JPH0677489B2 - Greenhouse heating system - Google Patents

Description

TECHNICAL FIELD The present invention relates to a heating system for greenhouses, and more specifically,
The present invention relates to a heating system at a temperature that stores solar heat and radiates the heat into the greenhouse at night to protect greenhouse crops from low temperature disasters.

<Prior Art> Conventionally, as a greenhouse heating system using solar heat,
For example, a heat storage tank that circulates a heat medium between the heat collector and stores the solar heat collected by the heat collector, and a heat exchange pipe that introduces the heat stored in the heat storage tank to heat the greenhouse are provided. However, there is known a system in which the heat medium of the heat radiation traces is returned to the heat storage tank again (see JP-A-62-40225). Thus, the heating system is superior to the conventional heating system using a heavy oil boiler or the like in that it requires no fuel and is economical and clean.

<Problems to be Solved by the Invention> However, in the above heating system, the heat collection efficiency of the heat collector is constant, and the only heat source is solar heat. On bad days, the disadvantage is that heat collection is less than solar heat. Moreover, the amount of solar radiation fluctuates depending on the season and climate, and the heating temperature also fluctuates accordingly, which is fatal for greenhouse-grown crops that require a relatively high temperature. Become. In such a case, it may be possible to set the capacity of the heat collector according to the condition that requires the most heat, but increase the capacity of the heat collector,
It is necessary to increase the number of heat collectors installed, which is rather expensive because of the high equipment cost.

Also, it has been proposed and implemented to install a clean electric heating underground cable, etc., which enables greenhouse heating at a constant high temperature regardless of weather conditions, but has the drawback of extremely high electricity costs. is there.

In addition, when examining the temperature change in a general greenhouse, the temperature decreases in the early spring and late autumn nights and heating is required, but in the daytime, it rises to a considerably high temperature and heating is required. Not only did it disappear, but there were days when the temperature inside the greenhouse had risen too high and the vinyl sheet covering the greenhouse had to be opened for ventilation cooling.

<Object of the Invention> The present invention has been made in view of the above problems, and improves heat collection efficiency and is excellent in economic efficiency, and enables greenhouse heating under a constant high temperature without being affected by weather conditions. The purpose is to provide a heating system for a greenhouse.

<Means for Solving Problems> As a greenhouse heating system of the present invention for achieving the above object, the solar heat collected by the heat collector is obtained by circulating a heat medium between the heat collector and the heat storage tank. In a heating system that has a heat collection path that stores heat in a heat storage tank and a heat radiation path that releases the heat stored in the heat storage tank to the greenhouse, the buried portion that is drawn into the greenhouse and buried in the ground, and the buried portion. The heat exchange pipe that includes the exposed portion that continuously appears in the greenhouse from the inside, and that circulates the heat medium in the heat storage tank from the buried portion to the heat storage tank through the exposed portion, and the exposed portion of the heat exchange pipe and the heat storage tank. And a medium heating means for heating the heat medium to a predetermined temperature.

<Operation> According to the greenhouse heating system having the above-described configuration, the heat exchange pipe drawn into the greenhouse is temporarily buried in the ground, and is exposed again on the ground surface in the greenhouse.
On a day with a small amount of solar radiation, if the heat medium is circulated not only in the heat collector but also in the heat exchange pipe, solar heat can be collected even at the surface exposed portion of the heat exchange pipe.

Furthermore, even in the underground buried portion of the heat exchange pipe, it is possible to absorb the ground temperature increased by the solar heat and collect heat.

In early spring, late autumn, and at night, it cools considerably, but during the day, the weather is so good that the temperature rises too much, and the vinyl sheet covering the greenhouse must be opened to ventilate the greenhouse. By utilizing the fact that the temperature of the circulating heat medium is sufficiently lower than the temperature of 1, heat absorption can be caused at the surface exposed portion of the heat exchange pipe. According to this, in addition to collecting heat, excessive temperature rise in the greenhouse can be suppressed. In particular, in the underground buried portion of the heat exchange pipe, it is possible to cool from the ground, and it is possible to prevent the ground temperature from rising excessively.

In this way, the heat exchange pipe that introduces heat from the heat storage tank and dissipates heat into the greenhouse is once buried in the ground and again exposed on the ground surface in the greenhouse. Can dissipate and collect heat.

