A method for evaluating energy efficiency of composite energy system

Abstract

The present application discloses a method for evaluating the energy efficiency of a composite energy system, including: respectively collecting the operating parameters of the composite energy system, the composite energy system includes a ground source heat pump system and an auxiliary coupling system, the auxiliary coupling system includes a chiller system, an air source heat pump system and a gas boiler system; respectively calculating the energy efficiency indicators of the ground source heat pump system, the chiller system, the air source heat pump system and the gas boiler system according to the collected operating parameters; calculating the operating energy efficiency and operating cost efficiency of the composite energy system; calculating the comprehensive system operating energy efficiency of the composite energy system according to the calculated energy efficiency indicators; calculating the energy saving rate according to the comprehensive system operating energy efficiency; and evaluating the energy efficiency of the composite energy system according to the calculated operating energy efficiency, operating cost efficiency, comprehensive system operating energy efficiency and energy saving rate. In view of the fact that the calculation of the energy saving rate in the composite energy system existing in the prior art is often complicated, the present application simplifies the calculation of the energy saving rate.

Description

Technical Field

[0001] The present application relates to the technical field of ground source heat pump evaluation, and in particular to a method for evaluating the energy efficiency of a composite energy system. Background Art

[0002] In today's society, the improvement of energy efficiency and environmental sustainability have become important issues worldwide. With the continuous growth of energy demand and concerns about environmental impact, the design and operation of various composite energy systems have become crucial. The premise for calculating the energy saving rate is to obtain the energy consumption of the system before and after the adoption of energy-saving technology, but it is often difficult to obtain the energy consumption data of the system through measurement or simulation.

[0003] The current energy saving rate evaluation methods often only consider local factors and fail to fully consider the comprehensive performance of multi-composite energy systems. In addition, there is a lack of a unified and comprehensive evaluation standard for different types of composite energy systems, which leads to the one-sidedness and inaccuracy of the evaluation results.

[0004] In the related technology, for example, Chinese patent document CN116432526A provides a refined evaluation method for the long-term operation performance of a ground source heat pump system. It uses a design parameter data group simulation calculation to establish a ground pipe heat exchanger-heat pump-building coupled heat transfer model database; establishes a mapping between design parameters and operation results to form a neural network model for fitting the long-term operation performance of the ground source heat pump system; inputs the design parameters, uses the neural network model to fit and predict the energy efficiency ratio, energy conservation and emission reduction, and ground temperature in the buried pipe area, and finely evaluates the applicability, economy, and environmental protection of the long-term operation of the system. However, the performance of the neural network model is highly dependent on the quality and quantity of the training data. If the training data is insufficient or does not represent the overall performance of the system, the model may not accurately fit the actual operation. Summary of the invention

[0005] 1. Technical problems to be solved

[0006] In view of the fact that the calculation of energy saving rate in the composite energy system existing in the prior art is often complicated, the present application provides a composite energy system energy efficiency evaluation method, which calculates the energy saving rate by comparing with the energy efficiency limit, thereby simplifying the calculation of the energy saving rate.

[0007] 2. Technical solution

[0008] The purpose of the present invention is achieved through the following technical solutions.

[0009] The embodiment of the present specification provides a method for evaluating the energy efficiency of a composite energy system, comprising: respectively collecting operating parameters of the composite energy system, the composite energy system comprising a ground source heat pump system and an auxiliary coupling system, the auxiliary coupling system comprising a chiller system, an air source heat pump system and a gas boiler system; respectively calculating the energy efficiency indicators of the ground source heat pump system, the chiller system, the air source heat pump system and the gas boiler system according to the collected operating parameters; calculating the operating energy efficiency and operating cost efficiency of the composite energy system according to the collected operating parameters; calculating the comprehensive system operating energy efficiency of the composite energy system according to the calculated energy efficiency indicators of the ground source heat pump system, the chiller system, the air source heat pump system and the gas boiler system; calculating the energy saving rate of the composite energy system according to the calculated comprehensive system operating energy efficiency of the composite energy system; and performing energy efficiency evaluation on the composite energy system according to the calculated operating energy efficiency, operating cost efficiency, comprehensive system operating energy efficiency and energy saving rate.

[0010] Among them, the operating parameters include: Ground source heat pump system: cumulative cooling capacity of heat pump unit in cooling season Q gc , Cumulative power consumption of heat pump unit in cooling season W ghp1 , the cumulative heating supply of the heat pump unit in the heating season Q gh , Cumulative power consumption of heat pump units in heating season W ghp2 Cumulative power consumption of underground water pump in heating season W gp2 ; Cumulative power consumption of user-side water pump in cooling season W up1 , Cumulative power consumption of underground water pump in cooling season W gp1 , Cumulative power consumption of water pumps on the user side during the heating season W up2 , Cumulative power consumption of user-side water pumps in cooling season W aup1 The cumulative power consumption of the water pump on the user side during the heating season W aup2 ; Chiller system: Accumulated cooling capacity of chiller in cooling season Q c0 , Cumulative power consumption of chillers in cooling season W ch , Cumulative power consumption of chilled water pump in cooling season W chp , Cooling water pump cumulative power consumption in cooling season W cp And the cumulative power consumption of cooling tower in cooling season W ct ; Air source heat pump system: cumulative cooling capacity of heat pump unit in cooling season Q ac , Cumulative power consumption of heat pump unit in cooling season W ahp1 , the cumulative heating supply of the heat pump unit in the heating season Q ah , Cumulative power consumption of heat pump units in heating season W ahp2 .

[0011] Optimal gas boiler system: Municipal thermal system: Plate heat exchanger cumulative heat transfer Q h1 , Plate heat exchanger secondary side water pump cumulative power consumption W sp1; Gas boiler system: plate heat exchanger cumulative heat transfer capacity Q h2 , gas boiler cumulative gas consumption V g , Plate heat exchanger primary side water pump cumulative power consumption W pp And the cumulative power consumption of the secondary side water pump W sp2 .

[0012] Among them, the hybrid energy system is a broader concept, including all equipment and facilities for energy conversion and utilization. In this context, the hybrid energy system covers the ground source heat pump system and the auxiliary coupling system. The operating parameters of the hybrid energy system may include overall performance indicators such as overall energy consumption, total heat output, energy input and output, as well as the operating status of each subsystem. The ground source heat pump system is a system that uses underground thermal energy for space heating or space cooling. It uses the relatively stable underground temperature to achieve energy conversion through geothermal heat exchangers and heat pumps. The operating parameters of the ground source heat pump system may include the inlet temperature and outlet temperature of the geothermal heat exchanger, the efficiency of the heat pump, the operating status of the compressor, etc. The auxiliary coupling system is a group of systems that work in conjunction with the ground source heat pump system, usually including a chiller system and an air source heat pump system. The role of these systems is to provide additional cooling or heating support when needed. The operating parameters of the auxiliary coupling system will involve specific parameters of the chiller system and the air source heat pump system. The chiller system may include parameters such as cooling water temperature and cooling water flow; the air source heat pump system may include parameters such as air temperature and heat pump efficiency.

[0013] Among them, the ground source heat pump system mainly uses underground thermal energy for energy conversion, while the auxiliary coupling system provides additional support and can include other forms of heat pump systems (such as air source heat pumps) and chiller systems. In terms of operating parameters, the ground source heat pump system focuses on the performance parameters of the geothermal heat exchanger and heat pump, while the auxiliary coupling system focuses on the parameters of the specific systems related to it. The ground source heat pump system and the auxiliary coupling system work together in the composite energy system to provide support for space heating and cooling. As a supplement, the auxiliary coupling system can provide additional energy support when needed, thereby improving the flexibility and performance of the overall system.

[0014] Among them, the parameters of the cooling season and the heating season reflect the performance of the system in different seasons. The parameters of the cooling season focus on the cooling performance, while the parameters of the heating season focus on the heating performance. The cumulative cooling capacity and cumulative heating capacity are the total services provided by the system in the corresponding season, while the cumulative power consumption is expressed as the total power consumed by the system to provide these services. The power consumption of the user-side water pump and the underground-side water pump represents the power consumption of the water pump in the system, providing corresponding water circulation services for the user side and the underground side respectively.

[0015] Among them, the conventional chiller system is mainly composed of a chiller, a chilled water pump, a cooling water pump and a cooling tower. The chiller water system includes a chilled water system and a cooling water system. The chilled water is cooled to about 7°C by the evaporator of the chiller, and is transported to the end user by the chilled water pump. It is heated to about 12°C at the end and returns to the chiller evaporator, and the cycle repeats; the cooling water is heated to about 37°C by the condenser of the chiller, and is transported to the cooling tower by the cooling water pump. It is cooled to about 32°C by the fan and spray in the cooling tower and then returns to the chiller condenser, and the cycle repeats. The chiller, chilled water pump, cooling water pump and cooling tower all need to consume electricity to do work, thereby transferring heat from indoors to outdoors to achieve the purpose of cooling.

[0016] Among them, the actual measured EER, COP, and CER are compared with the industry standard or the average value of similar systems to analyze whether the system performance reaches or exceeds the industry level. Combined with CER to evaluate the economic benefits of the system, energy prices, operating costs, and maintenance costs are considered to determine the overall cost-effectiveness of the system. The energy efficiency performance of the system can be rated according to the above indicators, such as leading level, level 1, level 2, and level 3. Based on the current energy efficiency evaluation results, improvement goals can be set, and methods to improve EER, COP, and energy saving rate can be proposed to reduce CER to improve overall energy efficiency. Based on the evaluation results, specific optimization plans are formulated, such as improving equipment configuration and optimizing operation strategies.

