A Photovoltaic Cover Plate and Energy Conversion System for Recycling Waste Heat from Power Generation

Abstract

The present invention discloses a photovoltaic cover plate and an energy conversion system capable of recovering waste heat for power generation, belonging to the technical field of energy-saving cover plates. The photovoltaic cover plate includes a cover plate unit and an exhaust fan; the cover plate unit includes a body, a photovoltaic panel and a sealing structure; the body extends in the left-right direction, and an installation platform is provided thereon; the photovoltaic panels are arranged at intervals in the left-right direction, and the front and rear ends thereof are respectively connected to the installation platform; the sealing structure is arranged at the left and right ends of the body and jointly encloses a relatively closed heat collection cavity with the photovoltaic panel and the body; the heat collection cavity extends in the left-right direction and is communicated with the outside through an air inlet hole and is communicated with the exhaust fan through an air extraction hole. Compared with natural heat dissipation, the use of the pressure of the exhaust fan to form a convective heat dissipation organization can improve the heat dissipation efficiency and reduce the surface temperature of the photovoltaic panel. The electric energy and heat energy generated by the photovoltaic cover plate are supplied to users or stored through the energy conversion system, effectively utilizing environmental resources.

Description

Technical Field

[0001] The present invention belongs to the technical field of energy-saving cover plates, and particularly relates to a photovoltaic cover plate capable of recovering waste heat from power generation and an energy conversion system. Background Art

[0002] A solar photovoltaic sewage treatment tank cover plate is a building structure that combines solar photovoltaic technology with the function of a sewage treatment tank cover plate. Its purpose is to convert solar energy into electrical energy through photovoltaic panels, while meeting the covering requirements of the sewage treatment tank and preventing the escape of volatile organic compounds. In recent years, with the continuous development of solar energy technology, photovoltaic cover plates have gradually become an important distributed energy solution. However, photovoltaic sewage treatment tank cover plates face two key problems during operation: heat dissipation and waste heat recovery. These problems not only affect the power generation efficiency of the system but also relate to the energy utilization efficiency and sustainability of the entire sewage treatment facility.

[0003] The key component of a photovoltaic cover plate is the photovoltaic panel. During operation, the photovoltaic panel generates a large amount of heat, and the increase in its temperature will cause a significant decrease in the photoelectric conversion efficiency. Research shows that for silicon-based solar cells, when the operating temperature increases by 10°C, the photoelectric conversion efficiency will decrease by 3% - 5%. In addition, high temperature will accelerate the aging of the battery and reduce its service life. In the application scenario of photovoltaic cover plates, since photovoltaic panels are usually installed on the roof and are exposed to direct sunlight for a longer time, the heat dissipation problem is more prominent. Therefore, solving the heat dissipation problem of photovoltaic cover plates is crucial for improving power generation efficiency and extending the system life.

[0004] Existing photovoltaic cover plates usually set ventilation ducts on the back of the photovoltaic panel for natural heat dissipation, but the heat dissipation effect is not ideal, and the heat generated by the photovoltaic panel is not recycled, resulting in waste of heat resources. In the process of sewage treatment, the recycling of heat resources can significantly improve energy utilization efficiency, reduce operating costs, and reduce carbon emissions. Therefore, developing a photovoltaic cover plate capable of recovering waste heat from power generation and an energy conversion system is of great significance for improving the energy efficiency and sustainability of sewage treatment facilities. Summary of the Invention

[0005] The purpose of the present invention is to provide a photovoltaic cover plate capable of recovering waste heat from power generation and an energy conversion system to solve the problems in the above background art.

[0006] The present invention provides the following technical solutions.

[0007] A photovoltaic cover plate capable of recovering waste heat from power generation, comprising a cover plate unit and an exhaust fan;

[0008] The cover plate unit includes a body, a photovoltaic panel, and a sealing structure; the body extends in the left-right direction, and an installation platform is provided thereon; the photovoltaic panels are arranged at intervals in the left-right direction, and the front and rear ends thereof are respectively connected to the installation platform; the sealing structure is arranged at the left and right ends of the body, and together with the photovoltaic panel and the body, encloses a relatively closed heat collection cavity; the heat collection cavity extends in the left-right direction, communicates with the outside through an air inlet hole, and communicates with an exhaust fan through an exhaust hole;

[0009] The sealing structure includes a fixing part, a moving plate, an installation frame, a guide rail, and a pulley; the fixing part is arranged at the end of the body and blocks part of the end of the heat collection cavity, and the unblocked end of the heat collection cavity forms an air passage; the moving plate is slidably arranged at the end of the body in the front-rear direction, and completely blocks the air passage at at least one sliding position; the installation frame is arranged at the end of the body and extends in the front-rear direction; the guide rail is arranged on the installation frame and extends in the front-rear direction; the pulley is connected to the moving plate and cooperates with the guide rail.

[0010] Further, two air passages are arranged at intervals at one end of the heat collection cavity, two moving plates of the sealing structure are arranged corresponding to the air passages, and two pulleys are arranged correspondingly; when the air passages are opened, the moving plates are located between the two air passages and on the outer side of the fixing part away from the heat collection cavity; two guide rails are arranged in parallel; the pulleys are in one-to-one correspondence with the guide rails.

[0011] Further, the body is an upwardly convex arched structure, and the chord direction of the arched structure is the left-right direction; the installation platforms are arranged on the front and rear sides of the body along the arc direction of the body; the fixing part is a convex platform structure, the inner end of which extends into the heat collection cavity, and the outer end is a vertical surface.

