JP6883186B2 - Heat pump system - Google Patents

Description

The present invention relates to a system using a heat pump cycle that transfers heat by a circulating heat medium, and more particularly to a heat pump system that can utilize geothermal heat together with air heat.

A refrigeration cycle in which work is added to a heat medium and the heat is circulated while repeating phase changes to transfer heat from the low temperature side to the high temperature side has been conventionally used in refrigerators, air conditioners for cooling, and the like. In recent years, the use as a heat pump for heating has also attracted attention from the viewpoint of its efficiency and small environmental load, and nowadays, reduction of carbon dioxide emissions has become a social demand, and such heat pumps are used for existing heating. It is rapidly being introduced as an alternative facility for equipment. As the refrigeration cycle used as a heat pump, a vapor compression refrigeration cycle having an evaporator, a compressor, a condenser and an expansion valve (pressure reducing valve) is generally used.

In a heating / cooling system using such a heat pump, by utilizing geothermal heat with small temperature changes throughout the year, the outside temperature is extremely low when heating is required, or when cooling is required. Various devices have been proposed that can perform stable heating and cooling even when the temperature is high.

Among such conventional heat pump systems, there is one disclosed in Japanese Patent Application Laid-Open No. 2016-200356 as an example of an apparatus that uses an air heat source and an underground heat source in a combined manner.

Japanese Unexamined Patent Publication No. 2016-200356

As shown in the patent document, the conventional heat pump device includes a heat pump that utilizes air heat and a heat pump that utilizes geothermal heat, and drives both heat pumps as necessary to exchange heat such as hot water. It is a mechanism to heat the object. Therefore, although it is excellent in terms of performance, it is equipped with two independent heat pump cycle devices, so it costs more than a device having only one heat pump that uses air heat, such as a general air conditioner (air conditioner). It was inevitable that it would be expensive, and there was a problem that it was difficult to introduce it.

The present invention has been made to solve the above problems, and it is possible to utilize the geothermal heat by additionally incorporating a heat exchange portion with the geothermal heat to the heat pump that utilizes the air heat, and the cost of the entire system. The purpose is to provide a heat pump system that can improve heat exchange performance by utilizing geothermal heat.

The heat pump system according to the present invention includes an indoor heat exchanger that exchanges heat with indoor air for a phase-changeable heat medium, an outdoor heat exchanger that exchanges heat with outdoor air for the heat medium, and the heat of the gas phase. A compressor that compresses the medium to increase the temperature and pressure of the heat medium, an expander that expands the heat medium in the liquid phase to reduce the pressure, and a heat medium flow path between the outdoor heat exchanger and the compressor. Change the connection relationship so that the heat medium leaving the compressor goes to the outdoor heat exchanger in the first flow path connection state, and the heat medium leaving the outdoor heat exchanger goes to the compressor. In a heat pump system including one or a plurality of flow path switching valves that can switch between the second flow path connection state and the second flow path connection state, a predetermined heat that is arranged outdoors and collects underground underground heat. Switching between one or more heat exchangers that enable switching between an underground heat exchanger that exchanges heat between the replacement medium and the heat medium and the flow and non-distribution of the heat medium to the underground heat exchanger. In a state where the underground heat exchanger is provided with a valve and the heat medium is circulated, when the flow path switching valve is in the first flow path connection state, the heat medium is condensed or the heat medium is condensed. When the second flow path is connected to the second flow path connection state, heat exchange is performed to evaporate the heat medium or raise the temperature of the heat medium.

As described above, in the present invention, in addition to the indoor heat exchanger, the outdoor heat exchanger, the compressor, the expander, and the flow path switching valve that realize the heat pump cycle utilizing air heat and the refrigeration cycle. , A flow path in which an underground heat exchanger that enables heat exchange with underground heat is provided, a heat medium is circulated through the underground heat exchanger, and the indoor heat exchanger acts as an evaporator of the heat medium. In the first connection state of the switching valve, the underground heat exchanger is used to condense the heat medium or lower the temperature as in the case of the outdoor heat exchanger, and the indoor heat exchanger condenses the heat medium. In the second connection state of the flow path switching valve that acts as a vessel, the underground heat exchanger is used for evaporation or temperature rise of the heat medium as in the case of the outdoor heat exchanger, so that the indoor side When the heat exchanger works as an evaporator, in addition to being able to release the heat of the heat medium to the ground, which is generally lower than the outside air temperature, to increase the cooling capacity of the heat medium, the indoor heat exchanger works as a condenser. At the time of heating, the heat medium can be heated by the heat of the ground, which is generally higher than the outside air temperature, to increase the heating capacity for the heat medium, and the heat absorption performance and heat dissipation performance of the indoor heat exchanger can be greatly improved. Further, such performance improvement can be realized by adding a geothermal heat exchanger to the heat pump that uses air heat, and the addition of such a geothermal heat exchanger is related to the connection of the heat medium flow path. Adjustment, specifically, by connecting the geothermal heat exchanger part to the heat pump by partially changing the pipeline through which the heat medium in the heat pump using air heat is passed, it is possible to deal with the air heat related to the system introduction. It is possible to minimize the cost increase as compared with the case of a heat pump system that uses only the heat pump system, and it is possible to facilitate the introduction of a heat pump system that can also use geothermal heat.

Further, in the heat pump system according to the present invention, if necessary, the heat exchanger switching valve is provided between the outdoor heat exchanger and the expander, or between the expander and the indoor heat exchanger. The geothermal heat exchanger can switch between a state in which the heat medium can flow and a state in which the heat medium does not intervene in the heat medium flow path.

As described above, in the present invention, the underground heat exchanger is provided at a predetermined position in the heat medium flow path of the heat pump via the heat exchanger switching valve, and is ground in a state where the heat medium is circulated. The medium heat heat exchanger is connected in series with the outdoor heat exchanger, and the heat medium that flows through the outdoor heat exchanger also flows directly to the underground heat exchanger, resulting in indoor heat. During cooling, when the exchanger acts as an evaporator, the outdoor heat exchanger can mainly lower the heat medium temperature, the underground heat exchanger can mainly condense the heat medium, and the indoor heat exchanger can be used. During heating, which works as a condenser, the underground heat exchanger can mainly raise the temperature of the heat medium, and the outdoor heat exchanger can mainly evaporate the heat medium. The load related to heat exchange can be shared with the exchanger, and especially during heating, the underground heat exchanger acts as a preheating heat exchanger in front of the outdoor heat exchanger, and the outdoor heat exchange. As the temperature of the heat medium rises in front of the vessel, the heat exchange in the exposed heat region of the heat medium in the outdoor heat exchanger is reduced, and the heat transfer from air to the heat medium in the outdoor heat exchanger forming the evaporator. The heat exchange performance can be improved by suppressing the loss, such as improving the efficiency of the cooling and heating, and the cooling and heating can be performed efficiently.

Further, the heat pump system according to the present invention has one end connectable to the underground heat exchanger and the other end connectable to the compressor inlet side as needed, and heat is required. It is possible to switch between a bypass flow path through which the medium flows, a state in which the other end of the bypass flow path is not communicated with the compressor inlet, and a state in which the other end of the bypass flow path is communicated with the compressor inlet. Alternatively, it is provided with a plurality of bypass switching valves, and the heat exchanger switching valve allows the flow of a heat medium between the underground heat exchanger and the outdoor heat exchanger, while the underground heat. It is possible to further switch to a flow path connection state that does not allow the flow of heat medium between the heat exchanger and the outdoor heat exchanger and the indoor heat exchanger, and one end of the bypass flow path is underground. A state in which the heat medium can flow from the outdoor heat exchanger to the bypass flow path via the underground heat exchanger by communicating with the heat heat exchanger, and one end of the bypass flow path becomes the underground heat exchanger. It is possible to switch between the non-communication state and the non-communication state separately.

As described above, in the present invention, the bypass flow path connecting the underground heat exchanger and the compressor inlet side is provided, and the heat medium passes through the bypass flow path without passing through the indoor heat exchanger, and the compressor and the outdoor side. By creating a state in which the heat exchanger and the underground heat exchanger circulate, the temperature of the outdoor heat exchanger drops due to heat absorption during heating, resulting in frost formation around the heat exchanger. In some cases, the underground heat taken into the heat medium by the underground heat exchanger is introduced into the outdoor heat exchanger via a compressor, and the heat is released to the outside by the outdoor heat exchanger to defrost. It is possible to efficiently perform defrosting without affecting the indoor heat exchanger using the heat in the ground, and the deterioration of heat exchange performance due to frost formation can be minimized and defrosting is possible. Therefore, it is not necessary to generate heat separately, and energy consumption related to defrosting can be suppressed.

Further, in the heat pump system according to the present invention, if necessary, the bypass switching valve allows the other end of the bypass flow path to communicate with only one heat medium inflow port of the outdoor heat exchanger. , Furthermore, it is possible to switch.

As described above, in the present invention, the heat medium is the indoor heat exchanger or the compressor in a state where the bypass flow path connects the underground heat exchanger and the heat medium inflow port close to the compressor of the outdoor heat exchanger. By creating a state in which the outdoor heat exchanger and the underground heat exchanger circulate through the bypass flow path without passing through, the temperature drops due to heat absorption in the outdoor heat exchanger during heating. When frost is formed around the heat exchanger, the heat medium in which the underground heat is taken in by the underground heat exchanger is brought to the outdoor heat exchanger and heated by the outdoor heat exchanger. Defrosting is possible by releasing the heat of the medium to the outside, and it is possible to efficiently perform defrosting without affecting the indoor heat exchanger using the heat in the ground, and the heat exchange performance by frost formation. Defrosting can be performed with the minimum necessary energy consumption, and the efficiency of the entire system can be improved, as the deterioration can be minimized and there is no need to generate heat or drive a compressor separately for defrosting. ..

Further, in the heat pump system according to the present invention, if necessary, the underground heat exchanger is used for switching the heat exchanger to an outdoor portion in the heat medium flow path between the expander and the indoor heat exchanger. It is possible to switch between a state in which the inflator and the indoor heat exchanger are communicated with each other via a valve, a state in which only the inflator is communicated, and a state in which the inflator and the indoor heat exchanger are not communicated with each other. The bypass flow path is connected, and the bypass flow path is formed in an outdoor portion in the heat medium flow path between the expander and the indoor heat exchanger and in the heat medium flow path between the indoor heat exchanger and the flow path switching valve. A state in which one end of the bypass flow path does not communicate with the expander and the indoor heat exchanger but communicates only with the underground heat exchanger, which is arranged between the outdoor part and the heat exchanger switching valve. It is possible to switch between a state in which one end of the bypass flow path does not communicate with any of the expander, the indoor heat exchanger and the underground heat exchanger, and the bypass switching valve has a chamber at the other end of the bypass flow path. It is possible to switch between a state where it does not communicate with the inner heat exchanger and only communicates with the switching valve, and a state where the other end of the bypass flow path does not communicate with either the indoor heat exchanger or the switching valve. is there.

As described above, in the present invention, the heat between the indoor heat exchanger arranged indoors and the outdoor heat exchanger, compressor, expansion valve, and flow path switching valve arranged outdoors. By connecting a geothermal heat exchanger or bypass flow path to a location that appears outdoors in the medium flow path via each switching valve so that the communication state can be switched, the indoor unit part of the system and the outdoor unit can be connected. A heat medium circuit for using a geothermal heat exchanger is reasonably and appropriately incorporated between the machine parts, and the heat medium can be circulated through the geothermal heat exchanger so that the geothermal heat can be used as a heat source. , It can be obtained without changing the configuration of the existing indoor unit part and outdoor unit part, and the component part that can use geothermal heat can be installed at low cost, making it easier to install a system that uses geothermal heat. Can be introduced.

Further, in the heat pump system according to the present invention, if necessary, the bypass switching valve has the other end of the bypass flow path in the heat medium flow path between the flow path switching valve and the outdoor heat exchanger. On the other hand, the heat exchanger switching valve is connected to the outdoor heat exchanger side so as to communicate with the flow path switching valve side so as not to communicate with the outdoor heat exchanger side. Allows the flow of heat medium between the heat exchanger and the indoor heat exchanger, while allowing the heat medium to flow between the underground heat exchanger and the indoor heat exchanger and the outdoor heat exchanger. Distribution is not allowed, and one end of the bypass flow path is communicated with the underground heat exchanger, and the heat medium flows between the indoor heat exchanger and the bypass flow path through the underground heat exchanger. It is possible to further switch to the possible flow path connection state.

As described above, in the present invention, a bypass flow path connecting the geothermal heat exchanger and the flow path switching valve is provided, and if necessary, the heat medium passes through the bypass flow path without passing through the outdoor heat exchanger. By creating a state in which the geothermal heat exchanger, the indoor heat exchanger, and the compressor circulate, the geothermal heat exchanger operates as an evaporator during cooling. Is a condenser, the outside air temperature is extremely high, and even in situations where it is difficult to dissipate heat with an outdoor heat exchanger that uses air heat, the heat of the heat medium is released to the ground, which is generally lower than the outside air temperature. In addition to being able to cool and condense the heat medium, the geothermal heat exchanger acts as an evaporator during heating, where the indoor heat exchanger acts as a condenser, and the outside air temperature is extremely low, making the room use air heat. Even in situations where it is difficult for the outside heat exchanger to absorb heat, the heat medium can be heated and evaporated by taking in geothermal heat, which is generally higher than the outside air temperature, and the indoor heat exchanger uses the geothermal heat. Sufficient heat absorption performance and heat dissipation performance can be ensured.

Further, in the heat pump system according to the present invention, a plurality of the indoor heat exchangers are arranged as necessary, and one of the indoor heat exchangers, the outdoor heat exchangers, and the underground heat exchangers. An inflator is connected to each of the heat medium inflow and outflow ports, and each inflator is connected to a common heat medium flow path so that each of the heat exchangers communicates with each other through the inflator. A cooling / heating switching valve is provided to enable switching between a state in which the other heat medium inflow outlet of the inner heat exchanger is communicated with and a state in which the other heat medium inflow outlet is communicated with the inlet side and the outlet side of the compressor, respectively, and heat exchange is provided on the indoor side. At least it is possible to switch between the cooling connection state in which the heat medium leaving the container faces the compressor and the heating connection state in which the heat medium leaving the compressor faces the indoor heat exchanger. The flow path switching valve makes it possible to switch between a state in which the other heat medium inflow outlet in the outdoor heat exchanger is communicated with and a state in which the other heat medium inflow outlet is communicated with the inlet side and the outlet side of the compressor, respectively. , The first flow path connection state, the second flow path connection state, and the third flow path connection in which the outdoor heat exchanger is not communicated with the compressor and the heat medium does not flow to the outdoor heat exchanger. The state can be switched, and the heat exchanger switching valve does not communicate with the state in which the other heat medium inflow outlet in the underground heat exchanger communicates with the inlet side and the outlet side of the compressor, respectively. It is assumed that the state can be switched between the fourth flow path connection state in which the heat medium leaving the compressor goes to the underground heat exchanger and the heat medium leaving the underground heat exchanger is the compressor. It is possible to switch between the fifth flow path connection state toward the ground and the sixth flow path connection state in which the underground heat exchanger is not communicated with the compressor and the heat medium does not flow to the underground heat exchanger. It is a thing.

As described above, in the present invention, when a plurality of indoor heat exchangers are used for heat exchange related to cooling and heating, each switching valve is used in each indoor heat exchanger and compressor. On the other hand, only the outdoor heat exchanger is communicated and only air heat is used as the heat source, and the outdoor heat exchanger and the underground heat exchanger are communicated with each other and air heat and underground heat are used as heat sources. By switching between the state and the state where only the underground heat exchanger is communicated and only the underground heat is used as the heat source, the room can be comfortably operated even in the case of a so-called multi-air conditioner configuration in which multiple indoor heat exchangers are used. A refrigeration cycle or heat pump cycle can be constructed using one or both of the outer heat exchanger and the underground heat exchanger to obtain a state in which cooling and heating can be performed efficiently. Further, by adjusting the flow path connection by each switching valve, it is possible to create a state in which the heat medium circulates in the compressor, the outdoor heat exchanger, and the geothermal heat exchanger without passing through the indoor heat exchanger. When the outdoor heat exchanger reaches a frosted state around the heat exchanger, the geothermal heat taken into the heat medium by the geothermal heat exchanger should be introduced only to the outdoor heat exchanger. It becomes possible to carry out defrosting, and it is possible to efficiently perform defrosting using geothermal heat and avoid deterioration of heat exchange performance.

Further, in the heat pump system according to the present invention, if necessary, an expander connected to one of the heat medium inflow ports of the geothermal heat exchanger appears at a predetermined location outdoors in the common heat medium flow path. The heat exchanger switching valve is connected to the other heat medium inflow port in the geothermal heat exchanger, and is connected to the outside in each heat medium flow path leading to the inlet side and the outlet side of the compressor. It is connected to each of the predetermined locations that appear.

As described above, in the present invention, in the heat pump system in which a plurality of indoor heat exchangers are arranged indoors, the geothermal heat exchanger provides a heat exchanger switching valve to the heat medium flow path appearing outdoors. By being connected so that the communication state can be switched via the system, a heat medium circuit for using the geothermal heat exchanger can be reasonably and appropriately incorporated in the outdoor part of the system, and the heat medium can be incorporated into the geothermal heat exchanger. It is possible to obtain a state in which geothermal heat can be used as a heat source by distributing the above without changing the configuration of each of the existing indoor and outdoor devices that make up the system, and the components that enable geothermal heat can be used at low cost. It can be installed at, and a system that uses geothermal heat can be introduced more easily.

It is explanatory drawing of the air heat utilization cooling state of the heat pump system which concerns on 1st Embodiment of this invention. It is explanatory drawing of the cooling state using air heat and geothermal heat of the heat pump system which concerns on 1st Embodiment of this invention. It is explanatory drawing of the cooling state using geothermal heat of the heat pump system which concerns on 1st Embodiment of this invention. It is explanatory drawing of the heating state using air heat of the heat pump system which concerns on 1st Embodiment of this invention. It is explanatory drawing of the heating state using air heat and geothermal heat of the heat pump system which concerns on 1st Embodiment of this invention. It is explanatory drawing of the heating state using geothermal heat of the heat pump system which concerns on 1st Embodiment of this invention. It is 1st defrost state explanatory view of the outdoor heat exchanger in the heat pump system which concerns on 1st Embodiment of this invention. It is a 2nd defrost state explanatory view of the outdoor heat exchanger in the heat pump system which concerns on 1st Embodiment of this invention. It is explanatory drawing of the air heat utilization cooling state of the heat pump system which concerns on 2nd Embodiment of this invention. It is explanatory drawing of the cooling state using air heat and geothermal heat of the heat pump system which concerns on 2nd Embodiment of this invention. It is explanatory drawing of the heating state using air heat of the heat pump system which concerns on 2nd Embodiment of this invention. It is a schematic system diagram of. It is explanatory drawing of the heating state using air heat and geothermal heat of the heat pump system which concerns on 2nd Embodiment of this invention. It is explanatory drawing of the defrost state of the outdoor heat exchanger in the heat pump system which concerns on 2nd Embodiment of this invention. It is explanatory drawing of the underground temperature recovery state by the heat pump system which concerns on 2nd Embodiment of this invention. It is explanatory drawing of the air-heat utilization air-conditioning state of the heat pump system which concerns on 3rd Embodiment of this invention. It is explanatory drawing of the air-conditioning state using air heat and geothermal heat of the heat pump system which concerns on 3rd Embodiment of this invention. It is explanatory drawing of the defrost state of the outdoor heat exchanger in the heat pump system which concerns on 3rd Embodiment of this invention. It is explanatory drawing of the underground temperature recovery state by the heat pump system which concerns on 3rd Embodiment of this invention.

(First Embodiment of the present invention)
Hereinafter, the first embodiment of the present invention will be described with reference to FIGS. 1 to 8. In this embodiment, an example in which a heat pump is applied to an air conditioner (air conditioner) having an indoor unit and an outdoor unit will be described.

