JP2015002711A - Air conditioner for greenhouse - Google Patents

Abstract

PROBLEM TO BE SOLVED: To develop a novel air conditioner for a greenhouse, which avoids a situation where a heat absorber of a heat pump causes performance degradation or inactivation due to adhesion of frost in winter and is capable of efficiently air-conditioning inside the greenhouse without requiring the use of a boiler.SOLUTION: An air conditioner 1 for a greenhouse of the invention comprising a heat absorber 2 which uses air in a greenhouse R as heat source, a heat absorber 3 which uses outside air as haet source, and a heat storage device 4 in which heat storage material H is housed, is characterized by transferring a heat medium from the heat absorber 2 which uses air in the greenhouse R as heat source to the heat storage device 4 to store in the heat storage material H the heat recovered in the greenhouse R in such a case that temperature in the greenhouse R rises in the daytime and a user wants to cool or dehumidify inside the greenhouse R, as well as by transferring a heat medium from the heat absorber 3 which uses outside air as heat source to the heat storage device 4 also to store in the heat storage material H the heat recovered from outside air in the heat absorber 3.

Description

  The present invention relates to an air conditioner that adjusts temperature and humidity in a greenhouse.

For example, in the cultivation of vegetables and fruits, a greenhouse in which the walls and ceiling of the building are covered with a light-transmitting material such as vinyl or glass is used in order to protect plants from the low temperature atmosphere in winter and at night. Many.
And in such a greenhouse, there existed what was conventionally performed using the heat pump for heating, cooling, and dehumidification of a room (for example, refer to patent documents 1).
However, when air conditioning in a greenhouse is performed using a heat pump, frost may adhere to the heat pump heat sink in winter (especially in the severe cold season), resulting in poor performance and inability to operate. For this reason, in such a greenhouse, there are many greenhouse facilities that are equipped with a boiler and perform heating in winter, and both initial costs and running costs are wasted.
In addition, heating by a boiler has a low carbon dioxide emission and is questioned from an environmental point of view, and other methods have been demanded.

JP-A-5-336847

  The present invention has been made in view of such a background, and avoids a situation in which performance deterioration or inability to operate due to frost on the heat sink of the heat pump in winter, and it is also necessary to use a boiler. It is an attempt to develop a new air conditioner that can efficiently air-condition the greenhouse.

First, the greenhouse air conditioner according to claim 1 is:
A heat absorber that uses air in the greenhouse as a heat source;
A heat absorber that uses outside air as a heat source;
A heat storage device containing a heat storage material, and a device for air conditioning a greenhouse with a heat pump,
This device transfers the heat medium from a heat absorber that uses air in the greenhouse as a heat source to the heat storage device when the temperature in the greenhouse rises during the daytime, and the heat collected in the greenhouse is collected. Is stored in the heat storage material,
In addition, the heat storage device is configured such that the heat medium can be transferred also from a heat absorber using outside air as a heat source, and heat collected from the outside air in the heat absorber is also stored in the heat storage material. Is.

Further, the greenhouse air conditioner according to claim 2 has the requirements of claim 1,
The heat storage material in the heat storage device gradually changes from a solid to a liquid as the heat collected from the greenhouse or outside air is stored, and the heat storage device sufficiently stores heat until the heat storage material becomes liquid. After that, when the cooling and dehumidifying operation of the greenhouse is continued, the heat medium transferred from the heat absorber using the air in the greenhouse as a heat source to the heat storage device is changed to a heat absorber using the outside air as the heat source. This is characterized in that the heat sink is switched to a heat radiator and cooling and dehumidification of the greenhouse are continuously performed.

Further, the greenhouse air conditioner according to claim 3 is in addition to the requirement according to claim 1 or 2,
When heating the inside of the greenhouse, the heating medium heated in the heat storage device is transferred to a heat absorber using air in the greenhouse as a heat source, and the heat absorber functions as a heater.
In addition, the heater using the air in the greenhouse as a heat source is configured so that the heat medium heated by the heat absorber using the outside air as the heat source can also be transferred,
Heating in the greenhouse can be performed using heat extracted from a heat storage device and heat recovered from a heat absorber using outside air as a heat source.

