A solar heat storage device for a greenhouse

Abstract

The present application relates to the technical field of agricultural production, in particular to a solar heat storage device for greenhouse. The temperature of traditional greenhouse mostly lacks heat storage means, and it is difficult to maintain the greenhouse temperature for a long time. The technical scheme of the present application comprises a heat preservation bin buried underground, and a circulating heat storage system formed by a series connection of a sunshine preheating cavity, a solar light condensing collector, a heat storage device and a circulating pump, and the heat storage device is arranged in the heat preservation bin; water is used as heat storage medium, and after being heated twice by the sunshine preheating cavity and the solar light condensing collector, the water is stored in the heat storage device for heat preservation, and when the greenhouse temperature drops, the water releases heat to provide heat source for the greenhouse. The present application is suitable for agricultural production of greenhouse in low temperature season, and heat is absorbed by the circulating heat storage system and stored in the underground through the heat storage medium, and the greenhouse can be heated for a long time.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of agricultural production, in particular to a solar heat storage device for a greenhouse. BACKGROUND

[0002] Greenhouse is an important facility in agricultural production, and its structure is mostly supported by a framework and covered with a plastic shed film to form a well-lit and heat-insulating space. In low-temperature seasons, it provides a suitable environment temperature for the growth of plants and animals. The temperature inside the traditional greenhouse mostly depends on solar radiation and relative sealing of the space, that is, the temperature in the shed is closely related to the sunlight. Insufficient sunlight will cause the shed temperature to drop rapidly and significantly, making it difficult to maintain a constant temperature, which is extremely detrimental to the growth of crops. In particular, in most northern regions of China, the climate in spring and winter often causes large diurnal temperature differences, short sunlight duration, difficulty in maintaining a constant shed temperature, and low irrigation water temperature, which seriously affects the normal growth of crops. In the event of sudden weather changes, the low shed temperature may even cause crop frost damage, causing significant economic losses to the growers.

[0003] To address the above problems, some growers in certain regions choose to burn fires inside the greenhouse to raise the temperature in the shed. This approach not only increases the cost of planting, but also poses a significant safety hazard and has some impact on the environment. In addition, some farmers use solar power generation (heat) in combination with a greenhouse to raise the temperature in the shed. However, due to the lack of heat storage means, the problem of insufficient sunlight and low temperature still cannot be completely solved, and the large-scale laying of solar panels and other components on the roof of the greenhouse to some extent affects the light absorption of crops. SUMMARY

[0004] The purpose of the present application is to provide a solar heat storage device for a greenhouse, which is suitable for agricultural production in a greenhouse in low-temperature seasons, uses a circulating heat storage system to absorb heat and store it underground, and releases heat to provide a heat source for the greenhouse when the shed temperature drops.

[0005] The technical solution of the present application includes a solar preheating chamber, a solar concentrator, a heat-insulating warehouse, a heat storage device, and a circulating pump.

[0006] The heat-insulating warehouse is buried in the ground of the greenhouse, and the heat storage device is arranged in the warehouse. The space between the outer wall of the heat storage device and the inner wall of the heat-insulating warehouse forms a heat storage chamber.

[0007] The upper section or top of the heat storage device is provided with an air inlet and an air outlet, and the air inlet and the air outlet are both equipped with dampers.

[0008] The heat-insulating warehouse is provided with a heat dissipation port and a supplementary air inlet, both of which are in communication with the greenhouse. The heat-insulating warehouse is provided with a fan, which discharges heat to the greenhouse through the heat dissipation port.

[0009] The sunlight preheating cavity is a transparent water storage container and is arranged above the greenhouse.

[0010] The lower part of the heat accumulator is connected with the upper part of the sunlight preheating cavity through an upgoing water pipe, the lower part of the sunlight preheating cavity is connected with the upper part of the heat accumulator through a downgoing water pipe, the circulating pump is connected in series on the upgoing water pipe, the solar light collecting heat collector is connected in series on the downgoing water pipe, and a water inlet valve is installed on the downgoing water pipe between the solar light collecting heat collector and the heat accumulator.

[0011] Further, the warehouse wall of the heat preservation warehouse is composed of a waterproof layer, a heat insulation layer and a permeable heat storage layer from outside to inside.

[0012] Further, the heat preservation warehouse is provided with at least one inspection well.

[0013] Further, the air supplementing port and / or the heat dissipating port of the heat preservation warehouse is provided with a ventilation valve.

[0014] Further, the structure of the sunlight preheating cavity is a strip-shaped cavity, a long groove or a water bag.