In each of the above figures, the heat pump system 1 according to the present embodiment has an indoor heat exchanger 11 that exchanges heat with the indoor air, an outdoor heat exchanger 12 that exchanges heat with the outdoor air, and a gas phase. The compressor 13 that compresses the heat medium of the above to increase the temperature and pressure of the heat medium, the expansion valve 14 as the expander that expands the heat medium of the liquid phase to reduce the pressure, the indoor heat exchanger 11 and A flow path switching valve 15 for changing the flow path connection relationship between the outdoor heat exchanger 12 and the compressor 13, and a predetermined heat exchange medium and heat medium arranged outside the room for absorbing and radiating heat from the ground. The underground heat exchanger 16 for heat exchange and a plurality of heat exchanger switching valves 61, 62, 63, 64 that can switch between the flow and non-distribution of the heat medium to the underground heat exchanger 16. A bypass flow path 17 having one end connectable to the underground heat exchanger 16 and the other end connectable to the compressor 13, the other end of the bypass flow path 17, the compressor 13 and the outdoor side. The configuration includes a plurality of bypass switching valves 71, 72, 73, 74, 75 that can switch the flow path connection relationship with the heat exchanger 12.

The indoor heat exchanger 11 has a flow path through which a phase-changeable heat medium (refrigerant) such as HFC or HFO flows, and air to be heat exchanged is outside the flow path of the heat medium. It is a known heat exchanger having a structure that circulates and exchanges heat between a heat medium and air through a flow path wall. Specifically, the indoor heat exchanger 11 is arranged in the indoor unit housing of the air conditioner, and the indoor air that can be circulated around the heat exchanger and the heat that circulates inside the heat exchanger. The heat is exchanged with the medium.

In the indoor heat exchanger 11, one heat medium inflow port is connected to a flow path switching valve 15 via a predetermined heat medium flow path, for example, a pipeline, and the other heat medium inflow port is connected to a predetermined heat. It is arranged so as to be connected to the expansion valve 14 via the medium flow path.

The indoor heat exchanger 11 serves as an evaporator for the heat medium when cooling the room, and acts as a condenser for the heat medium when heating the room. Specifically, in the case of a cooling used as an evaporator, in the indoor heat exchanger 11, the heat medium of the liquid phase expanded through the expansion valve 14 flows into the other heat medium inflow port communicating with the expansion valve 14. To do. The indoor heat exchanger 11 exchanges heat between a low pressure and liquid phase heat medium and indoor air at a relatively high predetermined temperature that evaporates the heat medium in this state to generate saturated vapor, and indoors the room. While the heat medium is evaporated by the heat from the air to form a vapor phase, the temperature of the indoor air is lowered by the amount of heat used for the heat medium evaporation. Then, the heat medium of the gas phase evaporated by heat exchange flows out from one of the heat medium inflow outlets communicating with the flow path switching valve 15, and the heat medium flows into the compressor 13 via the flow path switching valve 15. It will be.

Further, in the case of heating used as a condenser, in the indoor heat exchanger 11, one of the heat medium inflow outlets communicates with the outlet side of the compressor 13 via the flow path switching valve 15. The heat medium of the gas phase compressed by the compressor 13 and having a high temperature and high pressure is made to flow into one of the heat medium inflow outlets. Then, in the indoor heat exchanger 11, the heat medium of the gas phase and the indoor air having a relatively low predetermined temperature at which the heat medium is condensed to generate a saturated liquid are exchanged with each other, and the indoor air is transferred from the heat medium. While the heat is transferred to the heat medium to condense the heat medium into a liquid phase, the temperature of the indoor air is raised by the amount of heat released when the heat medium is condensed. Then, the heat medium of the liquid phase condensed by heat exchange flows out from the other heat medium inflow port communicating with the expansion valve 14, and the heat medium reaches the expansion valve 14.

Like the indoor heat exchanger 11, the outdoor heat exchanger 12 has a flow path through which the heat medium flows, and the air to be heat exchanged flows outside the flow path of the heat medium and flows. It is a known heat exchanger having a structure in which heat exchange is performed between a heat medium and air via a road wall. Specifically, the outdoor heat exchanger 12 is arranged in the outdoor unit housing of the air conditioner, and the outdoor air that can be circulated around the heat exchanger and the heat that circulates inside the heat exchanger. The heat is exchanged with the medium.

In the outdoor heat exchanger 12, one heat medium inflow port is connected to the bypass switching valve 74 via a predetermined heat medium flow path, for example, a pipeline, and the other heat medium inflow port is connected to a predetermined heat medium. It is arranged so as to be connected to the heat exchanger switching valves 62 and 63 via a flow path. One of the heat medium inflow outlets of the outdoor heat exchanger 12 can communicate with the flow path switching valve 15 via the bypass switching valves 74 and 73, and the other heat medium inflow outlet is the heat exchanger. It is possible to communicate with the expansion valve 14 via the switching valves 62 and 61.

The outdoor heat exchanger 12 serves as an evaporator for the heat medium when heating the room, and acts as a condenser for the heat medium when cooling the room. Specifically, in the case of heating used as an evaporator, in the outdoor heat exchanger 12, the heat medium of the liquid phase expanded through the expansion valve 14 flows into the other heat medium inflow port communicating with the expansion valve 14. .. Then, in the outdoor heat exchanger 12, heat exchange is performed between the heat medium having a liquid phase at a low pressure and the outdoor air having a relatively high predetermined temperature capable of evaporating the heat medium in this state to generate saturated vapor. While the heat medium is evaporated by the heat from the outdoor air to form a vapor phase, the temperature of the outdoor air is lowered by the amount of heat used for the heat medium evaporation. Then, the heat medium of the gas phase evaporated by heat exchange flows out from one of the heat medium inflow outlets communicating with the flow path switching valve 15, and the heat medium flows into the compressor 13 via the flow path switching valve 15. It will be.

Further, in the case of cooling used as a condenser, in the outdoor heat exchanger 12, one of the heat medium inflow outlets communicates with the outlet side of the compressor 13 via the flow path switching valve 15. The heat medium of the gas phase compressed by the compressor 13 and having a high temperature and high pressure is made to flow into one of the heat medium inflow outlets. Then, in the indoor heat exchanger 11, the heat medium of the gas phase and the outdoor air having a relatively low predetermined temperature, which can condense the heat medium in this state to generate a saturated liquid, are heat-exchanged from the heat medium. The heat is transferred to the outdoor air to condense the heat medium to form a liquid phase, while the temperature of the outdoor air is raised by the amount of heat released when the heat medium is condensed. Then, the heat medium of the liquid phase condensed by heat exchange flows out from the other heat medium inflow port communicating with the expansion valve 14, and the heat medium reaches the expansion valve 14.

Since the outdoor air to be heat exchanged is present in an extremely large amount with respect to the heat medium flowing through the internal flow path in the outdoor heat exchanger 12, the air after the heat exchange is introduced into the outside air. The effect of the heat held by the air after heat exchange on the entire air after diffusion, that is, the temperature change of the entire air after diffusion is almost negligible, and as the heat exchange continues, the outdoor heat exchanger 12 is newly added in sequence. There is no temperature change in the introduced outdoor air, and it can be considered that heat exchange can be continued under the same temperature conditions as when heat exchange started.

The compressor 13 is a known device used in a refrigeration cycle or a heat pump cycle that compresses a heat medium in a gas phase to increase its temperature and pressure, and detailed description thereof will be omitted. In the compressor 13, both the inlet and outlet of the heat medium are connected to the flow path switching valve 15, the inlet is communicated with the indoor heat exchanger 11, and the outlet is communicated with the outdoor heat exchanger 12. The structure is such that the inlet can be communicated with the outdoor heat exchanger 12 and the outlet can be communicated with the indoor heat exchanger 11.

The expansion valve 14 is a known device used in a refrigeration cycle or a heat pump cycle that expands a heat medium of a liquid phase to reduce the pressure thereof, and detailed description thereof will be omitted. In the expansion valve 14, one valve opening is connected to the other heat medium inflow port of the indoor heat exchanger 11 via a predetermined heat medium flow path, and the other valve opening is connected to the other heat medium flow path via a predetermined heat medium flow path. It is arranged so as to be connected to the heat exchanger switching valve 61.

The flow path switching valve 15 switches the combination in which the four connected heat medium flow paths a, b, c, and d communicate with each other, and uses the indoor heat exchanger 11 as an evaporator and the outdoor heat exchanger. Known household air that can switch between a cooling state in which 12 is used as a condenser and a heating state in which the indoor heat exchanger 11 is used as a condenser and the outdoor heat exchanger 12 is used as an evaporator. It is a four-way valve used in a harmonizer (air conditioner), and detailed description of the valve mechanism is omitted.

In the flow path switching valve 15, one of the heat medium inflow outlets of the outdoor heat exchanger 12 is used as the compressor 13 outlet by changing the heat medium flow path connection relationship between the outdoor heat exchanger 12 and the compressor 13. The first flow path connection state in which the heat medium exiting the compressor 13 is directed toward the outdoor heat exchanger 12 and the one heat medium inflow outlet of the outdoor heat exchanger 12 are connected to the compressor 13 inlet. It is possible to switch between the second flow path connection state in which the heat medium exiting the outdoor heat exchanger 12 is directed toward the compressor 13 by communicating with the compressor 13.

At the same time, the flow path switching valve 15 also changes the heat medium flow path connection relationship between the indoor heat exchanger 11 and the compressor 13, and in the first flow path connection state, the indoor heat exchanger 11 One of the heat medium inflow outlets is communicated with the compressor 13 inlet so that the heat medium exiting the indoor heat exchanger 11 faces the compressor 13, and in the second flow path connection state, the indoor heat is generated. One of the heat medium inflow outlets of the exchanger 11 is communicated with the compressor 13 outlet so that the heat medium exiting the compressor 13 faces the indoor heat exchanger 11.
Although the flow path switching valve 15 is used as one valve, it may be configured by combining a plurality of valves.

The geothermal heat exchanger 16 circulates a heat medium and a heat exchange medium for geothermal heat, which is a heat exchange target thereof, in a predetermined flow path separated by a heat transfer surface. A known heat exchanger that exchanges heat between a heat medium and a heat exchange medium via a heat transfer surface, for example, a plate heat exchanger, etc., and a detailed description of the mechanism of the heat exchanger. Is omitted.

The geothermal heat exchanger 16 is arranged outdoors so as to be intervenable between the outdoor heat exchanger 12 and the expansion valve 14 in the heat pump cycle, and is located in the geothermal heat exchanger 50 buried in the ground. The heat exchange is such that the heat medium is exchanged with a predetermined heat exchange medium, for example, water, which is returned to the ground side after being set to a predetermined temperature according to the temperature in the ground by heat exchange.

The geothermal heat exchanger 16 is connected to the heat medium flow path between the expansion valve 14 and the outdoor heat exchanger 12 via the heat exchanger switching valves 61, 62, 63, 64. In these plurality of valves, the heat medium side flow path of the geothermal heat exchanger 16 is enabled to flow the heat medium and is interposed between the expansion valve 14 and the outdoor heat exchanger 12. It is a mechanism that enables switching between a state in which the geothermal heat exchanger 16 does not intervene at all.

In a state where the heat medium is circulated through the underground heat exchanger 16 and the heat medium is exchanged with the heat exchange medium, when the flow path switching valve 15 is in the first flow path connection state, the geothermal heat is generated. The heat exchanger 16 functions as a condenser as in the case of the outdoor heat exchanger 12, and performs heat exchange that condenses the heat medium or lowers the temperature of the heat medium. Further, when the flow path switching valve 15 is in the second flow path connection state, the geothermal heat exchanger 16 functions as an evaporator as in the case of the outdoor heat exchanger 12, and the heat medium is used. Heat exchange is performed to evaporate or raise the temperature of the heat medium.

The heat exchanger switching valves 61, 62, 63, 64 are between the outdoor heat exchanger 12 and the geothermal heat exchanger 16 and between the geothermal heat exchanger 16 and the expansion valve 14. A state in which the geothermal heat exchanger 16 intervenes between the outdoor heat exchanger 12 and the expansion valve 14 so that the heat medium can flow, and the outdoor heat exchanger 12 are arranged in the heat medium flow paths of the above. And the expansion valve 14 are directly connected to each other so that the geothermal heat exchanger 16 is not interposed in the middle, and the state in which the heat medium is not circulated through the geothermal heat exchanger 16 can be switched.

Specifically, the first switching between the flow state and the flow stop state of the heat medium between the heat medium flow path connected to one heat medium inflow port of the underground heat exchanger 16 and the expansion valve 14. Heat exchanger switching valve 61, and the heat medium flow state between the heat medium flow path e connected to one heat medium inflow port of the underground heat exchanger 16 and the outdoor heat exchanger 12. A second heat exchanger switching valve 62 that switches between the state and the flow stop state, a heat medium flow path f connected to the other heat medium inflow port of the underground heat exchanger 16, and an outdoor heat exchanger 12. A heat medium flow path connected to a third heat exchanger switching valve 63 for switching between a heat medium flow state and a flow stop state between the two, and one heat medium inflow port of the underground heat exchanger 16. e, or the heat medium flow path f connected to the other heat medium inflow port of the underground heat exchanger 16, and the flow state and flow stop state of the heat medium in the underground heat exchanger 16. It is configured to include a fourth heat exchanger switching valve 64 for switching between the two.

In these heat exchanger switching valves 61, 62, 63, 64, the first heat exchanger switching valve 61 is opened, the second heat exchanger switching valve 62 is closed, and the third heat exchanger is closed. By opening the switching valve 63 and opening the fourth heat exchanger switching valve 64, the outdoor heat exchanger 12 to the third heat exchanger switching valve 63 and the fourth heat exchanger switching are switched. A heat medium can flow through the valve 64, the underground heat exchanger 16, the first heat exchanger switching valve 61, and the expansion valve 14, and the outdoor heat exchanger 12 and the expansion valve 14 The underground heat exchanger 16 can be placed between them so that the heat medium can flow (see FIGS. 2 and 5).

Further, the first heat exchanger switching valve 61 is opened, the second heat exchanger switching valve 62 is opened, the third heat exchanger switching valve 63 is closed, and the fourth heat exchanger is closed. By closing the switching valve 64, heat is transferred from the outdoor heat exchanger 12 to the expansion valve 14 via the second heat exchanger switching valve 62 and the first heat exchanger switching valve 61. A state in which the medium can be circulated, the outdoor heat exchanger 12 and the expansion valve 14 are directly connected, the underground heat exchanger 16 is not interposed in the middle, and the heat medium is not circulated through the underground heat exchanger 16. (See FIGS. 1 and 4).

In addition, the first heat exchanger switching valve 61 and the third heat exchanger switching valve 63 are closed, respectively, and the second heat exchanger switching valve 62 and the fourth heat exchanger switching valve 64 are closed. By opening each of the above, the outdoor heat exchanger 12 to the second heat exchanger switching valve 62 are opened while stopping the flow of the heat medium between the expansion valve 14 and the underground heat exchanger 16. Through this, the heat medium can be circulated in the path leading to the underground heat exchanger 16, and the heat medium can be circulated between the outdoor heat exchanger 12 and the underground heat exchanger 16, while the expansion valve. It is possible to establish a flow path connection state in which the flow of the heat medium between the underground heat exchanger 16 and the indoor heat exchanger 11 via the 14 is not allowed (see FIG. 7).

On the contrary, the first heat exchanger switching valve 61 and the fourth heat exchanger switching valve 64 are opened, respectively, and the second heat exchanger switching valve 62 and the third heat exchanger switching valve 63 are opened. By closing each of the above, the expansion valve 14 to the first heat exchanger switching valve 61 can be moved from the expansion valve 14 to the first heat exchanger switching valve 61 while stopping the flow of the heat medium between the outdoor heat exchanger 12 and the underground heat exchanger 16. After that, the heat medium can be circulated in the path leading to the underground heat exchanger 16, and the heat medium can be circulated between the indoor heat exchanger 11 and the underground heat exchanger 16 via the expansion valve 14. On the other hand, it is possible to establish a flow path connection state in which the flow of the heat medium between the underground heat exchanger 16 and the outdoor heat exchanger 12 is not permitted (see FIGS. 3 and 6).

One end of the bypass flow path 17 is connected to a heat medium flow path f connected to the other heat medium inflow port of the geothermal heat exchanger 16, and the other end is a bypass switching valve 71, 72, 73. , 74, 75 can be connected to the flow path switching valve 15, the compressor 13, or the outdoor heat exchanger 12, and the heat medium is circulated as needed.

One end of the bypass flow path 17 is connected to the heat medium flow path f provided with the fourth heat exchanger switching valve 64 among the heat exchanger switching valves, so that the fourth heat exchanger switching valve can be used. When the valve 64 is opened, it communicates with the geothermal heat exchanger 16, while when the fourth heat exchanger switching valve 64 is closed, it does not communicate with the geothermal heat exchanger 16. It is a mechanism that allows the communication state to the exchanger 16 to be switched as needed.

Further, after closing the third heat exchanger switching valve 63 with respect to one end of the bypass flow path 17, the second heat exchanger switching valve 62 is provided together with the fourth heat exchanger switching valve 64. By opening the bypass flow path 17, one end of the bypass flow path 17 communicates with the outdoor heat exchanger 12 through the geothermal heat exchanger 16, and the bypass flow path 17 passes through the geothermal heat exchanger 16 to the outdoor side. The heat medium can be circulated in the path leading to the heat exchanger 12. In this case, if the first heat exchanger switching valve 61 is closed, the flow of the heat medium to the expansion valve 14 and the indoor heat exchanger 11 can be blocked, and the heat medium becomes the indoor heat exchanger 11. It is possible to set the state of passing through the bypass flow path 17 instead of passing through (see FIGS. 7 and 8).

In addition, after closing the third heat exchanger switching valve 63 with respect to one end of the bypass flow path 17, the first heat exchanger switching valve 61 together with the fourth heat exchanger switching valve 64 By opening, one end of the bypass flow path 17 is in a state of communicating with the expansion valve 14 and the indoor heat exchanger 11 through the geothermal heat exchanger 16, and the geothermal heat exchanger is communicated from the bypass flow path 17. The heat medium can be circulated through the path 16 and the expansion valve 14 to the indoor heat exchanger 11. Then, in this case, if the second heat exchanger switching valve 62 is closed, the flow of the heat medium to the outdoor heat exchanger 12 can be blocked, and instead of the heat medium passing through the outdoor heat exchanger 12. The state of passing through the bypass flow path 17 can be set (see FIGS. 3 and 6).

The bypass switching valves 71, 72, 73, 74, 75 are the heat medium flow path a connecting the other end of the bypass flow path 17, the flow path switching valve 15 and the inlet of the compressor 13, and the flow path. The connection relationship between the switching valve 15 and the heat medium flow path b that connects one of the heat medium inflow outlets of the outdoor heat exchanger 12 and the like can be switched.

Specifically, as the bypass switching valve, the heat medium between the heat medium flow path a connecting the flow path switching valve 15 and the inlet of the compressor 13 and the other end of the bypass flow path 17 A first bypass switching valve 71 that switches between a flow state and a flow stop state, a heat medium flow path b that connects the flow path switching valve 15 and one heat medium inflow port of the outdoor heat exchanger 12. A second bypass switching valve 72 for switching between a flow state and a flow stop state of the heat medium between the other end of the bypass flow path 17 and the second bypass switching valve 72 in the heat medium flow path b. A third bypass switching valve 73, which is arranged in the flow path portion on the flow path switching valve 15 side from the connection portion of the valve 72 and switches between the flow state and the flow stop state of the heat medium in this flow path portion, In the same heat medium flow path b, it is arranged in the flow path portion on the outdoor heat exchanger 12 side from the connection portion of the second bypass switching valve 72, and the flow state and distribution of the heat medium in this flow path portion. A fourth bypass switching valve 74 for switching between the stopped state and a fifth bypass switching valve 75 arranged in the bypass flow path 17 for switching between the flow state and the flow stop state of the heat medium in the bypass flow path 17. It is a configuration including.

