Control method and device of heating ventilation air conditioning system

Abstract

The invention discloses a control method and device for a heating ventilation air conditioning system. The method comprises the steps that the first load demand quantity of the current period, unit state information and the first operation unit number of the previous period before the current period and closest to the current period are obtained; under the condition that it is determined that the first operation unit number meets the first load demand quantity and the heating ventilation air conditioning system is in a steady state, the unit demand quantity of the current period is determined according to the first load demand quantity and the unit state information; under the condition that it is determined that the first operation unit number meets the first load demand quantity and the heating ventilation air conditioning system is in an unstable state, the first operation unit number is determined as the unit demand quantity of the current period; and adjusting the running unit in the current period according to the unit demand. The problem that the number of the units cannot be flexibly adjusted can be effectively solved, dynamic adjustment of the number of the units is achieved, the possibility that the number of the operating units is matched with actual requirements can be improved, and the operating efficiency of the heating ventilation air conditioning system can be improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of HVAC control, and in particular relates to a control method and device for a HVAC system. Background Art

[0002] As an important system responsible for ventilation and air conditioning in buildings, the HVAC system uses water and air as the medium to transmit cold and heat through pipes to achieve precise control of indoor temperature. In this process, precise control of water temperature and reasonable setting of the number of operating units are particularly critical.

[0003] The number of units in operation is directly related to the energy efficiency of the HVAC system. Too many units will increase the energy consumption and operating costs of the system, while insufficient units may not be able to meet the load requirements of the building.

[0004] However, the current HVAC system unit number setting often relies on manual experience, but the heat load or cooling load of a building is affected by many factors, such as changes in the outdoor environment, the activities of indoor personnel, and the operating status of the equipment, all of which may cause real-time load fluctuations. The traditional manual setting method cannot be flexibly adjusted according to these real-time changes, which often leads to a mismatch between the number of units and the actual load demand, thereby reducing the system's operating efficiency. Summary of the invention

[0005] The embodiments of the present invention provide a control method and device for a HVAC system, which can realize dynamic adjustment of the number of operating units and effectively improve the operating efficiency of the HVAC system.

[0006] In a first aspect, an embodiment of the present application provides a method for controlling a HVAC system, the method comprising:

[0007] Obtain the first load demand of the current cycle, unit status information, and the number of first operating units in the previous cycle that is placed before the current cycle and is closest to the current cycle;

[0008] When it is determined that the first number of operating units meets the first load demand and the HVAC system is in a steady state, determining the unit demand of the current cycle according to the first load demand and the unit state information;

[0009] When it is determined that the first number of operating units meets the first load demand and the HVAC system is in a non-steady state, determining the first number of operating units as the unit demand of the current cycle;

[0010] Adjust the operating units in the current cycle according to the unit demand.

[0011] As an optional implementation, before determining that the first number of operating units meets the first load demand and the HVAC system is in a steady state, the method further includes:

[0012] Obtain the unit temperature control information of the current cycle, which includes the unit set temperature, the unit actual water supply temperature and the unit temperature change rate;

[0013] Obtain the number of second operating units within the preset time period to which the previous cycle belongs;

[0014] When the number of the second operating units is the same as the number of the first operating units and the unit temperature control information meets the first preset condition, it is determined that the HVAC system is in a steady state. The first preset condition includes at least one of the following: the difference between the unit set temperature and the actual water supply temperature of the unit is less than the first preset threshold, and the unit temperature change rate is less than the second preset threshold.

[0015] As an optional implementation, before determining that the first number of operating units meets the first load demand and the HVAC system is in a steady state, the method further includes:

[0016] Obtain the unit set temperature, unit actual water supply temperature and unit temperature change rate of the current cycle;

[0017] When the difference between the set temperature of the unit and the actual water supply temperature of the unit is greater than the third preset threshold and the temperature change rate of the unit is lower than the fourth preset threshold, it is determined that the first number of operating units meets the first load demand.

[0018] As an optional implementation, the method further includes:

[0019] When it is determined that the first number of operating units does not meet the first load demand, the unit demand of the current cycle is determined according to the first load demand and the unit power of a single unit.

[0020] As an optional implementation manner, obtaining the first load demand of the current cycle includes:

[0021] Obtain the second load demand of the previous cycle, the unit thermal load of the current cycle, and the environmental information of the energy supply area;

[0022] When it is determined that the HVAC system is in a non-dehumidification mode and in a steady state, the unit thermal load is determined as the first load demand of the current cycle;

[0023] When it is determined that the HVAC system is in a non-dehumidification mode and a non-steady state, the second load demand is determined as the first load demand of the current cycle.

[0024] As an optional implementation method, obtaining the unit thermal load of the current cycle includes:

[0025] Acquire the actual return water temperature, actual supply water temperature, water flow rate of the running unit in the current cycle and the first reference heat exchange amount of the running unit determined by the sensor installed on the running unit;

[0026] Determine a second reference heat exchange amount according to the actual return water temperature, the actual supply water temperature and the water flow rate;

[0027] The larger value of the first reference heat exchange amount and the second reference heat exchange amount is determined as the thermal load of the unit in the current cycle.

[0028] As an optional implementation manner, obtaining the first load demand of the current cycle includes:

[0029] Obtain the return air ratio of the HVAC system, the indoor ambient air enthalpy of the energy supply area, and the outdoor ambient air enthalpy;

[0030] Determine the mixed air enthalpy value according to the return air ratio, the indoor ambient air enthalpy value and the outdoor ambient air enthalpy value;

[0031] When it is determined that the HVAC system is in dehumidification mode, the first load demand E of the current cycle is determined according to the following expression:

[0032] E=m air ·(h mix -h dew )

[0033] In the formula, h dew is the enthalpy value of the humid air at the dew point temperature corresponding to the indoor temperature and humidity setting value when it reaches the saturated state, m air is the mass flow rate of air entering the air conditioning system, h mix is the enthalpy of mixed air.

[0034] As an optional implementation method, obtaining the set temperature of the unit in the current cycle includes:

[0035] Obtain the return air ratio of the HVAC system, the indoor air humidity content of the energy supply area, the outdoor air humidity content, the indoor ambient air enthalpy value and the outdoor ambient air enthalpy value;

[0036] Determine the mixed air enthalpy value according to the return air ratio, the indoor ambient air enthalpy value and the outdoor ambient air enthalpy value;

[0037] Determine the mixed air humidity content based on the return air ratio, indoor air humidity content and outdoor air humidity content;

[0038] determining the terminal air inlet temperature according to a conversion function of the mixed air moisture content, the mixed air enthalpy value and the first wet air parameter;

[0039] The unit set temperature is determined based on the terminal air inlet temperature and the first load demand.