[0017] Furthermore, the operating energy efficiency includes the comprehensive operating energy efficiency EER of the chiller system. c , measures the performance of the chiller in the cooling season; the EER of the ground source heat pump system g , reflecting the performance of the ground source heat pump system in the cooling season; the comprehensive heating operation energy efficiency COP of the ground source heat pump system g , which represents the performance of the ground source heat pump system in the heating season; the comprehensive cooling energy efficiency EER of the air source heat pump system a , reflects the efficiency of the air source heat pump system in the cooling season; the comprehensive heating operation energy efficiency COP of the air source heat pump system a , which indicates the performance of the air source heat pump system in the heating season; the instantaneous cooling energy efficiency ratio EER of the chiller or heat pump unit i , which indicates the cooling performance of the system under instantaneous conditions; the instantaneous heating coefficient COP of the ground source heat pump system i , reflecting the heating performance of the system under instantaneous conditions; the instantaneous cooling capacity EER of the air source heat pump system ai , which indicates the cooling performance of the system under instantaneous conditions; the instantaneous heating coefficient COP of the air source heat pump system ai , reflecting the heating performance of the system under instantaneous conditions.

[0018] Furthermore, the comprehensive operating energy efficiency EER of the chiller system c Calculated by the following formula:

[0019]

[0020] Among them, the chiller system: the cumulative cooling capacity of the chiller in the cooling season is Q c0 , which is related to the cooling service provided by the system in summer, and reflects the performance of the system in the cooling season; the cumulative power consumption of the chiller in the cooling season is W ch , represents the power consumed by the system when providing refrigeration services during the cooling season; the cumulative power consumption of the chilled water pump during the cooling season W chp , represents the power consumed by the chilled water pump when providing chilled water circulation service for the system during the cooling season; the cumulative power consumption of the cooling water pump during the cooling season W cp , represents the power consumed by the cooling water pump when providing cooling water circulation service for the system during the cooling season; the cumulative power consumption of the cooling tower during the cooling season W ct , which represents the electricity consumed by the cooling tower when providing heat dissipation services for the system during the cooling season.

[0021] Comprehensive cooling operation energy efficiency EER of ground source heat pump system g Calculated by the following formula:

[0022]

[0023] Among them, the cumulative cooling capacity of the heat pump unit in the cooling season is Q gc , which is related to the cooling service provided by the system in summer and reflects the performance of the system in the cooling season; the cumulative power consumption of the heat pump unit in the cooling season is W ghp1 , represents the power consumed by the system when providing cooling services in the cooling season; the cumulative power consumption of the user-side water pump in the cooling season is W up1 , represents the power consumed by the user-side water pump when providing cold water or cooling services to users during the cooling season; the cumulative power consumption of the underground side water pump during the cooling season W gp1 , represents the power consumed by the underground water pump when providing circulating water service for geothermal wells or geothermal heat exchangers in the cooling season;

[0024] Comprehensive heating operation efficiency COP of ground source heat pump system g Calculated by the following formula:

[0025]

[0026] Among them, the cumulative heat supply of the heat pump unit in the heating season is Q gh , which is related to the system's provision of heating services in winter and reflects the system's performance in the heating season; the cumulative power consumption of the heat pump unit in the heating season is W ghp2, represents the power consumed by the system when providing heating services during the heating season; the cumulative power consumption of the user-side water pump during the heating season W up2 , represents the power consumed by the user-side water pump when providing hot water or heating services to users during the heating season; the cumulative power consumption of the underground water pump during the heating season W gp2 , which represents the electricity consumed by the underground water pump when providing circulating water services for geothermal wells or geothermal heat exchangers during the heating season.

[0027] Comprehensive refrigeration operation energy efficiency (EER) of air source heat pump system a Calculated by the following formula:

[0028]

[0029] Among them, the cumulative cooling capacity of the heat pump unit in the cooling season is Q ac , which is related to the cooling service provided by the system in summer and reflects the performance of the system in the cooling season; the cumulative power consumption of the heat pump unit in the cooling season is W ahp1 , represents the power consumed by the system when providing cooling services in the cooling season; the cumulative power consumption of the user-side water pump in the cooling season is W aup1 , represents the electricity consumed by the user-side water pump when providing cold water or cooling services to users during the cooling season;

[0030] Comprehensive heating operation energy efficiency COP of air source heat pump system a Calculated by the following formula:

[0031]

[0032] Among them, the cumulative heat supply of the heat pump unit in the heating season is Q ah , which is related to the system's provision of heating services in winter and reflects the system's performance in the heating season; the cumulative power consumption of the heat pump unit in the heating season is W ahp2 , represents the power consumed by the system when providing heating services during the heating season; the cumulative power consumption of the user-side water pump during the heating season W aup2 , which represents the electricity consumed by the user-side water pump when providing hot water or heating services to users during the heating season.

[0033] Furthermore, the instantaneous cooling energy efficiency ratio (EER) of the chiller or heat pump unit is i Calculated by the following formula:

[0034] EER i =(A1r 3 +B1r 2 +C1r+D1)×[1-0.03×(t cs -t cc )]×[1+0.02×(t es -t ec )]

[0035] Among them, A1, B1, C1 and D1 represent the coefficients of the EER fitting formula of the partial load of the chiller or heat pump unit under refrigeration conditions, which reflect the performance of the unit under different conditions; t cs Indicates the actual outlet water temperature of the condenser of the chiller or heat pump unit under actual working conditions, indicating the actual outlet water temperature of the condenser under the cooling condition of the unit; t cc Indicates the outlet water temperature of the condenser of the chiller or heat pump unit under the refrigeration design condition, representing the outlet water temperature of the condenser under the refrigeration design condition of the unit; t es Indicates the actual outlet water temperature of the evaporator of the chiller or heat pump unit under actual working conditions, indicating the actual outlet water temperature of the evaporator under the evaporation condition of the unit; t ec It indicates the outlet water temperature of the evaporator of the chiller or heat pump unit under the refrigeration design condition, which represents the outlet water temperature of the evaporator under the refrigeration design condition of the unit;

[0036] Instantaneous heating efficiency COP of ground source heat pump system i Calculated by the following formula:

[0037] COP i =(E1r 3 +F1r 2 +G1r+H1)×[1-0.03×(t cs -t ch )]×[1+0.02×(t es -t eh )]

[0038] Among them, E1, F1, G1 and H1 represent the coefficients of the partial load COP fitting formula of the heat pump unit under heating conditions, which reflect the performance of the heat pump unit under different conditions; r represents the load ratio, which reflects the size of the system load under actual conditions relative to the design conditions; t cs Indicates the actual outlet water temperature of the condenser of the chiller or heat pump unit under actual working conditions, and indicates the actual outlet water temperature of the condenser of the unit under heating conditions; t ch Indicates the outlet water temperature of the heat pump unit condenser under heating design conditions, representing the outlet water temperature of the condenser under heating design conditions; t es Indicates the actual outlet water temperature of the evaporator of the chiller or heat pump unit under actual working conditions, indicating the actual outlet water temperature of the evaporator under the evaporation condition of the unit; t eh It indicates the outlet water temperature of the evaporator of the heat pump unit under the heating design condition, which represents the outlet water temperature of the evaporator under the heating design condition of the unit;

[0039]

[0040] Among them, n represents the number of chillers or heat pumps that are turned on, reflecting the number of chillers or heat pumps running simultaneously in the system. The coordinated operation of multiple units can affect the overall performance of the system; Q0 represents the cooling capacity or heating capacity of the chiller or heat pump under the design conditions, representing the total amount of cooling or heating services that the system can provide under the design conditions. This is a value determined based on system design and specifications; Q i Indicates the instantaneous cooling capacity or heating capacity of a chiller or heat pump unit, indicating the total amount of cooling or heating services provided by the system under instantaneous conditions. Different from the cooling or heating capacity under design conditions, this is a value under actual operating conditions;

[0041] Furthermore, the instantaneous cooling energy efficiency ratio EER of the air source heat pump system ai Calculated by the following formula:

[0042] EER ai =(A2t w 3 +B2t w 2 +C2t w +D2)×[1+0.02×(t es -t ec )]

[0043] Among them, A2, B2, C2 and D2 represent the fitting formula coefficients of the unit's refrigeration condition EER changing with outdoor temperature. The values ​​of these coefficients are determined by the fitting formula to reflect the unit's refrigeration performance at different outdoor temperatures; t es Indicates the actual outlet water temperature of the evaporator of the chiller or heat pump unit under actual working conditions, indicating the actual outlet water temperature of the evaporator under the evaporation condition of the unit; t ec It indicates the outlet water temperature of the evaporator of the chiller or heat pump unit under the refrigeration design condition, which represents the outlet water temperature of the evaporator under the refrigeration design condition of the unit; t w Indicates the outdoor air dry bulb temperature, which indicates the temperature of the outdoor air, which is one of the external environmental conditions that affects the performance of the refrigeration system;

[0044] Instantaneous heating efficiency COP of air source heat pump system ai Calculated by the following formula:

[0045] COP ai =(E2t w 3 +F2t w 2 +G2t w +H2)×[1-0.03×(t cs -t ch )]

[0046] Among them, t wIt represents the outdoor air dry bulb temperature, which is one of the external environmental conditions that affect the performance of the heating system. E2, F2, G2 and H2 represent the fitting formula coefficients that change with the outdoor temperature; t cs Indicates the actual outlet water temperature of the condenser of the chiller or heat pump unit under actual working conditions, and indicates the actual outlet water temperature of the condenser of the unit under heating conditions. ch Indicates the outlet water temperature of the heat pump unit condenser under heating design conditions, representing the outlet water temperature of the condenser under heating design conditions;

