PVT coupling phase change energy storage system
By combining heat exchange units and cascaded phase change thermal storage devices in a PVT system, and utilizing various phase change materials and control and regulation systems, the problems of reduced photovoltaic cell efficiency and unstable thermal storage have been solved, achieving efficient and stable thermal storage and heating effects.
Patent Information
- Application Number
- CN202520180997.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-05
- Publication Date
- 2026-01-16
- Estimated Expiration
- 2035-02-05
AI Technical Summary
In existing PVT systems, the power generation efficiency of photovoltaic cells decreases as temperature increases, the installation area of the photothermal conversion system is limited and the efficiency is low, the heat storage effect is not ideal, and the heat transfer efficiency of the phase change heat storage system fluctuates greatly.
By combining PVT components with heat exchange units and setting up a tiered phase change heat storage device, different phase change heat storage devices can be switched by adjusting valves through a control and regulation system. Combined with insulation layers and various phase change materials, stable heat storage and efficient heat exchange can be achieved.
This improves the heat exchange efficiency and heat storage effect of the PVT system, reduces the impact of temperature fluctuations on system efficiency, and ensures the stability and efficient operation of the heating system.
Smart Images
Figure CN223807669U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to building energy storage technical field especially a PVT coupling phase change energy storage system. BACKGROUND
[0002] At present, the utilization of solar energy has two main ways of photoelectric conversion and photothermal conversion, however, for single solar energy utilization, many problems will be produced, such as the photovoltaic cell power generation efficiency reduces with the temperature rise of photovoltaic panel under sunlight irradiation, and the solar water heating system using the photothermal conversion principle has limited installation area, low conversion efficiency, insufficient heat reserve and supply etc., in response to the above technical defects, photovoltaic-thermal integration (PVT) is gradually widely used, but the heat exchange efficiency and heat storage effect are not ideal, and are greatly influenced by environment, climate and time.
[0003] The existing heat storage technology mainly includes sensible heat storage, latent heat storage and chemical reaction heat storage, latent heat storage is phase change heat storage, and the advantage lies in its high heat storage density and good stability, which can improve the overall energy storage efficiency of the system. In the current research on PVT-PCM system, the energy storage medium is mainly single phase change material, and the problem is that with the heat storage and heat release, the heat transfer efficiency will fluctuate according to the change of heat exchange temperature difference. SUMMARY
[0004] The utility model aims at overcoming the above-mentioned insufficient, provides a kind of PVT coupling phase change energy storage system, under the condition of improving heat exchange efficiency and heat storage effect, improve the stability of phase change heat storage system, avoid the overall efficiency of heating system to be fluctuated by the change of heat exchange temperature difference.
[0005] To solve the above technical problems, the technical scheme adopted by the utility model is: a PVT coupling phase change energy storage system, comprising a PVT component, a heat exchange unit, a heat exchange device, a cascade phase change heat storage device and a user-side water tank, the back plate of the PVT component is coupled with the heat exchange unit, the outlet end of the heat exchange unit is connected with the medium inlet of the heat exchange device through a pipeline, the medium outlet of the heat exchange device is connected with the input end of the cascade phase change heat storage device through a pipeline, the output end of the cascade phase change heat storage device is connected with the inlet of the heat exchange unit through a pipeline, the water outlet of the heat exchange device is connected with the backwater outlet of the user-side water tank through a pipeline, and the water outlet of the user-side water tank is connected with the water inlet of the heat exchange device through a pipeline.
[0006] Preferably, it further comprises a fluid pipeline system for connecting the heat exchange unit, the heat exchange device, the cascade phase change heat storage device and the user-side water tank, and a control and adjustment system is arranged on the fluid pipeline system.
[0007] Preferably, the fluid pipeline system comprises water pipelines for connecting the heat exchange device and the user-side water tank, and heat exchange medium pipelines for connecting the heat exchange unit, the heat exchange device and the stepped phase change heat storage device.
