JPS58134918A - Heating and cooling system in horticulture greenhouse - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Technical Field of the Invention The present invention relates to a heating and cooling system for a greenhouse for greenhouse horticulture, and particularly to a heating and cooling system that uses groundwater as a heat source.

(2) Background of the technology In greenhouse horticulture, greenhouse horticulture not only utilizes the solar heat energy collected by the greenhouse, but also actively manages temperature in accordance with the ecology of the crops. In other words, it is necessary to prevent excessive cooling at night in winter in order to promote translocation and maintain crop growth. For this purpose, for example, it is necessary to operate a heater or collect solar heat energy during the night using a solar system. Heat is stored and released during the night to warm the body. In addition, it is necessary to create a relatively low-temperature atmosphere at night during the summer to prevent coloring or growth of seedlings and fruits. For this purpose, for example, underground water is pumped up and sprinkled on the roof of the greenhouse, or the greenhouse is cooled by replacing it with cold air using a heat exchanger.

However, the use of space heaters has become a problem as the price of oil, the main energy source, continues to rise, and heating using solar systems is affected by the weather, especially the hours of sunshine. There are regional regulations related to this. In addition, if groundwater is used in a simple manner, the amount of groundwater used is large, and a large heating and cooling effect cannot be expected.

Thus, there is a desire to develop a heating and cooling system for greenhouses that achieves energy savings and is highly efficient.

(3) Prior art and problems Conventionally, for example, a water-to-air counterflow type heat exchanger is installed in a greenhouse, and a heat storage water tank is installed and connected to the heat exchanger through piping. A system that exchanges the heat of the air and stores it as hot water in a heat storage water tank, and at night, this hot water is reversed through a heat exchanger and converted into hot air for radiant heating.
Alternatively, so-called geothermal heat exchange houses have been put into practical use, in which heat exchange air channels are buried underground, warm air is flowed through the air channels during the day, and heat is stored underground, and then released at night. There is. However, if there is no sunlight during the day, the function cannot be achieved, and especially in the latter case, a huge amount of air passages are required, which is approximately equal to the greenhouse floor area, which increases construction costs, and uses air as a medium. The disadvantage is that the thermal efficiency is low.

In addition, for example, a water-to-air counterflow type heat exchanger is installed in the greenhouse, and this exchanges heat between the groundwater of 16 to 17 (C) and the air in the greenhouse to lower the room temperature by 10% for nighttime heating in winter. ℃
In addition, in the case of summer cooling, heating and cooling systems that maintain the room temperature below 22-24 degrees Celsius have been attempted, but this method requires a small amount of groundwater and is therefore subject to location constraints. There's a problem.

(4) Purpose of the Invention In view of the problems of the prior art described above, the present invention provides a highly efficient greenhouse that does not use any fuel such as petroleum, does not require solar irradiation, and uses only a small amount of ground water. The purpose is to obtain a heating and cooling system.

(5) Structure of the Invention The present invention installs a high-performance water-to-air counterflow type heat exchanger that operates at a low temperature difference inside a greenhouse, and also connects and installs a unitized water storage tank outside the greenhouse. The heat exchanger and the water storage tank are connected with each other with piping, and a heat pump that operates using groundwater as a heat source is installed and connected with the water storage tank with piping, and during winter heating, the groundwater is used as a low heat source. Operate the heat pump, store hot water in a water tank, use the hot water to convert it into hot air through a heat exchanger to heat the greenhouse, and for summer cooling, operate the heat pump in the opposite direction using groundwater as the cooling heat source. To provide a heating and cooling system characterized in that cold water is stored in a water tank and the cold water is used to convert into cold air by a heat exchanger to cool the inside of a greenhouse.

(6) Examples of the invention Embodiments of the present invention will be described below based on the accompanying drawings.

FIG. 1 is a diagram showing the system of each device in the groundwater utilization system according to the present invention. In the figure, l is a heat exchanger 2a installed in the greenhouse 5.