Further, the greenhouse air conditioner according to claim 4 has the requirements of claim 1, 2, or 3,
The greenhouse air conditioner is provided with a path for contacting the heat medium heated in the heat storage device with a heat absorber using outside air as a heat source, and when the frost adheres to the heat absorber in a severe cold season or the like and the heat absorption function is lowered. The fan of the heat absorber is stopped, the heat medium heated in the heat storage device is brought into contact, and the heat absorber is defrosted.

Further, the greenhouse air conditioner according to claim 5 is in addition to the requirement according to claim 1, 2, 3 or 4,
Sodium sulfate is applied to the heat storage material in the heat storage device, and water and other additives are added, so that the heat storage material has an appropriate freezing point and melting point between about 10 ° C. and 32 ° C. It consists of

The above-described problems can be solved by using the configuration of the invention described in each of the claims.
According to the first aspect of the present invention, the heat recovered from the greenhouse in which the daytime temperature rises and the heat recovered from the outside air having a relatively high temperature can be combined and stored in the heat storage material of the heat storage device. Even when the heat recovered from the inside is insufficient, the heat can be efficiently recovered from the outside air and stored (supplemented) in the heat storage device.
The temperature of the greenhouse may be adjusted by opening skylights and side windows for the purpose of preventing excessive temperature rise in the daytime even in winter. In the present invention, cooling and dehumidification of the greenhouse are efficient. Therefore, such an opening operation (because it closes at night and becomes an opening / closing operation) is unnecessary or can be minimized.

  According to the second aspect of the present invention, when heat is sufficiently stored until the heat storage material becomes liquid, the heat medium transferred from the heat absorber using air in the greenhouse as the heat source to the heat storage device is used as the heat source. In order to continue the cooling and dehumidification of the greenhouse by switching the heat absorber to a heat radiator (stopping the transfer to the heat storage device) And dehumidification) can be performed efficiently thereafter.

According to the invention described in claim 3, since the heat recovered from the outside air and the heat recovered from the heat storage device (heat storage material) can be used for heating the greenhouse, the severe cold season in which the heating capacity of the greenhouse air conditioner decreases. Etc., sufficient greenhouse heating is possible. In addition, in order to extract heat from the heat storage material and warm the inside of the greenhouse, in addition to using an evaporator (heater) of a heat pump as described above, a water circulation coil, a heat pipe, etc. are provided in the greenhouse to store heat. It is possible to transfer the heat medium heated by the apparatus (water in the water circulation coil) and heat the greenhouse.
Moreover, when heating a greenhouse using a heat pump apparatus, when there is a margin in the capability of the heat pump apparatus, the heat for the margin can be stored in a heat storage material (heat storage apparatus). Note that heat is stored in the heat storage material during an efficient time of the heat pump device (usually daytime).

  According to the invention of claim 4, for example, in the severe cold season, when frost adheres to the heat absorber using the outside air as a heat source and the capacity of the heat absorber decreases, the heat absorber is used by using the heat of the heat storage device. Therefore, it is possible to restore the capacity of the heat sink and efficiently heat the greenhouse.

  According to the invention of claim 5, since sodium sulfate is used as the heat storage material and the freezing point (melting point) can be adjusted between about 10 ° C. and 32 ° C. with water and other additives, the greenhouse air conditioner Temperature can be adjusted to the most efficient temperature, and the cooling, dehumidification and heating of the greenhouse can be performed efficiently.