[0008] Preferably, the water pipelines comprise water supply pipelines and water return pipelines, the water outlet of the user-side water tank is connected to the water inlet of the heat exchange device through the water supply pipelines, and the water outlet of the heat exchange device is connected to the water return inlet of the user-side water tank through the water return pipelines.
[0009] Preferably, the heat exchange medium pipelines comprise first heat exchange medium pipelines, second heat exchange medium pipelines and third heat exchange medium pipelines, the outlet end of the heat exchange unit is connected to the medium inlet of the heat exchange device through the first heat exchange medium pipelines, the medium outlet of the heat exchange device is connected to the input end of the stepped phase change heat storage device through the second heat exchange medium pipelines, and the output end of the stepped phase change heat storage device is connected to the inlet of the heat exchange unit through the third heat exchange medium pipelines.
[0010] Preferably, the first heat exchange medium pipelines are further connected to the second heat exchange medium pipelines through fourth heat exchange medium pipelines.
[0011] Preferably, the heat exchange unit comprises an insulating layer on the outer side, a plurality of heat transfer fluid pipes are arranged in the insulating layer, one side of the heat transfer fluid pipes is in contact with the heat transfer plates, the other side of the heat transfer plates is in contact with the back plate of the PVT assembly, and the heat exchange medium is arranged in the heat transfer fluid pipes.
[0012] Preferably, the stepped phase change heat storage device comprises heat storage tanks of phase change materials with three reference temperature intervals, which are low-temperature PCM heat storage tanks, medium-temperature PCM heat storage tanks and high-temperature PCM heat storage tanks, wherein the reference temperature interval of the phase change material of the low-temperature PCM heat storage tank is 25-35℃, the reference temperature interval of the phase change material of the medium-temperature PCM heat storage tank is 40-50℃, and the reference temperature interval of the phase change material of the high-temperature PCM heat storage tank is 55-70℃.
[0013] Preferably, the control and adjustment system comprises temperature sensors, pressure sensors, flow meters, circulating water pumps and valves arranged on the water pipelines and the heat exchange medium pipelines.
[0014] Preferably, the water outlet of the user-side water tank is further provided with a hot water outlet pipeline, a one-way valve is arranged at a position close to the water outlet of the user-side water tank in the water supply pipelines, and a cold water inlet pipeline is arranged at a position away from the water outlet of the user-side water tank in the water supply pipelines.
[0015] The utility model discloses beneficial effect: the utility model discloses the heat exchange unit with PVT backboard combination, and set up the phase change heat storage device of different temperature gradient, according to heat collecting device temperature distribution, through control adjustment system adjusting valve switch different phase change heat storage device and store energy, can improve the stability of phase change heat storage system under the condition of improving heat exchange efficiency and heat storage effect, avoid the overall efficiency of heating system to change and produce fluctuation of heat transfer temperature difference. BRIEF DESCRIPTION OF DRAWINGS
[0016] Fig. 1 It is a kind of PVT coupling phase change energy storage system's structural schematic diagram;
[0017] Fig. 2 It is the internal structure schematic diagram of PVT component and heat exchange unit connection. DETAILED DESCRIPTION
[0018] The utility model will be further described in detail in combination with the drawings and specific embodiment.
[0019] As Figs. 1-2 Shown, a kind of PVT coupling phase change energy storage system, including PVT component 1, heat exchange unit 2, heat exchange device 3, gradient phase change heat storage device 4 and user side water tank 5, the backplate of PVT component 1 is coupled with heat exchange unit 2, the outlet end of heat exchange unit 2 is connected with the medium inlet of heat exchange device 3 by pipeline, the medium outlet of heat exchange device 3 is connected with the input end of gradient phase change heat storage device 4 by pipeline, the output end of gradient phase change heat storage device 4 is connected with the inlet of heat exchange unit 2 by pipeline, the water outlet of heat exchange device 3 is connected with the backwater of user side water tank 5 by pipeline, the water outlet of user side water tank 5 is connected with the water inlet of heat exchange device 3 by pipeline.In this embodiment, the backplate of PVT component 1 is coupled with heat exchange unit 2, due to the high efficient heat transfer capacity of heat exchange medium, the heat transfer between backplate and heat exchange unit inner heat transfer fluid pipe can be promoted, the temperature of the backplate of PVT component 1 is effectively reduced, so that PVT component 1 can work at more uniform temperature;And the heat generated by PVT component 1 can be transferred to heat exchange device 3 for heat exchange or to gradient phase change heat storage device 4 of different temperature for storage by the flow of heat fluid.
