Analysis method and related device for cascade utilization of waste heat of cold-heat-electricity integrated system of converter station

Abstract

The application discloses a waste heat cascade utilization analysis method of a cold heat and power integrated system of a converter station and related devices, determines the structure of a comprehensive energy system of the converter station, and constructs a form structure; according to the form structure, a waste heat cascade recovery mode of a refrigeration mode and a heating mode is analyzed, and a mixed-effect waste heat recovery mode is determined; according to the mixed-effect waste heat recovery mode, waste heat conversion analysis is carried out, and waste heat cascade utilization potential parameters are calculated; taking the maximum heat energy recovery amount and the maximum conversion energy efficiency as optimization targets, energy output analysis under different working condition modes is carried out according to preset energy output constraints and HVAC rated capacity constraints, and energy output characteristics are obtained; based on the energy output characteristics, an energy output domain performance critical curve is drawn, and a critical point energy efficiency value is analyzed. The application can solve the technical problems that the existing waste heat recovery mode is extensive, the refrigeration mode is single, and systematic modeling is lacking, resulting in poor actual effect of waste heat cascade utilization, and failing to carry out targeted adjustment and optimization.

Description

Technical Field

[0001] This application relates to the field of power system technology, and in particular to a method and related apparatus for analyzing the cascade utilization of waste heat in converter station integrated cooling, heating and power systems. Background Technology

[0002] As a core hub for power transmission, DC converter stations exhibit diverse energy consumption types, high load demands, and significant differences in timing characteristics, generally resulting in high energy consumption and source-load mismatch. Converter valves, as core equipment for AC-DC conversion, generate substantial power loss and waste heat during operation, requiring supporting cooling systems to ensure safe operation. Currently, converter stations mostly employ evaporative cooling and closed-loop cooling towers for heat dissipation, directly releasing low-temperature waste heat from the converter valve outlet. This not only wastes a significant amount of energy but also results in high water consumption and wastewater discharge, significantly increasing the operating costs and energy consumption of converter stations. Therefore, tapping into the waste heat resources within the station and achieving multi-energy synergistic optimization has become an urgent need for industry development.

[0003] Currently, waste heat utilization and combined cooling, heating, and power (CCHP) technologies in converter stations have gradually developed. Mainstream technologies include waste heat for hot water / steam production, heat lift technology, and absorption refrigeration technology. Among these, absorption refrigeration technology can convert industrial waste heat into cooling power. Coupled with converter valve evaporative cooling technology, it can both ensure equipment cooling and provide cooling for the entire station, demonstrating a high level of technological maturity. Simultaneously, CCHP systems are increasingly being applied in industrial settings, enabling the combined supply of electricity, heat, and cooling. Some solutions attempt to integrate waste heat with refrigeration and heating systems, exploring initial pathways for the resource utilization of waste heat.

[0004] However, existing technologies have significant drawbacks: First, the waste heat recovery method is crude, with waste heat from flue gas and cylinder liner water being recovered in series, which fails to deeply recover the heat from the flue gas and results in significant exergy losses, violating the principle of energy cascade utilization. Second, the refrigeration mode is singular, with single-effect or double-effect absorption refrigeration unable to match waste heat of different grades, resulting in a large amount of hot water waste heat not being effectively utilized. Third, there is a lack of systematic modeling methods, and the potential for cascade utilization of waste heat, energy output characteristics, and energy output domain laws of combined cooling, heating, and power systems are not clearly defined, making it impossible to balance system reliability and economy, and difficult to guide the planning and optimized operation of the converter station's integrated energy system. Summary of the Invention

[0005] This application provides a method and related apparatus for analyzing the cascade utilization of waste heat in a converter station integrated cooling, heating and power system. It addresses the shortcomings of existing technologies, such as crude waste heat recovery methods, single cooling modes, and lack of systematic modeling, which result in poor actual performance of existing cascade utilization of waste heat and the inability to make targeted adjustments and optimizations.

[0006] In view of this, the first aspect of this application provides a method for analyzing the cascade utilization of waste heat in a converter station integrated cooling, heating, and power system, including:

[0007] The structure of the integrated energy system in the converter station's integrated cooling, heating, and power system is determined, and the morphological structure of the integrated energy system is constructed.

[0008] Based on the aforementioned morphological structure, the waste heat cascade recovery mode in cooling and heating modes is analyzed to determine the mixed-effect waste heat recovery mode. The mixed-effect waste heat recovery mode uses the difference between the real-time load demand and the current waste heat output as the mode switching trigger condition.

[0009] Waste heat conversion analysis is performed based on the aforementioned mixed-effect waste heat recovery mode, and the potential parameters for the cascade utilization of waste heat are calculated. The potential parameters for the cascade utilization of waste heat include the total recovered waste heat.

[0010] Based on the waste heat cascade utilization potential parameters, the maximum heat recovery amount and the maximum conversion energy efficiency are configured as optimization objectives. Energy output analysis is performed under different operating conditions according to preset energy output constraints and HVAC rated capacity constraints to obtain energy output characteristics, which include cooling output and heating output.

[0011] Based on the energy output characteristics, a critical performance curve for the energy output domain is plotted, and the critical point energy efficiency value is analyzed.

[0012] Preferably, the analysis of the waste heat recovery mode in cooling and heating modes based on the morphological structure to determine the mixed-effect waste heat recovery mode, wherein the mixed-effect waste heat recovery mode uses the difference between the real-time load demand and the current waste heat output as the mode switching trigger condition, including:

[0013] Based on the aforementioned morphological structure, a single refrigeration unit is configured with a dual-source driven mixed-effect absorption refrigeration mode, which simultaneously realizes a single-effect refrigeration cycle and a dual-effect refrigeration cycle.

[0014] Based on the analysis of the waste heat recovery characteristics in the cooling and heating modes of the dual-source driven mixed absorption cooling mode, a high-temperature section power generation recovery mode and a low-temperature section waste water flow recovery mode are generated to obtain the mixed waste heat recovery mode.

[0015] A model of an electrically driven HVAC system is built, and the difference between the real-time load demand and the current waste heat output is calculated as the mode switching trigger condition to trigger mode switching.

[0016] Preferably, the waste heat conversion analysis is performed based on the mixed-effect waste heat recovery mode, and the waste heat cascade utilization potential parameters are calculated. These waste heat cascade utilization potential parameters include the total recovered waste heat, comprising:

[0017] Based on the aforementioned mixed-effect waste heat recovery mode, heat emission analysis is performed from multiple waste heat emission factors to obtain a waste heat calculation formula;

[0018] Based on the aforementioned waste heat calculation formula, the waste heat conversion path under the heating mode is analyzed, and the corresponding waste heat recovery is calculated.