[0040] As an optional implementation, determining the set temperature of the unit according to the terminal air inlet temperature and the first load demand includes:

[0041] Solve the unit set temperature according to the following expression

[0042]

[0043] Where E is the first load demand, is the terminal air inlet temperature, G water is the chilled water flow rate, G air is the air flow rate, Q 0 is the load calibration quantity, is the inlet temperature calibration quantity, is the unit outlet water temperature calibration quantity, is the chilled water flow calibration quantity, The air flow calibration quantity.

[0044] In a second aspect, a control device for a heating, ventilation and air conditioning system is provided, the device comprising:

[0045] A first acquisition module is used to acquire the first load demand of the current cycle, the unit status information, and the number of first operating units in the previous cycle that is placed before the current cycle and is closest to the current cycle;

[0046] A first determination module is used to determine the unit demand of the current cycle according to the first load demand and the unit state information when it is determined that the number of the first operating units meets the first load demand and the HVAC system is in a steady state;

[0047] A second determination module is used to determine the first number of operating units as the unit demand of the current cycle when it is determined that the first number of operating units meets the first load demand and the HVAC system is in a non-steady state;

[0048] The adjustment module is used to adjust the operating units in the current cycle according to the unit demand.

[0049] In a third aspect, an embodiment of the present application provides an electronic device, which includes a processor, a memory, and a program or instruction stored in the memory and executable on the processor, wherein when the program or instruction is executed by the processor, the steps of the method for controlling a HVAC system of any one of the first aspects of the present application are implemented.

[0050] In a fourth aspect, an embodiment of the present application provides a computer storage medium, on which a program or instruction is stored. When the program or instruction is executed by a processor, the control method of the HVAC system of any one of the first aspects of the present application is implemented.

[0051] In a fifth aspect, an embodiment of the present application provides a computer program product, which includes a computer program, and when the computer program is processed and executed, it implements the control method of the HVAC system of any one of the first aspects of the present application.

[0052] The control method and device of the HVAC system of the embodiment of the present application can obtain the first load demand and unit status information of the current cycle in real time, and can adjust the unit demand according to the actual first load demand and unit status information when the first number of operating units meets the first load demand and the HVAC system runs smoothly, which helps to obtain a unit demand that is more suitable for the actual load demand. When the first number of operating units meets the first load demand and the HVAC system runs unsteadily, using the first number of operating units in the previous cycle as the operating units in the current cycle helps to maintain the stability of the system and avoid frequent unit switching that causes unstable system operation. Further, adjusting the operating units of the current cycle by the unit demand can ensure that the HVAC system responds quickly to load changes, so that the HVAC system matches the actual demand more accurately, and effectively solves the problem of the inability to flexibly adjust the number of units in the related technology. This dynamic adjustment of the number of units can increase the possibility of matching the number of operating units with the actual demand, and can effectively improve the operating efficiency of the HVAC system. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] In order to more clearly illustrate the technical solution of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0054] Figure 1 is a flow chart of a control method of a HVAC system provided by an embodiment of the present application;

[0055] Figure 2 It is a flowchart of a specific implementation method of S102 provided in an embodiment of the present application;

[0056] Figure 3 It is a flowchart of a specific implementation method of S104 provided in an embodiment of the present application;

[0057] Figure 4This is a flowchart of a specific implementation method of obtaining the first load demand in S101 provided in an embodiment of the present application;

[0058] Figure 5 This is a flowchart of a specific implementation method of obtaining the thermal load of the unit in S401 provided in an embodiment of the present application;

[0059] Figure 6 It is a flowchart of another specific implementation method of obtaining the first load demand in S101 provided in an embodiment of the present application;

[0060] Figure 7 This is a flowchart of a specific implementation method of obtaining the set temperature of the unit in the current cycle in S1021 provided in an embodiment of the present application;

[0061] Figure 8 It is a specific implementation scenario provided by an embodiment of the present application;

[0062] Fig. 9 is a structural schematic diagram of a control device for a HVAC system provided by an embodiment of the present application;

[0063] Fig.10 It is a schematic diagram of the structure of an electronic device provided by an embodiment of the present application. DETAILED DESCRIPTION

[0064] The features and exemplary embodiments of various aspects of the present application will be described in detail below. In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain the present application, rather than to limit the present application. For those skilled in the art, the present application can be implemented without the need for some of these specific details. The following description of the embodiments is only to provide a better understanding of the present application by illustrating the examples of the present application.

[0065] It should be noted that, in this article, relational terms such as first and second, etc. 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 statement "include..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0066] HVAC systems usually have two functions, cooling and heating, to meet people's needs for indoor environmental comfort in different seasons and climate conditions. It mainly uses water or air as a heat transfer medium to transfer cold and heat in pipes. Specifically, in summer or when cooling is required, the HVAC system provides cooling through a refrigeration cycle. It uses a refrigeration unit to produce low-temperature chilled water, which is transported to various areas of the building through pipes. In the air-conditioning box, the chilled water exchanges heat with the air, so that the air is cooled and sent indoors, thereby reducing the indoor temperature. In winter or when heating is required, the HVAC system provides heating through a heating cycle. It uses a boiler or a hot water unit to produce high-temperature hot water, which is also transported to various areas of the building through pipes. In the air-conditioning box, the hot water exchanges heat with the air, so that the air is heated and sent indoors, thereby increasing the indoor temperature.

[0067] At present, HVAC systems still mostly rely on traditional manual experience when setting the number of units. However, this method is incapable of dealing with real-time fluctuations in building heat load or cooling load. These load fluctuations are often affected by a variety of factors, including but not limited to sudden changes in the outdoor environment, changes in indoor personnel activities, and adjustments to the operating status of equipment. Since these factors are constantly changing, it is difficult for traditional manual setting methods to adjust the number of units in real time and accurately, so the number of units often does not match the actual load demand. This not only affects the operating efficiency of the system, but may also cause energy waste.

[0068] In order to solve the above technical problems, the embodiment of the present application provides a control method and device for a HVAC system. The control method for a HVAC system provided by the embodiment of the present application is first introduced below.

[0069] Figure 1 FIG. 1 is a flow chart of a method for controlling a HVAC system provided by an embodiment of the present application. Figure 1As shown, the control method of the HVAC system provided in the embodiment of the present application may include the following steps: S101 to S107.

[0070] S101, obtaining the first load demand of the current cycle, unit status information, and the number of first operating units in the previous cycle that is before the current cycle and closest to the current cycle;

[0071] S102, determining whether the number of the first operating units meets the first load demand. If it is determined that the number of the first operating units does not meet the first load demand, executing S103. If it is determined that the number of the first operating units meets the first load demand, executing S104.

[0072] S103, determining the unit demand of the current cycle according to the first load demand and the unit power of a single unit, and executing S107;

[0073] S104, determining whether the HVAC system is in a steady state, and if it is determined that the HVAC system is in a steady state, executing S105, and if it is determined that the HVAC system is in a non-steady state, executing S106;

[0074] S105, determining the unit demand of the current cycle according to the first load demand and the unit status information, and executing S107;

[0075] S106, determining the first number of operating units as the unit demand in the current cycle, and executing S107;

[0076] S107, adjusting the operating units of the current cycle according to the unit demand.