[0020] Preferably, it further includes fluid pipe system 6 for connecting heat exchange unit 2, heat exchange device 3, gradient phase change heat storage device 4 and user side water tank 5, and control adjustment system 7 is arranged on fluid pipe system 6.
[0021] Preferably, fluid pipe system 6 includes water pipe 6-1 for connecting heat exchange device 3 and user side water tank 5 and heat exchange medium pipe 6-2 for connecting heat exchange unit 2, heat exchange device 3 and gradient phase change heat storage device 4.
[0022] Preferably, the water pipeline 6-1 includes a water supply pipeline 6-1a and a water return pipeline 6-1b, the water outlet of the user-side water tank 5 is connected with the water inlet of the heat exchange device 3 through the water supply pipeline 6-1a, and the water outlet of the heat exchange device 3 is connected with the water return outlet of the user-side water tank 5 through the water return pipeline 6-1b.
[0023] Preferably, the heat exchange medium pipeline 6-2 includes a first heat exchange medium pipeline 6-2a, a second heat exchange medium pipeline 6-2b and a third heat exchange medium pipeline 6-2c, the outlet end of the heat exchange unit 2 is connected with the medium inlet of the heat exchange device 3 through the first heat exchange medium pipeline 6-2a, the medium outlet of the heat exchange device 3 is connected with the input end of the cascade phase change heat storage device 4 through the second heat exchange medium pipeline 6-2b, and the output end of the cascade phase change heat storage device 4 is connected with the inlet of the heat exchange unit 2 through the third heat exchange medium pipeline 6-2c.
[0024] Preferably, the first heat exchange medium pipeline 6-2a is further connected with the second heat exchange medium pipeline 6-2b through a fourth heat exchange medium pipeline 6-2d. The design is mainly to open the valve on the fourth heat exchange medium pipeline 6-2d when the heat exchange of the heat exchange device is not needed, and the heat exchange medium in the heat transfer fluid pipe 2-2 in the heat exchange unit 2 is directly sent into the cascade phase change heat storage device 4 through the first heat exchange medium pipeline 6-2a, the fourth heat exchange medium pipeline 6-2d and the second heat exchange medium pipeline 6-2b for heat storage process.
[0025] Preferably, the heat exchange unit 2 includes an insulation layer 2-1 on the outside, a plurality of heat transfer fluid pipes 2-2 are arranged in the insulation layer 2-1, one side of the heat transfer fluid pipe 2-2 is in contact with a heat transfer plate 2-3, the other side of the heat transfer plate 2-3 is in contact with the back plate of the PVT assembly 1, and the heat transfer fluid pipe 2-2 is provided with heat exchange medium. In this embodiment, the outlet end of the heat transfer fluid pipe 2-2 is connected with the medium inlet of the heat exchange device 3 through the first heat exchange medium pipeline 6-2a, and the output end of the cascade phase change heat storage device 4 is connected with the inlet of the heat transfer fluid pipe 2-2 through the third heat exchange medium pipeline 6-2c. More preferably, the heat exchange device 3 adopts a finned tube heat exchanger.