[0019] Analyze the waste heat conversion characteristics under the refrigeration mode, calculate the combined cooling capacity and combined COP, and obtain the parameters of waste heat recovery in refrigeration.

[0020] Based on the parameters of the waste heat recovered from heating and the waste heat recovered from cooling, a quantitative analysis is performed to determine the potential parameters for the cascade utilization of waste heat.

[0021] Preferably, the optimization objective is to configure the maximum heat recovery and maximum conversion efficiency based on the waste heat cascade utilization potential parameters. Energy output analysis is performed under different operating conditions according to preset energy output constraints and HVAC rated capacity constraints to obtain energy output characteristics, including:

[0022] With the maximum heat recovery and maximum conversion efficiency as optimization objectives, the independent operation scenario and the grid-connected operation scenario are defined according to the relationship between power generation and power load, and a preset energy output constraint is constructed.

[0023] The energy output characteristics under different operating conditions are analyzed and calculated by combining the preset energy output constraints and HVAC rated capacity constraints.

[0024] The second aspect of this application provides a waste heat cascade utilization analysis device for a converter station integrated cooling, heating, and power system, comprising:

[0025] A morphological structure construction unit is used to determine the structure of the integrated energy system in the converter station's integrated cooling, heating and power system, and to construct the morphological structure of the integrated energy system.

[0026] The waste heat recovery analysis unit is used to analyze the waste heat cascade recovery mode in cooling mode and heating mode based on the morphological structure, and determine the mixed-effect waste heat recovery mode. The mixed-effect waste heat recovery mode uses the difference between the real-time load demand and the current waste heat output as the mode switching trigger condition.

[0027] The potential calculation unit is used to perform waste heat conversion analysis based on the mixed-effect waste heat recovery mode and calculate the waste heat cascade utilization potential parameters, which include the total recovered waste heat.

[0028] The energy output analysis unit is used to configure the maximum heat recovery amount and the maximum conversion energy efficiency as optimization targets based on the waste heat cascade utilization potential parameters, and to perform energy output analysis under different operating conditions according to preset energy output constraints and HVAC rated capacity constraints to obtain energy output characteristics, including cooling output and heating output.

[0029] The output energy efficiency analysis unit is used to plot the energy output domain performance critical curve based on the energy output characteristics and analyze the critical point energy efficiency value.

[0030] Preferably, the waste heat recovery analysis unit includes:

[0031] Based on the aforementioned morphological structure, a single refrigeration unit is configured with a dual-source driven mixed-effect absorption refrigeration mode, which simultaneously realizes a single-effect refrigeration cycle and a dual-effect refrigeration cycle.

[0032] Based on the analysis of the waste heat recovery characteristics in the cooling and heating modes of the dual-source driven mixed absorption cooling mode, a high-temperature section power generation recovery mode and a low-temperature section waste water flow recovery mode are generated to obtain the mixed waste heat recovery mode.

[0033] A model of an electrically driven HVAC system is built, and the difference between the real-time load demand and the current waste heat output is calculated as the mode switching trigger condition to trigger mode switching.

[0034] Preferably, the potential calculation unit includes:

[0035] Based on the aforementioned mixed-effect waste heat recovery mode, heat emission analysis is performed from multiple waste heat emission factors to obtain a waste heat calculation formula;

[0036] Based on the aforementioned waste heat calculation formula, the waste heat conversion path under the heating mode is analyzed, and the corresponding waste heat recovery is calculated.

[0037] Analyze the waste heat conversion characteristics under the refrigeration mode, calculate the combined cooling capacity and combined COP, and obtain the parameters of waste heat recovery in refrigeration.

[0038] Based on the parameters of the waste heat recovered from heating and the waste heat recovered from cooling, a quantitative analysis is performed to determine the potential parameters for the cascade utilization of waste heat.

[0039] Preferably, the energy output analysis unit includes:

[0040] With the maximum heat recovery and maximum conversion efficiency as optimization objectives, the independent operation scenario and the grid-connected operation scenario are defined according to the relationship between power generation and power load, and a preset energy output constraint is constructed.

[0041] The energy output characteristics under different operating conditions are analyzed and calculated by combining the preset energy output constraints and HVAC rated capacity constraints.

[0042] The third aspect of this application provides a waste heat cascade utilization analysis device for a converter station integrated cooling, heating and power system, the device including a processor and a memory;

[0043] The memory is used to store program code and transmit the program code to the processor;

[0044] The processor is used to execute the waste heat cascade utilization analysis method of the converter station integrated cooling, heating and power system described in the first aspect according to the instructions in the program code.

[0045] The fourth aspect of this application provides a computer-readable storage medium for storing program code for executing the waste heat cascade utilization analysis method of the converter station integrated cooling, heating and power system described in the first aspect.

[0046] As can be seen from the above technical solutions, the embodiments of this application have the following advantages:

[0047] This application provides a method for analyzing the cascade utilization of waste heat in a converter station's integrated cooling, heating, and power system. The method includes: determining the structure of the integrated energy system within the converter station's integrated cooling, heating, and power system, and constructing the morphological structure of the integrated energy system; analyzing the cascade recovery modes of waste heat in cooling and heating modes based on the morphological structure, determining a mixed-effect waste heat recovery mode, where the difference between the real-time load demand and the current waste heat output is used as the mode switching trigger condition; performing waste heat conversion analysis based on the mixed-effect waste heat recovery mode, and calculating the waste heat cascade utilization potential parameters, including the total recovered waste heat; configuring the maximum heat recovery and maximum conversion efficiency as optimization objectives based on the waste heat cascade utilization potential parameters, and performing energy output analysis under different operating conditions based on preset energy output constraints and HVAC rated capacity constraints to obtain energy output characteristics, including cooling output and heating output; and plotting the energy output domain performance critical curve based on the energy output characteristics and analyzing the critical point energy efficiency value.

