PVT system based on Fresnel lens

Abstract

The utility model discloses a PVT system based on a Fresnel lens, which comprises the Fresnel lens, an evacuated collector tube and a photovoltaic assembly which are sequentially arranged at intervals, the Fresnel lens is used for focusing sunlight on the evacuated collector tube to heat water in the evacuated collector tube, and the photovoltaic assembly is used for obtaining and storing solar energy; the water outlet end of the vacuum heat collecting pipe is connected to the water inlet end of the solar water tank through a pipeline, and the water inlet end of the vacuum heat collecting pipe is connected to the water outlet end of the solar water tank through a pipeline and used for circularly heating stored water in the solar water tank through solar energy. The water outlet end of the vacuum heat collecting pipe is connected to the water inlet end of an air source heat pump through a pipeline, the water outlet end of the air source heat pump is connected to a heat pump water tank, and the water outlet end of the heat pump water tank is connected to the water inlet end of the air heat pump and used for circularly heating water stored in the heat pump water tank through the air source heat pump. And the air source heat pump supplies power through the photovoltaic module.

Description

Technical Field

[0001] The utility model relates to the technical field of solar water heating systems, in particular to a PVT system based on Fresnel lenses. Background Art

[0002] PVT system (Photovoltaic Thermal Hybrid Solar System), also known as photovoltaic thermal hybrid solar system, is a solar energy utilization system that generates both electrical energy and thermal energy. This system combines photovoltaic (PV) technology and solar thermal utilization (Thermal) technology to make the utilization of solar energy more efficient.

[0003] The traditional PVT system uses sunlight to directly illuminate the collector tube to heat water. Its hot water production is closely related to the light conditions. When the light conditions are weak in the morning and evening, the hot water outlet temperature is low and cannot meet the requirements of use. Electric heating or air source heat pump supplementary heating is required, which results in a certain amount of energy waste.

[0004] Furthermore, traditional PVT systems usually use a single water tank, and heat energy is directly exchanged inside the water tank through a heat exchanger. However, during long-term operation, the heat exchanger may become scaled due to water quality problems (such as hard water), which will reduce heat exchange efficiency and increase maintenance costs. In addition, during the heat exchange process, maintaining a stable output temperature is a problem. If the temperature is not properly controlled, it may lead to unstable hot water supply and affect the user experience. Utility Model Content

[0005] The purpose of the utility model is to overcome the deficiencies of the prior art and provide a PVT system based on Fresnel lenses, which can solve the above technical problems.

[0006] The utility model provides a PVT system based on Fresnel lens, comprising:

[0007] A Fresnel lens, a vacuum heat collecting tube, and a photovoltaic module are arranged in sequence and spaced apart from each other. The Fresnel lens is used to focus sunlight on the vacuum heat collecting tube to heat water in the vacuum heat collecting tube. The photovoltaic module is used to obtain and store solar energy.

[0008] The water outlet of the vacuum heat collecting tube is connected to the water inlet of the solar water tank through a pipeline, and the water inlet of the vacuum heat collecting tube is connected to the water outlet of the solar water tank through a pipeline, so as to heat the water stored in the solar water tank by using solar energy circulation;

[0009] The water outlet end of the vacuum heat collecting tube is connected to the water inlet end of the air source heat pump through a pipeline, the water outlet end of the air source heat pump is connected to the heat pump water tank, and the water outlet end of the heat pump water tank is connected to the water inlet end of the air source heat pump, so as to use the air source heat pump to circulate and heat the water stored in the heat pump water tank, and the air source heat pump is powered by the photovoltaic module.

[0010] Furthermore, the distance between the Fresnel lens and the vacuum collector tube is set to 0.3-0.7 m.

[0011] Further, the photovoltaic assembly includes a photovoltaic panel, an inverter, and an energy storage system connected in sequence;

[0012] The photovoltaic panel is used to collect solar energy;

[0013] The inverter is used to convert and adjust the direct current obtained by the photovoltaic panel into alternating current;

[0014] The energy storage system is used to store the electric energy obtained by the photovoltaic panel and converted and adjusted by the inverter.