It is a figure which shows the case where the inside of the greenhouse which temperature rises mainly during the day is cooled and dehumidified by applying the greenhouse air conditioner of the present invention, and transfers the heat medium from the heat absorber using the air in the greenhouse as a heat source to the heat storage device In addition, while storing the heat recovered in the greenhouse in the heat storage material, the heat medium is also transferred to the heat storage device from the heat absorber using the outside air as the heat source, so that the heat recovered from the outside air can also be stored in the heat storage material It is explanatory drawing which shows. It is a figure showing the case where cooling and dehumidification in the greenhouse are continuously performed after the heat storage material changes from solid to liquid in association with storing heat recovered from the inside of the greenhouse and outside air in the heat storage device. Transfer (switch) the heat medium that has been transferred from the heat absorber that uses air as the heat source to the heat storage device to the heat absorber that uses outside air as the heat source, and use the heat absorber as a radiator to cool and dehumidify the greenhouse. It is explanatory drawing which shows a mode made to perform continuously. When heating the inside of a greenhouse, the heat medium heated in the heat storage device is transferred to a heat absorber using air in the greenhouse as a heat source, and the outside air is heated while using the heat absorber as a heater to heat the greenhouse. The heat medium heated by the heat absorber using the heat source is transferred to the heat absorber using the air in the greenhouse as the heat source, and the heat extracted from the heat storage device and the heat recovered from the heat absorber using the outside air as the heat source are It is explanatory drawing which shows a mode that it utilized for the heating of a greenhouse. When using a water circulation coil or heat pipe heat exchanger as a heater that heats the greenhouse using the heat stored in the heat storage device, frost adhering to the heat sink using the outside air as a heat source in the severe cold season, etc. It is explanatory drawing which shows collectively the case where the defrost path | route to remove is provided. FIG. 2 is an explanatory diagram showing a state in which a heat absorber (evaporator) using outside air as a heat source is provided in addition to FIG. 1 so that heat can be efficiently stored in the heat storage device.

  The mode for carrying out the present invention includes one described in the following embodiments, and further includes various methods that can be improved within the technical idea.

The greenhouse air conditioner 1 of the present invention efficiently performs air conditioning (so-called cooling, dehumidification, heating, etc.) in the greenhouse R. As shown in FIG. 1, as an example, air in the greenhouse R is used as a heat source. It is comprised by the heat pump structure provided with the heat absorber 2 which uses the external air as a heat source, and the heat storage apparatus 4 which accommodated the heat storage material H.
In addition, the greenhouse air conditioner 1 allows various routes to function depending on the air conditioning status (operation method) in the greenhouse R. For example, FIG. 1 shows the operation status when the greenhouse R is cooled or dehumidified. A path for storing the heat recovered in the greenhouse R in the heat storage material H of the heat storage device 4 (this is the heat storage material heat storage greenhouse cooling path L1) and a path for storing the heat recovered from the outside air in the same heat storage material H (This is the heat storage material heat storage outside air heat absorption path L2).

Moreover, FIG. 2 has shown the driving | running state in the case of continuing the cooling in the greenhouse R, or a dehumidification operation, after fully storing in the thermal storage material H of the thermal storage apparatus 4 by said cooling / dehumidification operation. The heat absorber 3 using the outside air as a heat source is switched to a heat radiator (same as “3”), and here, the heat recovered in the greenhouse R is released. Here, such a path is referred to as an outside air radiation greenhouse cooling path L3 in this specification.
Further, FIG. 3 shows an operation situation when the inside of the greenhouse R is heated. In this case, the heat absorber 2 using the air in the greenhouse R as a heat source is switched to a heater (hereinafter, the same reference numeral “ 2 ”), where the heat stored in the heat storage device 4 is released and the inside of the greenhouse R is heated (this is referred to as a heat storage material radiating greenhouse heating path L4), and the heat recovered from the outside air is A path for heating the inside of the greenhouse R by discharging with the heater 2 (this is referred to as an outside air endothermic greenhouse heating path L5) is functioning.
Hereinafter, the greenhouse air conditioner 1 of the present invention will be substantially described while explaining each of these paths.

First, the heat storage material heat storage greenhouse cooling path L1 and the heat storage material heat storage outside air heat absorption path L2 of FIG. 1 will be described. These routes are operated when the temperature in the greenhouse R rises excessively in the daytime and it is desired to cool or dehumidify the greenhouse R.
Among these, the heat storage material heat storage greenhouse cooling path L1 transfers the heat medium from the heat absorber 2 using the air in the greenhouse R as a heat source to the heat storage device 4 as described above, and the heat collected in the greenhouse R is transferred to the heat storage material H. It is a path to store. For this reason, the main structural members of the heat storage material heat storage greenhouse cooling path L1 are the heat absorber 2, the heat storage device 4, and the compressor 5 that use air in the greenhouse R as a heat source.