[0048] The waste heat cascade utilization analysis method for converter station integrated cooling, heating, and power systems provided in this application addresses the shortcomings of existing technologies that lack systematic modeling methods by determining the integrated energy system structure and morphology and establishing a standardized system framework. Then, based on the morphological structure, it analyzes the cascade recovery of waste heat in both cooling and heating modes and determines a mixed-effect recovery mode. This mode switching is triggered by the difference between load and waste heat output, replacing the traditional single-effect or dual-effect cooling modes. This precisely matches the characteristics of waste heat of different grades, solving the problems of mismatch between waste heat grade and cooling mode, and waste heat from hot water. Furthermore, based on the mixed-effect mode, waste heat conversion analysis is conducted and the total recovered waste heat is calculated, achieving deep cascade recovery of waste heat and avoiding the problems of insufficient heat recovery and large exergy losses caused by the series recovery of waste heat from flue gas and cylinder liner water. Finally, energy output characteristics are analyzed using dual-objective optimization combined with constraints, performance critical curves are plotted, and critical point energy efficiency is quantified, clarifying the system's energy output law and balancing system reliability and economy. This provides a direct basis for the planning and optimized operation of the converter station's integrated energy system. Therefore, this application can solve the technical problems of existing technologies having extensive waste heat recovery methods, single refrigeration modes, and lack of systematic modeling, resulting in poor actual effects of existing waste heat cascade utilization and the inability to make targeted adjustments and optimizations. Attached Figure Description

[0049] Figure 1 A flowchart illustrating the waste heat cascade utilization analysis method of the converter station integrated cooling, heating and power system provided in the embodiments of this application;

[0050] Figure 2 A schematic diagram of the waste heat cascade utilization analysis device of the converter station integrated cooling, heating and power system provided in the embodiments of this application;

[0051] Figure 3 Example diagram of the energy conversion potential modeling structure of the converter station combined cooling, heating and power system in heating mode provided in the embodiments of this application;

[0052] Figure 4 The energy output domain efficiency analysis curve of the converter station combined cooling, heating and power system provided in the embodiments of this application;

[0053] Figure 5 The COP performance critical curve of the energy output domain of the waste heat utilization system provided in the embodiments of this application. Detailed Implementation

[0054] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0055] For easier understanding, please refer to Figure 1 An embodiment of the waste heat cascade utilization analysis method for converter station integrated cooling, heating and power systems provided in this application includes:

[0056] Step 101: Determine the structure of the integrated energy system in the converter station's integrated cooling, heating and power system, and construct the morphological structure of the integrated energy system.

[0057] The morphological structure refers to the topological configuration description of the converter station's integrated cooling, heating, and power system. Specifically, it includes: ① equipment type and capacity parameters, such as the rated power of the converter station units, the specifications of the absorption chiller, and the rated capacity of the HVAC system; ② energy conversion paths, namely the serial path of high-temperature flue gas → thermoelectric power generation → waste heat recovery, and the parallel recovery path of cylinder liner water / lubricating oil waste heat; ③ operation control rules, with mode switching conditions triggered by the difference between real-time load demand and waste heat output. These three elements together define a complete description of the system's "what equipment, how it is connected, and how it operates," thus defining it as the morphological structure. Subsequent steps, such as waste heat cascade recovery analysis and energy output constraint construction, use this as their input basis.

[0058] This embodiment demonstrates the cascaded utilization of waste heat from the converter station's integrated cooling, heating, and power (CCHP) system by setting the optimal waste heat utilization scheme as the target value for system operation. Once the optimal scheme is determined, the waste heat recovery device and the CCHP equipment can cooperate to promote cascaded energy utilization, resulting in good economic efficiency and allowing for priority planning. Different areas of the converter station can then transmit waste heat through the energy transmission network according to the optimal scheme.

[0059] Specifically, by analyzing the cooling, heating, and power load characteristics and waste heat resource distribution of the converter station, the morphological structure of the integrated cooling, heating, and power system can be determined, thereby establishing an optimized operation model corresponding to the waste heat cascade utilization analysis. Firstly, analyzing the load characteristics and waste heat resource distribution of the converter station allows for the construction of a more rational integrated cooling, heating, and power system. Secondly, waste heat cascade utilization analysis reveals the system's waste heat utilization potential, and the optimization process identifies the optimal operating strategy under different operating conditions. This means that the system can be adjusted according to different situations to generate optimized solutions, effectively guiding the planning and operation of the converter station's integrated cooling, heating, and power system, thereby improving the energy utilization efficiency and economy of the converter station.

[0060] Determining the structure of the integrated energy system involves defining the typical waste heat utilization system structure of the converter station, including the power levels and structural parameters of the converter station units, waste heat cascade utilization system, dual-source driven mixed-effect absorption refrigeration system, and electrically driven HVAC system. The system can meet the electricity, heating, and cooling needs of the converter station users. In general, the process of constructing the energy system structure and form is to determine three core technology configurations: the dual-source driven mixed-effect absorption refrigeration system refrigeration cycle; the mass-quantity serial recovery path of high-temperature flue gas → thermoelectric power generation, and low-temperature flue gas → hot water production; and the electric-driven HVAC supplementary energy supply rule that switches according to the difference between heating and cooling loads.

[0061] Step 102: Analyze the waste heat cascade recovery mode in cooling and heating modes based on the morphological structure, and determine the mixed-effect waste heat recovery mode. The mixed-effect waste heat recovery mode uses the difference between the real-time load demand and the current waste heat output as the mode switching trigger condition.

[0062] In analyzing different waste heat recovery modes, a dual-source driven mixed-effect absorption refrigeration mode can be determined. This mode allows a single absorption chiller to simultaneously utilize two different forms of waste heat, achieving both single-effect and double-effect absorption refrigeration cycles. The dual-source driven mixed-effect absorption refrigeration mode is characterized by its ability to utilize both flue gas and hot water waste heat for refrigeration, while also considering the different grades of waste heat, enabling tiered utilization of waste heat in refrigeration. Furthermore, when only one type of waste heat exists externally, the system can still operate in single-effect or double-effect mode without affecting the waste heat recovery process. Therefore, the mixed-effect waste heat recovery mode in this embodiment can more quickly adapt to the needs of actual scenarios, meeting the requirements for stability and efficiency in waste heat recovery. Switching between different waste heat recovery modes depends on triggering conditions; in this embodiment, the triggering condition is the difference between the real-time load demand and the current waste heat output.

[0063] Further, step 102 includes:

[0064] Based on the form and structure, a single refrigeration unit is configured with a dual-source drive mixed-effect absorption refrigeration mode, which simultaneously realizes single-effect refrigeration cycle and dual-effect refrigeration cycle.

[0065] Based on the analysis of the waste heat recovery characteristics in the cooling and heating modes of the dual-source driven mixed absorption cooling mode, a high-temperature section power generation recovery mode and a low-temperature section waste water flow recovery mode are generated to obtain the mixed waste heat recovery mode.

[0066] A model of an electrically driven HVAC system is built, and the difference between the real-time load demand and the current waste heat output is calculated as the mode switching trigger condition to trigger mode switching.

[0067] The analysis of the waste heat cascade recovery mode in this embodiment aims to clarify the different types of waste heat, such as flue gas, cylinder liner water, and lubricating oil; to clarify the waste heat conversion path or mode, such as power generation, hot water production, or mixed-effect cooling; and to clarify the system equipment and operating mode, such as independent operation or grid-connected boundary operation mode for cooling / heating. Only after determining the characteristics of waste heat recovery and the relevant system structure can subsequent energy efficiency analysis be conducted, that is, to clarify how waste heat is recovered, the recovery equipment, and the recovery mode.

