Combined heat and power supply system, combined heat and power supply control method and device and computer equipment

Abstract

The invention relates to a combined heat and power supply system, a combined heat and power supply control method and device and computer equipment, the system comprises a fuel cell power generation subsystem and a waste heat boiler which are connected, and a steam power generation heat supply subsystem and a heat storage subsystem which are connected with the waste heat boiler, the waste heat boiler heats water through smoke and inputs generated steam into a steam turbine of the steam power generation and heat supply subsystem, the steam turbine uses part of the steam for driving a power generator to supply power and pumps part of the steam into a heat supply network heater to supply heat, and the waste heat boiler further heats a heat storage medium conveyed by a first heat storage device through the smoke. And the heated heat storage medium is input into the second heat storage device, and the second heat storage device conveys the heated heat storage medium into the supplementary heating network heater for heat supply. By the adoption of the system, the thermal load requirement can be better met.

Description

Technical Field

[0001] This application relates to the field of combined heat and power (CHP) technology, and in particular to a CHP system, CHP control method, device, computer equipment, storage medium, and computer program product. Background Technology

[0002] With the development of industrial technology, various new types of fuels have also gradually developed, such as solid oxide fuel cells, which are high-efficiency energy conversion devices that directly convert the chemical energy of fuel into electrical energy through electrochemical reactions. They have high power generation efficiency and great waste heat utilization value.

[0003] In traditional solutions, solid oxide fuel cells are typically used as the basis for achieving combined heat and power (CHP). These cells utilize fuels such as natural gas, syngas, and hydrogen, and are combined with methods such as steam power cycles, organic Rankine cycles, and absorption refrigeration cycles to utilize the heat released from combustion.

[0004] However, in distributed energy systems, it is necessary to ensure that the supply of heat and electricity is consistent with the demand as much as possible. Considering the working principle of solid oxide fuel cells, when the system electrical load is low, the system's heating capacity is reduced due to the limitations of equipment operating conditions, and there is a risk that the heat load demand cannot be met. Summary of the Invention

[0005] Therefore, it is necessary to provide a combined heat and power system, a combined heat and power control method, an apparatus, a computer device, a computer-readable storage medium, and a computer program product that can meet the system's heat load in order to address the above-mentioned technical problems.

[0006] In a first aspect, this application provides a combined heat and power (CHP) system. The system includes a fuel cell power generation system and a waste heat boiler connected together, as well as a steam power generation and heating subsystem and a thermal storage subsystem connected to the waste heat boiler. The steam power generation and heating subsystem includes a steam turbine connected to the waste heat boiler, and a generator and a heat network heater connected to the steam turbine. The thermal storage subsystem includes a first thermal storage device and a second thermal storage device connected to the waste heat boiler, and a supplementary heat network heater connected to the second thermal storage device. The supplementary heat network heater is connected to the heat network heater of the steam power generation and heating subsystem.

[0007] The fuel cell power generation system generates electricity and produces flue gas based on an electrochemical reaction. The waste heat boiler heats water through the flue gas and inputs the generated steam into the steam turbine of the steam power generation and heating subsystem. The steam turbine uses part of the steam to drive the generator to supply electricity and draws part of the steam into the heating network heater for heating.

[0008] When the heat energy generated by the steam power generation and heating subsystem is greater than or equal to the heat load demand of the system, the waste heat boiler also heats the heat storage medium transported by the first heat storage device through flue gas, and inputs the heated heat storage medium into the second heat storage device.

[0009] When the heat energy generated by the steam power generation and heating subsystem is less than the heat load demand of the system, the heated heat storage medium in the second heat storage device is transported to the supplementary heating network heater for heating.

[0010] Secondly, this application also provides a combined heat and power (CHP) control method. The method includes:

[0011] Obtain the electrical load and thermal load requirements of the system;

[0012] When the electrical load demand is less than the power generation of the system, a preset adaptive algorithm is used to determine the amount of reduction in the steam flow rate entering the steam power generation and heating subsystem, and the steam flow rate entering the steam power generation and heating subsystem is reduced according to the amount of reduction.

[0013] When the power generation of the steam power generation and heating subsystem decreases to a preset electrical load threshold, the input of fuel and air to the fuel cell power generation system is reduced.

[0014] Based on the heat load demand of the system, the amount of steam used for heating in the steam power generation and heating subsystem is adjusted so that the heat output of the steam power generation and heating subsystem meets the heat load demand of the system. If the heat output of the steam power generation and heating subsystem cannot meet the heat load demand of the system, heat is released through the heated heat storage medium in the second heat storage device for heating.

[0015] Thirdly, this application also provides a combined heat and power control device, the device comprising:

[0016] The data acquisition module is used to acquire the electrical load demand and thermal load demand of the system;

[0017] A steam flow regulation module is used to determine the amount of reduction in the steam flow entering the steam power generation and heating subsystem by means of a preset adaptive algorithm when the electrical load demand is less than the power generation of the system, and to reduce the steam flow entering the steam power generation and heating subsystem according to the amount of reduction.

[0018] The battery power generation regulation module is used to reduce the input of fuel and air to the fuel cell power generation system when the power generation of the steam power generation and heating subsystem decreases to a preset electrical load threshold.

[0019] The supplementary heat control module is used to adjust the amount of steam used for heating in the steam power generation and heating subsystem based on the heat load demand of the system, so that the heat output of the steam power generation and heating subsystem meets the heat load demand of the system. If the heat output of the steam power generation and heating subsystem cannot meet the heat load demand of the system, heat is released through the heated heat storage medium in the second heat storage device for heating.

[0020] Fourthly, this application also provides a computer device. The computer device includes a memory and a processor, the memory storing a computer program, and the processor executing the computer program to implement the steps described in the above-described embodiments of the combined heat and power control method.

[0021] Fifthly, this application also provides a computer-readable storage medium. The computer-readable storage medium stores a computer program thereon, which, when executed by a processor, implements the steps in the above-described embodiments of the combined heat and power control method.

[0022] Sixthly, this application also provides a computer program product. The computer program product includes a computer program that, when executed by a processor, implements the steps described in the embodiments of the combined heat and power control method.

[0023] In the aforementioned combined heat and power (CHP) system, the fuel cell power generation system meets electrical load demands based on electrochemical reactions. Simultaneously, the generated flue gas enters a waste heat boiler, allowing the system to effectively utilize the waste heat generated during power generation, providing a foundation for subsequent heating and power generation. Steam generated from heating water in the waste heat boiler enters the steam turbine of the steam power generation and heating subsystem. The steam turbine uses part of the steam to drive the generator for power supply and extracts part of the steam into the heating network heaters for heating. The heat from the steam is used to meet both heat load and electrical load demands, making the system more flexible in meeting different load requirements and alleviating the problem of singular changes in electrical and heat loads. This is especially beneficial when the heat energy generated by the steam power generation and heating subsystem is greater than or equal to the system's heat load demand. The waste heat boiler also heats the heat storage medium delivered by the first heat storage device through flue gas, and inputs the heated heat storage medium into the second heat storage device. In addition, when the heat energy generated by the steam power generation and heating subsystem is less than the system's heat load demand, the heated heat storage medium in the second heat storage device is delivered to the supplementary heating network heater for heating. In this way, when the system has a heat surplus, the excess heat can be stored. Since the waste heat generated by the fuel cell power generation system may decrease, the heated heat storage medium stored in the heat storage subsystem can supplement the heat supply to meet the system's heat load demand. This achieves thermoelectric decoupling of the system, effectively reduces the risk of insufficient heat supply capacity due to low system electrical load, and ensures a stable supply of heat load demand. The aforementioned combined heat and power (CHP) control method, device, computer equipment, storage medium, and computer program products, when the system's electrical load demand is less than the system's power generation, determine the reduction in steam flow entering the steam power generation and heating subsystem through a preset adaptive algorithm. Based on this reduction, the steam flow entering the steam power generation and heating subsystem is reduced, thereby reducing the subsystem's power generation. When the power generation of the steam power generation and heating subsystem decreases to a preset electrical load threshold, the amount of fuel and air entering the fuel cell power generation system is reduced, ensuring that the system's power generation matches the electrical load demand. Furthermore, since a reduction in system power generation often reduces system heat generation to some extent, the amount of steam used for heating in the steam power generation and heating subsystem is adjusted to ensure its heat generation meets the system's heat load demand. If the system's heat load demand is high and the heat generation of the steam power generation and heating subsystem cannot meet the system's heat load demand, the heat stored in the heated heat storage medium in the heat storage subsystem can be utilized. By releasing the stored heat, the system's thermoelectricity can be decoupled, effectively solving the problem of insufficient system heat load supply. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of a combined heat and power system in one embodiment;

[0025] Figure 2This is a schematic diagram of the combined heat and power system in another embodiment;

[0026] Figure 3 This is a flowchart illustrating a combined heat and power (CHP) control method in one embodiment.