[0012] Further, the installation frame includes a first frame and a second frame; the two ends of the first frame are respectively connected to the two installation platforms of the body, it is arranged along the arc direction of the body and is located on the convex platform structure; the second frame is connected to the first frame and is located on the outer side of the convex platform structure away from the heat collection cavity;

[0013] The moving plate and the pulley are both arranged vertically; a sealing strip is arranged in a circle along the outer edge on the side of the moving plate close to the heat collection cavity, and the sealing strip contacts the fixing part;

[0014] Further, the exhaust hole is located on the moving plate at the right end of the heat collection cavity; the air inlet hole is located on the moving plate at the left end of the heat collection cavity.

[0015] Further, a temperature sensor is arranged in the heat collection cavity, a controller is arranged on the exhaust fan, and the controller is respectively connected to the temperature sensor and the motor of the exhaust fan.

[0016] An energy conversion and utilization system of a photovoltaic cover plate that utilizes recyclable power generation waste heat, comprising a cover plate unit, an exhaust fan, an inverter, a molten salt energy storage device, and a heating device;

[0017] The molten salt energy storage device comprises a heater, a molten salt hot tank, a hot salt delivery pump, a molten salt heat exchanger, a molten salt cold tank, and a cold salt delivery pump which are sequentially connected to form a loop; the heater is connected to the exhaust fan and is connected to the inverter;

[0018] The heating device includes a first water supply tank and a heat user; the water outlet pipe of the first water supply tank is connected to the molten salt heat exchanger; the water with a temperature of T1 output by the first water supply tank exchanges heat with the molten salt in the molten salt heat exchanger to obtain hot water with a temperature of T2, which is then delivered to the heat user.

[0019] Further, a heat pump device is included, which also includes a heat pump device and an exhaust gas condenser;

[0020] The heat pump device comprises a first heat exchanger, a vapor-liquid separator, a compressor, a second heat exchanger, a liquid storage tank, a filter and an expansion valve which are sequentially connected to form a loop; the first heat exchanger is connected to the exhaust fan, and a refrigerant is arranged therein;

[0021] The tail gas condenser is connected to the heater; the first heat exchanger is connected to the tail gas condenser through the heater;

[0022] The heating device also includes a second water supply tank, a water outlet pipe of which is connected to a second heat exchanger. Water with a temperature of T3 output by the second water supply tank exchanges heat with high-temperature and high-pressure gas in the second heat exchanger to obtain hot water with a temperature of T4, which is then delivered to heat users.

[0023] Furthermore, it also includes a steam power generation device; the steam power generation device includes a steam generator, a steam turbine and an electricity user; the steam turbine is connected to the steam generator, and the electricity user is connected to the steam turbine; the steam generator is connected to the molten salt hot tank through a hot salt transfer pump.

[0024] Furthermore, an external power source is included; the heater is also connected to the expansion valve, the inverter, the heat user and the external power source.

[0025] The present invention has the following beneficial effects:

[0026] 1. A photovoltaic cover plate and an energy conversion system capable of recovering waste heat from power generation provided by the present invention. Its sealing structure, photovoltaic panel and the main body jointly enclose a relatively closed heat collection cavity. The heat collection cavity is communicated with the outside through an air inlet hole and is communicated with a suction fan through an air extraction hole. Air enters the heat collection cavity through the air inlet hole, flows to the air extraction hole under the action of the suction fan, and then enters the suction fan through the air extraction hole. Compared with natural heat dissipation, using the pressure of the suction fan to form a convective heat dissipation organization can improve the heat dissipation efficiency, reduce the surface temperature of the photovoltaic panel, reduce the risk of spontaneous combustion of the photovoltaic panel, and improve the safety of photovoltaic power generation; the air inlet hole and the air extraction hole of the heat collection cavity are located on opposite sides, so that the air can absorb the heat of the photovoltaic panel to the greatest extent before being extracted.

[0027] 2. A photovoltaic cover plate and an energy conversion system capable of recovering waste heat from power generation provided by the present invention. A temperature sensor is arranged in the heat collection cavity, and a controller is arranged on the suction fan. The controller can automatically adjust the working frequency of the suction fan according to the temperature in the heat collection cavity to achieve efficient heat dissipation.

[0028] 3. A photovoltaic cover plate and an energy conversion system capable of recovering waste heat from power generation provided by the present invention. By adjusting the position of the moving plate, the opening or closing of the air passage is realized, so as to carry out natural heat dissipation or waste heat recovery, and the moving plate will not protrude out of the cover plate unit during movement and will not interfere with other structures.

[0029] 4. A photovoltaic cover plate and an energy conversion system capable of recovering waste heat from power generation provided by the present invention. Air extraction holes and air inlet holes are opened on the moving plate, without damaging the sealing of the sewage treatment tank, effectively avoiding the escape of harmful gases.

[0030] 5. A photovoltaic cover plate and an energy conversion system capable of recovering waste heat from power generation provided by the present invention. The heat pump device and the molten salt energy storage device are combined to recover and utilize the heat generated by the photovoltaic panel, provide heating in various ways for heat users, and can store energy, effectively utilizing waste heat resources.

[0031] 6. A photovoltaic cover plate and an energy conversion system capable of recovering waste heat from power generation provided by the present invention. When the energy provided by the cover plate unit is insufficient, an external power supply is connected to heat the user to ensure the operation of the system; when the energy provided by the cover plate unit is sufficient, the molten salt energy storage device can be used for energy storage. Description of the Drawings

[0032] Figure 1 It is a schematic structural diagram of the cover plate unit related to the present invention;

[0033] Figure 2 It is for the present invention Figure 1 The sectional view at A-A in it;

[0034] Figure 3 It is a schematic structural diagram of one end of the cover plate unit related to the present invention;

[0035] Figure 4 For the present invention Figure 3 is a sectional view taken along line B-B in the present invention;

[0036] Figure 5 is a schematic diagram of the energy conversion and utilization system related to the present invention.

