JP5830211B2 - Greenhouse cultivation system - Google Patents

Description

  The present invention relates to a greenhouse cultivation system.

  The greenhouse is originally installed for the purpose of promoting the growth of plants in the low temperature period, and has a very high function of converting solar energy into heat. For this reason, even in winter, there is no need for heating during the day when solar radiation is strong, rather, the skylight is opened and exhausted, and the temperature in the greenhouse is lowered by ventilation. And at night when the temperature drops, the heating equipment is operated to heat the inside of the greenhouse and adjust the temperature. However, with regard to such heating control, it is required to reduce fuel costs and electricity costs because of cost savings and environmental protection requirements. On the other hand, in the cultivation of crops, it is always required to increase the yield of crops per unit area and improve profits.

  In view of the above, for example, as described in Non-Patent Document 1, in the Netherlands, aquifers, which are almost non-moving waters located about 100 m underground, are used to store cold water and hot water storage masses. It has been used as. Heat in the greenhouse heated by solar energy in summer is stored in the aquifer with a heat pump to cool the greenhouse, and in winter, the heat in the aquifer is used to heat the greenhouse with a heat pump. By adopting such a configuration, when considered throughout the year, the operation time of the heating facility can be shortened, and the heating cost can be reduced. In addition, since the temperature can be controlled at low cost by using the heat of the aquifer with a heat pump, the ventilation time is short throughout the year, and it is a closed type that does not ventilate with ventilation equipment such as skylights and side windows, Or it can be set as the semi-closed type greenhouse which suppressed the ventilation by ventilation equipment to the minimum necessary. By using closed and semi-closed greenhouses and actively applying carbon dioxide, the carbon dioxide concentration in the greenhouse can be maintained at 2-4 times the atmospheric concentration, increasing the photosynthetic rate of crops, The yield can be improved. Non-patent document 2, for example, describes that the photosynthetic rate is increased by increasing the carbon dioxide concentration above the atmospheric concentration.

"Netherlands semi-closed house aiming at environmental conservation and high yield" (Akira Saito), Facility and Horticulture No. 144, p25-31, published on January 30, 2009 “Theory of CO2 Application to Strawberry” (Yasaburo Oda), Bulletin of the 1997 Strawberry Seminar and others, p6-10

  However, the technique of Non-Patent Document 1 can be implemented only in a place where the aquifer as described above exists nearby, and is not practical in Japan where there is almost no such aquifer. In Non-Patent Document 2, carbon dioxide can be applied to increase the carbon dioxide concentration and promote photosynthesis in the time period from sunrise to the start of heat dissipation ventilation. There is no mention of keeping it high.

  This invention is made | formed in view of the above, and makes it a subject to provide the cultivation system for greenhouses which can aim at the reduction of air-conditioning cost and the improvement of an energy-saving effect, without utilizing an aquifer. In addition to improving the energy saving effect, it is an object to provide a greenhouse cultivation system that can improve the quality and yield of crops by keeping carbon dioxide concentration and humidity appropriately during the daytime. To do.

  In order to solve the above problems, the greenhouse cultivation system of the present invention is arranged in a greenhouse, and a heat transfer section that promotes heat exchange between the air in the greenhouse and the heat storage body filled therein is provided on the side surface. And a heat pump for transferring heat to a heat storage body in the heat exchanger / heat accumulator.

  The heat pump is preferably installed in a greenhouse. The heat transfer part is made of a plate-like member having a corrugated cross section, and is preferably arranged in a direction in which each valley portion is substantially horizontal to the floor surface, and the heat transfer part has a thermal conductivity of 50 W / ( mk) to 300 W / (mk).

  It is preferable that the ratio of the height to the cross-sectional width of the heat exchanger / heat accumulator is larger than 1. It is preferable that the heat exchanger / heat accumulator is provided in the greenhouse under a cultivation bed located at a predetermined height from the ground surface. The heat exchanger / heat accumulator is disposed inside the pair of leg members disposed at a predetermined interval in the cross-sectional width direction, and is between the pair of leg members, the heat exchanger / heat accumulator. It is preferable that the beam member is horizontally stretched above and the cultivation bed is supported on the horizontally stretched beam member.

  It is preferable that a reflection sheet capable of covering the heat transfer portion located on the side surface of the heat exchange / heat accumulator is provided. The reflection sheet is preferably provided so as to be openable and closable at a position spaced apart from the heat transfer section by a predetermined distance so as to cover the heat transfer section and not cover the heat transfer section. It is preferable that a blower conduit capable of supplying carbon dioxide is provided between the heat exchanger / heat accumulator and the reflection sheet.

  It is preferable that an underground heat storage unit is provided in the ground in the greenhouse, and the heat exchanger / heat storage unit is provided with a bottom surface in contact with the ground, and the bottom surface is between the underground heat storage unit. It is preferable to constitute a heat transfer section capable of heat exchange.

