Heat pump group control optimization method and device for regional cold source system

Abstract

The present invention provides a method and device for optimizing heat pump group control of a regional cold source system. The regional cold source system includes a plurality of energy subsystems, and the energy subsystem includes a heat pump unit. The method includes: constructing an optimization model for heat pump group control of the regional cold source system based on the operation load rate of the heat pump units of the energy subsystems; solving and optimizing the optimization model for heat pump group control of the regional cold source system based on a numerically stable dual solution method to obtain the optimized operation load rate of the heat pump units of the energy subsystems; determining the optimized chilled water outlet temperature of the heat pump units of the energy subsystems based on the optimized operation load rate of the heat pump units of the energy subsystems. The energy utilization efficiency and operation stability of the system are improved.

Description

Technical Field

[0001] The invention relates to the field of regional cold source systems, and in particular to a method and a device for optimizing group control of heat pumps in regional cold source systems. Background Art

[0002] In the field of construction, the regional cooling system has attracted extensive attention and application as an efficient way of energy utilization. The system generates cold sources in a centralized manner and transmits cold energy to each user end through a transmission and distribution pipeline network, thus realizing centralized cooling of multiple buildings or regions. Compared with the traditional decentralized cooling method, the regional cooling system has significant advantages such as high energy utilization efficiency, convenient equipment maintenance and management, and low environmental impact.

[0003] In the process of realizing the concept of the present invention, it was found that although the regional cold source system has the above-mentioned significant advantages, the regional cold source system still has problems of low energy efficiency and insufficient control accuracy during operation. Summary of the invention

[0004] In view of this, the present invention provides a method and device for optimizing heat pump group control in a regional cold source system.

[0005] One aspect of the present invention provides a method for optimizing heat pump group control of a regional cold source system, wherein the regional cold source system includes multiple energy subsystems, and the energy subsystems include heat pump units; the method includes: constructing an optimization model for heat pump group control of the regional cold source system based on the operating load rates of the heat pump units of each energy subsystem; solving and optimizing the optimization model for heat pump group control of the regional cold source system based on a numerically stable dual solution method to obtain the optimized operating load rates of the heat pump units of each energy subsystem; and determining the optimized chilled water outlet temperature of the heat pump units of each energy subsystem based on the optimized operating load rates of the heat pump units of each energy subsystem.

[0006] According to an embodiment of the present invention, based on the operating load rate of the heat pump units of each energy subsystem, a regional cold source system heat pump group control optimization model is constructed, including: based on the chilled water demand parameter of the regional cold source system, the operating load rate of the heat pump units of each energy subsystem is subjected to equation constraints to obtain a first constraint condition; based on the safe operating condition of the chilled water outlet temperature, the upper limit value and the lower limit value of the operating load rate of the heat pump units of each energy subsystem are constrained to obtain a second constraint condition; based on the operating load rate and cooling power of the heat pump units of each energy subsystem, an optimization objective function is constructed using a quadratic function; and the optimization objective function, the first constraint condition and the second constraint condition are determined as the regional cold source system heat pump group control optimization model.

[0007] According to an embodiment of the present invention, the chilled water demand parameters of the regional cold source system include: chilled water return temperature and chilled water supply temperature; based on the chilled water demand parameters of the regional cold source system, an equation constraint is performed on the operating load rate of the heat pump units of each energy subsystem to obtain a first constraint condition, including: obtaining a temperature difference based on the difference between the chilled water return temperature and the chilled water supply temperature; and an equation constraint is performed based on an indirect correlation between the temperature difference and the operating load rate of the heat pump units of each energy subsystem to obtain the first constraint condition.

[0008] According to an embodiment of the present invention, the first constraint condition includes the following formula (1):

[0009] (1)

[0010] in, represents the number of energy subsystems of the district cooling system, Indicates The mixed water load factor of each energy subsystem is Indicates The operating load rate of the heat pump unit of each energy subsystem is Indicates the chilled water return temperature. Indicates the chilled water supply temperature;

[0011] No. Mixed water load factor for each energy subsystem Including formula (2):

[0012] (2)

[0013] in, Indicates The number of heat pump units in operation in each energy subsystem, Indicates Chilled water flow rate of heat pump unit in each energy subsystem, unit , Indicates the total chilled water flow rate of the regional cold source system, in units , Indicates The energy conservation load factor of the heat pump unit of the energy subsystem is The energy conservation load factor of the heat pump unit of the energy subsystem is based on the The rated cooling capacity of the heat pump unit of the energy subsystem and the The chilled water operating flow rate of the heat pump unit of each energy subsystem is determined.

[0014] According to an embodiment of the present invention, the second constraint condition includes an upper limit value constraint condition and a lower limit value constraint condition;

[0015] The upper limit constraint condition is as shown in formula (3):

[0016] (3)

[0017] The lower limit constraint condition is as shown in formula (4):

[0018] (4)

[0019] in, Indicates The lower limit of the operating load rate of the heat pump unit of each energy subsystem is Indicates The upper limit of the operating load rate of the heat pump unit of each energy subsystem is Indicates The maximum chilled water outlet temperature of the heat pump unit of each energy subsystem, in °C, Indicates The minimum chilled water outlet temperature of the heat pump unit of each energy subsystem, in °C, Indicates The energy conservation load factor of the heat pump unit of each energy subsystem is: Indicates The minimum operating load rate of the heat pump unit of each energy subsystem, Indicates The maximum operating load rate of the heat pump unit of each energy subsystem.

