Temperature control system for plant growth

Abstract

To provide a temperature control system that enhances the growth of an expanded range of plant species.SOLUTION: A temperature control system 1 comprises one or more long growth beds 10A to C that receive a culture medium 3, and temperature control panels 20A to B having a pair of main walls 31, 32 that are opposed to each other in the thickness direction thereof. The pair of main walls 31, 32 define a heating medium flow path 51, through which a heating medium at a higher or lower temperature than the ambient temperature flows, and form an outline longer than the wall thickness t20 in the cross-section. The temperature control panels 20A to B extend along the bed longitudinal direction of the growth beds 10A to C, and the outer surface of at least one of the pair of main walls 31, 32 is positioned close to the culture medium 3 or a plant 2.SELECTED DRAWING: Figure 4

Description

Technical Field

[0006] , , ,

[0001] The present invention relates to a temperature control system and a temperature control panel for plant growth.

Background Art

[0002] Patent Document 1 and Patent Document 2 disclose a growth device that has a water pipe through which a heat medium flows and adjusts the temperature around plants or a medium. For example, the roots of seedlings of plants such as strawberries are allowed to crawl on the outer surface of the water pipe, thereby promoting the growth of the plants.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above device, since the region where the temperature can be adjusted is locally limited, there are limitations in the varieties of plants for which growth can be promoted. In this regard, there is room for improvement in the above device.

[0005] An object of the present invention is to provide a temperature control system and a temperature control panel that contribute to the growth of a wider variety of plants.

Means for Solving the Problems

[0006] One embodiment of the present invention provides a temperature control system for assisting the growth of plants planted in a culture medium, comprising: one or more long cultivation beds that receive the culture medium; and a temperature control panel formed in the shape of a panel having wall thickness, and having a heat medium channel through which a heat medium at a temperature higher or lower than the ambient temperature flows, wherein the temperature control panel has a pair of main walls that face each other in the thickness direction of the temperature control panel, the pair of main walls form a contour that is longer than the wall thickness in cross-section, the temperature control panel extends along the longitudinal direction of the cultivation bed, and at least one outer surface of the pair of main walls is positioned in close proximity to the culture medium or the plants, thereby providing a temperature control system for plant growth.

[0007] According to the above configuration, the temperature control panel has a pair of main walls that define the heat transfer medium flow path. The pair of main walls form a contour that is longer than the wall thickness in cross-section (i.e., a cross-section perpendicular to the longitudinal direction), and therefore has a relatively large outer surface area. The outer surface has a temperature approximately equal to that of the heat transfer medium due to solid heat transfer between it and the heat transfer medium. The outer surface is positioned in close proximity to the growing medium or plant. This makes it possible to control the temperature over a wide area around the growing medium and plant. In contrast to systems in which the temperature is controlled only locally, such as at the base of a seedling, this makes it applicable to the growth of a wider variety of plant species.

[0008] The one or more rows of cultivation beds may include multiple rows of cultivation beds, and the temperature control panel may be positioned between two rows of cultivation beds that are adjacent to each other in the bed width direction, or one row of cultivation beds may be positioned between two temperature control panels in the bed width direction, with the thickness direction of the temperature control panel facing the bed width direction, and the pair of main walls may extend in the bed longitudinal direction and vertical direction.

[0009] This allows for temperature regulation over a wide area surrounding the growing medium within the cultivation bed, which can support the growth of a wide variety of plants.

[0010] At least one of the pair of main walls' outer surfaces may have light-diffusing or light-reflecting properties.

[0011] This allows plants to be illuminated with light diffused or reflected by the temperature control panel, promoting photosynthesis. It also helps to keep light-avoiding pests away from the plants and growing medium.

[0012] The temperature control panel may constitute the bottom of the cultivation bed.

[0013] This makes it easier to adjust the temperature of the growing medium. It can support the growth of a wide variety of plants.

[0014] The temperature control panel may have a receiving portion for receiving the liquid culture medium.

[0015] This allows for adjustment of the temperature of the liquid culture medium.

[0016] The temperature control panel may have a vertical wall portion that extends upward from one end of the receiving portion and is in close proximity to the plant.

[0017] This allows the temperature of the liquid culture medium to be adjusted in the receiving section, and the temperature around the plant extending upward from the culture medium to be adjusted in the vertical wall section.

[0018] The temperature control panel is provided independently of the heat transfer fluid channel and has a gas channel through which a gas containing carbon dioxide flows. An outlet may be provided on the outer surface of at least one of the pair of main walls for ejecting the gas in the gas channel toward the plant.

[0019] This can promote photosynthesis in plants.

[0020] The temperature control panel may have a plurality of heat transfer fluid channels extending parallel to each other.

[0021] This makes it easier to adjust the temperature over a wide area.

[0022] The plurality of heat medium flow paths may be arranged along the contour of the cross-section of the main wall between the pair of main walls.

[0023] Thereby, it is possible to make the wall thickness as thin as possible and widen the area of the outer surfaces of the pair of main walls.

[0024] The plurality of heat medium flow paths may extend in the bed extending direction.

[0025] Thereby, the temperature can be adjusted over a wide range of the culture medium.

[0026] The plurality of heat medium flow paths may include one or more first heat medium flow paths for flowing the heat medium in one direction and one or more second heat medium flow paths for flowing the heat medium in a direction opposite to the one direction.

[0027] Thereby, it becomes easier to adjust the temperature uniformly in the bed longitudinal direction.

[0028] The first heat medium flow path and the second heat medium flow path may be alternately arranged along the cross-section of the pair of main walls.

[0029] Thereby, it becomes easier to adjust the temperature uniformly in the direction in which the heat medium flow paths are arranged.

[0030] The plurality of heat medium flow paths may extend in a direction intersecting the bed extending direction.

[0031] Thereby, it becomes easier to adjust the temperature uniformly in the bed longitudinal direction.

[0032] The temperature adjustment panel may include a main body portion formed of an extruded material and having a hollow portion constituting the heat medium flow path.

[0033] Thereby, the temperature adjustment panel can be provided simply.

[0034] The temperature control panel may further include a pair of headers that close the openings in the hollow portion at each end of the extruded material, and the pair of headers may be provided with an inlet for introducing the heat transfer medium into the heat transfer medium flow path and an outlet for introducing the heat transfer medium out of the heat transfer medium flow path.

[0035] This makes it possible to easily provide a temperature control panel having a sealed heat transfer fluid channel using an extruded material.

[0036] One embodiment of the present invention provides a temperature control panel for assisting the growth of plants planted in a growing medium received in one or more rows of cultivation beds extending in the longitudinal direction of the bed, comprising a main body formed in the shape of a panel having wall thickness and having a heat medium channel formed inside through which a heat medium at a temperature higher or lower than the ambient temperature flows, wherein the main body constitutes the bottom of the cultivation bed, and the outer surface of one of the pair of main walls constitutes the inner bottom surface of the cultivation bed.