[0015] Further, the sunlight preheating cavity is connected with an external water supplementing mechanism, and the lower part of the sunlight preheating cavity is provided with a water outlet.

[0016] Further, the sunlight preheating cavity is provided with a liquid level limiting mechanism.

[0017] Further, the heat accumulator is provided with a liquid level meter and a water temperature meter for monitoring the water storage amount and temperature.

[0018] Further, the solar light collecting heat collector is arranged on the ground outside the greenhouse.

[0019] The beneficial effect of the present application is: using the heat energy of solar radiation, using water as a heat storage medium, when the temperature is higher in the daytime, the heat storage medium is heated by the circulating heat storage system composed of the sunlight preheating cavity, the solar light collector, the heat storage device, etc. in batches, and is stored in the underground for a long time; the water in the sunlight preheating cavity is preheated by sunlight, and then flows downward through the solar light collector to be heated again, which effectively improves the heating efficiency; the high-temperature water flows into the heat storage device to replace the low-temperature water in the heat storage device, and then is pumped into the sunlight preheating cavity to enter the next heating cycle until the water temperature in the heat storage device meets the requirements. When it is night or the temperature decreases, the heat can be slowly released into the greenhouse through the heat preservation bin and the heat storage device according to the actual situation to maintain the temperature in the greenhouse, ensure the agricultural production, save energy and be conducive to environmental protection. Since the device heats the circulating water in batches, and the water temperature (preheated water) in the sunlight preheating cavity is roughly the same as the greenhouse temperature after the circulating heat exchange is stopped, the water can be directly used for crop irrigation or mixed with cold water to solve the problem of slow growth of crops caused by cold water irrigation in low-temperature seasons.

[0020] In addition, the sunlight preheating cavity is made of transparent material, and the solar light collector can be flexibly arranged according to the situation (such as on the ground between two greenhouses), so as to avoid blocking sunlight and affecting crop growth.

[0021] The technical solutions of the present application will be described in detail below in combination with the drawings and specific embodiments. DRAWINGS

[0022] Figure 1 is a structural schematic diagram of the present application;

[0023] Figure 2 is a side view schematic diagram of Figure 1 . DETAILED DESCRIPTION

[0024] In the figure: 1-greenhouse, 2-sunlight preheating cavity, 3-water supplementing mechanism, 4-drainage port, 5-radiator, 6-water inlet valve, 7-air inlet, 8-solar light collector, 9-heat storage device, 9a-air inlet, 9b-air outlet, 10-heat preservation bin, 10a-waterproof layer, 10b-thermal insulation layer, 10c-permeable heat storage layer, 11-circulating pump, 12-inspection well, 13-radiator port. EMBODIMENT

[0025] The equipment, elements and materials used in the heat storage device of the present application are all conventional products on the market.

[0026] As can be seen from Figures 1-2 , the technical solutions of the present application include a sunlight preheating cavity 2, a solar light collector 8, a heat preservation bin 10, a heat storage device 9 and a circulating pump 11;

[0027] The heat preservation bin 10 is buried below the ground freezing line of the greenhouse 1, the bin wall of the heat preservation bin 10 is composed of three layers, and from outside to inside, the three layers are a waterproof layer 10a, a heat insulation layer 10b and a permeable heat storage layer 10c; the waterproof layer 10a on the surface can effectively prevent the internal infiltration of water in the soil, the heat insulation layer 10b in the middle can be made of polyurethane or asbestos material to prevent heat loss in the bin, and the permeable heat storage layer 10c on the inside is made of sand-free cement and the like to play a role of heat storage and support.

[0028] The heat storage device 9 is installed in the heat preservation bin 10, and a heat storage cavity is formed between the outer wall of the heat storage device 9 and the permeable heat storage layer of the inner wall of the heat preservation bin 10.

[0029] The heat preservation bin 10 is provided with a heat dissipation port 13 and an air supplement port 7, and the heat dissipation port and the air supplement port are communicated with the greenhouse 1; the air supplement port 7 and / or the heat dissipation port 13 are installed with a ventilation valve; the heat preservation bin is installed with at least one fan to extract the heat in the bin and send it to the greenhouse.

[0030] The solar preheating cavity 2 is a transparent water storage cavity, and the solar preheating cavity 2 is arranged above the greenhouse 1 and is fixedly connected with the support frame of the greenhouse. The water storage cavity is made of transparent material (such as acrylic), so as to avoid blocking sunlight. According to actual needs, the solar preheating cavity can be made into a strip-shaped tank, a long groove body or a water bag.

