JPH0532005B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a greenhouse cultivation chamber used for plant cultivation.

<Prior art and its problems> When cultivating plants, so-called open field cultivation, in which plants are exposed directly to outside air, has a limited growing season in response to changes in temperature due to seasonal changes. For this reason, the roof and exterior walls of steel structures are covered with transparent materials such as vinyl sheets, allowing the light needed for plant growth to reach them, but keeping the outside air out and controlling the indoor temperature to reduce the influence of outside air. Plastic greenhouses and the like are widely used. With the spread of vinyl greenhouses, it has become possible to grow plants to match their germination and growth periods to the shipping time, and it has become possible to grow tropical plants that cannot be grown in open fields. It is useful for enriching one's diet. In such greenhouse cultivation, when raising the temperature inside the greenhouse above the outside air, it is common practice to directly heat the greenhouse with kerosene and use the heat of the exhaust gas and radiant heat. Although this method has relatively low equipment costs, it uses expensive kerosene and therefore has high operating costs. On the other hand, when using geothermal heat or waste heat from factories to raise the temperature inside the greenhouse, this heat is usually obtained in the form of steam or hot water, so the heat medium is transferred to a finned tube installed inside the greenhouse. It is carried out by circulating it through a type heat exchanger. Although this method has low operating costs, the equipment costs are high and the locations where such heat can be obtained are very limited. On the other hand, when cooling the inside of a greenhouse to slow the growth of plants or to harvest fruits that can only be obtained in the cool season of midsummer, electric heat pump cooling equipment, which is normally used in buildings, may be used. This is possible, but greenhouses cannot block sunlight due to the growth of plants, and solar heat (infrared rays) also comes in with the sunlight, so a greenhouse with extremely high cooling capacity must be used. , impractical in terms of equipment and operating costs (mainly electricity charges). Another option is to spray water inside the greenhouse to lower the temperature.
Water droplets attached to plants become warm water due to solar heat,
May be harmful to plants.

Therefore, it is possible to cool the inside of a greenhouse only when a large amount of low-temperature groundwater is available. Just do it.

As mentioned above, each conventional house air conditioner has its own problems, and it has not been possible to raise and cool the temperature with the same device.

<Object of the Invention> The present invention was devised in view of the problems of the prior art, and provides a greenhouse cultivation room in which the indoor temperature can be controlled according to the growth of plants with relatively low equipment and operating costs. The purpose is to provide

<Means for Solving the Problems> In order to achieve the above object, the greenhouse cultivation room of the present invention has a space covered with a transparent member, and in the greenhouse cultivation room in which plants are cultivated in the space, indoor As a means for air conditioning, a water sprinkling device is installed on the top, and water is allowed to flow from the water sprinkling device onto the surface of the wet element, which is made up of a number of plate-shaped members having unevenness arranged in the vertical direction at required intervals. A wet wall heat exchanger is installed between the wet elements to exchange heat between water and air by circulating air along the surface of the plate member, and a water receiving tank is installed at the bottom. The system is also characterized by the installation of a pump for circulating water from the water tank to the sprinkler system.

<Example> Figure 1 is a combination of a sectional view and a piping system diagram of a greenhouse cultivation room according to the present invention, and Figure 2 is a diagram of a wet wall heat exchanger used in the greenhouse cultivation room of the present invention. FIG.

First, the configuration will be explained with reference to FIGS. 1 and 2. The greenhouse cultivation room 1 has a steel frame structure, and the roof and side walls are covered with transparent materials such as glass or vinyl sheets.A shelf is provided in the internal space 12, and the plants 2
are cultivated.

A wet wall heat exchanger 3 is provided near the side wall of the greenhouse cultivation room. Water used in the wet wall heat exchanger 3 flows into a water tank 4 provided at a lower position than the heat exchanger 3, and is sent back to the heat exchanger 3 by a water pump 5 for circulation. A cross-flow type wet wall heat exchanger 3 is shown in FIG. 2, and has the following configuration. That is, the heat exchanger 3
includes an upper water sprinkler 21, an intermediate wet element 22, a lower water tank 23, and a casing 27.
and ventilation fan 26.

The watering device 21 consists of a horizontal pipe 21a with a large number of small holes in the upper part, and an arcuate reflecting plate 21b installed above the pipe 21a and extending in the horizontal direction. The jetted water is dispersed by a reflecting plate 21, and water droplets fall in the form of rain. The wet element 22 provided below the water sprinkling device 21 is an assembly made up of a large number of uneven plastic plate members that are arranged in the vertical direction and are partially joined together.
The water droplets falling from the plate-like member flow down while wetting the entire surface of the plate-shaped member. The flowing water is received by a water receiving tank 23 provided below the wet type element 22. The entire surface except the lower part of the water sprinkler 21 and the wet element 22
The air outflow side side is covered with an upper casing 27a and a lower casing 27b, respectively, and the lower casing 27b has a large number of fans 26.
is provided, and sucks air from the side of the wet element 22 through the gap between the plate-like members constituting the wet element 22, and discharges the passed air to the side.

