Photovoltaic photo-thermal coupling distributed energy complementary energy supply system and method

Abstract

The invention provides a photovoltaic photo-thermal coupling distributed energy complementary energy supply system and method, and the system comprises a gas power generation system which comprises a gas turbine generator set. The waste heat boiler system comprises a waste heat boiler; the steam turbine power generation system comprises a steam turbine generator set; the photovoltaic and photo-thermal power generation system comprises a photovoltaic and photo-thermal integrated device; the waste heat exchange system comprises a first heat exchange device and a second heat exchange device; according to the system, energy flow between systems is optimized in a heat energy recovery and multi-energy coupling mode, the energy utilization efficiency is improved, and the operation cost is reduced. According to the invention, waste heat of the back plate of the photovoltaic module is utilized to preheat natural gas at an inlet of the gas turbine and make-up water of the waste heat boiler in advance, so that the problems of a cooling cold source of the back plate of the photovoltaic module and freezing prevention in a low-temperature environment are solved, and the problems of corrosion of a turbine nozzle of the gas turbine and low-temperature corrosion of a boiler mortgage economizer are solved; waste heat generated by the photovoltaic module is deeply coupled with the natural gas heating system and the waste heat boiler feed water waste heat system.

Description

Technical Field

[0001] The present invention relates to the technical field of efficient energy utilization, and in particular to a photovoltaic-thermal coupled distributed energy complementary energy supply system and method. Background Art

[0002] With the promotion of new energy systems and clean energy, photovoltaic power generation systems and distributed energy supply systems have been widely used. Distributed energy supply systems are widely used in commercial and residential energy supply due to their high energy utilization efficiency and low environmental pollution. However, both systems have certain limitations when operating independently. Photovoltaic systems generate a lot of waste heat during the power generation process, and this waste heat is usually not effectively utilized; distributed energy supply systems require a lot of preheating heat sources during operation. Both systems have problems such as insufficient waste heat utilization or unsatisfactory heat dissipation, which affect equipment life and low system efficiency when operating alone.

[0003] In a gas-fired distributed energy supply system that uses natural gas as the main fuel, natural gas usually contains sulfur and water vapor. Especially under low ambient temperature conditions, the natural gas temperature is often lower than its dew point temperature. If it operates under such conditions for a long time, it will usually cause the working conditions of the gas turbine gas fuel nozzle to deteriorate, causing corrosion of the gas turbine turbine nozzle. At the same time, if the feed water inlet temperature of the waste heat boiler in the system is too low, it will also cause low-temperature corrosion of the low-pressure economizer, affecting the equipment life and energy supply efficiency. In order to solve the corrosion problem of the gas turbine turbine nozzle and the boiler low-pressure economizer, the current system usually needs to configure additional heating measures to preheat the inlet natural gas and boiler feed water, which has a certain impact on the efficiency of the entire energy supply system and has a high operating cost.

[0004] During the operation of the photovoltaic power generation system, the increase in the temperature of the backplane of the photovoltaic module will lead to a decrease in the conversion efficiency of the photovoltaic cell and affect the output power of the photovoltaic module. In cold areas, photovoltaic modules also have the problem of low-temperature cracking. Taking crystalline silicon modules as an example, although the theoretical limit of the photoelectric conversion efficiency of crystalline silicon solar cells is close to 30%, in fact, the conversion efficiency of crystalline silicon modules is only about 20%. The module only converts a small part of the absorbed solar energy into electrical energy for use, while most of the remaining energy is converted into heat energy and wasted. Moreover, the heat energy cannot be completely dissipated, which will cause the temperature of the photovoltaic module to rise, and have an adverse effect on the power generation efficiency of the module. Similar problems also exist for solar cells or photovoltaic modules made of other materials. Every 1°C increase in the operating temperature of crystalline silicon solar cells will lead to a 0.4% to 0.5% reduction in output power. Since more than 80% of the energy reaching the surface of the cell is converted into heat, the operating temperature of the solar cell is usually above 50°C, and even reaches 80°C when the heat dissipation is poor, which will seriously affect the working efficiency of the solar cell. Photovoltaic modules not only reduce their efficiency in high temperature environments, but are also susceptible to freezing in low temperature environments. Therefore, the heat dissipation and low-temperature antifreeze of the backplane of photovoltaic modules are crucial to the performance and stability of photovoltaic power generation systems. Summary of the invention