[0026] Preferably, the stepped phase change heat storage device 4 comprises heat storage tanks of phase change materials provided with three kinds of reference temperature intervals, namely a low-temperature PCM heat storage tank 4-1, a medium-temperature PCM heat storage tank 4-2 and a high-temperature PCM heat storage tank 4-3, wherein the reference temperature interval of the phase change material of the low-temperature PCM heat storage tank 4-1 is 25-35°C, the reference temperature interval of the phase change material of the medium-temperature PCM heat storage tank 4-2 is 40-50°C, and the reference temperature interval of the phase change material of the high-temperature PCM heat storage tank 4-3 is 55-70°C. In this embodiment, the low temperature (25-35°C) is suitable for heat storage under normal temperature and daytime low temperature conditions; the medium temperature (40-50°C) is suitable for heat storage under stable daytime working conditions; and the high temperature (55-70°C) can store the high-temperature peak heat of the PVT system and is suitable for extreme high temperature weather, high PVT temperature and long-time heat storage requirements. This embodiment uses phase change materials with three kinds of reference temperature intervals, sets a stepped phase change heat storage device, and uses organic PCM, nano-enhanced organic PCM, inorganic PCM and nano-enhanced inorganic PCM according to low temperature and medium-high temperature, so as to meet the heat storage requirements under different working conditions, have a wider application range and have higher system stability.
[0027] Optionally, the combination of multiple phase change materials can be adjusted according to the actual working conditions such as the ambient temperature and the output heat of the PVT system. The low-melting-point PCM can be used to cope with daytime temperature fluctuations, and the high-melting-point PCM can release more energy when long-time heat storage is required. The low-temperature layer uses organic PCM, which has stable performance at low temperature and is suitable for night heat preservation; or nano-enhanced organic PCM can be used to improve the thermal conductivity and speed up heat transfer. The medium-temperature layer and the high-temperature layer use inorganic PCM, which has high latent heat of phase change and good thermal conductivity, and is suitable for heat storage under stable daytime temperature; or nano-enhanced inorganic PCM can be used to significantly improve the thermal conductivity and ensure rapid heat absorption and phase change during the day.
[0028] Preferably, the phase change material is in the form of capsule-shaped packaging and is uniformly stacked in the stepped phase change heat storage device 4. The capsule-shaped packaging of the phase change material is better than the traditional spherical packaging and is more suitable for rapid heat exchange conditions. The capsule shape has a higher surface area to volume ratio, increasing the contact area with the heat transfer medium, so that it has a higher heat exchange rate in unit volume; the heat conduction path of the cylindrical body is shorter, and the internal heat is transferred to the surface more efficiently; in the heat storage tank, the PCM particles in the form of capsules form greater fluid turbulence, enhancing the heat exchange effect. More preferably, the PCM particles in the form of capsules can be fixed in the PCM heat storage tank through a filter screen, so that the heat transfer medium can pass through the filter screen and the PCM particles in the form of capsules for the heat exchange process, while not affecting the passage of the heat transfer medium through the entire heat storage tank.
[0029] Preferably, the control adjustment system 7 comprises temperature sensors 7-1, pressure sensors 7-2, flow meters 7-3, circulating water pumps 7-4 and valves 7-5 arranged on the water pipeline 6-1 and the heat exchange medium pipeline 6-2. The temperature, pressure and flow of the fluid can be monitored by the temperature sensors 7-1, the pressure sensors 7-2 and the flow meters 7-3; the circulating water pumps 7-4 on the heat exchange medium pipeline 6-2 can enable the fluid to circulate between the heat exchange units, the heat exchange devices and the cascade phase change heat storage devices, so as to carry out the heat storage and heat exchange processes; the circulating water pumps 7-4 on the water pipeline 6-1 can enable the fluid to circulate between the heat exchange devices and the user-side water tank, so as to carry out the heating process on the user-side water tank.
[0030] Preferably, the user-side water tank 5 is further provided with a hot water outlet pipeline 5-1, a one-way valve 5-2 is arranged on the water supply pipeline 6-1a near the water outlet of the user-side water tank 5, and a cold water inlet pipeline 5-3 is arranged on the one-way valve 5-2 away from the water outlet of the user-side water tank 5. The cold water inlet pipeline 5-3 can supplement cold water to be heated to the water supply pipeline 6-1a, and after being heated by the heat exchange device 3, the cold water flows into the user-side water tank 5; the one-way valve 5-2 can prevent the cold water in the cold water inlet pipeline 5-3 from flowing back into the user-side water tank.
