. After obtaining the updated entry mode temperature, further optimize the host target outlet water temperature setting value to ensure that the air conditioning system can enter the water storage cooling mode next time under the current load condition. The implementation process is: according to the entry mode temperature that meets the time requirement, the host target outlet water temperature setting value at the current moment, and the entry mode temperature set this time, the host target outlet water temperature setting value after the adjustment is obtained by lowering the model;

[0115] Among them, the lowering model is:

[0116] T s,k+1 =T s，k -b(T 1,k -T 1,s )-c

[0117] Where, T s,k+1 is the lowered target outlet water temperature setting value of the host, T s,k is the target outlet water temperature setting value of the host at the current moment, T 1,k is the entry mode temperature set this time, T 1,s To meet the entry mode temperature required for the duration. After completing the optimization of the entry mode temperature T1 and the host target water outlet temperature setting value Ts, the air conditioning system will be in a relatively ideal intermittent start-stop operation state, which can meet the single water storage duration to reach the set value, and there will be no frequent start-stop of the host or the system cannot enter the water storage mode. This intermittent host operation state has a higher energy efficiency value than the original frequent start-stop and long-term low-load rate operation of the host, and can achieve the effect of energy saving and consumption reduction.

[0118] In an exemplary embodiment, if it is determined that the detected current chilled water return temperature is greater than the set exit mode temperature, then the water storage mode is exited, including: determining that the chilled water return temperature of the air-conditioning system is greater than the exit mode temperature, determining that the time interval between the current moment and the last shutdown moment of the air-conditioning host is greater than the length of a second time period, and then exiting the water storage mode.

[0119] The process of exiting the water cooling mode includes:

[0120] Make sure the air conditioning system is in full automatic mode;

[0121] Obtain an indication signal for exiting the water storage cooling mode and start the cooling tower and cooling pump;

[0122] Make sure the cooling pump and cooling tower are in operation, and turn on the air conditioner with the smallest capacity and no faults for cooling;

[0123] Make sure the air conditioning system is in semi-automatic mode;

[0124] Obtain an indication signal for exiting the water storage cooling mode and start the cooling tower and cooling pump;

[0125] Make sure the cooling pump and cooling tower are in operation, and turn on the air conditioning host in semi-automatic mode for cooling.

[0126] In an exemplary embodiment, the step of exiting the water storage cooling mode control is as follows: Figure 5 As shown:

[0127] Step 1: First determine whether the system is in water storage cooling operation mode. If it is satisfied, proceed to the next step. Otherwise, the program ends and the system does not take any action.

[0128] Step 2: Determine whether the system chilled water return temperature is greater than the exit mode temperature T2. If the condition is met for more than N2 minutes, proceed to the next step. If it is not met or the condition is met for less than N2 minutes, the program ends and the system does not take any action. The exit mode temperature T2 is the set temperature for the system to exit the water storage cooling mode. The higher the set value, the longer the host downtime. However, if the set value is too high, the system chilled water temperature will be too high, thus affecting the comfort of the end user.

[0129] Step 3: Determine whether the time interval between the current time and the last time the host was shut down is greater than N3 minutes. N3 is the minimum time for the system to enter the water storage cooling mode, which means that the system is allowed to exit the water storage cooling mode after entering the water storage cooling mode for at least N3 minutes.

[0130] Step 4: If all the above conditions are met, the system exits the water storage cooling mode, and the exit water storage cooling mode flag is triggered.

[0131] Step 5: Determine whether the current operating mode of the system is fully automatic or semi-automatic. If the current operating mode of the system is fully automatic, after obtaining the exit water storage cooling mode flag signal, the system control program will first open the cooling tower with the shortest running time and the corresponding valve, and then open the cooling pump with the shortest running time and the corresponding valve (if the computer room system structure is one machine to one pump, the cooling pump and valve corresponding to the host with the smallest capacity and no faults will be opened). When the cooling pump and cooling tower are both in operation, the host with the smallest capacity and no faults will be opened for cooling. If the current operating mode of the system is semi-automatic, after obtaining the exit water storage cooling mode flag signal, the system control program will first open the cooling tower with the shortest running time and the corresponding valve, and then open the cooling pump with the shortest running time and the corresponding valve (if the computer room system structure is one machine to one pump, the cooling pump and valve corresponding to the host selected in the semi-automatic mode will be opened). When the cooling pump and cooling tower are both in operation, when the cooling pump and cooling tower are both in operation, the host selected in the semi-automatic mode will be opened for cooling.

[0132] This embodiment has the following technical effects:

[0133] 1. A method for controlling the operation of an air-conditioning system under low-load conditions is proposed. The method controls the start and stop of the air-conditioning system equipment according to the change of the refrigerated return water temperature of the air-conditioning system, thereby reducing the phenomenon of frequent start and stop of the host. At the same time, it can also reduce the energy consumption of the air-conditioning system and achieve a more energy-saving effect.