[0027] Figure 4 This is a flowchart illustrating the combined heat and power control method in a detailed embodiment;

[0028] Figure 5 This is a structural block diagram of a combined heat and power control device in one embodiment;

[0029] Figure 6 This is a structural block diagram of the combined heat and power control device in another embodiment;

[0030] Figure 7 This is an internal structural diagram of a computer device in one embodiment. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0032] In one embodiment, such as Figure 1 As shown, a combined heat and power (CHP) system 100 is provided. The system 100 includes a fuel cell power generation system 110 and a waste heat boiler 120 connected to each other, as well as a steam power generation and heating subsystem 130 and a thermal storage subsystem 140 connected to the waste heat boiler 120. The steam power generation and heating subsystem 130 includes a steam turbine 131 connected to the waste heat boiler 120, a generator 132 connected to the steam turbine 131, and a heat network heater 133. The thermal storage subsystem 140 includes a first thermal storage device 141 and a second thermal storage device 142 connected to the waste heat boiler 120, and a supplementary heat network heater 143 connected to the second thermal storage device 142. The supplementary heat network heater 143 is connected to the heat network heater 133 of the steam power generation and heating subsystem 130.

[0033] The fuel cell power generation system 110 generates electricity and produces flue gas based on an electrochemical reaction. The waste heat boiler 120 heats water through the flue gas and inputs the generated steam into the steam turbine 131 of the steam power generation and heating subsystem 130. The steam turbine 131 uses part of the steam to drive the generator 132 to generate electricity and draws part of the steam into the heating network heater 133 for heating.

[0034] When the heat energy generated by the steam power generation and heating subsystem 130 is greater than or equal to the heat load demand of the system, the waste heat boiler 120 also heats the heat storage medium delivered by the first heat storage device 141 through flue gas, and inputs the heated heat storage medium into the second heat storage device 142.

[0035] When the heat energy generated by the steam power generation and heating subsystem 130 is less than the heat load demand of the system, the heated heat storage medium in the second heat storage device 142 is transported to the supplementary heat network heater 143 for heating.

[0036] The combined heat and power (CHP) system 100 is an energy system integrating power generation and heating functions. It can generate electricity through electrochemical reactions using fuel chemical energy and recover waste heat for heating, while achieving thermoelectric decoupling through a thermal storage device. In this embodiment, the CHP system 100, through the synergy of the fuel cell power generation system 110, the waste heat boiler 120, the steam power generation and heating subsystem 130, and the thermal storage subsystem 140, can improve the overall energy utilization rate to over 85%, making it suitable for distributed energy scenarios (such as industrial parks and isolated residential areas). The fuel cell power generation system 110 may include a solid oxide fuel cell, which directly generates electricity through the electrochemical reaction of fuel gas (such as natural gas or hydrogen) with air, while simultaneously generating high-temperature flue gas as a waste heat source. The waste heat boiler 120 may be a heat exchange device with a multi-flue structure, used to recover the waste heat from the flue gas discharged by the fuel cell power generation system 110.

[0037] The steam power generation and heating subsystem 130 can directly utilize the heat of steam or use the heat of steam to drive a generator to generate electricity, thereby achieving combined heat and power (CHP). For example, the steam turbine 131 uses steam heat energy to drive the generator 132 to generate electricity. After analysis and verification, when the steam flow rate is 56.2 kg / s, it generates 63 MW of electricity, with a power adjustment range between 42.1 and 63.0 MW. It can also extract a portion of the steam from the steam turbine 131 (such as an extraction ratio of 44.3% to 80%) through the extraction steam flow regulating valve, and heat the heating network water through the heating network heater 133 to achieve heating.

[0038] The thermal energy storage subsystem 140 consists of a thermal energy storage medium circulation loop and heat exchange equipment, enabling the storage and release of thermal energy. The first thermal energy storage device 141 stores cold thermal energy storage medium (such as 200℃ binary molten salt), and the second thermal energy storage device 142 stores hot thermal energy storage medium (i.e., heated thermal energy storage medium, such as 500℃ binary molten salt). The supplementary heating network heater 143 is used to supplement heat supply when there is insufficient heating by exchanging heat between the hot thermal energy storage medium and the heating network water. The designed heat exchange capacity is up to 114.5MW (calculated under the condition that the temperature difference between the cold and hot thermal energy storage media is 300℃ and 75.5kg of thermal energy storage medium is exchanged per second). It is understood that the preferred thermal energy storage medium is binary molten salt, with an operating temperature of 200-500℃, a specific heat capacity of 1.5kJ / kg・K, a thermal energy storage density of 450MJ / m³, high-temperature stability, and a low freezing point (approximately 142℃), making it suitable for large-scale sensible heat storage.

[0039] For example, the workflow in the fuel cell power generation system 110 can be as follows: fuel gas (such as a natural gas mixture with a flow rate of 5.5 kg / s) and air (flow rate of 321.4 kg / s) of the fuel cell power generation system 110 undergo an electrochemical reaction in the solid oxide fuel cell to generate 120 MW of electrical energy. Simultaneously, the anode exhaust (containing unreacted fuel) mixes with the cathode exhaust and enters the combustion chamber for combustion, generating high-temperature flue gas at 326.9 kg / s and 833.9°C. The flue gas enters the waste heat boiler 120 and exchanges heat countercurrently with the water tube bundle, heating the feedwater (temperature of 31°C and flow rate of 56.2 kg / s) into superheated steam at 500°C and 15 MPa, which is then input into the inlet of the steam turbine 131. Steam turbine 131 converts part of the steam energy (approximately 55.7%-90%) into mechanical energy, which is then used for power generation. The remaining steam is drawn into the heating network heater 133 via a steam extraction flow regulating valve (steam extraction ratio 44.3%-10%), which heats the heating network water at a flow rate of 800t / h from 70℃ to 130℃.

[0040] For example, the working process of the steam power generation and heating subsystem 130 can be as follows: When the system's electrical load decreases (e.g., from 183MW to 162.1MW), the steam flow rate of the steam turbine 131 is preferentially reduced via the steam flow regulating valve 61 (e.g., from 56.2kg / s to 50.6kg / s), and the power of the generator 132 decreases accordingly (63MW→42.1MW), while the fuel cell power generation system 110 maintains full-load operation (120MW). When the system's heat load increases (e.g., the flow rate demand of the heating network water increases from 600t / h to 800t / h), the extraction steam ratio can be increased via the extraction steam flow regulating valve (e.g., from 44.3% to 49.2%), and the power generation of the steam turbine 131 decreases due to the reduced steam flow rate (63MW→48.4MW), but the heat exchange capacity of the heating network heater 133 increases (e.g., from 420GJ / h to 560GJ / h) to meet the system's heat load demand.