Next, since a medium heating means for heating the heat medium to a predetermined temperature is provided in the middle of the heat radiation path returning from the surface-exposed side of the heat exchange pipe to the heat storage tank, for example, the weather is bad and the amount of solar radiation is considerably reduced. On the day when the heat collector or the heat exchange pipe hardly collects the heat of the solar heat, the heat medium below the set temperature can be heated to a predetermined temperature and returned to the heat storage tank. Therefore, at night, the heat exchange pipe can stably introduce a sufficiently heated heat medium having a predetermined temperature from the heat storage tank.

<Example> Next, an example of the present invention will be described below with reference to the drawings. FIG. 1 is an overall perspective view of a greenhouse heating system according to the present invention.

In FIG. 1, the greenhouse heating system includes a heat collector (1) for collecting solar heat, a heat storage tank (2) for storing the solar heat collected by the heat collector (1), and a heat storage tank (2). A heat exchange pipe (4) for radiating the introduced heat in the vinyl tunnel (T) and a medium heating means (5) for heating the heat medium to a predetermined temperature are provided.

The heat collector (1) has a plurality of stages of heat collecting tubes (1a) that are bent and formed into a substantially S-shape on the surface facing the sun, and the heat collecting tube (1a) is used for collecting heat such as water. It is provided so that the medium can be circulated. Then, the heat collector (1) is formed so that it can stand up so that the heat medium inside the tube allows the heat medium inside the tube to absorb the sun's rays, which is poured onto this opposing surface, but can efficiently collect the solar heat. There is.

Further, the heat collector (1) is equipped with a temperature sensor (10). The temperature sensor (10) detects an increase in temperature of the heat collector (1) and controls execution of a heat collecting step described later, and is electrically connected to the control panel (3).

In this embodiment, two heat collectors (1) are installed side by side, but the number of installed heat collectors (1) and the capacity are appropriately changed depending on the setting of the internal volume of the greenhouse and the heating temperature. It However,
The temperature sensor (10) only needs to be provided at one place even when a plurality of heat collectors (1) are installed.

A heat storage tank (2) is connected to the heat collector (1). The heat storage tank (2) comprises a tank body (25) for storing a heat medium and its storage body (26), and the heat medium is collected in the tank body (25) by the heat collector (1) and the heat exchange pipe (4). ) Side is provided with a submersible pump (20).

The submersible pump (20) is equipped with a discharge pipe (21) protruding above the lid (26). A two-way cocked joint (22) is attached to the upper end of the discharge pipe (21).
The one side cock (22a) of the joint (22) is connected to the control valve (2
3) is connected to the heat collector (1) side, and the other side cock (22b) is connected to the heat exchange pipe (4) side. In this case, one side cost (22a) and the other side cock (2
2b) can be switched so that the discharge pipe (21) can be either the heat collector (1) side or the heat exchange pipe (4) side or a common heat medium introduction path. It is provided.

A return pipe (11) for returning the heat medium is provided on the path from the heat collector (1) to the heat storage tank (2), and the end of the return pipe (11) is a lid (26). The heat storage tank (2) is closed and is opened above. Here, heat storage tank (2) →
Discharge pipe (21) → One-sided cock (22a) → Control valve (2
3) → Heat collector (1) → Return pipe (11) → Heat storage tank (2)
Thus, the heat medium circulation path on the heat collecting side in which the heat medium circulates sequentially is formed.

The submersible pump (20) is connected to the control panel (3) by wiring, and the temperature sensor (10) and the temperature sensor (4) described later are connected.
0) and the control panel (3).

The heat exchange pipe (4) is pulled into the vinyl tunnel (T), and once buried in the ridge (U), the underground buried portion (4a) and the ridge in the vinyl tunnel (T) again. (U) It is composed of the surface-exposed portion (4b) exposed on the upper surface, and is laid along the vicinity of the cultivated crop (P) (see FIG. 2). In consideration of heat collection efficiency, the heat exchange pipe (4) is provided in one in the underground buried portion (4a) and is branched into two in the surface exposed portion (4b). (See Figure 3).

This is, for example, on cold days and on days with low solar radiation,
Operate the joint (22) with the two-way cock to
If a) (22b) is opened and the heat medium is circulated not only on the collector (1) side but also on the heat exchange pipe (4) side,
Also in the surface exposed part (4b) of the heat exchange pipe (4),
The solar heat can be collected, and the surface exposed portion (4b), which is the heat radiation portion, can also function as an efficient heat collector.