[0031] The lower section or bottom of the heat storage device 9 is connected with the upper section or top of the solar preheating cavity 2 through an upward water pipe, and the lower section or bottom of the solar preheating cavity 2 is connected with the upper section or top of the heat storage device 9 through a downward water pipe; the circulating pump 11 is connected in series on the upward water pipe, the solar light condensing collector 8 is connected in series on the downward water pipe, and a water inlet valve 6 is installed on the downward water pipe between the solar light condensing collector 8 and the heat storage device 9, that is, the solar preheating cavity 2, the solar light condensing collector 8, the water inlet valve 6, the heat storage device 9 and the circulating pump 11 are connected in series to form a circulating heat storage system.

[0032] In order to facilitate the operation and maintenance of the underground equipment, the heat preservation bin should be provided with at least one inspection well. In the embodiment, one inspection well 12 is arranged at each end of the heat preservation bin, the heat dissipation port 13 of the heat preservation bin is arranged at the top of the inspection well on the upward water pipe side, and a fan is installed on the heat dissipation port 13. A strip-shaped radiator can be arranged at a proper position in the greenhouse 1, and the radiator is connected with the heat dissipation port 13 through a wind pipe, and the radiator is used to uniformly discharge heat into the greenhouse through the nozzle; the air supplement port 7 is arranged at the top of the inspection well on the downward water pipe side; the air supplement port 7 is installed with a ventilation valve, such as a butterfly baffle or a one-way check valve, and the ventilation valve can be opened by a motor or manually.

[0033] The upper section or top of the heat accumulator 9 is provided with an air inlet 9a and an air outlet 9b, the air inlet 9a is located at the air supplementing port side of the heat preservation bin 10, and the air outlet 9b is located at the heat dissipation port side of the heat preservation bin, and air doors are installed on the air inlet 9a and the air outlet 9b, and the air doors can be controlled by a motor, and the air doors are closed in the heat storage state and opened in the heat dissipation state.

[0034] In the embodiment, the sunlight preheating cavity 2 is connected with an external water supplementing mechanism 3, and a liquid level limiting mechanism is installed in the sunlight preheating cavity 2, for example, a conventional water level meter is selected to cooperate with an electromagnetic water valve of the water supplementing mechanism, or a float type water inlet valve is used to control the water amount in the preheating cavity; a water outlet 4 is arranged at the lower part of the sunlight preheating cavity.

[0035] The heat accumulator 9 is provided with a liquid level meter and a water temperature meter, which are used to monitor the water storage amount and the water temperature of the heat accumulator, and can prompt the water storage condition in the heat accumulator at any time, and the liquid level meter and the water temperature meter can be connected and coordinated with the circulating pump 11 and the water inlet valve 6 to control the liquid level height to be lower than the air inlets 9a or the air outlets 9b of the heat accumulator, so as to ensure that there is enough air storage in the upper section of the heat accumulator.

[0036] The solar light concentrating collector 8 is arranged on the ground outside the greenhouse, so as not to occupy the space in the greenhouse and not to block sunlight. The solar light concentrating collector can be a groove-shaped parabolic light concentrating collector, a rotary parabolic light concentrating collector, a linear Fresnel reflection light concentrating collector or a plane reflection central tower type light concentrating collector, or a plurality of sets of light concentrating collectors can be used in combination to achieve better heating effect.

[0037] The device is used for heat storage and heat preservation of the greenhouse in low temperature seasons, and the elements such as the circulating pump, the water inlet valve, the fan and the ventilation valve of the heat preservation bin and the air door of the heat accumulator can be controlled by a conventional electric control system or a PLC controller to automatically coordinate the work, or manually operated.

[0038] When the sunlight is sufficient and the air temperature is relatively high at noon in the daytime in low temperature seasons, the water remaining in the sunlight preheating cavity 2 is heated by the sunlight, or when the water temperature in the underground heat accumulator 9 is monitored to be relatively low at this time, the circulating pump 11 is started to pump the low temperature water in the heat accumulator 9 to the sunlight preheating cavity 2 along the upward water pipe; at the same time, the water inlet valve 6 is opened, the water in the sunlight preheating cavity which has been preliminarily heated flows out along the downward water pipe, is heated again when flowing through the solar light concentrating collector 8, and finally enters the heat accumulator 9. The above-mentioned circulation is repeatedly performed, and after the water temperature in the heat accumulator 9 is overall increased, the circulating pump 11 is stopped, and the water inlet valve 6 is closed, so as to store the high temperature water in the heat accumulator. At this time, the air doors of the air inlets and outlets of the heat accumulator 9, the heat dissipation port and / or the air supplementing port of the heat preservation bin 10 are all in the closed state. The heat or excess heat radiated from the heat accumulator is stored in the heat storage cavity (the interlayer between the heat accumulator and the heat preservation bin 10) and the permeable heat storage layer.