[0041] For example, the heat storage process of the thermal storage subsystem 140 can be: when the heating capacity of the steam power generation and heating subsystem 130 is greater than the heat load demand, and the load of the fuel cell power generation and heating system 110 is ≥80% of the rated power (when the electrical load is high and the heat load is low), then the heat storage is started. Taking binary molten salt (hereinafter referred to as molten salt) as the heat storage medium as an example, the cold molten salt (200℃, 49.0kg / s) in the first heat storage device 141 is sent to the waste heat boiler 120 for countercurrent heat exchange with 10% of the flue gas (32.69kg / s, 833.9℃). After absorbing the waste heat from the flue gas, the cold molten salt heats up to 500℃, forming hot molten salt, which then flows through a pipeline into the second heat storage device 142 (e.g., with a volume of 3000m³) for storage. The single heat storage time is 6.8 hours, and the total stored heat is 497.36GJ (calculation formula: 49kg / s×1.5kJ / kg・K×300K×6.8×3600s). It is understandable that the flow rate of the cold molten salt requiring heat exchange can be determined using an adaptive algorithm. Taking the heat storage medium exchanging heat with the flue gas through the second flue of the waste heat boiler 120 as an example, the flow rate of the heat storage medium during the heat storage process... It should satisfy equation (1):

[0042] (1)

[0043] In equation (1), This refers to the mass flow rate of the heat storage medium during the heat storage process. The flue gas velocity in the second flue of the waste heat boiler; This refers to the cross-sectional area of ​​the second flue of the waste heat boiler. The specific volumetric heat capacity of the flue gas is ; The specific heat capacity of the heat storage medium during the heat storage process; The inlet flue gas temperature of the second flue of the waste heat boiler; The temperature of the flue gas at the outlet of the second flue of the waste heat boiler; The temperature of the high-temperature thermal storage medium in the second thermal storage device; The temperature of the high-temperature thermal storage medium in the first thermal storage device; This refers to the heat exchange efficiency between the flue gas and the heat storage medium in the second flue of the waste heat boiler. These are the design parameters for the waste heat boiler. , , , , For directly measured parameters; , , These parameters are related to the working fluid temperature, pressure, composition, etc., and this relationship is determined based on the system commissioning situation.

[0044] For example, the heat release process of the thermal storage subsystem 140 can be as follows: when the heating capacity of the steam power generation and heating subsystem 130 is insufficient (e.g., the outlet temperature of the heating network water at the heating network heater 133 is lower than the target temperature value), the steam extraction flow rate has reached its maximum value (e.g., the steam extraction ratio is greater than or equal to 80%, indicating that the steam power generation and heating subsystem 130 has reached its heating limit), the liquid level of the second thermal storage device 142 is greater than or equal to 10% (ensuring sufficient hot molten salt, the specific value can be modified according to the actual situation), and the liquid level of the first thermal storage device 141 is less than or equal to 90% (ensuring sufficient space to accommodate the cold molten salt after heat release, the specific value can be modified according to the actual situation), the hot molten salt in the second thermal storage device 142 is transported to the supplementary heating network heater 143 for countercurrent heat exchange with the heating network water. The heating network water absorbs the heat released by the molten salt, and its temperature rises to meet the heating demand. After the hot molten salt releases heat, its temperature decreases to form cold molten salt, which is returned to the first thermal storage device 141 for recycling through the pipeline. Understandably, the flow rate of the hot molten salt requiring heat exchange and the flow rate of the heat storage medium during heat release can be determined using an adaptive algorithm. Satisfying equation (2):

[0045] (2)

[0046] In equation (2), where: This refers to the mass flow rate of the heat storage medium during the heat release process. Specific heat capacity of the heating network water; The specific heat capacity of the heat storage medium during the heat release process; This refers to the flow rate of the heating network. To supplement the heating network heater's heating network water inlet temperature; To supplement the inlet and outlet temperatures of the heating network heaters; The temperature of the high-temperature heat storage medium in the second heat storage device 142; The temperature of the high-temperature heat storage medium in the first heat storage device 141; To improve the heat exchange efficiency between the heating network water and the heat storage medium in the heating network heater 143.

[0047] In this embodiment, the aforementioned combined heat and power (CHP) system utilizes a fuel cell power generation system to meet electrical load demands based on an electrochemical reaction. Simultaneously, the generated flue gas enters a waste heat boiler, enabling the system to effectively utilize the waste heat generated during power generation, providing a foundation for subsequent heating and power generation. Steam generated from heating water in the waste heat boiler enters the steam turbine of the steam power generation and heating subsystem. The steam turbine uses part of the steam to drive the generator for power supply and extracts part of the steam into the heating network heater for heating. The heat from the steam is used to meet both heat load and electrical load demands, making the system more flexible in meeting different load requirements and alleviating the problem of singular changes in electrical and heat loads. This is especially beneficial when the heat energy generated by the steam power generation and heating subsystem is greater than or equal to the system's heat load demand. In this case, the waste heat boiler also heats the heat storage medium transported by the first heat storage device through flue gas, and inputs the heated heat storage medium into the second heat storage device. In addition, when the heat energy generated by the steam power generation and heating subsystem is less than the system's heat load demand, the heated heat storage medium in the second heat storage device is transported to the supplementary heating network heater for heating. In this way, when the system has a heat supply surplus, the excess heat can be stored. Since the waste heat generated by the fuel cell power generation system may decrease, the heated heat storage medium stored in the heat storage subsystem can supplement the heat supply to meet the system's heat load demand. This achieves thermoelectric decoupling of the system, effectively reduces the risk of insufficient heat supply capacity due to low system electrical load, and achieves a stable supply of heat load demand.

[0048] In one embodiment, such as Figure 2 As shown, the steam power generation and heating subsystem 130 also includes a feedwater pump 134 connected to the waste heat boiler 120, a condenser 135 connected to the steam turbine 131, a steam flow regulating valve 136 installed on the connecting pipe between the waste heat boiler 120 and the steam turbine 131, and an extraction steam flow regulating valve 137 installed on the connecting pipe between the steam turbine 131 and the heat network heater 133. The feedwater pump 134 is connected to the condenser 135. The condenser 135 condenses the residual steam in the steam turbine 131 into water, and the feedwater pump pumps the water formed by the condensation of the residual steam into the waste heat boiler 120. The steam flow regulating valve 136 is used to regulate the amount of steam entering the steam turbine 131. The extraction steam flow regulating valve 137 is used to regulate the amount of steam extracted into the heat network heater 133.

[0049] The feedwater pump 134 is used to pressurize and transport the water condensed by the condenser 135 to the waste heat boiler 120. It can be a centrifugal pump, and its head needs to match the working pressure of the waste heat boiler 120. The flow rate of the feedwater pump 134 is related to the steam inlet flow rate of the steam turbine 131. For example, when the steam inlet flow rate of the steam turbine 131 is 56.2 kg / s, the flow rate of the feedwater pump 134 is 56.2 kg / s. The condenser 135 is a heat exchange device used to condense the low-pressure steam discharged from the steam turbine 131 into liquid water. It can adopt a shell-and-tube structure, using circulating cooling water or air as the cooling medium. In this embodiment, the pressure of the condenser 135 under vacuum can be designed to be less than or equal to 0.01 MPa, and the heat exchange efficiency greater than or equal to 95%, thereby achieving a low-pressure steam condensation rate greater than 99% to reduce working fluid loss. A steam flow regulating valve 136 is installed on the pipeline between the waste heat boiler 120 and the steam turbine 131 to regulate the steam flow rate entering the steam turbine 131. In this embodiment, the steam flow regulating valve 136 can be a pneumatic or electric regulating valve with a response time of less than or equal to 3 seconds, a regulation accuracy of ±1%, and the ability to withstand a high temperature of 500℃ and a high pressure of 15MPa. An extraction steam flow regulating valve 137 is installed on the pipeline between the extraction port of the steam turbine 131 and the heat network heater 133 to control the amount of steam extracted for heating. In this embodiment, the extraction steam flow regulating valve 137 can be designed to be suitable for two-phase steam flow conditions, with an regulation range of 0-80% of the rated flow and a leakage rate of less than 0.5%.