In early spring, late autumn, and at night, it cools considerably, but during the day, the weather is so good that the temperature rises too much, and the vinyl sheet covering the greenhouse must be opened to ventilate the greenhouse. Utilizing the fact that the temperature of the circulating heat medium is sufficiently lower than the temperature of the heat exchange pipe (4) so that the heat in the vinyl tunnel (T) can be absorbed at the surface exposed portion (4b) of the heat exchange pipe (4). It was done. According to this, in addition to collecting heat, excessive temperature rise in the greenhouse can be suppressed. In particular, the ridge (U) can be cooled from the ground in the underground buried portion (4a), and the ground temperature can be prevented from rising excessively.

The ridge (U) in the vinyl tunnel (T) is also equipped with a temperature sensor (40). The temperature sensor (40)
The temperature rise of the ridge (U) due to solar heat is detected to control execution of a heat collecting step described later, and is electrically connected to the control panel (3).

A medium heating means (5) is provided in a path from the surface exposed portion (4b) of the heat exchange pipe (4) to the heat storage tank (2). The medium heating means (5) includes a boiler (5a) in which auxiliary tanks (5b) are arranged in parallel. In the medium heating means (5), the surface exposed portion (4b) of the heat exchange pipe (4)
The heat medium sent from is temporarily stored in the auxiliary tank (5b), heated there, and returned to the heat storage tank (2). Here, heat storage tank (2) → discharge pipe (21) → other side cock (22b) → heat exchange pipe (4)
(Underground part (4a) → surface exposed part (4b)) → medium heating means (5) → heat storage tank (2) Become.

In addition, the float switch (5
c) is installed. Float switch (5c)
Is electrically connected to the control panel (3) like the above-mentioned sensors, etc., detects when the heat medium in the auxiliary tank (5b) is low, and outputs the detected signal. It is sent to the control panel (3) to stop the heating system.

The boiler (5a) is turned on by a predetermined switch when the temperature of the heat medium in the auxiliary tank (5b) becomes equal to or lower than a set temperature. When the temperature sensor (40) detects that the temperature of the ridge (U) is below the set temperature, the operation is started, and the boiler (5a)
The submersible pump (20) described above is provided so as to take out the heat medium heated by the auxiliary tank (5b) for circulation. The submersible pump (20) is also controlled by the control panel (3) in this function.

In addition, as shown in FIG. 2, the heating system of this greenhouse has a large vinyl house (H) that covers a plurality of rows of vinyl tunnels (T) covering the ridges (U) and the cultivated crops (P) together. ) Has been applied to.

Next, the steps and functions of the greenhouse heating system will be described.

In FIG. 1, first, when the weather is good and the sunlight rays in the daytime are sufficiently strong, a large amount of thermal energy is supplied from the sun to the heat collector (1). At the same time, a large amount of solar heat is also supplied to the vinyl tunnel (T).

In this case, the temperature inside the collector (1) is constant (eg 35
(° C) or higher, the temperature sensor (10) detects it and activates the submersible pump (20) controlled by the control panel (3),
The heat medium in the heat storage tank (2) is sent to the discharge pipe (21), and the heat collecting step is executed.

That is, both the heat collector (1) side cock (22a) and the heat exchange pipe (4) side cock (22b) of the two-way cock joint (22) are opened. As a result, as shown in FIG. 3, the heat medium circulates between the heat storage tank (2) and the heat collector (1), and at the same time, between the heat storage tank (2) and the heat exchange pipe (4). It can circulate.

Thus, the solar heat poured into the heat collector (1) is collected by the heat medium, and the collected heat energy is stored in the heat storage tank (2). Further, the heat energy from the sun supplied into the vinyl tunnel (T) is collected by the heat medium passing through the heat exchange pipe (4), particularly the surface portion (4b), and stored in the heat storage tank (2). .

Further, the underground buried portion (4a) of the heat exchange pipe (4) can also absorb the ground temperature raised by the solar heat and collect heat. According to this, for example, in the autumn or spring when the sunlight in the daytime is sufficiently strong, the heat can be collected not only by the heat collector (1) but also by the heat exchange pipe (4), so that the greenhouse temperature at night is high. Has been found to increase by about 2-3 ° C.

Next, in early spring and late fall, it cools considerably at night,
On a day when the weather is too good and the temperature rises too much and the vinyl sheet covering the greenhouse must be opened to perform ventilation cooling, the heating system operated as described above should By utilizing the fact that the temperature of the circulating heat medium is sufficiently low, the heat in the vinyl tunnel (T) can be absorbed by the surface exposed portion (4b) of the heat exchange pipe (4). Thereby, in addition to heat collection, excessive temperature rise in the greenhouse can be suppressed. Particularly, in the underground buried portion (4a) in the ground, the ridge (U) can be cooled from the ground, and the ground temperature can be prevented from rising excessively.