[0005] The purpose of the present invention is to provide a photovoltaic-thermal coupled distributed energy complementary energy supply system and method, which not only solves the problem of preheating heat source in the gas distributed energy supply system by reusing the waste heat generated by the photovoltaic system, but also improves and broadens the operating conditions of the photovoltaic components, improves the overall power generation efficiency of the system, reduces the risk of equipment corrosion, and achieves efficient use of energy and environmental benefits.

[0006] According to one object of the present invention, the present invention provides a photovoltaic-thermal coupled distributed energy complementary energy supply system, including a gas power generation system, a waste heat boiler system, a steam turbine power generation system, a photovoltaic-thermal power generation system and a waste heat heat exchange system, wherein the gas power generation system includes a gas turbine generator set, the waste heat boiler system includes a waste heat boiler, the steam turbine power generation system includes a steam turbine generator set, the photovoltaic-thermal power generation system includes a photovoltaic-thermal integrated device, and the waste heat heat exchange system includes a first heat exchange device and a second heat exchange device;

[0007] The gas turbine generator set is connected to the waste heat boiler, and the high-temperature flue gas discharged after combustion by the gas turbine generator set enters the waste heat boiler for step-by-step heat exchange;

[0008] The waste heat boiler is connected to the steam turbine generator set. The high-pressure steam generated by flue gas heat exchange in the waste heat boiler enters the steam turbine generator set through a pipeline to drive the steam turbine to generate electricity. The generated low-pressure steam enters the steam inlet of the steam turbine generator set through a pipeline to generate electricity, or is collected in the heating pipeline to supply heat to users.

[0009] The steam turbine generator set is connected to the condenser and the water tank, the condenser and the water tank are connected to the condensate pump through pipelines, the condensate pump is connected to the waste heat boiler through pipelines, the high and low pressure steam passes through the steam turbine generator set to generate power and provide heat, and the remaining exhaust steam enters the condenser, is cooled by circulating water, and condenses into water, and then is driven by the condensate pump and sent back to the waste heat boiler;

[0010] The photovoltaic-thermal integrated device is connected to the first heat exchange device, and the first heat exchange device is respectively connected to the desalted water supply water pipeline and the condenser water tank; the photovoltaic-thermal integrated device is connected to the second heat exchange device, and the second heat exchange device is respectively connected to the natural gas pipeline and the gas turbine generator set.

[0011] Furthermore, the gas turbine generator set is connected to a fuel processing system, and natural gas is filtered and regulated by the fuel processing system before entering the gas turbine generator set and being mixed with air for combustion.

[0012] Furthermore, the photovoltaic-thermal integrated device is connected to the first heat exchange device through a pipeline and a first valve, the first heat exchange device is connected to the second valve, the second valve is connected to a circulation pump, the first heat exchange device is connected to the desalted water supply water pipeline through a third valve, and the desalted water pipeline heated by the first heat exchange device is connected to the ninth valve and the condenser and the water tank.

[0013] Furthermore, the photovoltaic-thermal integrated device is connected to the second heat exchange device through a pipeline and a fourth valve, the second heat exchange device is connected to a fifth valve, and the fifth valve is connected to the circulation pump; the second heat exchange device is connected to the natural gas pipeline through a sixth valve, and the natural gas pipeline heated by the second heat exchange device is connected to the gas turbine generator set through a seventh valve.

[0014] Furthermore, the natural gas pipeline heated by the second heat exchange device is connected to the fuel processing system in front of the gas turbine generator set through the seventh valve.

[0015] Furthermore, the electricity generated by the photovoltaic-thermal integrated device is connected to the power system or power consumption unit through cables and a DC / AC inverter device together with the electricity generated by the gas turbine generator set and the steam turbine generator set.