[0077] By acquiring the first load demand and unit status information of the current cycle in real time, the unit demand can be adjusted according to the actual first load demand and unit status information when the first number of operating units meets the first load demand and the HVAC system operates smoothly, which helps to obtain a unit demand that is more suitable for the actual load demand. When the first number of operating units meets the first load demand and the HVAC system operates unsteadily, using the first number of operating units in the previous cycle as the operating units in the current cycle helps maintain the stability of the system and avoid frequent unit switching that leads to unstable system operation. Furthermore, adjusting the operating units of the current cycle by unit demand can ensure that the HVAC system responds quickly to load changes, so that the HVAC system matches the actual demand more accurately, and solves the problem that the number of units cannot be flexibly adjusted in traditional methods. This dynamic adjustment of the number of units can increase the possibility of matching the number of operating units with actual demand, and can effectively improve the operating efficiency of the HVAC system.

[0078] In some embodiments, in S101, a cycle may refer to different time units and time lengths. The length and unit of the cycle may be adjusted according to the specific needs of the user and the frequency of data collection. As an example, a cycle may include a cycle in minutes and a cycle in hours. The first load demand refers to the total cooling or heating required to be provided by the HVAC system in the current cycle, that is, the load demand of the HVAC system in the current cycle. The first number of operating units refers to the number of units started for the first time in the current cycle. In the current cycle, the number of units put into operation in the HVAC system is usually the same as the number of first operating units put into operation in the previous cycle closest to the current cycle.

[0079] In some embodiments, the unit status information may include the rated power and actual working load factor of the unit. The rated power of the unit refers to the maximum power that the unit can continuously output under standard conditions. The actual working load factor refers to the ratio of the load borne by the unit during actual operation to its rated power. The actual working load factor reflects the load condition of the unit during actual operation, which is usually less than 1.

[0080] In some embodiments, in S102, it can be determined whether the first operating unit meets the first load demand based on whether an additional unit needs to be added. Figure 2 As shown, the aforementioned S102 may specifically include the following steps: S1021 to S1024.

[0081] S1021, obtaining the set temperature of the unit, the actual water supply temperature of the unit, and the temperature change rate of the unit in the current cycle;

[0082] S1022, determining whether the difference between the set temperature of the unit and the actual water supply temperature of the unit is greater than a third preset threshold and whether the temperature change rate of the unit is lower than a fourth preset threshold. If the determination result is yes, execute S1023; if the determination result is no, execute S1024;

[0083] S1023, determining that the number of the first operating units meets the first load demand;

[0084] S1024, determining that the first number of operating units does not meet the first load demand.

[0085] In some embodiments, in S1021, during specific implementation, the set temperature of the unit in each cycle can be recorded and stored in a database. The actual water supply temperature of the unit can be determined based on the actual measured temperature of the current outlet water. The actual measured temperature of the current outlet water can be obtained by installing a temperature sensor in the HVAC system for real-time monitoring.

[0086] The unit temperature change rate refers to the rate at which the temperature in the unit changes per minute, usually expressed in ℃ / min. It can include the cooling rate and heating rate. The cooling rate refers to the rate at which the water supply temperature decreases in summer, while the heating rate refers to the rate at which the water supply temperature increases in winter.

[0087] In some embodiments, in S1022, the third preset threshold and the fourth preset threshold can be determined according to the climatic conditions of the unit. By setting a suitable third preset threshold and fourth preset threshold, it can be effectively ensured that the increase in the unit's power-on is based on the trend of the unit's temperature change, rather than from short-term fluctuations in the unit.

[0088] It is worth mentioning here that the unit number control module is a module used to manage the number of operating units in the HVAC system. The module is divided into winter / summer mode and transition season mode according to seasonal changes. In the transition season, the unit is in a closed state, and the number of water pumps on the ground source side can be adjusted accordingly according to the temperature difference change to achieve energy-saving operation. In the summer and winter modes, the third preset threshold and the fourth preset threshold can be set by the user based on local climate conditions, building characteristics, and historical data of system operation.

[0089] In some embodiments, when the difference between the set temperature of the unit and the actual water supply temperature of the unit is large and the temperature change rate of the unit is low, it usually means that the operation of the HVAC system is stable, and the difference between the actual water supply temperature of the unit and the set temperature of the unit is within a controllable range. In this case, the first number of operating units is sufficient to meet the load demand of the system, because the system can stably maintain the set temperature, and the temperature changes slowly, and no additional units are required to cope with sudden load changes. When the difference between the set temperature of the unit and the actual water supply temperature of the unit is small, or the temperature change rate of the unit is high, it may mean that the load demand of the system increases suddenly. In this case, the first number of operating units may not be able to meet the load demand of the system, and it is necessary to increase the number of units to cope with the instability of the system operation. Therefore, according to the difference between the set temperature of the unit and the actual water supply temperature of the unit and the temperature change rate of the unit, it can be more accurately judged whether the current operating state of the HVAC system and the number of units are sufficient to meet the load demand.

[0090] In some embodiments, in S103, when it is determined that the first number of operating units does not meet the first load demand, the first load demand is divided by the unit power of a single unit and then rounded up to obtain the unit demand for the current cycle, thereby ensuring that the selected number of units is sufficient to meet the actual first load demand, thereby effectively avoiding the occurrence of insufficient number of units.

[0091] In some embodiments, Figure 3As shown, the aforementioned S104 may specifically include the following steps: S1041 to S1044.

[0092] S1041, obtaining the unit temperature control information of the current cycle, where the unit temperature control information includes the unit set temperature, the unit actual water supply temperature, and the unit temperature change rate.

[0093] Among them, the unit set temperature, the unit actual water supply temperature and the unit temperature change rate of the current cycle are the same as those of the aforementioned S1021. For details, please refer to the specific details of the aforementioned S1021, which will not be repeated here.

[0094] S1042, obtaining the number of second operating units in the preset time period to which the previous cycle belongs.

[0095] The preset time period may be equal to or greater than the time length of the previous cycle, and the preset time period is customized by the user according to actual needs and is not limited here. The second number of operating units refers to the number of units put into operation within the preset time period.

[0096] S1043, determine whether the number of the second operating units is the same as the number of the first operating units. If the judgment result is no, proceed to S1044; if the judgment result is yes, proceed to S1045.

[0097] In some embodiments, the load demand of the energy supply area of ​​the HVAC system may change, and the HVAC system may need to increase or decrease the operation of the units to meet the load demand. If the second number of operating units is the same as the first number of operating units, it means that the unit demand of the energy supply area has not changed within the preset time period, that is, the HVAC system is in a suspected steady state.

