Water temperature control method, device, control equipment and air conditioning system

Abstract

The present invention relates to a water temperature control method, device, control equipment and air conditioning system, the water temperature control method comprising: obtaining a target adjustment method for the number of operating units in the air conditioning system and the actual load rate of the operating units; determining the reserved load rate of the operating units in the air conditioning system based on the target adjustment method, the reserved load rate is determined according to the load required to eliminate the water temperature fluctuation caused by adjusting the number of operating units; if the actual load rate is less than or equal to the reserved load rate, reducing the outlet water temperature of the operating unit; after the outlet water temperature of the operating unit is reduced, adjusting the number of operating units according to the target adjustment method, and adjusting the main pipe water supply temperature of the air conditioning system to a preset temperature range based on the target adjustment method. The present application can eliminate the water temperature fluctuation caused by the adjustment of the number of operating units, improve the water temperature control accuracy, achieve dual optimization of system performance and production efficiency, ensure the temperature control requirements of the production process, and thus improve production efficiency and product yield.

Description

Technical Field

[0001] The present application relates to the field of air conditioning technology, and in particular to a water temperature control method, device, control equipment and air conditioning system. Background Art

[0002] In modern large-scale factories, especially in process manufacturing and precision air handling systems, a stable supply of chilled water is essential. These systems usually involve temperature control of sensitive equipment or products, so temperature fluctuations may have a negative impact on product quality or production processes. In order to meet this demand, factories usually use multiple air conditioning systems in parallel to provide chilled water. The advantage of this configuration is its flexibility and redundancy. Even if a chiller fails, other chillers can continue to operate to ensure the stability of the system.

[0003] However, in actual applications, fluctuations in load demand pose challenges to this configuration, especially when the air-conditioning system adds or subtracts machine operations according to load changes. The start or stop of the air-conditioning system will cause temperature changes inside the chilled water system and the water temperature is difficult to stabilize immediately, which in turn affects the temperature control requirements of the production process. Summary of the invention

[0004] In order to solve the technical problem that when the air-conditioning system is adding and subtracting machines, the temperature inside the chilled water system changes and the water temperature is difficult to stabilize immediately, the present application provides a water temperature control method, device, control equipment and air-conditioning system.

[0005] In a first aspect, the present application provides a water temperature control method, comprising:

[0006] Obtaining a target adjustment method for the number of operating units in the air-conditioning system and an actual load rate of the operating units;

[0007] Determining a reserved load rate of the operating units in the air-conditioning system based on the target adjustment method, wherein the reserved load rate is determined according to the load required to eliminate water temperature fluctuations caused by adjusting the number of operating units;

[0008] If the actual load rate is less than or equal to the reserved load rate, lowering the outlet water temperature of the operating unit;

[0009] After the outlet water temperature of the operating units is reduced, the number of the operating units is adjusted according to the target adjustment method, and the main pipe water supply temperature of the air-conditioning system is adjusted to a preset temperature range based on the target adjustment method.

[0010] Optionally, determining a reserved load rate of an operating unit in the air-conditioning system based on the target adjustment mode includes:

[0011] Obtaining minimum load calculation parameters corresponding to the target adjustment method;

[0012] Calculate the minimum operating load of the unit to be adjusted according to the minimum load calculation parameters;

[0013] Obtaining the total rated cooling capacity of the operating units in the air-conditioning system;

[0014] The reserved load rate is calculated according to the minimum operating load and the sum of the rated cooling capacities.

[0015] Optionally, obtaining a minimum load calculation parameter corresponding to the target adjustment method includes:

[0016] If the target adjustment method is to add a chiller to the air-conditioning system, the minimum water flow rate of the first chiller to be added, the water temperature of the water supply loop of the first chiller and the upper limit of the main water supply temperature are obtained as the minimum load calculation parameters;

[0017] or,

[0018] If the target adjustment method is to reduce the number of chillers in the air-conditioning system, the current operating water flow of the second chiller to be reduced, the water temperature of the water supply loop of the second chiller and the upper limit of the main water supply temperature are obtained as the minimum load calculation parameters;

[0019] Calculating the minimum operating load of the unit to be adjusted according to the minimum load calculation parameters includes:

[0020] Calculating the minimum operating load of the first chiller according to the minimum water flow of the first chiller, the water temperature of the water supply loop of the first chiller and the upper limit of the main pipe water supply temperature;

[0021] or,

[0022] The minimum operating load of the second chiller is calculated based on the current operating water flow of the second chiller, the water temperature of the water supply loop of the second chiller and the upper limit of the main pipe water supply temperature.

[0023] Optionally, adjusting the number of the operating units according to the target adjustment method includes:

[0024] If the target adjustment method is to add a chiller to the air-conditioning system, control the first chiller to be added to the air-conditioning system to start, and control the chilled water pump of the first chiller to operate at a minimum frequency;

[0025] or,

[0026] If the target adjustment method is to reduce the number of chillers in the air-conditioning system, the second chiller to be reduced from the air-conditioning system is controlled to be turned off.