  This invention is the structure which has arrange | positioned the heat exchange and the thermal storage device by which the heat-transfer part which encourages heat exchange between the air in a greenhouse and the thermal storage body with which it was filled in the side surface was provided in the greenhouse. Since the heat transfer part is provided on the side surface of the heat exchanger / heat accumulator, for example, compared with the case where the heat transfer part is provided on the upper surface where the cultivation bed is arranged, a wide contact area with the air in the greenhouse can be secured, Excess heat in the greenhouse in the daytime can be efficiently exchanged through this heat transfer section due to the temperature difference between the heat storage body filled in the heat exchanger / heat accumulator and the air in the greenhouse. As a result, the operating rate of the heat pump can be reduced, contributing to cooling during the daytime, contributing to shortening the ventilation time, and the stored heat can be used for heating at night, and the cooling / heating costs can be greatly reduced.

  Moreover, this invention also has the heat pump which transfers heat | fever to the heat storage body in the said heat exchange and heat storage device. Therefore, by operating the heat pump according to the room temperature during the day, solar heat can be collected and held in the heat storage body, and the heat stored in the heat storage body can be used for nighttime heating. . Since this invention has not only a heat pump but the above-mentioned heat exchanger / heat accumulator, it collects heat naturally when the temperature of the heat accumulator is lower than room temperature. It is only necessary to operate the heat pump only when natural heat collection alone cannot maintain the predetermined room temperature, and even if the heat storage body becomes low temperature due to heating, the heat drop between the temperature of the heat transfer section and the temperature of the surrounding air Since the natural heat collection efficiency of the next day becomes high, the heat collection (cooling) time by the heat pump can be shortened, and the heating and cooling costs can be greatly reduced. In addition, the combination of the heat exchanger / heat accumulator and the heat pump can maintain the room temperature during the day at a predetermined temperature while suppressing the cooling cost, so that ventilation for cooling can be eliminated. As a result, not only in the morning but also in the daytime, it is possible to appropriately maintain the carbon dioxide concentration and humidity in the room and increase the photosynthetic rate. Furthermore, since ventilation becomes unnecessary, the effect of preventing the invasion of pests and insecticides is enhanced, and the amount of agricultural chemicals used and the spraying time can be reduced.

  In addition, by adopting a configuration in which a heat exchanger / heat accumulator is provided below the cultivation bed, a special space for arranging the heat exchange / heat accumulator is not required, and the effective cultivation area in the greenhouse can be reduced. Absent. In addition, if the room temperature falls below the heat storage temperature at night, the plant is warmed by convection and radiation from the heat transfer section located on the side of the heat exchanger / heat storage. By placing the plant under the cultivation bed, the heat storage / heat accumulator position overlaps with the crop planting position in a plane, thus mitigating the impact on the crops caused by sudden changes in room temperature. can do.

  Moreover, since the heat exchanger / regenerator is located below the cultivation bed, the weight of the heat exchanger / regenerator can be transmitted directly to the ground, and no special support structure is required. Since it is installed directly on the ground, heat exchange is performed with the ground via the bottom of the heat exchanger / heat accumulator. Thereby, since the underground temperature is stabilized, when the underground heat storage portion is provided, it is not necessary to provide a heat insulating structure that covers the underground heat storage portion, which contributes to a reduction in construction cost.

FIG. 1 is a conceptual diagram showing an embodiment of a greenhouse cultivation system of the present invention. FIG. 2 is a perspective view showing the configuration of the heat exchange / heat accumulator. Fig.3 (a) is sectional drawing which shows an example of the structure of the heat exchanger and heat storage under a cultivation bed, (b) is the enlarged view which showed the structure of the dew condensation toy vicinity. FIG. 4 is a diagram showing a part of an aspect in which an underground heat storage unit is provided in addition to the heat exchanger / heat storage provided under the cultivation bed. FIG. 5 is a cross-sectional view showing an example of the structure of the heat exchanger / heat accumulator under the cultivation bed and the underground heat storage section. FIG. 6 is a diagram showing a process of controlling the cultivation environment in one day of the greenhouse cultivation system of the embodiment. Drawing 7 is a figure for explaining an example of the cultivation environment control method through the year of the cultivation system for greenhouses of the above-mentioned embodiment. FIGS. 8A and 8B are views showing a mode in which the heat pump is installed outside the greenhouse.

  Hereinafter, although the embodiment of the cultivation system for greenhouses of the present invention is described, the present invention is not limited to the following embodiments.

  As shown in the embodiment of FIG. 1, the greenhouse cultivation system 1 of the present embodiment is provided inside a greenhouse 10. For example, the greenhouse 10 is made of a steel material and has an outer wall covered with a synthetic resin film or glass. The greenhouse 10 is provided with a skylight, a side window, and the like, and can be ventilated by opening and closing the skylight.