[0098] S1044, determine that the HVAC system is in a non-steady state.

[0099] S1045, determine whether the unit temperature control information meets the first preset condition, the first preset condition includes at least one of the following: the difference between the unit set temperature and the unit actual water supply temperature is less than the first preset threshold, and the unit temperature change rate is less than the second preset threshold. If the judgment result is yes, execute S1046, if the judgment result is no, execute S1044.

[0100] S1046, determine that the HVAC system is in a steady state.

[0101] Among them, the first preset threshold and the second preset threshold can be customized by the user according to experience or actual needs, and are not limited here. When the difference between the set temperature of the unit and the actual water supply temperature of the unit is less than the first preset threshold, it indicates that the temperature control accuracy of the HVAC system is high, and the temperature output by the HVAC system is very close to the temperature set by the user, that is, the HVAC system is in a stable operating state. When the temperature change rate of the unit is less than the second preset threshold, it indicates that the temperature fluctuation of the HVAC system is small, and the temperature adjustment of the unit is stable, that is, the HVAC system is in a stable operating state.

[0102] Steady state means that the operation state of the HVAC system is relatively stable, and the unit demand and temperature control information are in line with expectations, without obvious fluctuations or changes. Therefore, when it is determined that the HVAC system is in a suspected steady state, by judging the unit temperature control information, it is possible to accurately determine whether the HVAC system is in a steady state, that is, whether the unit cooling capacity is balanced with the cooling load of the energy supply area or whether the unit heating capacity is balanced with the heat load of the energy supply area.

[0103] In the embodiment of the present application, the change in the unit demand will affect the heating or cooling capacity of the HVAC system. The unit temperature control information satisfies the first preset condition, indicating that the temperature adjustment of the unit is stable. By introducing the unit temperature control information and the second number of operating units within the preset time period to make a steady-state judgment of the HVAC system, not only the stability of the number of units in the HVAC system is considered, but also the stability of the operating state of the units in the HVAC system is further considered, which can more comprehensively reflect the actual operating conditions of the HVAC system, thereby effectively improving the accuracy of the judgment on whether the HVAC system is in a steady state.

[0104] Next, in S105, as a specific example, when it is determined that the HVAC system is in a steady state, the unit demand of the current cycle can be calculated by formula (1):

[0105]

[0106] In formula (1), P cool represents the rated power of the unit, β is the actual workload factor of the unit (the value is less than 1), and ceil represents rounding up.

[0107] In S106, when it is determined that the HVAC system is in a non-steady state, the first number of operating units can be determined as the unit demand of the current cycle. The HVAC system will respond to the demand more quickly, which helps to maintain the stability of the system and avoid frequent unit switching that may lead to unstable system operation, thereby helping to improve efficiency, so as to maximize the operating efficiency of the HVAC system and ensure normal operation of the system.

[0108] In S107, adjusting the operating units in the current cycle according to the actual unit demand can effectively avoid unnecessary energy waste and improve the energy utilization efficiency of the system.

[0109] In some embodiments, Figure 4 As shown, obtaining the first load demand of the current cycle in S101 may specifically include the following steps: S401 to S404.

[0110] S401, obtaining the second load demand of the previous cycle, the thermal load of the unit in the current cycle, and the environmental information of the energy supply area.

[0111] In some embodiments, the previous cycle may refer to the previous cycle closest to the current cycle, where the cycle may refer to different time units and time lengths. The HVAC system is usually equipped with a special monitoring device or system to record and store load data within each cycle. By consulting these records, the second load demand of the previous cycle can be obtained. In addition, the second load demand of the previous cycle can also be obtained by manual recording and calculation. The thermal load of the unit refers to the amount of cooling or heat provided by the refrigeration equipment or heating equipment per unit time, usually expressed in unit power, specifically, it can include the cooling capacity of the unit and the heating capacity of the unit. The environmental information of the energy supply area may include temperature information and humidity information. The environmental information of the energy supply area can be obtained through meteorological station data and sensor monitoring.

[0112] S402, determining a mode of a HVAC system according to environmental information of a power supply area.

[0113] In some embodiments, the HVAC system mode may include a summer dehumidification mode, a summer non-dehumidification mode, and a winter mode. In the summer mode, if the dew point temperature corresponding to the indoor temperature and humidity setting value is greater than the outdoor environment dew point temperature, the dehumidification mode is turned on, otherwise the non-dehumidification mode is turned on.

[0114] S403: When it is determined that the HVAC system is in a non-dehumidification mode and a steady state, the thermal load of the unit is determined as the first load demand of the current cycle.

[0115] In some embodiments, if there is a dehumidification demand in the system, the energy consumption of the dehumidification process will also affect the overall load of the system. The energy consumed in the dehumidification process will increase the total thermal load of the system. Therefore, when determining the thermal load of the unit, it is necessary to consider the impact of the dehumidification process on the load to ensure that the system can operate effectively. Under steady-state conditions, the system operation state is relatively stable, which means that the load demand of the current cycle is relatively stable. The thermal load of the unit in the current cycle can be used to approximate the first load demand of the current cycle.

[0116] S404: When it is determined that the HVAC system is in a non-dehumidification mode and a non-steady state, determine the second load demand as the first load demand of the current cycle.

[0117] In some embodiments, if there is no dehumidification demand in the system, under non-steady-state conditions, the unit thermal load of the current cycle is also relatively unstable. In this case, the unit thermal load of the current cycle cannot be used to directly represent the first load demand of the current cycle, which may cause the system load to fluctuate greatly in a short period of time and increase the instability of system operation. Therefore, the second load demand of the previous cycle should be determined as the first load demand of the current cycle to smooth the load fluctuation.

[0118] By monitoring the steady state of the HVAC system and implementing the corresponding plan according to the corresponding steady state to calculate the first load demand of the energy supply area in the current cycle, the current load characteristics and demand changes of the energy supply area can be predicted and met more accurately.

[0119] In some embodiments, Figure 5 As shown, obtaining the thermal load of the unit in the current cycle in S401 may specifically include the following steps: S4011 to S4013.

[0120] S4011, obtaining the actual return water temperature, actual supply water temperature, water flow rate of the operating unit in the current cycle and the first reference heat exchange amount of the operating unit determined by the sensor installed on the operating unit.

[0121] In some embodiments, a temperature sensor and a flow meter may be installed on the running unit to monitor the actual return water temperature, actual supply water temperature, and water flow rate of the running unit. The actual return water temperature may refer to the temperature of the water returned from the unit equipment to the HVAC system, and specifically, may be measured by a temperature sensor installed in the water collector at the return water outlet of the unit equipment. The actual supply water temperature refers to the temperature of the water delivered from the heat source / cold source to the user end (such as a radiator / air outlet, etc.) by the unit equipment.