[0037] This makes it easier to adjust the temperature of the growing medium and can support the growth of a wide variety of plants. [Effects of the Invention]

[0038] According to the present invention, a temperature control system that contributes to the growth of a wider variety of plants can be provided. [Brief explanation of the drawing]

[0039] [Figure 1] A perspective view of an agricultural greenhouse to which a temperature control system according to the first embodiment of the present invention is applied. [Figure 2] A perspective view of the temperature control panel according to the first embodiment. [Figure 3] An exploded perspective view of the temperature control panel according to the first embodiment. [Figure 4] A cross-sectional view of the temperature control panel and cultivation bed according to the first embodiment. [Figure 5] A longitudinal cross-sectional view of the temperature control panel according to the first embodiment. [Figure 6]A diagram showing the flow of the heat transfer medium in the temperature control system according to the first embodiment. [Figure 7A] An exploded perspective view of a temperature control panel according to a second embodiment of the present invention. [Figure 7B] A longitudinal cross-sectional view of the temperature control panel according to the second embodiment. [Figure 7C] A diagram showing the flow of the heat transfer medium in the temperature control system according to the second embodiment. [Figure 8A] An exploded perspective view of the temperature control panel according to the third embodiment. [Figure 8B] A longitudinal cross-sectional view of the temperature control panel according to the third embodiment. [Figure 8C] A diagram showing the flow of the heat transfer medium in the temperature control system according to the third embodiment. [Figure 9] A diagram showing the flow of the heat transfer medium in the temperature control system according to the fourth embodiment. [Figure 10] A diagram showing the flow of the heat transfer medium in the temperature control system according to the fifth embodiment. [Figure 11A] A cross-sectional view of the temperature control panel and cultivation bed according to the sixth embodiment. [Figure 11B] A cross-sectional view of the temperature control panel and cultivation bed according to the seventh embodiment. [Figure 11C] A cross-sectional view of the temperature control panel and cultivation bed according to the eighth embodiment. [Figure 12A] A cross-sectional view of the temperature control panel and cultivation bed according to the ninth embodiment. [Figure 12B] A cross-sectional view of the temperature control panel and cultivation bed according to the 10th embodiment. [Figure 13A] A cross-sectional view of the temperature control panel and cultivation bed according to the 11th embodiment. [Figure 13B] A cross-sectional view of the temperature control panel and cultivation bed according to the 12th embodiment. [Figure 14A] A cross-sectional view of the temperature control panel and cultivation bed according to the 13th embodiment. [Figure 14B] A cross-sectional view of the temperature control panel and cultivation bed according to the 14th embodiment. [Figure 15A]A cross-sectional view of the temperature control panel and cultivation bed according to the 15th embodiment. [Figure 15B] A cross-sectional view of the temperature control panel and cultivation bed according to the 16th embodiment. [Figure 16A] A cross-sectional view of the temperature control panel and cultivation bed according to the 17th embodiment. [Figure 16B] A cross-sectional view of the temperature control panel and cultivation bed according to the 18th embodiment. [Figure 17A] A cross-sectional view of the temperature control panel and cultivation bed according to the 19th embodiment. [Figure 17B] A cross-sectional view of the temperature control panel and cultivation bed according to the 20th embodiment. [Modes for carrying out the invention]

[0040] Embodiments of the present invention will be described below with reference to the drawings.

[0041] (First Embodiment) Referring to Figure 1, the temperature control system 1 according to the first embodiment is used to assist the growth of plants 2. The plants 2 are preferably crops (agricultural crops such as forage crops, horticultural crops, and industrial crops). The temperature control system 1 adjusts the ambient temperature of the plants 2 and the growing medium 3 in which they are planted. Temperature can be controlled more effectively in a closed environment, and the temperature control system 1 is suitably applied to a closed environment such as an agricultural greenhouse 100. The plants 2 are also suitable if they are suitable for greenhouse cultivation, and in this respect, general crops and horticultural crops are suitable examples among agricultural crops. General crops include wheat, rice, potatoes, and legumes. Horticultural crops include vegetables, fruit trees, and flowers. The growing medium 3 is the growth medium for the plants 2. The growing medium 3 is appropriately selected from soil, rock wool, and nutrient solution, taking into consideration its compatibility with the plants 2 being cultivated.

[0042] The agricultural greenhouse 100 is constructed on a roughly horizontal, rectangular plot of land. The agricultural greenhouse 100 has a frame 101 formed from steel or aluminum extruded material. The entire frame 101 is covered with an outer shell (not shown) formed from a light-transmitting material (e.g., polyvinyl chloride). This protects the interior of the agricultural greenhouse 100 from wind and rain.

[0043] The structural frame 101 includes columns 102 erected at the four corners of the site and in between, a pair of girders 103 horizontally mounted on the upper ends of the columns 102, a plurality of beams 104 horizontally mounted between the girders 102, and a roof structure 105 provided on the girders 103 and beams 104. The shape of the roof is not particularly limited and may be, for example, a gable or an arch. The long sides of the site and the girders 103 are oriented north-south, and the short sides of the site and the beams 104 are oriented east-west. Hereinafter, the direction in which the girders 103 extend will be referred to as the "girder direction," and the direction in which the beams 104 extend will be referred to as the "beam direction."

[0044] The temperature control system 1 comprises multiple rows of cultivation beds 10A, 10B, 10C, and one or more temperature control panels 20A, 20B. The cultivation beds 10A, 10B, 10C and temperature control panels 20A, 20B are installed inside the agricultural greenhouse 100. The number of rows of cultivation beds 10A, 10B, 10C is not limited to three; it may be one row or multiple rows other than three.

[0045] Each cultivation bed 10A, 10B, and 10C is a long, narrow rectangle in plan view. Hereinafter, the longitudinal direction of cultivation beds 10A, 10B, and 10C will be referred to as the "bed longitudinal direction," and the direction perpendicular to the bed longitudinal direction will be referred to as the "bed width direction."

[0046] Each cultivation bed 10A, 10B, and 10C receives the growing medium 3. In this embodiment, the growing medium 3 is soil. In each cultivation bed 10A, 10B, and 10C, multiple plants 2 are planted in the growing medium 3 at intervals along the length of the bed.

[0047] The cultivation bed 10A may have any structure as long as it can accommodate the required culture medium 3. Referring also to Figure 4, as an example, the cultivation bed 10A comprises a container body 11. The container body 11 has a bottom wall 12 and a peripheral wall 13 that rises from the periphery of the bottom wall 12, and the bottom wall 12 and peripheral wall 13 form a receiving section 14 for receiving the culture medium 3. The receiving section 14 is open to the top. The cultivation bed 10A is supported on the grounds of the agricultural greenhouse 100 via legs 19 that extend downward from the bottom wall 12. The culture medium 3 is received into the receiving section 14 from above. The material of the cultivation bed 10A is not particularly limited. The same applies to the other cultivation beds 10B and 10C.

[0048] Each cultivation bed 10A, 10B, and 10C is installed inside the agricultural greenhouse 100 with its longitudinal direction facing the beam direction. Multiple rows of cultivation beds 10A, 10B, and 10C extend parallel to each other and are spaced apart in the beam direction or the bed width direction.

[0049] Referring to Figures 1 and 2, the temperature control panels 20A and 20B are panel-shaped with a wall thickness t20 (see Figure 4). In this embodiment, the temperature control panels 20A and 20B are flat rectangular panels and are independent of the cultivation beds 10A, 10B, and 10C.