[0016] Furthermore, when the water quality of the boiler feed water and the cooling water source of the photovoltaic thermal integration device is different, the first heat exchange device adopts an indirect heat exchange device, and the second heat exchange device adopts a heat exchange device with a gas-water separation structure, and the natural gas and water enter different heat exchange tubes for heat exchange respectively.

[0017] Furthermore, the photothermal conversion device includes a photothermal absorption layer, a backplane heat exchange device and a control system, which are used to convert the absorbed heat into thermal energy to provide a preheating heat source for the gas distributed energy supply system.

[0018] According to the second object of the present invention, the present invention provides a method for using the above photovoltaic-thermal coupled distributed energy complementary energy supply system, comprising the following steps:

[0019] S1. The gas turbine generator set sends the high-temperature flue gas discharged after combustion into the waste heat boiler for step-by-step heat exchange. The waste heat boiler is connected to the steam turbine generator set. The high-pressure steam generated by the flue gas heat exchange in the waste heat boiler enters the steam turbine generator set through a pipeline to drive the steam turbine to generate electricity. The generated low-pressure steam enters the steam inlet of the steam turbine generator set through a pipeline to generate electricity, or is collected into the heating pipeline to supply heat to users;

[0020] S2. The steam turbine generator set is connected to the condenser and the water tank. The condenser and the water tank are connected to the condensate pump through pipelines. The condensate pump is connected to the waste heat boiler through pipelines. The high and low pressure steam after the steam turbine generator set generates power and supplies heat enters the condenser. After being cooled by circulating water, it condenses into water, and then is driven by the condensate pump to be sent back to the waste heat boiler to achieve water recycling.

[0021] S3, the photovoltaic-thermal integrated device converts part of the solar energy into electrical energy by absorbing the solar energy, and connects to the power system through the cable via the DC / AC inverter device, and exchanges the remaining solar energy with the internal circulating cooling medium through the photothermal conversion device, and the heated circulating cooling medium enters the primary side of the first heat exchange device for heat exchange, forming the first heat exchange cycle;

[0022] S4. The desalted water replenishment water enters the secondary side of the first heat exchange device to exchange heat with the circulating cooling medium in the photovoltaic thermal system, and the desalted water replenishment water temperature is heated. The desalted water replenishment water system is preheated in advance after passing through the photovoltaic thermal system, and the photovoltaic components are cooled at the same time. The preheated desalted water is mixed with the condensate water system, and then replenished into the waste heat boiler system through the condensate water pump.

[0023] Furthermore, the circulating cooling medium in the photovoltaic-thermal integrated device enters the primary side of the second heat exchange device, undergoes secondary heat exchange with the natural gas from the pressure regulating station, and the natural gas heated by the second heat exchange device enters the gas turbine generator set through a pipeline.

[0024] The technical solution of the present invention reuses the waste heat generated by the photovoltaic power generation system, couples the waste heat generated by the photovoltaic module with the natural gas heating system and the waste heat boiler feed water preheating system, fully utilizes the waste heat of the photovoltaic system, realizes the cooling of the photovoltaic module backplane, the advance preheating of the natural gas system and the boiler feed water, and also solves the antifreeze problem of the photovoltaic module in a low-temperature environment, and also solves the problems of corrosion of the gas turbine turbine nozzle and low-temperature corrosion of the boiler low-pressure economizer, and realizes the dual improvement of the power generation efficiency of the gas turbine generator set and the photovoltaic module; at the same time, it saves the heating amount of the waste heat boiler recirculation system, reduces the design capacity of the boiler recirculation heating system and the initial investment of the natural gas heating system, greatly reduces the operating cost of the system, realizes the deep coupling of photovoltaic thermal energy and gas distributed energy system, and improves the energy utilization rate and environmental protection benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0026] Figure 1 It is a structural schematic diagram of an embodiment of the present invention;