A cultivation bed 20 is provided in the greenhouse 10. In this embodiment, as shown in FIG. 3, the cultivation bed 20 is supported on the mount 21 installed at a height of about 1 to 1.5 m from the ground. The gantry 21 includes a pair of leg members 21a and 21b arranged with a predetermined interval in the width direction of the heat exchanger / heat accumulator 30 so as to sandwich a heat exchanger / heat accumulator 30 to be described later. And a beam member 21c spanned between the members 21a and 21b, and these are provided at predetermined intervals in the longitudinal direction of the heat exchanger / heat accumulator 30. The beam member 21c is formed in a substantially U-shaped cross section, and a hole portion is provided in the vicinity of each end portion of each of the plate portions facing each other in the vertical direction, and the leg members 21a and 21b are provided in the hole portions. Is inserted. Since the gantry 21 has such a configuration, when the construction is performed, the beam member 21c is positioned on the ground as a ruler, and the leg members 21a and 21b are inserted into the holes and driven. 21c is shifted upward and the beam member 21c is set horizontally using a level (not shown). As a result, the leg members 21a and 21b can be erected vertically, so that the leg members 21a and 21b can be easily constructed, and the beam member 21c has a substantially U-shaped cross section. The cultivation bed 20 is placed along the longitudinal direction on the beam member 21c of the gantry 21 arranged in this way. Such a so-called elevated bed has the merit that the posture of the operator becomes easy, and the gantry 21 of the present embodiment has the simple configuration as described above, but is distorted or bent due to the weight of the cultivation bed 20. Such deformation is not likely to occur.

  The cultivation bed 20 may be suspended and supported in the greenhouse 10 so as to have a predetermined height from the ground. Further, as proposed in Japanese Patent Application Laid-Open No. 2004-254688 by the present applicant, the cultivation bed 20 may be suspended and supported so as to be movable up and down in consideration of workability, sunshine, and the like.

  The greenhouse cultivation system 1 of this embodiment is provided in the greenhouse 10 having such a cultivation bed 20 and includes a heat exchanger / heat accumulator 30 and a heat pump 50. The heat exchanger / heat accumulator 30 may be installed at any location in the greenhouse 10, but is preferably installed below the cultivation bed 20 installed at a predetermined height as in the present embodiment. In other words, it is preferable to arrange inside the pair of leg members 21a and 21b constituting the mount 21 and below the beam member 21c. By arranging the heat exchanger / heat accumulator 30 below the cultivation bed 20, even if the heat exchanger / heat accumulator 30 is provided, the effective cultivation area in the greenhouse 20 is not reduced, and effective use of the space is intended. Can do.

  As shown in FIG. 3 and FIG. 4A, the heat exchanger / heat accumulator 30 is installed in a lower space of the gantry 21 and is formed in a substantially rectangular cross section filled with a heat accumulator. The heat exchanger / heat accumulator 30 of the present embodiment uses water as a heat accumulator (heat medium). A heat transfer unit is provided on the side surface of the heat exchanger / heat accumulator 30 so as to easily scatter radiant heat. The heat transfer section may be the frame itself constituting the heat exchange / heat accumulator 30, or provided so as to surround the outer surface of the frame separately from the frame constituting the heat exchange / heat accumulator 30. It may be a thing. In this embodiment, the member itself which forms the side surface of the heat exchanger / heat accumulator 30 is configured from a heat transfer plate 32 having a corrugated cross section, and the entire side surface is configured as a heat transfer unit.

The heat exchanger / heat accumulator 30 is preferably formed in a range of 0.3 to 1 m in width, 30 to 50 m in length, and 1 to 1.5 m in height. Accordingly, if about 10 sets per 1000 m ² of the greenhouse area are arranged in parallel, for example, water of 100 t or more can be retained as a whole, and a large heat energy can be secured even with a slight rise in water temperature. Since it is such a shape, the contact area required for heat exchange with the air in a greenhouse can be ensured largely by making two opposing side surfaces into a heat transfer part.

  However, it is preferable that the heat exchanger / heat accumulator 30 is formed with a relationship in which the ratio of the height to the width is greater than 1, that is, with a width that is narrower than the height. When the width is narrower, natural convection of water as a heat storage body is likely to occur, the water temperature is equalized without unevenness, and the heat exchange efficiency is increased.

  The heat transfer plate 32 is preferably formed in a cross-sectional wave shape, whereby a larger contact area required for heat exchange with the air in the greenhouse can be ensured. In this case, the heat transfer plate 32 is arranged in such a direction that each mountain and valley portion is substantially horizontal to the floor surface (ground). As described above, a large amount of water is retained inside, but by arranging in such a direction, deformation of the heat transfer plate due to water pressure is suppressed.

  The heat transfer plate 32 preferably has a thermal conductivity in the range of 50 W / (mk) to 300 W / (mk). The heat exchanger / heat accumulator 30 can promote heat exchange between the air in the greenhouse and the heat storage body, and needs to balance heat storage for nighttime heating. Heat exchange with the internal air is difficult to be performed, and if it exceeds this range, the heat retention efficiency is lowered. Considering the balance between heat exchange efficiency and heat retention efficiency, the thermal conductivity is more preferably in the range of 60 W / (mk) to 100 W / (mk), and in the range of 70 W / (mk) to 90 W / (mk). Further preferred. Examples of the heat transfer plate 32 having a thermal conductivity in the above range include a plate member having a thickness of 0.25 to 1.5 mm made of an iron plate or an aluminum plate. However, an iron plate having a thickness of 0.25 to 0.8 mm is preferable in consideration of cost in addition to prevention of deformation due to water pressure.