On the other hand, the heat storage material heat storage outside air heat absorption path L <b> 2 is a path for transferring a heat medium from the heat absorber 3 using the outside air as a heat source to the heat storage device 4 and storing heat collected from the outside air in the heat storage material H in the heat absorber 3. In this embodiment, the heat storage material heat storage outside air heat absorption path L2 is provided (combined) with the heat storage material heat storage greenhouse cooling path L1. Specifically, as shown in FIG. 1, the front and rear portions for transferring the heat medium to the heat storage device 4 in both paths are formed as a common circuit, and the heat storage devices from both the heat absorbers 2 and 3 are formed in this common portion. 4 is provided with a compressor 5 for transferring the heat medium.
Thus, the greenhouse air conditioner 1 of the present invention can store heat collected from the inside of the greenhouse R and heat collected from the outside air together with the heat storage material H of the heat storage device 4. Thereby, even when the recovered heat from the greenhouse R is insufficient, the heat can be efficiently recovered from the outside air and stored (supplemented) in the heat storage device 4.
Incidentally, the main components of the heat storage material heat storage outside air heat absorption path L2 are the heat absorber 3, the heat storage device 4, and the compressor 5.

Next, the outside air radiation greenhouse cooling path L3 in FIG. 2 will be described. Prior to this, the heat storage material H in the heat storage device 4 will be described. The heat storage material H is preferably one that gradually changes from solid to liquid with the progress of heat storage, that is, the heat collected from the inside and outside of the greenhouse R (effective for using latent heat). H becomes a liquid in a state where heat is sufficiently stored. Therefore, after the heat storage material H becomes liquid, when it is desired to continue cooling and dehumidifying operation of the greenhouse R, as shown in FIG. 2, the outside heat radiation greenhouse cooling path L3 is made to function. The heat medium transferred from the heat absorber 2 using the air in the greenhouse R as the heat source to the heat storage device 4 is transferred to the heat absorber 3 using the outside air as the heat source (that is, the transfer to the heat storage device 4 is stopped). The heat absorber 3 is switched to the heat radiator 3 to continuously cool and dehumidify the greenhouse R.
Here, in the present embodiment, the flow path of the heat medium is switched by the four-way valve 6.
In such an outside air radiation greenhouse cooling path L3, the heat medium flowing into and out of the radiator 3 using the outside air as a heat source is the cooling / dehumidifying operation (heat storage material heat storage outside air heat absorption path L2) shown in FIG. Is the opposite direction.
Incidentally, the main components of the outside air radiation greenhouse cooling path L3 are the heat absorber 2, the radiator 3, and the compressor 5 because the heat storage device 4 is not allowed to function substantially.

Moreover, as the heat storage material H in the heat storage device 4, sodium sulfate is applied as an example, and it is set to have an appropriate freezing point and melting point between about 10 ° C. and 32 ° C. by adding water and other additives. Is done. That is, the application of sodium sulfate as the heat storage material H is capable of adjusting the freezing point (melting point) of the heat storage material H to a temperature that is most efficient for the greenhouse air conditioner 1. Heating, cooling, and dehumidification can be performed efficiently.
In addition, sodium sulfate is a salt that is completely harmless to the human body and exists in nature. It is an incombustible material, so there is no fear of fire, etc., and it is extremely inexpensive and has excellent thermal conductivity. ing.
Incidentally, the use of paraffin as the heat storage material H is also conceivable, but paraffin has lower thermal conductivity than sodium sulfate, and there is a concern that the performance of the entire system may be reduced. In addition, paraffin is relatively troublesome for adjustment (mixing) for obtaining a desired freezing point (melting point), and sodium sulfate is more realistic.