[0027] In the figure: 1. gas turbine generator set; 101. fuel processing system; 2. waste heat boiler; 3. steam turbine generator set; 4. condenser; 5. condensate pump; 6. photovoltaic thermal integration device; 601. photothermal conversion device; 7. first heat exchange device; 8. second heat exchange device; 9. circulation pump; 10. first valve; 11. second valve; 12. third valve; 13. fourth valve; 14. fifth valve; 15. sixth valve, 16. seventh valve; 17. eighth valve; 18. ninth valve; 19. DC / AC inverter; 20. heating pipeline supplies heat to users; 21. power system or power consumption unit. DETAILED DESCRIPTION

[0028] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0030] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "multiple" means two or more, unless otherwise clearly and specifically defined. In addition, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0031] Example 1

[0032] like Figure 1 As shown,

[0033] A photovoltaic-thermal coupled distributed energy complementary energy supply system, comprising a gas power generation system, a waste heat boiler system, a steam turbine power generation system, a photovoltaic-thermal power generation system and a waste heat exchange system, wherein:

[0034] The gas power generation system includes a gas turbine generator set 1 and a fuel processing system 101, the waste heat boiler system includes a waste heat boiler 2, the steam turbine power generation system includes a steam turbine generator set 3, the photovoltaic thermal power generation system includes a photovoltaic thermal integration device 6 and a photothermal conversion device 601, and the waste heat heat exchange system includes a first heat exchange device 7 and a second heat exchange device 8.

[0035] The gas turbine generator set 1 is connected to the waste heat boiler 2. The high-temperature flue gas discharged after combustion in the gas turbine generator set 1 enters the waste heat boiler 2 for step-by-step heat exchange. At the same time, the gas turbine generator set 1 is also connected to the fuel processing system 101. The natural gas enters the gas turbine generator set 1 and is mixed with air for combustion after being filtered and regulated by the fuel processing system 101.

[0036] The waste heat boiler 2 is connected to the steam turbine generator set 3. The high-pressure steam generated by the flue gas heat exchange in the waste heat boiler 2 enters the steam turbine generator set 3 through a pipeline to drive the steam turbine to generate electricity. The generated low-pressure steam enters the steam supply port of the steam turbine generator set 3 through a pipeline to generate electricity, or is merged into the heating pipeline to supply heat to the heat user 20. Different methods are selected according to actual conditions.

[0037] The steam turbine generator set 3 is connected to the condenser 4 and the water tank, and the condenser 4 and the water tank are connected to the condensate pump 5 through a pipeline, and then the condensate pump 5 is connected to the waste heat boiler 2 through a pipeline. The high and low pressure steam passes through the steam turbine generator set 3 to generate electricity and provide heat, and the remaining exhaust steam enters the condenser 4 and the water tank, is condensed into water after being cooled by circulating water, and is then sent back to the waste heat boiler 2 by the drive of the condensate pump 5, so as to realize the recycling of water.

[0038] The photovoltaic thermal integrated device 6 in the photovoltaic thermal power generation system is connected to the first heat exchange device 7 through a pipeline and a first valve 10, the first heat exchange device 7 is connected to the second valve 11, the second valve 11 is connected to the circulation pump 9, the first heat exchange device 7 is connected to the desalted water supply water pipeline through the third valve 12, and the desalted water pipeline heated by the first heat exchange device 7 is connected to the ninth valve 18, the condenser 4 and the water tank.

[0039] The photovoltaic-thermal integrated device 6 is also connected to the second heat exchange device 8 through a pipeline and a fourth valve 13, the second heat exchange device 8 is connected to a fifth valve 14, and the fifth valve 14 is connected to a circulation pump 9; the second heat exchange device 8 is connected to a natural gas pipeline through a sixth valve 15, and the natural gas pipeline heated by the second heat exchange device 8 is connected to a fuel processing system 101 in front of the gas turbine generator set 1 through a seventh valve 16. In order to consider the maintenance of the heat exchange device and the operation under conditions that do not require heating, a bypass system is set up, and an eighth valve 17 is provided in the bypass system.