[0020] According to an embodiment of the present invention, based on the operating load rate and refrigeration power of the heat pump units of each energy subsystem, an optimization objective function is constructed using a quadratic function, including: for the heat pump units of each energy subsystem: based on the chilled water outlet temperature, cooling water outlet temperature and operating load rate of the heat pump units, a heat pump unit model of the energy subsystem is constructed; based on the known terms in the heat pump unit model and the principle of energy conservation, the heat pump unit model is converted into a model associated with refrigeration power and operating load rate; based on the relationship between the parameters of the model associated with refrigeration power and operating load rate, the energy conservation load rate coefficient of the heat pump unit and the rated refrigeration power of the heat pump unit, the quadratic Hessian matrix of the quadratic function is determined; based on the parameters of the model associated with refrigeration power and operating load rate, the energy conservation load rate coefficient of the heat pump unit, the rated refrigeration power of the heat pump unit, the cooling water outlet temperature and the chilled water return temperature, the linear term vector of the quadratic function is determined; and based on the quadratic Hessian matrix and the linear term vector, an optimization objective function for the operating load rate of the heat pump unit is constructed.

[0021] According to an embodiment of the present invention, the regional cold source system heat pump group control optimization model includes the following formula (5):

[0022] (5)

[0023] in, Indicates The objective function of the heat pump group control optimization model for the regional cold source system is the independent variable. Represents the operating load rate vector of the heat pump units of each energy subsystem, with dimension , represents the number of energy subsystems of the district cooling system, , Represents the quadratic Hessian matrix, dimension , , represents the second order Hessian matrix diagonal elements, , Indicates The rated cooling power of the heat pump unit of each energy subsystem is represents a linear term vector, dimension , , The first term vector elements, , Indicates the chilled water return temperature. Indicates The cooling water outlet temperature of the heat pump unit of each energy subsystem is Indicates the chilled water supply temperature; , …, Sequentially indicates The first to ninth model coefficients in the model of the energy subsystem related to cooling power and operating load rate are: The left-hand matrix representing the equality constraint, dimension , , Indicates The mixed water load factor of each energy subsystem is The right-hand side vector representing the equality constraint, dimension , , Indicates the chilled water supply temperature. Represents the lower limit vector of the operating load rate of the heat pump unit of each energy subsystem, with dimension , , Indicates The lower limit of the operating load rate of the heat pump unit of each energy subsystem is Represents the upper limit vector of the operating load rate of the heat pump units of each energy subsystem, with dimension , , Indicates The upper limit of the operating load rate of the heat pump unit of each energy subsystem.

[0024] According to an embodiment of the present invention, based on the optimized operating load rate of the heat pump units of each energy subsystem, the optimized chilled water outlet temperature of the heat pump units of each energy subsystem is determined, including: for the heat pump units of each energy subsystem: obtaining the loss temperature difference according to the product of the optimized operating load rate of the heat pump unit and the energy conservation load rate coefficient of the heat pump unit; and obtaining the optimized chilled water outlet temperature according to the difference between the chilled water return temperature and the loss temperature difference.

[0025] According to an embodiment of the present invention, optimizing the chilled water outlet temperature includes the following formula (6):

[0026] (6)

[0027] in, Indicates The optimal chilled water outlet temperature of the heat pump unit of each energy subsystem, Indicates the chilled water return temperature. Indicates The energy conservation load factor of the heat pump unit of each energy subsystem is: Indicates The optimized operating load rate of the heat pump unit of each energy subsystem.

[0028] Another aspect of the present invention provides a regional cold source system heat pump group control optimization device, the regional cold source system includes multiple energy subsystems, the energy subsystems include heat pump units; the regional cold source system heat pump group control optimization device includes: a construction module, used to construct a regional cold source system heat pump group control optimization model based on the operating load rate of each heat pump unit in the energy subsystem; an optimization module, used to solve and optimize the regional cold source system heat pump group control optimization model based on a numerically stable dual solution method to obtain the optimized operating load rate of each heat pump unit in the energy subsystem; and a determination module, used to determine the optimized chilled water outlet temperature of each heat pump unit in the energy subsystem based on the optimized operating load rate of each heat pump unit in the energy subsystem.

[0029] According to the embodiment of the present invention, since the regional cold source system heat pump group control optimization model is constructed based on the operating load rate of the heat pump units of each energy subsystem, and then the optimization is solved based on the numerically stable dual solution method, it is possible to accurately calculate and optimize the operating state of the heat pump units of each energy subsystem, so that the regional cold source system can achieve better operation under different load conditions and improve energy utilization efficiency. In addition, the optimized chilled water outlet temperature is indirectly determined based on the optimized operating load rate to ensure that the chilled water outlet temperature is always within the safe working range, avoiding system instability caused by temperature fluctuations, and improving the safety and reliability of the regional cold source system. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The above and other objects, features and advantages of the present invention will become more apparent through the following description of the embodiments of the present invention with reference to the accompanying drawings.

[0031] Figure 1 A flow chart of a method for optimizing heat pump group control in a regional cold source system according to an embodiment of the present invention is shown.

[0032] Figure 2 A flow chart for constructing a heat pump group control optimization model for a regional cold source system according to an embodiment of the present invention is shown.

[0033] Figure 3 A flowchart for constructing an optimization objective function for a heat pump unit of each energy subsystem according to an embodiment of the present invention is shown.

[0034] Figure 4 A block diagram of a heat pump group control optimization device for a regional cold source system according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0035] Below, embodiments of the present invention will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the present invention. In the following detailed description, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of embodiments of the present invention. However, it is apparent that one or more embodiments may also be implemented without these specific details. In addition, in the following description, descriptions of known structures and technologies are omitted to avoid unnecessary confusion of concepts of the present invention.