[0050] Specifically, during the steam power generation stage, the high-temperature, high-pressure steam generated by the waste heat boiler 120 is regulated by the steam flow regulating valve 136 and then enters the steam turbine 131 to expand and perform work, driving the generator 132 to generate electricity. During the steam condensation stage, the low-temperature, low-pressure steam discharged from the steam turbine 131 enters the condenser 135, exchanges heat with the cooling medium (such as circulating water), and condenses into water. The condensate can be stored in the water collection tank at the bottom of the condenser 135. During the working fluid recovery stage, the feedwater pump 134 pressurizes the condensate in the water collection tank at the bottom of the condenser 135 to match the working pressure of the waste heat boiler (e.g., 15 MPa), and then transports it to the waste heat boiler 120 via pipeline, completing the steam-water cycle. For example, when the system's electrical load is relatively high, the system operates at full load. At this time, the opening of the steam flow regulating valve 136 can be 100%, the steam flow into the steam turbine 131 reaches the rated value of 56.2 kg / s, and the generator 132 outputs 63 MW. In this case, the steam power generation and heating subsystem 130 is mainly used for power generation. Understandably, while generator 132 is generating electricity, a power sensor can be used to monitor the actual power output of generator 132 and calculate the difference with a given target power value (e.g., 63MW). If the difference is greater than 5%, a PID (Proportional-Integral-Derivative Control Algorithm) algorithm can be used to adjust the opening of steam flow regulating valve 136 and synchronously adjust the speed of feedwater pump 134 (e.g., adjust the frequency converter of feedwater pump 134) to match the feedwater flow with the steam flow and maintain a stable water level in waste heat boiler 120. The waste flue gas in waste heat boiler 120 can be discharged directly through the flue gas outlet, or it can be treated by a specific treatment device (not shown in the figure) before being discharged.

[0051] Furthermore, the extraction steam flow regulating valve 137 is used to regulate the amount of steam extracted into the heating network heater 133. Therefore, a temperature sensor can also be set to monitor the outlet water temperature of the heating network heater 133. The difference between the outlet water temperature and the given temperature value is calculated. If the difference is too large, the opening of the extraction steam flow regulating valve 136 can be adjusted through a PID algorithm until the water temperature reaches the standard. At the same time, the flow rate of the steam turbine 131 (inlet steam flow rate - extraction steam flow rate) is monitored. If the flow rate is close to the design minimum value (e.g., 10 kg / s), the increase in extraction steam is automatically limited (e.g., the opening of the extraction steam flow regulating valve 137 is limited to less than or equal to 80%). At this time, the heating supply of the steam power generation and heating subsystem 130 has reached its limit, and the thermal storage subsystem 140 needs to be triggered for supplemental heating.

[0052] In this embodiment, the condenser condenses the residual steam that has not fully performed work in the steam turbine into liquid water, which is then reinjected into the waste heat boiler via a feedwater pump. This allows the waste heat from the fuel cell to be fully utilized for power generation and heating, achieving the recycling of the working fluid. The linkage between the steam flow regulating valve and the extraction steam flow regulating valve can regulate the power generation and heating output of the steam power generation and heating subsystem, achieving thermoelectric decoupling control, improving the flexibility of system regulation, and better meeting the system's electrical and thermal load requirements.

[0053] In one embodiment, such as Figure 2 As shown, a first working fluid pump 144 and a first check valve 145 are provided between the waste heat boiler 120 and the first heat storage device 141. The first working fluid pump 144 is used to pump the heat storage medium in the first heat storage device 141 into the waste heat boiler 120 for heating. A second working fluid pump 146 and a second check valve 147 are provided between the second heat storage device 142 and the supplementary heat network heater 143. The second working fluid pump 146 is used to pump the heated heat storage medium in the second heat storage device 142 into the supplementary heat network heater 143.

[0054] The first working fluid pump 144 drives the cold thermal storage medium in the first thermal storage device 141 into the waste heat boiler 120. In this embodiment, the first working fluid pump 144 can be a high-temperature molten salt pump. A first check valve 145 is installed on the pipeline between the first working fluid pump 144 and the waste heat boiler 120 to prevent the thermal storage medium from flowing back into the first thermal storage device 141 when the pump stops. In this embodiment, the first check valve 145 can be a swing valve and made of a high-temperature and high-pressure resistant material. The second working fluid pump 146 transports the hot thermal storage medium in the second thermal storage device 142 to the supplementary heating network heater 143. In this embodiment, the second working fluid pump 146 and the first working fluid pump 144 can have the same structure and parameters, and possess the same high-temperature and high-pressure resistance. A second check valve 147 is installed on the pipeline between the second working fluid pump 146 and the supplementary heating network heater 143 to prevent the thermal storage medium from flowing back into the second thermal storage device 142 when the pump stops. In this embodiment, the second check valve 147 can have the same structure and parameters as the first check valve 145, so that the high-temperature molten salt flows in one direction, reducing the safety risks caused by contact with the heating network water.

[0055] For example, when the system meets the heat storage conditions, the first working fluid pump 144 will operate at its rated speed, pumping the cold heat storage medium in the first heat storage device 141 into the waste heat boiler 120. By adjusting the speed of the first working fluid pump 144, the flow rate of the cold heat storage medium entering the waste heat boiler 120 can be adjusted, thereby enabling the cold heat storage medium in the waste heat boiler 120 to store excess heat. When the first working fluid pump 144 stops or malfunctions, the first check valve 145 will automatically close to prevent high-temperature flue gas from flowing back into the first heat storage device 141. Finally, the hot heat storage medium formed by heating in the waste heat boiler 120 enters the second heat storage device 142 for storage.

[0056] When the supplementary heating network heater 143 requires supplemental heating, the second working fluid pump 146 starts, pumping the hot heat storage medium from the second heat storage device 142 into the supplementary heating network heater 143 at its rated speed. It can be understood that the flow rate of the hot heat storage medium can be adjusted by changing the speed of the second working fluid pump 146 until the heating network water temperature reaches the standard. When the second working fluid pump 146 stops or the pressure on the heating network water side rises abnormally, the second check valve 147 will automatically close to prevent backflow of heating network water into the heat storage circuit and to prevent boiling over from the water contacting the high-temperature molten salt.

[0057] It should be noted that the operating state of the first working fluid pump 144 is related to the liquid level of the first heat storage device 141 (to prevent the pump from running dry), the flue gas volume of the waste heat boiler 120 (to ensure sufficient flue gas for heating), and the liquid level of the second heat storage device 142 (to prevent the hot heat storage medium from overflowing). The operating state of the second working fluid pump 146 is related to the liquid level of the second heat storage device 142 (to prevent the pump from running dry), the inlet and outlet pressure difference of the supplementary heating network heater 143 (to prevent the heat exchange tube from being blocked), and the liquid level of the first heat storage device 141 (to ensure sufficient space to receive the cold heat storage medium).

[0058] In this embodiment, through the bidirectional regulation mechanism of heat storage and heat release in the heat storage subsystem, when the system heat load is low, the first working fluid pump drives the heat storage medium to flow through the waste heat boiler to absorb the waste heat of the fuel cell flue gas. When the system heat load is high, the second working fluid pump pumps the hot heat storage medium in the second heat storage device into the supplementary heat network heater to quickly make up for the heat supply gap, decouple the rigid correlation between fuel cell heating and real-time heat load, and well meet the dynamic requirements of system heat load.

[0059] In one embodiment, such as Figure 2As shown, the thermal storage subsystem 140 also includes a first regulating valve 148 disposed between the first working fluid pump 144 and the waste heat boiler 120, and a second regulating valve 149 disposed between the second working fluid pump 146 and the supplementary heating network heater 143; the first regulating valve 148 is used to regulate the amount of thermal storage medium pumped into the waste heat boiler 120, and the second regulating valve 149 is used to regulate the amount of heated thermal storage medium pumped into the supplementary heating network heater 143.

[0060] The first regulating valve 148 is installed on the pipeline between the first working fluid pump 144 and the waste heat boiler 120, and is used to precisely regulate the flow rate of the heat storage medium entering the waste heat boiler 120. In this embodiment, the first regulating valve 148 can be an electric regulating ball valve with a flow capacity Cv value of 50 (corresponding to a maximum flow rate of 50 kg / s), a regulation ratio of 100:1, and can achieve linear flow control within the 0-100% opening range. It has a temperature resistance of 550℃ and a pressure loss of less than or equal to 0.05 MPa. The second regulating valve 149 is installed on the pipeline between the second working fluid pump 146 and the supplementary heat network heater 143, and is used to dynamically regulate the flow rate of the hot heat storage medium entering the supplementary heat network heater 143. It is a key component for controlling the temperature of the heat network water during the heat release process. In this embodiment, the second regulating valve 149 can have the same structure and parameters as the first regulating valve 148, possess the same regulation accuracy and high temperature resistance, and support remote automatic control.