In these bypass switching valves 71, 72, 73, 74, 75, the first bypass switching valve 71 and the second bypass switching valve 72 are all closed, and the third bypass switching valve 73 and the fourth By opening all the bypass switching valves 74 and closing the fifth bypass switching valve 75, the other end of the bypass flow path 17 connects the flow path switching valve 15 and the compressor 13 inlet. The heat medium flow path a is not communicated with any of the heat medium flow path b connecting the flow path switching valve 15 and one of the heat medium inflow outlets of the outdoor heat exchanger 12, and the flow path is switched. The heat medium can flow through the heat medium flow path b from the valve 15, the third bypass switching valve 73, and the fourth bypass switching valve 74 to the outdoor heat exchanger 12, and the bypass flow path 17 is provided. A connection state can be obtained when performing normal cooling or heating that is not used. That is, while the other end of the bypass flow path 17 is not communicated with the inlet of the compressor 13, one of the heat medium inflow outlets of the indoor heat exchanger 11 is communicated with the inlet of the compressor 13 and one of the outdoor heat exchangers 12. The connection state during cooling (see FIGS. 1 and 2) in which the heat medium inflow port is communicated with the compressor 13 outlet, and one of the heat medium inflow outlets in the indoor heat exchanger 11 is communicated with the compressor 13 outlet. In addition, the connection state during heating (see FIGS. 4 and 5) can be set so that one of the heat medium inflow outlets in the outdoor heat exchanger 12 communicates with the compressor 13 inlet.

Further, the first bypass switching valve 71 is opened, the second bypass switching valve 72 is closed, the third bypass switching valve 73 and the fourth bypass switching valve 74 are both opened, and the second bypass switching valve 74 is opened. By opening the bypass switching valve 75 of 5, the other end of the bypass flow path 17 communicates with the heat medium flow path a connecting the flow path switching valve 15 and the inlet of the compressor 13, while the flow path. It does not communicate with the heat medium flow path b that connects the switching valve 15 and one of the heat medium inflow outlets of the outdoor heat exchanger 12, and in addition, the flow path switching valve 15 to the third bypass switching valve The heat medium can flow through the heat medium flow path b leading to the outdoor heat exchanger 12 via the 73 and the fourth bypass switching valve 74, and the other end of the bypass flow path 17 is communicated with the inlet of the compressor 13. , A state is obtained in which the heat medium can be circulated from the bypass flow path 17 toward the compressor 13 (see FIG. 7).

In this state, the first heat exchanger switching valve 61 is closed, the second heat exchanger switching valve 62 is opened, and the third heat exchanger switching valve 62 is opened on one end side of the bypass flow path 17. By closing 63 and opening the fourth heat exchanger switching valve 64, the bypass flow path 17 communicates with the outdoor heat exchanger 12 through the underground heat exchanger 16 and is connected to the outdoor heat exchanger 12. While the heat medium can flow from 12 to the underground heat exchanger 16 to the bypass flow path 17, the heat medium does not flow to the indoor heat exchanger 11, and the heat medium becomes the indoor heat exchanger 11. Instead of passing through the above, it passes through the bypass flow path 17 and reaches the compressor 13.

As a result, the heat medium flows from the compressor 13 through the flow path switching valve 15 in the first flow path connection state into the outdoor heat exchanger 12, and from the outdoor heat exchanger 12 to the geothermal heat exchanger. A state in which the heat medium exiting the geothermal heat exchanger 16 heads toward 16 creates a circulation path that returns to the compressor 13 through the bypass flow path 17, that is, the geothermal heat exchanger 16. The heat medium is heated to a high pressure by the compressor 13, heat is released from the heat medium by the outdoor heat exchanger 12, and defrosting can be performed by the outdoor heat exchanger 12. The first defrosting connection state will be obtained.

Further, the first bypass switching valve 71 is closed, the second bypass switching valve 72 is opened, the third bypass switching valve 73 is closed, and the fourth bypass switching valve 74 is opened. By opening the fifth bypass switching valve 75, the other end of the bypass flow path 17 connects the flow path switching valve 15 and one heat medium inflow port of the outdoor heat exchanger 12. Of the flow path b, the heat that connects the flow path switching valve 15 and the compressor 13 inlet while communicating with the flow path portion on the outdoor heat exchanger 12 side from the connection point of the second bypass switching valve 72. The medium flow path a and the heat medium flow path b do not communicate with the flow path portion on the flow path switching valve 15 side from the connection point of the second bypass switching valve 72, whereby the bypass flow path 17 and others A state is obtained in which the end is communicated with only one heat medium inflow port of the outdoor heat exchanger 12 so that the heat medium can flow from the bypass flow path 17 toward the outdoor heat exchanger 12 (see FIG. 8). ..

In this state, the first heat exchanger switching valve 61 is closed, the second heat exchanger switching valve 62 is opened, and the third heat exchanger switching valve 62 is opened on one end side of the bypass flow path 17. By closing 63 and opening the fourth heat exchanger switching valve 64, one end of the bypass flow path 17 passes through the underground heat exchanger 16 and the other heat medium inflow outlet of the outdoor heat exchanger 12. The heat medium can flow from the outdoor heat exchanger 12 to the bypass flow path 17 via the underground heat exchanger 16, while the heat medium does not flow to the indoor heat exchanger 11. Instead of passing through the indoor heat exchanger 11, the heat medium passes through the bypass flow path 17 and reaches the outdoor heat exchanger 12.

As a result, the heat medium flows into the outdoor heat exchanger 12, goes from the outdoor heat exchanger 12 to the geothermal heat exchanger 16, and the heat medium exiting the geothermal heat exchanger 16 passes through the bypass flow path 17. A state in which a circulation path is generated to return to the outdoor heat exchanger 12 through the outdoor heat exchanger 12, that is, the heat medium is heated by the geothermal heat in the geothermal heat exchanger 16, and the heat medium is passed through the bypass flow path 17 to the chamber. A second defrosting connection state is obtained in which the outdoor heat exchanger 12 is guided to the outdoor heat exchanger 12 and heat is released from the heat medium by the outdoor heat exchanger 12 so that defrosting can be performed by the outdoor heat exchanger 12. Become.

In addition, the first bypass switching valve 71 is closed, the second bypass switching valve 72 and the third bypass switching valve 73 are both opened, and the fourth bypass switching valve 74 is closed. By opening the fifth bypass switching valve 75, the other end of the bypass flow path 17 connects the flow path switching valve 15 and one heat medium inflow port of the outdoor heat exchanger 12. Of the flow path b, the heat that connects the flow path switching valve 15 and the compressor 13 inlet while communicating with the flow path portion on the flow path switching valve 15 side from the connection point of the second bypass switching valve 72. The medium flow path a and the heat medium flow path b do not communicate with the flow path portion on the outdoor heat exchanger 12 side from the connection point of the second bypass switching valve 72, whereby the bypass flow path 17 and others are not communicated. The end is communicated with a part of the heat medium flow path b connecting the flow path switching valve 15 and one heat medium inflow port of the outdoor heat exchanger 12, and the heat medium flow path b is connected from the bypass flow path 17. A state is obtained in which the heat medium can be circulated in the path leading to the compressor 13 via the flow path switching valve 15 and the heat medium flow path a.

In this state, the first heat exchanger switching valve 61 is opened on one end side of the bypass flow path 17, and the second heat exchanger switching valve 62 and the third heat exchanger switching valve 63 are eventually opened. By opening the fourth heat exchanger switching valve 64, the bypass flow path 17 communicates with the indoor heat exchanger 11 through the underground heat exchanger 16 and the indoor heat exchanger 11 The heat medium can flow through the path from the underground heat exchanger 16 to the bypass flow path 17, while the heat medium does not flow through the outdoor heat exchanger 12, and the heat medium exchanges outdoor heat. Instead of passing through the vessel 12, it passes through the bypass flow path 17 and flows to the underground heat exchanger 16.

As a result, a connection state for cooling or heating using the geothermal heat exchanger 16 instead of the outdoor heat exchanger 12 can be obtained. That is, while the outdoor heat exchanger 12 is removed from the refrigeration cycle and the heat pump cycle, one heat medium inflow outlet in the indoor heat exchanger 11 is communicated with the compressor 13 inlet, and the other in the geothermal heat exchanger 16. The connection state during cooling (see FIG. 3) in which the heat medium inflow outlet of the above is communicated with the compressor 13 outlet through the bypass flow path 17, and one of the heat medium inflow outlets in the indoor heat exchanger 11 is communicated with the compressor 13 outlet. The connection state during heating (see FIG. 6) can be set so that the other heat medium inflow outlet in the geothermal heat exchanger 16 is communicated with the compressor 13 inlet through the bypass flow path 17.

Further, the heat pump system according to the present embodiment has a fan for forcibly sending air to each heat exchanger, a temperature sensor for detecting the temperature of indoor air, and air conditioning, similar to those used in known air conditioners. An operation unit operated by the user who uses the machine, a control unit that controls the operation of the compressor and fan based on the operation content of the user and the detection results of various sensors, and the cooling / heating switching control by the flow path switching valve. The configuration is provided, and detailed description thereof will be omitted.

However, in the present embodiment, in particular, in addition to the temperature of the indoor air, the temperature of the outdoor air, the temperature in the ground, the temperature of the heat medium at one or more points in the cycle, the heat exchange for heat absorption or heat dissipation to the ground. Each temperature sensor for detecting the temperature of the medium is provided, and a frost sensor for detecting the frosted state on the outdoor heat exchanger is provided, and the control unit detects the detection result with each of these temperature sensors and the frost sensor. Based on the above, in addition to the operation control of each part, the control of the pump that circulates the heat exchange medium between the geothermal heat exchanger and the underground heat exchange part and the opening / closing control of each switching valve are performed as needed. Will be executed.

Next, the operating state of the heat pump system according to the present embodiment will be described.
First, a state in which the heat pump system is operated to cool the indoor space will be described.
When cooling, it is possible to switch the state where the heat source is only outdoor air heat, only underground heat, or both air heat and underground heat, depending on the indoor, outdoor, underground conditions, etc. it can. For example, since the underground temperature is usually lower than the outdoor air temperature during the cooling period, if the outdoor air temperature is excessively high and the cooling efficiency is low, only the geothermal heat should be used as the heat source. , Efficient cooling can be performed.

Further, since the load on the indoor unit side of the air conditioner becomes large at the start of the cooling operation, it is preferable to use both outdoor air heat and geothermal heat as the heat source. Then, when the room temperature reaches a desired temperature and shifts to a stable state, and the air conditioner becomes a low-load operation state in which on / off repetition and output are suppressed, only geothermal heat is used as a heat source. If the switching is performed, an efficient operating state can be maintained, which is preferable.

In addition, when the temperature of the heat medium is lower than the outdoor air temperature, the cooling operation is performed with the outdoor air heat and the geothermal heat mainly used as heat sources, while the heat medium temperature is close to the outdoor air temperature. If it is expected that an excessive heat load is applied to the ground, such as when the temperature in the ground rises excessively, the system shifts to an operating state in which the heat source is only outdoor air heat, and the geothermal heat is generated. It is preferable to stop the release of heat into the ground through the exchanger 16 and the heat exchange medium so that the ground temperature can be recovered.

(When the heat source is only air heat)
When cooling the indoor space, when only outdoor air heat is used as the heat source, that is, when only the outdoor heat exchanger 12 is used as the outdoor condenser, heat is used as shown in FIG. The valves 61 and 62 of the exchanger switching valve are opened so that the outdoor heat exchanger 12 communicates with the expansion valve 14 through each valve. The flow path switching valve 15 is in the first flow path connection state, in which the heat medium flow path a and the heat medium flow path d are communicated with each other, and the heat medium flow path b and the heat medium flow path c are communicated with each other.

When the system is operated, the indoor heat exchanger 11 exchanges heat between the indoor air introduced by being blown by a fan (not shown) and the heat medium of the liquid phase as an evaporator. The heat medium that is heated by heat exchange in the indoor heat exchanger 11 and evaporates as the temperature rises to become a gas phase goes out of the indoor heat exchanger 11 and flows through the heat medium flow path d. It goes to the compressor 13 via the path switching valve 15 and the heat medium flow path a. On the other hand, the indoor air is cooled by the heat exchange in the indoor heat exchanger 11 and released into the indoor space in a state where the temperature is lowered, and the indoor temperature is lowered to a desired temperature (cooling the indoor space).

The heat medium of the high temperature gas phase that has left the indoor heat exchanger 11 and reached the compressor 13 is pressurized by the compressor 13 that is operated by an external drive source. The heat medium of the pressurized gas phase is in a state of increasing pressure and temperature. Then, the heat medium of the gas phase leaving the compressor 13 passes through the heat medium flow path c, the flow path switching valve 15, the heat medium flow path b, and the valves 73 and 74 in the open state, and then the outdoor heat exchanger. Introduced in 12.

As a condenser, the outdoor heat exchanger 12 exchanges heat between the outdoor air introduced by being blown by a fan (not shown) and the heat medium of the gas phase. The heat medium of the gas phase cooled by this heat exchange condenses and changes into a liquid phase. On the other hand, the outdoor air, which is the medium to be heated, is heated by the heat exchange in the outdoor heat exchanger 12, and is discharged into the outside air in a state where the temperature is raised.

The liquid phase heat medium obtained by condensing in the outdoor heat exchanger 12 is discharged to the outside of the outdoor heat exchanger 12 and heads for the expansion valve 14, but the heat exchanger in the vicinity of the geothermal heat exchanger 16 Among the switching valves, the valves 61 and 62 are opened and the valves 63 and 64 are closed, so that the heat medium exiting the outdoor heat exchanger 12 passes through the valves 61 and 62 and exchanges geothermal heat. It reaches the expansion valve 14 without circulating to the vessel 16.

The heat medium expands at the expansion valve 14, and after the pressure and temperature are reduced, the heat medium proceeds toward the indoor heat exchanger 11.
After that, the heat medium returns to the inside of the indoor side heat exchanger 11, and each process after the heat exchange in the indoor side heat exchanger 11 is repeated in the same manner as described above to continuously execute the cooling.

(When the heat source is air heat and geothermal heat)
When outdoor air heat and geothermal heat are used as heat sources when cooling the indoor space, that is, when both the outdoor heat exchanger 12 and the geothermal heat exchanger 16 are used as the outdoor condenser. As shown in FIG. 2, the valves 64 and 61 of the heat exchanger switching valves are opened, and the outdoor heat exchanger 12 is switched to a state in which the outdoor heat exchanger 12 communicates with the expansion valve 14 through the geothermal heat exchanger 16.

When the system is operated, the indoor heat exchanger 11 exchanges heat between the indoor air introduced by being blown by a fan (not shown) and the heat medium of the liquid phase as an evaporator. The heat medium that is heated by heat exchange in the indoor heat exchanger 11 and evaporates as the temperature rises to become a gas phase goes out of the indoor heat exchanger 11 and flows through the heat medium flow path d. It goes to the compressor 13 via the path switching valve 15 and the heat medium flow path a. On the other hand, the indoor air is cooled by the heat exchange in the indoor heat exchanger 11 and released into the indoor space in a state where the temperature is lowered, and the indoor temperature is lowered to a desired temperature (cooling the indoor space).

The heat medium of the high temperature gas phase that has left the indoor heat exchanger 11 and reached the compressor 13 is pressurized by the compressor 13 that is operated by an external drive source. The heat medium of the pressurized gas phase is in a state of increasing pressure and temperature. Then, the heat medium of the gas phase leaving the compressor 13 passes through the heat medium flow path c, the flow path switching valve 15, the heat medium flow path b, and the valves 73 and 74 in the open state, and then the outdoor heat exchanger. Introduced in 12.

The outdoor heat exchanger 12 exchanges heat between the outdoor air, which is a medium to be heated and introduced by being blown by a fan (not shown), and the heat medium of the gas phase as a condenser. The heat medium of the gas phase cooled by this heat exchange lowers its temperature, and a part of it condenses and changes into a liquid phase. On the other hand, the outdoor air, which is the medium to be heated, is heated by the heat exchange in the outdoor heat exchanger 12, and is discharged into the outside air in a state where the temperature is raised.

The heat medium whose temperature has been lowered by the outdoor heat exchanger 12 is discharged to the outside of the outdoor heat exchanger 12, but among the heat exchanger switching valves near the geothermal heat exchanger 16, the valve 61, When 63 and 64 are opened and the valve 62 is closed, the heat medium exiting the outdoor heat exchanger 12 passes through the valve 63, the heat medium flow path f and the valve 64 to the geothermal heat exchanger 16. It will be distributed.

In the geothermal heat exchanger 16, the heat exchange medium introduced by being pressurized by a pump (not shown) exchanges heat with the heat medium, and the heat medium of the gas phase cooled by this heat exchange is used. It will condense and change to a liquid phase. On the other hand, the heat exchange medium is heated by the heat exchange in the geothermal heat exchanger 16 and heads for the geothermal heat exchange unit 50 in a state where the temperature is raised. Then, the heat exchange medium releases heat into the ground by the geothermal heat exchange unit 50 to lower the temperature, and then returns to the geothermal heat exchanger 16 again. The circulation of the heat exchange medium between the geothermal heat exchanger 16 and the geothermal heat exchanger 50 will be repeated as long as the heat exchange in the geothermal heat exchanger 16 is continued.

The liquid phase heat medium obtained by condensing in the geothermal heat exchanger 16 exits the geothermal heat exchanger 16 and then passes through the heat medium flow path e and the valve 61 to reach the expansion valve 14. .. The heat medium expands at the expansion valve 14, and after the pressure and temperature are reduced, the heat medium proceeds toward the indoor heat exchanger 11.
After that, the heat medium returns to the inside of the indoor side heat exchanger 11, and each process after the heat exchange in the indoor side heat exchanger 11 is repeated in the same manner as described above to continuously execute the cooling.

(When the heat source is only geothermal heat)
When only geothermal heat is used as the heat source when cooling the indoor space, that is, when only the geothermal heat exchanger 16 is used as the outdoor condenser, as shown in FIG. 3, in advance. A state in which the valves 72 and 75 of the bypass switching valve are opened, the valves 74 are closed, the heat medium flow path b communicates with the bypass flow path 17, and the heat medium exiting the compressor 13 flows to the bypass flow path 17. At the same time, the valves 64 and 61 of the heat exchanger switching valve are opened to switch to a state in which the bypass flow path 17 communicates with the expansion valve 14 through the geothermal heat exchanger 16.

Similarly to the above, the indoor heat exchanger 11 exchanges heat between the indoor air introduced by being blown by a fan (not shown) and the heat medium of the liquid phase as an evaporator. The heat medium that is heated by heat exchange in the indoor heat exchanger 11 and evaporates as the temperature rises to become a gas phase goes out of the indoor heat exchanger 11 and flows through the heat medium flow path d. It goes to the compressor 13 via the path switching valve 15 and the heat medium flow path a. On the other hand, the indoor air is cooled by the heat exchange in the indoor heat exchanger 11 and released into the indoor space in a state where the temperature is lowered, and the indoor temperature is lowered to a desired temperature (cooling the indoor space).

The heat medium of the high temperature gas phase that has left the indoor heat exchanger 11 and reached the compressor 13 is pressurized by the compressor 13 that is operated by an external drive source. The heat medium of the pressurized gas phase is in a state of increasing pressure and temperature. Then, the heat medium of the gas phase leaving the compressor 13 passes through the heat medium flow path c, the flow path switching valve 15, the heat medium flow path b, and the valves 73, 72, and 75 in the open state, and then the bypass flow path. Reach 17

On the other hand, the valve 64 in the heat medium flow path f to which one end of the bypass flow path 17 is connected is opened, and the valve 61 is opened and the valves 62 and 63 are closed in the vicinity of the geothermal heat exchanger 16. Then, the gas phase heat medium that has passed through the bypass flow path 17 passes through the heat medium flow path f and the valve 64 and flows to the geothermal heat exchanger 16.

In the geothermal heat exchanger 16, the heat exchange medium introduced by being pressurized by a pump (not shown) exchanges heat with the heat medium, and the heat medium of the gas phase cooled by this heat exchange is used. It will condense and change to a liquid phase. On the other hand, the heat exchange medium is heated by the heat exchange in the geothermal heat exchanger 16 and heads for the geothermal heat exchange unit 50 in a state where the temperature is raised. Then, the heat exchange medium releases heat into the ground by the geothermal heat exchange unit 50 to lower the temperature, and then returns to the geothermal heat exchanger 16 again. The circulation of the heat exchange medium between the geothermal heat exchanger 16 and the geothermal heat exchanger 50 will be repeated as long as the heat exchange in the geothermal heat exchanger 16 is continued.