[0122] S4012, determining a second reference heat exchange amount according to the actual return water temperature, the actual supply water temperature and the water flow rate.

[0123] In some embodiments, the actual return water temperature, the actual supply water temperature and the water flow rate can be acquired in real time through a data acquisition system or a control system of a HVAC system, and the second reference heat exchange amount Q can be calculated using formula (2):

[0124] Q=(c·m water ·(T back -T cool )) (2)

[0125] Where c is the specific heat capacity of water, T back is the actual return water temperature, T back is the actual water supply temperature, m water For water flow.

[0126] S4013: Determine the larger value of the first reference heat exchange amount and the second reference heat exchange amount as the unit thermal load of the current cycle.

[0127] In order to effectively solve the problem of uneven return water mixing in the water collector, which may lead to large deviations in return water temperature measurement, the larger value of the first reference heat exchange amount and the second reference heat exchange amount can be selected as the thermal load of the unit, thereby effectively ensuring that the system can still operate normally under the highest load, avoiding the situation where the system cannot meet the demand or malfunctions due to a sudden increase in load, so as to ensure stable system operation.

[0128] like Figure 6 As shown, in some embodiments, in S101, obtaining the first load demand of the current cycle may include the following steps: S601-S603.

[0129] S601, obtaining a return air ratio of a HVAC system, an indoor ambient air enthalpy value of a power supply area, and an outdoor ambient air enthalpy value.

[0130] The return air ratio refers to the ratio of the return air volume to the total supply air volume in the HVAC system, and is used to describe the proportion of return air in the indoor air. Specifically, the return air ratio = indoor return air mass flow / total mass flow.

[0131] As a specific example, the indoor ambient air enthalpy value h of the energy supply area can be calculated by formula (3): room :

[0132] [h room ,d room ]=f(T room ,RH room ) (3)

[0133] Where, T room is the indoor temperature, RH room is the indoor relative humidity, h room is the enthalpy of indoor ambient air, d room is the indoor air humidity content, and f is the conversion function of the wet air parameters.

[0134] Based on this, the specific calculation process of the above formula (3) is as follows:

[0135] T=273.15+T room (3a)

[0136]

[0137]

[0138] h room =(1.01·T room +10 -3 ·d room ·(2501+1.84·T room ))·10 3 (3d)

[0139] In one example, assuming that the indoor temperature T room =a, RH room =b.

[0140] First, T room =a is substituted into formula (3a) to calculate the value of T. Next, T = a + 273.15, RH room = b into formula (3b) to calculate the value of Pq. Then, substitute the calculated value of Pq into formula (3c) to obtain d room Finally, the calculated d room The value of T room =a Substitute into formula (3d) and calculate h room As a specific example, the outdoor ambient air enthalpy value h of the energy supply area can be calculated by formula (4): env :

[0141] [h env ,d env ]=f(T env ,RH env ) (4)

[0142] Where, T env is the outdoor ambient temperature, RH env is the relative humidity of the outdoor environment, d env is the humidity content of the outdoor environment, and f is the conversion function of the wet air parameters.

[0143] S602: Determine the mixed air enthalpy value according to the return air ratio, the indoor ambient air enthalpy value and the outdoor ambient air enthalpy value.

[0144] As a specific example, the mixed air enthalpy value h can be calculated by formula (5): mix :

[0145] h mix =α·h env +(1-α)·h room (5)

[0146] In the formula, h mix is the mixed air enthalpy, α is the return air ratio, h room is the enthalpy of indoor ambient air, h env is the enthalpy of outdoor ambient air.

[0147] S603, when it is determined that the HVAC system is in dehumidification mode, determine the first load demand according to the enthalpy value of the dew point temperature of the humid air at the indoor temperature and humidity setting value when it reaches the saturated state, the mass flow rate of the air entering the air conditioning system, and the mixed air enthalpy value.

[0148] As a specific example, the first load demand E of the current cycle can be determined by formula (6):

[0149] E=m air ·(h mix -h dew ) (6)

[0150] In the formula, h dew is the enthalpy value of the humid air corresponding to the indoor temperature and humidity setting value when the dew point temperature reaches the saturated state, h dew The corresponding relative humidity is 100%, m air is the mass flow rate of air entering the air conditioning system, h mix is the enthalpy of mixed air.

[0151] Combining the enthalpy value of the dew point temperature of the humid air at the indoor temperature and humidity set value when it reaches the saturated state, the mass flow rate of air entering the air-conditioning system, and the mixed air enthalpy value can improve the accuracy of calculating the first load demand in the dehumidification mode, allowing the HVAC system to respond more quickly to changes in the indoor environment.

[0152] The HVAC system in the energy supply area often uses a fixed water temperature setting, that is, the water supply temperature (hot water outlet temperature or chilled water outlet temperature) is set to a fixed value. This setting method often leads to a mismatch between the load demand of the energy supply area and the unit load, deviating from the optimal operating conditions of the HVAC system. At the same time, the water supply temperature set by manual experience has a large system lag and cannot respond to the dynamic changes of the load in the energy supply area in real time.

[0153] Based on the above reasons, Figure 7 As shown, in some embodiments, in S1021, obtaining the set temperature of the unit in the current cycle may include the following steps: S701-S705.

[0154] S701, obtaining a return air ratio of a HVAC system, an indoor air humidity content of a power supply area, an outdoor air humidity content, an indoor ambient air enthalpy value, and an outdoor ambient air enthalpy value.

[0155] S702: Determine the mixed air enthalpy value according to the return air ratio, the indoor ambient air enthalpy value and the outdoor ambient air enthalpy value.

[0156] In some embodiments, the mixed air enthalpy value can be determined by the above formula (5), which will not be described in detail here.

[0157] S703: Determine the mixed air humidity content according to the return air ratio, the indoor air humidity content and the outdoor air humidity content.

[0158] As a specific example, the indoor air humidity d can be determined by formula (3): room , determine the outdoor environment humidity d by formula (4) env The mixed air humidity d can be determined by formula (7) mix :

[0159] d mix =α·d env +(1-α)·d room (7)

[0160] Where, d env is the enthalpy of outdoor ambient air, d room is the indoor air humidity content, and α is the return air ratio.

[0161] S704: Determine the terminal air inlet temperature according to a conversion function of the mixed air moisture content, the mixed air enthalpy value and the first wet air parameter.

[0162] As a specific example, the terminal air inlet temperature T can be determined by formula (8): mix :

[0163] T mix =g(h mix ,d mix ) (8)

[0164] Where g is the conversion function of moist air parameters, h mix is the mixed air enthalpy, d mix It is the humidity content of mixed air.

[0165] In an example, the specific calculation process of the above formula (8) is as follows:

[0166]

[0167] S705, determining the set temperature of the unit according to the terminal air inlet temperature and the first load demand.