[0050] In this case, the temperature control panels 20A and 20B are positioned between two adjacent rows of cultivation beds 10A, 10B, and 10C in the bed width direction. Temperature control panel 20A is positioned between cultivation beds 10A and 10B, and temperature control panel 20B is positioned between cultivation beds 10B and 10C. In other words, the central cultivation bed 10B is positioned between the two temperature control panels 20A and 20B in the bed width direction.

[0051] The thickness direction of temperature control panels 20A and 20B is oriented in the bed width direction (beam direction). The longitudinal direction of temperature control panels 20A and 20B is oriented in the bed longitudinal direction (girder direction). The width direction of temperature control panels 20A and 20B is oriented in the vertical direction.

[0052] The structure of temperature control panel 20A will be explained with reference to Figures 2 to 5. Since temperature control panels 20A and 20B have the same structure, the explanation of temperature control panel 20B will be omitted.

[0053] As shown in Figures 2 and 3, the temperature control panel 20A has a main body 25 and a pair of headers 26, 27 (first header 26 and second header 27).

[0054] The main body 25 is an extruded metal material, with the longitudinal direction of the panel being the extrusion direction. The metal material can be any material that is suitable for extrusion molding, such as aluminum, aluminum alloys, silver, and copper alloys. In this embodiment, the main body 25 is made of aluminum alloy.

[0055] The main body 25 has a pair of main walls 31, 32, a pair of end walls 33, 34, and a plurality of partition walls 35. The main walls 31, 32 face each other in the thickness direction of the temperature control panels 20A, 20B. Each main wall 31, 32 is rectangular in side view and extends in the longitudinal direction of the panel and in the width direction of the panel, which is perpendicular to the longitudinal direction and the thickness direction of the panel. The wall thickness t20 is the distance between the outer surfaces of the pair of main walls 31, 32.

[0056] The end walls 33 and 34 extend in the longitudinal and thickness directions of the panel. The end wall 33 connects one end of a pair of main walls 31 and 32 in the width direction of the panel, and the end wall 34 connects the other ends of a pair of main walls 31 and 32. The main body 25 forms a hollow section 36 surrounded by the main walls 31 and 32 and the end walls 33 and 34. The hollow section 36 opens at both ends of the main body 25 in the longitudinal direction of the panel.

[0057] Multiple partition walls 35 are arranged within the hollow section 36 at intervals from each other in the panel width direction and extend parallel to each other in the panel longitudinal direction. Each partition wall 35 is joined to the inner surface of the main wall 31 at one end in the thickness direction and to the inner surface of the main wall 32 at the other end in the thickness direction. The multiple partition walls 35 divide the hollow section 36 into multiple elongated holes 36a to 36g aligned in the panel width direction. That is, the main body 25 is composed of an extruded material having a multi-chamber structure. Each elongated hole 36a to 36g is defined by the inner surfaces of a pair of main walls 31 and 32, a pair of end walls 33 and 34, and two adjacent inner surfaces of the multiple partition walls 35. The number of elongated holes 36a to 36g is one more than the number of partition walls 35. In this example, the number of elongated holes 36a to 36g is 7, but this can be changed as appropriate.

[0058] As shown in Figure 4, the main walls 31 and 32 form a contour that is longer than the wall thickness t20 in the cross-section (a cross-section perpendicular to the longitudinal direction of the panel). In this embodiment, the main walls 31 and 32 are flat plates, and the main body 25 is a flat rectangular panel. In the cross-section, the contours of the main walls 31 and 32 are straight lines. If we express it more precisely in two dimensions, taking into account the thickness of the main walls 31 and 32, the contour is a long, narrow rectangle. The length of the contour compared to the wall thickness t20 may be defined as the total length of the contour, or as the distance from one end to the other of the contour in the panel width direction. In this embodiment, since the contour is a straight line extending in a direction perpendicular to the thickness direction, both definitions are the same.

[0059] Thus, the contours of the main walls 31 and 32 are longer than the wall thickness t20. In other words, the main walls 31 and 32, and by extension the temperature control panel 20A, are longer in the panel width direction than in the thickness direction, and the temperature control panel 20A is more wall-like or panel-like than cylindrical or rectangular. The aspect ratio of the cross-section of the main body 25 is a value that is significantly different from 1. Furthermore, the length of the main walls 31 and 32 in the panel longitudinal direction is longer than the length of the contour of the main walls 31 and 32 in the cross-section.

[0060] As shown in Figures 3 and 5, the first header 26 is attached to one end of the main body 25 in the longitudinal direction of the panel, closing the opening on one end of the hollow section 36. The second header 27 is attached to the other end of the main body 25 in the longitudinal direction of the panel, closing the opening on the other end of the hollow section 36.

[0061] The first header 26 has a cover plate 41, a peripheral wall 42 erected from the periphery of the cover plate 41, and a recess 43 surrounded by the cover plate 41 and the peripheral wall 42, the recess 43 being open on the side opposite to the cover plate 41. The cross-section of the recess 43 (the cross-section of the inner peripheral surface of the peripheral wall 42) has the same shape as the cross-section of the outer peripheral surface of the main body 25 (rectangular in this embodiment). The first header 26 is fitted onto one end of the main body 25 and is liquid-tightly joined to the main body 25. When mounted on the main body 25, the inner surface of the cover plate 41 is in surface contact with the rectangular window frame-shaped end surface of one end of the main body 25. The second header 27 is configured similarly to the first header 26 and is mounted on the other end of the main body 25 in the longitudinal direction of the panel in the same manner as the first header 26.

[0062] In this embodiment, for all partition walls 35, one end in the longitudinal direction of the panel is offset inward from the end face of the main body 25 that is in surface contact with the cover plate 41. Therefore, all of the elongated holes 36a to 36g open inside the main body 25 at one end. The elongated holes 36a to 36g are in communication with each other via a connecting portion 37 that extends in the panel width direction within the main body 25 between the opening of the main body 25 and the elongated holes 36a to 36g. The same applies to the other end in the longitudinal direction of the panel.

[0063] The temperature control panel 20A has a heat transfer medium channel 51 inside through which a heat transfer medium at a temperature higher or lower than the ambient temperature flows. The ambient temperature is the temperature of the environment in which the plants 2 are placed. In this embodiment, as an example, the ambient temperature is the temperature at a location within the agricultural greenhouse 100 that is a predetermined distance away in the rafter direction from the cultivation beds 10A, 10B, and 10C, that is, a location sufficiently far from the area that can be temperature-controlled by the temperature control panels 20A and 20B. The heat transfer medium can be any substance that enables heat exchange, for example, water or antifreeze mainly composed of ethylene glycol.