2b is a water tank connected by piping 6, 3 is a water tank,
4 indicates a well, respectively. And heat exchanger 1 and water tank 2
m+2b are piped 10 m to each other via circulation sonde 7.
* Connected with 10 b, and water tank 2 a e 2 b
and the heat pump 3 are mutually connected to the piping 1 via the circulation I pump 8.
1a and llb, and further heat pump 3 and well 4
are connected to each other by pipes 12m and 12b via a circulation ponder 9. Here, a large number of heat exchange tubes (not shown) are arranged in the heat exchanger 1, and the air introduced from the air intake port 13 is circulated while passing through the gap between the heat exchange tubes. Heat is exchanged with water 19, and warm or cold air is air discharged through the air outlet 14.
is released into the greenhouse 5. At this time, air and water circulation 19
Since the water flows in countercurrents, the heat exchange efficiency is extremely high, and the temperature of the water discharged from the heat exchanger approaches the room temperature of the greenhouse, allowing effective heat exchange even with a low temperature difference. It has become. In addition, in the water storage tanks 2m and 2b, an upper water supply and drainage port 15m and a lower water supply and drainage port 15b are provided as shown in the figure.
m, so that cold water preferentially flows back through the lower water supply/drainage port 15b. This prevents mixed flows of the circulating water 19, and the water storage tanks 2m and 2b are successively filled with hot or cold water. Furthermore, the heat pump 3 has a cooler 16,
It is composed of a condenser 17 and a compressor 18, and when used for heating, that is, when underground water 20 is used as a low heat source, the cooler 16 and the well 4, and the condenser 17 and the water storage tanks 2m and 2b are connected. is,
On the other hand, when used for cooling, that is, when underground water 20 is used as a cooling heat source, the cooler 16 and water storage tank 2a
, 2b, each pipe 11 m long so that the condenser 17 and well 4 are connected.

11b, 12a, and 12b are switched.

The heat pump 3 used here is designed to have sufficient performance even with a small flow of heat source water (groundwater).

With this configuration, during winter heating, the heat pump 3 is operated first, and the circulation pumps 8 and 9 are operated at the same time.

As a result, the refrigerant in the compressor 3 absorbs the heat of the groundwater 20 in the cooler 16 and evaporates, and the refrigerant in the compressor 1
After being pressurized at step 8, the water moves to the condenser 17, where it releases heat to the circulating water 19, liquefies itself, and returns to the cooler 16 again. The circulating water 19 is heated by the action of the refrigerant, but at this time, the circulating water 19 is introduced into the flow indicated by the solid line H arrow in the figure, that is, into the upper water supply and drainage port 15 m of the water storage tank 2 m long. and water tank 2b
The hot water is discharged from the lower water supply/drainage port 15b, and the water tanks 2m and 2b are successively filled with warm water. After obtaining a predetermined amount of heat storage in this way, when the heat exchanger 1 is operated and the circulation pongua is operated at the same time, heat exchange occurs between the cold air introduced from the air intake port 13 and the circulating water 19. The heated air is discharged from the air outlet 14.
The greenhouse 5 is heated by the heat released from the gas.

The circulating water 19 flows as indicated by the dotted arrow H in the figure.)
, warm water is preferentially passed through a heat exchanger, cooled to near room temperature, and recirculated as cold water.

On the other hand, for summer cooling, the heat pump 3 can be operated in the opposite direction, that is, the groundwater 20 can be introduced into the condenser 17 and the circulating water 19 can be introduced into the cooler 16. This allows cold water to flow into the water storage tank 2a p2b. The cold water that is not stored is used to cool the greenhouse 5 by the heat exchanger 1. However, the flow of circulating water is determined by solid line arrow C and dotted line arrow C in the diagram.
a, 2b are sequentially filled with cold water, and heat exchanger 1
Cold water is preferentially flowed through the tank, heated to near room temperature, and then refluxed as hot water.

Therefore, in actual operation of the heating/cooling system described above, the heat exchanger 1 is operated only at night when heating and cooling is required (for example, from 8:00 pm to 6:00 the next morning), and the energy necessary for this is transferred to the heat pump 3 throughout the day. (24 hour) driving instructions are used. FIG. 2 is a basic diagram showing the heat dissipation capacity of the heat exchanger and heat pump to effectively realize such operating conditions. From this, the heat dissipation (cooling) capacity of the heat exchanger indicated by A, for example, 10 hours (hr)
If we set the capacity of the heat pump so that the value after integration and the value after 24 hours of heat dissipation (cooling) capacity of the heat pump shown by B are the same value Q, that is, the heat dissipation (cooling) capacity of the heat pump [ Heat radiation (cooling) capacity of heat exchanger XI
If set to 0/24), effective heat utilization will be measured with one cycle per day.