  Further, when the heat transfer plate 32 is made of an iron plate having a thickness of 0.25 to 0.8 mm, in order to give a desired water pressure resistance, the interval between the apexes of adjacent peaks in the mountain valley is 30 to 80 mm, What was formed in the range whose distance of the vertex of a mountain part and the vertex (valley bottom) of a trough part is 7-20 mm is preferable.

  The heat exchanger / heat accumulator 30 is formed so as to be surrounded by a side surface constituted by the heat transfer plate 32 and end wall members 35 provided at both ends in the longitudinal direction, and the inner surface of the heat transfer plate 32, the end wall member 35. The inner surface of the sheet and the ground located between the heat transfer plates 32 are covered with a plastic sheet, and water as a heat storage body is filled inside the plastic sheet. Therefore, the bottom surface 36 of the heat exchanger / heat accumulator 30 is formed by a plastic sheet located on the ground. Since the bottom surface 36 is a plastic sheet, the heat conductivity is high, and heat exchange with the underground heat storage unit 60 described later is promoted. That is, in the present embodiment, the bottom surface 36 also constitutes a heat transfer unit.

  Further, a dew condensation toy 40 is disposed along the side surface of the heat exchanger / heat accumulator 30 below the heat transfer plate 32 forming the side surface of the heat exchanger / heat accumulator 30 (see FIG. 3B). . When the surface temperature of the heat transfer plate 32 becomes equal to or lower than the dew point temperature of the air, the water vapor is condensed. Re-evaporation can be prevented and condensed water can be reused.

  The heat transfer part is preferably provided on at least the side surface (heat transfer plate 32) of the heat exchanger / heat accumulator 30, but not limited to this, the bottom surface 36 can be configured as the heat transfer part as described above. The upper surface of the heat exchanger / heat accumulator 30 can also be configured as a heat transfer section. In the case where the side surface or the upper surface is a heat transfer section, it becomes easy to cause radiant heat to act on the crop of the cultivation bed 20 on the upper side.

A reflection sheet 33 that covers the heat transfer plate 32 is provided outside the heat transfer plate 32. For example, a winding shaft 33a disposed substantially in parallel with the heat exchanger / heat accumulator 30 is provided on the side of the beam member 21c constituting the gantry 21, and the upper edge of the reflection sheet 33 is wound around the winding shaft 33a. By rotating the winding shaft 33a to wind or rewind, the winding shaft 33a can be opened and closed in the vertical direction. When the side surface of the heat exchanger / regenerator 30 is covered with the reflection sheet 33, the temperature of the water in the heat exchanger / regenerator 30 is suddenly increased by sunlight, or excessive radiation from the heat exchanger / regenerator 30 is generated. Can be suppressed.

  A blower conduit 70 is provided between the heat transfer plate 32 and the reflection sheet 33. The blower conduit 70 is preferably connected to a carbon dioxide generator (not shown) and supplies carbon dioxide by driving a blower fan (not shown). Carbon dioxide is guided to the cultivation bed 20 side through the gap between the heat transfer plate 32 and the reflection sheet 33 by keeping the reflection sheet 33 in a closed state (a state in which the side surface of the heat exchanger / heat accumulator 30 is covered). Therefore, it is possible to maintain the carbon dioxide concentration in the vicinity of the crop at a higher concentration than the atmospheric concentration. The carbon dioxide concentration is preferably 2 to 4 times the atmospheric concentration. In addition, by providing a blower fan, the heat transfer of the heat transfer plate 32 is promoted, and condensation is generated on the heat transfer plate 32 in a high temperature and high humidity state, thereby contributing to the creation of an optimum crop environment.

  The heat pump 50 incorporated in the greenhouse cultivation system 1 of this embodiment as another heat collecting device in the greenhouse uses room air as a low-temperature heat source, and water that is a heat storage body (heat medium) of the heat exchanger / heat accumulator 30. It is characterized by a high temperature side heat source. The heat exchanging unit 30 and the heat exchanging unit 53 of the heat pump 50 are connected by a pipe 51, and the inside of the greenhouse is cooled during the heat pump heat collecting operation during the daytime, and the removed heat is stored in the heat exchanging unit 30. . In this embodiment, water that is a heat storage body of the heat exchanger / heat accumulator 30 circulates in the pipe 51, but the loop 51 brine pipe that passes through the pipe 51 is passed through the heat exchanger / heat accumulator 30. The heat medium (water) in the brine pipe is heated in the heat exchanger 53, and the heat is transmitted to the heat storage body (water) in the heat exchanger / heat accumulator 30. is there.