[0015] Furthermore, a first solenoid valve is provided at the water inlet end of the solar water tank, and a second solenoid valve is provided at the water inlet end of the air source heat pump;

[0016] A temperature sensing control unit is provided at the water outlet end of the vacuum heat collecting tube for obtaining the water outlet temperature of the vacuum heat collecting tube. The temperature sensing control unit is respectively connected to the control end of the first solenoid valve and the control end of the second solenoid valve for closing the first solenoid valve and opening the second solenoid valve when the water outlet temperature of the water outlet end of the vacuum heat collecting tube is lower than a first temperature threshold.

[0017] Furthermore, the first temperature threshold is 30°C.

[0018] Furthermore, a first water pump group is provided at the water outlet of the solar water tank, which is used to control the water flow direction of the water outlet of the solar water tank;

[0019] A second water pump group is provided at the water outlet of the heat pump water tank, which is used to control the water flow direction of the water outlet of the heat pump water tank;

[0020] The first water pump group and the second water pump group are powered by the photovoltaic assembly.

[0021] Furthermore, a return pipe is connected between the first water pump group and the water outlet of the solar water tank for recovering and circulating unused water at the user end.

[0022] Furthermore, the first water pump group and the second water pump group respectively include two water pumps for backup in case of water pump group failure.

[0023] Furthermore, the cold water inlet end of the solar water tank and the cold water inlet end of the heat pump water tank are respectively connected to cold water supply pipes; the cold water inlet end of the solar water tank is provided with a third solenoid valve, and the cold water inlet end of the heat pump water tank is provided with a fourth solenoid valve; the control ends of the third solenoid valve and the fourth solenoid valve are respectively remotely connected to the host computer, for remotely controlling the opening and closing of the third solenoid valve and the fourth solenoid valve according to time or weather conditions.

[0024] Furthermore, the water supply end of the heat pump water tank is connected to a water supply pipe for providing hot water to users.

[0025] The utility model has the following advantages:

[0026] First, by using Fresnel lens to focus sunlight onto the vacuum collector tube, Fresnel lens has a focusing function similar to convex lens, and the focusing efficiency is 30% higher than that of convex lens. The focus after focusing can make the vacuum collector tube produce higher water temperature and delay the effective hours of light. It greatly improves the utilization rate of solar energy on the vacuum collector tube. In addition, adding photovoltaic panels behind the Fresnel lens can realize the functions of producing hot water and generating electricity at the same time.

[0027] Secondly, by setting up double water tanks, the solar water tank circulates and stores water heated by solar energy, and the heat pump water tank circulates and stores water heated by air source heat pump, to ensure the stability of user water use. There is no need to use a heat exchanger to exchange heat and cold in the same water tank. At the same time, a temperature sensor control unit is provided at the water outlet of the vacuum collector to detect the outlet water temperature of the vacuum collector. Only when the outlet water temperature is lower than a certain temperature, the air source heat pump is used for heating to ensure the stability of the user's water temperature. The air source heat pump is powered by photovoltaic modules to further save energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0029] Figure 1 It is a system module diagram in the embodiment.

[0030] Figure 2 It is a schematic diagram of the positions of the Fresnel lens, the vacuum collector tube, and the photovoltaic module in the embodiment.

[0031] Figure 3 is a diagram of solar radiation intensity in an embodiment. DETAILED DESCRIPTION

[0032] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It is particularly noted that the following embodiments are only used to illustrate the present invention, but do not limit the scope of the present invention. Similarly, the following embodiments are only partial embodiments of the present invention rather than all embodiments. All other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] like Figure 1 As shown, this solution provides a PVT system based on Fresnel lens, including:

[0034] A Fresnel lens, a vacuum heat collecting tube, and a photovoltaic module are arranged in sequence and spaced apart from each other. The Fresnel lens is used to focus sunlight on the vacuum heat collecting tube to heat water in the vacuum heat collecting tube. The photovoltaic module is used to obtain and store solar energy.