[0068] Specifically, the waste heat utilization system in this embodiment includes converter station units, a waste heat cascade utilization system, a dual-source driven mixed-effect absorption refrigeration system, and an electrically driven HVAC system, with power levels and structural parameters. This system can meet the electricity, heating, and cooling needs of converter station users. The dual-source driven mixed-effect absorption refrigeration mode is determined, allowing a single absorption chiller to simultaneously utilize two different forms of waste heat, i.e., achieving single-effect and double-effect absorption refrigeration cycles.

[0069] In this embodiment, regarding the recovery of quality, the waste heat from the high-temperature section of the flue gas preferentially enters the thermoelectric generator, converting high-grade thermal energy into electrical energy output. The cooling waste heat discharged from the cold end of the thermoelectric generator, along with the low-temperature flue gas, then enters the water flow heat exchange stage. Regarding the recovery of quantity, the heat obtained from the aforementioned heat exchange stage, together with the waste heat from the cylinder liner water and lubricating oil, and the heat from the hot water recovered through independent parallel channels, are combined to deeply recover the sensible heat of the low-temperature hot water section and the latent heat in the working fluid water, for the production of hot water. The quality and quantity recovery on the flue gas side are strictly sequential; that is, the high-temperature section first generates electricity, cools down, and then recovers hot water. The hot water side and the flue gas side operate in parallel without interference. Temperature stratification achieves path decoupling, organically combining the quality and quantity recovery processes to maximize the value of waste heat; this is the hybrid waste heat recovery mode.

[0070] This embodiment also establishes an electric-driven HVAC system model. The difference between the real-time heat load or cooling load and the current waste heat output of the waste heat recovery system is used as the switching trigger condition for the mixed-effect waste heat recovery mode. Specifically, when the difference is positive and represents heat demand, the heating heat pump mode is activated, and the heat pump COP parameters are used to calculate the supplementary heating capacity; when the difference is positive and represents cooling demand, the electric chiller mode is activated, and the cooling COP parameters are used to calculate the supplementary cooling capacity. Both modes share the upper bound constraints of the HVAC rated installed capacity and power consumption. During switching, only the COP value and output type are replaced, while other boundary conditions remain unchanged.

[0071] Step 103: Perform waste heat conversion analysis based on the mixed-effect waste heat recovery mode, and calculate the waste heat cascade utilization potential parameters, including the total recovered waste heat.

[0072] After determining the mixed-effect waste heat recovery mode, it is necessary to analyze the utilization potential of the waste heat recovery system in order to accurately control the efficiency of waste heat recovery. Therefore, this embodiment needs to calculate the waste heat conversion efficiency under different conditions based on the mixed-effect waste heat recovery mode, which is the relevant parameter of the waste heat cascade utilization potential. Specifically, in terms of quantity, deep recovery of hot water waste heat can be implemented, recovering and utilizing the sensible heat of the low-temperature section of hot water and the latent heat in the working fluid for hot water production. In terms of quality, the waste heat of the high-temperature section of flue gas can be recovered through a thermoelectric generator for power generation. By organically combining the quantitative and qualitative recovery processes through the cascade utilization of flue gas waste heat, the value of waste heat can be maximized, that is, the potential for waste heat gradient utilization can be maximized.

[0073] Further, step 103 includes:

[0074] Based on the mixed-effect waste heat recovery model, heat emission analysis was conducted from multiple waste heat emission factors to obtain the waste heat calculation formula;

[0075] Based on the waste heat calculation formula, the waste heat conversion path under the heating mode is analyzed, and the corresponding waste heat recovery is calculated.

[0076] Analyze the waste heat conversion characteristics under the refrigeration mode, calculate the combined cooling capacity and combined COP, and obtain the parameters of waste heat recovery in refrigeration.

[0077] Based on the parameters of waste heat recovered from heating and waste heat recovered from refrigeration, a quantitative analysis was conducted to determine the potential parameters for the cascade utilization of waste heat.

[0078] It should be noted that the waste heat conversion analysis and the calculation of waste heat cascade utilization potential parameters mainly involve calculating the heat distribution, waste heat, and conversion efficiency of various types of waste heat based on the system waste heat recovery path and related rules determined above; then determining the waste heat recovery parameters in the heating mode and the waste heat recovery parameters in the cooling mode, the latter including the mixed-effect cooling capacity and the mixed-effect COP; thus, all potential parameters, namely the waste heat cascade utilization potential parameters, are obtained.

[0079] In the heat generation process of the heating mode, the heat of the high-temperature section of the flue gas is used as input to calculate the electrical energy conversion and cold end waste heat emission of the thermoelectric generator; the heat of the hot water after complete recovery is calculated using the waste heat of the cylinder liner water and the waste heat of the lubricating oil as input; the total hot water output after the two heat sources are combined is solved, and the heat emission factor of each source is quantified.

[0080] The conversion relationship of hot water energy is to construct the conversion equation of cylinder liner water waste heat and lubricating oil waste heat to hot water heat using the heat emission factor as a parameter, and calculate the heat factor values ​​of each heat source under rated and partial load conditions of the converter station.

[0081] The parameter solution involves taking the heat emission factor and heat factor values ​​as inputs, and substituting them into the waste heat calculation formula according to the cooling mode and heating mode respectively, to solve for the recovered waste heat of the converter station under two different modes and different load rates; thus, the total recovered waste heat is obtained.

[0082] Specifically, waste heat mainly includes cylinder liner water waste heat, flue gas waste heat, and lubricating oil waste heat. The loss portion mainly refers to the energy dissipated into the environment in the form of thermal radiation or other heat losses. The cylinder liner water waste heat factor is the ratio of cylinder liner water waste heat to total heat emissions; the lubricating oil waste heat factor is the ratio of lubricating oil waste heat to total heat emissions; the flue gas waste heat factor is the ratio of flue gas waste heat to total heat emissions; and the heat loss factor is the ratio of heat lost in the form of thermal radiation to total heat emissions.

[0083] cylinder liner residual heat factor Lubricating oil residual heat factor Waste heat factor of flue gas and heat loss factor The following relationship exists between them:

[0084]

[0085] Overall power generation efficiency of converter station The mechanical efficiency of the prime mover is determined by the combined efficiency of the two-stage conversion. Electromagnetic conversion efficiency of generator The product of these two values ​​is the overall power generation efficiency of the converter station, which can be calculated as follows:

[0086]

[0087] The fuel consumption of the converter station can be calculated based on the power generation efficiency and total fuel consumption. :

[0088]

[0089] in, This indicates the power generation efficiency of the converter station. This represents the total fuel consumption. Subtracting electricity generation gives the heat emissions, from which the corresponding portion of waste heat for each waste heat factor can be obtained:

[0090]

[0091] Even after waste heat recovery, the emission temperature of flue gas is generally still higher than the ambient temperature. Therefore, not all the heat from the flue gas is recovered; the waste heat factor is utilized. The definition method, in order to Indicates the flue gas from its initial temperature Drop to temperature The ratio of waste heat from flue gas to total heat emissions at a given temperature range; the initial temperature of the flue gas is... , down to The amount of waste heat that can be recovered is:

[0092]

[0093] This represents the total waste heat of the flue gas. Based on these waste heat calculation formulas, the recovered waste heat under different modes can be analyzed.