[0047] Furthermore, the comprehensive cooling energy efficiency ratio EER is calculated by the following formula:

[0048]

[0049] Among them, EER bg It represents the comprehensive cooling energy efficiency ratio of the office building cooling system, which reflects the overall performance of the cooling system in the office building and takes into account the energy efficiency performance of the system under different working conditions; EER jd It represents the comprehensive cooling energy efficiency ratio of the hotel building cooling system, which characterizes the overall performance of the cooling system in the hotel building, including the cooling efficiency under various usage conditions; EER sc It represents the comprehensive refrigeration energy efficiency ratio of the refrigeration system of the shopping mall building, which describes the overall performance of the refrigeration system in the shopping mall building and takes into account the refrigeration requirements in the shopping mall environment; EER yy It represents the comprehensive refrigeration energy efficiency ratio of the hospital building refrigeration system, reflecting the overall performance of the refrigeration system in the hospital building, taking into account the refrigeration effect under the special needs of the hospital; EER xx It represents the comprehensive cooling energy efficiency ratio of the school building cooling system, which represents the overall performance of the cooling system in the school building, including the cooling performance in the school environment; bg represents the proportion of office building area; p jd represents the proportion of hotel building area; p sc represents the proportion of shopping mall building area; p yy represents the proportion of hospital building area; p xx It represents the proportion of school building area, reflects the relative importance of various types of buildings in the whole system, and is used to calculate the comprehensive cooling energy efficiency ratio according to the different weights of building types.

[0050] The comprehensive heating efficiency ratio COP is calculated by the following formula:

[0051]

[0052] Among them, COP bg It represents the comprehensive heating energy efficiency ratio of the heat pump system in the office building, describes the overall heating performance of the heat pump system in the office building, and takes into account the energy efficiency performance of the system under different working conditions; COPjd It indicates the comprehensive heating energy efficiency ratio of the heat pump system in the hotel building, reflecting the overall heating performance of the heat pump system in the hotel building, including the heating efficiency under various usage conditions; COP sc It represents the comprehensive heating energy efficiency ratio of the heat pump system in the shopping mall building, which represents the overall heating performance of the heat pump system in the shopping mall building, taking into account the heating demand in the shopping mall environment; COP yy It represents the comprehensive heating energy efficiency ratio of the heat pump system in the hospital building, reflecting the overall heating performance of the heat pump system in the hospital building, taking into account the heating effect under the special needs of the hospital; COP xx It represents the comprehensive heating energy efficiency ratio of the heat pump system in the school building, and describes the overall heating performance of the heat pump system in the school building, including the heating performance in the school environment; bg represents the proportion of office building area; p jd represents the proportion of hotel building area; p sc represents the proportion of shopping mall building area; p yy represents the proportion of hospital building area; p xx It represents the proportion of school building area, reflects the relative importance of various types of buildings in the whole system, and is used to calculate the comprehensive cooling energy efficiency ratio according to the different weights of building types.

[0053] Furthermore, energy efficiency indicators include: Energy efficiency limit EER of ground source heat pump system g,n , Energy efficiency limit COP of chiller system g,n , Refrigeration Energy Efficiency Limit EER of Air Source Heat Pump System a,n and heating energy efficiency limit COP of air source heat pump system a,n , respectively calculated by the following formulas:

[0054]

[0055]

[0056]

[0057]

[0058] Among them, EER c,n It indicates the nth level refrigeration energy efficiency limit of the chiller system, which indicates the requirements of the refrigeration performance of the (nth) level in the chiller system and is the limitation of the refrigeration efficiency of the system at different levels; EER g It represents the comprehensive cooling energy efficiency of the ground source heat pump system, describes the cooling performance of the ground source heat pump system in the overall operation, and takes into account the energy efficiency performance of the system under different working conditions; EER cIndicates the comprehensive operating energy efficiency of the chiller system, reflecting the overall operating performance of the chiller system under various operating conditions, including refrigeration efficiency and other key performance parameters; COP g It represents the comprehensive heating operation energy efficiency of the ground source heat pump system, describes the heating performance of the ground source heat pump system in the overall operation, and takes into account the energy efficiency performance of the system under different working conditions; EER a Indicates the comprehensive refrigeration operation energy efficiency of the air source heat pump system, reflecting the refrigeration performance of the air source heat pump system in the overall operation, including the energy efficiency performance of the system under different working conditions; COP a It represents the comprehensive heating operation energy efficiency of the air source heat pump system, describes the heating performance of the air source heat pump system in overall operation, and takes into account the energy efficiency performance of the system under different working conditions;

[0059] Furthermore, the cooling energy efficiency limit EER s,n Calculated by the following formula:

[0060]

[0061] Among them, EER s,n It represents the nth level cooling energy efficiency limit of the composite energy system, which represents the requirements of the (nth) level cooling performance in the composite energy system, and is the limitation of the cooling efficiency of the system at different levels; EER c,n It indicates the nth level refrigeration energy efficiency limit of the chiller system, which indicates the requirement of the (nth) level refrigeration performance in the chiller system and is the limit of the refrigeration efficiency at this level; Q c1 Indicates the cumulative cooling capacity of the chiller system, indicating the total cooling capacity of the system in a certain period of time; EER g,n It indicates the nth level refrigeration energy efficiency limit of the ground source heat pump system, which indicates the requirements of the (nth) level refrigeration performance in the ground source heat pump system and is the limit of the refrigeration efficiency at this level; Q g1 Indicates the cumulative cooling capacity of the ground source heat pump system, indicating the total cooling capacity of the ground source heat pump system in a certain period of time; EER a,n It indicates the cumulative cooling capacity of the air source heat pump system, which means the total cooling capacity of the air source heat pump system in a certain period of time; Q a1 It indicates the cumulative cooling capacity of the air source heat pump system, and the total cooling capacity of the air source heat pump system in a certain period of time.

[0062] Heating energy efficiency limit COP s,n Calculated by the following formula:

[0063]

[0064] Among them, COP s,nIt indicates the nth level heating energy efficiency limit of the composite energy system, which indicates the requirements of the (nth) level heating performance in the composite energy system, and is the limitation of the heating efficiency of the system at different levels; COP g,n It indicates the nth level heating energy efficiency limit of the ground source heat pump system, which indicates the requirement of the (nth) level heating performance in the ground source heat pump system and is the limit of the heating efficiency at this level; Q g2 Indicates the cumulative heat supply of the ground source heat pump system, indicating the total heat supply of the ground source heat pump system in a certain period of time; COP a,n It represents the nth level heating energy efficiency limit of the air source heat pump system, which represents the requirement of the (nth) level heating performance in the air source heat pump system and is the limit of the heating efficiency at this level; Q a2 It indicates the cumulative heat supply of the air source heat pump system, which indicates the total heat supply of the air source heat pump system in a certain period of time;

[0065] Furthermore, the operating cost-effectiveness (CER) of the composite energy system is calculated by the following formula:

[0066]

[0067] Among them, CER bg It represents the comprehensive cost-effectiveness ratio of the cooling and heating source system in the office building, which takes into account the economic performance of the system under different working conditions; CER jd It indicates the comprehensive cost-effectiveness ratio of the cooling and heating source system in the hotel building, reflecting the overall cost-effectiveness ratio of the cooling and heating source system in the hotel building, including the economic performance under various usage conditions; CER sc It indicates the comprehensive cost-effectiveness ratio of the cooling and heating source system in the shopping mall building, which takes into account the economic needs in the shopping mall environment; CER yy It represents the comprehensive cost-effectiveness ratio of the cooling and heating source system of the hospital building, reflecting the overall cost-effectiveness ratio of the cooling and heating source system in the hospital building, taking into account the economic performance under the special needs of the hospital; CER xx It represents the comprehensive cost-effectiveness ratio of the cooling and heating source system in school buildings, and describes the overall cost-effectiveness ratio of the cooling and heating source system in school buildings, including the economic performance in the school environment; bg represents the proportion of office building area; p jd represents the proportion of hotel building area; p sc represents the proportion of shopping mall building area; p yy represents the proportion of hospital building area; p xx Indicates the proportion of school building area.

[0068] Furthermore, the energy saving rate of the composite energy system includes: the energy saving rate of the cooling condition η ec And the energy saving rate of heating condition η eh ;

[0069] Energy saving rate η in refrigeration condition ec Calculated by the following formula:

[0070]

[0071] Among them, EER s,3 It indicates the third-level energy efficiency limit value of the hybrid energy system under refrigeration conditions, which is the minimum standard for the system's refrigeration performance. s It represents the actual refrigeration energy efficiency of the hybrid energy system. The performance of the hybrid energy system in actual refrigeration operation takes into account the refrigeration efficiency of the system under different working conditions.

[0072] Energy saving rate η of heating condition eh Calculated by the following formula:

[0073]

[0074] Among them, COP s,3 It indicates the third-level energy efficiency limit value of the heating system of the composite energy system, which indicates the third-level energy efficiency requirement of the composite energy system under heating conditions and is the minimum standard for the system's heating performance; COP s It represents the actual energy efficiency of the heating of the composite energy system. The performance of the composite energy system in actual heating operation takes into account the heating efficiency of the system under different working conditions.