[0040] When the water quality of the boiler feed water and the cooling water source of the photovoltaic thermal integration device is different, the first heat exchange device 7 can adopt an indirect heat exchange device, and the second heat exchange device 8 can adopt a heat exchange device with a gas-water separation structure, and the natural gas and water enter different heat exchange tubes for heat exchange respectively.

[0041] The electricity generated by the photovoltaic-thermal integrated device 6 is connected to the power system or power consumption unit 21 through cables and a DC / AC inverter 19 together with the electricity generated by the gas turbine generator set 1 and the steam turbine generator set 3 .

[0042] When the photovoltaic-thermal coupled distributed energy complementary energy supply system of the present invention is working:

[0043] The gas turbine generator set 1 passes the high-temperature flue gas exhausted after combustion into the waste heat boiler 2 for step-by-step heat exchange. The waste heat boiler 2 is connected to the steam turbine generator set 3. The high-pressure steam generated by the flue gas heat exchange in the waste heat boiler 2 enters the steam turbine generator set 3 through a pipeline to drive the steam turbine to generate electricity. The generated low-pressure steam enters the steam supply port of the steam turbine generator set through a pipeline to generate electricity, or is merged into the heating pipeline to supply heat to the heat user 20. Different methods are selected according to actual needs.

[0044] The steam turbine generator set 3 is connected to the condenser 4 and the water tank, and the condenser 4 and the water tank are connected to the condensate pump 5 through a pipeline, and then the condensate pump 5 is connected to the waste heat boiler 2 through a pipeline. The high and low pressure steam passes through the steam turbine generator set 3 to generate power and provide heat, and the remaining exhaust steam enters the condenser, is cooled by circulating water, and is condensed into water, and then driven by the condensate pump 5 to be sent back to the waste heat boiler 2, so as to realize the recycling of water;

[0045] The photovoltaic-thermal integrated device 6 converts part of the solar energy into electrical energy (20% to 25%) by absorbing the heat of the solar energy, and is connected to the power system 21 through a cable via a DC / AC inverter 19. The remaining solar energy heat is exchanged with the internal circulating cooling medium (which can be water or refrigerant, selected according to the external ambient temperature) through a photothermal conversion device 601 (the type of heat exchange device is not limited to tubular or plate type). The heated circulating cooling medium enters the primary side of the first heat exchange device 7 through the pipeline and the first valve 10 in turn for heat exchange, forming the first heat exchange cycle. The circulating pump 9 provides circulation power for the circulating cooling medium to further achieve the effect of cooling the photovoltaic module.

[0046] In summer or in areas with high temperatures, softened water can be used as the circulating cooling medium in photovoltaic thermal systems; in cold areas or areas with low temperatures in winter, antifreeze can be used as the circulating cooling medium;

[0047] The desalted water (the feed water temperature is generally 10°C-20°C, affected by the season and ambient temperature) introduced after being treated by the water treatment system enters the secondary side of the first heat exchange device 7 through the pipeline and the third valve 12 to exchange heat with the circulating cooling medium in the photovoltaic thermal system, thereby heating the desalted water. The desalted water make-up system is preheated in advance after passing through the photovoltaic thermal system, and the photovoltaic components are also cooled. The preheated desalted water is connected to the condenser 4 and the water tank through the ninth valve 18 and the pipeline to be mixed with the condensate system, and then is replenished into the waste heat boiler system through the condensate pump 5, thereby increasing the inlet water temperature of the low-pressure economizer, preventing low-temperature corrosion of the low-pressure economizer, and reducing the heat consumption and operating costs of the original system by fully recycling and utilizing solar energy waste heat.

[0048] The present invention utilizes the waste heat from the back panel of the photovoltaic module to preheat the feed water at the inlet of the waste heat boiler in advance. On the one hand, it saves the heating amount of the waste heat boiler recirculation system and can reduce the design capacity of the boiler recirculation system. At the same time, it also solves the cooling source of the back panel of the photovoltaic module and improves the power generation output of the photovoltaic module. It fully combines the heat dissipation of the back panel of the photovoltaic module with the boiler inlet water temperature increase system for coupling, bringing a double effect.