In this way, the heat exchange pipe (4) that introduces heat from the heat storage tank (2) and dissipates the heat into the vinyl tunnel (T) is once buried in the ground, and is again stored in the vinyl tunnel (T).
Since it is exposed on the ground surface inside, it is possible to radiate and collect heat from both sides of the ground surface and the ground.

Next, at night when there is no sunlight, the control valve (2
With the 3) closed, operate the submersible pump (20) and execute only the heat dissipation step.

That is, the heat medium that has sufficiently accumulated heat in the daytime heat collection step and has reached a high temperature circulates only in the path on the heat exchange pipe (4) side to radiate heat in the vinyl tunnel (T), thereby cultivating in a greenhouse. The crop (P) is kept warm to prevent nighttime low temperature disasters. Regarding the operation of the submersible pump (20), a timer (not shown) provided in the operation panel (3)
It is preferable to perform it intermittently. According to this, the heat energy stored in the heat medium can be effectively used, and the cultivated crop (P) can be maintained at an appropriate growth temperature for a long time.

By the way, in bad weather such as rain, the sun's rays are extremely weak, and even in the heat collector (1), the heat exchange pipe (4)
However, the required heat energy is not sufficiently absorbed. In this case, circulation of the heat medium on the heat collector (1) side is unnecessary, and the control valve (23) is closed.

On the other hand, for this reason, if the temperature of the heat medium in the auxiliary tank (5b) is below the set temperature (for example, 30 ° C) (however, 50 ° C upper limit setting), the predetermined switch is turned on to operate the boiler (5a). To start. And temperature sensor (40)
The temperature of the ridge (U) is detected by the detection of
Submersible pump (2
0) is operated to take out the heat medium heated by the boiler (5a) from the auxiliary tank (5b). Then, the heat medium heated to the required temperature is returned into the heat storage tank (2).

As a result, the heat medium having a high temperature circulates only in the path on the heat exchange pipe (4) side, and the vinyl tunnel (T)
Heat can be dissipated inside to keep the cultivated crops (P) in the greenhouse warm and prevent low temperature disasters on bad weather. In addition, the boiler (5a) is not only for auxiliary use on bad weather like the above, but also for full-scale use on cold winter days and on days when the geothermal heat does not rise. Needless to say, it is useful.

In the heat collection step of the heating system described above, the distribution of the heat medium to be circulated between the heat collector (1) side and the heat exchange pipe (4) side is the most efficient depending on the intensity of the sunlight rays in the daytime. Be prepared to collect heat. That is, the heat collector (1) is far superior to the heat exchange pipe (4) in terms of heat collection efficiency. However, when there is solar heat that exceeds the heat collection capacity of the heat collector (1), or in order to positively fulfill the cooling function in the vinyl tunnel (T), the circulation amount on the heat exchange pipe (4) side was increased. It's better. The distribution of the heat medium can be adjusted by the joint (22) with the two-way cock or the control valve (23) on the heat collector (1) side.

Also, submersible pump (20) and two-way cocked joint (22)
If the operation adjustment of the control valve (23) and the like are electrically controlled by the control panel (2) based on the detection information of the temperature sensor (10) and the like, more efficient heating can be performed. Furthermore, a temperature sensor is also installed on the side of the vinyl tunnel (T) that serves as a greenhouse, and the temperature sensor detects the temperature conditions of both the heat exchange pipe (4) and the heat collector (1) at the same time, and Controlling the circulation of the medium results in a more preferable implementation.

In the heat collection step in the daytime, it is not necessary to constantly circulate the heat medium to the heat exchange pipe (4) side, and the heat exchange pipe (4) and the heat collector (1) are connected only when the sunlight is strong. Both media are circulated to increase the amount of heat collection, and if the sunlight becomes weak, stop the circulation on the heat exchange pipe (4) side,
The heat may be collected only by the efficient collector (1).

INDUSTRIAL APPLICABILITY The greenhouse heating system according to the present invention can be applied not only to the temperature of ridge cultivation but also to cultivation of various fruit trees, greenhouse water tanks for fish farming, heating of poultry farms, and the like.

Further, in this greenhouse heating system, since cold well water can be used as the heat medium, the heat exchange pipe (4) can be cooled in the summer and the like, and the ground temperature that has risen too much can be lowered. Can be used as a cooling pipe. According to this, the high temperature disaster of greenhouse cultivation crops in the summer can be prevented.