[0037] In the figure: 100 - cover plate unit, 110 - body, 111 - mounting table, 112 - groove, 113 - angle steel, 114 - reinforcing rib, 120 - photovoltaic panel, 130 - sealing structure, 131 - fixing part, 132 - moving plate, 133 - first frame, 134 - second frame, 135 - guide rail, 136 - pulley, 140 - heat collection chamber, 200 - exhaust fan, 300 - inverter, 400 - heat pump device, 410 - first heat exchanger, 420 - expansion valve, 430 - vapor - liquid separator, 440 - compressor, 450 - second heat exchanger, 460 - liquid storage tank, 470 - filter, 500 - molten salt energy storage device, 510 - heater, 520 - molten salt hot tank, 530 - hot salt transfer pump, 540 - molten salt heat exchanger, 550 - molten salt cold tank, 560 - cold salt transfer pump, 600 - steam power generation device, 610 - steam generator, 620 - steam turbine, 630 - electricity user, 700 - heating device, 710 - first water supply tank, 720 - second water supply tank, 730 - heat user, 800 - tail gas condenser. Detailed implementation manners

[0038] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0039] Unless otherwise defined or explained, all professional and scientific terms used herein have the same meaning as those familiar to users skilled in the art. In addition, any methods and materials similar or equivalent to the described content can be applied to the method of the present invention.

[0040] It can be understood that although terms such as "first", "second", etc. can be used herein to describe different elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. Therefore, the first element can be called the second element without departing from the teachings of the concept of the present disclosure.

[0041] Unless otherwise clearly specified and defined, the terms "connected", "communicated", and "coupled" in the present invention should be understood in a broad sense. For example, it can be a fixed connection, or can be connected through an intermediate medium, and can be the communication inside two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0042] For example, if one element (or component) is said to be on another element, coupled with or connected to another element, then the said one element can be directly formed on, coupled with or connected to the said another element, or there can be one or more intermediate elements between them. On the contrary, if the expressions "directly on...", "directly coupled with..." and "directly connected with..." are used herein, it means that there are no intermediate elements. Other words used to illustrate the relationship between elements should be interpreted similarly, such as "between..." and "directly between...", "attached" and "directly attached", "adjacent" and "directly adjacent", etc.

[0043] In addition, it should be noted that the words "front", "rear", "left", "right", "upper" and "lower" used in the following description refer to the directions in the drawings. The words "inner" and "outer" respectively refer to the directions towards or away from the geometric center of a specific component. It can be understood that here, these terms are used to describe the relationship of one element, layer or region relative to another element, layer or region as shown in the drawings. Except for the orientations described in the drawings, these terms should also include other orientations of the device.

[0044] As Figures 1-4 shown, a photovoltaic cover plate capable of recovering waste heat of power generation includes a cover plate unit 100. The cover plate unit 100 extends along the span direction of the sewage tank, and one or more groups are arranged perpendicular to the span direction of the sewage tank. For the convenience of description, in the following text, the span direction of the sewage tank is taken as the left-right direction, and the direction perpendicular to the span direction of the sewage tank is taken as the front-rear direction.

[0045] The cover plate unit 100 includes a body 110, a photovoltaic panel 120 and a sealing structure 130; the body 110 is arranged on a building structure; the photovoltaic panels 120 are arranged at intervals on the body 110 along the left-right direction; the sealing structure 130 is arranged on the body 110 and jointly encloses a relatively closed heat collection cavity 140 with the photovoltaic panels 120 and the body 110. The heat collection cavity 140 extends along the left-right direction; the heat collection cavity 140 communicates with the outside through an air inlet hole, and air enters the heat collection cavity 140 through the air inlet hole; the heat collection cavity 140 communicates with a blower 200 through an air extraction hole, and the air extraction pipe of the blower 200 penetrates through the air extraction hole to realize the communication between the blower 200 and the heat collection cavity 140.

[0046] The air inlet and the air extraction hole of the heat collection cavity 140 are located on opposite sides, enabling the air to absorb the heat of the photovoltaic panel 120 to the greatest extent before extraction. External air enters the heat collection cavity 140 through the air inlet, and under the pressure of the exhaust fan 200, it flows to the air extraction hole, and then enters the exhaust fan 200 through the exhaust pipe. The exhaust fan 200 can extract the high-temperature air in the heat collection cavity 140. Compared with natural heat dissipation, using the pressure of the exhaust fan 200 to form a convective heat dissipation organization can improve the heat dissipation efficiency, reduce the surface temperature of the photovoltaic panel 120, reduce the spontaneous combustion risk of the photovoltaic panel 120, and improve the safety of photovoltaic power generation.

[0047] In some embodiments, the body 110 is an upwardly convex arched structure, and the chord direction of the arched structure is the left-right direction. Reinforcing ribs 114 are provided at the bottom of the body 110 to enhance the structural strength of the body 110. Mounting platforms 111 are provided on the body 110, and the mounting platforms 111 are arranged on the front and rear sides of the body 110 along the arc direction of the body 110. The front and rear ends of the photovoltaic panel 120 are respectively connected to the mounting platforms 111 to realize the installation and fixation of the photovoltaic panel 120 on the body 110.

[0048] In some embodiments, grooves 112 are formed on the side walls of the mounting platforms 111 facing the photovoltaic panel 120, and the extending direction of the grooves 112 is the same as the extending direction of the arched structure. The ends of the photovoltaic panel 120 are inserted into the grooves 112. At least one end of the groove 112 is open. When installing the photovoltaic panel 120, the photovoltaic panels 120 can be pushed into the grooves 112 one by one from the openings of the grooves 112 and slid to the installation positions. Optionally, the body 110 is made of fiberglass, the mounting platforms 111 are made of fiberglass, and are integrally formed with the body 110.

