Loop heat pipe and water heat storage coupling system and working method

Abstract

The invention discloses a loop heat pipe and water heat storage coupling system and a working method, and belongs to the technical field of heat storage. The system has the modes of light gathering of the light-following trough heat collector, heat conduction of the loop heat pipe, heat storage of the water storage tank and warm water irrigation by using the stored heat water. When sunlight is sufficient in the daytime, the system converts solar energy into sensible heat of water in the heat storage water tank and stores the sensible heat, and the sensible heat is insulated by soil to slow down heat loss; when plants need to be irrigated, warm water in the irrigation water tank is used for irrigation; at night or in the absence of illumination, warm water in the heat storage water tank exchanges heat with air in the greenhouse, so that a lasting and stable heat supply source is provided for the greenhouse. Solar energy collected by the heat collecting groove is efficiently transmitted into the water tank through the loop heat pipe driven by temperature difference to be converted into sensible heat of water to be stored, the sensible heat is used for increasing the greenhouse temperature and irrigating plants when heat is needed at night, and the purposes of efficiently storing heat in the daytime and continuously supplying heat at night are integrally achieved.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of heat storage, in particular to a loop heat pipe and water heat storage coupling system and a working method. BACKGROUND

[0002] Solar energy, as a renewable and clean energy, has the significant advantages of unlimited reserves and environmental friendliness, and shows a broad application prospect in the field of heat supply. However, due to the influence of day and night cycles, solar heat utilization has a significant intermittent defect, and it is difficult to realize continuous and stable heat supply. Especially in winter night, when the heat load of facilities such as greenhouses reaches the peak, the solar radiation completely disappears, which causes the traditional solar heat supply system to face the problem of serious intermittent heat supply. As a key supplement measure of the solar heat utilization system, the heat storage technology can effectively solve the time and space mismatch problem of day and night energy supply and demand, and can provide reliable heat supply for winter greenhouse and other high heat demand scenes, so as to realize the continuous and stable supply of heat energy. SUMMARY

[0003] The purpose of the application is to provide a continuous and stable heat source for greenhouses, which can meet the night growth needs of crops in greenhouses. The heat storage device is based on the transformation of ordinary wall greenhouse and mainly consists of three structures. The first part is a trough type solar light tracking collector, which is used as a solar energy collecting device to realize efficient light collection and heat collection. The second part is a loop heat pipe, which relies on high thermal conductivity to ensure efficient heat transfer. The third part is a water storage tank, which is used as a low-cost heat storage device to realize heat storage and release.

[0004] In order to realize the above technical features, the purpose of the application is realized as follows: a loop heat pipe and water heat storage coupling system, in which the trough type solar light tracking collector focuses sunlight on the hot end of the loop heat pipe, and the heat is efficiently transferred to the cold end of the loop heat pipe under the driving of temperature difference, so as to heat the cold water in the heat exchange part of the water storage tank. The valve is monitored and controlled by a temperature monitor to adjust the communication state with the heat storage irrigation part of the water storage tank. The water storage tank is in the shape of a ridge, which is composed of a heat exchange part and a heat storage irrigation part, and is covered with a soil layer. The top is provided with a water inlet, and the bottom is provided with a drainage outlet and an auxiliary heating device.

[0005] The heat storage irrigation part of the water storage tank is in communication with the heat exchange part of the water storage tank through the valve control. The drip irrigation device is arranged on both sides of the main body of the heat storage irrigation part, and directly guides the planted crops. The top of the heat storage irrigation part is in communication with the heat exchange part of the water storage tank through the valve control, and the bottom is provided with a drainage outlet in communication with the outside.

[0006] The working method of the loop heat pipe and water heat storage coupling system includes the following processes:

[0007] Heat collection of the trough type solar collector:

[0008] The trough type solar heat collection system first provides electric energy by a photovoltaic panel to drive a light tracking system to adjust the angle of the parabolic trough reflector in real time, so that the parabolic trough reflector is always aligned with the sun, and high-efficiency light collection is realized.