[0134] 2. A method for optimizing the setting parameters of an air-conditioning system when the air-conditioning system is in a low-load condition is proposed. This method can automatically optimize and update the parameters of the water storage cooling model according to the current operating status of the air-conditioning system, so that the air-conditioning system can maintain a more efficient operating state.

[0135] 3. This control method is fully automatic control. It can run fully automatically after only setting the operating parameters, without manual switching of the equipment.

[0136] 4. This control method can control the system host downtime by adjusting the set value, so that the system host can reach a more ideal intermittent operation state.

[0137] Example 2

[0138] like Figure 4 Schematic diagram of water storage cooling mode parameter optimization.

[0139] The entry mode temperature T set for this water storage cooling mode 1,k and the host target water outlet temperature setting value T s,k , determine whether the system can enter the water storage cooling mode according to the actual operating status of the host, the following situations exist:

[0140] If the water storage cooling mode can be entered and the duration of the water storage cooling mode is longer than the set time t s Subtract the dead zone t d , the parameters of the water storage cooling mode remain at the original values ​​and no optimization operation is performed. s and dead zone t d Set according to the operating conditions.

[0141] If the air conditioning system can enter the water storage cooling mode but the time it enters the water storage cooling mode is less than the set time t s Reduce dead zone t d , it means that the air conditioning system enters the water storage cooling mode for too short a time, and the host will start and stop too frequently. In this case, the entry mode temperature T1 set for entering the water storage cooling mode is optimized according to the chilled water return temperature optimization model.

[0142] If the air conditioning system cannot enter the water storage cooling mode under the current parameters, the current host target water outlet temperature setting value T of the air conditioning host is set. s,k The entry mode temperature T set for this water storage cooling mode 1,k Adjustment is made so that the air conditioning system can enter the water storage cooling mode; further determining the adjusted entry mode temperature T 1,k Whether the actual time of entering the water storage cooling meets the set time, if so, the adjusted entry mode temperature T 1,k Updated to the entry mode temperature T1; if the adjusted entry mode temperature T 1,k If the actual water storage time does not meet the set time, the adjusted entry mode temperature T is adjusted according to the chilled water return temperature optimization model. 1,k Optimize; get the optimized T 1,k After obtaining the updated entry mode temperature T1, the host target water outlet temperature setting value T s Make optimizations.

[0143] After completing the water storage mode setting temperature T1 and the host target water outlet temperature setting value T s After optimization, the air conditioning system will be in a relatively ideal intermittent start-stop operation state, which can meet the set value of the single water storage duration, and there will be no frequent start-stop of the host or the system cannot enter the water storage mode. This intermittent host operation state has a higher energy efficiency value than the original frequent start-stop and long-term low-load rate operation of the host, and can achieve the effect of energy saving and consumption reduction.

[0144] Example 3

[0145] To achieve the above-mentioned purpose, the present embodiment provides a control device for an air-conditioning system, the device comprising: a memory 710 and a processor 720; the memory is used to store a program for controlling the air-conditioning system, and the processor is used to read and execute the program for controlling the air-conditioning system, and execute any of the methods in the above-mentioned embodiments.

[0146] Example 4

[0147] Taking a building that still needs low-load cooling in winter as an example, we took data with similar cooling capacity of the main engine on that day to analyze the start-stop times and energy saving rate of the main engine in the normal operation mode and water storage cooling operation mode of the building's air-conditioning system. The building has a low cooling load demand in winter, and the main engine still starts and stops frequently when it runs at the lower load rate. Figure 6The figure shows the daily start and stop times of the main engine in the conventional operation mode and the water storage cooling operation mode of a certain building. It can be seen from the figure that under similar cooling load conditions, the water storage cooling operation mode can effectively reduce the start and stop times of the main engine, and compared with the original operation mode, the comprehensive energy saving rate of the water storage cooling operation mode exceeds 20%.

[0148] The beneficial effect of the present application is that it proposes an operation optimization control method for the air-conditioning system under low-load conditions, which can fully automatically control the start and stop of the air-conditioning system equipment according to the change of the refrigerated return water temperature of the air-conditioning system, so as to extend the downtime of the host and reduce the number of start and stop times of the host, and at the same time reduce the loss of equipment service life caused by frequent start and stop of the host. The control method can automatically shut down the system cooling pump and cooling tower when the host is shut down, reduce the power consumption of the system, improve the energy efficiency of the air-conditioning system, and achieve a more energy-saving effect.

[0149] It will be appreciated by those skilled in the art that all or some of the steps, systems, and functional modules / units in the methods disclosed above may be implemented as software, firmware, hardware, and appropriate combinations thereof. In hardware implementations, the division between the functional modules / units mentioned in the above description does not necessarily correspond to the division of physical components; for example, a physical component may have multiple functions, or a function or step may be performed by several physical components in cooperation. Some or all components may be implemented as software executed by a processor, such as a digital signal processor or a microprocessor, or implemented as hardware, or implemented as an integrated circuit, such as an application-specific integrated circuit. Such software may be distributed on a computer-readable medium, which may include a computer storage medium (or non-transitory medium) and a communication medium (or temporary medium). As known to those skilled in the art, the term computer storage medium includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information (such as computer-readable instructions, data structures, program modules, or other data). Computer storage media include, but are not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tapes, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store the desired information and can be accessed by a computer. In addition, it is well known to those of ordinary skill in the art that communication media typically contain computer-readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave or other transport mechanism, and may include any information delivery media.