[0036] The terms used herein are only for describing specific embodiments and are not intended to limit the present invention. The terms "comprise", "include", etc. used herein indicate the existence of features, steps, operations and / or components, but do not exclude the existence or addition of one or more other features, steps, operations or components.

[0037] All terms (including technical and scientific terms) used herein have the meanings commonly understood by those skilled in the art unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification and should not be interpreted in an idealized or overly rigid manner.

[0038] When using expressions such as "at least one of A, B, and C, etc.", they should generally be interpreted according to the meaning of the expression commonly understood by those skilled in the art (for example, "a system having at least one of A, B, and C" should include but is not limited to a system having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, C, etc.).

[0039] In the process of realizing the concept of the present invention, it is found that although the regional cold source system has the above-mentioned significant advantages, the regional cold source system still has problems of low energy efficiency and insufficient control accuracy during operation. For example, it is difficult for the traditional regional cold source system to accurately adjust the operating load rate of the heat pump unit of each energy subsystem, resulting in excessive energy consumption or unstable operation when the system is running under different load conditions. In addition, the outlet water temperature of the chilled water is prone to fluctuations, making it difficult to ensure that the system operates within a safe and efficient temperature range.

[0040] Based on this, an embodiment of the present invention provides a method for optimizing heat pump group control of a regional cold source system, wherein the regional cold source system includes multiple energy subsystems, and the energy subsystems include heat pump units; the method includes: constructing an optimization model for heat pump group control of the regional cold source system based on the operating load rates of the heat pump units of each energy subsystem; solving and optimizing the optimization model for heat pump group control of the regional cold source system based on a numerically stable dual solution method to obtain the optimized operating load rates of the heat pump units of each energy subsystem; and determining the optimized chilled water outlet temperature of the heat pump units of each energy subsystem based on the optimized operating load rates of the heat pump units of each energy subsystem.

[0041] The following will be passed Figure 1~Figure 3 The heat pump group control optimization method of the regional cold source system according to the embodiment of the present invention is described in detail.

[0042] Figure 1 A flow chart of a method for optimizing heat pump group control in a regional cold source system according to an embodiment of the present invention is shown.

[0043] The regional cooling source system includes multiple energy subsystems, and the energy subsystem includes a heat pump unit.

[0044] like Figure 1 As shown, the regional cold source system heat pump group control optimization method includes operations S110~S130.

[0045] In operation S110, a heat pump group control optimization model for the regional cold source system is constructed based on the operating load rates of the heat pump units of the energy subsystems.

[0046] In operation S120, based on a numerically stable dual solution method, the heat pump group control optimization model of the regional cold source system is solved and optimized to obtain the optimized operating load rate of the heat pump units of each energy subsystem.

[0047] In operation S130, based on the optimized operation load rate of the heat pump units of the energy subsystems, the optimized chilled water outlet temperatures of the heat pump units of the energy subsystems are determined.

[0048] According to an embodiment of the present invention, a heat pump group control optimization model for a regional cold source system is used to perform group control optimization on the operating load rates of the heat pump units of the multiple energy subsystems of the regional cold source system.

[0049] According to an embodiment of the present invention, the operating load rate can be used as an indicator to indicate the relationship between the actual load of a heat pump unit or an energy subsystem and its maximum load within a certain period of time. For a heat pump unit, the operating load rate can be used to reflect the utilization rate of the heat pump unit, and for an energy subsystem, the operating load rate can be used to reflect the operating status of the energy subsystem.

[0050] According to the embodiment of the present invention, the numerically stable dual solution method is not specifically limited in this embodiment.

[0051] According to an embodiment of the present invention, the ratio between the chilled water return and outlet water temperature difference and the operating load rate can be determined based on the linear relationship between the operating load rate and the chilled water return and outlet water temperature difference, and the optimized operating load rate of the heat pump units of each energy subsystem is multiplied by the ratio to obtain the optimized chilled water return and outlet water temperature difference. Based on the difference between the chilled water return temperature and the optimized chilled water return and outlet water temperature difference, the optimized chilled water outlet temperature of the heat pump units of each energy subsystem is obtained.

[0052] According to the embodiment of the present invention, since the regional cold source system heat pump group control optimization model is constructed based on the operating load rate of the heat pump units of each energy subsystem, and then the optimization is solved based on the numerically stable dual solution method, it is possible to accurately calculate and optimize the operating state of the heat pump units of each energy subsystem, so that the regional cold source system can achieve better operation under different load conditions and improve energy utilization efficiency. In addition, the optimized chilled water outlet temperature is indirectly determined based on the optimized operating load rate to ensure that the chilled water outlet temperature is always within the safe working range, avoiding system instability caused by temperature fluctuations, and improving the safety and reliability of the regional cold source system.

[0053] Figure 2 A flow chart for constructing a heat pump group control optimization model for a regional cold source system according to an embodiment of the present invention is shown.

[0054] According to an embodiment of the present invention, for the above Figure 1 In operation S110, based on the operating load rate of the heat pump units of the energy subsystems, a heat pump group control optimization model for the regional cold source system is constructed, which may include the following: Figure 2 Operations S211 to S214 are shown.

[0055] In operation S211, based on the chilled water demand parameter of the regional cold source system, an equality constraint is performed on the operating load rate of the heat pump units of the energy subsystems to obtain a first constraint condition.

[0056] In operation S212, based on the safe operating condition of the chilled water outlet temperature, the upper limit and lower limit of the operating load rate of the heat pump units of the energy subsystems are constrained to obtain a second constraint condition.

[0057] In operation S213, based on the operating load rate and cooling power of the heat pump units of the energy subsystems, an optimization objective function is constructed using a quadratic function.