[0009] High-efficiency heat transfer of the loop heat pipe:

[0010] The high-temperature heat energy collected by the trough type heat collector drives the liquid-gas phase change of the working medium in the loop heat pipe, the gas quickly transfers to the cold end and releases heat energy, and the condensed gas returns to the hot end to continue working;

[0011] Heat storage of the water storage tank:

[0012] When the high-temperature gaseous phase change working medium enters the condensing end of the loop heat pipe, the internal steam exchanges heat with the condenser wall through convection, and the heat is transferred to the metal wall; the outer wall of the condenser transfers the heat to the heat exchange surface connected with the water storage tank through conduction, and then transfers the heat to the low-temperature water medium in the water tank through convection heat exchange.

[0013] Heat release of the water storage tank:

[0014] When the system monitors that the temperature or humidity in the shed is lower than the set threshold, the control valve between the heat exchange unit and the irrigation system is automatically opened. The warm water flows through the distributed irrigation pipe network under the drive of the water pump, and uniformly releases heat to the shed through radiation and convection. This process not only ensures the temperature of the irrigation water, but also effectively maintains the temperature and humidity balance of the greenhouse environment, and realizes the efficient recycling of heat energy.

[0015] The system comprises a light tracking system, a trough type solar heat collector, a loop heat pipe, a water storage tank, a solar power panel and a temperature detector.

[0016] The volume design of the loop heat pipe and the water storage tank needs to be calculated according to local sunshine conditions, temperature conditions and other factors, and the filling ratio of the phase change material can be adjusted according to the season.

[0017] The temperature detector can monitor the indoor temperature change in real time, and facilitate the adjustment of the next process.

[0018] The loop heat pipe and water heat storage coupling system have the advantages of high heat storage density, high heat storage and release efficiency, good diurnal continuity, fast response speed, etc.

[0019] The system is transformed on the basis of common wall greenhouse and is sequentially provided with a groove type solar light tracking collector, a loop heat pipe and a water storage tank from top to bottom, and comprises a groove type solar light tracking collector condensing mode, a loop heat pipe heat conducting mode, a water storage tank water storage and heat storage mode and a warm water irrigation mode using the heat storage water.

[0020] The system is transformed on the basis of common wall greenhouse and is sequentially provided with a groove type solar light tracking collector, a loop heat pipe and a water storage tank from top to bottom, and comprises a groove type solar light tracking collector condensing mode, a loop heat pipe heat conducting mode, a water storage tank water storage and heat storage mode and a warm water irrigation mode using the heat storage water.

[0021] Advantages of the present application:

[0022] The existing solar-based heating device cannot store heat and has low heat transfer efficiency, and the system operation excessively relies on additional power input. The present application uses the loop heat pipe driven by temperature difference to efficiently transfer the solar energy collected by the heat collection groove to the water tank to convert it into the sensible heat of water for storage, and to use it to raise the temperature of the greenhouse at night when heat is needed, and to use its suitable temperature for warm water irrigation of plants, thereby preventing plant frost damage from the root, and achieving the purposes of high efficiency heat storage during the day and continuous heat supply at night.

[0023] The present application combines solar heat utilization with greenhouse heating and crop irrigation, efficiently utilizes solar energy, does not need power and other consumer energy input, and helps to create an efficient and low-carbon greenhouse system. At the same time, the loop heat pipe efficiently transfers heat, relies on temperature difference to quickly and passively transfer heat energy to the water storage tank without external power input. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced as follows.

[0025] Figure 1 System overall energy flow conversion schematic diagram.

[0026] Figure 2 Overall system device schematic diagram.

[0027] Figure 3 Loop heat pipe and water storage tank feature schematic diagram.

[0028] Figure 4 Water storage tank heat storage irrigation section view.

[0029] 1, trough solar light tracking collector, 101, heat collecting trough, 102, light tracking system, 103, photovoltaic panel, 2, loop heat pipe, 201, loop heat pipe hot end, 202, loop heat pipe adiabatic section, 203, loop heat pipe cold end; 3, water storage tank, 301, water storage tank heat exchange part, 302, water storage tank heat storage irrigation part, 3021, heat storage water cavity, 3022, irrigation water cavity, 303, water inlet, 304, water inlet pipe, 305, irrigation water inlet, 306, drip irrigation pipe, 307, total water outlet; 4, temperature monitor, 5, drain valve, 6, auxiliary heating device, 7, field ridge insulation soil layer, 8, crop, 9, humidity monitor. DETAILED DESCRIPTION

[0030] The specific embodiments of the present application will be further described in conjunction with the drawings and technical solutions.