Specifically, the required capacity of the heat pump is set by using the theoretical calculation shown in FIG. 3 and the condenser outlet water temperature or heat exchanger inlet water temperature for 1 heat and 4 cycles as parameters. Figure 93 shows the heating performance in the case of radiation heating.
br ), the required heat dissipation capacity of the heat pump QB (keg
/hr), the amount of water from the heat source (groundwater) entering the cooler side of the heat pump v (z/mtn), the artificial water temperature of the circulating water condenser wTCc), and the set room temperature of the greenhouse heating ATCC)
The interrelationship between the heat exchanger inlet water temperature CC of the circulating water expressed as 3, 5, 40° 45° is shown as a meter. For example, the water temperature at the inlet of the heat exchanger for circulating water should be set to 40
(C) and the set room temperature is 16 CC), the heat dissipation capacity of the heat exchanger is approximately 20,500 (ke&t/hr).
), the heat dissipation capacity of the heat pump required to supply this energy is approximately 8.500 (kcal/hr). At this time, the condenser artificial water temperature of the heat pump is 23 (C), and the heat source water amount is 10.3 (C).
L/mf).

By the way, in the case of air conditioning, using the same calculation, for example, if the temperature of the circulating water heat exchanger is 7-5 CC)% and the set room temperature is 28 (t?:), the cooling capacity of the heat exchanger is approximately 1
7.500 (kcLt/hr), the cooling capacity of the heat pump required for this is approximately 7,300 (ke&t/hr)
becomes.

(7) Effects of the Invention As explained in detail above, the heating and cooling system of the present invention makes it possible to effectively heat and cool a greenhouse by using groundwater with a small flow rate, and can be used continuously for a long time. High-performance operation is achieved due to stable operation, and the overall equipment capacity can be reduced, such as by being able to downsize an expensive heat pump.

Furthermore, since it does not use any fuel such as petroleum, and does not require sunlight to enter like solar systems, it has great economic effects and has the advantage of not being restricted by location conditions. It is possible to set the temperature at a higher level (higher or lower temperature) than other systems.
Therefore, it has the effect of widening the range of use of cultivated crops.

[Brief explanation of the drawing]

FIG. 1 is a system diagram showing a heating and cooling system according to the present invention;
Figure 2 is a basic diagram showing the heat dissipation (cooling) capacity of a heat exchanger and heat pump, and Figure 3 is a diagram showing the required heat dissipation capacity of a heat pump. It is a parameter. 1... Heat exchanger, 2a, 2b... Water tank, 3...
Heat pump, 4... Well, 5... Greenhouse 16/10
a. 10 b, 11 ae 1 l b, 1-2 m
, 12 b ”・Piping, 7.8.9... Circulation pump, 13... Air intake port, 14... Air outlet port, 15
ae15b... Water supply and drainage port, 16... Cooler, 17
...Condenser, 1.8...Compressor, 1
9... Circulating water, 20... Groundwater. Patent Applicant Nepon Co., Ltd. Representative Patent Attorney Akihiro Kukimoto - Figure 2 10 12 14 16 18 20 ″t′ し・AT('C) Figure 3

Claims (1)

[Claims] (1) The heating and cooling system for the greenhouse uses groundwater, installing a water-to-air counterflow heat exchanger inside the greenhouse, installing a connected water tank and heat pump outside the greenhouse, and installing a well to take in groundwater. the heat exchanger and the water storage tank are connected to each other by piping via a circulation pump; the water storage tank and the heat exchanger are connected to each other by piping via the circulation pump; A heating and cooling system for a greenhouse for greenhouse horticulture, characterized in that the spaces are connected by piping via a pump. (The 2-inch heat pump is operated continuously for 24 hours,
On the other hand, the heat exchanger is operated during the required time period, and the amount of heat released from the heat exchanger is determined by using both the stored heat amount and the heat amount supplied by the heat pump. Heating and cooling systems in horticultural greenhouses.