The liquid phase heat medium obtained by condensing in the geothermal heat exchanger 16 exits the geothermal heat exchanger 16 and then passes through the heat medium flow path e and the valve 61 to reach the expansion valve 14. .. The heat medium expands at the expansion valve 14, and after the pressure and temperature are reduced, the heat medium proceeds toward the indoor heat exchanger 11.
After that, the heat medium returns to the inside of the indoor side heat exchanger 11, and each process after the heat exchange in the indoor side heat exchanger 11 is repeated in the same manner as described above to continuously execute the cooling.

In addition, in response to the case where geothermal heat is used as the heat source during cooling as described above, heat is taken from the ground and the heat is taken from the ground during times when cooling operation is not required, such as at night or when there are no people in the room. It is also possible to execute the operation as a cycle in which the air is released to the outdoor air, and to actively recover the underground temperature that has risen due to the heat release accompanying the cooling operation and store the cold heat in the ground.

In order to perform the operation for recovering the underground temperature or the like, the valves 75, 71, 73, 74 of the bypass switching valve are opened, the valves 72 are closed, and the bypass flow path 17 becomes the heat medium flow path a. The heat medium that has passed through the bypass flow path 17 is switched to a state in which it flows to the compressor 13, and the valves 62 and 64 of the heat exchanger switching valves are opened, so that the bypass flow path 17 is a geothermal heat exchanger. The state is switched to the state of communicating with the outdoor heat exchanger 12 through 16. Further, the flow path switching valve 15 is in a state where the heat medium flow path a and the heat medium flow path d are communicated with each other and the heat medium flow path b and the heat medium flow path c are communicated with each other as the first flow path connection state. (See FIG. 7).

When the operation is executed, in the underground heat exchanger 16, the heat exchange medium introduced by being pressurized by a pump (not shown) and the heat medium exchange heat, and the liquid heated by this heat exchange. The heat medium of the phase heats up and evaporates to change into a gas phase. On the other hand, the heat exchange medium is cooled by the heat exchange in the geothermal heat exchanger 16 and heads for the geothermal heat exchange unit 50 in a state where the temperature is lowered. Then, the heat exchange medium absorbs heat from the ground by the geothermal heat exchange unit 50 to raise the temperature, and then returns to the geothermal heat exchanger 16 again. The circulation of the heat exchange medium between the geothermal heat exchanger 16 and the geothermal heat exchange unit 50 is repeated for the duration of the operation, and the heat exchange medium absorbs heat from the ground. The temperature in the ground can be lowered.

The gas phase heat medium obtained by evaporating in the geothermal heat exchanger 16 exits the geothermal heat exchanger 16 and then passes through the heat medium flow path f and the valve 64 to the bypass flow path 17. To circulate.
On the other hand, since the other end of the bypass flow path 17 communicates with the heat medium flow path a by the valves 75 and 71 opened, the gas phase heat medium passing through the bypass flow path 17 is the valve 75. , 71 and the heat medium flow path a toward the compressor 13.

The heat medium of the high temperature gas phase that has reached the compressor 13 is pressurized by the compressor 13 to increase the pressure and temperature. Then, the heat medium of the gas phase leaving the compressor 13 passes through the heat medium flow path c, the flow path switching valve 15, the heat medium flow path b, and the valves 73 and 74 in the open state, and then the outdoor heat exchanger. Introduced in 12.

As a condenser, the outdoor heat exchanger 12 exchanges heat between the outdoor air introduced by being blown by a fan (not shown) and the heat medium of the gas phase. The heat medium of the gas phase cooled by this heat exchange lowers its temperature and condenses into a liquid phase. On the other hand, the outdoor air is heated by the heat exchange in the outdoor heat exchanger 12, and is discharged into the outside air in a state where the temperature is raised.

The heat medium condensed by the outdoor heat exchanger 12 is discharged to the outside of the outdoor heat exchanger 12, but the valves 62 and 64 of the heat exchanger switching valves near the geothermal heat exchanger 16 are opened. When the valves 61 and 63 are closed, the heat medium exiting the outdoor heat exchanger 12 passes through the valve 62 and the heat medium flow path e and proceeds toward the geothermal heat exchanger 16. ..

After that, the heat medium returns to the inside of the geothermal heat exchanger 16, and each process after the heat exchange in the geothermal heat exchanger 16 is repeated in the same manner as described above.
When the underground temperature drops to an appropriate temperature or the time zone for cooling the indoor space is reached, the operation related to the recovery of the underground temperature is stopped and the operation is shifted to the cooling operation as necessary. ..

Subsequently, a state in which the heat pump system is operated to heat the indoor space will be described.
When heating, as in the case of cooling, the heat source is only outdoor air heat, only underground heat, or both air heat and underground heat, such as indoor, outdoor, and underground conditions. It can be switched according to. For example, since the underground temperature is usually higher than the outdoor air temperature during the heating period, if the outdoor air temperature is excessively low and the heating efficiency is low, only the geothermal heat should be used as the heat source. , Efficient heating can be performed.

Further, since the load on the indoor unit side of the air conditioner becomes large at the start of the heating operation, it is preferable to use both outdoor air heat and geothermal heat as the heat source. Then, when the room temperature reaches a desired temperature and shifts to a stable state, and the air conditioner becomes a low-load operation state in which on / off repetition and output are suppressed, only geothermal heat is used as a heat source. If the switching is performed, an efficient operating state can be maintained, which is preferable.

In addition, when the temperature of the heat medium is higher than the outdoor air temperature, the heating operation is performed mainly using outdoor air heat and geothermal heat as heat sources, while the heat medium temperature is close to the outdoor air temperature. If it is expected that an excessive heat load is applied to the ground, such as when the temperature in the ground drops excessively, the system shifts to an operating state in which the heat source is only outdoor air heat, and the geothermal heat is generated. It is preferable to stop the heat absorption from the ground through the exchanger 16 and the heat exchange medium so that the underground temperature can be recovered.

(When the heat source is only air heat)
When heating the indoor space, when only the outdoor air heat is used as the heat source, that is, when only the outdoor heat exchanger 12 is used as the outdoor heat exchanger, the heat is as shown in FIG. The valves 61 and 62 of the exchanger switching valve are opened so that the outdoor heat exchanger 12 communicates with the expansion valve 14 through each valve. The flow path switching valve 15 is in a state in which the heat medium flow path a and the heat medium flow path b are communicated with each other and the heat medium flow path c and the heat medium flow path d are communicated with each other in the second flow path connection state.

When the system is operated, the indoor heat exchanger 11 exchanges heat between the indoor air introduced by being blown by a fan (not shown) and the heat medium of the gas phase as a condenser. The heat medium of the gas phase cooled by this heat exchange condenses and changes into a liquid phase. On the other hand, the indoor air is heated by the heat exchange in the indoor heat exchanger 11 and released into the indoor space in a state where the temperature is raised, and the indoor temperature is raised to a desired temperature (warming the indoor space).

The liquid phase heat medium obtained by condensing in the indoor heat exchanger 11 exits the indoor heat exchanger 11 and reaches the expansion valve 14. The expansion valve 14 expands the heat medium of the liquid phase, and the pressure and temperature are reduced.

The liquid phase heat medium whose pressure and temperature are lowered by the expansion valve 14 is discharged to the outside of the expansion valve 14, but among the heat exchanger switching valves near the geothermal heat exchanger 16, the valve 61 , 62 is opened and valves 63 and 64 are closed, so that the heat medium exiting the expansion valve 14 passes through the valves 61 and 62 and does not circulate to the geothermal heat exchanger 16 and is used for outdoor heat. Reach the exchanger 12.

As an evaporator, the outdoor heat exchanger 12 exchanges heat between the outdoor air introduced by being blown by a fan (not shown) and the heat medium of the liquid phase. The heat medium that is heated by heat exchange in the outdoor heat exchanger 12 and evaporates as the temperature rises to become a gas phase goes out of the outdoor heat exchanger 12 and opens the heat medium flow path b. It reaches the flow path switching valve 15 via the valves 73 and 74 in the state, and further goes from the flow path switching valve 15 to the compressor 13 via the heat medium flow path a. On the other hand, the outdoor air is cooled by the heat exchange in the outdoor heat exchanger 12, and is discharged into the outside air in a state where the temperature is lowered.

The heat medium of the high temperature gas phase that has left the outdoor heat exchanger 12 and reached the compressor 13 is pressurized by the compressor 13 operated by an external drive source. The heat medium of the pressurized gas phase is in a state of increasing pressure and temperature. Then, the heat medium of the gas phase that has exited the compressor 13 travels toward the indoor heat exchanger 11 via the heat medium flow path c, the flow path switching valve 15, and the heat medium flow path d.
After that, the heat medium returns to the inside of the indoor heat exchanger 11, and the heating is continuously executed by repeating each process after the heat exchange in the indoor heat exchanger 11 in the same manner as described above.

(When the heat source is air heat and geothermal heat)
When outdoor air heat and geothermal heat are used as heat sources when heating the indoor space, that is, when both the outdoor heat exchanger 12 and the geothermal heat exchanger 16 are used as the outdoor heat exchangers. As shown in FIG. 5, the valves 64 and 61 of the heat exchanger switching valve are opened, and the outdoor heat exchanger 12 is switched to a state in which the outdoor heat exchanger 12 communicates with the expansion valve 14 through the geothermal heat exchanger 16.

When the system is operated, the indoor heat exchanger 11 exchanges heat between the indoor air introduced by being blown by a fan (not shown) and the heat medium of the gas phase as a condenser. The heat medium of the gas phase cooled by this heat exchange condenses and changes into a liquid phase. On the other hand, the indoor air is heated by the heat exchange in the indoor heat exchanger 11 and released into the indoor space in a state where the temperature is raised, and the indoor temperature is raised to a desired temperature (warming the indoor space).

The liquid phase heat medium obtained by condensing in the indoor heat exchanger 11 exits the indoor heat exchanger 11 and reaches the expansion valve 14. The heat medium of the liquid phase expands at the expansion valve 14, and the pressure and temperature are lowered.

The liquid phase heat medium whose pressure and temperature are lowered by the expansion valve 14 is discharged to the outside of the expansion valve 14, but among the heat exchanger switching valves near the geothermal heat exchanger 16, the valve 61 , 63, 64 are opened and the valve 62 is closed, so that the heat medium exiting the expansion valve 14 passes through the valve 61 and the heat medium flow path e and flows to the geothermal heat exchanger 16. Become.

In the underground heat exchanger 16, the heat exchange medium introduced by being pressurized by a pump (not shown) and the heat medium exchange heat, and the liquid phase heat medium heated by this heat exchange is used. The temperature rises, and part of it evaporates and changes to the gas phase. On the other hand, the heat exchange medium is cooled by the heat exchange in the geothermal heat exchanger 16 and heads for the geothermal heat exchange unit 50 in a state where the temperature is lowered. Then, the heat exchange medium absorbs heat from the ground by the geothermal heat exchange unit 50 to raise the temperature, and then returns to the geothermal heat exchanger 16 again. The circulation of the heat exchange medium between the geothermal heat exchanger 16 and the geothermal heat exchanger 50 will be repeated as long as the heat exchange in the geothermal heat exchanger 16 is continued.

The heat medium heated by the geothermal heat exchanger 16 exits the geothermal heat exchanger 16 and then passes through the heat medium flow paths f, valves 64, and 63 to reach the outdoor heat exchanger 12.
As an evaporator, the outdoor heat exchanger 12 exchanges heat between the outdoor air introduced by being blown by a fan (not shown) and a heat medium. The heat medium that is heated by heat exchange in the outdoor heat exchanger 12 and evaporates as the temperature rises to become a gas phase goes out of the outdoor heat exchanger 12 and opens the heat medium flow path b. It reaches the flow path switching valve 15 via the valves 73 and 74 in the state, and further goes from the flow path switching valve 15 to the compressor 13 via the heat medium flow path a. On the other hand, the outdoor air is cooled by the heat exchange in the outdoor heat exchanger 12, and is discharged into the outside air in a state where the temperature is lowered.

The heat medium of the high temperature gas phase that has left the outdoor heat exchanger 12 and reached the compressor 13 is pressurized by the compressor 13 operated by an external drive source. The heat medium of the pressurized gas phase is in a state of increasing pressure and temperature. Then, the heat medium of the gas phase that has exited the compressor 13 travels toward the indoor heat exchanger 11 via the heat medium flow path c, the flow path switching valve 15, and the heat medium flow path d.
After that, the heat medium returns to the inside of the indoor heat exchanger 11, and the heating is continuously executed by repeating each process after the heat exchange in the indoor heat exchanger 11 in the same manner as described above.

(When the heat source is only geothermal heat)
When only geothermal heat is used as the heat source when heating the indoor space, that is, when only the geothermal heat exchanger 16 is used as the outdoor heat exchanger, as shown in FIG. 6, in advance. By opening the valves 75, 72, 73 of the bypass switching valve and closing the valve 74, the bypass flow path 17 communicates with the heat medium flow path b, and the heat medium exiting the bypass flow path 17 flows to the compressor 13. At the same time as switching to the state, the valves 61 and 64 of the heat exchanger switching valve are opened, and the bypass flow path 17 is switched to the state of communicating with the expansion valve 14 through the geothermal heat exchanger 16. The flow path switching valve 15 is in a state in which the heat medium flow path a and the heat medium flow path b are communicated with each other and the heat medium flow path c and the heat medium flow path d are communicated with each other in the second flow path connection state.

Similarly to the above, the indoor heat exchanger 11 exchanges heat between the indoor air introduced by being blown by a fan (not shown) and the heat medium of the gas phase as a condenser. The heat medium of the gas phase cooled by this heat exchange condenses and changes into a liquid phase. On the other hand, the indoor air is heated by the heat exchange in the indoor heat exchanger 11 and released into the indoor space in a state where the temperature is raised, and the indoor temperature is raised to a desired temperature (warming the indoor space).

The liquid phase heat medium obtained by condensing in the indoor heat exchanger 11 exits the indoor heat exchanger 11 and reaches the expansion valve 14. The expansion valve 14 expands the heat medium of the liquid phase, and the pressure and temperature are reduced.

The liquid phase heat medium whose pressure and temperature are lowered by the expansion valve 14 is discharged to the outside of the expansion valve 14, but among the heat exchanger switching valves near the geothermal heat exchanger 16, the valve 61 , 64 is opened and the valves 62 and 63 are closed, so that the heat medium exiting the expansion valve 14 passes through the valve 61 and the heat medium flow path e and flows to the geothermal heat exchanger 16. Become.

In the underground heat exchanger 16, the heat exchange medium introduced by being pressurized by a pump (not shown) and the heat medium exchange heat, and the liquid phase heat medium heated by this heat exchange is used. The temperature rises, evaporates and changes to the gas phase. On the other hand, the heat exchange medium is cooled by the heat exchange in the geothermal heat exchanger 16 and heads for the geothermal heat exchange unit 50 in a state where the temperature is lowered. Then, the heat exchange medium absorbs heat from the ground by the geothermal heat exchange unit 50 to raise the temperature, and then returns to the geothermal heat exchanger 16 again. The circulation of the heat exchange medium between the geothermal heat exchanger 16 and the geothermal heat exchanger 50 will be repeated as long as the heat exchange in the geothermal heat exchanger 16 is continued.

The gas phase heat medium obtained by evaporating in the geothermal heat exchanger 16 exits the geothermal heat exchanger 16 and then passes through the heat medium flow path f and the valve 64 to the bypass flow path 17. Reach.
On the other hand, since the other end of the bypass flow path 17 communicates with the heat medium flow path b by the valves 75, 72, 73 in the open state, the gas phase heat medium that has passed through the bypass flow path 17 can be used. It reaches the flow path switching valve 15 via the valves 75, 72, 73 and the heat medium flow path b, and further goes from the flow path switching valve 15 to the compressor 13 via the heat medium flow path a.

The heat medium of the high temperature gas phase that has reached the compressor 13 is pressurized by the compressor 13. The heat medium of the pressurized gas phase is in a state of increasing pressure and temperature. Then, the heat medium of the gas phase that has exited the compressor 13 travels toward the indoor heat exchanger 11 via the heat medium flow path c, the flow path switching valve 15, and the heat medium flow path d.
After that, the heat medium returns to the inside of the indoor side heat exchanger 11, and in the same manner as described above, each process after the heat exchange in the indoor side heat exchanger 11 is repeated to continuously execute the heating.

(When defrosting is performed using the heat source as geothermal heat)
During such heating operation, if the outdoor temperature is low, frost may form on the outer surface portion of the outdoor heat exchanger 12 that exchanges heat with air, which may hinder heat exchange with air. The defrosting operation state corresponding to such frost formation will be described.

(Defrosting operation state based on the first defrosting connection state)
When frost formation is detected during heating and defrosting is performed, the heating operation is temporarily stopped and the state shifts to the defrosting operation state. In order to perform defrosting, as shown in FIG. 7, the valves 75, 71, 73, 74 of the bypass switching valve are opened, the valves 72 are closed, and the bypass flow path 17 communicates with the heat medium flow path a. The heat medium exiting the bypass flow path 17 is switched to a state in which it flows to the compressor 13, and the valves 62 and 64 of the heat exchanger switching valves are opened, so that the bypass flow path 17 passes through the geothermal heat exchanger 16. Switch to the state of communicating with the outdoor heat exchanger 12. The flow path switching valve 15 is in the first flow path connection state, in which the heat medium flow path a and the heat medium flow path d are communicated with each other, and the heat medium flow path b and the heat medium flow path c are communicated with each other.

When the defrosting operation is executed, in the underground heat exchanger 16, heat exchange is performed between the heat exchange medium introduced by being pressurized by a pump (not shown) and the heat medium, and the heat is heated by this heat exchange. The heat medium of the liquid phase heats up and evaporates to change into a gas phase. On the other hand, the heat exchange medium is cooled by the heat exchange in the geothermal heat exchanger 16 and heads for the geothermal heat exchange unit 50 in a state where the temperature is lowered. Then, the heat exchange medium absorbs heat from the ground by the geothermal heat exchange unit 50 to raise the temperature, and then returns to the geothermal heat exchanger 16 again. The circulation of the heat exchange medium between the geothermal heat exchanger 16 and the geothermal heat exchanger 50 is repeated as long as the heat exchange in the geothermal heat exchanger 16 is continued.

The gas phase heat medium obtained by evaporating in the geothermal heat exchanger 16 exits the geothermal heat exchanger 16 and then passes through the heat medium flow path f and the valve 64 to the bypass flow path 17. To circulate.
On the other hand, since the other end of the bypass flow path 17 communicates with the heat medium flow path a by the valves 75 and 71 opened, the gas phase heat medium passing through the bypass flow path 17 is the valve 75. , 71 and the heat medium flow path a toward the compressor 13.

The heat medium of the high temperature gas phase that has reached the compressor 13 is pressurized by the compressor 13. The heat medium of the pressurized gas phase is in a state of increasing pressure and temperature. Then, the heat medium of the gas phase leaving the compressor 13 passes through the heat medium flow path c, the flow path switching valve 15, the heat medium flow path b, and the valves 73 and 74 in the open state, and then the outdoor heat exchanger. Introduced in 12.

As a condenser, the outdoor heat exchanger 12 exchanges heat between the outdoor air introduced by being blown by a fan (not shown) and the heat medium of the gas phase. The heat medium of the gas phase cooled by this heat exchange lowers its temperature and condenses into a liquid phase. On the other hand, since the outdoor air is heated by the heat exchange in the outdoor heat exchanger 12 and tries to exit the outdoor heat exchanger in a state where the temperature is raised, the frosted portion on the surface of the outdoor heat exchanger 12 is formed. , It is warmed by contact with the air that raised this temperature. In the frosted portion that is warmed in this way, the frost finally melts and becomes a defrosted state. The air after warming the frosted portion is discharged into the outside air.

The heat medium condensed by the outdoor heat exchanger 12 is discharged to the outside of the outdoor heat exchanger 12, but the valves 62 and 64 of the heat exchanger switching valves near the geothermal heat exchanger 16 are opened. When the valves 61 and 63 are closed, the heat medium exiting the outdoor heat exchanger 12 passes through the valve 62 and the heat medium flow path e and proceeds toward the geothermal heat exchanger 16. ..

After that, the heat medium returns to the inside of the geothermal heat exchanger 16, and the defrosting is continuously executed by repeating each process after the heat exchange in the geothermal heat exchanger 16 in the same manner as described above.
When the frost is melted at all the frosted points in the outdoor heat exchanger 12 and the defrosting is completed, the defrosting operation state can be returned to the heating operation state.