[0094] Please see Figure 3 In heating mode, deep recovery of flue gas waste heat and flue gas waste heat temperature difference power generation can be adopted. The heat from the high-temperature flue gas is absorbed by the temperature difference power generation device, with a small portion converted into electricity and the majority discharged through the cold end of the device. The heat from the low-temperature flue gas and the heat discharged through the cold end of the device are recovered by water flow. Therefore, the recovered flue gas waste heat is ultimately converted into electricity and hot water heat.

[0095]

[0096] in, , , These represent the residual heat recovered after the flue gas temperature is reduced by T, the electrical energy converted from the heat after the flue gas temperature is reduced by T, and the heat converted into hot water after the flue gas temperature is reduced by T, respectively.

[0097] Waste heat from the cylinder liner water and lubricating oil is recovered as hot water, and can generally be considered as being fully utilized. Therefore, the heat generated by the hot water is:

[0098]

[0099] in, The heat generated from the conversion of waste heat from cylinder liner water and lubricating oil into hot water.

[0100] So, in heating mode, the combined cooling, heating and power system recovers total heat. Expressed as:

[0101]

[0102] Based on these formulas, the amount of waste heat recovered during heating can be calculated, i.e., the total amount of waste heat recovered during heating.

[0103] In cooling mode, the cooling capacity generated by the combined cooling, heating, and power (CCHP) system depends on the COP of the absorption chiller. For a single-effect CCHP system, the cooling capacity output driven by all waste heat is:

[0104]

[0105] in, This indicates that the combined cooling, heating and power system recovers total heat in heating mode. The cooling capacity generated by a single-effect combined cooling, heating and power system. This is the coefficient of performance (COP) for a single-effect combined cooling, heating, and power (CCHP) system. For a double-effect CCHP system, the cooling capacity output driven by flue gas is:

[0106]

[0107] in, The cooling capacity generated by the dual-effect combined cooling, heating and power system This represents the coefficient of performance (COP) for a dual-effect combined cooling, heating, and power (CCHP) system. For a mixed-effect CCHP system, where flue gas drives a dual-effect absorption cycle and hot water drives a single-effect absorption cycle, the approximate cooling capacity output generated by the two types of waste heat is:

[0108]

[0109] in, This represents the cooling capacity generated by a mixed-effect combined cooling, heating, and power (CCHP) system. Therefore, the approximate COP of a dual-source driven mixed-effect absorption refrigeration system with waste heat cascade utilization can be obtained as:

[0110]

[0111] The above calculations yield the combined cooling capacity and combined COP in cooling mode, which are the parameters for waste heat recovery during cooling. Quantitative analysis based on the obtained parameters for waste heat recovery during heating and cooling allows us to determine the potential parameters for cascaded utilization of waste heat, resulting in waste heat-related data for both heating and cooling modes.

[0112] Step 104: Based on the waste heat cascade utilization potential parameters, configure the maximum heat recovery amount and maximum conversion energy efficiency as optimization objectives. According to the preset energy output constraints and HVAC rated capacity constraints, conduct energy output analysis under different operating conditions to obtain energy output characteristics, including cooling output and heating output.

[0113] This embodiment uses the maximum heat recovery rate. and maximum conversion efficiency To achieve a dual objective, the energy output of the converter station's combined cooling and heating system is optimized. The distinction between stand-alone and grid-connected operation is based on whether the power generation exceeds the user's electrical load. In stand-alone operation, the HVAC equipment is not involved in operation, and the recoverable waste heat is a single-valued function of the actual power generation, establishing a one-dimensional energy output constraint relationship—the preset energy output constraint. In grid-connected operation, excess power drives the HVAC equipment. Using the HVAC rated capacity as the upper bound constraint, a binary energy output mode is established, with power generation and user electrical load as the two independent variables, expanding the energy output domain from one-dimensional to two-dimensional. Energy output analysis can then be performed under different operating conditions, such as cooling and heating. By determining the energy output characteristics, the waste heat recovery mechanism can be further adjusted to maximize the energy efficiency of waste heat recovery, better meeting the needs of actual scenarios.

[0114] In the energy output analysis, the electrically driven HVAC system in this embodiment refers to a typical electrically driven vapor compression refrigeration or heating heat pump system. When the system is heating, it refers to the heating heat pump; when the system is cooling, it refers to the chiller. In practical applications, especially in building combined cooling, heating, and power (CCHP) systems in southern regions, it is an indispensable component and has a significant impact on the energy output characteristics of the entire CCHP system. Therefore, incorporating it into the system framework for analysis will help to more comprehensively explain the actual energy conversion and output characteristics of the CCHP system.

[0115] Further, step 104 includes:

[0116] With the maximum heat recovery and maximum conversion efficiency as optimization objectives, the independent operation scenario and the grid-connected operation scenario are defined according to the relationship between power generation and power load, and a preset energy output constraint is constructed.

[0117] The energy output characteristics under different operating conditions are analyzed and calculated by combining preset energy output constraints and HVAC rated capacity constraints.

[0118] It should be noted that the maximum amount of waste heat recovery can be determined based on the recovered waste heat in the waste heat cascade utilization potential parameters, and the optimization target of the maximum heat energy recovery can be defined accordingly; while the mixed-effect COP and conversion energy efficiency in the waste heat cascade utilization potential parameters can be used as system performance indicators in the energy output analysis process; the waste heat recovered for heating and the waste heat recovered for cooling in the waste heat cascade utilization potential parameters directly participate in the energy output characteristic calculation process.

[0119] Specifically, this embodiment uses the maximum heat recovery rate. and maximum conversion efficiency To achieve the dual objectives of energy output from the converter station's combined cooling and heating system, the energy output characteristics of the system must first be analyzed. Since the waste heat from flue gas and hot water differs depending on the power generation, the rated power generation represents the maximum power generation, and its corresponding waste heat is generally also the maximum. For the rated power generation... For a given system, the upper bound of the waste heat function can be determined based on the rated power generation. The recoverable waste heat is the actual power generation of the system. Single-valued functions:

[0120]

[0121] in, A single-valued function describing the mapping relationship between recoverable waste heat from flue gas and power generation, with the actual power generation of the system as the independent variable. The function value is jointly determined by the waste heat factor of the flue gas and the recovery efficiency of the thermoelectric generator. This represents a single-valued function describing the mapping relationship between recoverable waste heat from hot water and power generation. The function value is determined by both the cylinder liner water waste heat factor and the lubricating oil waste heat factor, with the actual power generation of the system as the independent variable.