[0058] In operation S214, the optimization objective function, the first constraint condition, and the second constraint condition are determined as a heat pump group control optimization model for a regional cold source system.

[0059] According to an embodiment of the present invention, the first constraint condition can be obtained by performing an equality constraint based on the linear relationship between the chilled water demand parameter of the regional cold source system and the operating load rate of the heat pump unit of each energy subsystem. The chilled water demand parameter of the regional cold source system may include but is not limited to: chilled water operating flow, chilled water return temperature and chilled water supply temperature.

[0060] According to an embodiment of the present invention, the chilled water outlet temperature safe operation condition may include an upper limit value of the chilled water outlet temperature safe operation and a lower limit value of the chilled water outlet temperature safe operation.

[0061] According to an embodiment of the present invention, the optimization objective of the optimization objective function is to minimize the operation load rate. The optimization objective function is used to analyze the relationship between the operation load rate and the refrigeration power.

[0062] According to the embodiment of the present invention, since the constructed regional cold source system heat pump group control optimization model belongs to a quadratic programming model, it is conducive to accurately solving the operating load rate of the heat pump units of each energy subsystem.

[0063] According to an embodiment of the present invention, the chilled water demand parameters of the regional cold source system may include: chilled water return temperature and chilled water supply temperature.

[0064] Regarding the above Figure 2In operation S211, based on the chilled water demand parameters of the regional cold source system, an equation constraint is performed on the operating load rate of the heat pump units of each energy subsystem to obtain a first constraint condition, which may include the following operations: obtaining a temperature difference based on the difference between the chilled water return temperature and the chilled water supply temperature; and performing an equation constraint based on an indirect correlation between the temperature difference and the operating load rate of the heat pump units of each energy subsystem to obtain the first constraint condition.

[0065] According to the embodiment of the present invention, since the difference between the chilled water return temperature and the chilled water supply temperature is a constant value, the indirect correlation between the temperature difference and the operation load rate can be regarded as a linear correlation.

[0066] According to an embodiment of the present invention, the first constraint condition may include the following formula (1):

[0067] (1)

[0068] in, represents the number of energy subsystems of the district cooling system, Indicates The mixed water load factor of each energy subsystem is Indicates The operating load rate of the heat pump unit of each energy subsystem is Indicates the chilled water return temperature. Indicates the chilled water supply temperature;

[0069] No. Mixed water load factor for each energy subsystem It can be included as shown in formula (2):

[0070] (2)

[0071] in, Indicates The number of heat pump units in operation in each energy subsystem, Indicates Chilled water flow rate of heat pump unit in each energy subsystem, unit , Indicates the total chilled water flow rate of the regional cold source system, in units , Indicates The energy conservation load factor of the heat pump unit of the energy subsystem is The energy conservation load factor of the heat pump unit of the energy subsystem is based on the The rated cooling capacity of the heat pump unit of the energy subsystem and the The chilled water operating flow rate of the heat pump unit of each energy subsystem is determined.

[0072] According to an embodiment of the present invention, the total flow rate of chilled water in the regional cold source system is It can be obtained based on the sum of the chilled water operating flows of the heat pump units of multiple energy subsystems.

[0073] According to the embodiments of the present invention, since the relationship between the rated cooling capacity, the chilled water operating flow rate and the energy conservation load rate coefficient is determined based on the principle of energy conservation, and then the mixed water load rate coefficient of the energy subsystem is determined, and the equation constraint is determined based on the linear relationship between the mixed water load rate coefficient of the energy subsystem and the temperature difference, it is possible to solve the problem of uneven load distribution in the traditional regional cold source system, ensure that each heat pump unit operates evenly under different load conditions, avoid overloading or no-load operation of some heat pump units, and extend the service life of the heat pump units.

[0074] According to an embodiment of the present invention, for the above Figure 2 In operation S212, the second constraint condition may include an upper limit constraint condition and a lower limit constraint condition.

[0075] The upper limit constraint condition may include the following formula (3):

[0076] (3)

[0077] The lower limit constraint condition may include the following formula (4):

[0078] (4)

[0079] in, Indicates The lower limit of the operating load rate of the heat pump unit of each energy subsystem is Indicates The upper limit of the operating load rate of the heat pump unit of each energy subsystem is Indicates The maximum chilled water outlet temperature of the heat pump unit of each energy subsystem, in °C, Indicates The minimum chilled water outlet temperature of the heat pump unit of each energy subsystem, in °C, Indicates The energy conservation load factor of the heat pump unit of each energy subsystem is: Indicates The minimum operating load rate of the heat pump unit of each energy subsystem, Indicates The maximum operating load rate of the heat pump unit of each energy subsystem.

[0080] According to an embodiment of the present invention, by limiting the lower and upper limits of the operating load rate of the heat pump unit of each energy subsystem, the heat pump unit can be operated near the optimal efficiency point, thereby improving energy utilization efficiency, reducing the number of starts and stops of the heat pump unit, reducing operating and maintenance costs, and reducing additional energy consumption caused by frequent starts and stops, avoiding the heat pump unit from operating under extreme loads, reducing the wear of the heat pump unit, and extending the service life of the heat pump unit.

[0081] Figure 3 A flowchart for constructing an optimization objective function for a heat pump unit of each energy subsystem according to an embodiment of the present invention is shown.

[0082] According to an embodiment of the present invention, for the above Figure 2 In operation S213, based on the operating load rate and cooling power of the heat pump units of the energy subsystems, the optimization objective function is constructed using the quadratic function, which may include: Figure 3 Operations S3131 to S3135 are shown.

[0083] In operation S3131, a heat pump unit model of the energy subsystem is constructed based on the chilled water outlet temperature, the cooling water outlet temperature and the operating load rate of the heat pump unit.