[0031] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings of the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. The description of the at least one exemplary embodiment is actually only illustrative, but not as any limitation on the present application and its application or use. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0032] It should be noted that the terms used herein are only for describing specific embodiments, and are not intended to limit the exemplary embodiments according to the present application. As used herein, the singular form is intended to include the plural form unless the context clearly indicates otherwise, and furthermore, it should be understood that when the terms "comprise" and / or "include" are used in the specification, there is a feature, step, operation, device, component and / or combination thereof.

[0033] Embodiment 1

[0034] Figure 1 is a schematic diagram of the overall energy flow of the system. In the figure: hollow arrows represent heat in the form of light and transfer, solid arrows represent heat transfer by convection or conduction, and line arrows represent the direction of overall heat transfer. Heat is concentrated from the heat collecting trough to the loop heat pipe, the loop heat pipe transfers heat to the cold end, and the loop heat pipe exchanges heat with the heat storage water to release heat to the shed at night.

[0035] Figure 2 、 Figure 3 and Figure 4A greenhouse based on a loop heat pipe and water heat storage coupling system is shown, in which a trough type solar collector 1 tracks the sun in real time through a photosensitive element to obtain the best collection position, which is opposite to the hot end part of the loop heat pipe 2, and then the collected solar energy is efficiently transferred to the loop heat pipe, under the action of temperature difference driving force, the loop heat pipe is automatically started, and the heat is automatically transferred to the cold end part of the loop heat pipe, and because the cold end is immersed in the water storage tank 3, heat exchange is carried out with it, and the whole heat transfer process is completed.

[0036] Specifically, the system includes a trough type solar light tracking collector 1, a loop heat pipe 2 and a water storage tank 3. In the trough type solar light tracking collector 1, a heat collecting trough 101, a light tracking system 102 and a photovoltaic panel 103 are arranged. The loop heat pipe 2 is arranged from top to bottom as a loop heat pipe hot end 201, a loop heat pipe adiabatic section 202 and a loop heat pipe cold end 203.

[0037] The water storage tank 3 includes a water storage tank heat exchange part 301 and a water storage tank heat storage irrigation part 302, the water storage tank heat exchange part 301 exchanges heat with the loop heat pipe cold end 203, the water storage tank heat exchange part 301 is provided with a water inlet 303, the water inlet 303 is communicated with a water inlet pipe 304; a water outlet valve 5 between the water storage tank heat exchange part 301 and the water storage tank heat storage irrigation part 302, the water storage tank heat storage irrigation part 302 is composed of a heat storage water cavity 3021 and an irrigation water cavity 3022, and an irrigation water inlet 305 is additionally arranged, which is connected to a drip irrigation pipe 306, the other end of the drip irrigation pipe 306 is directed to the root of the crop 8; and a total water outlet 307 is arranged at the bottom of the water storage tank heat storage irrigation part 302, and a field ridge heat insulation soil layer 7 is arranged above the water storage tank heat storage irrigation part 302; humidity monitors 9 are arranged in the upper, middle and lower parts of the greenhouse.

[0038] The system is provided with an auxiliary heating device 6 placed in the heat storage water tank for auxiliary heating, which is photoelectric converted by the photovoltaic panel and serves as an energy source.

[0039] When the above technical solution works, the working method includes the following modes:

[0040] Trough type solar light tracking collector heat collection:

[0041] The trough type solar light tracking collector 1 is driven by the photovoltaic panel 103, the light tracking system 102 makes the sunlight directly incident and then concentrates and collects heat, the light is concentrated to the loop heat pipe hot end 201 to heat the phase change material therein to change from liquid state to gaseous state, the heat is transferred along the loop heat pipe adiabatic section 202 to the loop heat pipe cold end 203 with the phase change material as the carrier, and then heat exchange is carried out with the water storage tank heat exchange part 301 of the water storage tank 3, the water temperature rises; after heat exchange, the phase change material liquefies and returns to the loop heat pipe hot end 201 under the action of the wick, continues to heat, and so on, and the heat exchange is circulated.