[0027] Optionally, adjusting the main pipe water supply temperature of the air conditioning system to a preset temperature range based on the target adjustment method includes:

[0028] Get the current main water supply temperature;

[0029] Determine whether the current main pipe water supply temperature is less than the main pipe water supply temperature upper limit value;

[0030] If the current main pipe water supply temperature is less than the main pipe water supply temperature upper limit value, determine whether the adjusted unit has reached the primary adjustment target based on the target adjustment method, and if the adjusted unit has reached the primary adjustment target, adjust the water supply temperature of the operating unit of the air-conditioning system to the initial setting value of the water supply temperature of the operating unit;

[0031] If the current main water supply temperature is greater than or equal to the main water supply temperature upper limit, the water supply temperature of the operating units of the air-conditioning system is adjusted to the main water supply temperature lower limit, and after a preset time period, the step of determining whether the current main water supply temperature is less than the main water supply temperature upper limit is re-executed.

[0032] Optionally, determining whether the adjusted unit reaches the primary adjustment target based on the target adjustment method includes:

[0033] Determine whether the water temperature of the water supply loop of the first chiller of the air-conditioning system is less than the upper limit of the water supply temperature of the main pipe; if the water temperature of the water supply loop is less than the upper limit of the water supply temperature of the main pipe, determine that the first chiller reaches the primary adjustment target;

[0034] or,

[0035] Determine whether the refrigeration side loop valve opening of the second chiller that has been removed from the air-conditioning system is 0; if the refrigeration side loop valve opening of the second chiller is 0, determine that the second chiller reaches the primary adjustment target.

[0036] Optionally, the method further comprises:

[0037] If an adjustment instruction for the number of operating units in the air conditioning system is received, determining whether the current main pipe water supply temperature is greater than the main pipe water supply temperature upper limit value;

[0038] If the current main pipe water supply temperature is greater than the main pipe water supply temperature upper limit value, the step of obtaining a target adjustment method for the number of operating units in the air-conditioning system and an actual load rate of the operating units is executed.

[0039] In a second aspect, the present application provides a water temperature control device, comprising:

[0040] An acquisition module, used to acquire a target adjustment method for the number of operating units in the air-conditioning system and an actual load rate of the operating units;

[0041] A determination module, configured to determine a reserved load rate of the operating units in the air-conditioning system based on the target adjustment method, wherein the reserved load rate is determined according to a load required to eliminate water temperature fluctuations caused by adjusting the number of operating units;

[0042] A reduction module, used for reducing the outlet water temperature of the operating unit if the actual load rate is less than or equal to the reserved load rate;

[0043] The adjustment module is used to adjust the number of the operating units according to the target adjustment method after the outlet water temperature of the operating units is reduced, and adjust the main pipe water supply temperature of the air-conditioning system to a preset temperature range based on the target adjustment method.

[0044] In a third aspect, the present application provides a control device, including a processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory communicate with each other via the communication bus;

[0045] Memory, used to store computer programs;

[0046] The processor is used to implement any water temperature control method described in the first aspect when executing the program stored in the memory.

[0047] In a fourth aspect, the present application provides an air-conditioning system, comprising the control device as described in the third aspect.

[0048] The above technical solution provided by the embodiment of the present application has the following advantages compared with the prior art:

[0049] The present application reserves a load for lowering the water temperature through conditional judgment of the reserved load rate, so that the operating units can have sufficient load to lower the outlet water temperature. After lowering the outlet water temperature of the operating units, the number of operating units is adjusted to reduce the water temperature fluctuation caused by the adjustment of the number of operating units. Then, by adjusting the main water supply temperature of the air-conditioning system to a preset temperature range, the water temperature fluctuation caused by the adjustment of the number of operating units is further eliminated, the water temperature control accuracy is improved, and the dual optimization of system performance and production efficiency is achieved, ensuring the temperature control requirements of the production process, thereby improving production efficiency and product yield. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0051] In order to more clearly illustrate the embodiments of the present invention 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, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0052] Figure 1 A flow chart of a water temperature control method provided in an embodiment of the present application;

[0053] Figure 2 A flow chart of a water temperature control method in a practical application provided by an embodiment of the present application;

[0054] Figure 3 A structural diagram of an air conditioning system provided in an embodiment of the present application;

[0055] Figure 4 A structural diagram of a water temperature control device provided in an embodiment of the present application;

[0056] Figure 5 A structural diagram of a control device provided in an embodiment of the present application.

[0057] 1. Chiller; 2. Evaporator; 3. Condenser; 4. Chilled water pump; 5. Temperature sensor; 6. Cooling water pump; 7. Cooling tower. DETAILED DESCRIPTION

[0058] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are 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 making creative work are within the scope of protection of this application.

[0059] In the current industry context, with the increasing requirements for industrial automation and refined manufacturing, the production process has become more stringent in terms of temperature control requirements. Especially in the fields of semiconductors, pharmaceuticals, biotechnology, etc., the accuracy of temperature control is directly related to product quality and production efficiency. Therefore, how to stably provide cold water at the target temperature when the load demand fluctuates has become an important issue in the industry. Although the traditional parallel connection of multiple chillers provides flexibility, how to effectively avoid temperature fluctuations caused by the operation of the adder and subtractor during load fluctuations is still a problem that needs to be solved. To this end, the industry is seeking more advanced control strategies or system configurations to meet this challenge. In order to effectively avoid water temperature fluctuations caused by the operation of the adder and subtractor during load fluctuations, the embodiments of the present application provide a water temperature control method, device, control equipment and air-conditioning system.