[0084] In operation S3132, based on known items in the heat pump unit model and the energy conservation principle, the heat pump unit model is converted into a model associated with cooling power and operating load rate.

[0085] In operation S3133, a quadratic Hessian matrix of the quadratic function is determined based on a relationship between parameters of a model relating cooling power to an operating load rate, an energy conservation load rate coefficient of the heat pump unit, and a rated cooling power of the heat pump unit.

[0086] In operation S3134, the linear term vector of the quadratic function is determined based on the relationship between the parameters of the model associating refrigeration power and operating load rate, the energy conservation load rate coefficient of the heat pump unit, the rated refrigeration power of the heat pump unit, the cooling water outlet temperature and the chilled water return temperature.

[0087] In operation S3135, an optimization objective function regarding the operation load rate of the heat pump unit is constructed based on the quadratic Hessian matrix and the linear vector.

[0088] It should be noted that operations S3131 to S3135 are operations performed on the heat pump unit of each energy subsystem.

[0089] According to an embodiment of the present invention, the regional cold source system heat pump group control optimization model may include the formula (5):

[0090] (5)

[0091] in, Indicates The objective function of the heat pump group control optimization model for the regional cold source system is the independent variable. Represents the operating load rate vector of the heat pump units of each energy subsystem, with dimension , represents the number of energy subsystems of the district cooling system, , Represents the quadratic Hessian matrix, dimension , , represents the second order Hessian matrix diagonal elements, , Indicates The rated cooling power of the heat pump unit of each energy subsystem is represents a linear term vector, dimension , , The first term vector elements, , Indicates the chilled water return temperature. Indicates The cooling water outlet temperature of the heat pump unit of each energy subsystem; , …, Sequentially indicates The first to ninth model coefficients in the model of the energy subsystem related to cooling power and operating load rate are: The left-hand matrix representing the equality constraint, dimension , , Indicates The mixed water load factor of each energy subsystem is The right-hand side vector representing the equality constraint, dimension , , Indicates the chilled water supply temperature. Represents the lower limit vector of the operating load rate of the heat pump unit of each energy subsystem, with dimension , , Indicates The lower limit of the operating load rate of the heat pump unit of each energy subsystem is Represents the upper limit vector of the operating load rate of the heat pump units of each energy subsystem, with dimension , , Indicates The upper limit of the operating load rate of the heat pump unit of each energy subsystem.

[0092] According to an embodiment of the present invention, a quadratic function is used to determine the optimization objective function, which can transform the group control optimization problem of heat pump units of multiple energy subsystems in a regional cold source system into a quadratic programming problem, which is conducive to accurately calculating the operating load rate of the heat pump units of each energy subsystem.

[0093] According to an embodiment of the present invention, for the above Figure 1 Operation S130 in the process determines the optimized chilled water outlet temperature of each heat pump unit of the energy subsystem based on the optimized operating load rate of each heat pump unit of the energy subsystem, and may also include the following operations: for the heat pump unit of each energy subsystem: obtaining the loss temperature difference according to the product of the optimized operating load rate of the heat pump unit and the energy conservation load rate coefficient of the heat pump unit; and obtaining the optimized chilled water outlet temperature according to the difference between the chilled water return temperature and the loss temperature difference.

[0094] According to an embodiment of the present invention, optimizing the chilled water outlet temperature includes the following formula (6):

[0095] (6)

[0096] in, Indicates The optimal chilled water outlet temperature of the heat pump unit of each energy subsystem, Indicates the chilled water return temperature. Indicates The energy conservation load factor of the heat pump unit of each energy subsystem is: Indicates The optimized operating load rate of the heat pump unit of each energy subsystem.

[0097] According to an embodiment of the present invention, the optimized chilled water outlet temperature is indirectly determined based on the optimized operating load rate to ensure that the chilled water outlet temperature is always within a safe operating range, thereby avoiding system instability due to temperature fluctuations and improving the safety and reliability of the regional cold source system.

[0098] According to an embodiment of the present invention, for the above Figure 3 In operation S3131, based on the chilled water outlet temperature, cooling water outlet temperature and operating load rate of the heat pump unit, a heat pump unit model of the energy subsystem is constructed. The heat pump unit model of the energy subsystem may include the following formula (7):

[0099] (7)

[0100] in, Indicates The cooling power of the heat pump unit of each energy subsystem, in kW, Indicates The rated cooling power of the heat pump unit of each energy subsystem, in kW, , …, Sequentially indicates The first to tenth model coefficients in the model of the energy subsystem that is associated with the cooling power and the operating load rate are the heat pump unit model. Indicates The chilled water outlet temperature of the heat pump unit of each energy subsystem, in °C, Indicates The cooling water outlet temperature of the heat pump unit of the energy subsystem.

[0101] According to an embodiment of the present invention, for the above Figure 3 The known items in the heat pump unit model in operation S3132 may include the cooling water outlet temperature of the heat pump unit of the energy subsystem. The energy conservation equation of the heat pump unit can be constructed based on the principle of energy conservation. The energy conservation equation of the heat pump unit is used to describe the interrelationship between parameters such as the chilled water operating flow rate of the heat pump unit, the chilled water supply temperature of the heat pump unit, the chilled water return temperature, the rated cooling capacity of the heat pump unit, and the operating load rate of the heat pump unit, as shown in equations (8) and (9):

[0102] (8)

[0103] (9)

[0104] in, Indicates Energy conservation load factor of the heat pump unit of each energy subsystem; Indicates Rated cooling capacity of the heat pump unit of each energy subsystem, in kW; Indicates the density of frozen water, unit ; Indicates the specific heat capacity of chilled water, unit ; Indicates Chilled water flow rate of heat pump unit in each energy subsystem, unit ; Indicates The chilled water outlet temperature of the heat pump unit of each energy subsystem, in °C; Indicates the chilled water return temperature of the regional cold source system, in °C; Indicates The operating load rate of the heat pump unit of each energy subsystem.