[0168] By adjusting the unit set temperature according to the terminal air inlet temperature and the first load demand, the system can control the indoor temperature more accurately, avoid over-cooling or heating, and thus save energy consumption.

[0169] As a specific example, the unit set temperature can be determined by formula (9):

[0170]

[0171] Where E is the first load demand, is the terminal air inlet temperature, G water is the chilled water flow rate, G air is the air flow rate, Q 0 is the load calibration quantity, is the inlet temperature calibration quantity, is the unit outlet water temperature calibration quantity, is the chilled water flow calibration quantity, The air flow calibration quantity.

[0172] It should be noted that the calibration part in the above formula (9) can be obtained through experimental measurement. Further, after the set temperature of the unit is obtained, it can be output to the control module of the unit through first-order trajectory planning to avoid sudden changes in the set temperature of the unit.

[0173] Next, the control method of the HVAC system of the present application will be further explained in combination with a specific implementation scenario.

[0174] In this embodiment, it is assumed that the summer cooling rate threshold is set to Y=0.03°C / min, the actual workload factor of the unit is β=0.85, and the return air ratio is α=0.15.

[0175] like Figure 8 As shown, from top to bottom are the outdoor temperature and humidity curve, indoor temperature and humidity curve, unit refrigeration temperature setting value and estimated load curve, system total energy consumption curve, and human comfort index curve. In the calculation method of the estimated load, the unit thermal load is determined as the first load demand of the current cycle in method A, and the second load demand of the previous cycle is determined as the first load demand of the current cycle in method B. Figure 8 It can be seen that the estimated load is updated when the steady-state assumption is reached. After the building load increases, the unit number module determines whether to add units.

[0176] Through actual building measurements, the algorithm can save energy by about 20% in an environment with a maximum outdoor temperature of 32°C in summer.

[0177] Based on the control method of the HVAC system provided in the above embodiment, the present application also provides a specific implementation of the control device of the HVAC system. Please refer to the following embodiment.

[0178] like Fig. 9 As shown, a control device 900 of a HVAC system provided in an embodiment of the present application may include:

[0179] The first acquisition module 901 is used to acquire the first load demand of the current cycle, the unit status information, and the number of first operating units in the previous cycle before the current cycle and closest to the current cycle;

[0180] A first determination module 902 is used to determine the unit demand of the current cycle according to the first load demand and the unit state information when it is determined that the number of the first operating units meets the first load demand and the HVAC system is in a steady state;

[0181] A second determination module 903 is used to determine the first number of operating units as the unit demand of the current cycle when it is determined that the first number of operating units meets the first load demand and the HVAC system is in a non-steady state;

[0182] The adjustment module 904 is used to adjust the operating units in the current cycle according to the unit demand.

[0183] The control device of the HVAC system provided in the embodiment of the present application can obtain the first load demand and unit status information of the current cycle in real time through the first acquisition module 901, and can adjust the unit demand according to the actual first load demand and unit status information through the first determination module 902 when the number of the first operating units meets the first load demand and the HVAC system runs smoothly, which helps to obtain a unit demand that is more suitable for the actual load demand. When the number of the first operating units meets the first load demand and the HVAC system runs unsteadily, the first operating unit number of the previous cycle is used as the operating unit of the current cycle through the second determination module 903, which helps to maintain the stability of the system and avoid frequent unit switching leading to unstable system operation. Further, the operating unit of the current cycle can be adjusted according to the unit demand through the adjustment module 904 to ensure that the HVAC system responds quickly to load changes, so that the HVAC system matches the actual demand more accurately, and solves the problem that the number of units cannot be flexibly adjusted in the traditional method. This dynamic adjustment of the number of units can increase the possibility of matching the number of operating units with the actual demand, and can effectively improve the operating efficiency of the HVAC system.

[0184] As an implementation of the present application, in order to more accurately determine whether the current operating state of the HVAC system and the number of units are sufficient to meet the load demand, the control device may further include:

[0185] The second acquisition module is used to obtain the unit temperature control information of the current cycle, the unit temperature control information includes the unit set temperature, the unit actual water supply temperature and the unit temperature change rate, and obtain the number of second operating units in the preset time period of the previous cycle;

[0186] The third determination module is used to determine that the HVAC system is in a steady state when the number of the second operating units is the same as the number of the first operating units and the unit temperature control information meets the first preset condition, and the first preset condition includes at least one of the following: the difference between the unit set temperature and the actual water supply temperature of the unit is less than the first preset threshold, and the unit temperature change rate is less than the second preset threshold.

[0187] As an implementation of the present application, in order to accurately determine whether the HVAC system is in a steady state, the control device may further include:

[0188] The third acquisition module is used to obtain the set temperature of the unit, the actual water supply temperature of the unit and the temperature change rate of the unit in the current cycle;

[0189] The fourth determination module is used to determine whether the first number of operating units meets the first load demand when the difference between the set temperature of the unit and the actual water supply temperature of the unit is greater than the third preset threshold and the temperature change rate of the unit is lower than the fourth preset threshold.

[0190] As an implementation of the present application, in order to reasonably configure the number of units and more effectively utilize energy, the control device may also include:

[0191] The fourth determination module is used to determine the unit demand of the current cycle according to the first load demand and the unit power of a single unit when it is determined that the number of the first operating units does not meet the first load demand.

[0192] As an implementation of the present application, in order to more accurately predict and meet the current load characteristics and demand changes in the energy supply area, the first acquisition module 901 may include:

[0193] The first acquisition submodule is used to obtain the second load demand of the previous cycle, the thermal load of the unit in the current cycle, and the environmental information of the energy supply area;

[0194] A first determination submodule is used to determine the unit thermal load as the first load demand of the current cycle when it is determined that the HVAC system is in a non-dehumidification mode and in a steady state;

[0195] The second determination submodule is used to determine the second load demand as the first load demand of the current cycle when it is determined that the HVAC system is in a non-dehumidification mode and a non-steady state.

[0196] As an implementation of the present application, in order to effectively solve the problem of uneven mixing of return water in the water collector, the first acquisition submodule may specifically include:

[0197] An acquisition unit, used to acquire an actual return water temperature, an actual supply water temperature, a water flow rate of the running unit in the current cycle, and a first reference heat exchange amount of the running unit determined by a sensor installed on the running unit;

[0198] A first determining unit, configured to determine a second reference heat exchange amount according to an actual return water temperature, an actual supply water temperature and a water flow rate;

[0199] The second determining unit is used to determine the larger value of the first reference heat exchange amount and the second reference heat exchange amount as the unit thermal load of the current cycle.