[0060] The present application provides a water temperature control method, which can be applied to cold water system, hot water system, multi-split system and other system forms, or multi-head unit system, such as Figure 1 As shown, the water temperature control method may include the following steps:

[0061] Step S101, obtaining a target adjustment method for the number of operating units in the air-conditioning system and an actual load rate of the operating units;

[0062] In an embodiment of the present application, the target adjustment method can be to add a chiller to the air-conditioning system, that is, to add a chiller to the air-conditioning system, or it can be to reduce the chiller to the air-conditioning system, that is, to reduce the chiller in the air-conditioning system. The target adjustment method can be determined based on the information carried by the received adjustment instruction. The adjustment instruction can be an adjustment instruction for instructing to add a running unit to the air-conditioning system, or it can be an adjustment instruction for instructing to reduce a running unit of the air-conditioning system.

[0063] The operating unit in the air-conditioning system may refer to one or more chillers in operation in the air-conditioning system. The actual load rate of the operating unit in the air-conditioning system refers to the ratio between the load borne by the operating unit and its maximum design load during the actual operation of the air-conditioning system, which can be obtained by calculation.

[0064] Before step S101, the method further includes:

[0065] If an adjustment instruction for the number of operating units in the air-conditioning system is received, determine whether the current main pipe water supply temperature is greater than the main pipe water supply temperature upper limit; wherein the main pipe water supply temperature can be detected by a temperature sensor arranged on the main pipe of the air-conditioning system.

[0066] If the current main pipe water supply temperature is greater than the main pipe water supply temperature upper limit value, the step of obtaining a target adjustment method for the number of operating units in the air-conditioning system and an actual load rate of the operating units is executed.

[0067] After receiving the adjustment instruction, the target adjustment method can be determined according to the information carried by the adjustment instruction. Moreover, after receiving the adjustment instruction, it can be further determined whether the current main water supply temperature of the air-conditioning system is greater than the upper limit value of the main water supply temperature. If the current main water supply temperature of the air-conditioning system is greater than the upper limit value of the main water supply temperature, it indicates that the current main water supply temperature exceeds the limit and water temperature control is required, and step S101 can be executed.

[0068] Step S102, determining a reserved load rate of the operating units in the air-conditioning system based on the target adjustment method, wherein the reserved load rate is determined according to the load required to eliminate the water temperature fluctuation caused by adjusting the number of operating units. Further, the reserved load rate is 1 minus the ratio of the load required to eliminate the water temperature fluctuation caused by adjusting the number of operating units to the maximum design load of the operating units. For details, please refer to the following embodiments;

[0069] In order to ensure that the running units can eliminate the water temperature fluctuations caused by adjusting the number of running units when adding or subtracting machines, in this step, the reserved load rate of the running units in the air-conditioning system can be obtained. Due to different target adjustment methods, the methods of calculating the reserved load rate are different. Therefore, the reserved load rate of the running units in the air-conditioning system can be determined based on the target adjustment method.

[0070] Step S103, if the actual load rate is less than or equal to the reserved load rate, lowering the outlet water temperature of the operating unit;

[0071] When the operating unit includes one chiller, the outlet water temperature of the chiller is the outlet water temperature of the operating unit. When the operating unit includes multiple chillers, the average of the outlet water temperatures of the multiple chillers is the outlet water temperature of the operating unit.

[0072] If the actual load rate of the operating units is less than or equal to the reserved load rate, it indicates that the remaining load rate of the operating units can eliminate the water temperature fluctuation caused by adjusting the number of operating units, and water temperature control can continue, that is, the outlet water temperature of the operating units can be lowered. Since adding or reducing units will cause the water temperature of the water supply circuit to rise, in order to reduce water temperature fluctuations, the outlet water temperature of the operating units can be lowered first, so that the outlet water temperature of the operating units is closer to the water temperature change caused by adding or reducing units, thereby reducing water temperature fluctuations.

[0073] In one implementation of the present application, the outlet water temperature of the operating unit can be reduced to the lower limit of the main pipe water supply temperature.

[0074] Step S104, after the outlet water temperature of the operating units is reduced, the number of the operating units is adjusted according to the target adjustment method, and the main pipe water supply temperature of the air-conditioning system is adjusted to a preset temperature range based on the target adjustment method.

[0075] In one embodiment of the present application, if the target adjustment method is to add a chiller to the air-conditioning system, the first chiller to be added to the air-conditioning system is controlled to be turned on, and the chilled water pump of the first chiller is controlled to operate at a minimum frequency;

[0076] In another embodiment of the present application, if the target adjustment method is to reduce the number of chillers in the air-conditioning system, the second chiller to be reduced from the air-conditioning system is controlled to be shut down.

[0077] In the embodiment of the present application, the preset temperature interval may refer to a temperature interval formed by an upper limit value of the main pipe water supply temperature and a lower limit value of the main pipe water supply temperature.

[0078] When adjusting the main water supply temperature of the air-conditioning system to a preset temperature range, different primary adjustment targets can be set for different target adjustment methods. After the primary adjustment target is completed, the main water supply temperature is finally adjusted to the preset temperature range, and the adjustment of the main water supply temperature is gradually completed to improve the success rate of the main water supply temperature adjustment.

[0079] The present application reserves a load for lowering the water temperature through conditional judgment of the reserved load rate, so that the operating units can have sufficient load to lower the outlet water temperature. After lowering the outlet water temperature of the operating units, the number of operating units is adjusted to reduce the water temperature fluctuation caused by the adjustment of the number of operating units. Then, by adjusting the main water supply temperature of the air-conditioning system to a preset temperature range, the water temperature fluctuation caused by the adjustment of the number of operating units is further eliminated, the water temperature control accuracy is improved, and the dual optimization of system performance and production efficiency is achieved, ensuring the temperature control requirements of the production process, thereby improving production efficiency and product yield.