[0122] If the waste heat from flue gas and waste heat from hot water are combined, the above two equations can be expressed as:

[0123]

[0124] in, Based on the actual power generation of the system It is a single-valued function of the independent variable, describing the direct mapping relationship between total recoverable waste heat and actual power generation. It is calculated by combining flue gas waste heat and hot water waste heat, and is a description of the resource side.

[0125] Then we can analyze the performance indicators of the absorption chiller. Under the assumption that other thermodynamic parameters remain unchanged, the performance of the absorption chiller is affected by the amount of input heat. Therefore:

[0126]

[0127] in, Represented as the actual power generation of the system This is a single-valued function of the independent variable, reflecting the influence of changes in input waste heat on the operating performance of the absorption chiller. This function describes the change of the coefficient of performance of the absorption chiller with the amount of electricity generated. Its physical logic is as follows: the actual amount of electricity generated determines the input waste heat that drives the chiller. The amount of input heat affects the operating conditions of the chiller under the condition that other thermodynamic parameters remain unchanged, thus making the coefficient of performance an indirect function of the amount of electricity generated. Represented as a function The value taken under the current operating conditions represents the actual operating performance coefficient of the absorption chiller, assuming other thermodynamic parameters are constant. It varies with the input heat and is described in the efficiency layer.

[0128] The system's heat output during heating comes not only from waste heat recovery but also from HVAC equipment; however, HVAC equipment has a rated capacity limitation. Based on its rated power consumption, the electrical energy consumed by the equipment does not exceed its rated power consumption. The heat output of the HVAC equipment equals its COP value multiplied by its power consumption. Therefore, the heat output under heating conditions, i.e., the heating output quantity, is expressed as:

[0129]

[0130] in, This is the performance coefficient for electrically driven HVAC equipment. This represents the rated power consumption (kW) of the electrically driven HVAC equipment. It serves as an upper limit constraint on the electrical power required for the HVAC equipment to operate, ensuring that the HVAC equipment does not exceed its rated capacity.

[0131] Similarly, the cooling output of the system during cooling comes not only from waste heat-driven absorption refrigeration but also from electrically driven HVAC equipment. Therefore, the cooling output under cooling conditions, i.e., the cooling output quantity, is expressed as:

[0132]

[0133] The electricity generated is mainly consumed by HVAC equipment and user electrical loads, with a relatively small portion being self-consumption by the system, but the following relationship must be satisfied:

[0134]

[0135] in, This refers to the actual power generation of the generator set. The electricity output by a combined cooling, heating and power (CCHP) system to users. For the user's electrical load, and Equal. Since the system consumes very little power, it is ignored in the qualitative analysis process of this embodiment in order to highlight the main characteristics.

[0136] Step 105: Based on the energy output characteristics, plot the performance critical curve of the energy output domain and analyze the critical point energy efficiency value.

[0137] Specifically, the energy output characteristics data can be compared based on the energy efficiency of traditional distributed power supply systems. The performance critical curves of the energy output domain under different scenarios can be characterized, the energy efficiency of waste heat utilization under different critical points can be analyzed, and the energy efficiency of waste heat utilization under different critical points can be determined to support the energy optimization planning of the converter station waste heat utilization system.

[0138] Specifically, if the power generation equals the electrical load, then electrically driven cooling or heating equipment will not operate. In this case, the heating or cooling capacity has a univariate functional relationship with the electrical load, with one type of electrical load corresponding to one type of heat or cold. The energy output characteristics under these conditions change with the electrical load as follows: Figure 4 As shown by curve ab, the output domain of cold or heat is a one-dimensional function of power generation, and the cold or heat output produced under a specific power output is fixed. Figure 3 The middle segment 'am' represents the heat output of the converter station at idle or the cooling output of the absorption chiller, while the middle segment 'bn' represents the waste heat output of the converter station at full load or the cooling output of the absorption chiller. If the power generation exceeds the electrical load, meaning some electricity is used to drive the HVAC equipment, the system's heat or cooling output expression will have two independent variables, forming a binary function. In this case, the cooling or heating capacity is simultaneously affected by both power generation and electrical output. Therefore, regardless of changes in electrical output, the heat or cooling output can be adjusted by regulating power generation; however, the adjustment of power generation is limited, and the adjustment limit is only within the rated output of the electrically driven HVAC equipment.

[0139] Furthermore, the energy output domain of a combined cooling, heating, and power (CCHP) system can be extended from one dimension to two dimensions, but not all operation within the entire energy output domain is energy-efficient or economical. For example... Figure 5 As shown, the critical performance curve fgh of the system is qualitatively presented. Point f is located within segment ae, point g within segment ab, and point h may be located within either segment bn or gb, depending on the actual equipment performance. The critical performance curve is calculated based on a comparison with traditional distributed power supply systems, combined with power generation efficiency and waste heat conversion efficiency. The performance critical curve trends are similar under cooling and heating modes. In this embodiment, a traditional distributed power supply system refers to a system that uses grid power to drive HVAC equipment for heating or cooling. If the system's energy output is above the critical curve fgh and below the be line, the combined cooling, heating, and power (CCHP) system is more energy-efficient than a traditional distributed power supply system; if it is below the critical curve fgh, the CCHP system is not energy-efficient. Although curve ab represents the lower limit of system energy output, the actual load point may fall below curve ab. If the system operates in this case, since the minimum energy output is curve ab, the system energy output will exceed the load demand, resulting in waste. Some waste of residual heat does not necessarily mean that the system is not energy-efficient. When the load point falls within the area ghbg, the system is still energy-efficient.

[0140] Overall, this embodiment constructs a cooling, heating, and electrical load matching model based on the characteristics of the converter station's cooling, heating, and electrical loads. This model analyzes the spatiotemporal distribution characteristics of cooling, heating, and electrical loads to determine the coupling relationships and complementary characteristics between loads. For example, during peak electricity load periods, waste heat can be used to generate electricity to supplement the power supply; during periods of lower heat load demand, excess heat can be stored or used for cooling. This approach fully considers the contradictory yet closely related relationship between energy efficiency and economy, thereby improving the comprehensiveness of the converter station's integrated cooling, heating, and electrical system planning.

[0141] Furthermore, this embodiment also incorporates a waste heat cascade utilization model and a cooling, heating, and power load matching model to simulate system operation. This process focuses on system energy balance, considering equipment operating constraints such as equipment efficiency and capacity limitations, as well as energy transmission losses, to simulate the system's operating status under different conditions. This process can quantify the system's energy utilization efficiency, waste heat recovery rate, and the degree to which cooling, heating, and power loads are met, thus achieving the sustainable development of the converter station.