[0064] The temperature control panel 20A has an inlet 52 for introducing the heat transfer medium into the heat transfer medium flow path 51 and an outlet 53 for releasing the heat transfer medium from the heat transfer medium flow path. In this embodiment, a single inlet 52 is provided on the cover plate 41 of the first header 26, and a single outlet 53 is provided on the cover plate 41 of the second header 27. The inlet 52 and outlet 53 are located at opposite ends of the panel in the panel width direction. In this embodiment, the panel width direction is oriented vertically within the agricultural greenhouse 100. The temperature control panel 20A is installed in the agricultural greenhouse 100 with the inlet 52 facing downwards and the outlet 53 facing upwards. Nipples for connecting hoses (not shown) through which the heat transfer medium flows are fixed to the inlet 52 and outlet 53.

[0065] The heat transfer fluid flows into the communication section 37 at one end via the inlet 52, and then flows from the communication section 37 into a plurality of elongated holes 36a to 36g. The heat transfer fluid flows from the elongated holes 36a to 36g into the communication section 37 at the other end, and then flows out from the temperature control panel 20A via the outlet 53.

[0066] Thus, the heat transfer fluid channel 51 is composed of a connecting section 37 at one end, a plurality of elongated holes 36a to 36g, and a connecting section 37 at the other end. The plurality of elongated holes 36a to 36g constitute a plurality of individual heat transfer fluid channels 51a that extend in the longitudinal direction of the panel within the temperature control panel 20A. The connecting section 37 at one end functions as a distribution channel 51b that distributes the heat transfer fluid to each of the plurality of individual heat transfer fluid channels 51a. The connecting section 37 at the other end functions as a recovery channel 51c that recovers the heat transfer fluid from each of the plurality of individual heat transfer fluid channels 51a.

[0067] In this embodiment, all of the elongated holes 36a to 36g constitute individual heat transfer fluid channels 51a. Furthermore, in all of the elongated holes 36a to 36g, the heat transfer fluid flows in the same direction from one side to the other in the longitudinal direction of the panel.

[0068] Referring to Figure 6, the temperature control system 100 includes a heat transfer medium temperature control unit 60. The heat transfer medium temperature control unit 60 includes a tank 61, a pump 62, a heater 63, a cooler 64, and a controller 80. The tank 61 stores the heat transfer medium. The outlet of the tank 61 is connected to the suction port of the pump 62. The pump 62 pumps the heat transfer medium from the tank 61 through its discharge port. The tank 61 and the pump 62 may be located inside or outside the agricultural greenhouse 100.

[0069] The discharge port of the pump 62 is connected to the inlet of the tank 61 via the heating line 71. The heater 63 is installed on the heating line 71. The heater 63 is, for example, a solar panel mounted on the beam 104 of the agricultural greenhouse 100, and the heat transfer medium flowing through the heating line 71 is heated by solar heat.

[0070] The discharge port of pump 62 is connected in parallel to the inlet 52 of temperature control panels 20A and 20B via supply line 72. The outlet 53 of temperature control panels 20A and 20B is connected in parallel to the inlet of tank 61 via return line 73.

[0071] A cooling line 74 is provided as a detour for the return line 73. The cooler 64 is installed on the cooling line 74. The cooler 64 is, for example, a heat exchanger embedded underground (for example, to a depth of 20m) on the site of the agricultural greenhouse 100 or an adjacent site.

[0072] In this embodiment, the discharge port of the pump 62 is connected to the inlet of the first three-way valve 65a, and the line from the pump 62 to the first three-way valve 65a serves as both the heating line 71 and the supply line 72. The heating line 71 separates from the supply line 72 at the first three-way valve 65a and extends to the heater 63, while the supply line 72 separates from the supply line 72 at the first three-way valve 65a and extends to the temperature control panels 20A and 20B. The first three-way valve 65a can be switched between a heating state in which the discharge port is connected to the heating line 71 and a supply state in which the discharge port is connected to the supply line 72.

[0073] A second three-way valve 65b is provided in the return line 73. The cooling line 74 extends from the second three-way valve 65b and terminates downstream of the second three-way valve 65b in the return line 73. The second three-way valve 65b can be switched between a direct connection state, where the outlets 53 of the temperature control panels 20A and 20B are connected to the inlet of the tank 61 without going through the cooler 64, and a cooling state, where the outlets 53 are connected to the inlet of the tank 61 via the cooler 64. Check valves 66a and 66b are provided in the cooling line 74 and the return line 73, respectively, before the confluence point, so that the heat transfer medium from the cooling line 74 does not flow back into the return line 73, and vice versa.

[0074] The downstream ends of the heating line 71 and the return line 73 merge to form a single common line 75 connected to the inlet of the tank 61. Check valves 66c and 66d are provided in the heating line 71 and the return line 73, respectively, before the merging point, so that the heat transfer medium does not flow from the heating line 71 to the return line 73 or vice versa.

[0075] The first three-way valve 65a and the second three-way valve 65b are solenoid valves. The controller 80 switches the state of the first three-way valve 65a and the second three-way valve 65b based on control information such as ambient temperature and time. This automates the management of the heat transfer medium flow and temperature. The controller 80 is installed in an operation panel (not shown) located inside the agricultural greenhouse 100.

[0076] As just one example, during the daytime in winter, the controller 80 switches the first three-way valve 65a to the heating state. The state of the second three-way valve 65b is not particularly limited. The heat transfer medium in tank 61 flows through the heating line 71 and returns to tank 61. In the process, the heat transfer medium is heated by solar energy in the heater 63. At night in winter, the heat transfer medium that was heated during the day is stored in tank 61. The controller 80 switches the first three-way valve 65a to the supply state and switches the second three-way valve 65b to the direct connection state. The heat transfer medium in tank 61 is supplied to temperature control panels 20A and 20B via the supply line 72, flows through the heat transfer medium flow path 51 in temperature control panels 20A and 20B, and returns to tank 61 via the return line 73 without passing through the cooler 64.

[0077] During the summer, day and night, the controller 80 switches the first three-way valve 65a to the supply state and the second three-way valve 65b to the cooling state. The heat transfer medium in the tank 61 is supplied to the temperature control panels 20A and 20B via the supply line 72, flows through the heat transfer medium flow path 51 in the temperature control panels 20A and 20B, and then flows through the return line 73. In the process, the heat transfer medium flows through the cooling line 74 and is cooled in the cooler 64, and the cooled heat transfer medium is returned to the tank 61.

[0078] Returning to Figure 4, when a high-temperature heat transfer medium is supplied to the temperature control panels 20A and 20B during winter nights, the heat transfer medium flows into each temperature control panel 20A and 20B from below and flows out from above. With the inlet 52 and outlet 53 arranged in this way, the heat transfer medium is supplied evenly to each of the multiple individual heat transfer medium flow paths 51a. This suppresses the accumulation of air in the heat transfer medium flow path 51, and the temperature can be effectively controlled by the temperature control panels 20A and 20B.