[0080] In another embodiment of the present application, step S102 determines the reserved load rate of the operating units in the air-conditioning system based on the target adjustment method, including:

[0081] Step S201, obtaining minimum load calculation parameters corresponding to the target adjustment method;

[0082] In one embodiment of the present application, if the target adjustment method is to add a chiller to the air-conditioning system, the minimum water flow rate of the first chiller to be added, the water temperature of the water supply loop of the first chiller and the upper limit of the main pipe water supply temperature are obtained as the minimum load calculation parameters;

[0083] In another embodiment of the present application, if the target adjustment method is to reduce the number of chillers in the air-conditioning system, the current operating water flow of the second chiller to be reduced, the water temperature of the water supply loop of the second chiller and the upper limit of the main water supply temperature are obtained as the minimum load calculation parameters.

[0084] Step S202, calculating the minimum operating load of the unit to be adjusted according to the minimum load calculation parameters;

[0085] In one embodiment of the present application, the minimum operating load of the first chiller is calculated according to the minimum water flow of the first chiller, the water temperature of the water supply loop of the first chiller, and the upper limit of the main pipe water supply temperature; the minimum operating load Qmin of the first chiller can be calculated according to the following formula:

[0086] Qmin= C* Min* (Tdg-Tgmax)

[0087] Wherein, C is the specific heat capacity, Min is the minimum water flow rate of the first chiller, Tdg is the water temperature of the water supply loop of the first chiller, and Tgmax is the upper limit of the main pipe water supply temperature.

[0088] In another embodiment of the present application, the minimum operating load of the second chiller is calculated according to the current operating water flow of the second chiller, the water temperature of the water supply loop of the second chiller and the upper limit of the main pipe water supply temperature; the minimum operating load Qmin of the second chiller can be calculated according to the following formula:

[0089] Qmin= C*Mj*(Tgmax-Tdg)

[0090] Wherein, C is the specific heat capacity, Mj is the current operating water flow of the second chiller, Tdg is the water temperature of the water supply loop of the second chiller, and Tgmax is the upper limit of the main pipe water supply temperature.

[0091] Step S203, obtaining the total rated cooling capacity of the operating units in the air-conditioning system;

[0092] The rated cooling capacity of the air-conditioning system is calculated based on the equipment specifications and specific design parameters. This is existing technology and will not be described in detail here.

[0093] Step S204: Calculate the reserved load rate according to the minimum operating load and the total rated cooling capacity.

[0094] In the embodiment of the present application, the reserved load rate Xy can be calculated according to the following formula:

[0095] Xy=1-Qmin / Qz

[0096] Among them, Qz is the total rated cooling capacity and Qmin is the minimum operating load.

[0097] The embodiment of the present application can calculate the reserved load rate so as to reserve load for lowering the water temperature through conditional judgment of the reserved load rate, so that the operating unit can have sufficient load to lower the outlet water temperature.

[0098] In another embodiment of the present application, step S104 adjusts the main pipe water supply temperature of the air conditioning system to a preset temperature range based on the target adjustment method, including:

[0099] Step S301, obtaining the current main water supply temperature;

[0100] Since step S104 is performed after the number of operating units is adjusted, the main pipe water supply temperature will change compared to before the adjustment, so the current main pipe water supply temperature after the number of operating units is adjusted is obtained.

[0101] Step S302, determining whether the current main pipe water supply temperature is less than the main pipe water supply temperature upper limit;

[0102] Step S303, if the current main pipe water supply temperature is less than the main pipe water supply temperature upper limit value, determine whether the adjusted unit has reached the primary adjustment target based on the target adjustment method, and if the adjusted unit has reached the primary adjustment target, adjust the water supply temperature of the operating unit of the air-conditioning system to the initial setting value of the water supply temperature of the operating unit;

[0103] In one embodiment of the present application, determining whether the adjusted unit has reached the primary adjustment target based on the target adjustment method includes: determining whether the water temperature of the water supply loop of the first chiller added to the air-conditioning system is less than the upper limit of the main pipe water supply temperature; if the water temperature of the water supply loop is less than the upper limit of the main pipe water supply temperature, determining that the first chiller has reached the primary adjustment target;

[0104] In another embodiment of the present application, determining whether the adjusted unit has reached the primary adjustment target based on the target adjustment method includes: determining whether the opening of the refrigeration side loop valve of the second chiller that has been reduced from the air-conditioning system is 0; if the opening of the refrigeration side loop valve of the second chiller is 0, determining that the second chiller has reached the primary adjustment target. The present application can combine water pump and valve control at the same time to improve the stability of water supply temperature.

[0105] Step S304, if the current main water supply temperature is greater than or equal to the main water supply temperature upper limit value, adjust the water supply temperature of the operating units of the air-conditioning system to the main water supply temperature lower limit value, and re-execute the step of determining whether the current main water supply temperature is less than the main water supply temperature upper limit value after a preset time period.

[0106] The embodiment of the present application can automatically adjust the main water supply temperature to a preset temperature range, further eliminate water temperature fluctuations caused by adjustments to the number of operating units, and improve water temperature control accuracy.

