Greenhouse energy storage device and method for adjusting temperature of greenhouse

Abstract

The invention discloses a greenhouse energy storage device which is provided with a water tank and a circulating heat exchange unit. The water tank can absorb external heat, water in the water tank circulates out, and air and water are subjected to heat exchange, heat storage or heat release through air convection. Peak shifting and valley filling of the temperature in the greenhouse are achieved, and plants are made to be in a proper temperature interval. The energy storage device is easy to install, low in cost, obvious in temperature adjustment and capable of meeting the use requirements of people.

Description

Technical Field

[0001] The invention relates to the technical field of agricultural greenhouses, and in particular to an energy storage device for storing and releasing heat in a greenhouse and a method for regulating the temperature of the greenhouse. Background Art

[0002] Greenhouses can let in light and increase the environmental temperature of crops. In seasons that are not suitable for plant growth, greenhouses can be used to grow vegetables, flowers, and raise seedlings. They are widely used in the agricultural field in my country.

[0003] At present, most greenhouses in use use simple plastic film and skeleton structures. In winter, the temperature difference between day and night is large, the temperature during the day is too high, and the temperature in the greenhouse at noon is higher than 33°C. The photosynthesis of crops stops, photorespiration is enhanced, and photosynthesis weakens. This results in a decrease in crop yields. At the same time, high temperatures promote water evaporation, and the humidity in the greenhouse increases, increasing the risk of crop diseases. The solution is to open the greenhouse at noon to cool down and dehumidify, but this will waste precious solar energy. At night or in extremely cold weather, the temperature in the greenhouse is low. When the temperature in the greenhouse is lower than the optimal temperature for vegetable growth for a long time, the growth and development of crops will be hindered or even frozen to death. Additional heating equipment is required. In addition to the increase in operating costs, "carbon emissions" are also increased.

[0004] Therefore, installing energy storage devices in greenhouses has become a development focus. It can store excess heat in the air during the day and dissipate it indoors when the indoor temperature is lower at night, playing the role of "shifting peaks and filling valleys". It can regulate the temperature in the greenhouse, give plants a more suitable temperature and humidity, increase crop yields, and reduce carbon emissions.

[0005] However, the energy storage devices currently used generally have problems such as weak temperature regulation ability, complex equipment, high cost, and heavy burden on farmers. Therefore, at present, it is still necessary to develop an energy storage device for greenhouse temperature regulation that can effectively regulate temperature, achieve peak shifting and valley filling, has a simple device, is easy to install, and has a low cost to meet people's needs. Summary of the invention

[0006] In order to solve the above problems, the present invention provides a greenhouse energy storage device, which is provided with a water tank and a circulating heat exchange unit. When the outside temperature is high, on the one hand, the water tank can absorb the heat from the outside, and on the other hand, the water in the water tank is circulated out, and a convection device is used to exchange the heat in the air into the water tank, so that the ambient temperature is reduced and the heat is stored. When the outside temperature is reduced, the water in the water tank is circulated out, and the temperature in the greenhouse is increased by convection. Thereby, the temperature in the greenhouse is shifted and the valley is filled, so that the plants are in a suitable temperature range. In addition, the energy storage device in the present invention is simple to install, low in cost, and has obvious temperature regulation, which can meet the use requirements of the greenhouse.

[0007] The object of the present invention is to provide a greenhouse energy storage device, the device comprising a water tank, a heat exchange unit and a circulation pipeline, the water tank body is transparent, and a heat exchange liquid medium is passed into the water tank. The heat exchange liquid medium contains water.

[0008] A partition is arranged inside the water tank, and the interior of the partition is filled with phase change material and / or photothermal material.

[0009] The water tank is connected with the heat exchange unit through a circulation pipeline.

[0010] The heat exchange unit is provided with a plurality of cooling pipes.

[0011] The fan is arranged above or below the cooling pipe to form a downward airflow of the air in the greenhouse.

[0012] The present invention also aims to provide a method for adjusting the temperature of a greenhouse by using the greenhouse energy storage device. The method arranges the greenhouse energy storage device in the greenhouse.

[0013] The present invention has the following beneficial effects:

[0014] (1) The greenhouse energy storage device of the present invention uses water as the heat absorbing and releasing energy storage medium, which is easy to obtain and low in cost, thus greatly reducing the cost of the greenhouse.

[0015] (2) The present invention uses a transparent water tank to store heat exchange liquid medium, which directly receives heat from the sun and the greenhouse, and can absorb heat faster, store heat, and reduce the temperature in the greenhouse.