[0061] For example, during the system's heat storage process, the theoretical flow rate of the heat storage medium can be calculated based on the flue gas parameters used to heat the heat storage medium in the waste heat boiler 120 and the target outlet temperature of the heat storage medium, and the opening degree of the first regulating valve 148 can be further determined. During system operation, a temperature sensor can be set to monitor the temperature of the hot heat storage medium at the inlet of the second heat storage device 142 in real time. If the measured value is greater than a preset value (e.g., 500℃), the opening degree of the first regulating valve 148 is reduced to decrease the flow rate of the hot heat storage medium and reduce the heat exchange; if the measured value is less than the preset value, the opening degree of the first regulating valve 148 is increased to increase the flow rate of the hot heat storage medium until the temperature reaches the preset value. It is understood that the change in the opening degree of the first regulating valve 148 synchronously triggers the speed adjustment of the first working fluid pump 144 (e.g., the pump speed increases when the opening degree increases) so that the flow rate of the heat storage medium matches the valve's flow capacity, reducing valve vibration caused by "large valve, small flow".

[0062] During the system's heat release process, the required flow rate of the heat storage medium can be calculated based on the real-time demand of the heating network water, and the opening degree of the second regulating valve 149 can be further determined. During system operation, a temperature sensor can also be set to monitor the outlet temperature of the heating network water at the supplementary heating network heater 143. If the measured temperature is lower than the target temperature, the opening degree of the second regulating valve 149 is increased to increase the flow rate of the hot heat storage medium until the temperature reaches the target value; if the measured temperature is higher than the target temperature, the opening degree of the second regulating valve 149 is decreased to reduce the flow rate of the hot heat storage medium until the outlet heating network water temperature reaches the target temperature. It is understood that when the temperature of the heat storage medium at the outlet of the supplementary heating network heater 143 approaches its melting point (e.g., 210℃), the second regulating valve 149 automatically switches to "anti-condensation mode," forcibly maintaining an opening degree ≥50% (corresponding to a flow rate ≥40kg / s), thereby increasing the heat exchange efficiency by increasing the flow rate of the heat storage medium and preventing further temperature drops.

[0063] When the temperature of the flue gas used to heat the heat storage medium in the waste heat boiler 120 approaches the upper limit temperature value, the first regulating valve 148 will automatically reduce its opening, for example, reducing the opening to 30% closed, to reduce the flow rate of the heat storage medium and thus reduce the heat exchange intensity, preventing the heat storage medium from overheating and decomposing. Pressure sensors can also be installed before and after the first regulating valve 148. When the pressure difference exceeds the set pressure difference threshold (e.g., 0.1 MPa), it may indicate scale buildup on the valve core, requiring cleaning of the first regulating valve 148 to maintain valve flow performance. The second regulating valve 149 is equipped with a dual-motor drive module. When the main motor fails, the backup motor will automatically take over control within 50ms, ensuring uninterrupted heat release, which is especially suitable for peak winter heating periods.

[0064] It is understandable that the opening degree of the first regulating valve 148 The flow rate of the heat storage medium and the pressure difference across the regulating valve satisfy the relationship shown in equation (3):

[0065] (3)

[0066] In formula (3): The opening degree of the first regulating valve 148, The mass flow rate of the heat storage medium. The pressure difference of the heat storage medium before and after the first regulating valve 148, The density of the heat storage medium during the heat storage process is related to parameters such as valve type and valve size, and is determined based on the system commissioning situation.

[0067] The opening degree of the second regulating valve 149 is related to the flow rate of the heat storage medium and the pressure difference across the regulating valve as shown in the following equation (4):

[0068]

[0069] In the formula: For the opening degree of the second regulating valve 77, This refers to the mass flow rate of the heat storage medium during the heat release process. The pressure difference of the heat storage medium before and after the second regulating valve 149, The density of the heat storage medium during the heat release process is related to parameters such as valve type and valve size, and is determined based on the system commissioning situation.

[0070] In this embodiment, when the waste heat output of the fuel cell power generation system fluctuates, the amount of heat storage medium entering the waste heat boiler is controlled by adjusting the opening of the first regulating valve, and the heat supply flow can be dynamically adjusted according to the actual heat load gap by the second regulating valve. In this way, the precise control of the regulating valve makes the three links of waste heat recovery, heat storage and heat supply form a dynamic closed loop, which can efficiently utilize the waste heat stored during the off-peak period and release it during the peak period, and accurately match the heat load demand of the system.

[0071] In one embodiment, such as Figure 2 As shown, the waste heat boiler 120 includes a first flue, a second flue, and a third flue; the first flue is connected to a steam turbine 131 and a condenser 135, and is used to transport steam to the steam turbine 131 and receive water condensed from the steam in the condenser 135; the second flue is connected to a first heat storage device 141 and a second heat storage device 142, and is used to receive the heat storage medium in the first heat storage device 141 and to input the heated heat storage medium into the second heat storage device 142; the third flue is connected to a fuel power generation system 110, and is used to receive the flue gas generated by the fuel power generation system 110.

[0072] The waste heat boiler 120 is internally divided into three independent flues: a first flue, a second flue, and a third flue. Flue gas flow distribution in each flue can be adjusted via flue gas dampers to achieve graded utilization of thermal energy and synergistic heat storage. The first flue is responsible for steam generation, with a flue gas flow rate of 70%-90% (90% of the flue gas enters under normal operating conditions), used to heat water to produce steam. The second flue is a dedicated heat storage flue, with a flue gas flow rate of 0-30% (open only during heat storage), used to heat the heat storage medium. The third flue is open when not storing heat, with a flue gas flow rate of 10%-30% (if heat storage is closed, 100% of the flue gas is discharged through this flue), used to regulate the overall flue gas flow direction.

[0073] Specifically, in the flue gas heat exchange stage, the high-temperature, high-pressure flue gas generated by the fuel cell power generation system 110 enters the waste heat boiler 120 and releases heat in the first flue to heat the feedwater. The generated steam is input into the steam turbine 131. In the working fluid recovery stage, the low-temperature, low-pressure steam discharged from the steam turbine 131 is condensed into water in the condenser 135 and pressurized by the feedwater pump 134 before returning to the first flue of the waste heat boiler 120, completing the cycle. The second flue is the thermal energy interface between the waste heat boiler 120 and the heat storage subsystem 140. When the system electrical load is high and the thermal load is low, the system enters the heat storage mode. At this time, the second flue damper is opened to guide part of the flue gas into the second flue, while the remaining flue gas continues to exchange heat in the first flue. The cold heat storage medium of the first heat storage device 141 is sent into the second flue via the first working fluid pump 144 and the first regulating valve 148 to exchange heat with the high-temperature, high-pressure flue gas. After absorbing heat and heating up, the cold heat storage medium becomes a hot heat storage medium and flows into the second heat storage device 142 for storage. Under non-heat storage conditions, the second flue damper is closed, and all flue gas is discharged through the first and third flues to prevent overheating in the second flue due to the lack of heat storage medium flow. The third flue is a dynamic adjustment channel for flue gas flow. When the second flue is open for heat storage, the proportion of flue gas flow in the third flue = 100% - the proportion in the first flue - the proportion in the second flue. When the second flue is closed, the proportion of flue gas flow in the third flue = 100% - the proportion in the first flue. Therefore, the third flue is used to balance the load of the main flue to prevent overpressure in the first flue due to excessive flue gas volume and overheating in the second flue due to the lack of heat storage medium flow. It is understandable that when the internal pressure of the waste heat boiler 120 exceeds the upper pressure limit, the third flue damper will automatically open to quickly release the flue gas pressure and avoid tube rupture accidents.

[0074] In this embodiment, by designing and independently controlling multiple flues in the waste heat boiler, the steam flow rate of the first flue and the heat storage medium flow rate of the second flue are independently adjusted to achieve a dynamic balance between power generation, heating, and heat storage. The flue gas flow rate of the third flue is used to balance the pressure of the entire system, which can well match the changing demands of electrical and thermal loads in the distributed energy system and improve the heating capacity of the combined heat and power system.

[0075] In one embodiment, the system 100 further includes a first flue gas damper (not shown in the figures) disposed between the first flue and the steam power generation and heating subsystem 130, for regulating the amount of steam supplied by the waste heat boiler 120 to the steam power generation and heating subsystem 130.