[0142] Understandably, in the specific implementation process, traditional energy and waste heat resources can be developed in a coordinated manner according to local conditions, and their complementary use can be promoted. The layout and construction of integrated energy supply infrastructure can be optimized. Through waste heat recovery, combined cooling, heating and power supply and smart energy microgrids, the multi-energy coordinated supply of converter stations and the comprehensive cascade utilization of energy can be promoted.

[0143] The waste heat cascade utilization analysis method for converter station integrated cooling, heating, and power systems provided in this application addresses the shortcomings of existing technologies that lack systematic modeling methods by determining the integrated energy system structure and morphological structure and establishing a standardized system framework. Then, based on the morphological structure, it analyzes the cascade recovery of waste heat in both cooling and heating modes and determines a mixed-effect recovery mode. The mode switching is triggered by the difference between load and waste heat output, replacing the traditional single-effect or dual-effect cooling mode. This accurately matches the characteristics of waste heat of different grades, solving the problems of mismatch between waste heat grade and cooling mode, and waste heat from hot water. Furthermore, based on the mixed-effect mode, waste heat conversion analysis is conducted and the total recovered waste heat is calculated, achieving deep cascade recovery of waste heat and avoiding the problems of insufficient heat recovery and large exergy losses caused by the series recovery of waste heat from flue gas and cylinder liner water. Finally, the energy output characteristics are analyzed using dual-objective optimization combined with constraint conditions, performance critical curves are plotted, and critical point energy efficiency is quantified, clarifying the system's energy output law and balancing system reliability and economy. This provides a direct basis for the planning and optimized operation of the converter station's integrated energy system. Therefore, the embodiments of this application can solve the technical problems of the existing technology having the defects of extensive waste heat recovery methods, single cooling mode and lack of systematic modeling, resulting in poor actual effect of existing waste heat cascade utilization and inability to make targeted adjustments and optimizations.

[0144] For easier understanding, please refer to Figure 2 This application provides an embodiment of an analysis method for the cascade utilization of waste heat in a converter station integrated cooling, heating, and power system, including:

[0145] Morphological structure construction unit 201 is used to determine the structure of the integrated energy system in the converter station's integrated cooling, heating and power system, and to construct the morphological structure of the integrated energy system;

[0146] The waste heat recovery analysis unit 202 is used to analyze the waste heat cascade recovery mode in cooling mode and heating mode based on the morphological structure, and determine the mixed-effect waste heat recovery mode. The mixed-effect waste heat recovery mode uses the difference between the real-time load demand and the current waste heat output as the mode switching trigger condition.

[0147] The potential calculation unit 203 is used to perform waste heat conversion analysis based on the mixed-effect waste heat recovery mode and calculate the waste heat cascade utilization potential parameters, including the total recovered waste heat.

[0148] The energy output analysis unit 204 is used to configure the maximum heat recovery amount and the maximum conversion energy efficiency as optimization targets based on the waste heat cascade utilization potential parameters. It performs energy output analysis under different operating conditions according to preset energy output constraints and HVAC rated capacity constraints to obtain energy output characteristics, including cooling output and heating output.

[0149] The output energy efficiency analysis unit 205 is used to plot the energy output domain performance critical curve based on the energy output characteristics and analyze the critical point energy efficiency value.

[0150] Furthermore, the waste heat recovery analysis unit 202 includes:

[0151] Based on the form and structure, a single refrigeration unit is configured with a dual-source drive mixed-effect absorption refrigeration mode, which simultaneously realizes single-effect refrigeration cycle and dual-effect refrigeration cycle.

[0152] Based on the analysis of the waste heat recovery characteristics in the cooling and heating modes of the dual-source driven mixed absorption cooling mode, a high-temperature section power generation recovery mode and a low-temperature section waste water flow recovery mode are generated to obtain the mixed waste heat recovery mode.

[0153] A model of an electrically driven HVAC system is built, and the difference between the real-time load demand and the current waste heat output is calculated as the mode switching trigger condition to trigger mode switching.

[0154] Furthermore, the potential calculation unit 203 includes:

[0155] Based on the mixed-effect waste heat recovery model, heat emission analysis was conducted from multiple waste heat emission factors to obtain the waste heat calculation formula;

[0156] Based on the waste heat calculation formula, the waste heat conversion path under the heating mode is analyzed, and the corresponding waste heat recovery is calculated.

[0157] Analyze the waste heat conversion characteristics under the refrigeration mode, calculate the combined cooling capacity and combined COP, and obtain the parameters of waste heat recovery in refrigeration.

[0158] Based on the parameters of waste heat recovered from heating and waste heat recovered from refrigeration, a quantitative analysis was conducted to determine the potential parameters for the cascade utilization of waste heat.

[0159] Furthermore, the energy output analysis unit 204 includes:

[0160] With the maximum heat recovery and maximum conversion efficiency as optimization objectives, the independent operation scenario and the grid-connected operation scenario are defined according to the relationship between power generation and power load, and a preset energy output constraint is constructed.

[0161] The energy output characteristics under different operating conditions are analyzed and calculated by combining preset energy output constraints and HVAC rated capacity constraints.

[0162] This application also provides a waste heat cascade utilization analysis device for a converter station integrated cooling, heating and power system, the device including a processor and a memory;

[0163] The memory is used to store program code and transfer the program code to the processor;

[0164] The processor is used to execute the waste heat cascade utilization analysis method of the converter station integrated cooling, heating and power system in the above method embodiment according to the instructions in the program code.

[0165] This application also provides a computer-readable storage medium for storing program code for executing the waste heat cascade utilization analysis method of the converter station integrated cooling, heating and power system in the above method embodiments.

[0166] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0167] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0168] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0169] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for executing all or part of the steps of the methods described in the various embodiments of this application through a computer device (which may be a personal computer, server, or network device, etc.). The aforementioned storage medium includes: USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, optical disks, and other media capable of storing program code.

[0170] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A method for analyzing the cascade utilization of waste heat of a cold heat and power integrated system of a converter station, characterized in that, include: The structure of the integrated energy system in the converter station's integrated cooling, heating, and power system is determined, and the morphological structure of the integrated energy system is constructed. Based on the aforementioned morphological structure, the waste heat cascade recovery mode in cooling and heating modes is analyzed to determine the mixed-effect waste heat recovery mode. The mixed-effect waste heat recovery mode uses the difference between the real-time load demand and the current waste heat output as the mode switching trigger condition. Waste heat conversion analysis is performed based on the aforementioned mixed-effect waste heat recovery mode, and the potential parameters for the cascade utilization of waste heat are calculated. The potential parameters for the cascade utilization of waste heat include the total recovered waste heat. Based on the waste heat cascade utilization potential parameters, the maximum heat recovery amount and the maximum conversion energy efficiency are configured as optimization objectives. Energy output analysis is performed under different operating conditions according to preset energy output constraints and HVAC rated capacity constraints to obtain energy output characteristics, which include cooling output and heating output. Based on the energy output characteristics, a critical performance curve for the energy output domain is plotted, and the critical point energy efficiency value is analyzed.