[0107] For ease of understanding, Figure 2 As shown, the present application also provides an embodiment of adding a machine to an air conditioning system in a practical application.

[0108] Step 1: Read system parameters: number of units in operation, unit load rate, unit return water temperature, operating unit supply water temperature setting value, main pipe supply water temperature, main pipe supply water temperature setting value, minimum water flow of the first chiller to be added, and water temperature of the water supply loop of the unit to be added;

[0109] Step 2: Input the upper limit value Tgmax and lower limit value Tgmin of the main water supply temperature;

[0110] Step 3: When adding a unit, determine whether the main pipe water supply temperature Tg> the main pipe water supply temperature upper limit Tgmax? If yes, proceed to step 4, otherwise, do not start the water temperature control mode;

[0111] Step 4: Turn on the water temperature control mode;

[0112] Step 5: Calculate the minimum load Qmin of the machine according to Min, Tdg and Tgmax;

[0113] Among them, Qmin=C*Minimum water flow rate of the first chiller Min*(water temperature of the water supply loop of the standby unit Tdg-upper limit value of the main pipe water supply temperature Tgmax);

[0114] Among them, C is the specific heat capacity; Min is the minimum water flow of the first chiller, which can be obtained from the unit model information; Tdg is the water temperature of the water supply loop of the standby unit; Tgmax is the upper limit of the main pipe water supply temperature;

[0115] Step 6: Calculate and update the reserved load rate Xy of the operating unit in real time;

[0116] Among them, the unit reserved load rate Xy = 1-the minimum load of the additional unit Qmin / the total rated cooling capacity of all running units Qz;

[0117] Among them, Qz is the sum of the rated cooling capacity of all running units; Qmin is the minimum load of the added unit;

[0118] Step 7: Determine whether the actual load rate of the running unit X ≤ the reserved load rate of the running unit Xy-ΔX? If yes, proceed to step 8, otherwise return to step 6;

[0119] Among them, X is the actual load rate of the operating unit; Xy is the reserved load rate of the operating unit; ΔX is the reserved deviation value, which is selected according to the actual project situation, and the default value is 5%;

[0120] Step 8: Record the initial set value Tygx of the running unit water supply temperature after the change as the initial set value Tygx0 of the running unit water supply temperature, and set Tygx=the lower limit value Tgmin of the main pipe water supply temperature;

[0121] Among them, Tygx0 is the initial setting value of the water supply temperature of the running unit; Tygx is the setting value after the water supply temperature of the running unit is changed; Tgmin is the lower limit of the main pipe water supply temperature;

[0122] Step 9: Start the units to be operated, and the corresponding chilled water pumps run at the minimum frequency;

[0123] Step 10: Determine whether the main pipe water supply temperature Tg is less than the upper limit value of the main pipe water supply temperature Tgmax-ΔT? If yes, proceed to step 12; otherwise, proceed to step 11;

[0124] Among them, Tg is the main pipe water supply temperature; Tgmax is the upper limit of the main pipe water supply temperature; ΔT is the water temperature deviation value, which is selected according to the actual project situation, and the default value is 0.5℃;

[0125] Step 11: Set the water supply temperature setting value Tygx of the running unit to the lower limit value of the main water supply temperature Tgmin - ΔTz. After the interval t, re-judge step 10;

[0126] Among them, Tygx is the set value of the water supply temperature of the operating unit, Tgmin is the lower limit of the main pipe water supply temperature; ΔTz is the temperature increment, which is selected according to the actual project situation, and the default value is 0.5℃;

[0127] Step 12: Determine whether the water temperature of the water supply loop of the machine to be added Tdg is less than the upper limit value of the water supply temperature of the main pipe Tgmax. If yes, proceed to step 13; otherwise, after an interval of time t, re-determine step 12;

[0128] Among them, Tdg is the water temperature of the water supply loop of the waiting machine; Tgmax is the upper limit of the main pipe water supply temperature; the time t is selected according to the actual project situation, and the default value is 2min;

[0129] Step 13: Set the water supply temperature setting value Tygx of the running unit to the initial setting value Tygx0 of the water supply temperature of the running unit, and the refrigeration pump of the unit to be run is controlled by the original group control system;

[0130] Among them, Tygx is the set value of the water supply temperature of the running unit, and Tygx0 is the initial set value of the water supply temperature of the running unit; the group control system generally controls the refrigeration pump by fixed supply and return water temperature difference or pressure difference control, and adopts PID regulation;

[0131] Step 14: When adding the machine again, the water temperature control mode is turned on by default and go to step 5.

[0132] For ease of understanding, the present application also provides an embodiment of reducing the number of machines in an air conditioning system in a practical application.