[0079] The heat transfer fluid flows through a heat transfer fluid channel 51 along the longitudinal direction of the panel, i.e., the longitudinal direction of the bed. The outer surfaces of the pair of main walls 31 and 32 of the temperature control panels 20A and 20B are in close proximity to the cultivation bed 3 and the plants 2 extending upward from it, in the panel width direction or the bed width direction. The pair of main walls 31 and 32 are heated by heat conduction from the heat transfer fluid, thereby warming the peripheral region of the outer surface. The culture medium 3 and plants 2 are located in this peripheral region, i.e., within the range that can be temperature controlled by the temperature control panels 20A and 20B. In the cross-section shown in Figure 4, the contour of the outer surface of the pair of main walls 31 and 32 is longer than the wall thickness t20, and this contour extends vertically in the installed state of the temperature control panels 20A and 20B. The temperature control range is expanded vertically compared to the water pipe, and the area around the plants 2 and culture medium 3 is kept at an appropriate temperature over a wider area. The same applies when suppressing excessive temperature increases around plant 2 and growing medium 3 during the summer. This helps to promote the growth of a wider variety of plant 2.

[0080] The outer surfaces of the temperature control panels 20A and 20B have light-diffusing or light-reflecting properties. To obtain light-diffusing or light-reflecting properties, for example, the outer surfaces may be painted white, or they may be left unpainted and in their natural state. The outer surfaces diffuse or reflect sunlight that has passed through the outer shell of the agricultural greenhouse 100, and the diffused or reflected light irradiates the plants 2 or the growing medium 3. This keeps light-avoiding pests away from the plants 2 and the growing medium 3, and promotes the growth of the plants 2. In addition, directing the light towards the plants 2 promotes photosynthesis in the plants 2.

[0081] (Second Embodiment) Next, with reference to Figures 7A to 7C, a second embodiment of the present invention will be described, focusing on the differences from the above embodiment. In this embodiment as well, the temperature control panels 20A and 20B have the same structure, so the description of the temperature control panel 20B will be omitted.

[0082] One of the seven elongated holes 36a to 36g, elongated hole 36d, constitutes a gas channel 56 through which a gas containing carbon dioxide flows. The remaining elongated holes 36a to 36c and 36e to 36g constitute individual heat transfer fluid channels 51a. Elongated hole 36d is located in the center of the seven elongated holes 36a to 36g.

[0083] With respect to the two partition walls 35C and 35D that define the elongated hole 36d, one end in the longitudinal direction of the panel is flush with the end face of one end of the main body portion 25 that is in surface contact with the cover plate 41. The other partition walls 35 are the same as in the first embodiment. The elongated holes 36a to 36c are connected to each other via a one-sided connecting portion 37a that extends in the panel width direction within the main body portion 25 between the opening of the main body portion 25 and the elongated holes 36a to 36c. The elongated holes 36e to 36g are connected to each other via a other-sided connecting portion 37b that extends in the panel width direction within the main body portion 25 between the opening of the main body portion 25 and the elongated holes 36e to 36g. The same applies to the other end in the longitudinal direction of the panel.

[0084] With respect to the two partition walls 35C and 35D that define the elongated hole 36d, one end in the longitudinal direction of the panel is flush with the end face of one end of the main body portion 25 that is in surface contact with the cover plate 41. The other partition walls 35 are the same as in the first embodiment. The elongated holes 36a to 36c are connected to each other via a one-sided connecting portion 37a that extends in the panel width direction within the main body portion 25 between the opening of the main body portion 25 and the elongated holes 36a to 36c. The elongated holes 36e to 36g are connected to each other via a other-sided connecting portion 37b that extends in the panel width direction within the main body portion 25 between the opening of the main body portion 25 and the elongated holes 36e to 36g. The same applies to the other end in the longitudinal direction of the panel.

[0085] The pair of main walls 31 and 32 are provided with multiple outlets 38 that connect the gas passage 56 to the outside, i.e., the elongated holes 36d (see Figure 7A for the outlets 38 of main wall 31, and Figure 7B for the outlets 38 of main wall 32). The multiple outlets 38 are spaced apart from each other and arranged in the direction of extension of the gas passage 56, i.e., in the longitudinal direction of the panel.

[0086] The first header 26 is provided with two inlets 52a, 52b and one gas inlet 56. The second header 27 is provided with two outlets 53a, 53b. When the pair of headers 26, 27 are attached to the main body 25, the partitions 35C, 35D abut against the inner surface of the cover plate 41. As a result, the central elongated hole 36d communicates with the gas inlet 57 and the outlet 38, while being isolated from the other elongated holes 36a-36c, 36e-36g, and the inlets 52a, 52b and outlets 53a, 53b.

[0087] The first inlet 52a is connected to the first outlet 53a via the one-sided communication section 37a of the first header 26, three elongated holes 36a to 36c, and the one-sided communication section 37a of the second header 27. The second inlet 52b is connected to the second outlet 53b via the one-sided communication section 37b of the first header 26, three elongated holes 36e to 36g, and the one-sided communication section 37b of the second header 27. The communication sections 37a and 37b of the first header 26 constitute a distribution channel 51b, the elongated holes 36a to 36c and 36d to 36e constitute individual heat transfer fluid channels 51a, and the communication sections 37a and 37b of the second header 27 constitute a recovery channel 51c. The first inlet 51a is positioned below the first outlet 51b, and the second inlet 51b is positioned below the second outlet 52b. In the individual heat transfer fluid channels 51a, the heat transfer fluid flows in the same direction. This makes it possible to maintain an appropriate temperature over a wide area around the plant 2 and the culture medium 3, similar to the first embodiment.

[0088] The gas inlet 56 is connected to the gas supply source 81 via the gas supply line 82. The gas supply source 82 may be a tank storing high-pressure gas containing carbon dioxide, or it may be a pump or compressor that pumps air. The gas containing carbon dioxide is introduced into the gas flow path 56 of the temperature control panels 20A and 20B via the gas supply line 82 and the gas inlet 56. The introduced gas is ejected from multiple outlets 38 toward the plants 2. This promotes photosynthesis in the plants 2.

[0089] (Third embodiment) Next, with reference to Figures 8A to 8C, a third embodiment of the present invention will be described, focusing on the differences from the above embodiment. In this embodiment as well, the temperature control panels 20A and 20B have the same structure, so the description of the temperature control panel 20B will be omitted.

[0090] In this embodiment, for all partition walls 35, one end in the longitudinal direction of the panel is flush with the end face of one end of the main body portion 25 that is in surface contact with the cover plate 41. Therefore, the main body portion 25 does not have a portion corresponding to the communication portion 37 in the first embodiment (see Figures 3 and 5) or the one-sided communication portion 37a and the other-sided communication portion 37b in the second embodiment (see Figures 7A and 7B). The same applies to the other end in the longitudinal direction of the panel.

[0091] When the pair of headers 26 and 27 are attached to the main body 25, all the partitions 35 abut against the inner surface of the cover plate 41. As a result, the seven elongated holes 36a to 36g are isolated from each other, forming independent flow paths.

[0092] The first header 26 is provided with three inlets 52a, 52c, and 52f, three outlets 52b, 52e, and 52g, and one gas inlet 56. The second header 27 is provided with three inlets 52b, 52e, and 52g, and three outlets 53a, 53c, and 53f. The gas inlet 56 communicates with the elongated hole 36d, as in the second embodiment, and the elongated hole 36d constitutes the gas flow path 56.