[0076] The first flue gas damper is an adjustable damper valve installed between the outlet of the first flue of the waste heat boiler 120 and the steam power generation and heating subsystem 130. It can adjust the flow rate of flue gas entering the first flue by changing the cross-sectional area of ​​the flue gas flow, thereby indirectly controlling the amount of steam generated.

[0077] For example, when it is necessary to increase the steam intake of the steam turbine 131, the opening of the first flue gas damper can be increased to increase the flow rate of flue gas entering the first flue and thus increase steam production. During the adjustment process, the inlet steam temperature of the steam turbine 131 can be monitored by a temperature sensor. If the temperature is too high due to the increase in flue gas volume, the opening of the first flue gas damper can be appropriately reduced. The entire process can be adjusted based on an adaptive adjustment algorithm (such as a PID algorithm) to ensure that the steam parameters meet expectations. It is understood that the opening of the first flue gas damper is positively correlated with the opening of the steam flow regulating valve 136. For example, when the opening of the steam flow regulating valve 136 increases, the opening of the first flue gas damper increases synchronously, so that the steam flow rate matches the heat supply of the flue gas and avoids an unbalanced state of "steam without heat" or "heat without steam".

[0078] Furthermore, when the system's heat load demand increases, the flue gas volume can be increased first through the first flue gas damper to enhance steam production and increase steam extraction. If the electrical load exceeds the demand, the steam flow regulating valve 136 reduces the steam intake, using the excess steam for heating. When the electrical load demand increases, the flue gas volume can be maximized through the first flue gas damper to increase power generation. If the heat load is insufficient, the thermal storage subsystem 140 is activated to release heat for supplementary heating. Understandably, a minimum opening (e.g., 30%) can be set for the first flue gas damper to ensure the minimum cooling requirements of each heat exchange surface of the waste heat boiler 120, reducing the risk of tube wall overheating due to insufficient flue gas volume.

[0079] In this embodiment, by setting a flue gas baffle in the waste heat boiler, the energy can be used in stages and flexibly controlled, the strong correlation between thermal and electrical loads can be decoupled, the system's adaptability to load fluctuations and heating reliability can be enhanced, and the problem of insufficient heating capacity caused by low electrical load in traditional solutions can be effectively alleviated.

[0080] In one embodiment, the fuel power generation system 110 includes a reformer 111, a fuel cell 112, and a combustion chamber 113 connected in sequence. The reformer 111 pre-treats the fuel and then inputs the fuel into the anode of the fuel cell 112. The fuel cell 112 generates electricity through an electrochemical reaction between the fuel at the anode and the air at the cathode. The exhaust gas generated at the anode is input into the reformer, and the exhaust gas generated at the cathode is input into the combustion chamber 113. The combustion chamber 113 generates flue gas by burning the exhaust gas generated at the cathode.

[0081] The reformer 111 is used to pretreat fuel gas (such as natural gas or biomass gas) by converting large molecular hydrocarbons into small molecular gases suitable for the electrochemical reaction of the fuel cell through a reforming reaction. The fuel cell 112 generates electricity based on a solid oxide fuel cell, directly producing electrical energy through the electrochemical reaction between the anode fuel and the cathode air, while simultaneously generating anode exhaust gas (containing unreacted fuel, carbon dioxide, water vapor, etc.) and cathode exhaust gas (containing excess oxygen, nitrogen, etc.). The combustion chamber 113 is used to mix and burn the combustible components in the cathode exhaust gas and anode exhaust gas of the fuel cell 112, generating high-temperature flue gas as a heat source for the waste heat boiler 120.

[0082] For example, the fuel can be natural gas, biomass gas, or a mixed fuel. The fuel enters through the inlet of reformer 111, mixes with steam, and undergoes a steam reforming reaction under the action of a catalyst to generate reformed gas suitable for the electrochemical reaction of the fuel cell. This reformed gas is then input into the anode of fuel cell 112. In fuel cell 112, the reformed gas at the anode reacts with the air at the cathode to generate electricity through an electrochemical reaction. The unrecirculated portion of the exhaust gas at the cathode and the exhaust gas at the anode of fuel cell 112 mixes in combustion chamber 113 and undergoes a complete combustion reaction to produce high-temperature, high-pressure flue gas, which is then sent to waste heat boiler 120 as a heat source.

[0083] In this embodiment, the synergistic effect of the reformer and the fuel cell can improve the conversion efficiency of fuel chemical energy into electrical energy, and the recycling of waste gas can also improve the energy utilization rate. The waste heat of the high-temperature flue gas generated in the combustion chamber by the anode waste gas and cathode waste gas can be recovered by the waste heat boiler, realizing the combined heat and power of the system.

[0084] In one embodiment, such as Figure 3 As shown, this application provides a combined heat and power (CHP) control method, applied to the CHP system in any of the above embodiments, comprising the following steps:

[0085] S100 obtains the system's electrical load requirements and thermal load requirements.

[0086] S200, when the electrical load demand is less than the system's power generation, determines the amount of reduction in the steam flow entering the steam power generation and heating subsystem through a preset adaptive algorithm, and reduces the steam flow entering the steam power generation and heating subsystem according to the amount of reduction.

[0087] S300 reduces the amount of fuel and air input to the fuel cell power generation system when the power generation of the steam power generation and heating subsystem decreases to a preset electrical load threshold.

[0088] S400 adjusts the amount of steam used for heating in the steam power generation and heating subsystem based on the system's heat load demand, so that the heat output of the steam power generation and heating subsystem meets the system's heat load demand. If the heat output of the steam power generation and heating subsystem cannot meet the system's heat load demand, heat is released through the heated heat storage medium in the second heat storage device.

[0089] It should be noted that the solution provided by the method in this embodiment is similar to the solution described in the above method. Therefore, the specific limitations of one or more cogeneration control method embodiments provided below can be found in the limitations of the cogeneration system described above, and are only briefly explained here.

[0090] Among them, electrical load demand is the total amount of electricity consumed by all electrical devices connected to the system to operate normally within a specific time period, while heat load demand is the total amount of heat required by the system to meet heating demand within a certain time period.

[0091] For example, various sensors, metering devices, and data acquisition modules installed in the system can be used to monitor and acquire the current electrical load demand and heat load demand data of the system in real time. This data will be transmitted to the system's control center or server for further processing.

[0092] When the electrical load demand is less than the current system power generation, the system's power supply needs to be reduced. In this case, the steam flow rate of the steam power generation and heating subsystem can be reduced first to decrease the power supply from the steam power generation and heating subsystem. For example, the difference between the electrical load demand and the actual power generation can be calculated, and combined with the current steam inlet flow rate of the steam turbine, the PID algorithm can be used to calculate the amount of steam that should be reduced. By adjusting the steam flow regulating valve and the opening of the flue gas damper in the first flue, the amount of steam entering the steam power generation and heating subsystem can be reduced, and the amount of flue gas entering the first flue can also be reduced to maintain a stable steam inlet temperature for the steam turbine.

[0093] Furthermore, when the power generation of the steam power generation and heating subsystem decreases to a preset electrical load threshold—that is, when the power supply of the steam power generation and heating subsystem has decreased to the lower limit, but the electrical load demand is still relatively low—the fuel cell load reduction is initiated. For example, based on the load-fuel characteristics of the fuel cell, the input of fuel and air to the fuel cell power generation system is reduced.

[0094] In addition to meeting the electrical load requirements of the system, it is also necessary to meet the thermal load requirements. When the thermal load demand is high, the extraction steam flow regulating valve in the steam power generation and heating subsystem can be increased to increase the extraction steam volume, i.e., increase the amount of steam used for heating in the steam power generation and heating subsystem, so that the calorific value of the steam power generation and heating subsystem meets the system's thermal load requirements. However, the maximum extraction steam ratio of the steam power generation and heating subsystem is limited by the steam turbine flow rate (flow rate = inlet steam flow rate - extraction steam flow rate). Therefore, it is necessary to monitor the difference between the steam turbine inlet steam flow rate and the heating extraction steam flow rate. When the flow rate approaches the preset minimum flow rate of the steam turbine, the heating extraction steam volume cannot be increased further. If the extraction steam flow rate has been increased to the limit, but still cannot meet the system's thermal load requirements, heat can be released from the heated thermal storage medium in the second thermal storage device in the thermal storage subsystem.