  The greenhouse 10 inherently has a high function of converting solar energy into heat, and surplus heat exceeding a set temperature is generated during the day. Usually, the surplus heat is discharged from the ventilation window to discharge the greenhouse. The air in 10 is ventilated to suppress an excessive temperature rise. On the other hand, in this embodiment, the heat exchanger / heat accumulator 30 naturally collects heat until the set temperature is reached, and surplus heat that exceeds the set temperature is discharged by ventilation by operating the heat pump 50 to cool. Excess heat is collected by the heat pump 50, and this heat is further stored in the heat storage body (water) of the heat exchanger / heat accumulator 30 via the heat pump 50. In the night when heating is required, the heat is exchanged by natural heat radiation from the heat exchanger / heat accumulator 30, and when necessary, the heat pump 50 is operated to extract heat from the heat exchanger / heat accumulator 30, and from the heat pump 50 Warm air is introduced into the greenhouse 10 for heating. Especially in nighttime heating, the heat storage body (water) in the heat exchanger / heat accumulator 30 is the heat source of the heat pump 50. Therefore, the heating performance declines due to frost formation of an evaporator such as a heat pump that uses air outside the greenhouse as a heat source. There is no need for inefficient defrosting operation of the heat pump. An increase in the nighttime heating load inevitably results in a decrease in the temperature of the heat storage body (water). This temperature drop increases the heat drop between the heat transfer surface temperature of the heat transfer plate 32 of the heat transfer plate 32 and the ambient air temperature in the case of sunny weather the next day, increases the amount of heat collection, and reduces the burden on the heat pump. It becomes a linked effect. In addition, according to experiment of this inventor, since the heat storage / heat accumulator 30 and the heat storage body (water) of the heat pump 50 are shared and linked, the ratio of the energy input to the system and the energy acquired by the system The coefficient of performance was remarkably improved compared to the case where each element was operated alone. The actual operation performance coefficient data was about 11, compared with 5 for the operation with only the heat pump.

  Since the greenhouse cultivation system 1 of the present embodiment uses the heat exchanger / heat accumulator 30 and the heat pump 50, the electrical energy required for cooling and heating the greenhouse 10 can be extremely reduced, thus saving energy. Even if the ventilation window is opened and the temperature in the greenhouse 10 is lowered by ventilation, the timing for opening the ventilation window etc. is delayed, the total opening time is shortened, Depending on the winter season, it can be completely closed throughout the day. As a result, the carbon dioxide concentration and humidity in the greenhouse required for photosynthesis can be maintained higher than the atmospheric concentration, and the invasion of pests through ventilation windows, etc. will be reduced, and the quality and yield of crops will be improved. be able to.

  Moreover, in this embodiment, the heat exchanger / heat accumulator 30 is disposed below the cultivation bed 20 as described above. For this reason, the radiation and convection heat of the heat transfer plate 32 are likely to act on the crop. In particular, if the reflection sheet 33 is in a closed state, the radiation and convection heat of the heat transfer plate 32 can be easily applied to the crops grown on the cultivation bed 20 located above the heat exchanger / heat accumulator 30. As a result, for example, in winter nights, even if the entire greenhouse 10 does not reach a predetermined temperature, the temperature of the crop and its surroundings can be directly controlled. Therefore, heat exchange / heat storage provided with the heat transfer plate 32 of the present embodiment. Use of the vessel 30 is preferable in terms of energy saving, and further contributes to achievement of high quality crops and high yields.

  As shown in FIGS. 4 and 5, the greenhouse cultivation system 1 of the present embodiment preferably has a configuration in which an underground heat storage unit 60 is provided in addition to the heat exchanger / heat storage unit 30. Since there is a limit to the installation space in the lower space of the cultivation bed 20 where the heat exchanger / heat accumulator 30 is arranged, when only the amount of heat stored in the heat exchanger / heat accumulator 30 is insufficient in capacity, as in this embodiment It is preferable to provide the underground heat storage unit 60 in the ground. In addition, when storing the heat collected by cooling in summer, it is suitable to store the heat in the underground heat storage unit 60 so that the heat does not act on the crop.

  Although the underground heat storage unit 60 can be provided outside the floor surface of the greenhouse 10 (the range of the installation area of the greenhouse 10), the heat pump 50 is installed in the greenhouse 10, and the arrangement position of the piping 51, etc. Is preferably provided in the floor of the greenhouse 10, and in the embodiment shown in FIGS. 4 and 5, it is provided directly below the heat exchanger / heat accumulator 30. When it is provided in the floor surface of the greenhouse 10, there is also an advantage that heat radiation from the underground heat storage unit 60 to the greenhouse 10 can be naturally applied. Moreover, in this embodiment, the bottom face 36 of the heat exchanger / heat accumulator 30 is formed of a plastic sheet having a high thermal conductivity, and the bottom face 36 also constitutes a heat transfer section. Therefore, if the underground heat storage part 60 is provided directly under the heat exchange / heat storage 30, heat exchange between the two can be promoted. For this reason, the heat stored in the underground heat storage unit 60 can be collected by the heat storage body of the heat exchanger / heat storage 30 and used for nighttime heating or the like.

