JP2012078080A - Underground heat exchanger and heat pump utilizing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a refrigerant and a lubricant in a pipe from flowing into the soil even if a pipe connected to a refrigerant circuit is broken.SOLUTION: An underground heat exchange section (21) in which a heat medium is sealed, and a phase of the heat medium is changed by collecting heat from the soil in the ground is disposed in a tubular body pipe (22). A sub-heat exchange section (25) is connected to the underground heat exchange section (21) to introduce the heat medium thereto. The body pipe (22) is vertically buried in the ground. The sub-heat exchange section (25) is disposed in an outdoor unit (30) (heat source machine (30)) receiving a heat source-side heat exchanger (80). In the heat source-side heat exchanger (80), the heat exchange with the heat medium is performed by utilizing the phase change of the heat medium introduced to the sub-heat exchange section (25).

Description

  The present invention relates to an underground heat exchanger that collects heat from soil, and a heat pump using the underground heat exchanger.

  Some so-called heat pump heating systems that perform heating using a refrigeration cycle evaporate the refrigerant by using underground heat as a heat source. In such a heat pump heating system using geothermal heat, a geothermal heat exchanger that collects geothermal heat from the ground is used (see, for example, Patent Document 1). In the underground heat exchanger of Patent Document 1, a pipe (referred to as an embedded pipe in this specification) having a heat medium (secondary medium) inside is buried in the ground, and the heat medium in the buried pipe is buried in the ground. Evaporate with heat. Then, a pipe is branched from the buried pipe, a heat exchanger (referred to as a heat source side heat exchanger for convenience of explanation) is attached to the branch pipe, and heat recovered by the heat source side heat exchanger is used as a heat pump heating system. It is used as a heat source.

International Publication No. WO2004 / 111559 Pamphlet

  In the example of Patent Document 1, the heat source side heat exchanger is attached above the buried pipe, that is, facing the ground surface. Since the heat source side heat exchanger is connected to the refrigerant circuit of the heat pump heating system by piping, for example, when the piping is damaged due to secular change or the like, refrigerant or lubricating oil in the refrigerant circuit tube may flow into the soil .

  The present invention has been made paying attention to the above-mentioned problem, and aims to prevent refrigerant, lubricating oil, etc. in the pipe from flowing into the soil even if the pipe connected to the refrigerant circuit is damaged. Yes.

In order to solve the above-mentioned problem, the first invention
A heat pump having a refrigerant circuit (10) having a heat source side heat exchanger (80) and a use side heat exchanger (60) and performing a vapor compression refrigeration cycle,
A heat medium is enclosed inside the tubular body tube (22), and a ground heat exchanging section (21) that changes the phase of the heat medium by collecting heat from the soil in the ground,
A sub heat exchange section (25) connected to the underground heat exchange section (21) and introduced with the heat medium;
The main body pipe (22) is buried vertically in the ground,
The auxiliary heat exchanger (25) is provided in a heat source unit (30) that houses the heat source side heat exchanger (80),
The heat source side heat exchanger (80) performs heat exchange with the heat medium by utilizing a phase change of the heat medium introduced into the sub heat exchanger (25).

  In this configuration, the auxiliary heat exchange unit (25) is provided in the heat source unit (30). Therefore, even if the pipe (11) constituting the refrigerant circuit (10) is damaged, the refrigerant, lubricating oil, etc. in the pipe (11) remain in the heat source unit (30).

In addition, the second invention,
In the heat pump of the first invention,
The refrigerant circuit (10) is characterized in that the refrigerant circulates so that the heat source side heat exchanger (80) functions as an evaporator and the use side heat exchanger (60) functions as a condenser. To do.

  With this configuration, the heat pump can be operated using underground heat (for example, heating operation of an air conditioning system).

In addition, the third invention,
In the heat pump of the second invention,
A transport device (201) for transporting the heat medium evaporated in the underground heat exchange section (21) to the sub heat exchange section (25) is provided.

  In this configuration, since the gaseous heat medium in the main body pipe (22) is transported by the transport device (201), for example, the piping between the main body pipe (22) and the auxiliary heat exchange section (25) When the pressure loss is large, the heat medium can be circulated effectively.

In addition, the fourth invention is
In the heat pump of the second or third invention,
An air heat exchanger (401) connected to the refrigerant circuit (10) for exchanging heat with air;
The refrigerant circuit (10) includes a first operation mode in which the refrigerant circulates so that the air heat exchanger (401) functions as a condenser and the use side heat exchanger (60) functions as an evaporator. A second operation mode in which the refrigerant circulates so that the heat source side heat exchanger (80) functions as an evaporator and the use side heat exchanger (60) functions as a condenser; and the heat source side heat exchange Refrigerant switching to switch the third operation mode in which the refrigerant circulates so that the heat exchanger (80) and the air heat exchanger (401) function as an evaporator and the use side heat exchanger (60) functions as a condenser It has the part (304), It is characterized by the above-mentioned.

  In this configuration, for example, if an air heat exchanger (401) is used, it is possible to operate using cold air, and if the underground heat exchanger (21) is used, underground heat is used. Driving becomes possible.

In addition, the fifth invention,
In the heat pump of the first invention,
The refrigerant circuit (10) includes an expansion mechanism (70) and a four-way switching valve (303) for reversibly switching the refrigerant circulation direction,
Between the four-way switching valve (303) and the expansion mechanism (70), the heat source side heat exchanger (80) and an air heat exchanger (series) connected to the heat source side heat exchanger (80) ( 401).

  In this configuration, for example, if the refrigerant is circulated in the refrigerant circuit (10) so that the use side heat exchanger (60) functions as an evaporator, the heat source side heat exchanger (80) hardly exchanges heat. In the air heat exchanger (401), heat exchange with air is performed.

  Further, when the refrigerant is circulated in the refrigerant circuit (10) so that the use side heat exchanger (60) functions as a condenser, for example, an air heat exchanger (401) is installed outside and the outside air temperature When the temperature is lower than the temperature, the air heat exchanger (401) hardly exchanges heat, but the heat source side heat exchanger (80) performs heat exchange. On the other hand, when the outside air temperature is higher than the underground temperature, heat exchange is performed in both the air heat exchanger (401) and the heat source side heat exchanger (80).

In addition, the sixth invention,
In the heat pump of the first invention,
It is provided between the main body pipe (22) and the auxiliary heat exchanging part (25), and conveys the heat medium evaporated in the auxiliary heat exchanging part (25) to the underground heat exchanging part (21). A transport device (201);
For cooling, which is provided in the main body pipe (22), extends to the bottom of the main body pipe (22), and introduces the liquid heat medium from the auxiliary heat exchange section (25) to the bottom of the main body pipe (22). A liquid pipe (202),
The refrigerant circuit (10) is characterized in that the refrigerant circulates so that the heat source side heat exchanger (80) functions as a condenser and the use side heat exchanger (60) functions as an evaporator. To do.

  In this configuration, the heat source side heat exchanger (80) functions as a condenser, and the use side heat exchanger (60) functions as an evaporator. Therefore, the heat pump can be used as a system (for example, a cooling system) that uses the cold in the ground.

In addition, the seventh invention,
In the heat pump of the first invention,
Conveyance that is provided between the main pipe (22) and the auxiliary heat exchange section (25) and conveys the heat medium evaporated in the auxiliary heat exchange section (25) to the underground heat exchange section (21) A device (201);
For cooling, which is provided in the main body pipe (22), extends to the bottom of the main body pipe (22), and introduces the liquid heat medium from the auxiliary heat exchange section (25) to the bottom of the main body pipe (22). Liquid piping (202),
A heating liquid pipe (23) provided in the main body pipe (22), for introducing the liquid heat medium into the inner peripheral surface of the main body pipe (22) from the auxiliary heat exchange section (25);
It is provided with.

  In this configuration, the heat source side heat exchanger (80) can be used as both an evaporator and a condenser. That is, this heat pump can constitute a heat pump (for example, an air conditioning system) capable of an operation using underground heat and an operation using cold heat.

Further, the eighth invention is
In the heat pump according to any one of the first to fourth and seventh inventions,
The underground heat exchange section (21)
A liquid pipe (23) provided on an upper part of the main body pipe (22), for introducing the liquid heat medium into the main body pipe (22) from the auxiliary heat exchange section (25);
A gas pipe (24) for introducing a gaseous heat medium in the main body pipe (22) into the connected sub heat exchange section (25);
A diffusion plate (504) that receives the liquid heat medium introduced from the liquid pipe (23) and diffuses it to the inner peripheral surface of the main body pipe (22);
It is characterized by having.

In addition, the ninth invention,
In the heat pump of the eighth invention,
The main body pipe (22) is characterized in that a circumferential groove (507) is formed on an inner peripheral surface thereof.