[0075] 3. Beneficial effects

[0076] Compared with the prior art, the advantages of the present invention are:

[0077] This application collects the operating parameters of each subsystem in the composite energy system, calculates the energy efficiency index of each subsystem according to the collected parameters, and then obtains the comprehensive operating energy efficiency of the composite system through calculation, thereby realizing the evaluation of the overall operating efficiency of the composite system;

[0078] The energy efficiency index of the composite system is obtained by calculation and compared with the corresponding preset energy efficiency limit, so as to simplify the calculation to obtain the energy saving rate of the composite system, effectively avoiding the problem of complicated energy saving rate calculation process in the prior art;

[0079] The energy saving rate of the composite system calculated in this application can directly reflect the energy saving level and energy saving potential of the composite system, and provide a basis for the evaluation of the system operation status and the formulation of energy saving strategies;

[0080] This application also takes into account the operating cost-effectiveness of the composite system, can evaluate the cost-effectiveness of system operation, and provide guidance for the economic operation of the composite system. BRIEF DESCRIPTION OF THE DRAWINGS

[0081] This specification will be further described in the form of exemplary embodiments, which will be described in detail by the accompanying drawings. These embodiments are not restrictive, and in these embodiments, the same number represents the same structure, wherein:

[0082] Figure 1 is a schematic diagram of a composite energy system according to some embodiments of this specification;

[0083] Figure 2 It is an exemplary flow chart of a composite energy system energy efficiency evaluation method according to some embodiments of this specification. DETAILED DESCRIPTION

[0084] The method and system provided by the embodiments of this specification are described in detail below with reference to the accompanying drawings.

[0085] Figure 1 is a schematic diagram of a composite energy system according to some embodiments of this specification. According to this technical solution, Figure 1 A composite energy system using a ground source heat pump coupled with an auxiliary cold and heat source is demonstrated. In this application, due to the site limitations of the buried pipe system, a single ground source heat pump system is difficult to meet all the cold and heat needs. In order to achieve soil thermal balance, the system is additionally equipped with a chiller and an air source heat pump as auxiliary cold sources, and a gas boiler as an auxiliary heat source. In actual operation, the ground source heat pump system is first used to provide basic cooling and heating loads. Then, according to the actual size of the cold and heat loads, while considering factors such as operating costs, choose to start a chiller, air source heat pump or gas boiler as a supplement to the ground source heat pump to jointly meet the building's cold and heat needs. In this way, the ground source heat pump system is coupled with other auxiliary cold and heat sources on the premise of ensuring soil thermal balance. Different systems are reasonably coordinated according to their respective characteristics to achieve optimal utilization of energy, reduce the overall operating costs of the system, and improve energy efficiency.

[0086] Figure 2 It is an exemplary flow chart of a composite energy system energy efficiency evaluation method shown in some embodiments of this specification, including: Data collection: Detailed collection of operating data of ground source heat pump system, chiller system, and air source heat pump system to obtain parameters such as energy consumption and output of each system. Modeling and calculation: Establish an accurate mathematical model based on the characteristics of each system. The model comprehensively considers the energy consumption of various equipment and pumps in the system to participate in the calculation. Index calculation: Apply the collected data to the model, and calculate to obtain the efficiency indicators of each system, such as EER, COP, etc. Comprehensive evaluation: Comprehensively integrate the indicators of each system and compare them with the standards to judge the overall energy-saving effect of the system. Dynamic optimization: Continuously collect data, calculate and evaluate to achieve closed-loop system optimization and continuously improve energy efficiency.

[0087] Comprehensive operation energy efficiency EER of chiller system c The calculation of the annual energy efficiency ratio of the current high-efficiency refrigeration room follows the calculation formula:

[0088]

[0089] Among them, Q c0 Indicates the cumulative cooling capacity of the chiller in the cooling season; W ch Indicates the cumulative power consumption of the chiller in the cooling season; W chp Indicates the cumulative power consumption of the chilled water pump during the cooling season; W cp Indicates the cumulative power consumption of the cooling water pump in the cooling season; W ct Indicates the cumulative power consumption of the cooling tower during the cooling season;

[0090] Comprehensive cooling operation energy efficiency EER of ground source heat pump system g and heating comprehensive operation energy efficiency COP g Calculation:

[0091]

[0092] Among them, Q gc Indicates the cumulative cooling capacity of the ground source heat pump unit in the cooling season; W ghp1 Indicates the cumulative power consumption of the ground source heat pump unit in the cooling season; W up1 Indicates the cumulative power consumption of the user-side water pump in the cooling season; W gp1 Indicates the cumulative power consumption of the underground water pump during the cooling season;

[0093] Comprehensive heating operation efficiency COP of ground source heat pump system g Calculated by the following formula:

[0094]

[0095] Among them, Q gh Indicates the cumulative heat supply of the ground source heat pump unit in the heating season; W ghp2 Indicates the cumulative power consumption of the ground source heat pump unit during the heating season; W up2 Indicates the cumulative power consumption of the user-side water pump during the heating season; W gp2 Indicates the cumulative power consumption of the underground water pump during the heating season;

[0096] Comprehensive refrigeration operation energy efficiency (EER) of air source heat pump system a and heating comprehensive operation energy efficiency COP a The calculation of is as follows:

[0097]

[0098] Among them, Q ac Indicates the cumulative cooling capacity of the air source heat pump unit in the cooling season; W ahp1 Indicates the cumulative power consumption of the air source heat pump unit in the cooling season; W aup1 Indicates the cumulative power consumption of the user-side water pump during the cooling season;

[0099] Comprehensive heating operation energy efficiency COP of air source heat pump system a Calculated by the following formula:

[0100]

[0101] Among them, Q ah Indicates the cumulative heating capacity of the air source heat pump unit during the heating season; W ahp2 Indicates the cumulative power consumption of the air source heat pump unit during the heating season; W aup2 Indicates the cumulative power consumption of the user-side water pump during the heating season;

[0102] At present, the evaluation of the comprehensive energy efficiency of building cold and heat source systems is mainly focused on high-efficiency refrigeration rooms (chiller systems), while there are few studies on the comprehensive operation energy efficiency evaluation of ground source heat pump systems and air source heat pump systems. The energy consumption simulation calculation of high-efficiency operation conditions is performed for the chiller system, ground source heat pump system and air-conditioning source heat pump system respectively. For refrigeration or heat pump systems, the comprehensive energy efficiency is the ratio of the system's cumulative cooling capacity or heating capacity to the system's cumulative electricity consumption. This application provides a calculation formula for the operating energy consumption of equipment such as chillers (heat pumps), water pumps and cooling towers, which can more accurately simulate and calculate the energy consumption of the composite energy system throughout the year.

[0103] Instantaneous power consumption of chiller (heat pump) unit P i It can be calculated by the following formula:

[0104] Refrigeration conditions:

[0105]

[0106] Among them, P i Indicates the instantaneous power consumption of the chiller (heat pump), kW; Q i Indicates the instantaneous cooling (heating) capacity of the chiller (heat pump), kW; EER i Indicates the instantaneous refrigeration energy efficiency ratio of the chiller (heat pump); COP i Indicates the instantaneous heating coefficient of the heat pump unit.

[0107] For chillers and ground source heat pumps, the impact on EER i (COP i ) factors include the unit load ratio r, condenser outlet water temperature t cs and evaporator outlet water temperature tes , the calculation formula is as follows:

[0108] EER i =(A1r 3 +B1r 2 +C1r+D1)×[1-0.03×(t cs -t cc )]×[1+0.02×(t es -t ec )]

[0109] Among them, A1, B1, C1 and D1 represent the coefficients of the EER fitting formula for the partial load of the chiller or heat pump unit in the cooling condition; t cs Indicates the actual working condition outlet water temperature of the condenser of the chiller or heat pump unit; t cc Indicates the outlet water temperature of the chiller or heat pump unit condenser under the refrigeration design condition; t es Indicates the actual working condition outlet water temperature of the evaporator of the chiller or heat pump unit; t ec Indicates the outlet water temperature of the evaporator of the chiller or heat pump unit under the refrigeration design condition;

[0110] Instantaneous heating efficiency COP of ground source heat pump system i Calculated by the following formula:

[0111] COP i =(E1r 3 +F1r 2 +G1r+H1)×[1-0.03×(t cs -t ch )]×[1+0.02×(t es -t eh )]

[0112] Among them, E1, F1, G1 and H1 represent the coefficients of the partial load COP fitting formula of the heat pump unit under heating condition; r represents the load ratio; t cs Indicates the actual working condition outlet water temperature of the condenser of the chiller or heat pump unit; t ch Indicates the outlet water temperature of the heat pump unit condenser under heating design condition; t es Indicates the actual working condition outlet water temperature of the evaporator of the chiller or heat pump unit; t eh Indicates the outlet water temperature of the heat pump unit evaporator under heating design conditions;

[0113]

[0114] Where n represents the number of chillers or heat pumps in operation; Q0 represents the cooling capacity or heating capacity of the chiller or heat pump under the design conditions; Q i Indicates the instantaneous cooling capacity or heating capacity of the chiller or heat pump unit;

[0115] Instantaneous cooling energy efficiency ratio (EER) of air source heat pump system ai Calculated by the following formula:

[0116] EER ai =(A2t w 3 +B2t w 2 +C2t w +D2)×[1+0.02×(t es -t ec )]

[0117] Among them, A2, B2, C2 and D2 represent the fitting formula coefficients of the unit's cooling condition EER changing with outdoor temperature; t es Indicates the actual working condition outlet water temperature of the evaporator of the chiller or heat pump unit; t ec Indicates the outlet water temperature of the evaporator of the chiller or heat pump unit under the design refrigeration condition; t w Indicates the outdoor air dry bulb temperature;

[0118] Instantaneous heating efficiency COP of air source heat pump system ai Calculated by the following formula:

[0119] COP ai =(E2t w 3 +F2t w 2 +G2t w +H2)×[1-0.03×(t cs -t ch )]

[0120] Among them, E2, F2, G2 and H2 represent the coefficients of the fitting formula that changes with the outdoor temperature; t w Indicates the outdoor air dry bulb temperature; t cs Indicates the actual working condition outlet water temperature of the condenser of the chiller or heat pump unit; t ch Indicates the outlet water temperature of the heat pump unit condenser under heating design conditions;

[0121] Instantaneous power of the pump N w The calculation is as follows. The frequency of the water pump is generally 50Hz, and the frequency conversion water pump can reduce the frequency to 30Hz at the lowest. The flow rate is proportional to the frequency, so the minimum flow rate under the frequency conversion condition is 0.6 times the design flow rate of the water pump. The instantaneous power of the water pump is calculated by the following formula:

[0122]

[0123] Among them, N w Indicates the instantaneous power of the water pump, kW; G wIndicates the instantaneous flow rate of the water pump, m3 / h; G w0 Indicates the design flow rate of the pump, m3 / h; N w0 Indicates the nominal power of the water pump motor, kW.