  Moreover, although the heat exchanger / heat accumulator 30 is used for heat storage in the daytime and nighttime as described above, the underground heat storage section 60 is in a longer cycle (for example, weekly). Heat storage is also possible. As the underground heat storage unit 60, the soil heat storage method is adopted in this embodiment. Soil heat storage is solid sensible heat storage using soil (ground) as a heat storage body. The ground is a semi-infinite continuous solid and may be used as it is, or a method of limiting the heat storage range by providing a heat insulating enclosure may be employed. In the present embodiment, a brine pipe 52 is connected to the heat pump 50, the brine pipe 52 is disposed directly below the heat exchanger / heat accumulator 30, and the heat medium (water) in the brine pipe 52 and the surrounding soil Heat exchange between the two. Of course, the heat storage method is not limited, and a water tank may be provided in the basement to store heat in water. However, the soil heat storage system is suitable from the viewpoint of cost. In addition, the brine pipe 52 for the underground heat storage unit 60 is connected to the pipe 51 for the heat exchange / heat storage unit 30 via the switching valve 55.

  The switching valve 55 determines whether the heat collected by the heat pump 50 is stored in either the heat exchanger / heat storage 30 or the underground heat storage unit 60. For example, the heat collected by the heat pump 50 is stored in the heat exchanger / heat accumulator 30 until it reaches a predetermined temperature, and when it exceeds the predetermined temperature, the underground heat storage unit 60 is switched to store the heat. When the inside of the greenhouse 10 is heated by the heat pump 50, the heat of the heat exchanger / heat accumulator 30 is released until the water temperature of the heat exchanger / heat accumulator 30 reaches a predetermined temperature. It switches so that the heat | fever of the middle heat storage part 60 may be discharge | released. The switching valve 55 can be operated manually, but the temperature in the greenhouse 10, the temperature of the heat storage body (water) of the heat exchanger / heat storage 30, and the temperature of the heat storage body of the underground heat storage unit 60. It is also possible to perform computer management that measures and automatically switches based on these temperatures.

  An example of the cultivation environment control method by the greenhouse cultivation system 1 of this embodiment is demonstrated based on FIG. First, as a premise, it is assumed that the cooling operation start temperature by the heat pump 50 is set to, for example, room temperature 25 ° C. In this state, during the daytime, heat exchange with the air in the greenhouse (passive heat collection) is performed through the heat transfer plate 32 of the heat exchanger / heat accumulator 30 until the room temperature reaches 25 ° C. Heat is collected. Although the heat storage body gradually rises in water temperature, this passive heat collection makes the room temperature increase rate slower than when the heat exchanger / heat storage unit 30 is not installed. If the room temperature exceeds 25 ° C., the heat pump 50 starts cooling operation, collects heat (active heat collection), and controls to keep the room temperature at 25 ° C. as much as possible. The heat collected by the heat pump 50 is stored in the heat storage body of the heat exchanger / heat accumulator 30, and the water temperature of the heat storage body further rises.

  When the room temperature falls below 25 ° C., the cooling operation of the heat pump 50 is stopped. At night, when the room temperature falls below the water temperature of the heat storage body of the heat exchanger / heat accumulator 30, the heat stored in the heat storage body is dissipated through the heat transfer plate 32 (passive heat dissipation). Thereby, the fall rate of room temperature becomes slower than the case where the heat exchanger / heat accumulator 30 is not installed. When the room temperature falls below a preset heating operation start temperature (for example, 15 ° C.) by the heat pump 50, the heating operation by the heat pump 50 is started, heat is drawn from the heat exchanger / heat accumulator 30, and warm air is drawn from the heat pump 50 into the greenhouse 10. Release and heat (active heat dissipation). As a result, the room temperature is maintained at a predetermined temperature. Due to the active heat radiation, the water temperature of the heat storage body further decreases (water temperature at which Δt in FIG. 6 is lowered due to the active heat radiation). As a result of this temperature drop Δt, as described above, an increase in the amount of heat collected due to the heat drop between the heat transfer surface temperature of the heat transfer plate 32 of the heat exchanger / heat accumulator 30 and the ambient air temperature is caused, and the burden on the heat pump 50 is reduced. cut back.

  As described above, when the room temperature is controlled in the range of the predetermined temperature by the cooling operation by the heat pump 50 during the day, ventilation during the day is not necessary. Thereby, since closed cultivation can be performed, by supplying carbon dioxide, the carbon dioxide concentration in the greenhouse 10 can be maintained higher than the carbon dioxide concentration in the atmosphere, and the invasion of pests from skylights is reduced, Increase crop quality and yield.

  On the other hand, if the room temperature cannot be controlled to a predetermined temperature (for example, 30 ° C.) even when the heat pump 50 is operated, if the predetermined temperature is exceeded, the skylight is opened to perform ventilation. According to the present embodiment, even when such ventilation is performed, as described above, room temperature control is performed by heat exchange by the heat exchange / heat accumulator 30, and then the heat pump 50 is operated. It is the structure which ventilates only when it cannot control below, and can achieve what is called a semi-closed type cultivation environment with less ventilation time compared with the past.