[0093] The elongated hole 36a communicates with the inlet 52a and the outlet 52a. The elongated hole 36a constitutes a first individual heat medium flow channel 51a1 that allows the heat medium to flow from one side to the other in the longitudinal direction of the panel. The elongated hole 36b communicates with the inlet 52b and the outlet 52b. The elongated hole 36b constitutes a second individual heat medium flow channel 51a2 that allows the heat medium to flow from the other side to the one side in the longitudinal direction of the panel. The elongated holes 36c and 36f constitute the first individual heat medium flow channel 51a1. The elongated holes 36d and 36g constitute the second individual heat medium flow channel 51a2. The first individual heat medium flow channel 51a1 and the second individual heat medium flow channel 51a2 are arranged alternately in the width direction of the panel.

[0094] As the heat transfer medium flows through the individual heat transfer medium channels, its temperature may change due to heat exchange with the internal air of the agricultural greenhouse 100. In this embodiment, the first individual heat transfer medium channel 51a1, which allows the heat transfer medium to flow from one side to the other, and the second individual heat transfer medium channel 51a2, which allows the heat transfer medium to flow from the other side to the one side, are mixed within the temperature control panels 20A and 20B. This makes it possible to homogenize the ambient temperature on one side of the temperature control panel 20A with the ambient temperature on the other side. Since the first individual heat transfer medium channel 51a1 and the second individual heat transfer medium channel 51a2 are arranged alternately, the temperature can also be homogenized in the vertical direction.

[0095] (Fourth Embodiment) Next, with reference to Figure 9, a fourth embodiment of the present invention will be described, focusing on the differences from the above embodiment. In this embodiment as well, the temperature control panels 20A and 20B have the same structure, so the description of the temperature control panel 20B will be omitted.

[0096] The temperature control panel 20A may have multiple main body sections 25 arranged in the longitudinal direction of the panel. In this case, the temperature control panel 20A has one or more intermediate heads 28 connecting the main body sections 25. In the illustrated example, there are two main body sections 25, so there is one intermediate head 28, but if there are three or more main body sections 25, multiple intermediate heads 28 can be provided on the temperature control panel 20A. The intermediate head 28 has a shape such that the cover plate 41 of the second head 27 and the cover plate 41 of the first head 26 are glued back to back. One side in the longitudinal direction of the panel has a structure equivalent to that of the second head 27, and the other side in the longitudinal direction of the panel has a structure equivalent to that of the first head 26. The inlet 52 and outlet 53 are provided on the peripheral wall 42 instead of the cover plate 41.

[0097] This makes it possible to provide elongated temperature control panels 20A and 20B even when the cultivation beds 10A, 10B, and 10C are elongated in the longitudinal direction of the bed.

[0098] In the illustrated example, the gas flow paths 56 according to the second and third embodiments (see Figures 7A and 8A) are not provided, but the gas flow paths 56 can also be applied in this embodiment. In the illustrated example, all individual heat medium flow paths 51a allow the heat medium to flow from one side to the other, but in this embodiment, a first individual heat medium flow path 51a1 and a second individual heat medium flow path 51a2 (see Figure 8B) may also be provided.

[0099] (Fifth embodiment) Next, with reference to Figure 10, a fifth embodiment of the present invention will be described, focusing on the differences from the above embodiment. In this embodiment as well, the temperature control panels 20A and 20B have the same structure, so the description of the temperature control panel 20B will be omitted.

[0100] In this embodiment, a row of temperature control panels 20A adjacent to the cultivation bed 10A is constructed by arranging multiple temperature control panels 20A1, 20A2 in the longitudinal direction of the bed. This makes it possible to provide long temperature control panels 20A according to the length of the cultivation beds 10A, 10B, 10C, as in the fourth embodiment.

[0101] In this embodiment, the individual heat transfer fluid channels 51a within each temperature control panel 20A1, 20A2 are oriented vertically. This allows the ambient temperature on one side of the temperature control panel 20A to be made uniform with the ambient temperature on the other side. All individual heat transfer fluid channels 51a circulate the heat transfer fluid from bottom to top. This prevents air from accumulating in the heat transfer fluid channels 51.

[0102] In the illustrated example, when dividing a single row of temperature control panels 20A into multiple panels 20A1, 20A2, the individual heat transfer fluid channels 51a are oriented vertically. However, the individual heat transfer fluid channels 51a may be oriented along the longitudinal direction of the bed, as in the first to fourth embodiments.

[0103] In the illustrated example, when dividing a single row of temperature control panels 20A into multiple panels, the individual heat transfer fluid channels 51a are oriented vertically. However, the individual heat transfer fluid channels 51a may be oriented along the longitudinal direction of the bed, as in the first to fourth embodiments. In this embodiment as well, the gas channel 56 (see Figures 7A and 8A) can be applied, and the first individual heat transfer fluid channel 51a1 and the second individual heat transfer fluid channel 51a2 (see Figure 8B) can be configured.

[0104] (Sixth Embodiment) Next, with reference to Figure 11A, a sixth embodiment of the present invention will be described, focusing on the differences from the above embodiment.

[0105] In the above embodiment, the temperature control panel 20A was installed adjacent to the cultivation bed 10A, but in this embodiment to the 20th embodiment, the temperature control panel 120A constitutes part of the cultivation bed 3.

[0106] In this embodiment, the temperature control panel 20A constitutes the bottom of the cultivation bed 10A. The temperature control panel 20A is supported on the ground of the agricultural greenhouse 100 via legs 19, with a pair of main walls 31, 32 facing upward or downward. The container body 11 of the cultivation bed 10A is placed on the upper surface of the main wall 31. In this way, the temperature control panel 20A functions as a base on which the container body 11 is placed.

[0107] As a result, the temperature of the bottom wall 12 of the container 11 is adjusted by solid heat transfer. In addition, the temperature of the peripheral wall 13 of the container 11 is also adjusted by the temperature control panel 20A. This makes it possible to adjust the temperature of the culture medium 3 contained in the container 11 over a wide range.

[0108] (Seventh Embodiment) Next, with reference to Figure 11B, a seventh embodiment of the present invention will be described, focusing on the differences from the above-described embodiment.

[0109] In this embodiment, the container body 11 has a W-shaped cross-section overall and an inverted V-shaped partition wall portion 15 in the center in the width direction. Two receiving portions 14 are arranged in the width direction via the partition wall portion 15. The culture medium 3 is received in each of the two receiving portions 14. The temperature control panel 20A functions as a base on which the container body 11 is placed, similar to the sixth embodiment.

[0110] The partition wall 15 has an upward-facing recess 15a on its lower surface. The temperature control panel 20A has fins 39 protruding from the main wall 31, and the fins 39 are inserted into the recess 15a. This allows the temperature of the partition wall 15 to be adjusted by the fins 39, even though the container body 11 has a partition wall 15.

[0111] (Eighth embodiment) Next, with reference to Figure 11C, an eighth embodiment of the present invention will be described, focusing on the differences from the above embodiment.

[0112] In the above embodiment, the elongated holes 36a to 36g are arranged linearly in the panel width direction. However, in this embodiment, the central elongated hole 36d is offset in the thickness direction relative to the other elongated holes 36a to 36c and 36e to 36g. As a result, the main walls 31 and 32 are not flat, and there is a step in the thickness direction at the portion defining the elongated hole 36d. This allows the stepped portion to fit into the recess 15a. Therefore, the temperature of the partition wall 15 can be adjusted in the same manner as in the sixth embodiment.