[0049] The grooves 112 are located at the tops of the mounting platforms 111, facilitating the installation of the photovoltaic panel 120. Gaskets are arranged conformally in the grooves 112, and the gaskets are located below the photovoltaic panel 120 to prevent damage to the photovoltaic panel 120 during installation. Angle steels 113 are also arranged in the grooves 112. One side plate of the angle steel 113 presses on the top surface of the photovoltaic panel 120, and the other side plate is fixedly connected to the inner wall of the groove 112 to ensure the installation stability of the photovoltaic panel 120. The angle steels 113 are arranged conformally with the grooves 112, and one side plate of the angle steel 113 presses on the photovoltaic panel 120 to ensure the installation stability of the photovoltaic panel 120.

[0050] The sealing structure 130 is arranged at the left and right ends of the body 110, and together with the body 110 and the photovoltaic panel 120, forms a heat collection chamber 140 extending in the left and right directions. The sealing structure 130 includes a fixing portion 131, a movable plate 132, a mounting frame, a guide rail 135 and a pulley 136. The fixing portion 131 is arranged at the end of the body 110, and blocks part of the end of the heat collection chamber 140, and the unblocked end of the heat collection chamber 140 forms an air passage; the movable plate 132 is slidably arranged at the end of the body 110 in the front-to-back direction, so that it can completely block or completely stagger the air passage; the mounting frame is arranged at the end of the body 110 and extends in the front-to-back direction; the guide rail 135 is arranged on the mounting frame and extends in the front-to-back direction; the pulley 136 is arranged on the movable plate 132 and cooperates with the guide rail 135; the pulley 136 moves on the guide rail 135, driving the movable plate 132 to move forward and backward, so as to realize the position adjustment of the movable plate 132.

[0051] Due to the arched design of the body 110, rainwater or snow water that penetrates into the heat collection chamber 140 from the gaps of the photovoltaic panels 120 will naturally flow to the left and right ends along the bottom surface of the heat collection chamber 140, pushing the movable plate 132 to open the air channel and drain the accumulated water. This design can achieve both heat dissipation and drainage functions.

[0052] In one embodiment, the mounting frame includes a first frame 133 and a second frame 134, the two ends of the first frame 133 are respectively connected to the two mounting platforms 111 of the body 110, and the second frame 134 is connected to the first frame 133. The guide rail 135 is arranged in the second frame 134 and is a steel wire rope. A support is provided below the pulley 136, and the pulley 136 is rotatably arranged on the support. The steel wire rope is passed between the support and the pulley 136 and cooperates with the bottom of the pulley 136. The side of the movable plate 132 is connected to the support and is located on the side of the fixed part 131 away from the heat collecting chamber 140. The pulley 136 rotates along the steel wire rope and drives the movable plate 132 to move in the front and rear directions through the support.

[0053] In one embodiment, two air extraction holes are provided and located on the movable plate 132 at the right end of the heat collection chamber 140, and the exhaust fan 200 is connected to the two air extraction holes through two air extraction pipes. An electric valve is provided on the air extraction pipe to adjust the air extraction amount.

[0054] In one embodiment, two air inlet holes are provided and located on the movable plate 132 at the left end of the heat collection chamber 140. A one-way air inlet valve is installed on the air inlet hole to achieve one-way flow of air in the heat collection chamber 140.

[0055] Providing the air extraction holes and the air inlet holes on the movable plate 132 can ensure the integrity of the cover plate unit 100 and prevent the gas in the sewage pool from escaping to the outside.

[0056] In one embodiment, two air channels are spaced apart at one end of the heat collection chamber 140. Two movable plates 132 are arranged at one end of the heat collection chamber 140 corresponding to the air channels, and two pulleys 136 are arranged at one end of the heat collection chamber 140 corresponding to the air channels. When the air channels are opened, the two movable plates 132 are located between the two air channels. When the two movable plates 132 move from the positions between the two air channels to the directions of the two air channels respectively, the minimum value of their movement distance satisfies that the two air channels are completely closed; the two movable plates 132 move from the air channels to the directions between the two air channels respectively, and the minimum value of their movement distance satisfies that the two air channels are completely opened. The movement range of the movable plate 132 can also just satisfy that the movable plate 132 completely blocks or completely staggers the air channels.

[0057] In order to optimize the structural space, the second frame 134 is located between the two air channels, two guide rails 135 are arranged in parallel, and the pulley 136 corresponds to the guide rail 135 one by one, thereby reducing the required length of the guide rail 135 and the second frame 134, and the area of the fixed portion 131 between the two air channels is larger than the area of a single movable plate 132, so that the movable plate 132 can be completely located in the area where the fixed portion 131 is located, thereby realizing the full opening of the air channel.

[0058] The cross section of the air passage is an inverted isosceles trapezoid.

[0059] In some embodiments, the fixing portion 131 is a boss structure, the inner end of which extends to the inside of the heat collection chamber, and the outer end is a vertical surface. The boss structure is consistent with the extension direction of the main body. Preferably, the fixing portion 131, the mounting platform 111 and the main body 110 are integrally arranged. The end of the first frame 133 is installed in the groove 112 of the mounting platform 111 and is connected to the angle steel 113 by bolts. The first frame 133 is arranged in the arc direction of the main body 110 and is located above the boss structure. The second frame 134 is located on the outside of the fixing portion 131 away from the heat collection chamber 140. The pulley 136 and the movable plate 132 are both arranged vertically. A circle of sealing strips is arranged along the outer edge of the movable plate 132 close to the heat collection chamber 140. The sealing strip is in contact with the fixing portion 131 to improve the sealing of the heat collection chamber 140, thereby effectively collecting the high-temperature air inside the collector. The sealing strip can be made of PVC or rubber.

[0060] On the one hand, the first frame 133 provides an installation position for the second frame 134, and on the other hand, the first frame 133 can close the end of the groove 112 to prevent the photovoltaic panel 120 from sliding out of the end of the groove 112. The first frame 133 and the second frame 134 are both made of glass fiber reinforced plastic.