[0049] At the same time, the circulating cooling medium in the photovoltaic-thermal integrated device 6 can also enter the primary side of the second heat exchange device 8 through the pipeline and the fourth valve 13, and perform secondary heat exchange with the natural gas (12-20°C) from the pressure regulating station. The natural gas pipeline heated by the second heat exchange device 8 is connected to the fuel processing system 101 in front of the gas turbine generator set 1 through the seventh valve 16. In order to consider the maintenance of the heat exchange device and the operation under conditions that do not require heating, a bypass system is set up, and an eighth valve 17 is provided in the bypass system. The system can heat the temperature of natural gas to above 35°C-40°C, so that the natural gas is higher than the dew point temperature, so as to avoid corrosion of the gas fuel nozzle of the gas engine by sulfur and water vapor in the natural gas. It can replace the existing electric heating, gas water bath heating, hot water or steam heat exchanger heating, etc., saving the operating cost of natural gas heating. When the natural gas heating temperature is increased to above 40°C, the power generation output of the gas turbine can be increased by about 0.5%.

[0050] In this embodiment, the photovoltaic module is used to generate electricity, and its back panel is designed with a light-heat absorption layer for absorbing solar energy heat.

[0051] The photothermal conversion device 601 includes a photothermal absorption layer, a back plate heat exchange device and a control system, which is used to convert the absorbed heat into thermal energy to provide preheating for the gas distributed energy supply system.

[0052] When the waste heat of the photovoltaic thermal device is insufficient, it can be satisfied by increasing the installed capacity of the integrated photovoltaic thermal device, which can also improve the utilization ratio and absorption rate of renewable energy.

[0053] When the water quality of the boiler feed water and the cooling water source of the photovoltaic thermal integration device is different, the first heat exchange device 7 can adopt an indirect heat exchange device, and the second heat exchange device 8 can adopt a heat exchange device with a gas-water separation structure, and the natural gas and water enter different heat exchange tubes for heat exchange respectively.

[0054] When the ambient temperature is high in summer or the desalted water replenishment flow is low, the fourth valve 13 can be opened to enter the second heat exchange device 8 for a second cooling and heat exchange with natural gas. Through two heat exchange cycles, the cooling effect of the photovoltaic panel can be further guaranteed, ensuring that the temperature of the photovoltaic panel drops below 30°C throughout the year, so that the power generation performance of the photovoltaic module is always in the optimal working condition, thereby improving the overall efficiency of the photovoltaic power generation system.

[0055] The present invention also includes a control system, which is used to monitor and adjust the operation of the entire system. By monitoring the operating status of each system, the operating conditions of each system are adjusted in real time to achieve optimal utilization of energy.

[0056] The first effect of the implementation of the present invention is to solve the problem of cooling the back panel of the photovoltaic module, and to deeply couple and complement the gas distributed system. While solving the problem of cooling the back panel of the photovoltaic module, it also realizes the recovery and utilization of solar energy heat, and controls the temperature of the back panel of the photovoltaic module below 30°C. Compared with the existing photovoltaic module back panel cooling technology, it saves the initial investment and operating costs of the cooling system, and improves the photovoltaic power generation efficiency by more than 10%.

[0057] The second effect of the implementation of the present invention is that it solves the problem of gas turbine corrosion caused by sulfur and water vapor in natural gas in the gas distributed energy system, uses the heat generated by the photovoltaic module as a heat source for heating the natural gas, and the natural gas is used as a cooling source for cooling the back panel of the photovoltaic module. Through multi-energy complementarity and temperature gradient utilization, the utilization rate of solar energy is improved, the investment and operation costs of the entire system are saved, and the power generation output of the gas turbine is improved while heating the inlet natural gas temperature.

[0058] The third implementation effect of the present invention: The present invention solves the problem of severe low-temperature corrosion of the low-pressure economizer of the waste heat boiler in the gas-fired distributed energy system and the heat source for preheating the feed water of the waste heat boiler, and uses the waste heat of the backplate of the photovoltaic module to preheat the inlet feed water of the waste heat boiler in advance. On the one hand, it saves the heating amount of the waste heat boiler recirculation system and can reduce the design capacity of the recirculation system. At the same time, it also solves the cooling source of the backplate of the photovoltaic module and improves the power generation output of the photovoltaic module. It fully combines the heat dissipation of the backplate of the photovoltaic module with the boiler inlet water temperature increase system for coupling, bringing a double effect.