[0133] Step 1: Read system parameters: number of units in operation, unit load rate, unit return water temperature, operating unit supply water temperature setting value, main pipe supply water temperature, main pipe supply water temperature setting value, current operating water flow of the second chiller of the unit to be reduced, and valve opening of the refrigeration side loop of the unit to be reduced;

[0134] Step 2: Input the upper limit value Tgmax and lower limit value Tgmin of the main water supply temperature;

[0135] Step 3: When the unit is reduced, determine whether the main pipe water supply temperature Tg> the main pipe water supply temperature upper limit Tgmax? If yes, go to step 4, otherwise, do not start the water temperature control mode;

[0136] Step 4: Turn on the water temperature control mode;

[0137] Step 5: According to Min, Tdg, and Tgmax, the computer group runs the minimum load Qmin;

[0138] Wherein, Qmin=C*current operating water flow rate of the second chiller Mj*(upper limit value of main water supply temperature Tgmax-water temperature of the water supply loop of the second chiller Tdg);

[0139] Among them, C is the specific heat capacity; Mj is the current operating water flow of the standby reducer unit; Tdg is the water temperature of the water supply loop of the standby reducer unit; Tgmax is the upper limit of the main pipe water supply temperature;

[0140] Step 6: Calculate and update the reserved load rate Xy of the operating unit in real time;

[0141] Among them, the unit reserved load rate Xy = 1-the minimum operating load of the unit Qmin / the total rated cooling capacity of the operating unit after the reduction of the unit Qz;

[0142] Among them, Qz is the sum of the rated cooling capacity of all running units; Qmin is the minimum operating load of the unit;

[0143] Step 7: Determine whether the actual load rate of the running unit X ≤ the reserved load rate of the running unit Xy-ΔX? If yes, proceed to step 8, otherwise return to step 6;

[0144] Among them, X is the actual load rate of the operating unit; Xy is the reserved load rate of the operating unit; ΔX is the reserved deviation value, which is selected according to the actual project situation, and the default value is 5%;

[0145] Step 8: Record the initial set value Tygx of the running unit water supply temperature after the change as the initial set value Tygx0 of the running unit water supply temperature, and set Tygx=the lower limit value Tgmin of the main pipe water supply temperature;

[0146] Among them, Tygx0 is the initial setting value of the water supply temperature of the running unit; Tygx is the setting value after the water supply temperature of the running unit is changed; Tgmin is the lower limit of the main pipe water supply temperature;

[0147] Step 9: Control the second chiller to be removed from the air-conditioning system to shut down and the pump and valve of the corresponding water circuit;

[0148] Step 10: Determine whether the main pipe water supply temperature Tg is less than the upper limit value of the main pipe water supply temperature Tgmax-ΔT? If yes, proceed to step 12; otherwise, proceed to step 11;

[0149] Among them, Tg is the main pipe water supply temperature; Tgmax is the upper limit of the main pipe water supply temperature; ΔT is the water temperature deviation value, which is selected according to the actual project situation, and the default value is 0.5℃;

[0150] Step 11: Set the water supply temperature setting value Tygx of the running unit to the lower limit value of the main water supply temperature Tgmin - ΔTz. After the interval t, re-judge step 10;

[0151] Among them, Tygx is the set value of the water supply temperature of the operating unit, Tgmin is the lower limit of the main pipe water supply temperature; ΔTz is the temperature increment, which is selected according to the actual project situation, and the default value is 0.5℃;

[0152] Step 12: Is the valve opening of the refrigeration side loop of the unit to be reduced 0? If yes, proceed to step 13; otherwise, re-judge step 12 after an interval of time t;

[0153] Among them, the time t is selected according to the actual engineering situation, and the default value is 2min;

[0154] Step 13: Let the operating unit water supply temperature setting value Tygx=the operating unit water supply temperature initial setting value Tygx0;

[0155] Among them, Tygx is the set value of the water supply temperature of the running unit, and Tygx0 is the initial set value of the water supply temperature of the running unit;

[0156] Step 14: When reducing the machine again, the water temperature control mode is turned on by default and go to step 5.

[0157] For ease of understanding, the present application also provides an embodiment of adding a machine to an air conditioning system in a practical application. Figure 3 As shown, this embodiment includes the following equipment: 1 cooling tower, 4 cooling water pumps, 4 chillers, 4 freezing water pumps, and several temperature sensors.

[0158] Here’s how it works:

[0159] The system includes cooling water and chilled water loops. The evaporator 2 is connected to the chilled water loop. The low-temperature chilled water is supplied from the evaporator to the end user for heat exchange to achieve cooling, and then transported back to the evaporator by the chilled water pump 4; the condenser 3 is connected to the cooling water loop. The high-temperature cooling water is transported from the condenser to the cooling tower under the power of the cooling pump to dissipate heat, and then returns to the condenser to continue heat exchange.

[0160] Read parameters: Read C=4.2kJ / kg·°C, Min=431.3L / s, Tdg=12℃, the number of units currently in operation is 3, Qz=8440*3=25322kW, Tygx=7℃, the minimum water flow rate of the first chiller to be added Min=431m³ / h, the current operating water flow rate of the second chiller to be reduced Mj=650m³ / h;

[0161] Input Tgmax=8℃, Tgmin=6℃;

[0162] When the system is added, Tg=9℃>Tgmax, the water temperature control mode is turned on;

[0163] Calculate Qmin=4.2*431*(12-8) / 3.6=2011kW; Xy=1-2011 / 25322=0.92=92%;

[0164] When X<92%-5%=87%, record Tygx0=7℃, and set Tygx=6℃;

[0165] Controlling the first chiller to be added to the air conditioning system to start, and the corresponding refrigeration pump to operate at a minimum frequency of 25 Hz;

[0166] When Tg>8-0.5=7.5℃, let Tygx=6-0.5=5.5℃, and re-judge Tg>7.5℃ after an interval of 2 minutes?

[0167] When Tg<8-0.5=7.5℃, it is judged that Tdg<8℃ at this moment. If it is not satisfied, it is judged again after 2 minutes that Tdg<8℃? If it is satisfied, Tygx=7℃, and the corresponding refrigeration pump resumes the group control system fixed supply and return water pressure difference control;

[0168] After that, the water temperature control mode will be turned on by default each time a machine is added.