[0035] The water outlet of the vacuum heat collecting tube is connected to the water inlet of the solar water tank through a pipeline, and the water inlet of the vacuum heat collecting tube is connected to the water outlet of the solar water tank through a pipeline, so as to heat the water stored in the solar water tank by using solar energy circulation;

[0036] Furthermore, the distance between the Fresnel lens and the vacuum collector tube is set to 0.3-0.7 m.

[0037] Further, the photovoltaic assembly includes a photovoltaic panel, an inverter, and an energy storage system connected in sequence;

[0038] The photovoltaic panel is used to collect solar energy;

[0039] The inverter is used to convert and adjust the direct current obtained by the photovoltaic panel into alternating current;

[0040] The energy storage system is used to store the electric energy obtained by the photovoltaic panel and converted and adjusted by the inverter.

[0041] In this embodiment, if Figure 2As shown, by using Fresnel lens to focus sunlight onto vacuum heat-collecting tube, in order to ensure the light focusing effect, since vacuum heat-collecting tube mainly uses infrared light in visible light for heating, the focus distance of light with longer wavelength (such as infrared light) behind the lens is farther from the lens than that of light with shorter wavelength (such as visible light), therefore, the distance between Fresnel lens and vacuum heat-collecting tube is set to 0.3-0.7m, so that the infrared light focal point is focused on vacuum heat-collecting tube. The vacuum heat-collecting tube is set between Fresnel lens and photovoltaic panel in photovoltaic module. While vacuum heat-collecting tube collects heat, it can also obtain light energy through photovoltaic panel, and then convert light energy into electric energy and store it in energy storage system in photovoltaic module (specifically, energy storage system can be a battery or several batteries) for power supply of other devices.

[0042] The following table compares the traditional PVT system and the Fresnel lens PVT system:

[0043]

[0044] As can be seen from the above table, the heating rate of traditional solar thermal collection systems is slow, especially in the evening when the intensity of solar radiation weakens. The heating rate per unit time is only 0.0025℃ / s. Theoretically, the temperature rises by only 9℃ in 1 hour, which is far from meeting the water demand. In contrast, the Fresnel lens hot water system can theoretically heat the water to 60℃ within 1 minute. The heating effect is much higher than that of traditional solar thermal collection systems, greatly extending the available time of solar energy. The above data is calculated based on visible light data. Since the collector tube of this patent is installed at the infrared light focusing point with higher radiation intensity, the heat collection efficiency will be higher than that of traditional PVT systems.

[0045] However, the intensity of sunlight radiation is greatly related to the environment, time, and region. Figure 3 As shown in the figure, taking the solar radiation intensity in Xiamen on January 1 as an example, the highest intensity is 270W / m2 at 13:00 noon, and drops to 0 before 7:00 and after 18:00. Therefore, air source heat pumps are needed for heating in other time periods or on cloudy days to ensure the supply of hot water for users.

[0046] The water outlet end of the vacuum heat collecting tube is connected to the water inlet end of the air source heat pump through a pipeline, the water outlet end of the air source heat pump is connected to the heat pump water tank, and the water outlet end of the heat pump water tank is connected to the water inlet end of the air source heat pump, so as to use the air source heat pump to circulate and heat the water stored in the heat pump water tank, and the air source heat pump is powered by the photovoltaic module.

[0047] In this embodiment, water heated by the air source heat pump is stored in a heat pump water tank, and water is directly supplied to users through the heat pump water tank, thereby ensuring the stability of hot water supply. At the same time, the air source heat pump is powered by photovoltaic components, and the air source heat pump and its water inlet are only started when there is not enough solar energy, thereby ensuring energy saving of the entire system.