[0016] (3) The present invention also provides a heat exchange unit to exchange the heat exchange liquid medium and form convection with the air to further promote heat exchange. When the temperature is high, it absorbs heat, and when the temperature is low, it releases heat, so that the temperature in the greenhouse is maintained within a temperature range suitable for crop growth.

[0017] (4) The greenhouse energy storage device of the present invention has a simple structure, is easy to install and use in the greenhouse, is convenient to construct, has a simple structure, and is low in cost, and is suitable for promotion and application in actual greenhouses. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A schematic diagram showing the structure of the greenhouse energy storage device of the present invention is shown;

[0019] Figure 2 The temperature variation curves of the experimental greenhouse and the control greenhouse in Example 1 of the present invention are shown;

[0020] Figure 3 The humidity change curves of the experimental greenhouse and the control greenhouse in Example 1 of the present invention are shown;

[0021] Figure 4 The temperature change curves of the experimental greenhouse and the control greenhouse under three consecutive days of rainy and snowy weather in Example 2 of the present invention are shown;

[0022] Figure 5 The temperature variation curves of the experimental greenhouse and the control greenhouse under normal weather conditions in Example 2 of the present invention are shown.

[0023] Description of Figure Numbers

[0024] 1- Water tank;

[0025] 101-partition;

[0026] 2-Heat exchange unit;

[0027] 201-phase change material tube;

[0028] 202- cooling pipe;

[0029] 203- fan;

[0030] 204-fixed plate;

[0031] 3-Circulation pipeline;

[0032] 301-water circulation pipe;

[0033] 302-water inlet circulation pipe;

[0034] 303-Water pump. DETAILED DESCRIPTION

[0035] The present invention will be further described in detail below through the accompanying drawings and embodiments. Through these descriptions, the characteristics and advantages of the present invention will become more clear and distinct.

[0036] The present invention provides a greenhouse energy storage device, which includes a water tank 1, a heat exchange unit 2 and a circulation pipeline 3. Figure 1 shown.

[0037] The water tank 1 is transparent, and a heat exchange liquid medium is passed into the water tank 1, which can directly receive external sunlight, absorb heat, and achieve energy storage. The heat exchange liquid medium contains water. Through experiments, it is found that directly absorbing radiant heat is a very effective way of energy storage. The water tank 1 is a transparent container that can directly absorb the radiant heat of the sun, because the combined frequency and frequency doubling of the vibration of water molecules can well absorb the near-infrared radiant heat of sunlight, which plays a role in cooling the greenhouse.

[0038] In one embodiment of the present invention, the heat exchange liquid medium further comprises a black additive, selected from one or more of black dye, ink and graphene, preferably ink. Adding the black additive to the heat exchange liquid medium makes the water appear black, which can increase the heat absorption of the water in the water tank 1. Among them, ink has good dispersibility, can be evenly dispersed in the water for a long time, and has low cost.

[0039] In another embodiment of the present invention, aquatic cultured organisms, such as fish, shellfish, etc., preferably fish, are added to the water tank 1. While achieving energy storage, the water tank 1 is fully utilized, the utilization rate of the greenhouse is improved, and the income of farmers is increased. Moreover, the fish swimming in the water tank can also promote the flow of water in the water tank 1.

[0040] In a preferred embodiment of the present invention, a partition 101 is provided inside the water tank 1, and a phase change material and / or a photothermal substance is filled inside the partition 101. For example, the phase change material is polyethylene glycol, and the photothermal substance is black high-density polyethylene.

[0041] The partition 101 maintains a distance from the inner wall of the box. When the heat exchange liquid medium inside the box circulates in and out of the water tank 1, convection of the internal liquid medium can be formed due to the obstruction of the partition 101, which promotes mixing and enhances the exchange and absorption of internal heat.

[0042] The water tank 1 is connected to the heat exchange unit 2 through a circulation pipeline 3. The circulation pipeline 3 includes an outlet circulation pipe 301 and an inlet circulation pipe 302. The water outlet of the water tank 1 is connected to the water inlet of the heat exchange unit 2 through the outlet circulation pipe 301, and the water inlet of the water tank 1 is connected to the water outlet of the heat exchange unit 2 through the inlet circulation pipe 302. A water pump 303 is provided on the outlet circulation pipe 301 or the inlet circulation pipe 302 to circulate the heat exchange liquid medium. When the heat exchange liquid medium flows inside the outlet circulation pipe 301 and the inlet circulation pipe 302, it can also exchange heat with the air inside the greenhouse.