[0113] (Ninth Embodiment) Next, with reference to Figure 12A, a ninth embodiment of the present invention will be described, focusing on the differences from the above-described embodiment.

[0114] The temperature control panel 20A is formed in a U-shape in cross-section and is supported on the ground of the agricultural greenhouse 100 via legs 19. In cross-section, the contours of the outer surfaces of the pair of main walls 31, 32 are not straight or elongated rectangular as in the first to seventh embodiments. The contours may be convex downwards, curved, or composed of multiple steps as shown in the illustrated example. In this embodiment as well, the contours are elongated relative to the wall thickness t20. The cultivation bed 10A is housed within the temperature control panel 20A. As a result, not only the bottom wall 12 of the container body 11 but also the peripheral wall 13 faces the outer surface of the main wall 31 in the bed width direction. Therefore, compared to the sixth embodiment, it becomes easier to adjust the temperature of the growing medium 3.

[0115] (Tenth embodiment) Next, with reference to Figure 12B, a tenth embodiment of the present invention will be described, focusing on the differences from the above embodiment.

[0116] The temperature control panel 20A is formed in a U-shape in cross-section and has a bottom wall portion 20a and a pair of side wall portions 20b that protrude upward from both ends of the bottom wall portion 20a. The temperature control panel 20A has a plurality of fins 39 that protrude from the inner circumferential surfaces of the bottom wall portion 20a and the side wall portions 20b.

[0117] The culture medium 3 is, for example, rock wool. Unlike soil or culture medium, rock wool has a high ability to maintain its shape without losing its form, and as in the above embodiment, the cultivation bed 10A does not necessarily have to be equipped with a container body 11. The fins 39 contribute to stabilizing the position of such exposed rock wool relative to the temperature control panel 20A. That is, the fins 39 protruding from the inner surface of the side wall portion 20b stabilize the position of the rock wool relative to the panel width direction, and a part of the fins 39 protruding from the inner surface of the bottom wall portion 20a can also stabilize the position of the rock wool relative to the panel width direction. A part of the fins 39 protruding from the inner surface of the bottom wall portion 20a may be pierced into the rock wool from below, which can further stabilize the position of the rock wool relative to the temperature control panel 20A.

[0118] Because the culture medium 3 is surrounded by the side walls, it is easy to adjust the temperature of the culture medium 3. In addition, because the fins 39 are close to, in contact with, or immersed in the rock wool, it is even easier to adjust the temperature of the culture medium 3.

[0119] (11th embodiment) Next, with reference to Figure 13A, an eleventh embodiment of the present invention will be described, focusing on the differences from the above embodiment.

[0120] In this embodiment, the cross-sectional structure of the temperature control panel 20A is the same as in the ninth embodiment (see Figure 12A). A culture medium is used in the culture medium 3, and the temperature control panel 20A functions not so much as a base for supporting the container body 11, but rather as a receiving section 14 for receiving the liquid culture medium 3.

[0121] In this case, detailed illustrations are omitted, but the headers 26 and 27 of the temperature control panel 20A also have closing plates that close the longitudinal ends of the receiving section 14 to prevent the culture medium from leaking out. In addition, a system for circulating the culture medium is added to the temperature control system 100 to manage the water quality and temperature of the culture medium.

[0122] In this embodiment as well, the temperature of the culture medium 3 is adjustable. The outer surface of the main wall 31 facing the culture medium 3 may be treated with a corrosion-preventive surface treatment. This prevents the temperature control panel 20A from corroding in the culture medium 3 and also prevents the material of the temperature control panel 20A from leaching into the culture medium 3.

[0123] The main body 25 of the temperature control panel 20A is made of an extruded material having numerous elongated holes. The liquid level of the culture medium 3 is at approximately the same height as the partition wall that separates a pair of elongated holes located at the upper end. Thus, these upper elongated holes constitute a gas flow path 56, and the remaining elongated holes located below them constitute individual heat transfer fluid flow paths 51a. This makes it possible to simultaneously promote photosynthesis with gas sprayed onto the plants 2 and regulate the temperature of the liquid culture medium 3.

[0124] (12th embodiment) Next, with reference to Figure 13B, a twelfth embodiment of the present invention will be described, focusing on the differences from the above embodiment.

[0125] In this embodiment, the cross-sectional structure of the temperature control panel 20A is the same as in the tenth embodiment (see Figure 12B). As in the eleventh embodiment, a culture medium is used for the culture medium 3. The bottom wall portion 20a and the pair of side wall portions 20b function as receiving portions 14 for receiving the culture medium 3. This allows the temperature of the liquid culture medium 3 to be adjusted, similar to the tenth and eleventh embodiments.

[0126] (13th Embodiment) Next, with reference to Figure 14A, a thirteenth embodiment of the present invention will be described, focusing on the differences from the above embodiment.

[0127] In this embodiment, as in the tenth embodiment, the culture medium 3 is received by the temperature control panel 20A. The temperature control panel 20A has a U-shaped receiving portion 14 for receiving the culture medium 3, as well as a vertical wall portion 16 extending upward from one upper end of the receiving portion 14, and is formed in a J-shape overall. The vertical wall portion 16 is in close proximity to and opposite the plant 2 that extends upward from the culture medium 3. This allows the temperature of the liquid culture medium 3 to be adjusted by the receiving portion 14, and the temperature around the plant 2 that extends upward from the culture medium 3 to be adjusted by the vertical wall portion 16. This can further promote the growth of the plant 2 cultivated in the culture solution.

[0128] (14th Embodiment) Next, with reference to Figure 14B, a 14th embodiment of the present invention will be described, focusing on the differences from the above embodiment.

[0129] In this embodiment, similar to the thirteenth embodiment, the temperature control panel 20A has a receiving portion 14 and a vertical wall portion 16. The temperature control panel 20A has fins 39 protruding from the inner surface of the vertical wall portion 16 (the surface facing the plant 2). This makes it easier to further adjust the temperature around the plant 2.

[0130] (15th Embodiment) Next, with reference to Figure 15A, a 15th embodiment of the present invention will be described, focusing on the differences from the above embodiment.

[0131] In this embodiment, similar to the 14th embodiment, the temperature control panel 20A has a receiving portion 14, a vertical wall portion 16, and fins 39. The receiving portion 14 forms individual heat transfer fluid channels 51a, while the vertical wall portion 16 does not have a hollow structure and is plate-shaped. The fins 39 protrude from such vertical wall portion 16. In this embodiment as well, it is easy to adjust the temperature around the culture medium 3 and the plant 2. The culture medium 3 may be soil or a culture solution.

[0132] (16th Embodiment) Next, with reference to Figure 15B, a 16th embodiment of the present invention will be described, focusing on the differences from the above-described embodiment.

[0133] In this embodiment, similar to the 15th embodiment, the temperature control panel 20A has a receiving portion 14, a vertical wall portion 16, and fins 39. The receiving portion 14 forms individual heat transfer fluid channels 51a in its central portion and is plate-shaped at both ends in the width direction. In this embodiment as well, it is easy to adjust the temperature around the culture medium 3 and the plants 2. The culture medium 3 may be soil or a culture solution.