[0031] The working process of the utility model is as follows:
[0032] 1. Under normal working conditions, efficient heat absorption and storage during the day;
[0033] When the PVT component is heated by solar radiation, the heat exchange unit integrated in the back plate absorbs heat, and as the temperature rises to a stable working condition, the heat exchange medium in the heat transfer fluid pipe 2-2 continuously transfers heat to the heat exchange device, and exchanges heat with the water in the user-side water tank. The remaining heat after heat exchange is transferred to the heat storage tank by the heat exchange medium for heat storage. Or according to the climate and working condition changes, the heat exchange medium in the heat transfer fluid pipe 2-2 is directly transferred to the heat storage tank corresponding to the temperature interval of the cascade phase change heat storage device for heat storage. In this way, not only can the temperature of the PVT component be reduced, but also the temperature can be evenly distributed to improve the power generation efficiency, and the heat can be stored to the maximum extent.
[0034] 2. Under extreme high temperature conditions, efficient heat absorption and storage during the day;
[0035] When extreme high temperature climate is encountered, or when located in an area with high solar energy resources, the PVT component is heated by solar radiation, and the excess heat is transferred to the heat exchange device by the heat exchange medium in the heat transfer fluid pipe 2-2, and exchanges heat with the water in the user-side water tank. The waste heat is transferred to the cascade phase change heat storage device 4 for heat storage for use at night.
[0036] 3. Energy supply under night or low light conditions;
[0037] As the ambient temperature decreases, the phase change material gradually releases the heat stored during the day. The system first uses the low-temperature PCM heat storage tank in the cascade phase change heat storage device to exchange heat with the heat exchange device. As the heat exchange process proceeds, the medium-temperature and high-temperature PCM heat storage tanks are called in turn. This cascade phase change storage ensures that the system can continuously supply heat, especially at night or in cold conditions.
[0038] During the adjustment according to different working conditions, the low-temperature PCM heat storage tank, the medium-temperature PCM heat storage tank, and the high-temperature PCM heat storage tank circuit can be controlled by the electromagnetic valve; alternatively, the heat exchange medium can be transferred to the corresponding temperature heat storage tank 4 for heat storage, or heat exchange in the heat exchange device 3. That is, the system can be equipped with a temperature control device, which uses an electromagnetic valve to control the PVT assembly and the heat exchange unit according to the demand, and the heat transfer between the heat exchange unit, the cascade phase change heat storage device, and the user-side water tank, to meet the all-weather heat exchange and heat storage requirements of the building, greatly improve the energy efficiency of the PVT assembly, optimize energy storage management, and provide strong and effective support for clean energy application of the building.
[0039] The above-described embodiments are only preferred technical solutions of the present application, and should not be regarded as limiting the present application. The protection scope of the present application should be based on the technical solutions claimed in the claims, including equivalent replacement solutions of the technical features claimed in the claims. That is, equivalent replacement improvements within this scope are also within the protection scope of the present application.
Claims
1. A PVT coupled phase change thermal storage system comprising a PVT assembly (1), a heat exchange unit (2), a heat exchange device (3), a stepped phase change thermal storage device (4) and a user side water tank (5), characterized in that: The PVT assembly (1) back plate is coupled with the heat exchange unit (2), the outlet end of the heat exchange unit (2) is connected with the medium inlet of the heat exchange device (3) through a pipeline, the medium outlet of the heat exchange device (3) is connected with the input end of the cascade phase change heat storage device (4) through a pipeline, the output end of the cascade phase change heat storage device (4) is connected with the inlet of the heat exchange unit (2) through a pipeline, the water outlet of the heat exchange device (3) is connected with the backwater outlet of the user side water tank (5) through a pipeline, and the water outlet of the user side water tank (5) is connected with the water inlet of the heat exchange device (3) through a pipeline.