[0169] When the system reduces the number of machines, Tg=9℃>Tgmax, the water temperature control mode is turned on;

[0170] Calculate Qmin=4.2*650*(8-7) / 3.6=758kW; Xy=1-758 / 16880=95%;

[0171] When X<95%-5%=90%, record Tygx0=7℃, and set Tygx=6℃;

[0172] Turn off the second chiller and the pumps and valves of the corresponding water circuits;

[0173] When Tg>8-0.5=7.5℃, let Tygx=6-0.5=5.5℃, and re-judge Tg>7.5℃ after an interval of 2 minutes?

[0174] When Tg<8-0.5=7.5℃, it is judged that the valve opening of the refrigeration side loop of the unit to be reduced is 0. If it is not satisfied, it is re-judged after an interval of 2 minutes. If it is satisfied, Tygx=7℃;

[0175] After that, the water temperature control mode will be turned on by default each time the machine is reduced.

[0176] In another embodiment of the present application, a water temperature control device is also provided, such as Figure 4 As shown, including:

[0177] In another embodiment of the present application, a water temperature control device is provided, comprising:

[0178] An acquisition module 11 is used to acquire a target adjustment method for the number of operating units in the air-conditioning system and an actual load rate of the operating units;

[0179] A determination module 12, configured to determine a reserved load rate of the operating units in the air-conditioning system based on the target adjustment method, wherein the reserved load rate is determined according to a load required to eliminate water temperature fluctuations caused by adjusting the number of operating units;

[0180] A reducing module 13, configured to reduce the outlet water temperature of the operating unit if the actual load rate is less than or equal to the reserved load rate;

[0181] The adjustment module 14 is used to adjust the number of the operating units according to the target adjustment method after the outlet water temperature of the operating units is reduced, and adjust the main pipe water supply temperature of the air-conditioning system to a preset temperature range based on the target adjustment method.

[0182] In another embodiment of the present application, a control device is further provided, comprising a processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory communicate with each other via the communication bus;

[0183] Memory, used to store computer programs;

[0184] The processor is used to implement the water temperature control method described in any of the above method embodiments when executing the program stored in the memory.

[0185] In the control device provided by the embodiment of the present invention, the processor determines whether the water temperature fluctuation occurring when adding a machine is within the allowable range by executing the program stored in the memory. If it exceeds the allowable range, the water temperature control mode is turned on, and the reserved load rate of the operating unit is calculated. When the operating unit reaches the reserved load rate, the outlet water temperature of the operating unit is reduced, and the adding process is executed. At the same time, the water pump and valve control are combined to control the stability of the water supply temperature, which not only eliminates the temperature fluctuation during the adding and subtracting process, but also ensures the temperature control accuracy, realizes the dual optimization of system performance and production efficiency, ensures the temperature control requirements of the production process, and thus improves production efficiency and product yield.

[0186] The communication bus 1140 mentioned in the above control device can be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus. The communication bus 1140 can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 5 Only one thick line is used in the diagram, but this does not mean that there is only one bus or only one type of bus.

[0187] The communication interface 1120 is used for communication between the above control device and other devices.

[0188] The memory 1130 may include a random access memory (RAM) or a non-volatile memory, such as at least one disk memory. Optionally, the memory may also be at least one storage device located away from the aforementioned processor.

[0189] The above-mentioned processor 1110 can be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it can also be a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components.

[0190] In yet another embodiment of the present application, an air conditioning system is provided, comprising the control device as described in the above embodiment.

[0191] It should be noted that, in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0192] The foregoing is merely a specific embodiment of the present invention, which enables those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A water temperature control method, characterized in that: include: Obtaining a target adjustment method for the number of operating units in the air-conditioning system and an actual load rate of the operating units, wherein the target adjustment method includes: adding a chiller to the air-conditioning system and reducing a chiller to the air-conditioning system; Determining a reserved load rate of the operating units in the air-conditioning system based on the target adjustment method, wherein the reserved load rate is determined according to the load required to eliminate water temperature fluctuations caused by adjusting the number of operating units; Determining the reserved load rate of the operating units in the air-conditioning system based on the target adjustment method includes: Obtaining the minimum load calculation parameters corresponding to the target adjustment method, wherein obtaining the minimum load calculation parameters corresponding to the target adjustment method includes: if the target adjustment method is to add a chiller to the air-conditioning system, obtaining the minimum water flow rate of the first chiller to be added, the water temperature of the water supply loop of the first chiller, and the upper limit of the main pipe water supply temperature, as the minimum load calculation parameters; or, if the target adjustment method is to reduce the chiller to the air-conditioning system, obtaining the current operating water flow rate of the second chiller to be reduced, the water temperature of the water supply loop of the second chiller, and the upper limit of the main pipe water supply temperature, as the minimum load calculation parameters; Calculate the minimum operating load of the unit to be adjusted according to the minimum load calculation parameters; Obtaining the total rated cooling capacity of the operating units in the air-conditioning system; Calculating the reserved load rate according to the minimum operating load and the sum of the rated cooling capacity; If the actual load rate is less than or equal to the reserved load rate, lowering the outlet water temperature of the operating unit; After the outlet water temperature of the operating units is lowered, the number of the operating units is adjusted according to the target adjustment method, and the main pipe water supply temperature of the air-conditioning system is adjusted to a preset temperature range based on the target adjustment method. The preset temperature range is a temperature range between an upper limit value and a lower limit value of the main pipe water supply temperature.