Returning to FIG. 1 again, the water that has flowed down into the water tank 23 of the wet wall heat exchanger 3 flows into the water tank 4 located at a lower position than the water tank, and is pumped by the water pump 5 into the water tank 23 of the wet wall heat exchanger 3. The water is sent to the water sprinkler 21 of the exchanger 3. The water tank 4 is provided with a heating coil 4a, and by passing steam through it, the water temperature in the tank can be heated. The indoor temperature can be adjusted by detecting the temperature inside the greenhouse cultivation room and guiding it to the temperature controller 4b, which then adjusts the control valve 4e provided on the steam inflow side of the heating coil 4a. ing. Note that the water tank 4 is provided with a make-up water pipe 4b,
The water level in the water tank 4 is kept constant. A louver type opening/closing damper 9a is provided on the side wall of the greenhouse cultivation room 1 facing the suction side of the wet wall heat exchanger 3 for suctioning outside air, and the opposite side wall facing the side wall is also provided with a damper 9a for sucking outside air. Galari type opening/closing damper 9 for discharge
b is provided. An air damper 10 is provided below the wet wall heat exchanger 3, and controls the circulation of air within the greenhouse cultivation room 1.

Next, the operation will be explained with reference to FIG.

First, a case will be described in which the temperature is higher than the temperature suitable for the required stage of growth of the plants being cultivated and the indoor temperature is lowered.

In this case, the louver type opening/closing dampers 9a and 9b are kept open, and the air damper 10 is kept closed. Also, water is circulated between the wet wall heat exchanger 3 and the water tank 4, and the water is allowed to flow down to the wet element 22. When the fan 26 is operated in this state, outside air flows in through the louver type opening/closing damper 9a. , passes through the wet element 22 and is sucked into the fan 26,
It flows out into the room, blows through the room, and flows out through the louver type opening/closing damper 9b.

Here, changes in the state of the air passing through the wet element 22 will be explained. FIG. 3 is a hygrodynamic diagram showing the relationship between temperature t (° C.) and absolute humidity x' (Kg of water vapor/Kg of dry air), and the curve ab represents the saturated air curve. The temperature and humidity of the outside air are now X(t ₁
x ₁ ), when the air passes through the wet element 22, it comes into contact with the flowing water and takes away the heat of evaporation, causing the temperature of the air to drop, but on the humid psychrometric diagram, this is an isenthalpic change. Change, X
The isenthalpic curve passing through the point and the saturated economic curve ab
Let the intersection point be the Z (t ₂ x ₂ ) point (t ₂ corresponds to the wet bulb temperature of the outside air), then the air changes along the X-Z line to the Y (T ₃ x ₃ ) point, which is close to the Z point. . That is, the air comes into contact with water, increasing the humidity and lowering the temperature to near the wet bulb temperature of the outside air. On the other hand, water also gets wet.Wall type heat exchanger 3
The latent heat of evaporation is taken away from the water, and while it circulates between the water tank and the water tank, the temperature also drops to around the wet bulb temperature of the outside air. The air cooled by the wet wall heat exchanger 3 blows through the room, lowering the room temperature. The indoor temperature is controlled by increasing or decreasing the number of operating fans 26 or by changing the rotation speed.

However, the cooling limit for indoor temperature is the wet bulb temperature of the outside air. Even in the relatively humid suburbs of Tokyo, during the day when the temperature is high, the difference between the dry bulb temperature (air temperature) and the wet bulb temperature is 5 to 10 degrees Celsius, so the cooling effect of the present invention is sufficient. The effect is even greater.

Next, a case where the device is used as a heater to raise the indoor temperature will be explained.

In this case, the louver type opening/closing dampers 9a and 9b are closed and the air damper 10 is left open. Also, water is circulated between the wet wall heat exchanger and the water tank 4 to flow down to the wet element 22. Also, water is heated by flowing steam through the heating coil 4a in the water tank. If you drive the fan 26 in this condition,
Indoor air flows in through the air damper 10, passes through the wet element 22, comes into contact with the flowing hot water, and is heated up, is then sucked into the fan 26, flows out into the room, and then passes through the room to become air again. Return to damper 10 and repeat the same process. That is, indoor air circulates indoors centering around the wet wall heat exchanger 3. As a result, the indoor air is almost saturated air, and it does not absorb much of the latent heat of evaporation as in the case of cooling mentioned above, so the heat of the hot water is mostly consumed by increasing the sensible heat of the indoor air. Become. Furthermore, when indoor air condenses, latent heat is released, which helps keep the room warm, and evaporation in the wet wall heat exchanger 3 does not result in heat loss.

If a large amount of heat is obtained in the form of hot water, such as from heated waste water from a factory, it is sufficient to receive the heat in the water tank 4, send it to the wet wall heat exchanger 3, and then drain the water that has passed through it to the waste water.

<Modifications> The present invention is not limited to the steam embodiment, and the following modifications can be made within the scope of the claims.