  FIG. 7 is a diagram showing a specific example of control throughout the year when the indoor environment of the greenhouse is controlled using the greenhouse cultivation system 1 of the present embodiment. For example, in the hot season from early June to early July to late September to mid-October, the temperature cannot be controlled by air conditioning alone during the daytime. Combined. First, the room temperature is lowered by heat exchange by the heat exchanger / heat accumulator 30, and when the temperature becomes equal to or higher than a predetermined temperature, the refrigerant of the heat pump 50 is exchanged with the water on the brine pipe 52 side through the heat exchanger 53. Control switching. Thereby, when the heat pump 50 is operated and cooled, the heat collected by the cooling is stored in the underground heat storage unit 60. In the case of crops such as strawberries, cool at night during this season. Therefore, the cooling is operated at night. In order to efficiently perform night cooling, it is preferable that the temperature of the heat storage body of the heat exchanger / heat storage 30 is not increased during the day. Therefore, heat collected with the cooling of the heat pump 50 during the day is preferentially stored in the underground heat storage unit 60. When the nighttime cooling is operated, the heat exchanger / heat accumulator 30 itself is also cooled, so that the water temperature decreases and the surface temperature of the heat transfer plate 32 also decreases. When the surface temperature of the heat transfer plate 32 is lowered, the crop of the cultivation bed 20 disposed immediately above the heat exchanger / heat accumulator 30 is also cooled by radiation and convection heat. Therefore, the night cooling effect can be enhanced. Moreover, since the crop can be cooled directly by the radiation of the heat transfer plate 32, the operating time of the heat pump 50 for cooling the entire greenhouse 10 can be shortened, or the control temperature can be made lower than the night cooling control temperature conventionally performed. It can be set higher, which contributes to energy saving. In addition, the same effect as described above can be obtained by replacing the water filled in the heat exchanger / heat accumulator 30 with groundwater having a low water temperature. Moreover, when the surface temperature of the heat transfer plate 32 of the heat exchanger / heat accumulator 30 is lower than the dew point temperature, the water vapor is condensed on the surface of the heat transfer plate 32, the water flows down to the dew condensation tray 40, and the water is recovered. Can be reused. Note that the heat stored in the underground heat storage unit 60 can be used as a heat source for heating as necessary, such as when the temperature becomes abnormally low, even in this season.

  On the other hand, in the cold season from mid-October to late June, the following control is performed. First of all, during the daytime, the greenhouse 10 has a high function to convert solar energy into heat, and the room temperature becomes considerably high even in this season, so especially in mid-October to late November and from early March to late June. , There will be times when you have to ventilate the skylight.

  However, in the morning, first, the heat in the greenhouse 10 is collected by the heat accumulator by heat exchange by the heat exchanger / heat accumulator 30, and when the temperature exceeds a predetermined temperature, the heat pump 50 is operated to collect excess heat in the greenhouse 10. And heat is stored in the heat exchanger / heat accumulator 30. When the heat capacity of the heat exchanger / heat accumulator 30 is insufficient, specifically, when the temperature of the heat exchanger / heat accumulator 30 exceeds a certain temperature (for example, 25 ° C.), the pipe 51 is changed to the brine pipe 52. The underground heat storage unit 60 stores heat by switching the flow path of the heat medium. In this way, the inside of the greenhouse 10 is cooled, and heat is stored in the heat exchanger / heat accumulator 30 and the underground heat storage section 60, thereby opening the skylight and the like and delaying the time to start ventilation. Accordingly, the time during which carbon dioxide is actively supplied and the carbon dioxide concentration in the greenhouse 10 is maintained higher than the carbon dioxide concentration in the atmosphere (preferably twice to four times that in the air), The time for maintaining the humidity can be made longer than before.

  On the other hand, at night, the inside of the greenhouse 10 is heated by natural heat radiation from the heat transfer plate 32 of the heat exchanger / heat accumulator 30. When the room temperature falls below the set temperature, the heat pump 50 is operated. The heat source of the heat pump 50 uses the heat stored in the heat exchanger / heat accumulator 30 or the underground heat storage section 60 and releases this heat into the greenhouse 10 to heat the inside of the greenhouse 10. Since the heat stored in the heat exchanger / heat accumulator 30 or the underground heat storage section 60 is used, the amount of electric energy consumed by the heat pump 50 can be extremely low. In addition, the crop is directly warmed by the radiant heat of the heat transfer plate 32 of the heat exchanger / heat accumulator 30. Therefore, even if the temperature at the time of heating the whole greenhouse 10 is lower than before, it is possible to obtain a temperature environment sufficient for crops. From this point also, the electric energy consumption of the heat pump 50 should be further reduced. Can do.