[0061] The photovoltaic panel 120 is a rigid photovoltaic panel 120, which uses crystalline silicon cells, is safe and reliable, and has a relatively high photoelectric conversion efficiency. The single photovoltaic panel 120 has a thickness of about 30 mm. Each panel is provided with a positive connection line and a negative connection line. The solar absorption surface of the photovoltaic panel 120 faces upward, and the back surface with the positive and negative connection lines installed faces downward.

[0062] Optionally, all the photovoltaic panels 120 of the cover unit 100 are connected in series. The positive connection line of the photovoltaic panel 120 is connected to the negative connection line of the adjacent photovoltaic panel 120 to form a battery pack, and the battery pack is connected to the inverter 300.

[0063] Optionally, the height of the heat collection cavity 140 is not less than 10 cm, which effectively dissipates the heat on the back surface of the photovoltaic panel 120 and reduces the heat loss.

[0064] In some embodiments, a temperature sensor is provided in the heat collection cavity 140, and a controller is provided on the exhaust fan 200 for controlling the frequency of the exhaust fan 200. The controller is respectively connected to the temperature sensor and the motor of the exhaust fan 200. When the temperature collected by the temperature sensor is within the normal temperature range, the fan operates at a frequency f1; when the temperature collected by the temperature sensor is higher than the maximum temperature, for every 10 °C increase in temperature, the fan frequency increases by 2 Hz on the basis of f1; when the temperature collected by the temperature sensor is lower than the minimum temperature, the exhaust fan 200 stops working. At this time, the moving plate 132 can be pushed to open the air passage for heat dissipation. The normal temperature range, the maximum temperature and the minimum temperature can be designed as needed. The normal temperature range can be 30 - 70 °C, the minimum temperature can be 30 °C, and the maximum temperature can be 70 °C.

[0065] On the other hand, the present invention provides an energy conversion system for a photovoltaic cover plate that utilizes recoverable waste heat from power generation, as Figure 5 shown, including a cover unit 100, an exhaust fan 200, an inverter 300, a heat pump device 400, a molten salt energy storage device 500, a steam power generation device 600, a heating device 700, and a tail gas condenser 800.

[0066] In some embodiments, the heat pump device 400 is communicated with the exhaust fan 200 and includes a first heat exchanger 410, a vapor-liquid separator 430, a compressor 440, a second heat exchanger 450, a liquid storage tank 460, a filter 470, and an expansion valve 420. The first heat exchanger 410, the vapor-liquid separator 430, the compressor 440, the second heat exchanger 450, the liquid storage tank 460, the filter 470, and the expansion valve 420 are sequentially communicated through pipelines to form a loop.

[0067] The first heat exchanger 410 is connected to the exhaust fan 200, and a refrigerant is provided therein. The hot air generated by the photovoltaic panel 120 is transported by the exhaust fan 200 to the first heat exchanger 410, where the hot air exchanges heat with the refrigerant; after absorbing the heat in the hot air, the refrigerant becomes a high-temperature and low-pressure vapor-liquid mixture, which enters the vapor-liquid separator 430 and undergoes gas-liquid separation therein to obtain high-temperature and low-pressure gas. The high-temperature and low-pressure gas enters the compressor 440 and is heated and pressurized to become high-temperature and high-pressure gas. The high-temperature and high-pressure gas releases heat energy in the second heat exchanger 450 and is converted into a low-temperature and high-pressure vapor-liquid mixture. The liquid of the low-temperature and high-pressure vapor-liquid mixture is stored in the liquid storage tank 460, and the gas of the low-temperature and high-pressure vapor-liquid mixture sequentially passes through the filter 470 and the expansion valve 420 to be converted into low-temperature and low-pressure gas. The low-temperature and low-pressure gas enters the first heat exchanger 410 and exchanges heat with the hot air from the exhaust fan 200 to carry out the next heat pump cycle.

[0068] The refrigerant is low-temperature and low-pressure gas. The compressor 440 is an energy-consuming device.

[0069] In some embodiments, the molten salt energy storage device 500 includes a heater 510, a molten salt hot tank 520, a hot salt transfer pump 530, a molten salt heat exchanger 540, a molten salt cold tank 550, and a cold salt transfer pump 560. The heater 510, the molten salt hot tank 520, the hot salt transfer pump 530, the molten salt heat exchanger 540, the molten salt heat exchanger 540, and the cold salt transfer pump 560 are sequentially connected to form a loop. The molten salt hot tank 520 is connected to the steam power generation device 600.

[0070] The heater 510 is connected to the exhaust fan 200, uses the hot air to heat the molten salt, and stores the heated molten salt in the molten salt hot tank 520. The molten salt in the molten salt hot tank 520 can be directly input to the steam power generation device 600 for power generation, or can enter the molten salt heat exchanger 540 to supply the heating device 700; the heat-exchanged low-temperature molten salt is stored in the molten salt cold tank 550 and is transported to the heater 510 by the cold salt transfer pump 560 to carry out the next molten salt energy storage cycle.

[0071] The heater 510 is connected to the expansion valve 420 of the heat pump device 400. When there is residual heat in the low-temperature and low-pressure gas output by the expansion valve 420, it is used to heat the low-temperature molten salt.

[0072] The heater 510 is also connected to the inverter 300 and an external power source, uses electrical energy to heat the molten salt, and stores the heated molten salt in the molten salt hot tank 520. The electricity generated by the photovoltaic panel 120 is transported to the heater 510 through the inverter 300.

[0073] The molten salt can be Hitec salt, with a melting point lower than 240 °C, reducing the risk of molten salt solidification.