[0095] It should be noted that when the liquid level of the second thermal storage device is lower than the preset minimum liquid level or the liquid level of the first thermal storage device is higher than the preset maximum liquid level, the thermal storage subsystem cannot be activated for heat replenishment because there is insufficient hot thermal storage medium that can release heat or there is no space to accommodate the cold thermal storage medium after heat release.

[0096] The aforementioned combined heat and power (CHP) control method, when the system's electrical load demand is less than its power generation, uses a preset adaptive algorithm to determine the reduction in steam flow into the steam power generation and heating subsystem. Based on this reduction, the steam flow into the subsystem is decreased, thereby reducing its power generation. When the power generation of the steam power generation and heating subsystem drops to a preset electrical load threshold, the amount of fuel and air entering the fuel cell power generation system is reduced, ensuring that the system's power generation matches the electrical load demand. Furthermore, since a reduction in system power generation often reduces system heat generation to some extent, the amount of steam used for heating in the steam power generation and heating subsystem is adjusted to ensure its heat generation meets the system's heat load demand. If the system's heat load demand is high and the heat generation of the steam power generation and heating subsystem cannot meet it, the heat stored in the heated heat storage medium in the heat storage subsystem can be utilized. By releasing the stored heat, the system's thermoelectricity can be decoupled, effectively solving the problem of insufficient system heat load supply.

[0097] In one embodiment, such as Figure 4 As shown, the method also includes:

[0098] S510, when the electrical load demand is greater than or equal to the preset rated electrical load and the heat load demand is less than the preset rated heat load, determine whether there is a heat storage medium in the first heat storage device and whether the second heat storage device is full.

[0099] S520, when there is a heat storage medium in the first heat storage device and the second heat storage device is not full, the heat storage medium in the first heat storage device is heated by a waste heat boiler.

[0100] The preset rated electrical load refers to the system's power supply capacity under full-load conditions, while the preset rated thermal load refers to the system's heating capacity under full-load conditions without supplemental heating. When supplemental heating is not activated, the system's power supply and heating are directly related. To meet the electrical load demand, the system will operate at full load. The heat generated at this time is the rated thermal load, which is greater than the actual thermal load demand of the system. In other words, the combined heat and power system generates excess heat at this time, which can be stored through the thermal storage subsystem.

[0101] Before activating the thermal storage subsystem, it is necessary to determine whether the first thermal storage unit contains cold thermal storage medium (e.g., if the storage level is less than 10% of the capacity, it can be considered that there is no cold thermal storage medium), and whether the second thermal storage unit is full of hot thermal storage medium (e.g., if the storage level exceeds 90% of the capacity, it can be considered that it is full of hot thermal storage medium). If the first thermal storage unit contains thermal storage medium and the second thermal storage unit is not full, the thermal storage medium in the first thermal storage unit can be heated by a waste heat boiler to store the excess heat in the system. This can avoid activating thermal storage when the thermal storage unit is in an abnormal state, reducing the possibility of thermal storage medium overflow or pump damage.

[0102] In this embodiment, the excess flue gas heat generated by the fuel cell during peak electrical load is used to heat the heat storage medium, storing the heat that might otherwise be wasted in the first heat storage device. This achieves thermoelectric decoupling in combined heat and power, enabling the power generation capacity to independently meet high electrical load demands. At the same time, it stores thermal energy for subsequent peak heat loads. By determining the status of the first and second heat storage devices before heat storage, the heat storage subsystem can operate efficiently within a safe capacity range, improving the safety and reliability of the system.

[0103] In one embodiment, such as Figure 4 As shown, S520 also includes:

[0104] S610, obtains the temperature of the heat storage medium in the waste heat boiler.

[0105] S620: When the difference between the temperature and the melting point of the heat storage medium is less than a preset difference threshold, the amount of heat storage medium entering the waste heat boiler is adjusted until the temperature of the heated heat storage medium reaches the preset temperature.

[0106] Taking binary molten salt as the heat storage medium as an example, the melting point of binary molten salt is 142℃. In this embodiment, the temperature of the heat storage medium needs to be kept at least 30℃ above the melting point to prevent solidification and blockage of the pipes. If the difference between the temperature of the heat storage medium in the waste heat boiler and the melting point of the heat storage medium is less than a preset difference threshold, the amount of heat storage medium entering the waste heat boiler can be adjusted using an adaptive algorithm, such as a PID algorithm. For example, reducing the amount of heat storage medium entering the waste heat boiler can prolong the residence time of the heat storage medium in the waste heat boiler and increase the temperature of the hot heat storage medium.

[0107] In this embodiment, during the heat storage process, by adjusting the amount of heat storage medium entering the waste heat boiler, the temperature of the heat storage medium can always be maintained above the melting point, thereby reducing the situation where the hot heat storage medium adheres to the pipe wall due to its low temperature, and improving the safety and reliability of the system.

[0108] To provide a clearer explanation of the combined heat and power control method provided in this application, the following is in conjunction with the appendix. Figure 4 and one A detailed embodiment will be explained, which includes the following steps:

[0109] S100 obtains the system's electrical load requirements and thermal load requirements.

[0110] S200, when the electrical load demand is less than the system's power generation, determines the amount of reduction in the steam flow entering the steam power generation and heating subsystem through a preset adaptive algorithm, and reduces the steam flow entering the steam power generation and heating subsystem according to the amount of reduction.

[0111] S300 reduces the amount of fuel and air input to the fuel cell power generation system when the power generation of the steam power generation and heating subsystem decreases to a preset electrical load threshold.

[0112] S400 adjusts the amount of steam used for heating in the steam power generation and heating subsystem based on the system's heat load demand, so that the heat output of the steam power generation and heating subsystem meets the system's heat load demand. If the heat output of the steam power generation and heating subsystem cannot meet the system's heat load demand, heat is released through the heated heat storage medium in the second heat storage device.

[0113] S510, when the electrical load demand is greater than or equal to the preset rated electrical load and the heat load demand is less than the preset rated heat load, determine whether there is a heat storage medium in the first heat storage device and whether the second heat storage device is full.

[0114] S520, when there is a heat storage medium in the first heat storage device and the second heat storage device is not full, the heat storage medium in the first heat storage device is heated by a waste heat boiler.

[0115] S610, obtains the temperature of the heat storage medium in the waste heat boiler.

[0116] S620: When the difference between the temperature and the melting point of the heat storage medium is less than a preset difference threshold, the amount of heat storage medium entering the waste heat boiler is adjusted until the temperature of the heated heat storage medium reaches the preset temperature.

[0117] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages of other steps.

[0118] Based on the same inventive concept, this application also provides a cogeneration control device for implementing the cogeneration control method described above. The solution provided by this device is similar to the solution described in the above method; therefore, the specific limitations in one or more cogeneration control device embodiments provided below can be found in the limitations of the cogeneration control method described above, and will not be repeated here.

[0119] In one embodiment, such as Figure 5 As shown, a combined heat and power (CHP) control device 300 is provided, including: a data acquisition module 310, a steam flow regulation module 320, a battery power generation regulation module 330, and a supplementary heat control module 340, wherein:

[0120] The data acquisition module 310 acquires the system's electrical load requirements and thermal load requirements.

[0121] The steam flow regulation module 320 is used to determine the amount of reduction in the steam flow entering the steam power generation and heating subsystem by means of a preset adaptive algorithm when the electrical load demand is less than the power generation of the system, and to reduce the steam flow entering the steam power generation and heating subsystem according to the amount of reduction.

[0122] The battery power generation regulation module 330 is used to reduce the amount of fuel and air input to the fuel cell power generation system when the power generation of the steam power generation and heating subsystem decreases to a preset electrical load threshold.

[0123] The supplementary heat control module 340 is used to adjust the amount of steam used for heating in the steam power generation and heating subsystem based on the system's heat load demand, so that the heat output of the steam power generation and heating subsystem meets the system's heat load demand. If the heat output of the steam power generation and heating subsystem cannot meet the system's heat load demand, heat is released through the heated heat storage medium in the second heat storage device.