The tenth aspect of the invention is
In the heat pump of the eighth invention,
A plurality of the diffusion plates (504) are provided at intervals in the longitudinal direction of the main body tube (22).

The eleventh invention
In the heat pump according to any one of the first to fourth and seventh inventions,
The underground heat exchange part (21) is provided with a spiral liquid pipe (23) for introducing the liquid heat medium from the auxiliary heat exchange part (25) in the main body pipe (22),
The liquid pipe (23) is provided with a plurality of outflow holes (502) for introducing the liquid heat medium into the inner peripheral surface of the main body pipe (22).

In addition, the twelfth invention
In the heat pump according to any one of the first to fourth and seventh inventions,
The underground heat exchanging part (21) is a liquid that introduces the liquid heat medium from the auxiliary heat exchanging part (25) to the inner peripheral surface of the main body pipe (22) above the main body pipe (22). With piping (23)
The liquid pipe (23) is branched into a plurality of branch pipes (501) in the main body pipe (22).

The thirteenth invention
In the heat pump of the twelfth invention,
The branch pipe (501) has a plurality of types of lengths,
Each branch pipe (501) introduces the liquid heat medium into the inner peripheral surface of the main body pipe (22) from the tip.

In addition, the fourteenth invention
In the heat pump of the twelfth invention,
Each branch pipe (501) has an extending part (503) extending in the longitudinal direction of the main body pipe (22) along the inner peripheral surface of the main body pipe (22),
Each extending portion (503) is provided with a plurality of outflow holes (502) for introducing the liquid heat medium on the inner peripheral surface of the main body tube (22).

  In these configurations, the inner peripheral surface of the main body tube (22) can be uniformly wetted with a liquid heat medium.

The fifteenth invention
In any one of the first to fourteenth inventions,
A plurality of the underground heat exchange sections (21) are provided,
Each underground heat exchanging part (21) is connected to one sub heat exchanging part (25) in parallel by piping.

  In this configuration, ground heat or cold is collected by the plurality of underground heat exchange units (21).

In addition, the sixteenth invention
An underground heat exchanger that collects heat from soil,
A heat medium is enclosed inside the tubular body tube (22), and a ground heat exchanging section (21) that changes the phase of the heat medium by collecting heat from the soil in the ground,
Provided in the heat source unit (30) that houses the heat source side heat exchanger (80) of the heat pump, connected to the underground heat exchange unit (21), the heat medium is introduced, and the heat medium performs heat exchange. An auxiliary heat exchange section (25) to perform,
It is provided with.

  In this configuration, since the auxiliary heat exchanger (25) is provided in the heat source unit (30), even if the pipe (11) constituting the refrigerant circuit (10) is damaged, the refrigerant in the pipe (11) Lubricating oil etc. will remain in the heat source machine (30).

In addition, the seventeenth invention
In the underground heat exchanger of the sixteenth invention,
The underground heat exchange section (21)
A liquid pipe (23) provided on an upper part of the main body pipe (22), for introducing the liquid heat medium into the main body pipe (22) from the auxiliary heat exchange section (25);
A gas pipe (24) for introducing a gaseous heat medium in the main body pipe (22) into the connected heat exchange section (27, 28);
A diffusion plate (504) that receives the liquid heat medium introduced from the liquid pipe (23) and diffuses it to the inner peripheral surface of the main body pipe (22);
It is characterized by having.

The eighteenth invention
In the underground heat exchanger of the seventeenth invention,
The main body pipe (22) is characterized in that a circumferential groove (507) is formed on an inner peripheral surface thereof.

The nineteenth invention
In the underground heat exchanger of the seventeenth invention,
A plurality of the diffusion plates (504) are provided at intervals in the longitudinal direction of the main body tube (22).

In addition, the twentieth invention
In the underground heat exchanger of the sixteenth invention,
The underground heat exchange part (21) is provided with a spiral liquid pipe (23) for introducing the liquid heat medium from the auxiliary heat exchange part (25) in the main body pipe (22),
The liquid pipe (23) is provided with a plurality of outflow holes (502) for introducing the liquid heat medium into the inner peripheral surface of the main body pipe (22).

The twenty-first invention
In the underground heat exchanger of the sixteenth invention,
The underground heat exchanging part (21) is a liquid that introduces the liquid heat medium from the auxiliary heat exchanging part (25) to the inner peripheral surface of the main body pipe (22) above the main body pipe (22). With piping (23)
The liquid pipe (23) is branched into a plurality of branch pipes (501) in the main body pipe (22).

The twenty-second invention
In the underground heat exchanger of the twenty-first invention,
The branch pipe (501) has a plurality of types of lengths,
Each branch pipe (501) introduces the liquid heat medium into the inner peripheral surface of the main body pipe (22) from the tip.

The twenty-third invention
In the underground heat exchanger of the twenty-first invention,
Each branch pipe (501) has an extending part (503) extending in the longitudinal direction of the main body pipe (22) along the inner peripheral surface of the main body pipe (22),
Each extending portion (503) is provided with a plurality of outflow holes (502) for introducing the liquid heat medium on the inner peripheral surface of the main body tube (22).

  According to these inventions, it becomes possible to uniformly wet the inner peripheral surface of the main body tube (22) with the liquid heat medium.

  According to the first invention, the refrigerant, lubricating oil, etc. in the refrigerant circuit (10) leaking from the damaged pipe (11) remains in the heat source unit (30), so that the refrigerant, lubricating oil, etc. flow into the soil. Can not be. That is, the present invention can provide a heat pump with a smaller environmental load.

  In addition, according to the second invention, the effect of the first invention can be obtained in a heat pump (for example, an air conditioning system) that uses underground heat.

  Further, according to the third invention, the heat medium can be effectively circulated, so that the efficiency of the system is improved.

  In addition, according to the fourth invention, when the system is configured to perform both operation using the underground heat (for example, heating operation) and operation using the cold air (for example, cooling operation), It becomes possible to obtain the effect.

  Moreover, according to 5th invention, even if the function of a utilization side heat exchanger (60) is any of a condenser and an evaporator, a heat source side heat exchanger (80) (underground heat exchange part (21) ) And at least one of the air heat exchanger (401) performs heat exchange. Therefore, an efficient refrigeration cycle can be performed in the refrigerant circuit (10).

  Moreover, according to 6th invention, it becomes possible to acquire the said effect in the heat pump using underground cold.

  Further, according to the seventh aspect of the invention, the system is configured such that both the operation using warm heat (for example, heating operation) and the operation using cold heat (for example, cooling operation) are performed by the underground heat exchange unit (21). Even in such a case, the above-described effect can be obtained.

  Further, according to the eighth to fourteenth aspects, the inner peripheral surface of the main body pipe (22) can be uniformly wetted with a liquid heat medium. It is possible to efficiently evaporate the heat medium.

  According to the fifteenth aspect, the efficiency of the heat pump is improved by providing a plurality of underground heat exchange sections (21).

  In addition, by sharing the sub heat exchange section (25), it is easy to install a plurality of underground heat exchange sections (21). For example, it is conceivable to provide a sub heat exchange section (25) for each underground heat exchange section (21), but in that case, it is necessary to branch the refrigerant circuit (10). Since the refrigerant circuit (10) contains a mixture of gaseous refrigerant and liquid refrigerant, it may be difficult to branch the refrigerant circuit (10). However, if the auxiliary heat exchanging section (25) is shared, such a branch becomes unnecessary, and the system can be easily constructed.

  Further, according to the sixteenth aspect, the refrigerant, lubricating oil, etc. in the refrigerant circuit (10) leaking from the damaged pipe (11) remains in the heat source unit (30), so that the refrigerant, lubricating oil, etc. Can be prevented from flowing into. That is, the present invention can provide a ground heat exchanger with a smaller environmental load.

  Further, according to the seventeenth to twenty-third aspects, the inner peripheral surface of the main body tube (22) can be uniformly wetted with the liquid heat medium, so that the liquid heat medium can be efficiently evaporated. It becomes possible.