(1) As shown in Figure 4, the wet wall heat exchanger 3 is
It may be installed on the above-mentioned side wall, and the air exhaust louver type opening/closing tamper 9b may be attached to the ventilator 30 provided in the center of the roof.

Such an arrangement is effective for relatively large greenhouse cultivation rooms.

(2) As shown in FIG. 5, a wet wall heat exchanger 3 may be installed in the center of the greenhouse cultivation room 1. In this way, indoor air only circulates around the wet wall heat exchanger 3, and outside air is not introduced to the wet wall heat exchanger. Therefore, it can be used for cooling only when cold water such as groundwater is available. The advantage of this system is that the path of the circulating air is shorter than when the wet wall heat exchanger 3 is provided on one side wall, so the temperature distribution inside the room is more uniform.

(3) As shown in FIG. 6, a countercurrent contact type wet wall heat exchanger 3a may be used. In this case Juan 2
6 is provided above the water sprinkler 21, not on the side surface of the wet element 22. Air enters from both sides of the wet element 22, rises within the wet element 22, and is exhausted by the fan 26.

This type of wetted wall heat exchanger is suitable for use in variant (2) mentioned above.

(4) A wet wall heat exchanger of the type in which the fan 26 and lower casing 27b of the wet wall heat exchanger 3 shown in FIG. 2 are removed may be installed as part of the side wall of the greenhouse cultivation room. In this case, after passing natural ventilation such as wind through a wet wall heat exchanger,
The room will be ventilated to cool the room. If the wind blows in a substantially constant direction, it is sufficient to install this wet wall heat exchanger on the windward side wall and leave the leeward side wall completely.
If the direction of the wind is not determined, by installing wet wall heat exchangers on the four side walls, even if the wind blows in that direction, blow-through will occur, so the purpose of cooling will be achieved.

Heating is possible if a large amount of heated wastewater, such as factory wastewater, is available. Furthermore, since no fan 26 is used, there is an advantage that equipment costs and operating costs are lower than in other embodiments.

<Effects of the Invention> As explained above, the greenhouse cultivation room of the present invention is a wet element member made of a large number of plate-shaped members having unevenness arranged in the vertical direction at required intervals for indoor air conditioning. The structure is implemented using a wet wall heat exchanger that allows water to flow down from the water sprinkler onto the surface of the wet element and circulates air along the surface of the plate-like member through the gaps between the wet elements, resulting in the following effects.

(1) Since a single device can cool and heat a room, equipment costs are lower than when installing cooling and heating devices separately.

(2) When cooling the room, the principle of evaporative heat exchange is used, and the latent heat of water evaporation is used to cool the room, so operating costs are low.

(3) Unstable heat sources such as factory waste heat, geothermal water, and geothermal steam, as well as intermittent heat sources such as nighttime electricity, can be widely used, and water has a large specific heat, making it possible to use larger tanks. If you leave it on, its heat storage effect will enable stable heating. These heat sources are usually free or inexpensive, resulting in low operating costs.

(4) Since heat is exchanged through direct contact between air and water, indoor humidity increases, making it suitable for growing plants that prefer high humidity. Also, since the heat transmission coefficient is high,
The equipment becomes more compact and cheaper, and the lighting area can be increased.

(5) Air is circulated along the surface of the plate-shaped members through the wet element, which is made up of a large number of plate-shaped members having unevenness arranged in the vertical direction at required intervals, so that there is little air flow resistance and the air The power cost for the fan is low because of the good flow of water, and the unevenness allows for good air-water contact and active evaporation. There is no performance deterioration due to changes, and stable usage conditions can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a combination of a sectional view and a piping system diagram of a greenhouse cultivation room according to a preferred embodiment of the present invention, Fig. 2 is a perspective view of a wet wall heat exchanger (cross-flow type), and Fig. 3
The figure is a psychrometric diagram showing the relationship between air temperature and absolute humidity, and Figure 4 is a cross-sectional view of a greenhouse cultivation room with wet wall heat exchangers installed on two or more side walls, as a modification of the present invention. FIG. 5 is a cross-sectional view of a greenhouse cultivation chamber in which a wet wall heat exchanger is installed in the center as another modification of the present invention, and FIG. 6 is a perspective view of a countercurrent contact type heat exchanger. 1...House cultivation room, 2...Cultivated plants, 3...
Wet wall heat exchanger, 4... Water tank, 5... Water pump, 9... Galley type opening/closing damper, 10... Air damper, 12... Internal space, 21... Water sprinkler,
22...Wet element, 23...Water tank.

Claims (1)

[Claims] 1. In a greenhouse cultivation room that has a space covered by a transparent member and in which plants are cultivated, a water sprinkler is installed at the top as a means for indoor air conditioning, and water sprinklers are installed at the required intervals in the vertical direction. Water is made to flow down from the sprinkler device onto the surface of a wet element consisting of a large number of plate-like members having arranged unevenness, and heat is exchanged with air between the wet elements along the surface of the plate-like member. A greenhouse cultivation room characterized by having a wet wall heat exchanger installed therein, a water receiving tank at the bottom, and a pump for circulating water.