[0124] Instantaneous power of cooling tower fan N a It depends on the air volume or speed of the fan. According to relevant literature, the simplified algorithm for the relationship between the heat dissipation of the cooling tower and parameters such as cooling water flow and cooling tower air volume is as follows:

[0125]

[0126] Among them, Q rej Indicates the heat dissipation of the cooling tower, kW; G w Indicates the cooling water mass flow rate, kg / s; G a Indicates air mass flow rate, kg / s; t wi Indicates the cooling tower water supply temperature, °C; t wb Indicates the wet bulb temperature of air, ℃.

[0127] According to the above formula, calculate the instantaneous air volume G a , the cooling tower fan power N can be calculated a Similar to the water pump, the fan frequency can be reduced to 30Hz, so:

[0128]

[0129] Among them, N a Indicates the instantaneous power of the fan, kW; G a Indicates the instantaneous air volume of the fan, kg / s; G a0 Indicates the fan design air volume, kg / s; N a0 Indicates the nominal power of the fan, kW.

[0130] The multi-energy complementary energy station based on ground source heat pump is mainly suitable for cold areas and areas with hot summer and cold winter. Taking into account the load characteristics of different building types, the energy consumption simulation of efficient operation of cold and heat source systems of five common public buildings such as offices, hotels, shopping malls, hospitals and schools is carried out respectively. In addition, for chiller systems and ground source heat pump systems, the energy efficiency of screw units and centrifugal units is quite different, and it is also necessary to analyze the cases where the capacity of a single unit is less than 1758kW (500RT) and greater than or equal to 1758kW (500RT).

[0131] Taking a certain city in cold regions as an example, the comprehensive energy efficiency of chiller system, ground source heat pump system and air source heat pump system is summarized in Tables 1 to 3:

[0132] Table 1 Comprehensive energy efficiency of chiller system in cold regions

[0133]

[0134] Table 2 Comprehensive energy efficiency of ground source heat pump system in cold areas

[0135]

[0136] Table 3 Comprehensive energy efficiency of air source heat pump system in cold regions

[0137] Building Types Office hotel shopping mall Hospital School <![CDATA[EER a ]]> 3.71 3.52 3.64 3.67 3.72 <![CDATA[COP a ]]> 2.74 2.79 2.63 2.80 2.76

[0138] Taking a certain city as an example, the comprehensive energy efficiency of the chiller system, ground source heat pump system and air source heat pump system in the hot summer and cold winter area is summarized in Table 4 to Table 6:

[0139] Table 4 Comprehensive energy efficiency of chiller system in hot summer and cold winter areas

[0140]

[0141] Table 5 Comprehensive energy efficiency of ground source heat pump system in hot summer and cold winter areas

[0142]

[0143] Table 6 Comprehensive energy efficiency of air source heat pump system in hot summer and cold winter areas

[0144] Building Types Office hotel shopping mall Hospital School <![CDATA[EER a ]]> 3.64 3.59 3.62 3.58 3.73 <![CDATA[COP a ]]> 2.82 3.01 2.58 3.01 2.80

[0145] In order to simplify the comprehensive energy efficiency evaluation standard, the comprehensive energy efficiency of the composite energy system is weighted according to the building type, and the distribution ratio of the completed area of ​​typical public buildings in my country in recent years is used as the weight coefficient. The calculation formula is as follows:

[0146] The comprehensive cooling energy efficiency ratio EER is calculated by the following formula:

[0147]

[0148] Among them, EER bg Represents the comprehensive cooling energy efficiency ratio of the office building cooling system; EER jd Represents the comprehensive cooling energy efficiency ratio of the hotel building refrigeration system; EER sc Indicates the comprehensive refrigeration energy efficiency ratio of the shopping mall building refrigeration system; EER yy Represents the comprehensive cooling energy efficiency ratio of the hospital building refrigeration system; EER xx represents the comprehensive refrigeration energy efficiency ratio of the school building refrigeration system; p bg represents the proportion of office building area; p jd represents the proportion of hotel building area; p sc represents the proportion of shopping mall building area; p yy represents the proportion of hospital building area; p xx It indicates the proportion of school building area;

[0149] The comprehensive heating efficiency ratio COP is calculated by the following formula:

[0150]

[0151] Among them, COP bg Represents the comprehensive heating energy efficiency ratio of the office building heat pump system; COP jd Indicates the comprehensive heating energy efficiency ratio of the hotel building heat pump system; COP sc Indicates the comprehensive heating energy efficiency ratio of the heat pump system of the shopping mall building; COP yy Represents the comprehensive heating energy efficiency ratio of the hospital building heat pump system; COP xx represents the comprehensive heating energy efficiency ratio of the school building heat pump system; p bg represents the proportion of office building area; p jd represents the proportion of hotel building area; p sc represents the proportion of shopping mall building area; p yy represents the proportion of hospital building area; p xx It indicates the proportion of school building area;

[0152] According to relevant statistical data, in a certain year, shopping malls accounted for 29% of the completed area of ​​public buildings, office buildings accounted for 21%, schools accounted for 20%, hospitals and hotels accounted for 7% and 3% respectively. Based on this weight, the calculated comprehensive energy efficiency of the composite energy system is shown in Table 7:

[0153] Table 7 Comprehensive energy efficiency of different composite energy system forms

[0154]

[0155] Different standards and specifications have different provisions for the energy efficiency rating of high-efficiency refrigeration rooms, and no basis for the energy efficiency rating is given. Based on the building thermal zoning indicators and the outdoor wet-bulb temperature distribution, the relevant research selected the outdoor average wet-bulb temperature in the cooling season as the zoning indicator for the energy efficiency ratio evaluation zoning of the refrigeration room system, adopted four energy efficiency ratio graded cold source systems, constructed multiple energy efficiency ratio calculation models for refrigeration room systems, and obtained the energy efficiency ratio grading evaluation standard for high-efficiency refrigeration room systems.

[0156] Taking into account the scientificity, rationality and universality of energy efficiency grading evaluation, combined with the above comprehensive energy efficiency simulation results, the energy efficiency level of the chiller system follows the energy efficiency ratio level of the high-efficiency refrigeration room system in cold areas and hot summer and cold winter areas, as shown in Table 8:

[0157] Table 8 Energy efficiency rating of chiller system

[0158]

[0159]

[0160] By comparing the energy efficiency simulation results of the chiller system with the energy efficiency level of the chiller system in the above table, the energy efficiency levels of the ground source heat pump system and the air source heat pump system are calculated, as shown in Table 9 and Table 10:

[0161] Table 9 Energy efficiency rating of ground source heat pump system

[0162]

[0163] Table 10 Energy efficiency rating of air heat pump system

[0164]

[0165] For the composite energy system combining the above three energy sources, the system energy efficiency level should be dynamically adjusted according to the energy supply changes of different composite energy systems. The calculation formula is as follows:

[0166] Refrigeration Energy Efficiency Limit EER s,n Calculated by the following formula:

[0167]

[0168] Among them, EER s,n Indicates the nth level of cooling energy efficiency limit of the composite energy system; EER c,n Indicates the nth level refrigeration energy efficiency limit of the chiller system; Q c1 Indicates the cumulative cooling capacity of the chiller system; EER g,n Indicates the nth level refrigeration energy efficiency limit of the ground source heat pump system; Q g1 Indicates the cumulative cooling capacity of the ground source heat pump system; EER a,n Indicates the cumulative cooling capacity of the air source heat pump system; Q a1 Indicates the cumulative cooling capacity of the air source heat pump system;

[0169] Heating energy efficiency limit COP s,n Calculated by the following formula:

[0170]

[0171] Among them, COP s,n Indicates the nth level heating energy efficiency limit of the composite energy system; COP g,n Indicates the nth level heating energy efficiency limit of the ground source heat pump system; Q g2 Indicates the cumulative heat supply of the ground source heat pump system; COP a,n Indicates the nth level heating energy efficiency limit of the air source heat pump system; Q a2 Indicates the cumulative heating supply of the air source heat pump system;

[0172] For municipal thermal / gas boiler systems, since it is impossible to use energy efficiency indicators for evaluation like refrigeration (heat pump) systems, there is no unified evaluation standard in the industry as a theoretical support for the winter heating operation conditions of energy stations. Therefore, the comprehensive cost-effectiveness CER (Cost Effectiveness Ratio) evaluation indicator is proposed, which is defined as follows:

[0173]

[0174] Among them, CER represents the comprehensive cost-effectiveness of the composite energy system, RMB / kWh; C represents the energy supply cost of the composite energy system, RMB; Q represents the energy supply of the composite energy system, kWh; C e represents the electricity cost of the composite energy system, RMB; C h represents the heating cost of the composite energy system (municipal heating system), RMB; C g Represents the operating gas cost of the composite energy system (gas boiler system), RMB.