(Defrosting operation state based on the second defrosting connection state)
The defrosting can also be performed without using a compressor. The defrosting operation state without using this compressor will be described.

Similar to the above, defrosting is performed by temporarily stopping the heating operation and shifting to the defrosting operation state. However, in order to perform defrosting, as shown in FIG. 8, the valves 75 and 72 of the bypass switching valve, The 74 is opened, the valves 71 and 73 are closed, the bypass flow path 17 communicates with the heat medium flow path b, and the heat medium exiting the bypass flow path 17 is switched to a state in which the heat medium flows through the outdoor heat exchanger 12. As for the heat exchanger switching valve, the valves 62 and 64 are opened in the same manner as described above so that the bypass flow path 17 communicates with the outdoor heat exchanger 12 through the geothermal heat exchanger 16. The heat medium is pressurized by a pump (not shown) provided at a predetermined location in the heat medium flow path, and reaches the outdoor heat exchanger from the geothermal heat exchanger via the bypass flow path. It is assumed that the circulation path reaching the geothermal heat exchanger again can be continuously circulated.

When the defrosting operation is executed, in the underground heat exchanger 16, heat exchange is performed between the heat exchange medium introduced by being pressurized by a pump (not shown) and the heat medium, and the heat is heated by this heat exchange. The heat medium of the liquid phase will heat up. On the other hand, the heat exchange medium is cooled by the heat exchange in the geothermal heat exchanger 16 and heads for the geothermal heat exchange unit 50 in a state where the temperature is lowered. Then, the heat exchange medium absorbs heat from the ground by the geothermal heat exchange unit 50 to raise the temperature, and then returns to the geothermal heat exchanger 16 again. The circulation of the heat exchange medium between the geothermal heat exchanger 16 and the geothermal heat exchanger 50 is repeated as long as the heat exchange in the geothermal heat exchanger 16 is continued.

The heat medium heated by the geothermal heat exchanger 16 exits the geothermal heat exchanger 16 and then passes through the heat medium flow path f and the valve 64 and flows to the bypass flow path 17.
On the other hand, the other end of the bypass flow path 17 communicates with the heat medium flow path b by the valves 75 and 72 in the open state, and the valve 73 is closed and the valve 74 is open in the heat medium flow path b. The heat medium that has passed through the bypass flow path 17 is introduced into the outdoor heat exchanger 12 via the valves 75 and 72, the heat medium flow path b, and the valve 74.

In the outdoor heat exchanger 12, the outdoor air introduced by being blown by a fan (not shown) and the heat medium exchange heat, and the heat medium cooled by this heat exchange lowers the temperature. On the other hand, since the outdoor air is heated by the heat exchange in the outdoor heat exchanger 12 and tries to exit the outdoor heat exchanger 12 in a state where the temperature is raised, the frosted portion on the surface of the outdoor heat exchanger 12 Is warmed in contact with the air that raised this temperature. In the frosted portion that is warmed in this way, the frost melts and defrosting proceeds. The air after warming the frosted portion is discharged into the outside air.

The heat medium whose temperature has been lowered by the outdoor heat exchanger 12 is discharged to the outside of the outdoor heat exchanger 12, but among the heat exchanger switching valves near the geothermal heat exchanger 16, the valve 62, When 64 is opened and the valves 61 and 63 are closed, the heat medium exiting the outdoor heat exchanger 12 passes through the valve 62 and the heat medium flow path e and proceeds toward the geothermal heat exchanger 16. It will be.

After that, the heat medium returns to the inside of the geothermal heat exchanger 16, and the defrosting is continuously executed by repeating each process after the heat exchange in the geothermal heat exchanger 16 in the same manner as described above.
When the frost is melted at all the frosted points in the outdoor heat exchanger 12 and the defrosting is completed, the defrosting operation state can be returned to the heating operation state.

In addition, in response to the case where geothermal heat is used as the heat source during heating as described above, heat is absorbed from the outdoor air during times when heating operation is not required, such as at night or when there are no people in the room. It is also possible to execute the operation as a cycle of releasing the heat to the ground, and to positively recover the underground temperature lowered by the heat absorption accompanying the heating operation and store the heat in the ground.

In order to perform the operation for recovering the underground temperature or the like, the heat medium leaving the compressor 13 reaches the geothermal heat exchanger 16 through the bypass flow path 17, and heat is generated from the geothermal heat exchanger 16. The bypass switching valves 71, 72, 73, 74, 75 are set so that the medium reaches the outdoor heat exchanger 12 and further returns to the compressor 13, and the heat exchanger switching valve valves 62, 64 is opened so that the bypass flow path 17 communicates with the outdoor heat exchanger 12 through the geothermal heat exchanger 16. The flow path switching valve 15 is in the first flow path connection state, in which the heat medium flow path a and the heat medium flow path d are communicated with each other, and the heat medium flow path b and the heat medium flow path c are communicated with each other.

When the operation is executed, in the geothermal heat exchanger 16, the heat exchange medium introduced by being pressurized by a pump (not shown) and the heat medium exchange heat, and the air cooled by this heat exchange is exchanged. The heat medium of the phase lowers the temperature, and part of it condenses and changes to a liquid phase. On the other hand, the heat exchange medium is heated by the heat exchange in the geothermal heat exchanger 16 and heads for the geothermal heat exchange unit 50 in a state where the temperature is raised. Then, the heat exchange medium releases heat into the ground by the geothermal heat exchange unit 50 to lower the temperature, and then returns to the geothermal heat exchanger 16 again. The circulation of the heat exchange medium between the geothermal heat exchanger 16 and the geothermal heat exchange unit 50 is repeated for the duration of the operation, and the heat exchange medium releases heat into the ground. The temperature in the ground can be raised.

The heat medium whose temperature has been lowered by the geothermal heat exchanger 16 exits the geothermal heat exchanger 16 and then passes through the heat medium flow path e and the valve 62 to reach the outdoor heat exchanger 12. The outdoor heat exchanger 12 exchanges heat between the outdoor air introduced by being blown by a fan (not shown) and the heat medium. The heat medium that is heated by heat exchange in the outdoor heat exchanger 12 and evaporates as the temperature rises to become a gas phase goes out of the outdoor heat exchanger 12 and faces the compressor 13. On the other hand, the outdoor air is cooled by the heat exchange in the outdoor heat exchanger 12, and is discharged into the outside air in a state where the temperature is lowered.

The heat medium of the high temperature gas phase that has left the outdoor heat exchanger 12 and reached the compressor 13 is pressurized by the compressor 13 to increase the pressure and temperature. Then, the heat medium of the gas phase exiting the compressor 13 passes through the bypass flow path 17, passes through the valve 64 and the heat medium flow path f, and proceeds toward the geothermal heat exchanger 16.

After that, the heat medium returns to the inside of the geothermal heat exchanger 16, and each process after the heat exchange in the geothermal heat exchanger 16 is repeated in the same manner as described above.
When the underground temperature rises to an appropriate temperature or the time zone for heating the indoor space is reached, the operation related to the recovery of the underground temperature is stopped and the operation is shifted to the heating operation as necessary. ..

As described above, in the heat pump system according to the present embodiment, the underground heat exchanger 16 is located at a predetermined position in the heat medium flow path of the heat pump via the heat exchanger switching valves 61, 62, 63, 64. In a state where the heat medium is circulated so as to be intervening, the underground heat exchanger 16 is connected in series with the outdoor heat exchanger 12, and the heat medium circulated in the outdoor heat exchanger 12 is in a positional relationship. Since it is also distributed to the underground heat exchanger 16 as it is, when the indoor heat exchanger 11 acts as an evaporator during cooling, the outdoor heat exchanger 12 mainly lowers the heat medium temperature, and the underground heat exchanger 11 16 can mainly condense the heat medium, and during heating when the indoor heat exchanger 12 acts as a condenser, the underground heat exchanger 16 mainly raises the heat medium temperature and the outdoor heat exchanger. The load related to heat exchange can be shared between the outdoor heat exchanger 12 and the underground heat exchanger 16, such that the heat medium can be mainly evaporated in 12, and the underground heat exchange is particularly performed during heating. The vessel 16 plays the role of a preheating heat exchanger in front of the outdoor heat exchanger 12, and the heat medium in the outdoor heat exchanger 12 rises as the temperature rises in front of the outdoor heat exchanger 12. By reducing the heat exchange in the sensible heat region and improving the efficiency of heat transfer from the air to the heat medium in the outdoor heat exchanger 12 forming the evaporator, the loss can be suppressed and the heat exchange performance can be improved. Cooling and heating can be performed efficiently.

Further, a bypass flow path 17 connecting the underground heat exchanger 16 and the inlet side of the compressor 13 is provided, and the heat medium does not pass through the indoor heat exchanger 11 but passes through the bypass flow path to heat the compressor 13 and the outdoor side. By creating a state in which the exchanger 12 and the underground heat exchanger 16 circulate, the outdoor heat exchanger 12 becomes frosted around the heat exchanger due to the temperature drop due to heat absorption during heating. When it reaches, the underground heat taken into the heat medium by the underground heat exchanger 16 is introduced into the outdoor heat exchanger 12 via the compressor 13, and the heat is discharged to the outside by the outdoor heat exchanger 12. By releasing it, defrosting becomes possible, and defrosting can be performed efficiently without affecting the indoor heat exchanger 11 by utilizing the underground heat, and the deterioration of heat exchange performance due to frost formation is minimized. In addition to being suppressed, it is not necessary to generate heat separately for defrosting, and energy consumption related to defrosting can be suppressed.

(Second Embodiment of the present invention)
A second embodiment of the present invention will be described with reference to FIGS. 9 to 14. Also in this embodiment, an example in which the heat pump is applied to an air conditioner having an indoor unit and an outdoor unit will be described.

In each of the drawings, the heat pump system 2 according to the present embodiment has an indoor heat exchanger 21, an outdoor heat exchanger 22, a compressor 23, an expansion valve 24, and a flow path, as in the first embodiment. The switching valve 25, the underground heat exchanger 26, the heat exchanger switching valves 65, 66, 67, 68, the bypass flow path 27, and the bypass switching valves 76, 77 are provided, but they are different. As an indoor heat exchanger 21, the indoor heat exchanger 21 is arranged in the same manner as that provided in the indoor unit portion of the air conditioner using a known heat pump cycle, and the outdoor heat exchange is arranged outdoors. The vessel 22, the compressor 23, the expansion valve 24, and the flow path switching valve 25 are arranged in the same manner as those provided in the outdoor unit portion of the air exchanger using the known heat pump cycle, and the known air exchanger. In this case, the underground heat exchanger is located at a location corresponding to a heat medium flow path connection point at the boundary between indoors and outdoors between the indoor heat exchanger 21 in the room and each of the devices arranged outdoors. 26, the heat exchanger switching valves 65, 66, 67, 68, the bypass flow path 27, and the heat medium circuit portion including the bypass switching valves 76, 77 are arranged so as to be inserted and added. ..

The first configuration of the indoor heat exchanger 21, the outdoor heat exchanger 22, the compressor 23, the expansion valve 24, the flow path switching valve 25, and the geothermal heat exchanger 26 is the first. It is the same as the embodiment of the above, and detailed description thereof will be omitted.

In the indoor heat exchanger 21, one heat medium inflow port is connected to a bypass switching valve 77 via a predetermined heat medium flow path, for example, a pipeline, and the other heat medium inflow port is connected to a predetermined heat. It is connected to the heat exchanger switching valve 65 via the medium flow path. Then, one heat medium inflow outlet of the indoor heat exchanger 21 can communicate with the flow path switching valve 25 via the bypass switching valve 77, and the other heat medium inflow outlet is for heat exchanger switching. It is possible to communicate with the expansion valve 24 via the valves 65 and 67.

In the outdoor heat exchanger 22, one heat medium inflow port is connected to a flow path switching valve 25 via a predetermined heat medium flow path, for example, a pipeline, and the other heat medium inflow port is designated. It is connected to the expansion valve 24 via a heat medium flow path.

In the expansion valve 24, one valve opening is connected to heat exchanger switching valves 67 and 68 via a predetermined heat medium flow path, and the other valve opening is connected to outdoor heat through a predetermined heat medium flow path. It is arranged so as to be connected to the exchanger 22.

The flow path switching valve 25 communicates one heat medium inflow outlet of the outdoor heat exchanger 22 with the compressor 23 outlet, and one heat medium inflow outlet of the indoor heat exchanger 21 with the compressor 23 inlet. The first flow path connection state that enables communication and one heat medium inflow outlet of the outdoor heat exchanger 22 are communicated with the compressor 23 inlet, and one heat medium inflow outlet of the indoor heat exchanger 21 is compressed. The second flow path connection state that enables communication with the machine 23 outlet can be switched.
The flow path switching valve 25 is not limited to a single valve such as a four-way valve, and may be configured by a combination of a plurality of valves capable of obtaining the same function.

The geothermal heat exchanger 26 is arranged outdoors so as to be able to intervene between the indoor heat exchanger 21 and the expansion valve 24 in the heat pump cycle. The geothermal heat exchanger 26 is connected to the heat medium flow path between the indoor heat exchanger 21 and the expansion valve 24 via heat exchanger switching valves 65, 66, 67, 68. In these plurality of valves, the heat medium side flow path of the geothermal heat exchanger 26 is enabled to flow the heat medium and is interposed between the indoor heat exchanger 21 and the expansion valve 24, and the ground. It is a mechanism that makes it possible to switch between a state in which the medium heat heat exchanger 26 does not intervene at all.
An auxiliary expansion valve 28 is provided between the geothermal heat exchanger 26 and the heat exchanger switching valve 66.

The heat exchanger switching valves 65, 66, 67, 68 are between the indoor heat exchanger 22 and the geothermal heat exchanger 26, and between the geothermal heat exchanger 26 and the expansion valve 24. The geothermal heat exchanger 26 is arranged in each of the heat medium flow paths of the above, and the geothermal heat exchanger 26 is interposed between the indoor heat exchanger 21 and the expansion valve 24 so that the heat medium can flow, and the indoor heat exchanger 21. And the expansion valve 24 are directly connected so that the geothermal heat exchanger 26 is not interposed in the middle, and the state in which the heat medium is not circulated in the geothermal heat exchanger 26 can be switched.

Specifically, the flow state and the flow stop state of the heat medium between the heat medium flow path k connected to one heat medium inflow port of the underground heat exchanger 26 and the indoor heat exchanger 21. The first heat exchanger switching valve 65 for switching the above and the heat medium flow path k connected to one of the heat medium inflow ports of the underground heat exchanger 26 are arranged in the underground heat exchanger 26. A second heat exchanger switching valve 66 that switches between a flow state and a flow stop state of the heat medium, and a heat medium flow path k and an expansion valve connected to one heat medium inflow port of the underground heat exchanger 26. A heat medium connected to a third heat exchanger switching valve 67 that switches between a flow state and a flow stop state of the heat medium between 24 and the other heat medium inflow port of the underground heat exchanger 26. It is configured to include a fourth heat exchanger switching valve 68 for switching between a flow state and a flow stop state of the heat medium between the flow path l and the expansion valve 24.

In these heat exchanger switching valves 65, 66, 67, 68, the first heat exchanger switching valve 65 is opened, the second heat exchanger switching valve 66 is opened, and the third heat exchanger is opened. By closing the switching valve 67 and opening the fourth heat exchanger switching valve 68, the expansion valve 24 to the fourth heat exchanger switching valve 68, the underground heat exchanger 26, and the second The heat medium can flow through the heat exchanger switching valve 66 and the first heat exchanger switching valve 65 to the indoor heat exchanger 21, and the indoor heat exchanger 21 and the expansion valve 24 The underground heat exchanger 26 can intervene the heat medium in a flowable state between the two (see FIGS. 10 and 12).

Further, the first heat exchanger switching valve 65 is opened, the second heat exchanger switching valve 66 is closed, the third heat exchanger switching valve 67 is opened, and the fourth heat exchanger is opened. By closing the switching valve 68, heat is transferred from the expansion valve 24 through the third heat exchanger switching valve 67 and the first heat exchanger switching valve 65 to the indoor heat exchanger 21. A state in which the medium can be circulated, the indoor heat exchanger 21 and the expansion valve 24 are directly connected, the underground heat exchanger 26 is not interposed in the middle, and the heat medium is not circulated through the underground heat exchanger 26. (See FIGS. 9 and 11).

In addition, the first heat exchanger switching valve 65 and the third heat exchanger switching valve 67 are closed, respectively, and the second heat exchanger switching valve 66 and the fourth heat exchanger switching valve 68 are closed. By opening each of the above, the expansion valve 24 to the fourth heat exchanger switching valve 68 are opened while stopping the flow of the heat medium between the indoor heat exchanger 21 and the underground heat exchanger 26. Then, the heat medium can be circulated in the path leading to the underground heat exchanger 26, and the heat medium can be circulated between the outdoor heat exchanger 22 and the underground heat exchanger 26 via the expansion valve 24. On the other hand, it is possible to establish a flow path connection state in which the flow of the heat medium between the underground heat exchanger 26 and the indoor heat exchanger 21 is not permitted (see FIGS. 13 and 14).

One end of the bypass flow path 27 is connected to the heat medium flow path k connected to one of the heat medium inflow outlets of the geothermal heat exchanger 26, and the other end is connected to the flow path switching valve 25. In addition, the heat medium can be connected to one of the heat medium inflow outlets of the indoor heat exchanger 21 via the bypass switching valve 77, and the heat medium is circulated as needed.

One end of the bypass flow path 27 is connected to the heat medium flow path k provided with the second heat exchanger switching valve 66 among the heat exchanger switching valves, so that the second heat exchanger switching valve can be used. When the valve 66 is opened, it communicates with the geothermal heat exchanger 26, while when the second heat exchanger switching valve 66 is closed, it does not communicate with the geothermal heat exchanger 26. It is a mechanism that allows the communication state to the exchanger 26 to be switched as needed.

Further, after closing the third heat exchanger switching valve 67 with respect to one end of the bypass flow path 27, the fourth heat exchanger switching valve 68 is inserted together with the second heat exchanger switching valve 66. By opening, one end of the bypass flow path 27 is in a state of communicating with the expansion valve 24 and the outdoor heat exchanger 22 through the underground heat exchanger 26, and the bypass flow path 27 is connected to the geothermal heat exchanger 26. The heat medium can be circulated through the path from the expansion valve 24 to the outdoor heat exchanger 22. Then, in this case, if the first heat exchanger switching valve 65 is closed, the flow of the heat medium to the indoor heat exchanger 21 can be blocked, and instead of the heat medium passing through the indoor heat exchanger 21. The state of passing through the bypass flow path 27 can be set (see FIGS. 13 and 14).

The bypass switching valves 76 and 77 can switch the connection relationship between the other end of the bypass flow path 27, the flow path switching valve 25, and one heat medium inflow port of the indoor heat exchanger 21. Is what you do.

Specifically, as the bypass switching valve, the first bypass switching valve 76, which is arranged in the bypass flow path 27 and switches between the flow state and the flow stop state of the heat medium in the bypass flow path 27, and the indoor side. A second bypass switch for switching between the flow state and the flow stop state of the heat medium between one heat medium inflow port of the heat exchanger 22 and the other end of the bypass flow path 27 and the flow path switching valve 25. It is configured to include a valve 77.

In these bypass switching valves 76 and 77, by closing the first bypass switching valve 76 and opening the second bypass switching valve 77, the heat medium does not flow through the bypass flow path 27 and the heat medium does not flow. , The heat medium can flow from the flow path switching valve 25 to the heat medium flow path from the flow path switching valve 25 to the indoor heat exchanger 21 via the second bypass switching valve 77, and normal cooling or normal cooling without using the bypass flow path 27 or The connection state at the time of heating can be obtained. That is, a connection during cooling in which one heat medium inflow outlet in the indoor heat exchanger 21 is communicated with the compressor 23 inlet and one heat medium inflow outlet in the outdoor heat exchanger 22 is communicated with the compressor 23 outlet. State (see FIGS. 9 and 10), one heat medium inflow outlet in the indoor heat exchanger 21 is communicated with the compressor 23 outlet, and one heat medium inflow outlet in the outdoor heat exchanger 22 is the compressor. The connection state at the time of heating (see FIGS. 11 and 12) can be set to communicate with the 23 entrances.