  Moreover, in the coldest season from early December to late February, it is possible to prevent ventilation at all during the day by collecting heat by heat exchange by the heat exchanger / heat accumulator 30 and cooling by the heat pump 50. it can. As a result, in the coldest season from early December to late February, carbon dioxide is actively supplied, so that the carbon dioxide concentration in the greenhouse 10 can be maintained even during sunshine hours when the photosynthesis of the crop is active. It will be maintained at a higher concentration than the atmospheric concentration.

  That is, according to this embodiment, the coldest period from the beginning of December to the end of February can be cultivated in a closed environment in which ventilation is not performed at all during the day as well as at night, and the period before and after that period is from mid-October to In late November and early March to late June, it can be cultivated in a semi-closed environment with a shorter ventilation time than before, thereby maintaining the carbon dioxide concentration required for photosynthesis at a higher concentration than the atmospheric concentration. However, the invasion of pests from the skylight is reduced, and the crop quality and yield can be increased.

  In the above embodiment, not only the heat exchanger / regenerator 30 but also the heat pump 50 is provided in the greenhouse 10. Thereby, since the heat in the greenhouse 10 can be pumped and heat exchange can be performed, it is excellent in terms of heat exchange efficiency. However, although it is inferior in terms of heat exchange efficiency, for example, as shown in FIG. 8A, the heat pump 50 is installed outside the greenhouse 10, and the air blower 50 a is connected to the greenhouse 10 for cooling. You can also. A pipe 51 is provided between the heat exchanger / heat accumulator 30 and the heat exchanging part of the heat pump 50 so that the heat accumulator (water) can pass therethrough. In this case, the heat pump 50 collects outside air, applies heat to the water in the pipe 51, and supplies cold air into the greenhouse 10 from the blower 50 a.

  Further, as shown in FIG. 8B, the heat pump 50 can be installed outside the greenhouse 10, and not only the air blowing unit 50 a but also the heat collecting unit 50 b can be connected to the greenhouse 10. In this case, since the heat in the greenhouse 10 is pumped up through the heat collecting unit 50b, the heat exchange efficiency is the same as that of the above embodiment, but the air blowing unit 50a, the heat collecting unit 50b, and the greenhouse The equipment cost etc. accompanying the connection with 10 increase compared with the said embodiment.

  Since the greenhouse cultivation system of the present invention can cool and heat the greenhouse with energy saving, it can be used in the field of horticulture that produces crops with high profitability.

DESCRIPTION OF SYMBOLS 1 Greenhouse cultivation system 10 Greenhouse 20 Cultivation bed 30 Heat exchange / heat accumulator 32 Heat transfer plate 33 Reflective sheet 50 Heat pump 51 Piping 52 Brine pipe 60 Underground heat storage part 70 Air duct

Claims (11)

A heat exchange / heat accumulator having a substantially square cross section, which is disposed in the greenhouse and has a heat transfer section at least on the side surface for promoting heat exchange between the air in the greenhouse and the heat accumulator filled in the interior;
A heat pump for transferring heat to the heat storage body in the heat exchanger / heat accumulator;
The heat transfer part is composed of a corrugated iron plate having a thickness of 0.25 to 0.8 mm, and each mountain and valley part is composed of a heat transfer plate arranged in a direction substantially horizontal to the floor surface. Greenhouse cultivation system.   The greenhouse cultivation system according to claim 1, wherein the heat pump is installed in a greenhouse. The greenhouse system according to claim 1 or 2 , wherein the heat transfer section is formed of a material having a thermal conductivity in the range of 50 W / (mk) to 300 W / (mk). Said heat exchanger-regenerator, greenhouse cultivation system according to any one ratio of height to its section width is greater than one claim 1-3 1. The greenhouse cultivation system according to any one of claims 1 to 4 , wherein the heat exchanger / regenerator is provided in the greenhouse below a cultivation bed located at a predetermined height from the ground surface. The heat exchanger / heat accumulator is disposed inside the pair of leg members disposed at a predetermined interval in the cross-sectional width direction, and is between the pair of leg members, the heat exchanger / heat accumulator. The greenhouse cultivation system according to claim 5 , wherein a beam member is horizontally stretched above and the cultivation bed is supported on the horizontally stretched beam member. The greenhouse cultivation system according to any one of claims 1 to 6, wherein a reflection sheet capable of covering a heat transfer portion located on a side surface of the heat exchanger / heat accumulator is provided. The cultivation system for greenhouses of Claim 7 with which the said reflection sheet is provided so that opening and closing is possible so that it may be in the state which covered the said heat-transfer part, and the state which is not covered in the position spaced apart from the said heat-transfer part. . The greenhouse cultivation system according to claim 7 or 8, wherein a blower conduit capable of supplying carbon dioxide is provided between the heat exchanger / heat accumulator and the reflection sheet. The greenhouse cultivation system according to any one of claims 1 to 9 , wherein an underground heat storage unit is provided in the ground in the greenhouse. The greenhouse heat cultivation system according to claim 10, wherein the heat exchanger / heat accumulator is provided with a bottom surface in contact with the ground, and the bottom surface constitutes a heat transfer section capable of exchanging heat with the underground heat storage section. .

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