[0175] Most cities in my country adopt a time-of-use electricity price policy. The electricity price in a certain city will be slightly adjusted every month. Table 11 shows the electricity price in a certain district of a certain city in a certain year:

[0176] Table 11 Time-of-day electricity prices in a certain city and district in July 2022

[0177]

[0178]

[0179] Note: Peak electricity prices are implemented from July to August.

[0180] The calculation formula for the operating electricity cost of the composite energy system is as follows:

[0181]

[0182] Wherein, t1 represents the time when the calculation starts (starting from 0:00 on January 1st), h; t2 represents the time when the calculation ends (starting from 0:00 on January 1st), h; W i represents the power consumption of the composite energy system in the i-th hour, kWh; e i Represents the electricity price at the i-th hour, yuan / kWh.

[0183] The municipal heating system adopts energy consumption index for billing, and the unit price is temporarily calculated at 98 yuan / GJ, as follows:

[0184]

[0185] Among them, H i represents the heat exchanged by the municipal thermal panel in the i-th hour, GJ; r irepresents the unit price of municipal heat in the i-th hour (fixed value, price changes are not considered for the time being), RMB / GJ; Q i It represents the heating amount provided by the municipal thermal system in the i-th hour, kWh.

[0186] According to the non-residential pipeline natural gas sales price list of a certain city, the heating season price of heating and cooling gas in the six urban districts is 2.88 yuan / Nm 3 The gas cost of operating a gas boiler system is calculated as follows:

[0187]

[0188] Among them, B i Indicates the gas consumption of the gas boiler in the i-th hour, Nm3; g i represents the natural gas unit price at the i-th hour (fixed value, price changes are not considered for the time being), RMB / Nm3; Q i represents the heat supply of the gas boiler system in the i-th hour, kWh; q g Indicates the calorific value of natural gas (8500kCal / Nm 3 , that is 35589.5kJ / Nm 3 ), kJ / Nm 3 ; η b Indicates the thermal efficiency of the gas boiler, which is 93%.

[0189] Based on the simulation calculation results of the comprehensive energy consumption of the composite energy system, the comprehensive operating cost-effectiveness of different composite energy systems is further calculated, and the cost-effectiveness calculation of the municipal thermal and gas boiler systems is added.

[0190] Taking a certain city in cold regions as an example, the comprehensive cost-effectiveness of the chiller system, ground source heat pump system, air source heat pump system, municipal heating system and gas boiler system is summarized in Tables 12 to 15:

[0191] Table 12 Comprehensive cost-effectiveness of chiller systems in cold regions

[0192]

[0193] Table 13 Comprehensive cost-effectiveness of ground source heat pump system in cold regions

[0194]

[0195] Table 14 Comprehensive cost-effectiveness of air source heat pump system in cold regions

[0196] Building Types Office hotel shopping mall Hospital School <![CDATA[CER a，c ]]> 0.28 0.29 0.29 0.27 0.27 <![CDATA[CER a，h ]]> 0.35 0.33 0.37 0.31 0.35

[0197] Table 15 Comprehensive cost-effectiveness of municipal thermal / gas boiler systems in cold regions

[0198] Building Types Office hotel shopping mall Hospital School <![CDATA[CER h ]]> 0.37 0.37 0.38 0.37 0.38 <![CDATA[CER b ]]> 0.33 0.33 0.33 0.33 0.33

[0199] Taking a certain city as an example, the comprehensive cost-effectiveness of the chiller system, ground source heat pump system, air source heat pump system, municipal heating system and gas boiler system in the hot summer and cold winter area is summarized as shown in Tables 16 to 19:

[0200] Table 16 Comprehensive cost-effectiveness of chiller systems in hot summer and cold winter regions

[0201]

[0202] Table 17 Comprehensive cost-effectiveness of ground source heat pump system in hot summer and cold winter areas

[0203]

[0204] Table 18 Comprehensive cost-effectiveness of air source heat pump system in hot summer and cold winter areas

[0205] Building Types Office hotel shopping mall Hospital School <![CDATA[CER a，c ]]> 0.28 0.28 0.29 0.29 0.27 <![CDATA[CER a，h ]]> 0.33 0.31 0.37 0.33 0.33

[0206] Table 19 Comprehensive cost-effectiveness of municipal thermal / gas boiler systems in hot summer and cold winter regions

[0207] Building Types Office hotel shopping mall Hospital School <![CDATA[CER h ]]> 0.37 0.37 0.38 0.37 0.37 <![CDATA[CER b ]]> 0.33 0.33 0.35 0.33 0.33

[0208] The operating cost-effectiveness (CER) of the composite energy system is calculated by the following formula:

[0209]

[0210] Among them, CER bg Indicates the comprehensive cost-effectiveness ratio of the cooling and heating source system of an office building; CER jd Indicates the comprehensive cost-effectiveness ratio of the hotel building's cooling and heating system; CER sc Indicates the comprehensive cost-effectiveness ratio of the cooling and heating source system of the shopping mall building; CER yy Represents the comprehensive cost-effectiveness ratio of the cooling and heating source system of the hospital building; CER xx Represents the comprehensive cost-effectiveness ratio of the school building's cooling and heating source system; p bg represents the proportion of office building area; p jd represents the proportion of hotel building area; p sc represents the proportion of shopping mall building area; p yy represents the proportion of hospital building area; p xx It indicates the proportion of school building area;

[0211] After weighted calculation, the comprehensive cost-effectiveness of different composite energy systems in cold regions and hot-summer-cold-winter regions is shown in Table 20:

[0212] Table 20 Comprehensive cost-effectiveness of different composite energy system forms

[0213]

[0214] The cost-effectiveness of a composite energy system is greatly affected by the electricity price, heat price or gas price of a specific project, and it is difficult to measure the operating economy of a composite energy system by formulating a unified cost-effectiveness grading standard. The research content of this application, on the one hand, proposes a cost-effectiveness calculation method to determine the operating cost level of a composite energy system; on the other hand, in a composite energy system with multi-energy coupling, a control strategy can be formulated to reduce the overall operating cost of the system by comparing the cost-effectiveness of different composite energy systems. The above simulation and calculation results of the cost-effectiveness of different composite energy systems can be used as a reference for specific projects.

[0215] According to the climate zones and installed capacity of the refrigeration system, the energy efficiency level limits of the chiller system are obtained, as shown in Table 21:

[0216] Table 21 Energy efficiency rating of chiller system

[0217]

[0218]

[0219] After simulation calculation, the comprehensive energy efficiency of high-efficiency computer rooms with different composite energy system forms was obtained, as shown in Table 22.

[0220] Table 22 Comprehensive energy efficiency of different composite energy system forms

[0221]

[0222] Energy efficiency limit EER of ground source heat pump system g,n , Energy efficiency limit COP of chiller system g,n Energy efficiency limit EER of air source heat pump system a,n , COP a,n Calculated by the following formulas:

[0223]

[0224]

[0225]

[0226]

[0227] Among them, EER c,n Indicates the nth level refrigeration energy efficiency limit of the chiller system; EER g Indicates the comprehensive cooling energy efficiency of the ground source heat pump system; EER c Indicates the comprehensive operating energy efficiency of the chiller system; COP g Indicates the comprehensive heating operation energy efficiency of the ground source heat pump system; EERa Indicates the comprehensive refrigeration operation energy efficiency of the air source heat pump system; COP a It represents the comprehensive heating operation energy of the air source heat pump system.

[0228] Taking the ground source heat pump system as an example, in cold areas, the installed capacity is <1758kW, and the comprehensive energy efficiency EER of the high-efficiency computer room cooling is g Correspondingly, in cold regions, with installed capacity <1758kW, the comprehensive energy efficiency EER of high-efficiency computer room cooling is c It is 5.44, and its level 3, level 2, level 1 and leading energy efficiency limits are 4.0, 4.4, 4.7 and 5.0 respectively; calculated according to the above formula, in cold areas, with installed capacity <1758kW, the energy efficiency limits of ground source heat pump system refrigeration level 3, level 2, level 1 and leading level are 3.7, 4.1, 4.4 and 4.6 respectively (round up the first decimal place).

[0229] According to the above method, the energy efficiency level limits of the ground source heat pump system and the air source heat pump system are calculated, as shown in Table 23 and Table 24.

[0230] Table 23 Energy efficiency rating of ground source heat pump system

[0231]

[0232] Table 24 Energy efficiency rating of air heat pump system

[0233]

[0234] The energy saving rate is usually used to evaluate the energy saving effect of the transformation system, and its definition is as follows:

[0235]

[0236] Among them, η e Indicates energy saving rate; E b Indicates the energy consumption before system transformation, kWh; E a Indicates the energy consumption of the system after transformation, kWh.