[0105] Since the cooling water outlet temperature of the heat pump unit of the energy subsystem in the above formula (7) is a known term, the heat pump unit model can be converted into a model associated with cooling power and operating load rate according to formula (9), as shown in formula (10):

[0106] (10)

[0107] The meanings of the symbols in formula (10) are the same as those in formulas (9) and (7).

[0108] According to an embodiment of the present invention, for the above Figure 1 In operation S120, based on the numerically stable dual solution method, the regional cold source system heat pump group control optimization model is solved and optimized to obtain the optimized operating load rate of the heat pump units of the energy subsystems. The operation may include: constructing a Lagrangian function to convert the regional cold source system heat pump group control optimization model into a Lagrangian form. Constructing a dual function of the regional cold source system heat pump group control optimization model, and solving the dual problem by maximizing the dual function. The optimal solution of the regional cold source system heat pump group control optimization model is obtained through the dual solution.

[0109] Constructing the Lagrangian function, converting the regional cooling system heat pump group control optimization model into the Lagrangian form can include the following operations: first, introduce the Lagrangian multiplier, for the equality constraint , introduce the Lagrange multiplier in the equation ; For inequality constraints , introduce the inequality term Lagrange multiplier The Lagrangian function can be written as follows:

[0110] (11) Among them, express The dimension is the identity matrix, and T represents the transpose.

[0111] Constructing the dual function of the regional cooling system heat pump group control optimization model, solving the dual problem by maximizing the dual function can include operations: using the Carlo-Kuhn-Tucker condition (KKT condition) of the Lagrangian function, we can get , The dual function constructed by the dual function can be written in the form of formula (12):

[0112] (12)

[0113] The dual problem, namely maximizing the dual function, can be expressed as As shown, the optimal solution to maximize the dual function is the optimal value of the Lagrange multiplier of the inequality term , Lagrange multiplier optimization value of equation .

[0114] The optimal solution of the heat pump group control optimization model of the regional cooling source system is obtained through the dual solution , as shown in the following formula (13):

[0115] (13)

[0116] To ensure numerical stability, you can use appropriate numerical methods and avoid numerical errors. For example, you can use high-precision floating-point numbers for calculations and set appropriate tolerances to avoid rounding errors or calculation instability; during the calculation process, ensure that the numerical size is moderate to avoid overflow or underflow, especially when performing matrix multiplication or inversion.

[0117] According to the embodiments of the present invention, the regional cold source system heat pump group control optimization method proposed in the present invention can improve the energy utilization efficiency and operation stability of the regional cold source system by accurately calculating and optimizing the operation load rate and chilled water outlet temperature of the heat pump units of each energy subsystem. For example, by constructing the energy conservation equation of the heat pump unit and constructing the first constraint condition, the operation state of the heat pump unit of each energy subsystem can be accurately controlled, thereby improving the overall refrigeration efficiency of the regional cold source system, ensuring that the chilled water outlet temperature fluctuates within a safe range, and optimizing the operation load rate of the heat pump unit of each energy subsystem, making the system operation more energy-efficient and reliable. It can realize accurate load regulation and energy efficiency optimization in a complex regional cold source system, and has broad application prospects and practical significance.

[0118] According to an embodiment of the present invention, the operation mode of the regional cold source system is optimized by using the regional cold source system heat pump group control optimization method proposed in the present invention, which can reduce the system's power consumption and maintenance costs, reduce operating expenses, and provide users with a more economical and efficient regional cold source system solution.

[0119] According to the embodiments of the present invention, the regional cold source system heat pump group control optimization method proposed by the present invention has strong adaptability and broad application prospects. For example, the method is not only applicable to regional cold source systems of different sizes and types, but also can flexibly adjust the control strategy according to actual operation requirements. It has strong adaptability and can be widely used in urban centralized air conditioning, industrial cooling and other scenarios that require regional cold source systems. The present invention not only improves the operating efficiency of the regional cold source system through an innovative optimization control method, but also ensures the stability and safety of the regional cold source system, providing theoretical support and technical guarantee for the intelligent and energy-saving development of the regional cold source system.

[0120] Figure 4A block diagram of a heat pump group control optimization device for a regional cold source system according to an embodiment of the present invention is shown.

[0121] The regional cooling source system includes multiple energy subsystems, and the energy subsystem includes a heat pump unit.

[0122] like Figure 4 As shown, the regional cold source system heat pump group control optimization device includes a construction module 410, an optimization module 420 and a determination module 430.

[0123] The construction module 410 is used to construct a heat pump group control optimization model for the regional cold source system based on the operating load rate of the heat pump units of the energy subsystems.

[0124] The optimization module 420 is used to solve and optimize the heat pump group control optimization model of the regional cold source system based on a numerically stable dual solution method to obtain the optimized operating load rate of the heat pump units of each energy subsystem.

[0125] The determination module 430 is used to determine the optimized chilled water outlet temperature of the heat pump units of the energy subsystems based on the optimized operating load rate of the heat pump units of the energy subsystems.