Next, the heat storage material heat radiation greenhouse heating path L4 and the outside air endothermic greenhouse heating path L5 of FIG. 3 will be described. These routes are routes that warm the inside of the greenhouse R at night or in winter when the temperature decreases.
Among them, the heat storage material radiating greenhouse heating path L4 transfers the heat medium heated in the heat storage device 4 to the heat absorber 2 using air in the greenhouse R as a heat source, and the heat absorber 2 is used as a heater. This is a route for heating the inside of the greenhouse R with the heat recovered from the material H. For this reason, the main structural members of the heat storage material heat radiation greenhouse heating path L4 are the heat absorber 2, the heat storage device 4, and the compressor 5.

On the other hand, the outside air endothermic greenhouse heating path L5 transfers the heat medium from the heat absorber 3 that uses outside air as a heat source to the heater 2 that uses air inside the greenhouse R as a heat source, and heat inside the greenhouse R is recovered from the outside air. It is a route to heat.
In this embodiment, the outdoor air endothermic greenhouse heating path L5 is provided (combined) with the heat storage material heat dissipation greenhouse heating path L4.
Specifically, as shown in FIG. 3, the heat absorber 3 (external air is used as a heat source) in the course of transferring a heat medium from the heat storage device 4 to the heater 2 (heater 2 using air in the greenhouse R as a heat source). The heat medium heated by the heat absorber 3) is joined and transferred to the heater 2, and from the heater 2 (heater 2 using air in the greenhouse R as a heat source) to the heat storage device 4 The heat medium after heating the inside of the greenhouse R is divided into the heat absorber 3 (the heat absorber 3 using the outside air as a heat source) from the middle of the path for transferring the heat medium.
Incidentally, the main components of the outdoor air endothermic greenhouse heating path L5 are the heater 2, the heat absorber 3, and the compressor 5.

In addition, in taking out heat from the heat storage device 4 and heating the inside of the greenhouse R, not only the heater 2 (heat pump evaporator) of the heat storage material heat radiation greenhouse heating path L4, but also, for example, as shown in FIG. A water circulation coil 7 and a heat pipe heat exchanger 8 are provided in the greenhouse R, and a heat medium (water in the case of the water circulation coil 7) heated by the heat storage material H (heat storage device 4) is transferred to the greenhouse R from the heat storage material H. It is possible to heat the inside of the greenhouse R with the recovered heat. Of course, all of these can be used together, or can be appropriately selected and applied.
Here, the symbol “7P” in the figure is a symbol attached to the water circulation pump. Further, when the heat medium is transferred to the heat pipe heat exchanger 8, it is possible to transfer (circulate) the heat medium by so-called natural circulation.

In addition, frost adheres to the heat sink 3 that uses outside air as a heat source in severe cold seasons, etc., and it is considered that the heat absorption function is lowered and the entire apparatus is shut down. Therefore, the greenhouse air conditioner 1 includes a defrost path of the heat absorber 3. It is preferable to include an LD. Therefore, for example, as shown in FIG. 4, the heat medium heated by the heat storage device 4 can be formed so as to come into contact with the heat absorber 3 using outside air as a heat source. This is a defrost route indicated by “LD”. Specifically, a mode in which the heat medium heated by the heat storage material H is defrosted by showering on the heat absorber 3 is exemplified. Here, reference numeral “9” in the figure denotes a defrost pump.
Note that the heat medium in the defrost path LD and the heat medium flowing through the heat pipe heat exchanger 8 may be different from the heat medium in the paths L1 to L5 for cooling, dehumidifying and heating the greenhouse R. It does not matter, and the same type may be used.

  Further, FIG. 1 shows a heat absorber 3 that cools and dehumidifies the inside of the greenhouse R and stores the collected heat in the heat storage device 4 (heat storage material H) while using outside air as a heat source if necessary. In order to efficiently recover heat from both sides. However, for example, as shown in FIG. 5, it is possible to further provide a heat absorber 10 that uses outside air as a heat source to recover heat from the outside air more efficiently.