FIG. 1 is a system diagram of an air conditioning system according to Embodiment 1 of the present invention. Drawing 2 is a figure showing typically the state where the underground heat exchange part was installed in the ground. FIG. 3 is a system diagram of an air conditioning system according to a modification of the first embodiment. FIG. 4 is a system diagram of an air conditioning system according to Embodiment 2 of the present invention. FIG. 5 is a system diagram of an air conditioning system according to Embodiment 3 of the present invention, and shows a state during heating operation. FIG. 6 is a diagram illustrating a state during the heating operation of the air conditioning system according to the third embodiment of the present invention. FIG. 7 is a system diagram of an air conditioning system according to Embodiment 4 of the present invention. FIG. 8 is a diagram illustrating a heating operation state of the air conditioning system according to the fourth embodiment of the present invention. FIG. 9 is a system diagram of an air conditioning system according to Embodiment 5 of the present invention. FIG. 10 is a system diagram of an air conditioning system according to Embodiment 5 of the present invention, and is a diagram illustrating a heating operation state. FIG. 11 is a cross-sectional view of a modification of the underground heat exchanger. FIG. 12 is a cross-sectional view of the diffusion plate. FIG. 13 is a plan view of the diffusion plate. FIG. 14 is a diagram showing a cross-sectional shape of the groove. FIG. 15 is a diagram for explaining the opening direction of the outflow hole. FIG. 16 is a diagram illustrating the circumferential position of the outflow hole. FIG. 17 is a diagram illustrating the circumferential position of the branch pipe. FIG. 18 is a view showing a modification of the underground heat exchanger of FIG. FIG. 19 is a diagram for explaining the opening direction of the outflow hole. FIG. 20 is a diagram illustrating the circumferential position of the branch pipe. FIG. 21 is a diagram showing a schematic configuration of an air conditioning system having a plurality of underground heat exchange units.

  Hereinafter, embodiments of an air conditioning system will be described as an example of the heat pump of the present invention with reference to the drawings. The following embodiments are essentially preferable examples, and are not intended to limit the scope of the present invention, its application, or its use. In the following description of each embodiment and modification, components having the same functions as those described once will be given the same reference numerals and description thereof will be omitted.

Embodiment 1 of the Invention
<overall structure>
In the first embodiment, an air conditioning system that performs a heating operation using heat collected from the ground will be described. FIG. 1 is a system diagram of an air conditioning system (1) according to Embodiment 1 of the present invention. As shown in FIG. 1, the air conditioning system (1) includes a refrigerant circuit (10) and a ground heat exchanger (20). This underground heat exchanger (20) is a heat exchanger that collects heat from underground. The refrigerant circuit (10) includes a compressor (50), an indoor heat exchanger (60) (use side heat exchanger), an expansion valve (70) and a heat source side heat exchanger (80). 11) Connected. The refrigerant circuit (10) is filled with refrigerant. The heat source side heat exchanger (80) exchanges heat between the refrigerant in the refrigerant circuit (10) and a heat medium (described later) in the underground heat exchanger (20).

<Configuration of each part>
The compressor (50) sucks and compresses the refrigerant from the suction port, and discharges the compressed refrigerant from the discharge port. Specifically, various compressors such as a scroll compressor can be adopted as the compressor (50). In the refrigerant circuit (10), the compressor (50) has a discharge port connected to the indoor heat exchanger (60) and a suction port connected to the heat source side heat exchanger (80). Since the compressor (50) requires lubricating oil, the compressor (50) is filled with lubricating oil. Part of the lubricating oil circulates in the refrigerant circuit (10) as the compressor (50) is operated.

  The indoor heat exchanger (60) is an air heat exchanger for exchanging heat between the refrigerant and room air. For the indoor heat exchanger (60), for example, a cross fin type fin-and-tube heat exchanger or the like can be employed. In this air conditioning system (1), the indoor heat exchanger (60) is incorporated in a so-called indoor unit (40) disposed in a room that performs air conditioning. In the refrigerant circuit (10), one end of the indoor heat exchanger (60) is connected to the discharge port of the compressor (50) as described above, and the other end is connected to the expansion valve (70). Yes. And when heating, the heat | fever of the high pressure refrigerant | coolant which flowed into the indoor heat exchanger (60) from the compressor (50) is radiated to indoor air. An indoor fan (not shown) is installed in the vicinity of the indoor heat exchanger (60). The indoor fan blows conditioned air into the room.

  The expansion valve (70) has an inflow hole connected to the indoor heat exchanger (60), expands the refrigerant flowing in from the indoor heat exchanger (60), reduces the pressure to a predetermined pressure, and then heats the heat source side heat. Drain to exchanger (80). The expansion valve (70) is an example of the expansion mechanism of the present invention.

  The heat source side heat exchanger (80) exchanges heat with a heat medium (described later) in the underground heat exchanger (20). The configuration of the heat source side heat exchanger (80) will be described later.

  The compressor (50), the expansion valve (70), and the heat source side heat exchanger (80) described above are disposed in one casing and are installed outdoors as a so-called outdoor unit (30). This outdoor unit (30) is an example of the heat source unit of the present invention. Since the arrangement of the heat source side heat exchanger (80) has characteristics, this point will also be described in detail later.

  The underground heat exchanger (20) collects heat from the soil and exchanges heat with the heat source side heat exchanger (80). Hereinafter, the configuration of the underground heat exchanger (20) will be described in detail.

<Configuration of underground heat exchanger (20)>
The underground heat exchanger (20) includes an underground heat exchange part (21) and a sub heat exchange part (25). The underground heat exchange section (21) and the sub heat exchange section (25) are connected to each other by piping. In the underground heat exchanger (20), a predetermined amount of carbon dioxide is sealed as a heat medium. As will be described later, this heat medium evaporates due to underground heat in the underground heat exchange section (21) and condenses in the auxiliary heat exchange section (25).

−Ground heat exchanger (21) −
The underground heat exchanger (21) is buried in the ground and collects heat from the soil. The soil here is a concept including various strata. For example, FIG. 2 is a diagram schematically showing a state in which the underground heat exchange section (21) is installed in the ground. As shown in FIG. 2, the formation includes a layer mainly composed of earth and sand, a layer containing earth and sand, a layer mainly containing water, and a bedrock in which rocks are continuously distributed. Etc. This underground heat exchange part (21) may be installed in any formation. FIG. 2 shows a state in which the underground heat exchange section (21) is installed across each of these layers. For example, the underground heat exchange section (21) performs heat exchange in only one of the formations. You may install as follows. In FIG. 2, “HP” indicates a main part of the air conditioning system (1) (a part other than the underground heat exchange part (21)).

  Specifically, as shown in FIG. 1, the underground heat exchange section (21) includes a main body pipe (22), a liquid pipe (23), and a gas pipe (24).

  The main body pipe (22) is formed in a tubular shape whose both ends are closed, and is buried vertically in the ground. In this example, the main body pipe (22) is formed of a steel pipe having a length of about 5 m. When embedding the main pipe (22), it is ideal to embed it vertically in the ground, but a certain degree of inclination is allowed. In this example, the main body pipe (22) is embedded so that the lower end thereof reaches about 10 m.

  The liquid pipe (23) is a pipe for returning the liquid heat medium accumulated in the sub heat exchange section (25) into the main body pipe (22). In this example, the liquid pipe (23) is inserted into the main body pipe (22) from the upper side of the main body pipe (22) (the side that becomes the ground surface side when the main body pipe (22) is embedded), and one end of the liquid pipe (23) is inserted. It is connected to the auxiliary heat exchanger (25). The other end of the liquid pipe (23) opens into the main body pipe (22) above the main body pipe (22).

  The gas pipe (24) is a pipe for sending the gaseous heat medium in the main body pipe (22) into the sub heat exchange section (25). This gas pipe (24) is also inserted into the main body pipe (22) from the upper side of the main body pipe (22), and one end of the gas pipe (24) is connected to the auxiliary heat exchange section (25). . The other end of the gas pipe (24) opens in the upper space in the main body pipe (22). The connection between the liquid pipe (23) and the gas pipe (24) and the auxiliary heat exchange section (25) will be described in detail later.

−Sub-heat exchanger (25) −
In the auxiliary heat exchange section (25), the gaseous heat medium evaporated in the underground heat exchange section (21) is introduced through the gas pipe (24), and the gaseous heat medium and the heat source side heat Heat is exchanged with the refrigerant in the exchanger (80). In this example, the auxiliary heat exchange part (25) is a sealed container. And the auxiliary heat exchange part (25) is installed in the outdoor unit (30).

  A gas pipe (24) is connected to the auxiliary heat exchange section (25), and the gas pipe (24) is located above the auxiliary heat exchange section (25) in the installed state of the auxiliary heat exchange section (25). (Referred to below as the upper surface side for convenience of description). Thereby, as will be described later, the heat medium evaporated in the main body tube (22) and turned into a gaseous state is introduced into the sub heat exchange section (25).

  In the sub heat exchanger (25), the heat source side heat exchanger (80) is arranged in the space on the upper surface side. The heat source side heat exchanger (80) exchanges heat between the gaseous heat medium and the refrigerant in the refrigerant circuit (10) in the sub heat exchange section (25). Specifically, since the liquid refrigerant flows into the heat source side heat exchanger (80), the refrigerant in the heat source side heat exchanger (80) is the gaseous heat in the sub heat exchanger (25). It absorbs heat from the medium and evaporates. At this time, the heat medium in the auxiliary heat exchange section (25) condenses and becomes liquid and becomes the lower side in the installed state of the auxiliary heat exchange section (25) (hereinafter, the bottom side for convenience of explanation) Will be accumulated).