[0200] As an implementation of the present application, in order to respond to changes in the indoor environment more quickly, the first acquisition module 901 may include:

[0201] The second acquisition submodule is used to obtain the return air ratio of the HVAC system, the indoor ambient air enthalpy value of the energy supply area, and the outdoor ambient air enthalpy value;

[0202] A third determination submodule is used to determine the mixed air enthalpy value according to the return air ratio, the indoor ambient air enthalpy value and the outdoor ambient air enthalpy value;

[0203] The fourth determination submodule is used to determine the first load demand E of the current cycle according to the following expression when it is determined that the HVAC system is in the dehumidification mode:

[0204] E=m air ·(h mix -h dew )

[0205] In the formula, h dew is the enthalpy value of the humid air at the dew point temperature corresponding to the indoor temperature and humidity setting value when it reaches the saturated state, m air is the mass flow rate of air entering the air conditioning system, h mix is the enthalpy of mixed air.

[0206] As an implementation of the present application, in order to more accurately control the indoor temperature and avoid excessive cooling or heating, thereby saving energy consumption, the second acquisition module may include:

[0207] The third acquisition submodule is used to obtain the return air ratio of the HVAC system, the indoor air humidity content of the energy supply area, the outdoor air humidity content, the indoor ambient air enthalpy value and the outdoor ambient air enthalpy value;

[0208] A fifth determination submodule, used to determine the mixed air enthalpy value according to the return air ratio, the indoor ambient air enthalpy value and the outdoor ambient air enthalpy value;

[0209] A sixth determination submodule, for determining the mixed air humidity content according to the return air ratio, the indoor air humidity content and the outdoor air humidity content;

[0210] a seventh determination submodule, for determining the terminal air inlet temperature according to a conversion function of the mixed air moisture content, the mixed air enthalpy value and the first wet air parameter;

[0211] The eighth determination submodule is used to determine the set temperature of the unit according to the terminal air inlet temperature and the first load demand.

[0212] As an implementation of the present application, the eighth determination submodule is used to solve the set temperature of the unit according to the following expression:

[0213]

[0214] Where E is the first load demand, is the terminal air inlet temperature, G water is the chilled water flow rate, G air is the air flow rate, Q 0 is the load calibration quantity, is the inlet temperature calibration quantity, is the unit outlet water temperature calibration quantity, is the chilled water flow calibration quantity, The air flow calibration quantity.

[0215] Based on the same inventive concept, an embodiment of the present application also provides an electronic device.

[0216] Fig.10 A schematic diagram of the hardware structure of an electronic device provided in an embodiment of the present application is shown.

[0217] The electronic device may include a processor 1001 and a memory 1002 storing computer program instructions.

[0218] Specifically, the processor 1001 may include a central processing unit (CPU), or an application specific integrated circuit (ASIC), or may be configured to implement one or more integrated circuits of the embodiments of the present application.

[0219] The memory 1002 may include a large capacity memory for data or instructions. By way of example and not limitation, the memory 1002 may include a hard disk drive (HDD), a floppy disk drive, a flash memory, an optical disk, a magneto-optical disk, a magnetic tape, or a universal serial bus (USB) drive or a combination of two or more of these. In appropriate cases, the memory 1002 may include a removable or non-removable (or fixed) medium. In appropriate cases, the memory 1002 may be inside or outside the integrated gateway disaster recovery device. In a specific embodiment, the memory 1002 is a non-volatile solid-state memory.

[0220] The memory 1002 may include a read-only memory (ROM), a random access memory (RAM), a magnetic disk storage media device, an optical storage media device, a flash memory device, an electrical, optical or other physical / tangible memory storage device. Thus, typically, the memory 1002 includes one or more tangible (non-transitory) computer-readable storage media (e.g., a memory device) encoded with software including computer-executable instructions, and when the software is executed (e.g., by one or more processors), it is operable to perform the operations described with reference to the method according to an aspect of the present disclosure.

[0221] The processor 1001 implements any one of the control methods for the HVAC system in the above embodiments by reading and executing computer program instructions stored in the memory 1002 .

[0222] In one example, the electronic device may further include a communication interface 1003 and a bus 1010. Fig.10 As shown, the processor 1001, the memory 1002, and the communication interface 1003 are connected via a bus 1010 and communicate with each other.

[0223] The communication interface 1003 is mainly used to implement communication between various modules, devices, units and / or equipment in the embodiments of the present application.

[0224] Bus 1010 includes hardware, software or both, and the parts of electronic equipment are coupled to each other.For example, but not limitation, bus may include accelerated graphics port (AGP) or other graphics bus, enhanced industrial standard architecture (EISA) bus, front side bus (FSB), hypertransport (HT) interconnection, industrial standard architecture (ISA) bus, infinite bandwidth interconnection, low pin count (LPC) bus, memory bus, micro channel architecture (MCA) bus, peripheral component interconnection (PCI) bus, PCI-Express (PCI-X) bus, serial advanced technology attachment (SATA) bus, video electronics standard association local (VLB) bus or other suitable bus or two or more of these combinations. In appropriate cases, bus 1010 may include one or more buses. Although the present application embodiment describes and shows a specific bus, the application considers any suitable bus or interconnection.

[0225] The electronic device can execute the control method of the HVAC system in the embodiment of the present application, thereby realizing the combination Figure 1 and Fig. 9 A method and apparatus for controlling a heating, ventilation and air conditioning system is described.

[0226] In addition, in combination with the control method of the HVAC system in the above embodiments, the embodiment of the present application can provide a computer storage medium for implementation. The computer storage medium stores computer program instructions; when the computer program instructions are executed by the processor, any one of the control methods of the HVAC system in the above embodiments is implemented.

[0227] In addition, the present application also provides a computer program product, which includes a computer program. When the computer program is processed and executed, the aforementioned control method of the HVAC system is implemented.

[0228] It should be clear that the present application is not limited to the specific configuration and processing described above and shown in the figures. For the sake of simplicity, a detailed description of the known method is omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of the present application is not limited to the specific steps described and shown, and those skilled in the art can make various changes, modifications and additions, or change the order between the steps after understanding the spirit of the present application.

[0229] The functional blocks shown in the above-described block diagram can be implemented as hardware, software, firmware or a combination thereof. When implemented in hardware, it can be, for example, an electronic circuit, an application specific integrated circuit (ASIC), appropriate firmware, a plug-in, a function card, etc. When implemented in software, the elements of the present application are programs or code segments that are used to perform the required tasks. The program or code segment can be stored in a machine-readable medium, or transmitted on a transmission medium or a communication link by a data signal carried in a carrier wave. "Machine-readable medium" can include any medium capable of storing or transmitting information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, ROM, flash memory, erasable ROM (EROM), floppy disks, CD-ROMs, optical disks, hard disks, optical fiber media, radio frequency (RF) links, etc. The code segment can be downloaded via a computer network such as the Internet, an intranet, etc.

[0230] It should also be noted that the exemplary embodiments mentioned in this application describe some methods or systems based on a series of steps or devices. However, this application is not limited to the order of the above steps, that is, the steps can be performed in the order mentioned in the embodiment, or in a different order from the embodiment, or several steps can be performed simultaneously.