FIG. 4 shows a modified example of the heating system of the greenhouse. In this heating system, compared with the heating system shown in FIG.
The difference is that the joint (22) with a two-way cock and the control valve (23) provided on the heat collector (1) side are omitted. Therefore, in this heating system, a heat medium circulation system between the heat collector (1) and the heat storage tank (2), and a heat medium circulation system between the heat storage tank (2) and the heat exchange pipe (4). Are completely divided, and there is an advantage that the circulation route of the heat medium in the heating system can be simplified.

<Effects> As described above, according to the heating system of the present invention, the heat exchange pipe that introduces heat by the heat storage tank to radiate heat into the greenhouse is temporarily buried in the ground, and is again buried on the ground surface in the greenhouse. Since it is exposed to the outside, it is possible to radiate heat from both sides of the surface and the ground, and as a result, there is an effect that the heat emission efficiency is significantly increased.

Further, when the heat exchange pipe is not used for heat radiation in high temperature weather, it can be converted and used as an efficient heat collector in a greenhouse, so that the heat collection efficiency is improved and the economy is improved. be able to. Also in this case, since the heat exchange pipe can collect heat from both sides of the surface of the earth and the ground, there is an effect that the heat absorption efficiency is significantly increased.

Moreover, even in the same hot weather, even if the sunlight is too strong and the greenhouse temperature rises excessively, if the temperature of the circulating heat medium is sufficiently lower than the temperature inside the greenhouse, the heat exchange pipe Can cause heat absorption. Particularly, in the configuration of the present invention, since the heat medium flows through the heat storage tank from the embedded portion through the exposed portion, in the heat collecting process, the heat medium radiates heat from the exposed portion whose temperature rises first. Instead, it immediately flows through the heat storage tank to collect heat efficiently. Therefore, in addition to collecting heat, excessive temperature rise in the greenhouse can be suppressed. Particularly, in the underground buried portion, it is possible to prevent the ground temperature from rising excessively, and it is possible to cool from the inside of the ridge. Therefore, in early spring or late autumn when the temperature difference between daytime and nighttime is great, it exerts an extremely great effect on the adjustment of the atmospheric temperature in the greenhouse, and it is possible to maintain a very suitable environment for the growth of crops and the like.

In addition, even if the solar heat can hardly be collected in the heat collector and the temperature of the greenhouse does not rise, the heat medium below the set temperature can be heated to the predetermined temperature and returned to the heat storage tank, so heat exchange A sufficiently heated heat medium having a predetermined temperature can be stably supplied to the pipe. Moreover, since the auxiliary tank of the medium heating means is connected between the exposed portion of the heat exchange pipe and the heat storage tank, it not only assists the heating of the heat medium in the heat dissipation process, but also in the heat collection process described above. It is also possible to cool the heat medium collected at the exposed portion by the auxiliary tank. As described above, according to the present invention, it is possible to exhibit a peculiar effect that it is possible to perform greenhouse heating under a constant high temperature without being influenced by weather conditions.

[Brief description of drawings]

FIG. 1 is an overall perspective view of a heating system for a greenhouse showing an embodiment of the present invention, FIG. 2 is a sectional view of the greenhouse, FIG. 3 is a block diagram of a heat collecting step, and FIG. 4 is another heat collecting step. It is a block diagram of. (1) …… Heat collector, (2) …… Heat storage tank (3) …… Control panel, (4) …… Heat exchange pipe (4a) …… Underground buried part, (4b) …… Surface display Part (5) …… Medium heating means, (U) …… Ridge

Claims (3)

[Claims] 1. A heat collecting path for circulating a heat medium between a heat collector and a heat storage tank to store the solar heat collected by the heat collector in the storage tank, and releasing the heat stored in the heat storage tank into the greenhouse. In a heating system having a heat dissipation path, the heating unit includes a buried portion that is drawn into the greenhouse and buried in the ground, and a exposed portion that continuously appears in the greenhouse from the buried portion. Medium heating that heats the heat medium to a predetermined temperature, including a heat exchange pipe that circulates from the buried portion to the heat storage tank through the exposed portion and an auxiliary tank that is connected between the exposed portion of the heat exchange pipe and the heat storage tank A heating system for a greenhouse, comprising: 2. The heat medium introduction path from the heat storage tank of the heat collector and the heat exchange pipe is configured to be switchable to either one of the heat collector side and the heat exchange pipe side, or a path common to both. The heating system for a greenhouse according to claim 1, which has a heating system. 3. The greenhouse heating system according to claim 1, wherein the medium heating means is a boiler.