  In addition, a liquid pipe (23) is inserted into the auxiliary heat exchange section (25) from the bottom surface side, and the liquid pipe (23) is opened at the bottom face in the auxiliary heat exchange section (25). As a result, the liquid pipe (23) can cause the liquid heat medium accumulated in the sub heat exchange section (25) to flow into the main body pipe (22).

  The type of the heat source side heat exchanger (80) is not particularly limited. For example, the heat source side heat exchanger (80) can employ various types such as a so-called plate heat exchanger.

<Driving operation>
In the present embodiment, when the compressor (50) is put into an operating state, the compressed refrigerant (gas refrigerant) is discharged from the discharge port of the compressor (50). The refrigerant discharged from the compressor (50) is sent to the indoor heat exchanger (60). And the refrigerant | coolant which flowed into the indoor heat exchanger (60) radiates heat | fever to indoor air with an indoor heat exchanger (60). In this indoor heat exchanger (60), indoor air is heated, and the heated indoor air is sent back indoors by the indoor fan. The refrigerant radiated by the indoor heat exchanger (60) is sent to the expansion valve (70). The refrigerant that has flowed into the expansion valve (70) is reduced in pressure when passing through the expansion valve (70), becomes liquid, and flows into the heat source side heat exchanger (80). In the refrigerant circuit (10), part of the lubricating oil for the compressor (50) circulates with the operation of the compressor (50).

  At this time, in the main body pipe (22), the heat medium evaporates into a gaseous state by exchanging heat with the inner peripheral surface of the main body pipe (22) and the liquid heat medium. That is, the main body pipe (22) collects heat from the soil in the ground to change the phase of the heat medium. The main body tube (22) thus deprived of heat by the heat medium collects heat from the soil, and thereby the heat of the main body tube (22) is supplemented.

  On the other hand, the gaseous heat medium flows into the auxiliary heat exchange section (25) via the gas pipe (24). As described above, since the liquid refrigerant flows into the heat source side heat exchanger (80), the refrigerant in the heat source side heat exchanger (80) is in a gaseous state in the sub heat exchange section (25). It absorbs heat from the heat medium and evaporates. As a result, the heat medium in the auxiliary heat exchanging section (25) condenses and becomes liquid and accumulates on the bottom surface side of the auxiliary heat exchanging section (25). That is, the heat source side heat exchanger (80) exchanges heat with the heat medium by using the phase change of the heat medium introduced into the sub heat exchange section (25).

  The liquid heat medium accumulated on the bottom surface of the sub heat exchange section (25) is introduced from the upper side of the main body pipe (22) into the main body pipe (22) through the liquid pipe (23). The heat medium introduced into the main body pipe (22) flows along the inner peripheral surface of the main body pipe (22) toward the lower side of the main body pipe (22). As described above, the liquid heat medium flows along the inner peripheral surface of the main body tube (22), so that the heat medium exchanges heat with the inner peripheral surface and evaporates again. The evaporated heat medium flows into the auxiliary heat exchange part (25) through the gas pipe (24). That is, in the underground heat exchanger (20), the heat medium naturally circulates.

  Generally, pressure loss occurs in the gas pipe (24) or the like, so it is considered that the heat medium cannot be circulated sufficiently depending on the pressure in the main pipe (22). However, since there is a sufficient head difference (H) between the underground heat exchange section (21) and the sub heat exchange section (25), the heat medium can be easily circulated. 1 and the like, Pe is the pressure (evaporation pressure) of the heat medium in the main body pipe (22), Pc is the pressure (condensation pressure) of the heat medium in the auxiliary heat exchange section (25), and ΔP is the gas pipe. It is the pressure loss in (24).

  The above operation is repeated, and in the refrigerant circuit (10), the heat source side heat exchanger (80) functions as an evaporator, and the use side heat exchanger (60) functions as a condenser.

<Effect in this embodiment>
As described above, in the present embodiment, the auxiliary heat exchange unit (25) is provided in the outdoor unit (30) (heat source unit). Therefore, even if the pipe (11) constituting the refrigerant circuit (10) is damaged, the refrigerant, the lubricating oil, and the like flowing out from the damaged pipe (11) remain in the outdoor unit (30). Therefore, in this embodiment, it is possible to prevent refrigerant, lubricating oil, and the like flowing out from the damaged pipe (11) from flowing into the soil. That is, this embodiment can provide an air conditioning system (heating system) with a smaller environmental load.

  Further, since the heat medium naturally circulates between the underground heat exchange section (21) and the auxiliary heat exchange section (25), no power is required for heat collection from the underground. In addition, since the underground heat exchanger (20) is configured by being divided into the underground heat exchanger (21) and the auxiliary heat exchanger (25), the structure of the underground heat exchanger (21) is simplified.

<< Modification of Embodiment 1 >>
For example, when the natural circulation of the heat medium cannot be sufficiently performed due to the large pressure loss, the heat medium evaporated in the underground heat exchange part (21) is removed from the sub heat exchange part (25 ) May be provided with a gas pump (201) (conveying device). FIG. 3 is a system diagram of an air conditioning system according to a modification of the first embodiment. In this example, as shown in FIG. 3, a gas pump (201) is provided in the middle of the gas pipe (24). In FIG. 3, Hmax is the head difference, and Hpump is the pressure increase due to the gas pump (201).

<< Embodiment 2 of the Invention >>
In Embodiment 2 of the present invention, an air conditioning system capable of cooling operation will be described. FIG. 4 is a system diagram of an air conditioning system (2) according to Embodiment 2 of the present invention. This air-conditioning system (2) has a gas pump (201) added to the air-conditioning system (1) of the first embodiment, and is changed to the configuration of the auxiliary heat exchange unit (25) and the underground heat exchange unit (21). Is added.

  Specifically, the gas pump (201) is provided in the middle of the gas pipe (24) so as to convey the gaseous heat medium in the auxiliary heat exchange part (25) into the underground heat exchange part (21). It has become. Therefore, in this example, the gas pipe (24) is disposed so as to open in a space on the upper surface side in the sub heat exchange section (25).

  The heat source side heat exchanger (80) exchanges heat with the liquid heat medium in the sub heat exchange section (25). In this example, the heat source side heat exchanger (80) is disposed facing the bottom surface of the sub heat exchange section (25) and comes into contact with the liquid heat medium accumulated in the sub heat exchange section (25). Yes.

  In the underground heat exchange section (21), unlike the first embodiment, a cooling liquid pipe (202) is provided instead of the liquid pipe (23). The cooling liquid pipe (202) is inserted into the main body pipe (22) from the upper side of the main body pipe (22), and one end thereof is connected to the sub heat exchange section (25). The other end of the cooling liquid pipe (202) extends to the vicinity of the lower surface of the main pipe (22). The cooling liquid pipe (202) is arranged in this way because the cooling liquid pipe (202) conveys the liquid heat medium accumulated at the bottom of the main body pipe (22) to the sub heat exchange section (25). It is to do.

<Driving operation>
In this air conditioning system (2), before the start of operation, in the underground heat exchanger (21), the heat medium is cooled on the inner peripheral surface of the main body pipe (22) to become a liquid, and the bottom of the main body pipe (22) It collects in. Further, a gaseous heat medium is also present in the auxiliary heat exchange section (25). Here, in order to perform the cooling operation in the air conditioning system (2), the compressor (50) and the gas pump (201) are put into operation.

  When the gas pump (201) is in an operating state, the gaseous heat medium in the auxiliary heat exchange unit (25) is conveyed into the underground heat exchange unit (21). Then, the pressure in the main body pipe (22) rises, and the liquid heat medium accumulated in the main body pipe (22) passes through the cooling liquid pipe (202) and is transported into the auxiliary heat exchange section (25). Thus, it accumulates at the bottom of the auxiliary heat exchange section (25).

  On the other hand, when the compressor (50) is put into operation, the compressed refrigerant (gas refrigerant) is discharged from the discharge port of the compressor (50). The refrigerant discharged from the compressor (50) is sent to the heat source side heat exchanger (80). In the heat source side heat exchanger (80), the liquid heat medium in the heat source side heat exchanger (80) and the gaseous heat medium in the sub heat exchanger (25) exchange heat. Thereby, the gas refrigerant which has distribute | circulated the inside of the heat source side heat exchanger (80) condenses. That is, in the heat source side heat exchanger (80), the heat medium and the refrigerant exchange heat using the phase change of the heat medium introduced into the sub heat exchange section (25).