2. The waste heat cascade utilization analysis method of the converter station integrated cooling, heating and power system according to claim 1, characterized in that, The analysis of the waste heat recovery mode in cooling and heating modes based on the morphological structure determines the mixed-effect waste heat recovery mode. This mixed-effect waste heat recovery mode uses the difference between the real-time load demand and the current waste heat output as the mode switching trigger condition, including: Based on the aforementioned morphological structure, a single refrigeration unit is configured with a dual-source driven mixed-effect absorption refrigeration mode, which simultaneously realizes a single-effect refrigeration cycle and a dual-effect refrigeration cycle. Based on the analysis of the waste heat recovery characteristics in the cooling and heating modes of the dual-source driven mixed absorption cooling mode, a high-temperature section power generation recovery mode and a low-temperature section waste water flow recovery mode are generated to obtain the mixed waste heat recovery mode. A model of an electrically driven HVAC system is built, and the difference between the real-time load demand and the current waste heat output is calculated as the mode switching trigger condition to trigger mode switching.

3. The waste heat cascade utilization analysis method of the converter station integrated cooling, heating and power system according to claim 1, characterized in that, The waste heat conversion analysis is performed based on the hybrid waste heat recovery mode, and the potential parameters for cascade utilization of waste heat are calculated. These potential parameters include the total recovered waste heat, comprising: Based on the aforementioned mixed-effect waste heat recovery mode, heat emission analysis is performed from multiple waste heat emission factors to obtain a waste heat calculation formula; Based on the aforementioned waste heat calculation formula, the waste heat conversion path under the heating mode is analyzed, and the corresponding waste heat recovery is calculated. Analyze the waste heat conversion characteristics under the refrigeration mode, calculate the combined cooling capacity and combined COP, and obtain the parameters of waste heat recovery in refrigeration. Based on the parameters of the waste heat recovered from heating and the waste heat recovered from cooling, a quantitative analysis is performed to determine the potential parameters for the cascade utilization of waste heat.

4. The waste heat cascade utilization analysis method of the converter station integrated cooling, heating and power system according to claim 1, characterized in that, The optimization objectives are set based on the waste heat cascade utilization potential parameters, including the maximum heat recovery and maximum conversion efficiency. Energy output analysis is performed under different operating conditions according to preset energy output constraints and HVAC rated capacity constraints to obtain energy output characteristics, including: With the maximum heat recovery and maximum conversion efficiency as optimization objectives, the independent operation scenario and the grid-connected operation scenario are defined according to the relationship between power generation and power load, and a preset energy output constraint is constructed. The energy output characteristics under different operating conditions are analyzed and calculated by combining the preset energy output constraints and HVAC rated capacity constraints.

5. A waste heat cascade utilization analysis device for a converter station integrated cooling, heating, and power system, characterized in that, include: A morphological structure construction unit is used to determine the structure of the integrated energy system in the converter station's integrated cooling, heating and power system, and to construct the morphological structure of the integrated energy system. The waste heat recovery analysis unit is used to analyze the waste heat cascade recovery mode in cooling mode and heating mode based on the morphological structure, and determine the mixed-effect waste heat recovery mode. The mixed-effect waste heat recovery mode uses the difference between the real-time load demand and the current waste heat output as the mode switching trigger condition. The potential calculation unit is used to perform waste heat conversion analysis based on the mixed-effect waste heat recovery mode and calculate the waste heat cascade utilization potential parameters, which include the total recovered waste heat. The energy output analysis unit is used to configure the maximum heat recovery amount and the maximum conversion energy efficiency as optimization targets based on the waste heat cascade utilization potential parameters, and to perform energy output analysis under different operating conditions according to preset energy output constraints and HVAC rated capacity constraints to obtain energy output characteristics, including cooling output and heating output. The output energy efficiency analysis unit is used to plot the energy output domain performance critical curve based on the energy output characteristics and analyze the critical point energy efficiency value.

6. The waste heat cascade utilization analysis device for the converter station integrated cooling, heating and power system according to claim 5, characterized in that, The waste heat recovery analysis unit includes: Based on the aforementioned morphological structure, a single refrigeration unit is configured with a dual-source driven mixed-effect absorption refrigeration mode, which simultaneously realizes a single-effect refrigeration cycle and a dual-effect refrigeration cycle. Based on the analysis of the waste heat recovery characteristics in the cooling and heating modes of the dual-source driven mixed absorption cooling mode, a high-temperature section power generation recovery mode and a low-temperature section waste water flow recovery mode are generated to obtain the mixed waste heat recovery mode. A model of an electrically driven HVAC system is built, and the difference between the real-time load demand and the current waste heat output is calculated as the mode switching trigger condition to trigger mode switching.

7. The waste heat cascade utilization analysis device for the converter station integrated cooling, heating and power system according to claim 5, characterized in that, The utilization potential calculation unit includes: Based on the aforementioned mixed-effect waste heat recovery mode, heat emission analysis is performed from multiple waste heat emission factors to obtain a waste heat calculation formula; Based on the aforementioned waste heat calculation formula, the waste heat conversion path under the heating mode is analyzed, and the corresponding waste heat recovery is calculated. Analyze the waste heat conversion characteristics under the refrigeration mode, calculate the combined cooling capacity and combined COP, and obtain the parameters of waste heat recovery in refrigeration. Based on the parameters of the waste heat recovered from heating and the waste heat recovered from cooling, a quantitative analysis is performed to determine the potential parameters for the cascade utilization of waste heat.

8. The waste heat cascade utilization analysis device for the converter station integrated cooling, heating and power system according to claim 5, characterized in that, The energy output analysis unit includes: With the maximum heat recovery and maximum conversion efficiency as optimization objectives, the independent operation scenario and the grid-connected operation scenario are defined according to the relationship between power generation and power load, and a preset energy output constraint is constructed. The energy output characteristics under different operating conditions are analyzed and calculated by combining the preset energy output constraints and HVAC rated capacity constraints.

9. A waste heat cascade utilization analysis device for a converter station integrated cooling, heating, and power system, characterized in that, The device includes a processor and a memory; The memory is used to store program code and transmit the program code to the processor; The processor is used to execute the waste heat cascade utilization analysis method of the converter station integrated cooling, heating and power system according to any one of the claims 1-4, based on the instructions in the program code.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium is used to store program code for executing the waste heat cascade utilization analysis method of the converter station integrated cooling, heating and power system according to any one of claims 1-4.

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