[0059] The present invention provides a photovoltaic-thermal coupled distributed energy complementary energy supply system and method. The system reuses the waste heat generated by the photovoltaic system, which can not only solve the problem of early preheating of the natural gas heating heat source and the waste heat boiler feed water system of the gas distributed energy supply system, but also solve the problem of cooling the back panel of the photovoltaic module and antifreezing in a low temperature environment, and also solve the problem of corrosion of the gas turbine turbine nozzle and low-temperature corrosion of the boiler low-pressure economizer, thereby achieving a double improvement in the power generation efficiency of the gas turbine and the photovoltaic module; at the same time, the waste heat generated by the photovoltaic module is coupled with the natural gas heating system and the waste heat boiler feed water preheating system, and the waste heat of the photovoltaic module back panel is fully utilized, and the cooling of the photovoltaic module back panel and the heating of the natural gas and boiler feed water are achieved, which greatly reduces the operating cost of the system, and at the same time improves the power generation performance of the photovoltaic module, and realizes the deep coupling of photovoltaic-thermal and gas distributed energy systems, with high energy utilization and high environmental benefits.

[0060] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A photovoltaic-thermal coupled distributed energy complementary energy supply system, characterized in that: It includes a gas power generation system, a waste heat boiler system, a steam turbine power generation system, a photovoltaic thermal power generation system and a waste heat heat exchange system, wherein the gas power generation system includes a gas turbine generator set, the waste heat boiler system includes a waste heat boiler, the steam turbine power generation system includes a steam turbine generator set, the photovoltaic thermal power generation system includes a photovoltaic thermal integrated device, and the waste heat heat exchange system includes a first heat exchange device and a second heat exchange device; The gas turbine generator set is connected to the waste heat boiler, and the high-temperature flue gas discharged after combustion by the gas turbine generator set enters the waste heat boiler for step-by-step heat exchange; The waste heat boiler is connected to the steam turbine generator set. The high-pressure steam generated by flue gas heat exchange in the waste heat boiler enters the steam turbine generator set through a pipeline to drive the steam turbine to generate electricity. The generated low-pressure steam enters the steam inlet of the steam turbine generator set through a pipeline to generate electricity, or is collected in the heating pipeline to supply heat to users. The steam turbine generator set is connected to the condenser and the water tank, the condenser and the water tank are connected to the condensate pump through pipelines, the condensate pump is connected to the waste heat boiler through pipelines, the high and low pressure steam passes through the steam turbine generator set to generate power and provide heat, and the remaining exhaust steam enters the condenser, is condensed into water after being cooled by circulating water, and then is sent back to the waste heat boiler through the drive of the condensate pump; The photovoltaic-thermal integrated device is connected to the first heat exchange device, and the first heat exchange device is respectively connected to the desalted water supply water pipeline and the condenser; the photovoltaic-thermal integrated device is connected to the second heat exchange device, and the second heat exchange device is respectively connected to the natural gas pipeline and the gas turbine generator set.

2. The photovoltaic-thermal coupled distributed energy complementary energy supply system according to claim 1 is characterized in that: The gas turbine generator set is connected to a fuel processing system, and natural gas is filtered and regulated by the fuel processing system before entering the gas turbine generator set to be mixed with air for combustion.

3. The photovoltaic-thermal coupled distributed energy complementary energy supply system according to claim 2 is characterized in that: The photovoltaic-thermal integration device is connected to the first heat exchange device through a pipeline and a first valve, the first heat exchange device is connected to the second valve, the second valve is connected to a circulation pump, the first heat exchange device is connected to the desalted water supply water pipeline through a third valve, and the desalted water pipeline heated by the first heat exchange device is connected to the ninth valve and the condenser and the water tank.