  The refrigerant condensed in the heat source side heat exchanger (80) is introduced into the expansion valve (70), decompressed by the expansion valve (70), and then introduced into the indoor heat exchanger (60). The refrigerant flowing into the indoor heat exchanger (60) absorbs heat from the indoor air and evaporates. Thereby, indoor air is cooled in the indoor heat exchanger (60), and the cooled indoor air is sent back into the room by the indoor fan. The refrigerant evaporated in the indoor heat exchanger (60) is introduced into the suction port of the compressor (50). The compressor (50) sucks and compresses the refrigerant and discharges it again to the heat source side heat exchanger (80).

  On the other hand, the heat medium that has exchanged heat with the refrigerant in the heat source side heat exchanger (80) evaporates. The evaporated heat medium accumulates in the space in the sub heat exchange section (25). Then, the gaseous heat medium accumulated in the space is conveyed to the underground heat exchange section (21) by the gas pump (201). The heat medium conveyed to the underground heat exchange part (21) dissipates heat and condenses on the inner peripheral surface of the main body pipe (22). That is, also in this example, the underground heat exchanging part (21) collects heat from the soil in the ground to change the phase of the heat medium.

<Effect in this embodiment>
As described above, even when the air conditioning system is configured to perform cooling, the auxiliary heat exchange unit (25) can be provided in the outdoor unit (30) (heat source unit) as in the first embodiment. Therefore, also in this embodiment, even if the pipe (11) constituting the refrigerant circuit (10) is damaged, it is possible to prevent refrigerant, lubricating oil, etc. in the pipe (11) from flowing into the soil. it can. That is, this embodiment can provide an air conditioning system (cooling system) with a smaller environmental load.

<< Embodiment 3 of the Invention >>
In Embodiment 3 of the present invention, an air conditioning system capable of both heating operation and cooling operation will be described. FIG. 5 is a system diagram of an air conditioning system (3) according to Embodiment 3 of the present invention. Moreover, FIG. 6 is a figure which shows the state at the time of heating operation of an air conditioning system (2). As shown in FIG. 5 and the like, the air conditioning system (3) includes, in addition to the air conditioning system (1) of the first embodiment, first and second heat source side heat exchange units (301, 302), a four-way switching valve (303), a refrigerant. A switching unit (304) and a gas pump (201) (conveyance device) are added.

  Moreover, the underground heat exchanger (20) is changing the underground heat exchanger (20) of Embodiment 1 so that it can be used for both heating operation and cooling operation. Specifically, in addition to the liquid pipe (23) (hereinafter also referred to as a heating liquid pipe) used during heating, a cooling liquid pipe (202) (see Embodiment 2) is added.

<First and second heat source side heat exchange sections (301, 302)>
In this embodiment, the heat source side heat exchanger (80) is comprised by the 1st, 2nd heat source side heat exchange part (301,302). The 1st heat source side heat exchange part (301) has the same function as the heat source side heat exchanger (80) of Embodiment 1. That is, in the first heat source side heat exchange section (301), the gaseous heat medium and the refrigerant in the refrigerant circuit (10) exchange heat. Moreover, the 2nd heat source side heat exchange part (302) has a function similar to the heat source side heat exchanger (80) of Embodiment 2. FIG. That is, in the second heat source side heat exchanging section (302), the liquid heat medium in the sub heat exchanging section (25) and the refrigerant in the refrigerant circuit (10) exchange heat. The second heat source side heat exchanging part (302) is also arranged so as to face the bottom surface of the sub heat exchanging part (25) and comes into contact with the liquid heat medium accumulated in the sub heat exchanging part (25). .

<Four-way selector valve (303)>
The four-way switching valve (303) includes first to fourth ports (P1,..., P4). The four-way selector valve (303) is in a first state in which the first port (P1) and the fourth port (P4) communicate with each other and the second port (P2) and the third port (P3) communicate with each other. (The state shown in FIG. 5), the first port (P1) and the second port (P2) communicate with each other, and the third port (P3) and the fourth port (P4) communicate with each other ( The state shown in FIG. 6 can be switched. In this example, the four-way selector valve (303) has a first port (P1) connected to the indoor heat exchanger (60) and a second port (P2) connected to the discharge port of the compressor (50). Yes.

<Refrigerant switching part (304)>
The refrigerant switching unit (304) includes first to sixth on-off valves (311,..., 316) and first and second flow rate adjusting valves (317, 318).

  The first and second on-off valves (311, 312) are valves for switching the heat exchange unit to be used between the heating operation and the cooling operation. In the air conditioning system (3), the first heat source side heat exchange unit (301) is used during the heating operation, and the second heat source side heat exchange unit (302) is used during the cooling operation. Specifically, in the refrigerant circuit (10), the third port (P3) of the four-way switching valve (303) is connected to one end of the first heat source side heat exchange section (301) via the first on-off valve (311). And connected. The third port (P3) is also connected to one end of the second heat source side heat exchange section (302) via the second opening / closing valve (312). By connecting the first and second heat source side heat exchange sections (301, 302) and the first and second on-off valves (311, 312) as shown in FIG. 5, the first on-off valve (311) is closed and When the 2 on-off valve (312) is opened, the second heat source side heat exchange section (302) is connected to the refrigerant circuit (10) (see FIG. 5). Further, when the first opening / closing valve (311) is opened and the second opening / closing valve (312) is closed, the first heat source side heat exchange section (301) is connected to the refrigerant circuit (10) (FIG. 6).

  The third and fourth open / close valves (313, 314) are valves for switching the liquid pipe to be used between the heating operation and the cooling operation. Specifically, in this air conditioning system (3), the heating liquid pipe (23) is used during the heating operation, and the cooling liquid pipe (202) is used during the cooling operation. In this example, as shown in FIG. 5, the heating liquid pipe (23) is connected to the auxiliary heat exchange section (25) via the third on-off valve (313), and the cooling liquid pipe (202) is It is connected to the auxiliary heat exchange section (25) via the fourth open / close valve (314). By piping in this way, the third on-off valve (313) is closed and the fourth on-off valve (314) is opened, so that only the cooling liquid pipe (202) among these liquid pipes The heat medium flows (see FIG. 5). Further, by opening the third on-off valve (313) and closing the fourth on-off valve (314), the heat medium flows only to the heating liquid pipe (23) among these liquid pipes ( (See FIG. 6).

  The fifth and sixth open / close valves (315, 316) are configured to switch the flow path of the gaseous heat medium between the heating operation and the cooling operation. Specifically, as shown in FIG. 5, when the fifth open / close valve (315) is closed and the sixth open / close valve (316) is opened, the suction port of the gas pump (201) is connected to the auxiliary heat exchange section (25 And the discharge port is connected to the gas pipe (24) via the first flow rate adjustment valve (317). Thereby, the gaseous heat medium in a subheat exchange part (25) can be conveyed to a main body pipe | tube (22) with a gas pump (201). At this time, the flow rate of the heat medium can be adjusted by adjusting the opening degree of the first and second flow rate adjusting valves (317, 318).

  When the fifth open / close valve (315) is opened and the sixth open / close valve (316) is closed, the main body pipe (22) and the auxiliary heat exchanging portion (25) are connected to the first flow rate adjusting valve (317). Will be connected to each other. Thereby, the gaseous heat medium in a main body pipe | tube (22) can be made to flow in into a subheat exchange part (25). Also at this time, the flow rate of the heat medium can be adjusted by adjusting the opening degree of the first and second flow rate adjusting valves (317, 318).

  With this configuration, the air heat exchanger (401) functions as a condenser, and the indoor heat exchanger (60) functions as an evaporator. The part (304) has a second circulating refrigerant so that the heat source side heat exchanger (80) functions as an evaporator and the indoor heat exchanger (60) (use side heat exchanger) functions as a condenser. The operation mode (heating operation) is switched. That is, the refrigerant switching unit (304) of the present embodiment is an example of the switching unit of the present invention.

<Driving operation>
To perform the cooling operation in the air conditioning system (4), the four-way switching valve (303) is switched to the first state. In addition, the first open / close valve (311) is closed and the second open / close valve (312) is opened, and the second heat source side heat exchange section (302) is connected to the refrigerant circuit (10) (see FIG. 5). ). Further, the third open / close valve (313) is closed and the fourth open / close valve (314) is opened so that the heat medium can flow through the cooling liquid pipe (202). Further, the fifth opening / closing valve (315) is closed and the sixth opening / closing valve (316) is opened so that the suction port of the gas pump (201) is connected to the auxiliary heat exchange section (25).

  In this state, the compressor (50) and the gas pump (201) are put into operation. Then, the cooling operation is performed in the same manner as the air conditioning system (2) of the second embodiment.