Further, by opening the first bypass switching valve 76 and closing the second bypass switching valve 77, the bypass flow path 27 communicates with the flow path switching valve 25, while the flow path switching valve 25 is used. The valve 25 and one of the heat medium inflow outlets of the indoor heat exchanger 21 do not communicate with each other, and the heat medium flows from the flow path switching valve 25 through the first bypass switching valve 76 to the entire bypass flow path 27. This makes it possible, and a state is obtained in which the other end of the bypass flow path 27 is communicated with the inlet of the compressor 23 through the flow path switching valve 25, and the heat medium can be circulated from the bypass flow path 27 toward the compressor 23 (FIG. See 13).

In this state, the first heat exchanger switching valve 65 is closed, the second heat exchanger switching valve 66 is opened, and the third heat exchanger switching valve is opened on one end side of the bypass flow path 27. By closing 67 and opening the fourth heat exchanger switching valve 68, the bypass flow path 27 communicates with the expansion valve 24 and the outdoor heat exchanger 22 through the underground heat exchanger 26, and the chamber The heat medium can flow from the outer heat exchanger 22 to the bypass flow path 27 via the expansion valve 24 and the underground heat exchanger 26, while the heat medium does not flow to the indoor heat exchanger 21, resulting in heat. Instead of passing through the indoor heat exchanger 21, the medium passes through the bypass flow path 27 and reaches the compressor 23.

As a result, the heat medium flows from the compressor 23 through the flow path switching valve 25 in the first flow path connection state into the outdoor heat exchanger 22, and from the outdoor heat exchanger 22 via the expansion valve 24 to the ground. A state in which the heat medium exiting the geothermal heat exchanger 26 is returned to the compressor 23 through the bypass flow path 27 toward the medium heat exchanger 26, that is, the geothermal heat exchanger. In 26, the heat medium is heated by geothermal heat, the heat medium is made high pressure by the compressor 23, heat is released from the heat medium by the outdoor heat exchanger 22, and the heat is removed by the outdoor heat exchanger 22. A defrosting connection state capable of frosting will be obtained.

Next, the operating state of the heat pump system according to the present embodiment will be described.
First, a state in which the heat pump system is operated to cool the indoor space will be described.
When cooling, the state in which the heat source is only outdoor air heat or both air heat and geothermal heat can be switched according to the indoor, outdoor, and underground conditions.

For example, when the temperature of the heat medium is lower than the outdoor air temperature, the cooling operation is performed with the outdoor air heat and the underground heat mainly used as heat sources, while the heat medium temperature becomes a value close to the outdoor air temperature. If it is expected that an excessive heat load is applied to the ground, such as when the temperature in the ground rises excessively, the system shifts to an operating state in which the heat source is only outdoor air heat, and the heat is exchanged in the ground. It is preferable to stop the release of heat into the ground through the vessel 26 and the heat exchange medium so that the ground temperature can be recovered.

(When the heat source is only air heat)
When cooling the indoor space, when only outdoor air heat is used as the heat source, that is, when only the outdoor heat exchanger 22 is used as the outdoor condenser, heat is shown as shown in FIG. The valves 67 and 65 of the exchanger switching valve are opened and the valves 66 and 68 are closed so that the outdoor heat exchanger 22 communicates with the indoor heat exchanger 21 through the expansion valve 24 and each valve. Further, the valve 76 of the bypass switching valve is closed, the valve 77 is opened, and the flow path switching valve 25 is in the first flow path connection state, and the indoor heat exchanger 21 and the compressor 23 inlet are communicated with each other. The outdoor heat exchanger 22 and the compressor 23 outlet are connected to each other.

When the system is operated, the indoor heat exchanger 21, as an evaporator, exchanges heat between the indoor air introduced by being blown by a fan (not shown) and the heat medium of the liquid phase. The heat medium that is heated by heat exchange in the indoor heat exchanger 21 and evaporates as the temperature rises to become a gas phase goes out of the indoor heat exchanger 21 and heats the bypass switching valve 77. It goes to the compressor 23 via the medium flow path j, the flow path switching valve 25, and the heat medium flow path g. On the other hand, the indoor air is cooled by the heat exchange in the indoor heat exchanger 21 and released into the indoor space in a state where the temperature is lowered, and the indoor temperature is lowered to a desired temperature (cooling the indoor space).

The heat medium of the high temperature gas phase that has left the indoor heat exchanger 21 and reached the compressor 23 is pressurized by the compressor 23, and the pressure and temperature are increased. Then, the heat medium of the gas phase exiting the compressor 23 is introduced into the outdoor heat exchanger 22 via the heat medium flow path i, the flow path switching valve 25, and the heat medium flow path h.

The outdoor heat exchanger 22 exchanges heat between the outdoor air introduced by being blown by a fan (not shown) and the heat medium of the gas phase as a condenser. The heat medium of the gas phase cooled by this heat exchange condenses and changes into a liquid phase. On the other hand, the outdoor air is heated by the heat exchange in the outdoor heat exchanger 22, and is discharged into the outside air in a state where the temperature is raised.

The liquid phase heat medium obtained by condensing in the outdoor heat exchanger 22 is discharged to the outside of the outdoor heat exchanger 22 and reaches the expansion valve 24. With this expansion valve 24, the heat medium expands to reduce the pressure and temperature, and then tries to go to the indoor heat exchanger 21, but the heat in the vicinity of the geothermal heat exchanger 26 Of the exchanger switching valves, the valves 67 and 65 are opened and the valves 66 and 68 are closed, so that the heat medium exiting the expansion valve 24 passes through the valves 67 and 65 and is a geothermal heat exchanger. It will proceed toward the indoor heat exchanger 21 without being distributed to the 26.
After that, the heat medium returns to the inside of the indoor heat exchanger 21, and in the same manner as described above, each process after the heat exchange in the indoor heat exchanger 21 is repeated to continuously execute the cooling.

(When the heat source is air heat and geothermal heat)
When outdoor air heat and geothermal heat are used as heat sources when cooling the indoor space, that is, when both the outdoor heat exchanger 22 and the geothermal heat exchanger 26 are used as the outdoor condenser. As shown in FIG. 10, the valves 65, 66, 68 of the heat exchanger switching valve are opened, the valve 67 is closed, and the outdoor heat exchanger 22 and the expansion valve 24 are geothermal heat exchangers. The state is switched to the state of communicating with the indoor heat exchanger 21 through 26.

When the system is operated, the indoor heat exchanger 21, as an evaporator, exchanges heat between the indoor air introduced by being blown by a fan (not shown) and the heat medium of the liquid phase. The heat medium that is heated by heat exchange in the indoor heat exchanger 21 and evaporates as the temperature rises to become a gas phase goes out of the indoor heat exchanger 21 and heats the bypass switching valve 77. It goes to the compressor 23 via the medium flow path j, the flow path switching valve 25, and the heat medium flow path g. On the other hand, the indoor air is cooled by the heat exchange in the indoor heat exchanger 21 and released into the indoor space in a state where the temperature is lowered, and the indoor temperature is lowered to a desired temperature (cooling the indoor space).

The heat medium of the high temperature gas phase that has left the indoor heat exchanger 21 and reached the compressor 23 is pressurized by the compressor 23. The heat medium of the pressurized gas phase is in a state of increasing pressure and temperature. Then, the heat medium of the gas phase exiting the compressor 23 is introduced into the outdoor heat exchanger 22 via the heat medium flow path i, the flow path switching valve 25, and the heat medium flow path h.

The outdoor heat exchanger 22 exchanges heat between the outdoor air introduced by being blown by a fan (not shown) and the heat medium of the gas phase as a condenser. The heat medium of the gas phase cooled by this heat exchange lowers its temperature, and a part of it condenses and changes into a liquid phase. On the other hand, the outdoor air is heated by the heat exchange in the outdoor heat exchanger 22, and is discharged into the outside air in a state where the temperature is raised.

The heat medium whose temperature has been lowered by the outdoor heat exchanger 22 is discharged to the outside of the outdoor heat exchanger 22 and reaches the expansion valve 24. In this expansion valve 24, the heat medium expands to reduce the pressure and temperature, and then exits the expansion valve 24. Among the heat exchanger switching valves in the vicinity of the geothermal heat exchanger 26, , Valves 65, 66, 68 are opened and the valve 67 is closed, so that the heat medium exiting the expansion valve 24 passes through the heat medium flow path l and the valve 68 and flows to the geothermal heat exchanger 26. Will be done.

In the geothermal heat exchanger 26, the heat exchange medium introduced by being pressurized by a pump (not shown) exchanges heat with the heat medium, and the heat medium of the gas phase cooled by this heat exchange is used. It will condense and change to a liquid phase. On the other hand, the heat exchange medium is heated by the heat exchange in the geothermal heat exchanger 26, and heads for the geothermal heat exchange unit 50 in a state where the temperature is raised. Then, the heat exchange medium releases heat into the ground by the geothermal heat exchange unit 50 to lower the temperature, and then returns to the geothermal heat exchanger 26 again. The circulation of the heat exchange medium between the geothermal heat exchanger 26 and the geothermal heat exchanger 50 will be repeated as long as the heat exchange in the geothermal heat exchanger 26 is continued.

The liquid phase heat medium obtained by condensing with the underground heat exchanger 26 is the heat medium after leaving the underground heat exchanger 26 and further reducing the pressure and temperature with the auxiliary expansion valve 28. It passes through the flow paths k, valves 66, and 65 and proceeds toward the indoor heat exchanger 21.
After that, the heat medium returns to the inside of the indoor heat exchanger 21, and in the same manner as described above, each process after the heat exchange in the indoor heat exchanger 21 is repeated to continuously execute the cooling.

In addition, in response to the case where geothermal heat is used as the heat source during cooling as described above, heat is taken from the ground and the heat is taken from the ground during times when cooling operation is not required, such as at night or when there are no people in the room. It is also possible to execute the operation as a cycle in which the air is released to the outdoor air, and to actively recover the underground temperature that has risen due to the heat release accompanying the cooling operation and store the cold heat in the ground.

In order to perform the operation for recovering the underground temperature or the like, the valve 76 of the bypass switching valve is opened, the valve 77 is closed, the bypass flow path 27 communicates with the heat medium flow path j, and the bypass flow path The heat medium exiting 27 is switched to a state in which it flows through the flow path switching valve 25, the valves 66 and 68 of the heat exchanger switching valve are opened, the valves 65 and 67 are closed, and the bypass flow path 27 is underground. The state is switched to communicate with the expansion valve 24 and the outdoor heat exchanger 22 through the heat heat exchanger 26. The flow path switching valve 25 is in the first flow path connection state, and the heat medium flow path g and the heat medium flow path j are communicated with each other, and the heat medium flow path h and the heat medium flow path i are communicated with each other to cause a bypass flow. The road 27 and the inlet of the compressor 23 are communicated with each other, and the outdoor heat exchanger 22 and the outlet of the compressor 23 are communicated with each other (see FIG. 13).

When the operation is executed, in the underground heat exchanger 26, the heat exchange medium introduced by being pressurized by a pump (not shown) and the heat medium exchange heat, and the liquid heated by this heat exchange. The heat medium of the phase heats up and evaporates to change into a gas phase. On the other hand, the heat exchange medium is cooled by the heat exchange in the geothermal heat exchanger 26, and heads for the geothermal heat exchange unit 50 in a state where the temperature is lowered. Then, the heat exchange medium absorbs heat from the ground by the geothermal heat exchange unit 50 to raise the temperature, and then returns to the geothermal heat exchanger 26 again. The circulation of the heat exchange medium between the geothermal heat exchanger 26 and the geothermal heat exchange unit 50 is repeated for the duration of the operation, and the heat exchange medium absorbs heat from the ground. The temperature in the ground can be lowered.

The gas phase heat medium obtained by evaporating in the geothermal heat exchanger 26 passes through the heat medium flow path k, the auxiliary expansion valve 28, and the valve 66 after leaving the geothermal heat exchanger 26. And circulates in the bypass flow path 27.
On the other hand, since the other end of the bypass flow path 27 communicates with the flow path switching valve 25, the heat medium of the gas phase that has passed through the bypass flow path 27 through the valve 76 in the open state flows through the flow path. It goes to the compressor 23 via the switching valve 25.

The heat medium of the high temperature gas phase that has reached the compressor 23 is pressurized by the compressor 23, and the pressure and temperature are increased. Then, the heat medium of the gas phase exiting the compressor 23 is introduced into the outdoor heat exchanger 22 via the heat medium flow path i, the flow path switching valve 25, and the heat medium flow path h.

In the outdoor heat exchanger 22, the outdoor air introduced by being blown by a fan (not shown) and the heat medium of the gas phase exchange heat, and the heat medium of the gas phase cooled by this heat exchange is the heat medium. It lowers the temperature and condenses into a liquid phase. On the other hand, the outdoor air is heated by the heat exchange in the outdoor heat exchanger 22, and is discharged into the outside air in a state where the temperature is raised.

The heat medium condensed by the outdoor heat exchanger 22 is discharged to the outside of the outdoor heat exchanger 22 and reaches the expansion valve 24. In this expansion valve 24, the heat medium expands to reduce the pressure and temperature, and then exits the expansion valve 24. Among the heat exchanger switching valves in the vicinity of the geothermal heat exchanger 26, , Valves 66 and 68 are opened and valves 65 and 67 are closed, so that the heat medium exiting the expansion valve 24 passes through the heat medium flow path l and the valve 68 to the geothermal heat exchanger 26. It will move toward.

After that, the heat medium returns to the inside of the geothermal heat exchanger 26, and each process after the heat exchange in the geothermal heat exchanger 26 is repeated in the same manner as described above.
When the underground temperature drops to an appropriate temperature or the time zone for cooling the indoor space is reached, the operation related to the recovery of the underground temperature is stopped and the operation is shifted to the cooling operation as necessary. ..

Subsequently, a state in which the heat pump system is operated to heat the indoor space will be described.
When heating, as in the case of cooling, the state where the heat source is only outdoor air heat or both air heat and geothermal heat is switched according to the indoor, outdoor, and underground conditions. Can be done.

For example, in a situation where the temperature of the heat medium is higher than the outdoor air temperature, the heating operation is performed with the outdoor air heat and the geothermal heat mainly used as heat sources, while the heat medium temperature becomes a value close to the outdoor air temperature. If it is expected that an excessive heat load is applied to the ground, such as when the underground temperature drops excessively, the system shifts to an operating state in which the heat source is only outdoor air heat, and geothermal heat exchange occurs. It is preferable to stop the heat absorption from the ground through the vessel 26 and the heat exchange medium so that the ground temperature can be recovered.

(When the heat source is only air heat)
When heating the indoor space, when only the outdoor air heat is used as the heat source, that is, when only the outdoor heat exchanger 22 is used as the outdoor heat exchanger, the heat is as shown in FIG. The valves 65 and 67 of the exchanger switching valve are opened and the valves 66 and 68 are closed so that the outdoor heat exchanger 22 and the expansion valve 24 communicate with the indoor heat exchanger 21 through the respective valves. Further, the valve 76 of the bypass switching valve is closed, the valve 77 is opened, and the flow path switching valve 25 is in the second flow path connection state, and the heat medium flow path g and the heat medium flow path h are communicated with each other to generate heat. By communicating the medium flow path i and the heat medium flow path j, the indoor heat exchanger 21 and the compressor 23 outlet are communicated with each other, and the outdoor heat exchanger 22 and the compressor 23 inlet are communicated with each other. To do.

When the system is operated, the indoor heat exchanger 21 exchanges heat between the indoor air introduced by being blown by a fan (not shown) and the heat medium of the gas phase as a condenser. The heat medium of the gas phase cooled by this heat exchange condenses and changes into a liquid phase. On the other hand, the indoor air is heated by the heat exchange in the indoor heat exchanger 21 and released into the indoor space in a state where the temperature is raised, and the indoor temperature is raised to a desired temperature (warming the indoor space).

The liquid phase heat medium obtained by condensing in the indoor heat exchanger 21 is discharged to the outside of the indoor heat exchanger 21, but in the heat exchanger switching valve near the geothermal heat exchanger 26. When the valves 65 and 67 are opened and the valves 66 and 68 are closed, the heat medium exiting the indoor heat exchanger 21 passes through the valves 65 and 67 and is distributed to the geothermal heat exchanger 26. It reaches the expansion valve 24 without doing anything.

The heat medium of the liquid phase expands at the expansion valve 24, and the pressure and temperature are reduced. The liquid phase heat medium whose pressure and temperature are lowered by the expansion valve 24 is discharged to the outside of the expansion valve 24 and reaches the outdoor heat exchanger 22.

The outdoor heat exchanger 22 exchanges heat between the outdoor air introduced by being blown by a fan (not shown) and the heat medium of the liquid phase as an evaporator. The heat medium that is heated by heat exchange in the outdoor heat exchanger 22 and evaporates as the temperature rises to become a gas phase goes out of the outdoor heat exchanger 22 and passes through the heat medium flow path h. It reaches the flow path switching valve 25, and further flows from the flow path switching valve 25 to the compressor 23 via the heat medium flow path g. On the other hand, the outdoor air is cooled by the heat exchange in the outdoor heat exchanger 22, and is discharged into the outside air in a state where the temperature is lowered.

The heat medium of the high temperature gas phase that has left the outdoor heat exchanger 22 and reached the compressor 23 is pressurized by the compressor 23. The heat medium of the pressurized gas phase is in a state of increasing pressure and temperature. Then, the heat medium of the gas phase that has exited the compressor 23 travels toward the indoor heat exchanger 21 via the flow path switching valve 15 and the bypass switching valve 77.
After that, the heat medium returns to the inside of the indoor heat exchanger 21, and the heating is continuously executed by repeating each process after the heat exchange in the indoor heat exchanger 21 in the same manner as described above.

(When the heat source is air heat and geothermal heat)
When outdoor air heat and geothermal heat are used as heat sources when heating the indoor space, that is, when both the outdoor heat exchanger 22 and the geothermal heat exchanger 26 are used as the outdoor heat exchangers. As shown in FIG. 12, the valves 65, 66, 68 of the heat exchanger switching valve are opened, the valve 67 is closed, and the outdoor heat exchanger 22 and the expansion valve 24 are geothermal heat exchangers. The state is switched to the state of communicating with the indoor heat exchanger 21 through 26.

When the system is operated, the indoor heat exchanger 21 exchanges heat between the indoor air introduced by being blown by a fan (not shown) and the heat medium of the gas phase as a condenser. The heat medium of the gas phase cooled by this heat exchange condenses and changes into a liquid phase. On the other hand, the indoor air is heated by the heat exchange in the indoor heat exchanger 21 and released into the indoor space in a state where the temperature is raised, and the indoor temperature is raised to a desired temperature (warming the indoor space).

The liquid phase heat medium obtained by condensing in the indoor heat exchanger 21 is discharged to the outside of the indoor heat exchanger 21, but in the heat exchanger switching valve near the geothermal heat exchanger 26. When the valves 65, 66, 68 are opened and the valve 67 is closed, the heat medium exiting the indoor heat exchanger 21 passes through the valves 65, 66, the auxiliary expansion valve 28, and the heat medium flow path k. Then, it will be distributed to the geothermal heat exchanger 26.

In the underground heat exchanger 26, the heat exchange medium introduced by being pressurized by a pump (not shown) and the heat medium exchange heat, and the liquid phase heat medium heated by this heat exchange is used. The temperature rises, and part of it evaporates and changes to the gas phase. On the other hand, the heat exchange medium is cooled by the heat exchange in the geothermal heat exchanger 26, and heads for the geothermal heat exchange unit 50 in a state where the temperature is lowered. Then, the heat exchange medium absorbs heat from the ground by the geothermal heat exchange unit 50 to raise the temperature, and then returns to the geothermal heat exchanger 26 again. The circulation of the heat exchange medium between the geothermal heat exchanger 26 and the geothermal heat exchanger 50 will be repeated as long as the heat exchange in the geothermal heat exchanger 26 is continued.

The heat medium heated by the geothermal heat exchanger 26 exits the geothermal heat exchanger 26, passes through the heat medium flow path l and the valve 68, and reaches the expansion valve 24.
The heat medium expands at the expansion valve 24, and the pressure and temperature are lowered. Then, the heat medium whose pressure and temperature are lowered by the expansion valve 24 is discharged to the outside of the expansion valve 24 and reaches the outdoor heat exchanger 22.