[0126] According to an embodiment of the present invention, any multiple modules in the construction module 410, the optimization module 420 and the determination module 430 can be combined into one module for implementation, or any one of the modules can be split into multiple modules. Alternatively, at least part of the functions of one or more of these modules can be combined with at least part of the functions of other modules and implemented in one module. According to an embodiment of the present invention, at least one of the construction module 410, the optimization module 420 and the determination module 430 can be at least partially implemented as a hardware circuit, such as a field programmable gate array (FPGA), a programmable logic array (PLA), a system on a chip, a system on a substrate, a system on a package, an application-specific integrated circuit (ASIC), or can be implemented by hardware or firmware such as any other reasonable way of integrating or packaging the circuit, or implemented in any one of the three implementation methods of software, hardware and firmware or in any appropriate combination of any of them. Alternatively, at least one of the construction module 410, the optimization module 420 and the determination module 430 can be at least partially implemented as a computer program module, and when the computer program module is run, the corresponding function can be executed.

[0127] It should be noted that the regional cold source system heat pump group control optimization device part in the embodiment of the present invention corresponds to the regional cold source system heat pump group control optimization method part in the embodiment of the present invention. The description of the regional cold source system heat pump group control optimization device part specifically refers to the regional cold source system heat pump group control optimization method part, which will not be repeated here.

[0128] It will be appreciated by those skilled in the art that the features described in the various embodiments of the present invention may be combined and / or combined in various ways, even if such combinations or combinations are not explicitly described in the present invention. In particular, without departing from the spirit and teachings of the present invention, the features described in the various embodiments of the present invention may be combined and / or combined in various ways. All of these combinations and / or combinations fall within the scope of the present invention.

[0129] The embodiments of the present invention are described above. However, these embodiments are only for the purpose of illustration, and are not intended to limit the scope of the present invention. Although each embodiment is described above, it does not mean that the measures in each embodiment cannot be used in combination advantageously. Without departing from the scope of the present invention, those skilled in the art may make various substitutions and modifications, which should all fall within the scope of the present invention.

Claims

1. A method for optimizing heat pump group control in a regional cold source system, characterized in that: The regional cold source system includes a plurality of energy subsystems, wherein the energy subsystem includes a heat pump unit; The method comprises: Based on the linear relationship between the chilled water demand parameter of the regional cold source system and the operating load rate of the heat pump unit of each of the energy subsystems, an equation constraint is performed to obtain a first constraint condition, wherein the chilled water demand parameter of the regional cold source system includes: chilled water return temperature and chilled water supply temperature; Based on the safe operation condition of the chilled water outlet temperature, constraining the upper limit and lower limit of the operation load rate of the heat pump unit of each of the energy subsystems to obtain a second constraint condition; Based on the relationship between the operating load rate and the cooling power of the heat pump units of the energy subsystems, a quadratic function is used to obtain an objective function with the operating load rate as an independent variable, and minimization of the objective function is used as an optimization goal to obtain an optimized objective function; Determine the optimization objective function, the first constraint condition and the second constraint condition as a regional cold source system heat pump group control optimization model; Based on the numerically stable dual solution method, the heat pump group control optimization model of the regional cold source system is solved and optimized to obtain the optimized operating load rate of the heat pump unit of each energy subsystem; Based on the optimized operating load rate of the heat pump unit of each of the energy subsystems, the optimized chilled water outlet temperature of the heat pump unit of each of the energy subsystems is determined.

2. The method according to claim 1, characterized in that: The linear relationship between the chilled water demand parameter of the regional cold source system and the operating load rate of the heat pump unit of each of the energy subsystems is subjected to an equality constraint to obtain a first constraint condition, including: Obtaining a temperature difference according to a difference between the chilled water return temperature and the chilled water supply temperature; The first constraint condition is obtained by performing an equality constraint based on the indirect correlation between the temperature difference and the operating load rate of the heat pump unit of each energy subsystem.

3. The method according to claim 2, characterized in that The first constraint condition includes the following formula (1): （1） in, represents the number of the energy subsystems of the regional cooling system, Indicates The mixed water load factor of each energy subsystem is Indicates The operating load rate of the heat pump unit of each energy subsystem is represents the chilled water return temperature, Indicates the chilled water supply temperature; The said Mixed water load factor for each energy subsystem Including formula (2): （2） in, Indicates The number of heat pump units in operation in each energy subsystem, Indicates Chilled water flow rate of heat pump unit in each energy subsystem, unit , It represents the total chilled water flow rate of the regional cold source system, in units of , Indicates The energy conservation load factor of the heat pump unit of the energy subsystem is The energy conservation load factor of the heat pump unit of the energy subsystem is based on the The rated cooling capacity of the heat pump unit of the energy subsystem and the The chilled water operating flow rate of the heat pump unit of each energy subsystem is determined.

4. The method according to claim 1, characterized in that: The second constraint condition includes an upper limit constraint condition and a lower limit constraint condition; The upper limit constraint condition includes the following formula (3): （3） The lower limit constraint condition includes the following formula (4): （4） in, Indicates The lower limit of the operating load rate of the heat pump unit of each energy subsystem is Indicates The upper limit of the operating load rate of the heat pump unit of each energy subsystem is Indicates The maximum chilled water outlet temperature of the heat pump unit of each energy subsystem, in °C, Indicates The minimum chilled water outlet temperature of the heat pump unit of each energy subsystem, in °C, Indicates The energy conservation load factor of the heat pump unit of each energy subsystem is: Indicates The minimum operating load rate of the heat pump unit of each energy subsystem, Indicates The maximum operating load rate of the heat pump unit of the energy subsystem is The energy conservation load factor of the heat pump unit of the energy subsystem is based on the The rated cooling capacity of the heat pump unit of the energy subsystem and the The chilled water operating flow rate of the heat pump unit of each energy subsystem is determined.