  Moreover, in order to perform heating operation in the air conditioning system (4), the four-way switching valve (303) is switched to the second state. Further, the first on-off valve (311) is opened, and the second on-off valve (312) is closed, and the first heat source side heat exchange section (301) is connected to the refrigerant circuit (10) (see FIG. 6). ). Further, the third opening / closing valve (313) is opened and the fourth opening / closing valve (314) is closed so that the heat medium can flow through the heating liquid pipe (23). Further, with the fifth open / close valve (315) opened and the sixth open / close valve (316) closed, the main body pipe (22) and the auxiliary heat exchanging section (25) are connected to the first flow control valve (317). To be connected to each other through. In this state, the compressor (50) is put into operation. Then, the heating operation is performed in the same manner as the air conditioning system (1) of the first embodiment.

<Effect in this embodiment>
As described above, when the air conditioning system is configured to perform both the heating operation and the cooling operation, the auxiliary heat exchange unit (25) is placed in the outdoor unit (30) (heat source unit) as in the first embodiment. Can be provided. Therefore, also in this embodiment, even if the pipe (11) constituting the refrigerant circuit (10) is damaged, it is possible to prevent refrigerant, lubricating oil, etc. in the pipe (11) from flowing into the soil. it can. That is, this embodiment can provide an air conditioning system (air conditioning system) with a smaller environmental load.

<< Embodiment 4 of the Invention >>
In Embodiment 4 of the present invention, an air conditioning system capable of both heating operation and cooling operation will be described. FIG. 7 is a system diagram of an air conditioning system (4) according to Embodiment 4 of the present invention. Moreover, FIG. 8 is a figure explaining the heating operation state of an air conditioning system (4). As shown in FIGS. 7 and 8, the air conditioning system (4) of the present embodiment includes an air heat exchanger (401), a four-way switching valve (303), and a refrigerant switch as well as the air conditioning system (1) of the first embodiment. Part (304) is added.

  The air heat exchanger (401) is an air heat exchanger for exchanging heat between the refrigerant in the refrigerant circuit (10) and outdoor air. In this example, the air heat exchanger (401) is provided in the outdoor unit (30). For example, a cross fin type fin-and-tube heat exchanger can be adopted as the air heat exchanger (401).

  The refrigerant switching unit (304) of the present embodiment includes first and second on-off valves (402, 403). The first and second on-off valves (402, 403) are valves for switching the heat exchanger to be used between the heating operation and the cooling operation. This refrigerant | coolant switching part (304) is an example of the switching part of this invention. Specifically, the refrigerant switching unit (304) connects the air heat exchanger (401) to the refrigerant circuit (10), the air heat exchanger (401) functions as a condenser, and the indoor heat exchanger. A first operation mode (cooling operation) in which the refrigerant circulates in the refrigerant circuit (10) so that (60) functions as an evaporator, and a heat source side heat exchanger (80) is connected to the refrigerant circuit (10) The refrigerant circulates through the refrigerant circuit (10) so that the heat source side heat exchanger (80) functions as an evaporator and the indoor heat exchanger (60) (use side heat exchanger) functions as a condenser. The operation mode (heating operation) is switched. That is, in this air conditioning system (4), the underground heat exchanger (20) is used during the heating operation, and the air heat exchanger (401) is used during the cooling operation.

  In this example, the air heat exchanger (401) has one end connected to the third port (P3) of the four-way switching valve (303) via the first on-off valve (402) as shown in FIG. The other end of the air heat exchanger (401) is connected to the expansion valve (70). The heat source side heat exchanger (80) of the present embodiment is connected to the third port (P3) of the four-way switching valve (303) via the second on-off valve (403). The heat source side heat exchanger (80), the air heat exchanger (401), and the open / close valves (402, 403) are connected as shown in FIG. When the second opening / closing valve (403) is closed, the air heat exchanger (401) is connected to the refrigerant circuit (10) (see FIG. 7). Further, when the first opening / closing valve (402) is closed and the second opening / closing valve (403) is opened, the heat source side heat exchanger (80) is connected to the refrigerant circuit (10), and the underground heat The exchanger (20) becomes available.

<Driving operation>
To perform the cooling operation in the air conditioning system (4), the four-way switching valve (303) is switched to the first state. Further, the first on-off valve (402) is opened and the second on-off valve (403) is closed, and the air heat exchanger (401) is connected to the refrigerant circuit (10) (see FIG. 7). In this state, if the compressor (50) is operated and the refrigerant is circulated in the refrigerant circuit (10), the indoor heat exchanger (60) functions as an evaporator and the air heat exchanger (401) is condensed. Function. Thereby, indoor air is cooled by the indoor heat exchanger (60). That is, the cooling operation is performed in the air conditioning system (4).

  Moreover, in order to perform heating operation in the air conditioning system (4), the four-way switching valve (303) is switched to the second state (see FIG. 8). Further, the first open / close valve (402) is closed and the second open / close valve (403) is opened, and the heat source side heat exchanger (80) is connected to the refrigerant circuit (10) (see FIG. 8). If the compressor (50) is operated in this state and the refrigerant is circulated in the refrigerant circuit (10), the heating operation is performed as in the first embodiment.

<Effect in this embodiment>
As described above, according to the present embodiment, both the heating operation and the cooling operation are possible. And similarly to Embodiment 1, a sub heat exchange part (25) can be provided in an outdoor unit (30) (heat source machine). Therefore, also in this embodiment, even if the pipe (11) constituting the refrigerant circuit (10) is damaged, the refrigerant or lubricating oil in the pipe (11) is prevented from flowing into the soil. be able to. That is, this embodiment can provide an air conditioning system (air conditioning system) with a smaller environmental load.

  In the heating operation, if the outside air temperature is higher than the underground temperature, the air operation may be performed using the air heat exchanger (401).

  In addition, the refrigerant is used so that the heat source side heat exchanger (80) and the air heat exchanger (401) function as an evaporator, and the indoor heat exchanger (60) (use side heat exchanger) functions as a condenser. You may comprise a refrigerant | coolant switching part (304) so that it can switch to the 3rd operation mode which circulates.

<< Embodiment 5 of the Invention >>
In Embodiment 5 of the present invention, an air conditioning system capable of both heating operation and cooling operation will be described. FIG. 9 is a system diagram of an air conditioning system (5) according to Embodiment 5 of the present invention. Moreover, FIG. 10 is a figure explaining the heating operation state of an air conditioning system (5). As shown in FIGS. 9 and 10, the air conditioning system (5) of the fifth embodiment is obtained by changing the connection mode of the air heat exchanger (401) in the air conditioning system (4) of the fourth embodiment. With this change, the first and second on-off valves (402, 403) are no longer needed.

<Air heat exchanger (401)>
Also in this embodiment, the air heat exchanger (401) is accommodated in the outdoor unit (30), and serves to exchange heat between the refrigerant and the outdoor air. The air heat exchanger (401) is connected between the expansion valve (70) and the heat source side heat exchanger (80) in the refrigerant circuit (10). That is, the air heat exchanger (401) is connected in series with the heat source side heat exchanger (80). As described above, when the air heat exchanger (401) and the heat source side heat exchanger (80) are connected, the air heat exchanger (401) is connected to the heat source side heat exchanger ( 80) downstream of the refrigerant flow.

  An outdoor fan (405) is installed in the vicinity of the air heat exchanger (401). The outdoor air that has exchanged heat with the refrigerant is sent out by an outdoor fan (405).

<Driving operation>
First, the operation of the cooling operation will be described. As shown in FIG. 9, in the cooling operation, the four-way switching valve (303) is set to the first state. When the compressor (50) is driven, the refrigerant flows in the direction of the arrow, and the high-temperature and high-pressure gas refrigerant discharged from the compressor (50) flows into the heat source side heat exchanger (80). The temperature of the gas refrigerant in the heat source side heat exchanger (80) is higher than the underground temperature. Therefore, in the underground heat exchanger (20), only the internal heat of the auxiliary heat exchange unit (25) is higher than that of the main body pipe (22), and the gas refrigerant is heated by the heat source side heat exchanger (80). With almost no heat exchange, it passes through the heat source side heat exchanger (80) while maintaining the high pressure and high temperature, and flows into the air heat exchanger (401). Thus, the heat source side heat exchanger (80) hardly exhibits a function as a heat exchanger during the cooling operation.

  In the air heat exchanger (401), high-temperature and high-pressure gas refrigerant exchanges heat with outdoor air. Outdoor air is heated and delivered by an outdoor fan (405). The gas refrigerant condenses into a liquid refrigerant. The liquid refrigerant is sent to the expansion valve (70) and decompressed, and then flows into the indoor heat exchanger (60). In the indoor heat exchanger (60), the liquid refrigerant exchanges heat with room air. The room air is cooled and sent back into the room by an indoor fan. The liquid refrigerant evaporates and is sent again to the compressor (50). Thus, in the cooling operation, a vapor compression refrigeration cycle in which the air heat exchanger (401) functions as a condenser and the indoor heat exchanger (60) functions as an evaporator is performed.