As an evaporator, the outdoor heat exchanger 22 exchanges heat between the outdoor air introduced by being blown by a fan (not shown) and a heat medium. The heat medium that is heated by heat exchange in the outdoor heat exchanger 22 and evaporates as the temperature rises to become a gas phase goes out of the outdoor heat exchanger 22 and passes through the heat medium flow path h. It reaches the flow path switching valve 25, and further flows from the flow path switching valve 25 to the compressor 23 via the heat medium flow path g. On the other hand, the outdoor air is cooled by the heat exchange in the outdoor heat exchanger 22, and is discharged into the outside air in a state where the temperature is lowered.

The heat medium of the high temperature gas phase that has left the outdoor heat exchanger 22 and reached the compressor 23 is pressurized by the compressor 23. The heat medium of the pressurized gas phase is in a state of increasing pressure and temperature. Then, the heat medium of the gas phase that has exited the compressor 23 travels toward the indoor heat exchanger 21 via the flow path switching valve 25 and the bypass switching valve 77.
After that, the heat medium returns to the inside of the indoor heat exchanger 21, and the heating is continuously executed by repeating each process after the heat exchange in the indoor heat exchanger 21 in the same manner as described above.

(When defrosting is performed using the heat source as geothermal heat)
During such a heating operation, if the outdoor temperature is low, frost may occur on the outer surface portion that exchanges heat with the air of the outdoor heat exchanger 22. The defrosting operation state corresponding to such frost formation will be described.

When frost formation is detected during heating and defrosting is performed, the heating operation is temporarily stopped and the state shifts to the defrosting operation state. In order to perform defrosting, as shown in FIG. 13, the valve 76 of the bypass switching valve is opened, the valve 77 is closed, the bypass flow path 27 communicates with the heat medium flow path g, and the bypass flow path 27 is opened. The heat medium that came out is switched to a state in which it flows through the compressor 23, the valves 66 and 68 of the heat exchanger switching valves are opened, the valves 65 and 67 are closed, and the bypass flow path 27 is the geothermal heat exchanger 26. It switches to a state of communicating with the expansion valve 24 and the outdoor heat exchanger 22 through. The flow path switching valve 25 is in the first flow path connection state, and the heat medium flow path g and the heat medium flow path j are communicated with each other, and the heat medium flow path h and the heat medium flow path i are communicated with each other on the indoor side. The heat exchanger 21 and the compressor 23 inlet are communicated with each other, and the outdoor heat exchanger 22 and the compressor 23 outlet are communicated with each other.

When the defrosting operation is executed, in the underground heat exchanger 26, the heat exchange medium introduced by being pressurized by a pump (not shown) and the heat medium exchange heat, and the heat is heated by this heat exchange. The heat medium of the liquid phase heats up and evaporates to change into a gas phase. On the other hand, the heat exchange medium is cooled by the heat exchange in the geothermal heat exchanger 26, and heads for the geothermal heat exchange unit 50 in a state where the temperature is lowered. Then, the heat exchange medium absorbs heat from the ground by the geothermal heat exchange unit 50 to raise the temperature, and then returns to the geothermal heat exchanger 26 again. The circulation of the heat exchange medium between the geothermal heat exchanger 26 and the geothermal heat exchanger 50 is repeated as long as the heat exchange in the geothermal heat exchanger 26 is continued.

The gas phase heat medium obtained by evaporating in the geothermal heat exchanger 26 passes through the heat medium flow path k, the auxiliary expansion valve 28, and the valve 66 after leaving the geothermal heat exchanger 26. And circulates in the bypass flow path 27.
On the other hand, since the other end of the bypass flow path 27 communicates with the flow path switching valve 25, the heat medium of the gas phase that has passed through the bypass flow path 27 through the valve 76 in the open state flows through the flow path. It goes to the compressor 23 via the switching valve 25.

The heat medium of the high temperature gas phase that has reached the compressor 23 is pressurized by the compressor 23, and the pressure and temperature are increased. Then, the heat medium of the gas phase exiting the compressor 23 is introduced into the outdoor heat exchanger 22 via the heat medium flow path i, the flow path switching valve 25, and the heat medium flow path h.

The outdoor heat exchanger 22 exchanges heat between the outdoor air introduced by being blown by a fan (not shown) and the heat medium of the gas phase as a condenser. The heat medium of the gas phase cooled by this heat exchange lowers its temperature and condenses into a liquid phase. On the other hand, since the outdoor air is heated by the heat exchange in the outdoor heat exchanger 22 and tries to exit the outdoor heat exchanger with the temperature raised, the frosted portion on the surface of the outdoor heat exchanger 22 is present. , It is warmed by contact with the air that raised this temperature. In the frosted portion that is warmed in this way, the frost finally melts and becomes a defrosted state. The air after warming the frosted portion is discharged into the outside air.

The heat medium whose temperature has been lowered by the outdoor heat exchanger 22 is discharged to the outside of the outdoor heat exchanger 22 and reaches the expansion valve 24. In this expansion valve 24, the heat medium expands to reduce the pressure and temperature, and then exits the expansion valve 24. Among the heat exchanger switching valves in the vicinity of the geothermal heat exchanger 26, , Valves 66 and 68 are opened and valves 65 and 67 are closed, so that the heat medium exiting the expansion valve 24 passes through the heat medium flow path l and the valve 68 to the geothermal heat exchanger 26. It will move toward.

After that, the heat medium returns to the inside of the geothermal heat exchanger 26, and each process after the heat exchange in the geothermal heat exchanger 26 is repeated in the same manner as described above to continuously execute defrosting.
When the frost is melted at all the frosted points in the outdoor heat exchanger 22 and the defrosting is completed, the defrosting operation state can be returned to the heating operation state.

In addition, in response to the case where geothermal heat is used as the heat source during heating as described above, heat is absorbed from the outdoor air during times when heating operation is not required, such as at night or when there are no people in the room. It is also possible to execute the operation as a cycle of releasing the heat to the ground, and to positively recover the underground temperature lowered by the heat absorption accompanying the heating operation and store the heat in the ground.

In order to perform the operation for recovering the underground temperature or the like, as shown in FIG. 14, the valve 76 of the bypass switching valve is opened, the valve 77 is closed, and the bypass flow path 27 is the heat medium flow path j. The heat exchanger is switched to a state in which the heat medium flows between the bypass flow path 27 and the flow path switching valve 25, and the valves 66 and 68 of the heat exchanger switching valve are opened and the valves 65 and 67 are closed. , The bypass flow path 27 is switched to a state in which it communicates with the expansion valve 24 and the outdoor heat exchanger 22 through the geothermal heat exchanger 26. The flow path switching valve 25 is in a second flow path connection state, and the heat medium flow path g and the heat medium flow path h are communicated with each other, and the heat medium flow path i and the heat medium flow path j are communicated with each other to cause a bypass flow. The road 27 and the outlet of the compressor 23 are communicated with each other, and the outdoor heat exchanger 22 and the inlet of the compressor 23 are communicated with each other.

When the operation is executed, in the geothermal heat exchanger 26, the heat exchange medium introduced by being pressurized by a pump (not shown) and the heat medium exchange heat, and the air cooled by this heat exchange is exchanged. The heat medium of the phase lowers the temperature, and part of it condenses and changes to a liquid phase. On the other hand, the heat exchange medium is heated by the heat exchange in the geothermal heat exchanger 26, and heads for the geothermal heat exchange unit 50 in a state where the temperature is raised. Then, the heat exchange medium releases heat into the ground by the geothermal heat exchange unit 50 to lower the temperature, and then returns to the geothermal heat exchanger 26 again. The circulation of the heat exchange medium between the geothermal heat exchanger 26 and the geothermal heat exchange unit 50 is repeated for the duration of the operation, and the heat exchange medium releases heat into the ground. The temperature in the ground can be raised.

The heat medium whose temperature has been lowered by the geothermal heat exchanger 26 exits the geothermal heat exchanger 26, passes through the heat medium flow path l and the valve 68, and reaches the expansion valve 24. The heat medium expands with the expansion valve 24 to reduce the pressure and temperature, then exits the expansion valve 24 and reaches the outdoor heat exchanger 22. The outdoor heat exchanger 22 exchanges heat between the outdoor air introduced by being blown by a fan (not shown) and the heat medium. The heat medium that is heated by heat exchange in the outdoor heat exchanger 22 and evaporates as the temperature rises to become a vapor phase goes out of the outdoor heat exchanger 22 and goes out of the outdoor heat exchanger 22 to the heat medium flow paths h, g. Then, it goes to the compressor 23. On the other hand, the outdoor air is cooled by the heat exchange in the outdoor heat exchanger 22, and is discharged into the outside air in a state where the temperature is lowered.

The heat medium of the high temperature gas phase that has left the outdoor heat exchanger 22 and reached the compressor 23 is pressurized by the compressor 23, and the pressure and temperature are increased. Then, the heat medium of the gas phase leaving the compressor 23 reaches the bypass flow path 27 via the flow path switching valve 25, and further passes through the valve 66, the auxiliary expansion valve 28, and the heat medium flow path k to be ground. It will proceed toward the medium heat exchanger 26.

After that, the heat medium returns to the inside of the geothermal heat exchanger 26, and each process after the heat exchange in the geothermal heat exchanger 26 is repeated in the same manner as described above.
When the underground temperature rises to an appropriate temperature or the time zone for heating the indoor space is reached, the operation related to the recovery of the underground temperature is stopped and the operation is shifted to the heating operation as necessary. ..

As described above, in the heat pump system according to the present embodiment, the indoor heat exchanger 21 arranged indoors, the outdoor heat exchanger 22 arranged outdoors, the compressor 23, the expansion valve 24, and the expansion valve 24, and the outdoor heat exchanger 22 arranged outdoors. It is possible to switch the state of communication between the geothermal heat exchanger 26 and the bypass flow path 27 via each switching valve to the heat medium flow path between the flow path switching valve 25 and the location that appears outdoors. Therefore, a heat medium circuit for using the geothermal heat exchanger 26 is reasonably and appropriately incorporated between the indoor unit portion and the outdoor unit portion of the system to heat the geothermal heat exchanger 26. A state in which the medium can be circulated and the geothermal heat can be used as a heat source can be obtained without changing the configuration of the existing indoor unit part and the outdoor unit part, and the component part that enables the geothermal heat can be used at low cost. It can be installed, and a system that uses geothermal heat can be introduced more easily.

Further, a bypass flow path 27 is provided to allow the underground heat exchanger 26 to communicate with the inlet side of the compressor 23 through the flow path switching valve 25, so that the heat medium does not pass through the indoor heat exchanger 21 and bypass flows. By creating a state in which the compressor 23, the outdoor heat exchanger 22, and the underground heat exchanger 26 circulate through the path 27, the outdoor heat exchanger 22 responds to frost formation. , The underground heat taken in by the underground heat exchanger 26 is introduced into the outdoor heat exchanger 22 to enable defrosting by heat dissipation in the outdoor heat exchanger 22, or the outdoor heat exchanger 22 is used to remove frost. It absorbs heat from the air and releases the heat to the ground through the underground heat exchanger 26 to recover the lowered underground temperature, store heat in the ground, or absorb heat from the ground. The extracted heat is transferred to the outdoor heat exchanger 22 through the underground heat exchanger 26, and the heat is released to the outdoor air to recover the elevated underground temperature and store cold heat in the ground. It can improve the efficiency of heating and cooling by making the underground heat available appropriately.

(Third Embodiment of the present invention)
A third embodiment of the present invention will be described with reference to FIGS. 15 to 18. In this embodiment, an example applied to a so-called multi air conditioner type air conditioner including a plurality of indoor units will be described.

In each of the drawings, the heat pump system 3 according to the present embodiment has the indoor heat exchangers 31 and 32, the outdoor heat exchangers 33, the compressor 34, and the expansion valves 35a and 35b, as in the first embodiment. , 35c, 35d, flow path switching valves 36, 37, underground heat exchanger 38, and heat exchanger switching valves 81, 82, except that the indoor heat exchanger 31, A plurality of 32 are arranged, and expansion valves 35a, 35b, 35c are provided at one of the heat medium inflow / outlets of the indoor heat exchangers 31, 32, the outdoor heat exchanger 33, and the underground heat exchanger 38, respectively. , 35d are connected, and these expansion valves 35a, 35b, 35c, 35d are connected to a common heat medium flow path, and the other heat medium inflow port in each indoor side heat exchangers 31 and 32 is connected to the compressor 34. Cooling / heating switching valves 91, 92, 93, 94, which enable switching between a state in which communication is performed and a state in which communication is not performed, are arranged on the inlet side and the outlet side, respectively. The other heat medium inflow port of the outer heat exchanger 33 can be switched between a state in which the other heat medium inflow port communicates with the inlet side and the outlet side of the compressor 34 and a state in which the other heat medium inflow port does not communicate with each other. , 82 is configured to enable switching between a state in which the other heat medium inflow outlet in the underground heat exchanger 38 communicates with the inlet side and the outlet side of the compressor 34 and a state in which the other heat medium inflow outlet does not communicate with each other. Have.

Regarding the configurations of the indoor heat exchangers 31 and 32, the outdoor heat exchanger 33, the compressor 34, the expansion valves 35a, 35b, 35c, 35d, and the geothermal heat exchanger 38, the above-mentioned first. It is the same as that of the first embodiment, and detailed description thereof will be omitted.

In the indoor heat exchanger 31, one heat medium inflow outlet is connected to the expansion valve 35a and communicates with the common heat medium flow path m via the expansion valve 35a, and the other heat medium inflow outlet is used for cooling / heating switching. It is connected to the valves 91 and 92. The other heat medium inflow outlet of the indoor heat exchanger 31 can communicate with the compressor 34 outlet side via the cooling / heating switching valve 91, and communicates with the compressor 34 inlet side via the cooling / heating switching valve 92. It is possible to communicate.

The cooling / heating switching valves 91 and 92 have a cooling connection state in which the valve 91 is closed and the valve 92 is opened so that the heat medium exiting the indoor heat exchanger 31 faces the compressor 34, and the valve 91 is opened. , The valve 92 is closed, and it is possible to switch between the heating connection state in which the heat medium exiting the compressor 34 faces the indoor heat exchanger 31. When the indoor heat exchanger 31 is not used for either cooling or heating, both the cooling / heating switching valves 91 and 92 are closed so that the heat medium does not flow into the indoor heat exchanger 31. It is also possible to suppress heat loss.

In the indoor heat exchanger 32, one heat medium inflow outlet is connected to the expansion valve 35b and communicates with the common heat medium flow path m via the expansion valve 35b, and the other heat medium inflow outlet is used for cooling / heating switching. It is connected to valves 93 and 94. The other heat medium inflow outlet of the indoor heat exchanger 32 can communicate with the compressor 34 outlet side via the cooling / heating switching valve 93, and communicates with the compressor 34 inlet side via the cooling / heating switching valve 94. It is possible to communicate.

The cooling / heating switching valves 93 and 94 have a cooling connection state in which the valve 93 is closed and the valve 94 is opened so that the heat medium exiting the indoor heat exchanger 32 faces the compressor 34 and the valve 93 is opened. , The valve 94 is closed, and it is possible to switch between the heating connection state in which the heat medium exiting the compressor 34 faces the indoor heat exchanger 32. When the indoor heat exchanger 32 is not used for either cooling or heating, both the cooling / heating switching valves 93 and 94 are closed so that the heat medium does not flow into the indoor heat exchanger 32. It is also possible to suppress heat loss.

In the outdoor heat exchanger 33, one heat medium inflow port is connected to the expansion valve 35c and communicates with the common heat medium flow path m via the expansion valve 35b, and the other heat medium inflow port is switched. It is connected to the valves 36 and 37. The other heat medium inflow outlet of the outdoor heat exchanger 33 can communicate with the compressor 34 outlet side via the flow path switching valve 36, and the compressor 34 inlet via the flow path switching valve 37. It is possible to communicate with the side.

The flow path switching valves 36 and 37 have a first flow path connection state in which the valve 36 is opened and the valve 37 is closed so that the other heat medium inflow outlet of the outdoor heat exchanger 33 communicates with the compressor 34 outlet. , The valve 36 is closed, the valve 37 is opened, and the second flow path connection state in which the other heat medium inflow outlet of the outdoor heat exchanger 33 is communicated with the compressor 34 inlet, and the valves 36 and 37 are both closed. As a result, it is possible to switch between a third flow path connection state in which the outdoor heat exchanger 33 is not communicated with the compressor 34 and the heat medium is not circulated through the outdoor heat exchanger 33.

In the outdoor heat exchanger 33, when one of the indoor heat exchangers 31 and 32 is in the cooling operation and the other is in the heating operation, the cooling load becomes larger than the heating load, or the indoor heat exchangers 31 and 32 are used. When both are in the cooling operation state, the flow path switching valves 36 and 37 are set as the first flow path connection state in response to the cooling load and operate as a condenser (see FIG. 16). Further, when one of the indoor heat exchangers 31 and 32 is in the cooling operation and the other is in the heating operation, the heating load becomes larger than the cooling load, or the indoor heat exchangers 31 and 32 are both in the heating operation state. In this case, the flow path switching valves 36 and 37 are connected to the second flow path and operate as an evaporator in response to the heating load (see FIG. 15).

In addition, the outdoor heat exchanger 33 is used as a heat medium condenser in response to the cooling or heating load of the indoor heat exchangers 31 and 32 by exchanging heat of the heat medium in the geothermal heat exchanger 38. Alternatively, when it is not operated as an evaporator, the flow path switching valves 36 and 37 may be connected to the third flow path to prevent the heat medium from flowing through the outdoor heat exchanger 33.

In the geothermal heat exchanger 38, one heat medium inflow port is connected to the expansion valve 35d and communicates with the common heat medium flow path m via the expansion valve 35d, and the other heat medium inflow port is heat exchanged. It is connected to the device switching valves 81 and 82. The other heat medium inflow outlet of the geothermal heat exchanger 38 is made communicable with the outlet side of the compressor 34 via the heat exchanger switching valve 81, and is compressed via the heat exchanger switching valve 82. It is possible to communicate with the entrance side of the machine 34.

The heat exchanger switching valves 81 and 82 have a fourth flow path connection state in which the heat medium exiting the compressor 34 is directed to the geothermal heat exchanger 38 with the valve 81 opened and the valve 82 closed, and the valves. With 81 closed and valve 82 open, the heat medium exiting the underground heat exchanger 38 is connected to the fifth flow path toward the compressor 34, and both valves 81 and 82 are closed to geothermal heat. It is possible to switch between the sixth flow path connection state in which the heat exchanger 38 is not communicated with the compressor 34 and the heat medium is not circulated through the geothermal heat exchanger 38.

In the geothermal heat exchanger 38, when the flow path switching valves 36 and 37 are connected to the outdoor heat exchanger 33 in the first flow path and the outdoor heat exchanger 33 operates as a condenser. The heat exchanger switching valves 81 and 82 are connected to the fourth flow path and operate as a condenser (see FIG. 16). Further, when the flow path switching valves 36 and 37 are connected to the outdoor heat exchanger 33 in the second flow path connection state and the outdoor heat exchanger 33 operates as an evaporator, the heat exchanger is switched. The valves 81 and 82 are connected to the fifth flow path and operate as an evaporator.

In addition, the geothermal heat exchanger 38 is used as a heat medium condenser in response to the cooling or heating load of the indoor heat exchangers 31 and 32 by heat exchange of the heat medium in the outdoor heat exchanger 33. Alternatively, when not operating as an evaporator, the heat exchanger switching valves 81 and 82 may be connected to the sixth flow path to prevent the heat medium from flowing through the geothermal heat exchanger 38 (Fig.). 15).

Further, the cooling / heating switching valves 91, 92, 93, and 94 are all closed to prevent the heat medium from flowing into the indoor heat exchangers 31 and 32, and the flow path is switched with respect to the outdoor heat exchanger 33. With the valves 36 and 37 in the first flow path connection state, the outdoor heat exchanger 33 operates as a condenser, and together, the heat exchanger switching valves 81 and 82 are in the fifth flow path connection state. As a result, a flow path connection state (see FIG. 17) for operating the geothermal heat exchanger 38 as an evaporator can also be selected.