[0042] The trough type solar heat collection system first provides electric energy by a solar power panel to drive the light tracking system 102 to adjust the angle of the parabolic trough reflector in real time, so that it is always aligned with the sun to achieve efficient light concentration. The concentrated sunlight heats the heat transfer medium in the heat collection pipe, and the high-temperature medium then flows through the heat storage unit, causing the phase change material inside to absorb heat and change from liquid to gas, storing a large amount of heat energy.

[0043] Loop heat pipe self-driving:

[0044] The heat energy collected by the trough type solar light tracking collector 1 is transferred from the hot end 201 of the loop heat pipe to the cold end 203 of the loop heat pipe, and the transfer process is driven by the temperature difference; after the hot end 201 of the loop heat pipe is heated, the high-temperature steam is automatically transferred to the cold end by the transfer part under the action of the temperature difference driving force between the hot end and the cold end.

[0045] Water injection and heating of the water storage tank:

[0046] The water inlet 303 is opened in advance to input cold water to the water storage tank heat exchange part 301 of the water storage tank 3, and the loop heat pipe cold end 203 is immersed in the water storage tank heat exchange part 301 for sufficient heat exchange, thereby realizing heat storage;

[0047] Water discharge and heat storage of the water storage tank:

[0048] The temperature monitor 4 monitors the opening of the water discharge valve 5 between the water storage tank heat exchange part 301 and the water storage tank heat storage irrigation part 302 when the temperature reaches the set temperature, so as to transfer the warm water to the entire water tank, that is, to transfer the heat to the water storage tank heat storage water cavity 3021, realize the overall uniform heat storage of the system, and maintain the stable temperature in the shed;

[0049] When the high-temperature gaseous phase change working medium enters the condensing end of the loop heat pipe, the internal steam and the condenser wall surface occur convective heat transfer, and the heat is transferred to the metal wall surface; the outer wall of the condenser transfers the heat to the heat exchange surface connected with the water storage tank, and then transfers the heat to the low-temperature water medium in the water tank through convective heat transfer. In this process, the high-temperature steam gradually condenses into liquid due to heat release, and returns to the evaporation end under the driving of capillary force, completing an efficient heat transfer cycle.

[0050] Water storage tank warm water irrigation:

[0051] When the temperature monitor 4 determines that the water temperature in the water storage tank is suitable for irrigation or the humidity monitor 9 monitors that the humidity in the shed is less than the threshold value, the irrigation water inlet 305 is opened to connect the irrigation water cavity 3022 with the drip irrigation pipe 306, and the crops 8 are subjected to directional drip irrigation.

[0052] That is, when the system detects that the temperature or humidity in the shed is below the set threshold, the control valve between the heat exchange unit and the irrigation system is automatically opened. The warm water flows through the distributed irrigation pipe network under the drive of the water pump, and uniformly releases heat to the shed through radiation and convection. This process effectively maintains the temperature stability of the greenhouse environment while improving the temperature of the irrigation water, achieving efficient recycling of heat energy.

[0053] The system comprises a trough type solar heat collector, a loop heat pipe, a water storage tank, a light tracking system, a solar power panel and a temperature detector.

[0054] The volume of the loop heat pipe and the water storage tank needs to be calculated according to local sunshine conditions, air temperature conditions and other factors, and the filling ratio of the phase change material can be adjusted according to the season.

[0055] The temperature detector can monitor the indoor temperature change in real time, facilitating the adjustment of the next process.

[0056] The loop heat pipe and water heat storage coupling system have the advantages of high heat storage density, high heat storage temperature, high heat storage and release efficiency, good diurnal continuity and fast response speed, can fully convert and store solar energy into medium and low temperature heat energy during the day, and provide a large amount of heat to the greenhouse shed for heating at night.

[0057] During the day when the sun is sufficient, solar energy is collected by the trough type heat collector, and the heat is efficiently transferred to the water tank by the loop heat pipe, and is insulated by the heat insulation layer, and the water in the water storage tank is used for long-time heat dissipation under the condition of no light at night, so as to provide a timely and stable heat source for the greenhouse. The loop heat pipe and water heat storage coupling system automatically realize the purpose of high efficiency heat storage during the day and continuous heat supply at night.