[0043] The heat exchange unit 2 is provided with a plurality of cooling tubes 202, and the cooling tubes 202 are connected by pipelines, and the heat exchange liquid medium enters each cooling tube 202 through the outlet circulation tube 301, and then circulates back to the water tank 1 through the inlet circulation tube 302. The fan 203 is arranged above or below the adjacent cooling tube 202, so that the air in the greenhouse forms a downward airflow, so that the air and the cooling tube 202 perform heat exchange.

[0044] The heat exchange unit 2 is further provided with a plurality of phase change material tubes 201, forming an array, which are arranged in the air outlet direction of the fan 203, and the fan 203 is used to complete heat exchange between air and the phase change material inside the phase change material tube 201. Preferably, the phase change material tube 201 is fixed by a fixing plate 204.

[0045] When the temperature inside the greenhouse rises, the heat exchange liquid medium enters the cooling pipe 202, absorbs the heat of the convective air, and reduces the temperature of the airflow. At the same time, the water tank 1, the water outlet circulation pipe 301, and the water outlet circulation pipe 301 can also absorb the heat inside the greenhouse and the direct sunlight to store energy, and jointly reduce the temperature inside the greenhouse. In addition, the fan 203 also makes the air exchange heat with the phase change material pipe 201 to absorb heat.

[0046] When the temperature inside the greenhouse drops, the heat exchange liquid medium enters the cooling tube 202 and the phase change material tube 201 to release the stored heat into the air. After convection between the air and the cooling tube, the air absorbs the heat and increases the temperature inside the greenhouse.

[0047] The present invention also provides a method for regulating the temperature of a greenhouse using the greenhouse energy storage device. The method arranges the greenhouse energy storage device in the greenhouse, preferably, the greenhouse energy storage device is arranged on the inner side of the north wall or west wall of the greenhouse, such as the inner side of the north wall.

[0048] The greenhouse energy storage device provided by the present invention uses cheap and easily available water as a heat exchange liquid medium, which is energy-saving and environmentally friendly, low-cost, easy to obtain, and fast in absorbing heat, and can conveniently and quickly realize energy storage, thereby reducing the economic burden on farmers. In addition, the energy storage device in the present invention utilizes a heat exchange unit to perform cyclic absorption and release of heat, thereby realizing peak shifting and valley filling of the greenhouse temperature, so that the crops are in a suitable temperature range, and preventing the influence of excessively high or low temperatures on plant crops.

[0049] Example

[0050] The present invention is further described below through specific examples, but these examples are merely exemplary and do not constitute any limitation to the scope of protection of the present invention.

[0051] Example 1

[0052] A temperature regulation experiment was conducted in a greenhouse in Beijing during winter. The greenhouse was separated in the middle to form two independent greenhouses. The greenhouse energy storage device provided by the present invention was placed on the north wall of one of the greenhouses (experimental greenhouse); the other greenhouse was not placed with an energy storage device (control greenhouse). The two greenhouses each occupied an area of ​​120m 2 The highest point is 5m.

[0053] The device is provided with a water tank 1 (without the heat exchange unit 2 and the circulation pipeline 3), and its size is 3 boxes with a length of 4m×width of 0.7m×height of 1.5m. The water tank 1 uses a transparent plastic film as the water tank wall, and is filled with tap water.

[0054] The temperature changes were continuously recorded for five days (from 1:00 a.m. on December 27 to 10:00 p.m. on December 31). The temperature inside the two greenhouses was recorded every three hours. The temperature change curve is as follows: Figure 2 As shown. Figure 2 It can be seen that adding a greenhouse energy storage device can reduce the maximum temperature in the greenhouse by 4°C at noon and increase the minimum temperature at night by 2-3°C.

[0055] The humidity was continuously recorded from noon to midnight from December 17 to December 31. The humidity change curve is as follows: Figure 3 As shown. Figure 3 It can be seen that the greenhouse energy storage device can significantly reduce the humidity at noon and increase the humidity at night.

[0056] Example 2

[0057] The temperature regulation experiment was carried out in the same control greenhouse and experimental greenhouse as in Example 1. The device is provided with a water tank 1 , a heat exchange unit 2 and a circulation pipeline 3 .

[0058] The water tank 1 uses a transparent plastic film as the water tank wall, and is filled with tap water. The dimensions are 3 boxes with a length of 4m, a width of 0.7m, and a height of 1.5m. A partition 101 filled with a phase change material (polyethylene glycol) and a photothermal material (black high-density polyethylene) is provided, and the dimensions of the partition 101 are 3.5m long, 0.05m wide, and 1m high.