[0237] The energy saving rate evaluation index is proposed to evaluate the energy saving of energy station systems using energy saving algorithms compared with conventional energy station systems. The energy saving rate benchmark is set at 10%, and we strive to achieve an excellent energy saving target of 15%. However, the operating energy consumption of conventional energy stations that do not use energy saving algorithms is difficult to determine through simulation calculations. On the one hand, energy consumption simulation is carried out under certain assumptions and simplified premises, and its calculation results cannot be directly used as the benchmark value for energy saving rate calculation; on the other hand, even for conventional energy station systems with the same system form and equipment selection, there are still differences in operating strategies due to different project requirements.

[0238] The energy efficiency grading evaluation standard for high-efficiency computer room systems explains the principles for dividing energy efficiency levels. The three-level energy efficiency means that all major energy-consuming equipment meets the basic requirements of the current energy-saving standards, and variable frequency water pumps and cooling towers are reasonably selected, and the control logic of high-efficiency refrigeration rooms is adopted. Energy efficiency deviation corrections not considered in the theoretical model are added. Under this condition, the actual year-round operating energy efficiency ratio that can be achieved is regarded as the entry level of high-efficiency refrigeration rooms. This energy saving rate is used to evaluate the energy-saving effect of the multi-energy coupling energy station system using high-efficiency energy-saving algorithms and optimized control strategies. For conventional energy stations that do not use energy-saving algorithms and control strategies, the design conditions and operating conditions corresponding to the three-level energy efficiency of the high-efficiency computer room system can be considered, that is, when calculating the energy saving rate, the three-level energy efficiency limit value of the composite energy system is selected as the benchmark value.

[0239] Energy saving rate η in refrigeration condition ec Calculated by the following formula:

[0240]

[0241] Among them, EER s,3 Indicates the energy efficiency limit value of the third level of refrigeration in the composite energy system; EER s Indicates the actual energy efficiency of cooling in a composite energy system;

[0242] Energy saving rate η of heating condition eh Calculated by the following formula:

[0243]

[0244] Among them, COP s,3 Indicates the three-level energy efficiency limit value of heating of the composite energy system; COP s Indicates the actual energy efficiency of heating of the composite energy system.

[0245] The energy saving rate calculation method of the present application can, firstly, avoid the complicated energy consumption simulation process and eliminate the influence of uncertainty in the calculation results; secondly, it adopts an average and unified benchmark value, which is simple to calculate and relatively scientific and reasonable; finally, the calculation method can more accurately reflect the energy saving effect of the studied energy-saving algorithm and control strategy in the application of the energy station system.

[0246] With reference to the calculation method of the energy efficiency of high-efficiency refrigeration room operation in relevant domestic and foreign research, the comprehensive energy efficiency of the energy station is the ratio of the cumulative cooling (heating) supply to the cumulative electricity consumption; for chillers, ground source heat pumps and air source heat pump systems, two climate zones, two installed capacities and five building types are considered, and the efficient operation energy consumption simulation of the system is carried out respectively. According to the energy consumption results and the energy efficiency grading standards in relevant literature, the energy efficiency grading of the single composite energy system is determined; for coupled composite energy systems, the energy efficiency evaluation grading standards are determined by weighted average calculation based on the energy supply proportion of different energy forms.

[0247] Since municipal thermal / gas boiler systems cannot be evaluated using energy efficiency indicators like refrigeration (heat pump) systems, a comprehensive cost-effectiveness evaluation index is proposed, which is defined as the ratio of cumulative operating costs to cumulative cooling (heating) supply. Considering the fluctuations in energy prices, it is impossible to formulate a unified cost-effectiveness grading standard. The introduction of cost-effectiveness indicators can reflect the operating cost level of the system on the one hand, and on the other hand, it can be used as a target parameter for relevant control strategies in multi-energy coupling systems;

[0248] Based on the basic condition analysis of the three-level energy efficiency in the operating energy efficiency, the three-level energy efficiency limit value is used as the operating energy efficiency of the conventional energy station system in the calculation of the energy saving rate. This energy saving rate calculation method avoids the error caused by simulation calculation and can more accurately reflect the energy saving benefits of energy saving algorithms and control strategies.

[0249] The above schematically describes the invention and its implementation methods, which is not restrictive. Without departing from the spirit or basic features of the invention, the invention can be implemented in other specific forms. What is shown in the accompanying drawings is only one of the implementation methods of the invention. The actual structure is not limited thereto, and any figure mark in the claims should not limit the claims involved. Therefore, if a person of ordinary skill in the art is inspired by it, and does not deviate from the purpose of the invention, and does not creatively design a structural method and embodiment similar to the technical solution, they should all fall within the scope of protection of this patent. In addition, the word "including" does not exclude other elements or steps, and the word "one" before the element does not exclude the inclusion of "multiple" elements. The multiple elements stated in the product claim can also be implemented by one element through software or hardware. The words first, second, etc. are used to indicate names, and do not indicate any specific order.