[0074] In some embodiments, the steam power generation device 600 includes a steam generator 610, a steam turbine 620, and an electricity consumer 630. The steam turbine 620 is in communication with the steam generator 610, and the electricity consumer is connected to the steam turbine 620. The heat source of the steam generator 610 is the high-temperature molten salt output from the molten salt hot tank 520. The high-temperature molten salt generates a large amount of steam in the steam generator 610, and the steam drives the steam turbine 620 to generate electricity. The generated electric energy is transmitted to the electricity consumer 630 to achieve the energy conversion of "heat-heat-electricity".

[0075] In some embodiments, the heating device 700 includes a first water supply tank 710, a second water supply tank 720, and a heat consumer 730. The outlet pipe of the first water supply tank 710 is in communication with the molten salt heat exchanger 540. The water with a temperature of T1 output from the first water supply tank 710 exchanges heat with the molten salt in the molten salt heat exchanger 540 to obtain hot water with a temperature of T2, and is then delivered to the heat consumer 730. The outlet pipe of the second water supply tank 720 is in communication with the second heat exchanger 450. The water with a temperature of T3 output from the second water supply tank 720 exchanges heat with the high-temperature and high-pressure gas in the second heat exchanger 450 to obtain hot water with a temperature of T4, and is then delivered to the heat consumer 730.

[0076] When the sum of the amount of hot water with a temperature of T2 and the amount of hot water with a temperature of T4 is greater than the demand of the heat consumer 730, the excess hot water can be delivered to the heater 510 for heating the low-temperature molten salt.

[0077] In some embodiments, the tail gas condenser 800 is in communication with the heater 510. After the hot air in the heater 510 exchanges heat, it is cooled to a temperature that can be discharged into the atmosphere through the tail gas condenser 800 and then discharged into the atmosphere. The tail gas condenser 800 is in communication with the first heat exchanger 410 through the heater 510. After the hot air in the first heat exchanger 410 exchanges heat, it enters the tail gas condenser 800 through the non-operating heater 510 for cooling and then is discharged into the atmosphere.

[0078] Generally speaking, there are five sources of the high-temperature heat source of the heater 510: one is the high-temperature waste heat transported by the induced draft fan 200; the second is the low-temperature waste heat of the low-temperature and low-pressure gas in the expansion valve 420 of the heat pump device 400, that is, the high-temperature waste heat transported by the induced draft fan 200 becomes lower-temperature waste heat after heat exchange and cooling in the second heat exchanger 450; the third is the photovoltaic alternating current passing through the inverter 300, and the photovoltaic power drives heating; the fourth is the surplus hot water of the heating device 700; the fifth is an external power source. When the sum of the first four sources is not sufficient to supply the heater 510, the external power source is started to drive heating.

[0079] To further illustrate the solution of the present application, taking one day as a cycle, the energy conversion process of the energy conversion system in one cycle is briefly described. The energy obtained through photovoltaic power generation during the day is denoted as G 光; The waste heat energy collected from the heat collection cavity 140 is denoted as G 热 ; The energy required by the daytime heat user 730 is denoted as G 暖day ; The energy required by the nighttime heat user 730 is denoted as G 暖night ; The loss coefficient of the molten salt energy storage device 500 during day-night conversion is ɵ.

[0080] Example 1 G 热 ≥G 暖day

[0081] When G 热 ≥G 暖day , it indicates that the waste heat energy of daytime photovoltaic power generation is sufficient to supply the daytime heat user. The hot air collected during the day is pumped by the exhaust fan 200 to the heater 510, where the hot air heats the cold molten salt to a certain temperature and then sends it to the molten salt hot tank 520. It is transported to the molten salt heat exchanger 540 through the hot salt transfer pump 530. The tap water with a temperature of T1 from the first water supply tank 710 exchanges heat with the hot molten salt in the molten salt heat exchanger 540 and becomes hot water with a temperature of T2, which is supplied to the heat user 730; at this time, there is still (G 热 -G 暖day ) energy surplus during the day, and the surplus energy (G 热 -G 暖day ) is stored in the molten salt hot tank 520.

[0082] At the same time, the daytime photovoltaic power generation amount G 光 is transported to the heater 510 and is all used to heat the cold molten salt, which is also stored in the molten salt hot tank 520.

[0083] At this time, the energy conversion system can not only achieve autonomous energy supply during the day, but also the total surplus energy during the day (G 热 -G 暖day +G 光 ).

[0084] Example 2

[0085] On the basis of Example 1, when ɵ (G 热 -G 暖day +G 光 ) < G 暖night , it indicates that the total surplus energy during the day in Example 1 is not sufficient to supply the nighttime heat user. Then, at this time, power needs to be taken from an external power source [G 暖night - ɵ (G 热 -G 暖day +G 光 ).

[0086] At this time, there is an energy gap in the energy conversion system during this cycle [G 暖night -ɵ (G 热 -G 暖day +G光 )].

[0087] Example 3

[0088] Based on Example 1, when ɵ(G 光 +G 热 -G 暖day ) = G 暖night , it indicates that the total daytime surplus energy in Example 1 can exactly supply power to the nighttime heat users, and at this time, the all-day energy balance of the energy conversion system is achieved.

[0089] Example 4

[0090] Based on Example 1, when ɵ(G 光 +G 热 -G 暖day ) > G 暖night , it indicates that there is a surplus in the daytime heat generation, which can not only supply the daytime heat users, and the remaining amount, together with the daytime photovoltaic power generation, still has a surplus after supplying the nighttime heat users. At this time, the overall surplus energy ɵ(G 光 +G 热 -G 暖day ) - G 暖night is sent to the steam power generation device 600 for power generation. At this time, the energy conversion system can achieve autonomous energy supply, and the production capacity ɵ(G 光 +G 热 -G 暖day ) - G 暖night .