[0124] In one embodiment, such as Figure 6 As shown, the combined heat and power control device 300 also includes a heat storage control module 350, which is used to determine whether there is a heat storage medium in the first heat storage device and whether the second heat storage device is full when the electrical load demand is greater than or equal to the preset rated electrical load and the heat load demand is less than the preset rated heat load. When there is a heat storage medium in the first heat storage device and the second heat storage device is not full, the heat storage medium in the first heat storage device is heated by a waste heat boiler.

[0125] In one embodiment, such as Figure 6 As shown, the combined heat and power control device 300 also includes a medium flow regulation module 360, which is used to obtain the temperature of the heat storage medium in the waste heat boiler. When the difference between the temperature and the melting point of the heat storage medium is less than a preset difference threshold, the amount of heat storage medium entering the waste heat boiler is adjusted until the temperature of the heated heat storage medium reaches the preset temperature.

[0126] Each module in the aforementioned combined heat and power control device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in the processor of a computer device in hardware form or independent of it, or stored in the memory of a computer device in software form, so that the processor can call and execute the corresponding operations of each module.

[0127] In one embodiment, a computer device is provided. The computer device may be a server, and its internal structure diagram may be as follows: Figure 7As shown, this computer device includes a processor, memory, input / output (I / O) interfaces, and a communication interface. The processor, memory, and I / O interfaces are connected via a system bus, and the communication interface is also connected to the system bus via the I / O interfaces. The processor provides computational and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system, computer programs, and a database. The internal memory provides the environment for the operating system and computer programs stored in the non-volatile storage media. The database stores data such as the system's heat load and electrical load requirements. The I / O interfaces are used for exchanging information between the processor and external devices. The communication interface is used for communication with external terminals via a network connection. When the computer program is executed by the processor, it implements a combined heat and power (CHP) control method.

[0128] Those skilled in the art will understand that Figure 7 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than shown in the figure, or combine certain components, or have a different component arrangement.

[0129] In one embodiment, a computer device is provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps described in the above-described cogeneration control system embodiment.

[0130] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the steps described in the embodiments of the combined heat and power control system.

[0131] In one embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps described in the above-described cogeneration control system embodiment.

[0132] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of related data must comply with the relevant laws, regulations and standards of the relevant countries and regions.

[0133] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the embodiments described above. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited to these.

[0134] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0135] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A combined heat and power system, characterized in that, The system includes a fuel cell power generation system and a waste heat boiler connected together, as well as a steam power generation and heating subsystem and a heat storage subsystem connected to the waste heat boiler. The steam power generation and heating subsystem includes a steam turbine connected to the waste heat boiler, and a generator and a heat network heater connected to the steam turbine. The heat storage subsystem includes a first heat storage device and a second heat storage device connected to the waste heat boiler, and a supplementary heat network heater connected to the second heat storage device. The supplementary heat network heater is connected to the heat network heater of the steam power generation and heating subsystem. The fuel cell power generation system generates electricity and produces flue gas based on an electrochemical reaction. The waste heat boiler heats water through the flue gas and inputs the generated steam into the steam turbine of the steam power generation and heating subsystem. The steam turbine uses part of the steam to drive the generator to supply electricity and draws part of the steam into the heating network heater for heating. When the heat energy generated by the steam power generation and heating subsystem is greater than or equal to the heat load demand of the system, the waste heat boiler also heats the heat storage medium transported by the first heat storage device through flue gas, and inputs the heated heat storage medium into the second heat storage device. When the heat energy generated by the steam power generation and heating subsystem is less than the heat load demand of the system, the heated heat storage medium in the second heat storage device is transported to the supplementary heating network heater for heating.

2. The system according to claim 1, characterized in that, The steam power generation and heating subsystem also includes a feedwater pump connected to the waste heat boiler, a condenser connected to the steam turbine, a steam flow regulating valve installed on the connecting pipe between the waste heat boiler and the steam turbine, and an extraction steam flow regulating valve installed on the connecting pipe between the steam turbine and the heating network heater. The feedwater pump is connected to the condenser. The condenser condenses the residual steam in the steam turbine into water, and the feedwater pump pumps the water formed by the condensation of the residual steam into the waste heat boiler. The steam flow regulating valve is used to regulate the amount of steam entering the steam turbine. The steam extraction flow regulating valve is used to regulate the amount of steam extracted into the heating network heater.

3. The system according to claim 1, characterized in that, A first working fluid pump and a first check valve are provided between the waste heat boiler and the first heat storage device. The first working fluid pump is used to pump the heat storage medium in the first heat storage device into the waste heat boiler for heating. A second working fluid pump and a second check valve are provided between the second thermal storage device and the supplementary heating network heater. The second working fluid pump is used to pump the heated thermal storage medium in the second thermal storage device into the supplementary heating network heater.

4. The system according to claim 3, characterized in that, The thermal storage subsystem further includes a first regulating valve disposed between the first working fluid pump and the waste heat boiler, and a second regulating valve disposed between the second working fluid pump and the supplementary heating network heater; The first regulating valve is used to regulate the amount of heat storage medium pumped into the waste heat boiler, and the second regulating valve is used to regulate the amount of heated heat storage medium pumped into the supplementary heating network heater.

5. The system according to claim 2, characterized in that, The waste heat boiler includes a first flue, a second flue, and a third flue; The first flue is connected to the steam turbine and the condenser, and is used to deliver steam to the steam turbine and receive water condensed from the steam in the condenser; The second flue is connected to the first heat storage device and the second heat storage device, and is used to receive the heat storage medium in the first heat storage device and to input the heated heat storage medium into the second heat storage device. The third flue is connected to the fuel-generating electronic system and is used to receive the flue gas generated by the fuel-generating electronic system.

6. The system according to claim 5, characterized in that, The system also includes a first flue gas damper disposed between the first flue and the steam power generation and heating subsystem, for adjusting the amount of steam supplied by the waste heat boiler to the steam power generation and heating subsystem.

7. The system according to claim 1, characterized in that, The fuel-to-electricity system includes a reformer, a fuel cell, and a combustion chamber connected in sequence. The reformer pre-treats the fuel and then inputs the fuel into the anode of the fuel cell. The fuel cell generates electricity through an electrochemical reaction between the fuel at the anode and the air at the cathode. The fuel cell also inputs the exhaust gas generated at the anode into the reformer and the exhaust gas generated at the cathode into the combustion chamber. The combustion chamber generates flue gas by burning the exhaust gas generated at the cathode.

8. A combined heat and power (CHP) control method, characterized in that, The method is applied to the combined heat and power system described in any one of claims 1 to 7, and the method includes: Obtain the electrical load and thermal load requirements of the system; When the electrical load demand is less than the power generation of the system, a preset adaptive algorithm is used to determine the amount of reduction in the steam flow rate entering the steam power generation and heating subsystem, and the steam flow rate entering the steam power generation and heating subsystem is reduced according to the amount of reduction. When the power generation of the steam power generation and heating subsystem decreases to a preset electrical load threshold, the input of fuel and air to the fuel cell power generation system is reduced. Based on the heat load demand of the system, the amount of steam used for heating in the steam power generation and heating subsystem is adjusted so that the heat output of the steam power generation and heating subsystem meets the heat load demand of the system. If the heat output of the steam power generation and heating subsystem cannot meet the heat load demand of the system, heat is released through the heated heat storage medium in the second heat storage device for heating.

9. The method according to claim 8, characterized in that, The method further includes: When the electrical load demand is greater than or equal to the preset rated electrical load and the heat load demand is less than the preset rated heat load, it is determined whether there is a heat storage medium in the first heat storage device and whether the second heat storage device is full. When the first heat storage device contains heat storage medium and the second heat storage device is not full, the heat storage medium in the first heat storage device is heated by the waste heat boiler.

10. The method according to claim 9, characterized in that, After heating the heat storage medium in the first heat storage device by the waste heat boiler, the method further includes: Obtain the temperature of the heat storage medium in the waste heat boiler; If the difference between the temperature and the melting point of the heat storage medium is less than a preset difference threshold, the amount of heat storage medium entering the waste heat boiler is adjusted until the temperature of the heated heat storage medium reaches the preset temperature.

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