Claims

1. A composite energy system energy efficiency evaluation method, comprising: The operating parameters of the composite energy system are collected respectively. The composite energy system includes a ground source heat pump system and an auxiliary coupling system. The auxiliary coupling system includes a chiller system, an air source heat pump system and a gas boiler system. Based on the collected operating parameters, the energy efficiency indicators of the ground source heat pump system, chiller system, air source heat pump system and gas boiler system are calculated respectively; Calculate the energy efficiency and cost efficiency of the composite energy system based on the collected operating parameters; Calculate the comprehensive system operation energy efficiency of the composite energy system based on the calculated energy efficiency indicators of the ground source heat pump system, chiller system, air source heat pump system and gas boiler system; Calculate the energy saving rate of the composite energy system according to the calculated comprehensive system operation energy efficiency of the composite energy system; Energy efficiency evaluation of the composite energy system is conducted based on the calculated operating energy efficiency, operating cost efficiency, comprehensive system operating energy efficiency and energy saving rate; The operating parameters include: Ground source heat pump system: cumulative cooling capacity of heat pump unit in cooling season Q gc , Cumulative power consumption of heat pump unit in cooling season W ghp1 , the cumulative heating supply of heat pump units in the heating season Q gh , Cumulative power consumption of heat pump units in heating season W ghp2 Cumulative power consumption of underground water pump in heating season W gp2 ; Cumulative power consumption of user-side water pump in cooling season W up1 , Cumulative power consumption of underground water pump in cooling season W gp1 , Cumulative power consumption of water pumps on the user side during the heating season W up2 , Cumulative power consumption of user-side water pumps in cooling season W aup1 The cumulative power consumption of the user-side water pump in the heating season is W aup2 ; Chiller system: Accumulated cooling capacity of chiller in cooling season Q c0 , Cumulative power consumption of chillers in cooling season W ch , Cumulative power consumption of chilled water pump in cooling season W chp , Cooling water pump cumulative power consumption in cooling season W cp And the cumulative power consumption of cooling tower in cooling season W ct ; Air source heat pump system: cumulative cooling capacity of heat pump unit in cooling season Q ac , Cumulative power consumption of heat pump unit in cooling season W ahp1 , the cumulative heating supply of heat pump units in the heating season Q ah , Cumulative power consumption of heat pump units in heating season W ahp2 ; Operational energy efficiency includes: Comprehensive operation energy efficiency EER of chiller system c , Comprehensive refrigeration operation energy efficiency EER of ground source heat pump system g , Comprehensive heating operation efficiency COP of ground source heat pump system g , Comprehensive refrigeration operation energy efficiency EER of air source heat pump system a , Comprehensive heating operation energy efficiency COP of air source heat pump system a , instantaneous cooling energy efficiency ratio EER of chillers or heat pump units i , Instantaneous heating coefficient COP of ground source heat pump system i , Instantaneous cooling capacity EER of air source heat pump system ai And the instantaneous heating coefficient COP of the air source heat pump system ai ; Comprehensive operation energy efficiency EER of chiller system c Calculated by the following formula: Among them, Q c0 Indicates the cumulative cooling capacity of the chiller in the cooling season; W ch Indicates the cumulative power consumption of the chiller in the cooling season; W chp Indicates the cumulative power consumption of the chilled water pump during the cooling season; W cp Indicates the cumulative power consumption of the cooling water pump in the cooling season; W ct Indicates the cumulative power consumption of the cooling tower during the cooling season; Comprehensive cooling operation energy efficiency EER of ground source heat pump system g Calculated by the following formula: Among them, Q gc Indicates the cumulative cooling capacity of the ground source heat pump unit in the cooling season; W ghp1 Indicates the cumulative power consumption of the ground source heat pump unit in the cooling season; W up1 Indicates the cumulative power consumption of the user-side water pump in the cooling season; W gp1 Indicates the cumulative power consumption of the underground water pump during the cooling season; Comprehensive heating operation efficiency COP of ground source heat pump system g Calculated by the following formula: Among them, Q gh Indicates the cumulative heat supply of the ground source heat pump unit in the heating season; W ghp2 Indicates the cumulative power consumption of the ground source heat pump unit during the heating season; W up2 Indicates the cumulative power consumption of the user-side water pump during the heating season; W gp2 Indicates the cumulative power consumption of the underground water pump during the heating season; Comprehensive refrigeration operation energy efficiency (EER) of air source heat pump system a Calculated by the following formula: Among them, Q ac Indicates the cumulative cooling capacity of the air source heat pump unit in the cooling season; W ahp1 Indicates the cumulative power consumption of the air source heat pump unit in the cooling season; W aup1 Indicates the cumulative power consumption of the user-side water pump during the cooling season; Comprehensive heating operation energy efficiency COP of air source heat pump system a Calculated by the following formula: Among them, Q ah Indicates the cumulative heating capacity of the air source heat pump unit during the heating season; W ahp2 Indicates the cumulative power consumption of the air source heat pump unit during the heating season; W aup2 Indicates the cumulative power consumption of the user-side water pump during the heating season; Instantaneous cooling energy efficiency ratio EER of chiller or heat pump unit i Calculated by the following formula: HONOR i =(A1r 3 +B1r 2 +C1r+D1)×[1-0.03×(t cs -t cc )]×[1+0.02×(t es -t ec )] Among them, A1, B1, C1 and D1 represent the coefficients of the EER fitting formula for the partial load of the chiller or heat pump unit in the cooling condition; t cs Indicates the actual working condition outlet water temperature of the condenser of the chiller or heat pump unit; t cc Indicates the outlet water temperature of the chiller or heat pump unit condenser under the refrigeration design condition; t es Indicates the actual working condition outlet water temperature of the evaporator of the chiller or heat pump unit; t ec Indicates the outlet water temperature of the evaporator of the chiller or heat pump unit under the refrigeration design condition; Instantaneous heating efficiency COP of ground source heat pump system i Calculated by the following formula: COP i =(E1r 3 +F1r 2 +G1r+H1)×[1-0.03×(t cs -t ch )]×[1+0.02×(t es -t eh )] Among them, E1, F1, G1 and H1 represent the coefficients of the partial load COP fitting formula of the heat pump unit under heating condition; r represents the load ratio; t cs Indicates the actual working condition outlet water temperature of the condenser of the chiller or heat pump unit; t ch Indicates the outlet water temperature of the heat pump unit condenser under heating design condition; t es Indicates the actual working condition outlet water temperature of the evaporator of the chiller or heat pump unit; t eh Indicates the outlet water temperature of the heat pump unit evaporator under heating design conditions; Where n represents the number of chillers or heat pumps in operation; Q0 represents the cooling capacity or heating capacity of the chiller or heat pump under the design conditions; Q i Indicates the instantaneous cooling capacity or heating capacity of the chiller or heat pump unit; Instantaneous cooling energy efficiency ratio (EER) of air source heat pump system ai Calculated by the following formula: <h2 style=";text-align:left;direction:ltr">EER<h2 style=";text-align:left;direction:ltr"> ai <h2 style=";text-align:left;direction:ltr"> (A2t)<h2 style=";text-align:left;direction:ltr"> w <h2 style=";text-align:left;direction:ltr"> 3 <h2 style=";text-align:left;direction:ltr"> +B2t<h2 style=";text-align:left;direction:ltr"> w <h2 style=";text-align:left;direction:ltr"> 2 <h2 style=";text-align:left;direction:ltr"> +C2t<h2 style=";text-align:left;direction:ltr"> w <h2 style=";text-align:left;direction:ltr"> +D2)×[1+0.02×(t<h2 style=";text-align:left;direction:ltr"> es <h2 style=";text-align:left;direction:ltr"> -t<h2 style=";text-align:left;direction:ltr"> ec <h2 style=";text-align:left;direction:ltr"> )] Among them, A2, B2, C2 and D2 represent the fitting formula coefficients of the unit's cooling condition EER changing with outdoor temperature; t es Indicates the actual working condition outlet water temperature of the evaporator of the chiller or heat pump unit; t ec Indicates the outlet water temperature of the evaporator of the chiller or heat pump unit under the design refrigeration condition; t w Indicates the outdoor air dry bulb temperature; Instantaneous heating efficiency COP of air source heat pump system ai Calculated by the following formula: COP ai =(E2t w 3 +F2t w 2 +G2t w +H2)×[1-0.03×(t cs -t ch )] Among them, E2, F2, G2 and H2 represent the coefficients of the fitting formula that changes with the outdoor temperature; t w Indicates the outdoor air dry bulb temperature; t cs Indicates the actual working condition outlet water temperature of the condenser of the chiller or heat pump unit; t ch Indicates the outlet water temperature of the heat pump unit condenser under heating design conditions; Energy efficiency indicators include: Energy efficiency limit EER of ground source heat pump system g,n , Energy efficiency limit COP of chiller system g,n , Refrigeration Energy Efficiency Limit EER of Air Source Heat Pump System a,n and heating energy efficiency limit COP of air source heat pump system a,n , respectively calculated by the following formulas: Among them, EER c,n Indicates the nth level refrigeration energy efficiency limit of the chiller system; EER g Indicates the comprehensive cooling energy efficiency of the ground source heat pump system; EER c Indicates the comprehensive operating energy efficiency of the chiller system; COP g Indicates the comprehensive heating operation energy efficiency of the ground source heat pump system; EER a Indicates the comprehensive cooling operation energy efficiency of the air source heat pump system; COP a represents the comprehensive heating operation energy efficiency of the air source heat pump system; when n is 1, EER c,n The value range of n is 4.5 to 5; when n is 2, EER c,n The value range of n is 4.3 to 4.8; when n is 3, EER c,n The value range of is 3.9 to 4.4; Comprehensive system operation energy efficiency of hybrid energy systems including cooling energy efficiency limit value EER s,n and heating energy efficiency limit COP s,n ; Refrigeration Energy Efficiency Limit EER s,n Calculated by the following formula: Among them, EER s,n Indicates the nth level of cooling energy efficiency limit of the composite energy system; EER c,n Indicates the nth level refrigeration energy efficiency limit of the chiller system; Q c1 Indicates the cumulative cooling capacity of the chiller system; EER g,n Indicates the nth level refrigeration energy efficiency limit of the ground source heat pump system; Q g1 Indicates the cumulative cooling capacity of the ground source heat pump system; EER a,n Indicates the cumulative cooling capacity of the air source heat pump system; Q a1 represents the cumulative cooling capacity of the air source heat pump system; when n is 1, EER g,n The value range of EER is 3.7 to 4.9; when n is 2, g,n The value range of n is 3.5 to 4.4; when n is 3, EER g,n The value range of is 3.2 to 4.2; Heating energy efficiency limit COP s,n Calculated by the following formula: Among them, COP s,n Indicates the nth level heating energy efficiency limit of the composite energy system; COP g,n Indicates the nth level heating energy efficiency limit of the ground source heat pump system; Q g2 Indicates the cumulative heat supply of the ground source heat pump system; COP a,n Indicates the nth level heating energy efficiency limit of the air source heat pump system; Q a2 represents the cumulative heat supply of the air source heat pump system; when n is 1, COP a,n The value range of n is 2.5 to 3.2; when n is 2, COP a,n The value range of n is 2.3 to 3.1; when n is 3, COP a,n The value range is 2.1 to 2.

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2. The method for evaluating the energy efficiency of a composite energy system according to claim 1, characterized in that: The comprehensive cooling energy efficiency ratio EER is calculated by the following formula: Among them, EER bg Represents the comprehensive cooling energy efficiency ratio of the office building cooling system; EER jd Represents the comprehensive cooling energy efficiency ratio of the hotel building refrigeration system; EER sc Indicates the comprehensive refrigeration energy efficiency ratio of the shopping mall building refrigeration system; EER yy Represents the comprehensive cooling energy efficiency ratio of the hospital building refrigeration system; EER xx represents the comprehensive refrigeration energy efficiency ratio of the school building refrigeration system; p bg represents the proportion of office building area; p jd represents the proportion of hotel building area; p sc represents the proportion of shopping mall building area; p yy represents the proportion of hospital building area; p xx It indicates the proportion of school building area; The comprehensive heating efficiency ratio COP is calculated by the following formula: Among them, COP bg Represents the comprehensive heating energy efficiency ratio of the office building heat pump system; COP jd Indicates the comprehensive heating energy efficiency ratio of the hotel building heat pump system; COP sc Indicates the comprehensive heating energy efficiency ratio of the heat pump system of the shopping mall building; COP yy Represents the comprehensive heating energy efficiency ratio of the hospital building heat pump system; COP xx represents the comprehensive heating energy efficiency ratio of the school building heat pump system; p bg represents the proportion of office building area; p jd represents the proportion of hotel building area; p sc represents the proportion of shopping mall building area; p yy represents the proportion of hospital building area; p xx Indicates the proportion of school building area.

3. The method for evaluating energy efficiency of a composite energy system according to claim 1, characterized in that: The operating cost-effectiveness (CER) of the composite energy system is calculated by the following formula: Among them, CER bg Indicates the comprehensive cost-effectiveness ratio of the cooling and heating source system of an office building; CER jd Indicates the comprehensive cost-effectiveness ratio of the hotel building's cooling and heating system; CER sc Indicates the comprehensive cost-effectiveness ratio of the cooling and heating source system of the shopping mall building; CER yy Represents the comprehensive cost-effectiveness ratio of the cooling and heating source system of the hospital building; CER xx Represents the comprehensive cost-effectiveness ratio of the school building's cooling and heating source system; p bg represents the proportion of office building area; p jd represents the proportion of hotel building area; p sc represents the proportion of shopping mall building area; p yy represents the proportion of hospital building area; p xx Indicates the proportion of school building area.

4. The method for evaluating energy efficiency of a composite energy system according to claim 1, characterized in that: The energy saving rate of the composite energy system includes: energy saving rate of refrigeration condition η ec And the energy saving rate of heating condition η eh ; Among them, the energy saving rate of refrigeration condition η ec Calculated by the following formula: Among them, EER s,3 Indicates the energy efficiency limit value of the third level of refrigeration in the composite energy system; EER s Indicates the actual energy efficiency of cooling in a composite energy system; Among them, the energy saving rate of heating condition η eh Calculated by the following formula: Among them, COP s,3 Indicates the three-level energy efficiency limit value of heating of the composite energy system; COP s Indicates the actual energy efficiency of heating of the composite energy system.

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