4. The photovoltaic-thermal coupled distributed energy complementary energy supply system according to claim 3 is characterized in that: The photovoltaic-thermal integrated device is connected to the second heat exchange device through a pipeline and a fourth valve, the second heat exchange device is connected to a fifth valve, and the fifth valve is connected to the circulation pump; the second heat exchange device is connected to a natural gas pipeline through a sixth valve, and the natural gas pipeline heated by the second heat exchange device is connected to the gas turbine generator set through a seventh valve.

5. The photovoltaic-thermal coupled distributed energy complementary energy supply system according to claim 4 is characterized in that: The natural gas pipeline heated by the second heat exchange device is connected to the fuel processing system in front of the gas turbine generator set through the seventh valve.

6. The photovoltaic-thermal coupled distributed energy complementary energy supply system according to claim 1 is characterized in that: The electricity generated by the photovoltaic-thermal integrated device is connected to the power system or power consumption unit through cables and DC / AC inverters as well as the electricity generated by the gas turbine generator set and the steam turbine generator set.

7. The photovoltaic-thermal coupled distributed energy complementary energy supply system according to claim 1 is characterized in that: When the water quality of the boiler feed water and the cooling water source of the photovoltaic thermal integration device is different, the first heat exchange device adopts an indirect heat exchange device, and the second heat exchange device adopts a heat exchange device with a gas-water separation structure, and the natural gas and water enter different heat exchange tubes for heat exchange respectively.

8. The photovoltaic-thermal coupled distributed energy complementary energy supply system according to claim 1 is characterized in that: The photovoltaic-thermal integrated device includes a photothermal conversion device, which includes a photothermal absorption layer, a backplane heat exchange device and a control system, and is used to convert the absorbed heat into thermal energy to provide preheating for the gas distributed energy supply system.

9. The method for using the photovoltaic-thermal coupled distributed energy complementary energy supply system according to claim 1, characterized in that: The steps include: S1. The gas turbine generator set sends the high-temperature flue gas discharged after combustion into the waste heat boiler for step-by-step heat exchange. The waste heat boiler is connected to the steam turbine generator set. The high-pressure steam generated by the flue gas heat exchange in the waste heat boiler enters the steam turbine generator set through a pipeline to drive the steam turbine to generate electricity. The generated low-pressure steam enters the steam inlet of the steam turbine generator set through a pipeline to generate electricity, or is collected into the heating pipeline to supply heat to users; S2. The steam turbine generator set is connected to the condenser and the water tank. The condenser and the water tank are connected to the condensate pump through pipelines. The condensate pump is connected to the waste heat boiler through pipelines. The high and low pressure steam after the steam turbine generator set generates power and supplies heat enters the condenser. After being cooled by circulating water, it condenses into water, and then is driven by the condensate pump to be sent back to the waste heat boiler to achieve water recycling. S3, the photovoltaic-thermal integrated device converts part of the solar energy into electrical energy by absorbing the solar energy, and connects to the power system through the cable via the DC / AC inverter device, and exchanges the remaining solar energy with the internal circulating cooling medium through the photothermal conversion device, and the heated circulating cooling medium enters the primary side of the first heat exchange device for heat exchange, forming the first heat exchange cycle; S4. The desalted water replenishment water enters the secondary side of the first heat exchange device to exchange heat with the circulating cooling medium in the photovoltaic thermal system, and the desalted water replenishment water temperature is heated. The desalted water replenishment water system is preheated in advance after passing through the photovoltaic thermal system, and the photovoltaic components are cooled at the same time. The preheated desalted water is mixed with the condensate water system, and then replenished into the waste heat boiler system through the condensate water pump.

10. The method for using the photovoltaic-thermal coupled distributed energy complementary energy supply system according to claim 9, characterized in that: The circulating cooling medium in the photovoltaic and thermal integration device enters the primary side of the second heat exchange device and undergoes secondary heat exchange with the natural gas from the pressure regulating station. The natural gas heated by the second heat exchange device enters the gas turbine generator set through a pipeline.

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