[0048] Specifically, a first solenoid valve is provided at the water inlet end of the solar water tank, and a second solenoid valve is provided at the water inlet end of the air source heat pump;

[0049] A temperature sensing control unit is provided at the water outlet end of the vacuum heat collecting tube for obtaining the water outlet temperature of the vacuum heat collecting tube. The temperature sensing control unit is respectively connected to the control end of the first solenoid valve and the control end of the second solenoid valve for closing the first solenoid valve and opening the second solenoid valve when the water outlet temperature of the water outlet end of the vacuum heat collecting tube is lower than a first temperature threshold.

[0050] Furthermore, the first temperature threshold is 30°C.

[0051] In this embodiment, a temperature sensing control unit is provided at the water outlet of the vacuum heat collecting tube, and the temperature sensing control unit detects the water outlet temperature of the vacuum heat collecting tube. If the water outlet temperature of the vacuum heat collecting tube is lower than 30°C (for example, in the absence of sunlight or at night), the first solenoid valve provided at the water inlet of the solar water tank is closed, and the second solenoid valve provided at the water inlet of the air source heat pump is opened, so that the water flows to the air source heat pump, and is heated by the air source heat pump to ensure hot water for users. The first temperature threshold can be adjusted according to actual user needs.

[0052] Specifically, a first water pump group is provided at the water outlet of the solar water tank, which is used to control the flow direction of water at the water outlet of the solar water tank;

[0053] The water outlet of the heat pump water tank is provided with a second water pump group for controlling the water flow direction of the water outlet of the heat pump water tank;

[0054] The first water pump group and the second water pump group are powered by the photovoltaic assembly.

[0055] Furthermore, a return pipe is connected between the first water pump group and the water outlet of the solar water tank for recovering and circulating unused water at the user end.

[0056] Furthermore, the first water pump group and the second water pump group respectively include two water pumps for backup in case of water pump group failure.

[0057] In this embodiment, in order to ensure that the water flow can circulate in the specified direction, the first water pump group and the second water pump group are set in the system. Each water pump group includes two water pumps, one water pump is used for normal operation, and the other water pump is used as a backup when the normally working water pump fails, so as to ensure that the water supply to the user is not interrupted. The user end is also provided with a return pipe connected to the first water pump group, which circulates to the vacuum collector tube through the first water pump group for heating, and recycles the water not used by the user for recycling, saving water resources.

[0058] Furthermore, the cold water inlet end of the solar water tank and the cold water inlet end of the heat pump water tank are respectively connected to cold water supply pipes; the cold water inlet end of the solar water tank is provided with a third solenoid valve, and the cold water inlet end of the heat pump water tank is provided with a fourth solenoid valve; the control ends of the third solenoid valve and the fourth solenoid valve are respectively remotely connected to the host computer, for remotely controlling the opening and closing of the third solenoid valve and the fourth solenoid valve according to time or weather conditions.

[0059] Furthermore, the water supply end of the heat pump water tank is connected to a water supply pipe for providing hot water to users.

[0060] In this embodiment, the solar water tank and the heat pump water tank are respectively supplied with cold water, and the cold water pipes of the two water tanks are respectively provided with solenoid valves. If the sunlight conditions are good, that is, when the sun can be used for heating, the third solenoid valve is opened by the host computer, and the cold water is heated by solar energy; if it is cloudy or rainy, the fourth solenoid valve is opened by the host computer, and the cold water is heated by the air source heat pump. The host computer can be adjusted by real-time weather forecast; or the host computer can be set to adjust in time periods. If it is during the daytime, the third solenoid valve is opened by the host computer, and the cold water is heated by solar energy; if it is at night, the fourth solenoid valve is opened by the host computer, and the cold water is heated by the air source heat pump, which ensures the energy saving and circulation of the entire PVT system. Hot water is directly provided to users through the water supply pipe of the heat pump water tank to ensure the stability of the hot water temperature. If the solar water tank is directly used to supply water to users, the water temperature cannot be well guaranteed due to the large fluctuation of the water temperature of the solar water tank.