5. The method according to claim 1, characterized in that The relationship between the operating load rate and the cooling power of the heat pump units of the energy subsystems is obtained by using a quadratic function, and the objective function with the operating load rate as an independent variable is obtained. The optimization objective function is obtained by minimizing the objective function as an optimization objective, including: For the heat pump unit of each energy subsystem: Constructing a heat pump unit model of the energy subsystem based on the chilled water outlet temperature, the cooling water outlet temperature and the operating load rate of the heat pump unit; Based on known items in the heat pump unit model and the energy conservation principle, converting the heat pump unit model into a model associated with the refrigeration power and the operating load rate; Determining the quadratic Hessian matrix of the quadratic function based on the relationship between the parameters of the model associated with the refrigeration power and the operating load rate, the energy conservation load rate coefficient of the heat pump unit, and the rated refrigeration power of the heat pump unit, wherein the energy conservation load rate coefficient of the heat pump unit is determined based on the rated refrigeration capacity of the heat pump unit and the chilled water operating flow rate of the heat pump unit; Determine the linear term vector of the quadratic function based on the relationship between the parameters of the model associated with the refrigeration power and the operating load rate, the energy conservation load rate coefficient of the heat pump unit, the rated refrigeration power of the heat pump unit, the cooling water outlet temperature and the chilled water return temperature; Based on the quadratic Hessian matrix and the linear vector, construct an objective function with the operating load rate as an independent variable; Taking minimizing the objective function as the optimization goal, the optimization objective function regarding the operating load rate of the heat pump unit is obtained.

6. The method according to claim 5, characterized in that The regional cold source system heat pump group control optimization model includes the following formula (5): （5） in, Indicates The objective function of the heat pump group control optimization model of the regional cold source system is the independent variable, Represents the operating load rate vector of the heat pump units of the energy subsystems, with dimension , represents the number of the energy subsystems of the regional cooling system, , represents the quadratic Hessian matrix, dimension , , represents the second order Hessian matrix of the quadratic term diagonal elements, , Indicates The rated cooling power of the heat pump unit of each energy subsystem is Indicates The energy conservation load factor of the heat pump unit of each energy subsystem is: represents the first-order vector, dimension , , represents the first order vector elements, , represents the chilled water return temperature, Indicates the The cooling water outlet temperature of the heat pump unit of each energy subsystem; , …, In turn, the The first to ninth model coefficients of the model associated with the cooling power and the operating load rate of the energy subsystem, The left-hand matrix of the equality constraint is , , Indicates The mixed water load factor of each energy subsystem is Represents the right-hand side vector of the equality constraint, dimension , , represents the chilled water supply temperature, Represents the lower limit vector of the operating load rate of the heat pump unit of each energy subsystem, with dimension , , Indicates The lower limit of the operating load rate of the heat pump unit of each energy subsystem is Represents the upper limit vector of the operating load rate of the heat pump unit of each energy subsystem, with dimension , , Indicates The upper limit of the operating load rate of the heat pump unit of each energy subsystem.

7. The method according to any one of claims 1 to 6, characterized in that: The step of determining the optimized chilled water outlet temperature of the heat pump unit of each energy subsystem based on the optimized operation load rate of the heat pump unit of each energy subsystem comprises: For the heat pump unit of each energy subsystem: Obtaining a loss temperature difference according to the product of the optimized operation load rate of the heat pump unit and the energy conservation load rate coefficient of the heat pump unit, wherein the energy conservation load rate coefficient of the heat pump unit is determined based on the rated cooling capacity of the heat pump unit and the chilled water operation flow rate of the heat pump unit; The optimized chilled water outlet temperature is obtained according to the difference between the chilled water return temperature and the loss temperature difference.

8. The method according to claim 7, characterized in that The optimized chilled water outlet temperature is as shown in formula (6): （6） in, Indicates The optimal chilled water outlet temperature of the heat pump unit of each energy subsystem, represents the chilled water return temperature, Indicates The energy conservation load factor of the heat pump unit of each energy subsystem is: Indicates The optimal operating load rate of the heat pump unit of the energy subsystem is The energy conservation load factor of the heat pump unit of the energy subsystem is based on the The rated cooling capacity of the heat pump unit of the energy subsystem and the The chilled water operating flow rate of the heat pump unit of each energy subsystem is determined.

9. A heat pump group control optimization device for a regional cold source system, characterized in that: The regional cold source system includes a plurality of energy subsystems, wherein the energy subsystem includes a heat pump unit; The device comprises: A construction module, for constructing a heat pump group control optimization model for a regional cold source system based on the operation load rate of the heat pump units of the energy subsystems; An optimization module, for solving and optimizing the heat pump group control optimization model of the regional cold source system based on a numerically stable dual solution method, and obtaining an optimized operating load rate of the heat pump unit of each energy subsystem; A determination module, configured to determine an optimized chilled water outlet temperature of each of the heat pump units of the energy subsystems based on an optimized operating load rate of each of the heat pump units of the energy subsystems; The building blocks are specifically used to perform the following operations: Based on the linear relationship between the chilled water demand parameter of the regional cold source system and the operating load rate of the heat pump unit of each of the energy subsystems, an equation constraint is performed to obtain a first constraint condition, wherein the chilled water demand parameter of the regional cold source system includes: chilled water return temperature and chilled water supply temperature; Based on the safe operation condition of the chilled water outlet temperature, constraining the upper limit and lower limit of the operation load rate of the heat pump unit of each of the energy subsystems to obtain a second constraint condition; Based on the relationship between the operating load rate and the cooling power of the heat pump units of the energy subsystems, a quadratic function is used to minimize the objective function with the operating load rate as an independent variable to construct an optimization objective function; The optimization objective function, the first constraint condition and the second constraint condition are determined as the regional cold source system heat pump group control optimization model.

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