Claims

1. A control method for an air conditioning system, characterized in that: The method comprises: Determining that the air conditioning system meets the set entry conditions of the water storage cooling mode, and controlling the air conditioning system to enter the water storage cooling mode, wherein the entry conditions include that the air conditioning system is in a low-load operation state, and the chilled water return temperature is less than the set entry mode temperature; Determining that the air conditioning system meets a set exit condition of the water storage cooling mode, and controlling the air conditioning system to exit the water storage cooling mode, wherein the exit condition includes that the chilled water return temperature is greater than a set exit mode temperature; Wherein, the set entry mode temperature is lower than the set exit mode temperature; After controlling the air conditioning system to enter the water storage cooling mode, the method further includes: recording the operation time of the air conditioning system in the water storage cooling mode this time, and when the operation time does not meet the set time requirement, determining an entry mode temperature that can meet the time requirement, and updating the set entry mode temperature to the entry mode temperature that can meet the time requirement; The step of determining the entry mode temperature that can meet the duration requirement includes: According to the set duration in the water storage cooling mode, the entry mode temperature and the exit mode temperature when entering the water storage cooling mode this time, determine the entry mode temperature that can meet the duration requirement; The step of determining that the air conditioning system is in a low-load operation state comprises: In the fully automatic mode, when the number of currently running hosts is 1, the currently running host is the host with the smallest capacity among the hosts without faults, and the host load rate is lower than the set minimum load rate, it is determined that the air conditioning system is in a low-load operation state; In the semi-automatic mode, when the current number of host machines in operation is 1 and the host load rate is lower than the set minimum load rate, it is determined that the air-conditioning system is in a low-load operation state.

2. The control method of the air conditioning system according to claim 1, characterized in that: Determining the entry mode temperature that can meet the duration requirement according to the set duration in the water storage cooling mode, the entry mode temperature when entering the water storage cooling mode this time, and the exit mode temperature includes: According to the set duration in the water storage cooling mode, the entry mode temperature and the exit mode temperature when entering the water storage cooling mode, the chilled water return temperature optimization model is used to determine the entry mode temperature that can meet the duration requirements; Among them, the optimization model of the chilled water return temperature is: Where, t s is the duration of the water storage cooling mode, t k is the operation time in the water storage cooling mode, a is the fitting coefficient, T 1,k is the entry mode temperature when entering the water storage cooling mode, T 1,s T2 is the entry mode temperature that meets the duration requirement, and T3 is the exit mode temperature.

3. The control method of the air conditioning system according to claim 1, characterized in that: The method further includes: when the air-conditioning system is in a low-load operation state and the air-conditioning system does not enter the water storage cooling mode within the maximum allowed waiting time, increasing the set entry mode temperature so that the air-conditioning system can enter the water storage cooling mode.

4. The control method of the air conditioning system according to claim 3, characterized in that: The step of increasing the set entry mode temperature includes: The target outlet water temperature setting value of the host at the current moment is calculated according to the temperature increase model to obtain the set entry mode temperature after the increase; updating the increased set entry mode temperature as the entry mode temperature; Among them, the temperature increase model is: Where, T 1,k is the entry mode temperature set this time, T s,k is the target outlet water temperature setting value of the host at the current moment, and d is a constant.

5. The control method of the air conditioning system according to claim 2, characterized in that: After raising the set entry mode temperature so that the air-conditioning system enters the water storage cooling mode, the method also includes: recording the operating time of the air-conditioning system in the water storage cooling mode, and when the operating time does not meet the set time requirement, determining the entry mode temperature that can meet the time requirement, updating the set entry mode temperature to the entry mode temperature that can meet the time requirement, and lowering the host target water outlet temperature setting value.

6. The control method of the air conditioning system according to claim 5, characterized in that: The step of lowering the target outlet water temperature setting value of the host comprises: According to the entry mode temperature that meets the time requirement, the host target water outlet temperature setting value at the current moment, and the entry mode temperature set this time, the host target water outlet temperature setting value after the adjustment is obtained by adjusting the model; Among them, the lowering model is: Where, T s,k+1 is the lowered target outlet water temperature setting value of the host, T s,k is the target outlet water temperature setting value of the host at the current moment, T 1,k is the entry mode temperature set this time, T 1,s To meet the entry mode temperature required for the duration, b is the first setting coefficient and c is the second setting coefficient.

7. A control device for an air conditioning system, the device comprising: A memory and a processor; characterized in that the memory is used to store a program for controlling an air-conditioning system, and the processor is used to read and execute the program for controlling the air-conditioning system, and execute the method described in any one of claims 1-6.

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