[0134] (17th Embodiment) Next, with reference to Figure 16A, a 17th embodiment of the present invention will be described, focusing on the differences from the above embodiment.

[0135] The temperature control panel 20A has a receiving portion 14 for receiving the culture medium 3, similar to the 11th or 12th embodiment. In this embodiment, the receiving portions 14 are paired in the width direction. The pair of receiving portions 14 are connected and integrated in the width direction. This makes it easier to increase the planting area in the agricultural greenhouse 100 while adopting a configuration that allows for temperature adjustment of the culture medium 3.

[0136] (18th embodiment) Next, with reference to Figure 16B, an 18th embodiment of the present invention will be described, focusing on the differences from the above embodiment.

[0137] The temperature control panel 20A has a pair of receiving portions 14, similar to the 17th embodiment. Both ends of the receiving portions 14 in the width direction are plate-shaped, similar to the 16th embodiment. In this embodiment, there is a connecting wall 17 that connects the vertically central portions of the receiving portions 14. This increases the section modulus in the region between the pair of receiving portions 14, thereby ensuring strength.

[0138] (19th embodiment) Next, with reference to Figure 17A, a 19th embodiment of the present invention will be described, focusing on the differences from the above embodiment.

[0139] The temperature control panel 20A has a pair of receiving portions 14, similar to the 17th embodiment. The temperature control panel 20A further has vertical wall portions 16 that protrude upward from the connection portion of the pair of receiving portions 14. This allows for the adjustment of the temperature around the plants 2 planted in the culture medium 3 within the pair of receiving portions 14.

[0140] (20th embodiment) Next, with reference to Figure 17B, an eighth embodiment of the present invention will be described, focusing on the differences from the above embodiment.

[0141] The temperature control panel 20A has a pair of receiving portions 14, similar to the 18th embodiment, and a vertical wall portion 16, similar to the 19th embodiment. In this embodiment as well, the temperature around the plant 2 can be adjusted in the same manner as in the 19th embodiment.

[0142] Embodiments of the present invention have been described so far, but the above configurations can be added, modified, or deleted as appropriate within the scope of the spirit of the present invention.

[0143] For example, the molding method for the main body 25 is not particularly limited. In this embodiment, the main body 25 is made of an extruded material, for example, but it may also be made of a single sheet by roll molding. Using extrusion molding, the main body 25 having the above structure can be easily manufactured.

[0144] Furthermore, the tanks may be separated into one for heated high-temperature heat transfer fluid and another for cooled low-temperature heat transfer fluid. Pumps can be added as needed to ensure the required pressure. Cooling can be carried out using the ground, and groundwater (well water) may be used as the heat transfer fluid. If a flow path for the heat transfer fluid is formed inside the pillars of the agricultural greenhouse 100, the portion of the pillar embedded in the ground may constitute the cooling line. [Explanation of Symbols]

[0145] 1. Temperature control system 2 plants 3. Culture medium 10A, 10B, 10C cultivation beds 20A, 20B Temperature Control Panel 14 Receptor part 16 Vertical wall section 21 Heat transfer fluid channel 25 Main body 26,27 Header 31,32 Main wall 33,34 End wall 35 Partition wall 38 spout 51 Heat transfer fluid channel 51a Individual heat transfer fluid channels 51a1 First individual heat transfer fluid channel 51a2 Second individual heat transfer fluid channel 52 Inlet 53 Outlet 56 Gas flow path

Claims

1. A temperature control system for assisting the growth of plants planted in a growing medium, A long cultivation bed comprising one or more rows for receiving the culture medium, A temperature control panel is formed in the shape of a panel with wall thickness, and has a heat transfer medium channel formed inside through which a heat transfer medium at a temperature higher or lower than the ambient temperature flows, The temperature control panel has a pair of main walls facing each other in the thickness direction of the temperature control panel, and in a cross-section perpendicular to the longitudinal direction of the temperature control panel, the distance from one end to the other of the pair of main walls in the panel width direction is longer than the wall thickness, and the heat transfer fluid flow path is defined by the pair of main walls. The temperature control panel extends along the longitudinal direction of the cultivation bed, and the outer surface of at least one of the pair of main walls is positioned in close proximity to the growing medium or the plants. A temperature control system for plant growth.

2. The aforementioned one or more rows of cultivation beds includes multiple rows of the aforementioned cultivation beds, The temperature control panel is positioned between two adjacent rows of cultivation beds in the bed width direction, or one row of cultivation beds is positioned between two temperature control panels in the bed width direction. The thickness direction of the temperature control panel is oriented in the direction of the bed width, and the pair of main walls extend in the longitudinal direction and vertical direction of the bed. A temperature control system for plant growth according to claim 1.

3. At least one of the pair of main walls has an outer surface that is light-diffusing or light-reflecting. The temperature control system for plant growth according to claim 2.

4. The temperature control panel constitutes the bottom of the cultivation bed. A temperature control system for plant growth according to claim 1.

5. The temperature control panel has a receiving portion for receiving the liquid culture medium. The temperature control system for plant growth according to claim 4.

6. The temperature control panel has a vertical wall portion that extends upward from one end of the receiving portion and is in close proximity to the plant. The temperature control system for plant growth according to claim 5.

7. The temperature control panel is provided independently of the heat transfer fluid channel and has a gas channel through which a gas containing carbon dioxide is passed. An outlet is provided on the outer surface of at least one of the pair of main walls for ejecting the gas in the gas channel toward the plant. A temperature control system for plant growth according to claim 1.

8. The temperature control panel forms a plurality of heat transfer fluid channels that extend parallel to each other. A temperature control system for plant growth according to any one of claims 1 to 7.

9. The plurality of heat transfer fluid channels are arranged between the pair of main walls along the width direction of the panel. A temperature control system for plant growth according to claim 8.

10. The plurality of heat transfer fluid channels extend in the direction of the bed extension, A temperature control system for plant growth according to claim 8.

11. The plurality of heat transfer fluid passages include one or more first heat transfer fluid passages that allow the heat transfer fluid to flow in one direction, and one or more second heat transfer fluid passages that allow the heat transfer fluid to flow in the opposite direction to the aforementioned one direction. A temperature control system for plant growth according to claim 10.

12. The first heat transfer fluid channel and the second heat transfer fluid channel are arranged alternately along the cross-sections of the pair of main walls. The temperature control system for plant growth according to claim 11.

13. The plurality of heat transfer fluid channels extend in a direction intersecting the bed extension direction, A temperature control system for plant growth according to claim 8.

14. The temperature control panel has a hollow portion that constitutes the heat transfer fluid channel and includes a main body made of extruded material. A temperature control system for plant growth according to any one of claims 1 to 7.

15. The temperature control panel further includes a pair of headers that close the openings in the hollow portion at each end of the extruded material, The pair of headers are provided with an inlet for introducing the heat transfer medium into the heat transfer medium channel and an outlet for introducing the heat transfer medium out of the heat transfer medium channel. A temperature control system for plant growth according to claim 14.

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