  Next, the heating operation will be described. As shown in FIG. 10, in the heating operation, the four-way switching valve (303) is set to the second state, and the refrigerant flows in the direction of the arrow. In the heating operation, as in the first embodiment, a vapor compression refrigeration cycle in which the indoor heat exchanger (60) functions as a condenser and the heat source side heat exchanger (80) functions as an evaporator is performed. At this time, liquid refrigerant condensed in the indoor heat exchanger (60) and decompressed by the expansion valve (70) flows into the air heat exchanger (401). In the air heat exchanger (401), the outdoor fan (405) is stopped. Therefore, the liquid refrigerant passes through the air heat exchanger (401) and flows into the heat source side heat exchanger (80) with little heat exchange with the outdoor air. Thus, the air heat exchanger (401) hardly performs the function as a heat exchanger during heating operation.

<Effect in this embodiment>
As described above, in the present embodiment, efficient cooling operation is possible by using the underground heat exchanger (20) and the air heat exchanger (401) in combination during cooling.

<< Modification of Embodiment 5 of the Invention >>
In the fifth embodiment, when the outside air temperature is higher than the underground temperature during the heating operation, the air heat exchanger (401) may function as an evaporator.

  When the outside air temperature is higher than the underground temperature, the air heat exchanger (401) that absorbs heat from the outdoor air and evaporates the refrigerant is more suitable for the heat source side heat exchanger (80) that absorbs heat from the underground heat and evaporates the refrigerant. The amount of heat absorbed by the refrigerant is greater than Therefore, in such a case, the air fan (401) may be operated by rotating the outdoor fan (405). Thereby, the energy utilization efficiency of an air conditioning system (5) can be made high.

  In the fifth embodiment, the positions of the heat source side heat exchanger (80) and the air heat exchanger (401) on the refrigerant circuit (10) may be switched.

Embodiment 6 of the Invention
In the sixth embodiment, a modification of the underground heat exchanger (20) will be described. FIG. 11 is a cross-sectional view of a modification of the underground heat exchanger (20).

  <1> The example of FIG. 11A includes a diffusion plate (504) inside the main body tube (22).

  The diffuser plate (504) is a liquid heat medium returned from the liquid pipe (23) into the main body pipe (22) and is liquid so that the inner peripheral surface of the main body pipe (22) is uniformly wet in the circumferential direction. The heat medium is guided to the inner peripheral surface of the main body tube (22). FIG. 12 is a cross-sectional view of the diffusion plate (504). FIG. 13 is a plan view of the diffusion plate (504). The diffusion plate (504) is fixed (for example, welded) in the main body pipe (22) via spacers (not shown) provided at several locations on the outer periphery.

  As can be seen from FIG. 12 and FIG. 13, the liquid heat medium that has fallen from the liquid pipe (23) accumulates in the tray (505) of the diffusion plate (504). The accumulated heat medium overflows from the notch (506) provided at the outer peripheral edge of the tray (505), and wets the inner peripheral surface of the main body pipe (22). As described above, since the notches (506) are provided at a plurality of locations, the inner peripheral surface of the main body tube (22) is uniformly wetted by the liquid heat medium. That is, the liquid heat medium can be efficiently evaporated.

  <2> Also in the example of FIG. 11B, the main body tube (22) includes a diffusion plate (504) inside. A plurality of circumferential grooves (507) are formed on the inner peripheral surface of the main body pipe (22). In this example, these grooves (507) are provided on the downstream side of the liquid heat medium from the diffusion plate (504) (below the diffusion plate (504) when the main body pipe (22) is installed).

  FIG. 14 is a diagram showing a cross-sectional shape of the groove (507). Each groove (507) spreads the liquid heat medium guided from the diffusion plate (504) in the circumferential direction, and more uniformly wets the inner peripheral surface of the main body tube (22) with the liquid heat medium. As a result, the liquid heat medium can be evaporated more efficiently. Moreover, since a plurality of grooves (507) are provided, uniform wetting can be ensured over the entire length of the main body tube (22). The groove (507) may be formed in a spiral shape.

  <3> The example of FIG. 11C includes a plurality of diffusion plates (504) inside the main body tube (22). By doing so, it is possible to ensure uniform wetting over the entire length of the main body tube (22).

  <4> In the example of FIG. 11D, the liquid pipe (23) is formed in a spiral shape, and the liquid pipe (23) is provided with a plurality of outflow holes (502) through which the liquid heat medium flows out. (A portion indicated by a black circle in FIG. 11D). As shown in FIG. 15, each outflow hole (502) is opened toward the inner peripheral surface of the main body pipe (22). Further, as shown in FIG. 11 (D), these outflow holes (502) are arranged so as to be evenly arranged in the longitudinal direction so as to get wet with the liquid heat medium over the entire length of the main body pipe (22). It is. FIG. 16 is a view showing the circumferential position of the outflow hole (502). As shown in the figure, the circumferential position of the outflow holes (502) is not biased in one direction, and in this example, the pitch is equal. By doing so, it is possible to ensure uniform wetting over the entire length and the entire circumference of the main body tube (22).

  <5> In the example of FIG. 11E, the liquid pipe (23) is branched into a plurality of branch pipes (501). The tip of each branch pipe (501) is in contact with the inner peripheral surface of the main body pipe (22). Moreover, FIG. 17 is a figure which shows the circumferential direction position of a branch pipe (501). As shown in the figure, the circumferential direction position of the branch pipe (501) is set so as not to be biased in one direction, and in this example, is equal pitch (90 ° interval). This makes it possible to ensure uniform wetting over the entire circumference of the main body tube (22).

  Moreover, FIG. 18 is a figure which shows the modification of the underground heat exchanger (20) of FIG.11 (E). As shown in FIG. 18, in an example such as FIG. 11E, a mesh (90) along the inner peripheral surface of the main body pipe (22) may be provided. In this example, a plurality of meshes (90) are provided at predetermined intervals in the longitudinal direction of the main body tube (22).

  <6> In the example of FIG. 11 (F), the branch pipe (501) has a plurality of lengths. As shown in the figure, these branch pipes (501) are arranged so that the ends thereof are arranged as evenly as possible in the longitudinal direction so as to get wet with the liquid heat medium over the entire length of the main body pipe (22). . By doing so, it is possible to ensure uniform wetting over the entire length and the entire circumference of the main body tube (22).

  <7> In the example of FIG. 11G as well, the liquid pipe (23) is branched into a plurality of branch pipes (501).

  Each branch pipe (501) has an extending part (503) extending in the longitudinal direction of the main body pipe (22) along the inner peripheral surface of the main body pipe (22). Each extending portion (503) is provided with a plurality of outflow holes (502) through which the liquid heat medium flows out to the inner peripheral surface of the main body tube (22) (FIG. 11G). In black circles). As shown in FIG. 19, each outflow hole (502) opens toward the inner peripheral surface of the main body pipe (22).

  Further, as shown in FIG. 11 (G), these outflow holes (502) are arranged so as to be evenly arranged in the longitudinal direction so as to get wet with the liquid heat medium over the entire length of the main body pipe (22). It is. Moreover, FIG. 20 is a figure which shows the circumferential direction position of the extension part (503). As shown in the drawing, the circumferential position of the extending portion (503) is not biased in one direction, and is an equal pitch (90 °) in this example. By doing so, it is possible to ensure uniform wetting over the entire length and the entire circumference of the main body tube (22).

<< Other Embodiments >>
As shown in FIG. 21, a plurality of underground heat exchanging parts (21) are provided, and the underground heat exchanging parts (21) are connected in parallel to one auxiliary heat exchanging part (25). Two auxiliary heat exchangers (25) may be shared.

  The length of the main body tube (22) is an example. What is necessary is just to set according to conditions, such as the capability required for an installation place or the use side heat exchanger (60), such as making it still longer (for example, 10 m) than the said example.

  Moreover, not only an air-conditioning system but application to a hot water supply system is also possible, for example.

  INDUSTRIAL APPLICABILITY The present invention is useful as an underground heat exchanger that collects heat from soil and a heat pump using the underground heat exchanger.