[0091] Example 5 G 热 <G 暖day

[0092] When G 热 <G 暖day , it indicates that the daytime waste heat energy is not enough to supply the daytime heat users, so the daytime photovoltaic power generation needs to supply energy to the daytime heat users at the same time.

[0093] At this time, the hot air collected during the day is pumped to the heater 510 by the exhaust fan 200, and the energy obtained from the photovoltaic power generation is also sent to the heater 510 through the inverter 300. Here, the cold molten salt is heated to a certain temperature and then sent to the molten salt hot tank 520, and then all or part of the high-temperature molten salt is transported to the molten salt heat exchanger 540 by the hot salt transfer pump 530. The tap water with a temperature of T1 from the first water supply tank 710 exchanges heat with the hot molten salt in the molten salt heat exchanger 540 and becomes hot water with a temperature of T2, which is supplied to the heat user 730.

[0094] Example 6

[0095] Based on Example 5, during the day, when G 光 +G 热 <G暖day When it is necessary to obtain power from an external power source (G 暖day -G 光 -G 热 ), and all the electricity used by heat users at night is obtained from an external power source.

[0096] At this time, the energy conversion system has insufficient production capacity, consumes energy both during the day and at night, and the total energy consumption is (G 暖day -G 光 -G 热 +G 暖night ).

[0097] Example 7

[0098] Based on Example 5, during the day, when G 光 +G 热 =G 暖day it indicates that the combined photovoltaic power generation and waste heat recovery during the day are just balanced with the heat user load during the day, and the system energy reaches balance during the day.

[0099] At night, all the electricity used by heat users is obtained from an external power source.

[0100] At this time, the energy of the energy conversion system reaches balance during the day, and the energy consumption at night is G 暖night .

[0101] Example 8

[0102] Based on Example 5, during the day, when G 光 +G 热 >G 暖day it indicates that after the waste heat recovery energy and photovoltaic power generation energy are supplied to the heat users during the day, there is still surplus. Then the total surplus energy during the day is (G 光 +G 热 -G 暖day ) and is stored in the molten salt thermal storage tank 520.

[0103] At this time, energy can be self-supplied during the day.

[0104] Example 9

[0105] Based on Example 8, at night, when ɵ(G 光 +G 热 -G 暖day ) < G 暖night it indicates that the total surplus energy during the day is not enough to supply the heat users at night. At this time, it is necessary to obtain power from an external power source [G 暖night - ɵ(G 光 +G 热 -G 暖day ).

[0106] At this time, the energy conversion system has insufficient production capacity, and the energy consumption at night is [G暖night -ɵ(G 光 +G 热 -G 暖day )。

[0107] Example 10

[0108] Based on Example 8, at night, when ɵ(G 光 +G 热 -G 暖day ) = G 暖night , the total daytime surplus energy is just enough to supply the night-time heat users, and the overall energy balance of the system is achieved at this time.

[0109] Example 11

[0110] Based on Example 8, at night, when ɵ(G 光 +G 热 -G 暖day ) > G 暖night , the total daytime surplus energy is sufficient to supply the night-time heat users, and there is still a surplus of [ɵ(G 光 +G 热 -G 暖day ) - G 暖night . At this time, the surplus energy [ɵ(G 光 +G 热 -G 暖day ) - G 暖night is sent to the steam power generation device 600 for power generation.

[0111] At this time, the system can achieve autonomous energy supply, and the energy production is [ɵ(G 光 +G 热 -G 暖day ) - G 暖night .

[0112] Example 12

[0113] In order to reduce the loss of the molten salt energy storage device 500, the waste heat energy can also be heat-exchanged with the water from the second water supply tank 720 in the second heat exchanger 450 through the heat pump device 400 to achieve the purpose of providing energy to the heat user 730.

[0114] When G 热 ≥ G 暖day , and ɵ(G 光 +G 热 -G 暖day ) = G 暖night , assuming G 热 = G 热1 +G 热2 , G 热1 = G 暖day , ɵ(G热2 +G 光 ) = G 暖night , where G 热1 represents the energy supplied to the daytime heat users by the molten salt energy storage device 500, G 热2 represents the surplus waste heat energy during the day, G 热2 combined with photovoltaic power generation G 光 is stored and supplies power to the nighttime heat users. At this time, the energy balance of the system can be achieved.

[0115] If the energy supply to the daytime heat users is directly provided by the heat pump device 400, assuming G 热 = G 热1 ’ + G 热2 ’, G 热1 ’ is the energy supplied by the heat pump device 400 to heat the daytime heat users, G 热2 ’ represents the surplus waste heat energy during the day, G 热2 combined with photovoltaic power generation G 光 is stored and supplies power to the nighttime heat users.

[0116] Since the loss of the heat pump device 400 is lower than that of the molten salt energy storage device 500, it can be known that G 热1 ’ < G 热1 ; in addition, since whether the heat pump device 400 or the molten salt energy storage device 500 is used, G 热 remains unchanged, it can be known that G 热2 ’ > G 热2 ; since ɵ(G 热2 + G 光 ) = G 暖night , it can be known that ɵ(G 热2 ’ + G 光 ) > G 暖night , that is, at this time, after the daytime photovoltaic waste heat supplies the daytime heat users, the surplus waste heat energy combined with the photovoltaic power generation amount can supply the nighttime heat users, and there is still a surplus [ɵ(G 热2 ’ + G 光 ) - G 暖night , and this surplus energy can be sent to the steam power generation device 600 for power generation.