[0039] When the temperature in the greenhouse is decreased at night or when the weather changes, the fan, the heat dissipation port and the air inlet of the heat preservation bin are opened, and the hot air in the heat storage cavity is sent into the greenhouse through the radiator 5. When the temperature in the heat storage cavity gradually decreases or further decreases, the air inlet and the air outlet of the heat accumulator are opened, and the heat in the heat accumulator is sent into the greenhouse through the heat storage cavity and the radiator. Because the underground temperature is higher than the ground temperature, the temperature in the heat storage cavity and the heat accumulator decreases slowly, and the heat can be provided to the greenhouse for a long time to maintain the temperature in the greenhouse. When the temperature rises in the daytime, the circulating heat storage system is started again to absorb heat and store energy.

[0040] In addition, another advantage of the device is that the water in the circulating heat storage system is heated twice. When the water temperature in the heat accumulator meets the requirements, the circulating heat exchange can be stopped, and the water preheated in the sunlight preheating cavity has a relatively low temperature. The water can be directly used for irrigation of crops or mixed with cold water, which effectively solves the problem of cold water irrigation affecting the growth of crops in the low temperature season.

[0041] The above detailed description of the technical solutions of the present application by means of the preferred embodiments is illustrative rather than formal limitation. Based on the description of the present application, those skilled in the art can modify the technical solutions recorded in the embodiments or replace some of the technical features with equivalent ones, and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A solar heat storage device for a greenhouse, characterized by: It comprises a sunlight preheating chamber (2), a solar light collector (8), a heat preservation bin (10), a heat accumulator (9) and a circulating pump (11). The heat preservation bin (10) is buried in the ground of the greenhouse (1), the heat accumulator (9) is arranged in the heat preservation bin (10), and a heat storage cavity is formed between the outer wall of the heat accumulator (9) and the inner wall of the heat preservation bin (10). The upper section or top of the heat accumulator (9) is provided with an air inlet (9a) and an air outlet (9b), and the air inlet (9a) and the air outlet (9b) are both provided with dampers. The heat preservation bin (10) is provided with a heat dissipation port (13) and a supplementary air inlet (7), and the heat dissipation port (13) and the supplementary air inlet (7) are both communicated with the greenhouse (1); the heat preservation bin (10) is provided with a fan, and the fan discharges heat to the greenhouse through the heat dissipation port. The sunlight preheating chamber (2) is a transparent water storage container and is arranged above the greenhouse (1); the sunlight preheating chamber (2) is connected with an external water supplementing mechanism (3), and the lower part of the sunlight preheating chamber is provided with a water outlet (4). The lower part of the heat accumulator (9) is connected with the upper part of the sunlight preheating chamber (2) through an upward water pipe, and the lower part of the sunlight preheating chamber (2) is connected with the upper part of the heat accumulator (9) through a downward water pipe; the heat accumulator (9) is provided with a liquid level meter and a water temperature meter for monitoring the water storage capacity and temperature. The circulating pump (11) is connected in series on the upward water pipe, the solar light collector (8) is connected in series on the downward water pipe, and a water inlet valve (6) is arranged on the downward water pipe between the solar light collector (8) and the heat accumulator (9).

2. The solar heat storage device for a greenhouse according to claim 1, characterized in that: The bin wall of the heat preservation bin (10) is composed of a waterproof layer (10a), a heat insulation layer (10b) and a permeable heat storage layer (10c) from outside to inside.

3. The solar heat storage device for a greenhouse according to claim 1, characterized in that: The heat preservation bin (10) is provided with at least one inspection well (12).

4. The solar heat storage device for a greenhouse according to claim 1, characterized in that: The supplementary air inlet (7) and / or the heat dissipation port (13) of the heat preservation bin (10) are provided with a ventilation valve.

5. The solar heat storage device for a greenhouse according to claim 1, characterized in that: The sunlight preheating chamber (2) has a structure of a strip-shaped cavity, a long groove or a water bag.

6. The solar heat storage device for a greenhouse according to claim 1, characterized in that: The sunlight preheating chamber (2) is provided with a liquid level limiting mechanism.

7. The solar heat storage device for a greenhouse according to any one of claims 1 to 6, characterized in that: The solar light collector (8) is arranged on the ground outside the greenhouse (1).

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