1 Air conditioning system (heat pump)
DESCRIPTION OF SYMBOLS 10 Refrigerant circuit 21 Underground heat exchange part 22 Main body pipe 23 Liquid piping 25 Sub heat exchange part 30 Outdoor unit (heat source machine)
60 Indoor heat exchanger (use side heat exchanger)
70 Expansion valve (expansion mechanism)
80 Heat source side heat exchanger 201 Gas pump (conveyance device)
304 Refrigerant switching part 401 Air heat exchanger 501 Branch pipe 502 Outflow hole 503 Extension part 504 Diffusion plate 507 Groove

Claims (23)

A heat pump having a refrigerant circuit (10) having a heat source side heat exchanger (80) and a use side heat exchanger (60) and performing a vapor compression refrigeration cycle,
A heat medium is enclosed inside the tubular body tube (22), and a ground heat exchanging section (21) that changes the phase of the heat medium by collecting heat from the soil in the ground,
A sub heat exchange section (25) connected to the underground heat exchange section (21) and introduced with the heat medium;
The main body pipe (22) is buried vertically in the ground,
The auxiliary heat exchanger (25) is provided in a heat source unit (30) that houses the heat source side heat exchanger (80),
The heat pump according to claim 1, wherein the heat source side heat exchanger (80) exchanges heat with the heat medium by using a phase change of the heat medium introduced into the sub heat exchanger (25). The heat pump of claim 1,
The refrigerant circuit (10) is characterized in that the refrigerant circulates so that the heat source side heat exchanger (80) functions as an evaporator and the use side heat exchanger (60) functions as a condenser. Heat pump. The heat pump of claim 2,
A heat pump comprising a transfer device (201) for transferring the heat medium evaporated in the underground heat exchange section (21) to the sub heat exchange section (25). In the heat pump of claim 2 or claim 3,
An air heat exchanger (401) connected to the refrigerant circuit (10) for exchanging heat with air;
The refrigerant circuit (10) includes a first operation mode in which the refrigerant circulates so that the air heat exchanger (401) functions as a condenser and the use side heat exchanger (60) functions as an evaporator. A second operation mode in which the refrigerant circulates so that the heat source side heat exchanger (80) functions as an evaporator and the use side heat exchanger (60) functions as a condenser; and the heat source side heat exchange Refrigerant switching to switch the third operation mode in which the refrigerant circulates so that the heat exchanger (80) and the air heat exchanger (401) function as an evaporator and the use side heat exchanger (60) functions as a condenser The heat pump characterized by having a part (304). The heat pump of claim 1,
The refrigerant circuit (10) includes an expansion mechanism (70) and a four-way switching valve (303) for reversibly switching the refrigerant circulation direction,
Between the four-way switching valve (303) and the expansion mechanism (70), the heat source side heat exchanger (80) and an air heat exchanger (series) connected to the heat source side heat exchanger (80) ( 401). The heat pump of claim 1,
It is provided between the main body pipe (22) and the auxiliary heat exchanging part (25), and conveys the heat medium evaporated in the auxiliary heat exchanging part (25) to the underground heat exchanging part (21). A transport device (201);
For cooling, which is provided in the main body pipe (22), extends to the bottom of the main body pipe (22), and introduces the liquid heat medium from the auxiliary heat exchange section (25) to the bottom of the main body pipe (22). A liquid pipe (202),
The refrigerant circuit (10) is characterized in that the refrigerant circulates so that the heat source side heat exchanger (80) functions as a condenser and the use side heat exchanger (60) functions as an evaporator. Heat pump. The heat pump of claim 1,
Conveyance that is provided between the main pipe (22) and the auxiliary heat exchange section (25) and conveys the heat medium evaporated in the auxiliary heat exchange section (25) to the underground heat exchange section (21) A device (201);
For cooling, which is provided in the main body pipe (22), extends to the bottom of the main body pipe (22), and introduces the liquid heat medium from the auxiliary heat exchange section (25) to the bottom of the main body pipe (22). Liquid piping (202),
A heating liquid pipe (23) provided in the main body pipe (22), for introducing the liquid heat medium into the inner peripheral surface of the main body pipe (22) from the auxiliary heat exchange section (25);
A heat pump comprising: In the heat pump of any one of claims 1 to 4 and claim 7,
The underground heat exchange section (21)
A liquid pipe (23) provided on an upper part of the main body pipe (22), for introducing the liquid heat medium into the main body pipe (22) from the auxiliary heat exchange section (25);
A gas pipe (24) for introducing a gaseous heat medium in the main body pipe (22) into the connected sub heat exchange section (25);
A diffusion plate (504) that receives the liquid heat medium introduced from the liquid pipe (23) and diffuses it to the inner peripheral surface of the main body pipe (22);
A heat pump characterized by comprising: The heat pump of claim 8,
The main body pipe (22) has a circumferential groove (507) formed on an inner peripheral surface thereof. The heat pump of claim 8,
A plurality of the diffusion plates (504) are provided at intervals in the longitudinal direction of the main body tube (22). In the heat pump of any one of claims 1 to 4 and claim 7,
The underground heat exchange part (21) is provided with a spiral liquid pipe (23) for introducing the liquid heat medium from the auxiliary heat exchange part (25) in the main body pipe (22),
The heat pump according to claim 1, wherein the liquid pipe (23) is provided with a plurality of outflow holes (502) for introducing the liquid heat medium into the inner peripheral surface of the main body pipe (22). In the heat pump of any one of claims 1 to 4 and claim 7,
The underground heat exchanging part (21) is a liquid that introduces the liquid heat medium from the auxiliary heat exchanging part (25) to the inner peripheral surface of the main body pipe (22) above the main body pipe (22). With piping (23)
The liquid pipe (23) is branched into a plurality of branch pipes (501) in the main body pipe (22). The heat pump of claim 12,
The branch pipe (501) has a plurality of types of lengths,
Each branch pipe (501) introduces the liquid heat medium from the tip into the inner peripheral surface of the main body pipe (22). The heat pump of claim 12,
Each branch pipe (501) has an extending part (503) extending in the longitudinal direction of the main body pipe (22) along the inner peripheral surface of the main body pipe (22),
Each extension part (503) is provided with a plurality of outflow holes (502) for introducing the liquid heat medium on the inner peripheral surface of the main body pipe (22). The heat pump according to any one of claims 1 to 14,
A plurality of the underground heat exchange sections (21) are provided,
Each underground heat exchange part (21) is pipe-connected in parallel to one sub heat exchange part (25), The heat pump characterized by the above-mentioned. An underground heat exchanger that collects heat from soil,
A heat medium is enclosed inside the tubular body tube (22), and a ground heat exchanging section (21) that changes the phase of the heat medium by collecting heat from the soil in the ground,
Provided in the heat source unit (30) that houses the heat source side heat exchanger (80) of the heat pump, connected to the underground heat exchange unit (21), the heat medium is introduced, and the heat medium performs heat exchange. An auxiliary heat exchange section (25) to perform,
An underground heat exchanger characterized by comprising: The underground heat exchanger according to claim 16,
The underground heat exchange section (21)
A liquid pipe (23) provided on an upper part of the main body pipe (22), for introducing the liquid heat medium into the main body pipe (22) from the auxiliary heat exchange section (25);
A gas pipe (24) for introducing a gaseous heat medium in the main body pipe (22) into the connected heat exchange section (27, 28);
A diffusion plate (504) that receives the liquid heat medium introduced from the liquid pipe (23) and diffuses it to the inner peripheral surface of the main body pipe (22);
An underground heat exchanger characterized by comprising: The underground heat exchanger according to claim 17,
The main body pipe (22) has a groove (507) in the circumferential direction formed on an inner peripheral surface thereof, and is a ground heat exchanger. The underground heat exchanger according to claim 17,
A plurality of the diffusion plates (504) are provided at intervals in the longitudinal direction of the main body pipe (22). The underground heat exchanger according to claim 16,
The underground heat exchange part (21) is provided with a spiral liquid pipe (23) for introducing the liquid heat medium from the auxiliary heat exchange part (25) in the main body pipe (22),
The underground heat exchanger, wherein the liquid pipe (23) is provided with a plurality of outflow holes (502) for introducing the liquid heat medium into the inner peripheral surface of the main body pipe (22). The underground heat exchanger according to claim 16,
The underground heat exchanging part (21) is a liquid that introduces the liquid heat medium from the auxiliary heat exchanging part (25) to the inner peripheral surface of the main body pipe (22) above the main body pipe (22). With piping (23)
The underground heat exchanger is characterized in that the liquid pipe (23) is branched into a plurality of branch pipes (501) in the main body pipe (22). The underground heat exchanger according to claim 21,
The branch pipe (501) has a plurality of types of lengths,
Each branch pipe (501) introduces the liquid heat medium from the tip into the inner peripheral surface of the main body pipe (22). The underground heat exchanger according to claim 21,
Each branch pipe (501) has an extending part (503) extending in the longitudinal direction of the main body pipe (22) along the inner peripheral surface of the main body pipe (22),
Each extension portion (503) is provided with a plurality of outflow holes (502) for introducing the liquid heat medium on the inner peripheral surface of the main body pipe (22). vessel.

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