[0117] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A photovoltaic cover plate capable of recovering waste heat for power generation, characterized in that, It includes a cover plate unit (100) and an exhaust fan (200); The cover plate unit (100) includes a body (110), a photovoltaic panel (120) and a sealing structure (130); the body (110) extends in the left - right direction, and an installation platform (111) is provided thereon; the photovoltaic panels (120) are arranged at intervals in the left - right direction, and the front and rear ends thereof are respectively connected to the installation platform (111); the sealing structure (130) is arranged at the left and right ends of the body (110), and together with the photovoltaic panel (120) and the body (110), encloses a relatively closed heat - collecting cavity (140); the heat - collecting cavity (140) extends in the left - right direction, communicates with the outside through an air inlet hole, and communicates with the exhaust fan (200) through an air extraction hole, and the air inlet hole and the air extraction hole are located on opposite sides of the heat - collecting cavity (140); The sealing structure (130) includes a fixing part (131), a moving plate (132), a mounting frame, a guide rail (135) and a pulley (136); the fixing part (131) is arranged at the end of the body (110) and blocks part of the end of the heat - collecting cavity (140), and the unblocked end of the heat - collecting cavity (140) forms an air passage; the moving plate (132) is slidably arranged at the end of the body (110) in the front - rear direction, and completely blocks the air passage in at least one sliding position; the mounting frame is arranged at the end of the body (110) and extends in the front - rear direction; the guide rail (135) is arranged on the mounting frame and extends in the front - rear direction; the pulley (136) is connected to the moving plate (132) and cooperates with the guide rail (135).

2. The photovoltaic cover plate capable of recycling waste heat of power generation according to claim 1, wherein Two air passages are arranged at intervals at one end of the heat - collecting cavity (140), two moving plates (132) of the sealing structure (130) are arranged corresponding to the air passages, and two pulleys (136) are arranged correspondingly; when the air passages are open, the moving plate (132) is located between the two air passages and on the outer side of the fixing part (131) away from the heat - collecting cavity (140); two guide rails (135) are arranged in parallel; the pulleys (136) cooperate with the guide rails (135) one - to - one.

3. A photovoltaic cover plate capable of recovering waste heat for power generation according to claim 1, characterized in that, The body (110) is an upward - convex arched structure, and the chord direction of the arched structure is the left - right direction; the installation platform (111) is arranged on the front and rear sides of the body (110) along the arc direction of the body (110); the fixing part (131) is a convex - platform structure, its inner end extends into the heat - collecting cavity, and the outer end is a vertical surface.

4. A photovoltaic cover plate capable of recovering waste heat for power generation according to claim 3, characterized in that, The mounting frame includes a first frame (133) and a second frame (134); the two ends of the first frame (133) are respectively connected to the two installation platforms (111) of the body (110), it is arranged along the arc direction of the body (110) and is located on the convex - platform structure; the second frame (134) is connected to the first frame (133), and it is located on the outer side of the convex - platform structure away from the heat - collecting cavity (140); The moving plate (132) and the pulley (136) are both vertically arranged; on one side of the moving plate (132) close to the heat collection chamber (140), a sealing strip is arranged along its outer edge, and the sealing strip contacts the fixing part (131).

5. A photovoltaic cover plate capable of recovering waste heat for power generation according to claim 1, characterized in that, The air extraction hole is located on the moving plate (132) at the right end of the heat collection chamber (140); the air inlet hole is located on the moving plate (132) at the left end of the heat collection chamber (140).

6. The photovoltaic cover plate capable of recovering waste heat for power generation according to claim 1, characterized in that A temperature sensor is arranged in the heat collection chamber (140), a controller is arranged on the exhaust fan (200), and the controller is respectively connected to the temperature sensor and the motor of the exhaust fan (200).

7. An energy conversion system for a photovoltaic cover plate capable of recovering waste heat for power generation according to any one of claims 1-6, characterized in that, It includes a cover plate unit (100), an exhaust fan (200), an inverter (300), a molten salt energy storage device (500) and a heating device (700); The molten salt energy storage device (500) includes a heater (510), a molten salt hot tank (520), a hot salt transfer pump (530), a molten salt heat exchanger (540), a molten salt cold tank (550) and a cold salt transfer pump (560) that are sequentially connected to form a loop; the heater (510) is communicated with the exhaust fan (200) and is connected to the inverter (300); The heating device (700) includes a first water supply tank (710) and a heat user (730); the water outlet pipe of the first water supply tank (710) is communicated with the molten salt heat exchanger (540); the water with a temperature of T1 output by the first water supply tank (710) exchanges heat with molten salt in the molten salt heat exchanger (540) to obtain hot water with a temperature of T2, and is transported to the heat user (730).

8. The energy conversion system according to claim 7, wherein, It also includes a heat pump device (400) and an exhaust gas condenser (800); The heat pump device (400) includes a first heat exchanger (410), a gas-liquid separator (430), a compressor (440), a second heat exchanger (450), a liquid storage tank (460), a filter (470) and an expansion valve (420) that are sequentially connected to form a loop; the first heat exchanger (410) is communicated with the exhaust fan (200), and a refrigerant is arranged therein; The exhaust gas condenser (800) is communicated with the heater (510), and the first heat exchanger (410) is communicated with the exhaust gas condenser (800) through the heater (510); The heating device (700) also includes a second water supply tank (720), the water outlet pipe of the second water supply tank (720) is communicated with the second heat exchanger (450), and the water with a temperature of T3 output by the second water supply tank (720) exchanges heat with high-temperature and high-pressure gas in the second heat exchanger (450) to obtain hot water with a temperature of T4, and is transported to the heat user (730).

9. The energy conversion system according to claim 7, characterized in that It also includes a steam power generation device (600); the steam power generation device (600) includes a steam generator (610), a steam turbine (620) and an electricity user (630); the steam turbine (620) is communicated with the steam generator (610), and the electricity user (630) is connected to the steam turbine (620); the steam generator (610) is communicated with the molten salt hot tank (520) through the hot salt transfer pump (530).

10. The energy conversion system according to claim 8, wherein, It also includes an external power supply; the heater (510) is also connected to an expansion valve (420), an inverter (300), a heat user (730), and the external power supply.

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