2. The water temperature control method according to claim 1, characterized in that: Calculating the minimum operating load of the unit to be adjusted according to the minimum load calculation parameters includes: Calculating the minimum operating load of the first chiller according to the minimum water flow of the first chiller, the water temperature of the water supply loop of the first chiller and the upper limit of the main pipe water supply temperature; or, The minimum operating load of the second chiller is calculated based on the current operating water flow of the second chiller, the water temperature of the water supply loop of the second chiller and the upper limit of the main pipe water supply temperature.

3. The water temperature control method according to claim 1, characterized in that: Adjusting the number of the operating units according to the target adjustment method includes: If the target adjustment method is to add a chiller to the air-conditioning system, control the first chiller to be added to the air-conditioning system to start, and control the chilled water pump of the first chiller to operate at a minimum frequency; or, If the target adjustment method is to reduce the number of chillers in the air-conditioning system, the second chiller to be reduced from the air-conditioning system is controlled to be turned off.

4. The water temperature control method according to claim 1, characterized in that: Adjusting the main pipe water supply temperature of the air conditioning system to a preset temperature range based on the target adjustment method includes: Get the current main water supply temperature; Determine whether the current main pipe water supply temperature is less than the main pipe water supply temperature upper limit value; If the current main pipe water supply temperature is less than the main pipe water supply temperature upper limit value, determine whether the adjusted unit has reached the primary adjustment target based on the target adjustment method, and the determination of whether the adjusted unit has reached the primary adjustment target based on the target adjustment method includes: determining whether the water supply loop water temperature of the first chiller added to the air-conditioning system is less than the main pipe water supply temperature upper limit value; if the water supply loop water temperature is less than the main pipe water supply temperature upper limit value, determine that the first chiller has reached the primary adjustment target; or, determine whether the freezing side loop valve opening of the second chiller removed from the air-conditioning system is 0; if the freezing side loop valve opening of the second chiller is 0, determine that the second chiller has reached the primary adjustment target; if the adjusted unit has reached the primary adjustment target, adjust the water supply temperature of the operating unit of the air-conditioning system to the initial setting value of the water supply temperature of the operating unit; If the current main water supply temperature is greater than or equal to the main water supply temperature upper limit, the water supply temperature of the operating units of the air-conditioning system is adjusted to the main water supply temperature lower limit, and after a preset time period, the step of determining whether the current main water supply temperature is less than the main water supply temperature upper limit is re-executed.

5. The water temperature control method according to claim 1, characterized in that: The method further comprises: If an adjustment instruction for the number of operating units in the air conditioning system is received, determining whether the current main pipe water supply temperature is greater than the main pipe water supply temperature upper limit value; If the current main pipe water supply temperature is greater than the main pipe water supply temperature upper limit value, the step of obtaining a target adjustment method for the number of operating units in the air-conditioning system and an actual load rate of the operating units is executed.

6. A water temperature control device, characterized in that: include: An acquisition module, used for acquiring a target adjustment method for the number of operating units in the air-conditioning system and an actual load rate of the operating units, wherein the target adjustment method includes: adding a chiller to the air-conditioning system and reducing a chiller to the air-conditioning system; A determination module is used to determine the reserved load rate of the operating units in the air-conditioning system based on the target adjustment method, and the reserved load rate is determined according to the load required to eliminate the water temperature fluctuation caused by adjusting the number of operating units; determining the reserved load rate of the operating units in the air-conditioning system based on the target adjustment method includes: obtaining the minimum load calculation parameters corresponding to the target adjustment method, and obtaining the minimum load calculation parameters corresponding to the target adjustment method includes: if the target adjustment method is to add a chiller to the air-conditioning system, obtaining the minimum water flow rate of the first chiller to be added, the minimum water flow rate of the first chiller The water temperature of the water supply loop of the group and the upper limit of the water supply temperature of the main pipe are used as the minimum load calculation parameters; or, if the target adjustment method is to reduce the chiller in the air-conditioning system, the current operating water flow of the second chiller to be reduced, the water temperature of the water supply loop of the second chiller and the upper limit of the water supply temperature of the main pipe are obtained as the minimum load calculation parameters; the operating minimum load of the unit to be adjusted is calculated according to the minimum load calculation parameters; the sum of the rated cooling capacities of the operating units in the air-conditioning system is obtained; the reserved load rate is calculated according to the operating minimum load and the sum of the rated cooling capacities; A reduction module, used for reducing the outlet water temperature of the operating unit if the actual load rate is less than or equal to the reserved load rate; The adjustment module is used to adjust the number of the operating units according to the target adjustment method after the outlet water temperature of the operating units is reduced, and adjust the main pipe water supply temperature of the air-conditioning system to a preset temperature range based on the target adjustment method. The preset temperature range is a temperature range between an upper limit value of the main pipe water supply temperature and a lower limit value of the main pipe water supply temperature.

7. A control device, characterized in that: It includes a processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory communicate with each other through the communication bus; Memory, used to store computer programs; The processor is used to implement the water temperature control method described in any one of claims 1 to 5 when executing the program stored in the memory.

8. An air conditioning system, characterized in that: Comprising a control device as claimed in claim 7.

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