[0058] The above embodiments are only used to illustrate the present application, and any equivalent transformation and improvement based on the technical solutions of the present application should not be excluded from the protection scope of the present application.

Claims

1. A loop heat pipe and water storage thermal coupling system for greenhouses, characterized in that: The system includes a trough solar collector (1), a loop heat pipe (2), and a water storage tank (3); The trough-type solar collector (1) is provided with a collector trough (101), a light-tracing system (102) and a photovoltaic panel (103). The loop heat pipe (2) is configured from top to bottom as a hot end (201), an insulating section (202), and a cold end (203). The water storage tank (3) includes a heat exchange section (301) and a heat storage irrigation section (302). The heat exchange section (301) exchanges heat with the cold end (203) of the loop heat pipe. The heat exchange section (301) is provided with an inlet (303) and is connected to an inlet pipe (304). A drain valve (5) is provided between the heat exchange section (301) and the heat storage irrigation section (302). 02) It consists of a hot water storage chamber (3021) and an irrigation water chamber (3022), and is also provided with an irrigation water inlet (305), which is connected to a drip irrigation pipe (306). The other end of the drip irrigation pipe (306) is directed to the roots of the crop (8). A total drain outlet (307) is provided at the bottom of the heat storage irrigation part (302) of the water storage tank. A field ridge heat insulation soil layer (7) is provided above the heat storage irrigation part (302) of the water storage tank. Humidity monitoring instruments (9) are provided in the upper, middle and lower parts of the greenhouse.

2. The loop heat pipe and water storage heat coupling system for greenhouses according to claim 1, characterized in that, The system is equipped with an auxiliary heating device (6), which is placed in a hot water storage tank for auxiliary heating. The photovoltaic panel performs photoelectric conversion and serves as the energy source.

3. The working method of a loop heat pipe and water storage heat coupling system for a greenhouse according to claim 1 or 2, characterized in that, Includes the following modes: Parabolic trough solar collectors collect heat: The trough-type solar collector (1) is powered by photovoltaic panels (103). The tracking system (102) allows sunlight to be directly incident and thus concentrates the light to collect heat. The light is concentrated to the hot end (201) of the loop heat pipe, heating the phase change material inside and causing it to change from liquid to gas. The heat is transferred along the insulating section (202) of the loop heat pipe to the cold end (203) of the loop heat pipe, using the phase change material as a carrier. Then, it exchanges heat with the heat exchange section (301) of the water tank (3), and the water temperature rises. After the heat exchange, the phase change material liquefies and returns to the hot end (201) of the loop heat pipe under the action of the liquid wick, and continues to be heated. This process is repeated to circulate the heat exchange. Loop heat pipe self-driving: The heat energy collected by the trough solar collector (1) is transferred from the hot end (201) of the loop heat pipe to the cold end (203) of the loop heat pipe, and the transfer process is driven by the temperature difference. Water tank filling and heating: Cold water is input into the heat exchange section (301) of the water storage tank (3) by opening the inlet (303) in advance. The cold end (203) of the loop heat pipe is immersed in the heat exchange section (301) of the water storage tank for full heat exchange, thereby realizing the storage of heat. Water storage tank for heat storage: After the temperature monitoring instrument (4) monitors that the set temperature is reached, it opens the drain valve (5) between the heat exchange part (301) of the water storage tank and the heat storage irrigation part (302) of the water storage tank, thereby transferring the warm water to the entire water tank, that is, transferring the heat to the heat storage chamber (3021) of the water storage tank, realizing the overall uniform temperature storage of the system, and maintaining the stable temperature inside the greenhouse. Warm water irrigation from storage tank: Temperature monitor (4) determines that the water temperature in the water tank is suitable for irrigation or humidity monitor (9) detects that the humidity in the greenhouse is less than the threshold, and opens the irrigation water inlet (305) to connect the irrigation water chamber (3022) with the drip irrigation pipe (306) to carry out targeted drip irrigation on the crop (8).

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