[0231] Aspects of the present disclosure are described above with reference to the flowchart and / or block diagram of the method, device (system) and computer program product according to the embodiment of the present disclosure. It should be understood that each box in the flowchart and / or block diagram and the combination of each box in the flowchart and / or block diagram can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device to produce a machine so that these instructions executed by the processor of the computer or other programmable data processing device enable the implementation of the function / action specified in one or more boxes of the flowchart and / or block diagram. Such a processor can be, but is not limited to, a general-purpose processor, a special-purpose processor, a special application processor, or a field programmable logic circuit. It can also be understood that each box in the block diagram and / or flowchart and the combination of boxes in the block diagram and / or flowchart can also be implemented by dedicated hardware that performs a specified function or action, or can be implemented by a combination of dedicated hardware and computer instructions.

[0232] The above is only a specific implementation of the present application. Those skilled in the art can clearly understand that for the convenience and simplicity of description, the specific working processes of the systems, modules and units described above can refer to the corresponding processes in the aforementioned method embodiments, and will not be repeated here. It should be understood that the protection scope of the present application is not limited to this. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed in this application, and these modifications or replacements should be included in the protection scope of this application.

Claims

1. A method for controlling a heating, ventilation and air conditioning system, characterized in that: The method comprises: Obtaining the first load demand of the current cycle, unit status information, and the number of first operating units in the previous cycle that is before the current cycle and closest to the current cycle; When it is determined that the first number of operating units meets the first load demand and the HVAC system is in a steady state, determining the unit demand of the current cycle according to the first load demand and the unit status information; When it is determined that the first number of operating units meets the first load demand and the HVAC system is in a non-steady state, determining the first number of operating units as the unit demand of the current cycle; The operating units of the current cycle are adjusted according to the unit demand.

2. The method according to claim 1, characterized in that Before determining that the first number of operating units meets the first load demand and the HVAC system is in a steady state, the method further includes: Acquire the unit temperature control information of the current cycle, wherein the unit temperature control information includes the unit set temperature, the unit actual water supply temperature and the unit temperature change rate; Obtaining the number of second operating units within the preset time period to which the previous cycle belongs; When the number of the second operating units is the same as the number of the first operating units and the unit temperature control information satisfies a first preset condition, it is determined that the HVAC system is in a steady state, and the first preset condition includes at least one of the following: the difference between the unit set temperature and the actual water supply temperature of the unit is less than a first preset threshold, and the unit temperature change rate is less than a second preset threshold.

3. The method according to claim 1, characterized in that Before determining that the first number of operating units meets the first load demand and the HVAC system is in a steady state, the method further includes: Obtain the unit set temperature, unit actual water supply temperature and unit temperature change rate of the current cycle; When the difference between the set temperature of the unit and the actual water supply temperature of the unit is greater than a third preset threshold and the temperature change rate of the unit is lower than a fourth preset threshold, it is determined that the first number of operating units meets the first load demand.

4. The method according to claim 1, characterized in that The method further comprises: When it is determined that the first number of operating units does not meet the first load demand, the unit demand of the current cycle is determined according to the first load demand and the unit power of a single unit.

5. The method according to any one of claims 1 to 4, characterized in that: The obtaining of the first load demand of the current cycle includes: Obtaining the second load demand of the previous cycle, the thermal load of the unit in the current cycle, and environmental information of the energy supply area; When it is determined that the HVAC system is in a non-dehumidification mode and in a steady state, the thermal load of the unit is determined as a first load demand of the current cycle; When it is determined that the HVAC system is in a non-dehumidification mode and a non-steady state, the second load demand is determined as the first load demand of the current cycle.

6. The method according to claim 5, characterized in that The obtaining of the unit thermal load of the current cycle includes: Acquire the actual return water temperature, the actual supply water temperature, the water flow rate of the running unit in the current cycle, and the first reference heat exchange amount of the running unit determined by a sensor installed on the running unit; Determine a second reference heat exchange amount according to the actual return water temperature, the actual supply water temperature and the water flow rate; The larger value of the first reference heat exchange amount and the second reference heat exchange amount is determined as the thermal load of the unit in the current cycle.

7. The method according to any one of claims 1 to 4, characterized in that: The obtaining of the first load demand of the current cycle includes: Obtaining the return air ratio of the HVAC system, the indoor ambient air enthalpy value of the energy supply area, and the outdoor ambient air enthalpy value; Determining a mixed air enthalpy value according to the return air ratio, the indoor ambient air enthalpy value and the outdoor ambient air enthalpy value; When it is determined that the HVAC system is in the dehumidification mode, the first load demand E of the current cycle is determined according to the following expression: E=m air ·(h mix -h dew ) In the formula, h dew is the enthalpy value of the humid air at the dew point temperature corresponding to the indoor temperature and humidity setting value when it reaches the saturated state, m air is the mass flow rate of air entering the air conditioning system, h mix is the enthalpy of mixed air.

8. The method according to claim 2, characterized in that: The obtaining of the set temperature of the unit in the current cycle includes: Obtaining the return air ratio of the HVAC system, the indoor air humidity content of the energy supply area, the outdoor air humidity content, the indoor ambient air enthalpy value and the outdoor ambient air enthalpy value; Determining a mixed air enthalpy value according to the return air ratio, the indoor ambient air enthalpy value and the outdoor ambient air enthalpy value; Determining the mixed air humidity content according to the return air ratio, the indoor air humidity content and the outdoor air humidity content; determining a terminal air inlet temperature according to a conversion function of the mixed air moisture content, the mixed air enthalpy value and a first wet air parameter; The unit set temperature is determined according to the terminal air inlet temperature and the first load demand.

9. The method according to claim 8, characterized in that The determining of the unit set temperature according to the terminal air inlet temperature and the first load demand comprises: Solve the unit set temperature T according to the following expression inwater : Where E is the first load demand, T inair is the terminal air inlet temperature, G water is the chilled water flow rate, G air is the air flow rate, Q0 is the load calibration quantity, T 0air is the inlet temperature calibration quantity, T 0water is the unit outlet water temperature calibration quantity, G 0water is the chilled water flow calibration quantity, G 0air The air flow calibration quantity.

10. A control device for a heating, ventilation and air conditioning system, characterized in that: The device comprises: A first acquisition module is used to acquire a first load demand of a current cycle, unit status information, and the number of first operating units in a previous cycle that is before the current cycle and closest to the current cycle; A first determination module, configured to determine the unit demand of the current cycle according to the first load demand and the unit state information when it is determined that the first number of operating units meets the first load demand and the HVAC system is in a steady state; a second determining module, configured to determine the first number of operating units as the unit demand of the current cycle when it is determined that the first number of operating units meets the first load demand and the HVAC system is in a non-steady state; The adjustment module is used to adjust the operating units in the current cycle according to the demand of the units.

Images