2. The PVT coupled PCMs system of claim 1, wherein: Further comprising a fluid pipeline system (6) for connecting the heat exchange unit (2), the heat exchange device (3), the cascade phase change heat storage device (4) and the user side water tank (5), and a control and adjustment system (7) is arranged on the fluid pipeline system (6).
3. The PVT coupled PCMs system of claim 2, wherein: The fluid pipeline system (6) comprises a water pipeline (6-1) for connecting the heat exchange device (3) and the user side water tank (5), and a heat exchange medium pipeline (6-2) for connecting the heat exchange unit (2), the heat exchange device (3) and the cascade phase change heat storage device (4).
4. The PVT coupled PCMs system of claim 3, wherein: The water pipeline (6-1) comprises a water supply pipeline (6-1a) and a backwater pipeline (6-1b), the water outlet of the user side water tank (5) is connected with the water inlet of the heat exchange device (3) through the water supply pipeline (6-1a), and the water outlet of the heat exchange device (3) is connected with the backwater outlet of the user side water tank (5) through the backwater pipeline (6-1b).
5. The PVT coupled PCMs system of claim 3, wherein: The heat exchange medium pipeline (6-2) comprises a first heat exchange medium pipeline (6-2a), a second heat exchange medium pipeline (6-2b) and a third heat exchange medium pipeline (6-2c), the outlet end of the heat exchange unit (2) is connected with the medium inlet of the heat exchange device (3) through the first heat exchange medium pipeline (6-2a), the medium outlet of the heat exchange device (3) is connected with the input end of the cascade phase change heat storage device (4) through the second heat exchange medium pipeline (6-2b), and the output end of the cascade phase change heat storage device (4) is connected with the inlet of the heat exchange unit (2) through the third heat exchange medium pipeline (6-2c).
6. The PVT coupled PCMs system of claim 5, wherein: The first heat exchange medium pipeline (6-2a) is further connected with the second heat exchange medium pipeline (6-2b) through a fourth heat exchange medium pipeline (6-2d).
7. The PVT coupled PCMs system of claim 1, wherein: The heat exchange unit (2) comprises an insulation layer (2-1) located on the outer side, a plurality of heat transfer fluid pipes (2-2) are arranged in the insulation layer (2-1), one side of the heat transfer fluid pipe (2-2) is in contact with a heat transfer plate (2-3), the other side of the heat transfer plate (2-3) is in contact with the back plate of the PVT assembly (1), and the heat transfer fluid pipe (2-2) is provided with a heat exchange medium.
8. The PVT coupled PCMs system of claim 1, wherein: The step change heat storage device (4) comprises heat storage tanks provided with phase change materials with three kinds of reference temperature intervals, namely a low-temperature PCM heat storage tank (4-1), a medium-temperature PCM heat storage tank (4-2) and a high-temperature PCM heat storage tank (4-3), wherein the reference temperature interval of the phase change material of the low-temperature PCM heat storage tank (4-1) is 25-35 DEG C, the reference temperature interval of the phase change material of the medium-temperature PCM heat storage tank (4-2) is 40-50 DEG C, and the reference temperature interval of the phase change material of the high-temperature PCM heat storage tank (4-3) is 55-70 DEG C.
9. The PVT coupled PCMs system of claim 3, wherein: The control and adjustment system (7) comprises temperature sensors (7-1), pressure sensors (7-2), flow meters (7-3), circulating water pumps (7-4) and valves (7-5) arranged on the water pipeline (6-1) and the heat exchange medium pipeline (6-2).
10. The PVT coupled PCMs system of claim 4, wherein: The water outlet of the user-side water tank (5) is further provided with a hot water outlet pipeline (5-1), the water supply pipeline (6-1a) is provided with a one-way valve (5-2) near the water outlet of the user-side water tank (5), and the one-way valve (5-2) is provided with a cold water inlet pipeline (5-3) away from the water outlet of the user-side water tank (5).