[0061] The above descriptions are only some embodiments of the present invention, and do not limit the protection scope of the present invention. Any equivalent device or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly used in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A PVT system based on Fresnel lens, characterized in that: include: A Fresnel lens, a vacuum heat collecting tube, and a photovoltaic module are arranged in sequence and spaced apart from each other. The Fresnel lens is used to focus sunlight on the vacuum heat collecting tube to heat water in the vacuum heat collecting tube. The photovoltaic module is used to obtain and store solar energy. The water outlet of the vacuum heat collecting tube is connected to the water inlet of the solar water tank through a pipeline, and the water inlet of the vacuum heat collecting tube is connected to the water outlet of the solar water tank through a pipeline, so as to heat the water stored in the solar water tank by using solar energy circulation; The water outlet end of the vacuum heat collecting tube is connected to the water inlet end of the air source heat pump through a pipeline, the water outlet end of the air source heat pump is connected to the heat pump water tank, and the water outlet end of the heat pump water tank is connected to the water inlet end of the air source heat pump, so as to use the air source heat pump to circulate and heat the water stored in the heat pump water tank, and the air source heat pump is powered by the photovoltaic module.

2. A PVT system based on a Fresnel lens according to claim 1, characterized in that: The distance between the Fresnel lens and the vacuum heat collecting tube is set to 0.3-0.7m.

3. The PVT system based on Fresnel lens according to claim 1, characterized in that: The photovoltaic assembly includes a photovoltaic panel, an inverter, and an energy storage system connected in sequence; The photovoltaic panel is used to collect solar energy; The inverter is used to convert and adjust the direct current obtained by the photovoltaic panel into alternating current; The energy storage system is used to store the electric energy obtained by the photovoltaic panel and converted and adjusted by the inverter.

4. The PVT system based on Fresnel lens according to claim 1, characterized in that: The water inlet end of the solar water tank is provided with a first solenoid valve, and the water inlet end of the air source heat pump is provided with a second solenoid valve; A temperature sensing control unit is provided at the water outlet end of the vacuum heat collecting tube for obtaining the water outlet temperature of the vacuum heat collecting tube. The temperature sensing control unit is respectively connected to the control end of the first solenoid valve and the control end of the second solenoid valve for closing the first solenoid valve and opening the second solenoid valve when the water outlet temperature of the water outlet end of the vacuum heat collecting tube is lower than a first temperature threshold.

5. A PVT system based on a Fresnel lens according to claim 4, characterized in that: The first temperature threshold is 30°C.

6. A PVT system based on a Fresnel lens according to claim 1, characterized in that: The water outlet of the solar water tank is provided with a first water pump group for controlling the water flow direction of the water outlet of the solar water tank; A second water pump group is provided at the water outlet of the heat pump water tank, which is used to control the water flow direction of the water outlet of the heat pump water tank; The first water pump group and the second water pump group are powered by the photovoltaic assembly.

7. A PVT system based on a Fresnel lens according to claim 6, characterized in that: A return pipe is connected between the first water pump group and the water outlet of the solar water tank to recycle and circulate unused water at the user end.

8. A PVT system based on a Fresnel lens according to claim 6, characterized in that: The first water pump group and the second water pump group respectively include two water pumps for backup in case of water pump group failure.

9. The PVT system based on Fresnel lens according to claim 1, characterized in that: The cold water inlet end of the solar water tank and the cold water inlet end of the heat pump water tank are respectively connected to cold water supply pipes; the cold water inlet end of the solar water tank is provided with a third solenoid valve, and the cold water inlet end of the heat pump water tank is provided with a fourth solenoid valve; the control ends of the third solenoid valve and the fourth solenoid valve are respectively remotely connected to the host computer, for remotely controlling the opening and closing of the third solenoid valve and the fourth solenoid valve according to time or weather conditions.

10. The PVT system based on Fresnel lens according to claim 1, characterized in that: The water supply end of the heat pump water tank is connected to a water supply pipe for providing hot water to users.

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