[0059] A water pump 303 is provided on the outlet water circulation pipe 301. In the heat exchange unit 2, a cooling pipe 202 is provided on the top, and a fan 203 is provided near the bottom thereof to form a downward air flow, which is blown into the array of phase change energy storage tubes 201 below the fan 203.

[0060] The length of the outlet circulation pipe 301 and the inlet circulation pipe 302 are both 5m, and the internal water circulation flow rate is 2m 3 / h, the total amount of water in the cooling pipe 201 is 10L.

[0061] The temperature of the experimental greenhouse and the control greenhouse was measured continuously from 1:00 a.m. on January 11 to 22:00 p.m. on January 13. The temperature change curve is as follows: Figure 4 From January 11 to January 13, it was cloudy, rainy and snowy for three consecutive days.

[0062] from Figure 4 It can be seen that in the absence of sunlight, the experimental greenhouse equipped with an energy storage device can maintain the temperature inside the greenhouse to a certain extent.

[0063] The temperature changes of the two greenhouses were measured on January 23 under normal weather conditions (external ambient temperature was -3 to -14°C). The temperature change curve is as follows: Figure 5 As shown. Figure 5It can be seen that when the external temperature is -3 to -14℃, the temperature in the experimental greenhouse can still increase by 1-3℃ at night and up to 3.8℃ during the day compared with the control greenhouse.

[0064] The present invention is described in detail above in conjunction with specific embodiments and / or exemplary examples and drawings, but these descriptions cannot be understood as limiting the present invention. Those skilled in the art understand that, without departing from the spirit and scope of the present invention, various equivalent substitutions, modifications or improvements may be made to the technical solutions and implementations of the present invention, all of which fall within the scope of the present invention. The scope of protection of the present invention shall be subject to the attached claims.

Claims

1. A greenhouse energy storage device, comprising a water tank (1), a heat exchange unit (2) and a circulation pipeline (3), wherein the water tank (1) has a transparent body and a heat exchange liquid medium is passed into the water tank (1).

2. The device according to claim 1, characterized in that The heat exchange liquid medium comprises water.

3. The device according to claim 1, characterized in that The heat exchange liquid medium further comprises a black additive, which is selected from one or more of black dye, ink and graphene, preferably ink.

4. The device according to claim 1, characterized in that A partition (101) is arranged inside the water tank (1), and the interior of the partition (101) is filled with phase change material and / or photothermal material, and the partition (101) maintains a distance from the inner wall of the tank.

5. The device according to claim 4, characterized in that The phase change material is polyethylene glycol, and the photothermal material is black high-density polyethylene.

6. The device according to claim 1, characterized in that The water tank (1) is connected to the heat exchange unit (2) via a circulation pipeline (3). The water outlet of the water tank (1) is connected to the water inlet of the heat exchange unit (2) through the water outlet circulation pipe (301), and the water inlet of the water tank (1) is connected to the water outlet of the heat exchange unit (2) through the water inlet circulation pipe (302). A water pump (303) is provided on the water outlet circulation pipe (301) or the water inlet circulation pipe (302) to circulate the heat exchange liquid medium.

7. The device according to claim 1, characterized in that The heat exchange unit (2) is provided with a plurality of cooling pipes (202). The cooling pipes (202) are connected via pipelines. The heat exchange liquid medium enters each cooling tube (202) through the water outlet circulation pipe (301), and then circulates back to the water tank (1) through the water inlet circulation pipe (302).

8. The device according to claim 1, characterized in that The fan (203) is arranged above or below the cooling pipe (202) to form a downward airflow for the air in the greenhouse, so that the air and the cooling pipe (202) can exchange heat. The heat exchange unit (2) is further provided with a plurality of phase change material tubes (201) to form an array, which is arranged in the air outlet direction of the fan (203), and utilizes the fan (203) to complete heat exchange between air and the phase change material inside the phase change material tubes (201).

9. The device according to claim 2, characterized in that Aquatic culture organisms are added into the water tank (1), selected from fish and / or shellfish, preferably fish.

10. A method for regulating the temperature of a greenhouse using the greenhouse energy storage device according to any one of claims 1 to 9, characterized in that: The method is to place the greenhouse energy storage device in the greenhouse. Preferably, the greenhouse energy storage device is arranged on the inner side of the north wall or west wall of the greenhouse, such as the inner side of the north wall.

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