In addition, when applying the greenhouse air conditioner 1 (heat pump device) of the present invention, it was judged that the temperature in the corresponding area where the greenhouse R was installed would be cooled at night due to weather forecasts and meteorological conditions, and the temperature would not rise so much in the daytime. In this case, since it is considered that there is a limit (low) in the heat recovery from the greenhouse R in the daytime, for example, the heat absorber 3 using the outside air as a heat source from the daytime is fully operated or a new heat absorber 10 is also used. For example, a mode in which heat is stored in the heat storage device 4 sufficiently can be employed.
In this way, the heat pump device is made to exhibit the maximum efficiency in accordance with the weather conditions and usage conditions of the day, and the optimum heat input / output of the heat storage device 4 is performed using IT (Information Technology). be able to. In addition, in order to operate a farm having a large number of such heat pump devices (greenhouses) with optimum efficiency, it is possible to connect them with a communication facility and perform centralized management efficiently.

1 Greenhouse air conditioner 2 Heat absorber (heater) using air in the greenhouse as a heat source
3 Heat absorber (heat radiator) using outside air as heat source
4 Heat storage device 5 Compressor 6 Four-way valve 7 Water circulation coil 7P Water circulation pump 8 Heat pipe heat exchanger 9 Defrost pump 10 Heat absorber

H Thermal storage material R Greenhouse

L1 heat storage material heat storage greenhouse cooling path L2 heat storage material heat storage outdoor air heat absorption path L3 outdoor air heat dissipation greenhouse cooling path L4 heat storage material heat dissipation greenhouse heating path L5 outdoor air heat absorption greenhouse heating path LD defrost path

Claims (5)

A heat absorber that uses air in the greenhouse as a heat source;
A heat absorber that uses outside air as a heat source;
A heat storage device containing a heat storage material, and a device for air conditioning a greenhouse with a heat pump,
This device transfers the heat medium from a heat absorber that uses air in the greenhouse as a heat source to the heat storage device when the temperature in the greenhouse rises during the daytime, and the heat collected in the greenhouse is collected. Is stored in the heat storage material,
Further, the heat storage device is configured so that the heat medium can be transferred also from a heat absorber using outside air as a heat source, and heat collected from the outside air in the heat absorber is also stored in the heat storage material. Greenhouse air conditioner.
The heat storage material in the heat storage device gradually changes from a solid to a liquid as the heat collected from the greenhouse or outside air is stored, and the heat storage device sufficiently stores heat until the heat storage material becomes liquid. After that, when the cooling and dehumidifying operation of the greenhouse is continued, the heat medium transferred from the heat absorber using the air in the greenhouse as a heat source to the heat storage device is changed to a heat absorber using the outside air as the heat source. 2. The greenhouse air conditioner according to claim 1, wherein the heat sink is switched to a radiator to continuously cool and dehumidify the greenhouse.
When heating the inside of the greenhouse, the heating medium heated in the heat storage device is transferred to a heat absorber using air in the greenhouse as a heat source, and the heat absorber functions as a heater.
In addition, the heater using the air in the greenhouse as a heat source is configured so that the heat medium heated by the heat absorber using the outside air as the heat source can also be transferred,
The greenhouse air conditioning according to claim 1 or 2, wherein heating in the greenhouse can be performed using heat extracted from a heat storage device and heat recovered from a heat absorber using outside air as a heat source. apparatus.
The greenhouse air conditioner is provided with a path for contacting the heat medium heated in the heat storage device with a heat absorber using outside air as a heat source, and when the frost adheres to the heat absorber in a severe cold season or the like and the heat absorption function is lowered. The greenhouse air conditioner according to claim 1, 2 or 3, wherein the fan of the heat absorber is stopped, the heat medium heated in the heat storage device is brought into contact with the heat absorber, and the defrost of the heat absorber is performed. .
  Sodium sulfate is applied to the heat storage material in the heat storage device, and water and other additives are added, so that the heat storage material has an appropriate freezing point and melting point between about 10 ° C. and 32 ° C. The greenhouse air conditioner according to claim 1, 2, 3 or 4.

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