In this state, the heat medium flows from the compressor 34 into the outdoor heat exchanger 33 via the flow path switching valve 36 opened as the first flow path connection state, and the expansion valve from the outdoor heat exchanger 33. The heat medium exiting the geothermal heat exchanger 38 goes to the geothermal heat exchanger 38 via the 35c, the common heat medium flow path m, and the expansion valve 35d, and the heat medium exiting the geothermal heat exchanger 38 passes through the heat exchanger switching valve 82 to the compressor 23. In a state where a circulation path is generated, that is, the heat medium is heated by the geothermal heat in the geothermal heat exchanger 38, the heat medium is heated to a high pressure by the compressor 34, and then the outdoor heat exchanger 33 is generated. The heat is released from the heat medium to obtain a defrosting connection state in which defrosting can be performed by the outdoor heat exchanger 33.

Expansion valves 35a, 35b, 35c, and 35d are connected to one of the heat medium inflow ports of the indoor heat exchangers 31, 32, the outdoor heat exchanger 33, and the geothermal heat exchanger 38, respectively. The expansion valves 35a, 35b, 35c, and 35d are all connected to the common heat medium flow path m. Therefore, the indoor heat exchangers 31 and 32, the outdoor heat exchanger 33, and the geothermal heat exchanger 38 are in a state of communicating with each other via the expansion valve, and the heat medium is transmitted between the heat exchangers. It can be distributed.

Next, the operating state of the heat pump system according to the present embodiment will be described.
First, a state in which the heat pump system is operated to cool and heat the indoor space will be described.

When cooling or heating, the state where the heat source is only outdoor air heat, only underground heat, or both air heat and underground heat is switched according to the indoor, outdoor, and underground conditions. be able to.
For example, at the start of cooling or heating operation, the load on the indoor unit side of the air conditioner becomes large, so it is preferable to use both outdoor air heat and geothermal heat as the heat source. Then, when the room temperature reaches a desired temperature and shifts to a stable state, and the air conditioner becomes a low-load operation state in which on / off repetition and output are suppressed, only geothermal heat is used as a heat source. If the switching is performed, an efficient operating state can be maintained, which is preferable.

In addition, when the temperature of the heat medium is different from the outdoor air temperature, the cooling or heating operation is performed mainly using the outdoor air heat and the geothermal heat as heat sources, while the heat medium temperature is the outdoor air temperature. If it is expected that an excessive heat load is applied to the ground, such as when the value is close to, and the temperature in the ground changes significantly, the system shifts to an operating state in which only outdoor air heat is used as the heat source. It is preferable to stop the heat exchange between the medium heat heat exchanger 38 and the ground through the heat exchange medium so that the ground temperature can be recovered.

(When the heat source is only air heat)
When cooling or heating each indoor space, when only outdoor air heat is used as a heat source, that is, when only outdoor heat exchanger 33 is used as an outdoor condenser or evaporator, FIG. As shown in the above, both the valves 81 and 82 of the heat exchanger switching valves are closed to prevent the heat medium from flowing to the geothermal heat exchanger 38, while the outdoor heat exchanger 33 is the expansion valve 35c. And the indoor heat exchangers 31 and 32 are communicated with each other through the flow path switching valves 36 and 37. Further, the flow path switching valves 36 and 37 are set to the first flow path connection state or the second flow path connection state so that the outdoor heat exchanger 33 and the compressor 34 outlet or inlet are communicated with each other.

For example, when one indoor heat exchanger 31 is used for cooling and the other indoor heat exchanger 32 is used for heating and the heating load exceeds the cooling load, when the heat pump system is operated, the indoor side As an evaporator, the heat exchanger 31 exchanges heat between the indoor air introduced by being blown by a fan (not shown) and the heat medium of the liquid phase. The heat medium that is heated by heat exchange in the indoor heat exchanger 31 and evaporates as the temperature rises to become a vapor phase exits from the other heat medium inflow outlet of the indoor heat exchanger 31 to cool and heat. It goes to the compressor 34 via the switching valve 92. On the other hand, the indoor air is cooled by the heat exchange in the indoor heat exchanger 31 and released into the indoor space in a state where the temperature is lowered, and the indoor temperature is lowered to a desired temperature (cooling the indoor space).

Further, in another indoor space, the indoor heat exchanger 32 exchanges heat between the indoor air introduced by being blown by a fan (not shown) as a condenser and the heat medium of the gas phase. The heat medium of the gas phase cooled by this heat exchange condenses and changes into a liquid phase. On the other hand, the indoor air is heated by the heat exchange in the indoor heat exchanger 32 and released into the indoor space in a state where the temperature is raised, and the indoor temperature is raised to a desired temperature (warming the indoor space).

The liquid phase heat medium obtained by condensing in the indoor heat exchanger 32 is discharged from one of the heat medium inflow outlets of the indoor heat exchanger 32 and reaches the expansion valve 35b. The heat medium of the liquid phase is expanded by the expansion valve 35b, and the pressure and temperature are reduced.

The liquid phase heat medium whose pressure and temperature are lowered by the expansion valve 35b exits the expansion valve 35b, passes through the common heat medium flow path m, and a part of the heat medium passes through the expansion valve 35c to the outdoor heat exchanger. It reaches one heat medium inflow port of 33, and the other part reaches one heat medium inflow port of the indoor heat exchanger 31 via the expansion valve 35a.

The outdoor heat exchanger 33, as an evaporator, exchanges heat between the outdoor air introduced by being blown by a fan (not shown) and the heat medium of the liquid phase. The heat medium that is heated by heat exchange in the outdoor heat exchanger 33 and evaporates as the temperature rises to become a vapor phase goes out of the outdoor heat exchanger 33 and presses the flow path switching valve 37. After that, it goes to the compressor 34. On the other hand, the outdoor air is cooled by the heat exchange in the outdoor heat exchanger 33, and is discharged into the outside air in a state where the temperature is lowered.

The heat medium of the high temperature gas phase that has left the indoor heat exchanger 31 and the outdoor heat exchanger 33 and reached the compressor 34 is pressurized by the compressor 34. The heat medium of the pressurized gas phase is in a state of increasing pressure and temperature. Then, the heat medium of the gas phase exiting the compressor 34 goes through the cooling / heating switching valve 93 toward the other heat medium inflow outlet of the indoor heat exchanger 32.

After that, the heat medium returns to the inside of the indoor side heat exchanger 32, reaches the indoor side heat exchanger 31 and the outdoor side heat exchanger 33, respectively, and further reaches the compressor 34 in the same manner as described above. By repeating the process, heating by the indoor heat exchanger 32 and cooling by the indoor heat exchanger 31 are continuously executed.

(When the heat source is air heat and geothermal heat)
When outdoor air heat and geothermal heat are used as heat sources when cooling or heating the indoor space, that is, the outdoor heat exchanger 33 and the geothermal heat exchanger as the outdoor condenser or evaporator. When 38 is used together, as shown in FIG. 16, the outdoor heat exchanger 33 can communicate with the indoor heat exchangers 31 and 32 through the expansion valve 35c and the flow path switching valves 36 and 37. Similarly to the above, the geothermal heat exchanger 38 is also switched to a state in which it can communicate with the indoor heat exchangers 31 and 32 through the expansion valve 35d and the heat exchanger switching valves 81 and 82.

For example, when one indoor heat exchanger 31 is used for cooling and the other indoor heat exchanger 32 is used for heating and the cooling load exceeds the heating load, when the heat pump system is operated, the indoor side As an evaporator, the heat exchanger 31 exchanges heat between the indoor air introduced by being blown by a fan (not shown) and the heat medium of the liquid phase. The heat medium that is heated by heat exchange in the indoor heat exchanger 31 and evaporates as the temperature rises to become a vapor phase exits from the other heat medium inflow outlet of the indoor heat exchanger 31 to cool and heat. It goes to the compressor 34 via the switching valve 92. On the other hand, the indoor air is cooled by the heat exchange in the indoor heat exchanger 31 and released into the indoor space in a state where the temperature is lowered, and the indoor temperature is lowered to a desired temperature (cooling the indoor space).

Further, in another indoor space, the indoor heat exchanger 32 exchanges heat between the indoor air introduced by being blown by a fan (not shown) as a condenser and the heat medium of the gas phase. The heat medium of the gas phase cooled by this heat exchange condenses and changes into a liquid phase. On the other hand, the indoor air is heated by the heat exchange in the indoor heat exchanger 32 and released into the indoor space in a state where the temperature is raised, and the indoor temperature is raised to a desired temperature (warming the indoor space).

The liquid phase heat medium obtained by condensing in the indoor heat exchanger 32 is discharged from one of the heat medium inflow outlets of the indoor heat exchanger 32 and reaches the expansion valve 35b. The heat medium of the liquid phase is expanded by the expansion valve 35b, and the pressure and temperature are reduced.

The liquid phase heat medium whose pressure and temperature have been lowered by the expansion valve 35b exits the expansion valve 35b, passes through the common heat medium flow path m, passes through the expansion valve 35a, and further lowers the pressure and temperature. , Reach one of the heat medium inflow outlets of the indoor heat exchanger 31.

The heat medium of the high temperature gas phase that has left the indoor heat exchanger 31 and reached the compressor 34 is pressurized by the compressor 34. The heat medium of the pressurized gas phase is in a state of increasing pressure and temperature. Then, a part of the heat medium of the gas phase that has left the compressor 34 is introduced into the outdoor heat exchanger 22 via the flow path switching valve 36, and another part of the heat exchanger switching valve 81 is introduced. After that, it is introduced into the geothermal heat exchanger 38. Further, the rest of the heat medium goes through the cooling / heating switching valve 93 toward the other heat medium inflow port of the indoor heat exchanger 32.

The outdoor heat exchanger 33, as a condenser, exchanges heat between the outdoor air introduced by being blown by a fan (not shown) and the heat medium of the gas phase. The heat medium of the gas phase cooled by this heat exchange lowers its temperature, and a part of it condenses and changes into a liquid phase. On the other hand, the outdoor air is heated by the heat exchange in the outdoor heat exchanger 33, and is discharged into the outside air in a state where the temperature is raised.

The heat medium whose temperature has been lowered by the outdoor heat exchanger 33 is discharged to the outside of the outdoor heat exchanger 33 and reaches the expansion valve 35c. In this expansion valve 35c, the heat medium expands to reduce the pressure and temperature, then exits the expansion valve 35c, passes through the common heat medium flow path m, passes through the expansion valve 35a, and further increases the pressure. After lowering the temperature, the process proceeds toward one of the heat medium inflow outlets of the indoor heat exchanger 31.

In addition, also in the geothermal heat exchanger 38, the heat exchange medium introduced by being pressurized by a pump (not shown) and the heat medium exchange heat, and the gas phase cooled by this heat exchange The heat medium will condense and change into a liquid phase. On the other hand, the heat exchange medium is heated by the heat exchange in the geothermal heat exchanger 38, and heads for the geothermal heat exchange unit 50 in a state where the temperature is raised. Then, the heat exchange medium releases heat into the ground at the geothermal heat exchange unit 50 to lower the temperature, and then returns to the geothermal heat exchanger 38 again. The circulation of the heat exchange medium between the geothermal heat exchanger 38 and the geothermal heat exchanger 50 is repeated as long as the heat exchange in the geothermal heat exchanger 38 is continued.

The liquid phase heat medium obtained by condensing in the geothermal heat exchanger 38 is discharged from one of the heat medium inflow outlets of the geothermal heat exchanger 38 and reaches the expansion valve 35d. The heat medium of the liquid phase is expanded by the expansion valve 35d, and the pressure and temperature are reduced.

The liquid phase heat medium whose pressure and temperature are lowered by the expansion valve 35d exits the expansion valve 35d, passes through the common heat medium flow path m, passes through the expansion valve 35a, and further lowers the pressure and temperature. , It will proceed toward one of the heat medium inflow outlets of the indoor heat exchanger 31.

After that, the heat medium returns to the inside of the indoor heat exchanger 31, and similarly from the indoor heat exchanger 31 to the compressor 34, and further from the compressor 34 to the indoor heat exchanger 32 and the outdoor heat exchanger 33. , And each process of reaching the geothermal heat exchanger 38 is repeated, and heating by the indoor heat exchanger 32 and cooling by the indoor heat exchanger 31 are continuously executed.

(When defrosting is performed using the heat source as geothermal heat)
When the heating load in the indoor heat exchangers 31 and 32 is high and the outdoor heat exchanger 33 is operated as an evaporator and the outdoor temperature is low, heat is exchanged with the air in the outdoor heat exchanger 33. Frost formation may occur on the outer surface. The defrosting operation state corresponding to such frost formation will be described.

When frost formation is detected in the outdoor heat exchanger 33 and defrosting is performed, the heat pump is temporarily stopped to shift to the defrosting operation state. In order to defrost, as shown in FIG. 17, the cooling / heating switching valves 91, 92, 93, 94 are all closed, and the indoor heat exchangers 31 and 32 are switched to a state in which the heat medium does not flow. , The flow path switching valves 36 and 37 are connected to the first flow path, that is, the valve 36 is opened and the valve 37 is closed, and the other heat medium inflow outlet of the outdoor heat exchanger 33 is connected to the compressor 34 outlet. The state of communication is switched so that the outdoor heat exchanger 33 operates as a condenser. Further, the heat exchanger switching valves 81 and 82 are connected to the fifth flow path, that is, the valve 81 is closed and the valve 82 is opened, and the other heat medium inflow outlet of the geothermal heat exchanger 38 is compressed. The state is switched to communicate with the 34 inlet so that the geothermal heat exchanger 38 operates as an evaporator.

When the defrosting operation is executed, in the underground heat exchanger 38, the heat exchange medium introduced by being pressurized by a pump (not shown) and the heat medium exchange heat, and the heat is heated by this heat exchange. The heat medium of the liquid phase heats up and evaporates to change into a gas phase. On the other hand, the heat exchange medium is cooled by the heat exchange in the geothermal heat exchanger 38, and heads for the geothermal heat exchange unit 50 in a state where the temperature is lowered. Then, the heat exchange medium absorbs heat from the ground by the geothermal heat exchange unit 50 to raise the temperature, and then returns to the geothermal heat exchanger 38 again. The circulation of the heat exchange medium between the geothermal heat exchanger 38 and the geothermal heat exchanger 50 is repeated as long as the heat exchange in the geothermal heat exchanger 38 is continued.

The gas phase heat medium obtained by evaporating in the geothermal heat exchanger 38 is compressed through the heat exchanger switching valve 82 and the heat medium flow path n after leaving the geothermal heat exchanger 38. Head to machine 34.
The heat medium of the high temperature gas phase that has reached the compressor 34 is pressurized by the compressor 34, and the pressure and temperature are increased. Then, the heat medium of the gas phase exiting the compressor 34 is introduced into the outdoor heat exchanger 33 via the heat medium flow path o and the flow path switching valve 36.

The outdoor heat exchanger 33, as a condenser, exchanges heat between the outdoor air introduced by being blown by a fan (not shown) and the heat medium of the gas phase. The heat medium of the gas phase cooled by this heat exchange lowers its temperature and condenses into a liquid phase. On the other hand, since the outdoor air is heated by the heat exchange in the outdoor heat exchanger 33 and tries to exit the outdoor heat exchanger in a state where the temperature is raised, the frosted portion on the surface of the outdoor heat exchanger 33 is present. , It is warmed by contact with the air that raised this temperature. In the frosted portion that is warmed in this way, the frost finally melts and becomes a defrosted state. The air after warming the frosted portion is discharged into the outside air.

The heat medium condensed by the outdoor heat exchanger 33 is discharged to the outside of the outdoor heat exchanger 33 and reaches the expansion valve 35c. With this expansion valve 35c, the heat medium expands and the pressure and temperature are reduced. Then, the heat medium exiting the expansion valve 35c passes through the common heat medium flow path m, further lowers the pressure and temperature through the expansion valve 35d, and then flows into one of the heat mediums of the geothermal heat exchanger 38. You will proceed toward the exit.

After that, the heat medium returns to the inside of the geothermal heat exchanger 38, and each process after the heat exchange in the geothermal heat exchanger 38 is repeated in the same manner as described above to continuously execute defrosting.
When the frost has melted at all the frosted points in the outdoor heat exchanger 33 and the defrosting is completed, the operation state in which the previous outdoor heat exchanger 33 is used as an evaporator can be returned from the defrosting operation state.

In response to the case where geothermal heat is used as the heat source as described above, heat is taken from the ground and the heat is removed during times when cooling or heating operation is not required, such as at night or when there are no people in the room. The operation is executed as a cycle of releasing to the outdoor air, and the underground heat exchanger 38 is operated as a condenser. The recovery of the underground temperature increased by the heat release accompanying the operation and the storage of cold heat in the ground are positively performed. It can also be planned.

The operation for recovering the underground temperature or the like may be performed in the same manner as in the defrosting operation state, and as shown in FIG. 17, all of the cooling / heating switching valves 91, 92, 93, 94 are closed, and the chamber The inner heat exchangers 31 and 32 are switched to a state in which the heat medium does not flow, and the flow path switching valves 36 and 37 are connected to the first flow path, that is, the valve 36 is opened and the valve 37 is closed to open the outdoor side. The other heat medium inflow outlet of the heat exchanger 33 is switched to a state of communicating with the compressor 34 outlet so that the outdoor heat exchanger 33 operates as a condenser. Further, the heat exchanger switching valves 81 and 82 are connected to the fifth flow path, that is, the valve 81 is closed and the valve 82 is opened, and the other heat medium inflow outlet of the geothermal heat exchanger 38 is compressed. The state is switched to communicate with the 34 inlet so that the geothermal heat exchanger 38 operates as an evaporator.

When the operation is executed, in the underground heat exchanger 38, the heat exchange medium introduced by being pressurized by a pump (not shown) and the heat medium exchange heat, and the liquid heated by this heat exchange. The heat medium of the phase heats up and evaporates to change into a gas phase. On the other hand, the heat exchange medium is cooled by the heat exchange in the geothermal heat exchanger 38, and heads for the geothermal heat exchange unit 50 in a state where the temperature is lowered. Then, the heat exchange medium absorbs heat from the ground by the geothermal heat exchange unit 50 to raise the temperature, and then returns to the geothermal heat exchanger 38 again. The circulation of the heat exchange medium between the geothermal heat exchanger 38 and the geothermal heat exchange unit 50 is repeated for the duration of the operation, and the heat exchange medium absorbs heat from the ground. The temperature in the ground can be lowered.

The gas phase heat medium obtained by evaporating in the geothermal heat exchanger 38 is compressed through the heat exchanger switching valve 82 and the heat medium flow path n after leaving the geothermal heat exchanger 38. Head to machine 34.
The heat medium of the high temperature gas phase that has reached the compressor 34 is pressurized by the compressor 34, and the pressure and temperature are increased. Then, the heat medium of the gas phase exiting the compressor 34 is introduced into the outdoor heat exchanger 33 via the heat medium flow path o and the flow path switching valve 36.

In the outdoor heat exchanger 33, the outdoor air introduced by being blown by a fan (not shown) exchanges heat with the heat medium of the gas phase, and the heat medium of the gas phase cooled by this heat exchange is the heat medium. It lowers the temperature and condenses into a liquid phase. On the other hand, the outdoor air is heated by the heat exchange in the outdoor heat exchanger 33, and is discharged into the outside air in a state where the temperature is raised.

The heat medium condensed by the outdoor heat exchanger 33 is discharged to the outside of the outdoor heat exchanger 33 and reaches the expansion valve 35c. With this expansion valve 35c, the heat medium expands and the pressure and temperature are reduced. Then, the heat medium exiting the expansion valve 35c passes through the common heat medium flow path m, further lowers the pressure and temperature through the expansion valve 35d, and then flows into one of the heat mediums of the geothermal heat exchanger 38. You will proceed toward the exit.

After that, the heat medium returns to the inside of the geothermal heat exchanger 38, and each process after the heat exchange in the geothermal heat exchanger 38 is repeated in the same manner as described above.
When the underground temperature drops to an appropriate temperature, or when it is time to cool or heat each indoor space, the operation related to the recovery of the underground temperature is stopped, and if necessary, the underground is stopped. Shift to cooling or heating operation using the heat exchanger 38 as a condenser.

Also, in response to the case where geothermal heat is used as the heat source, heat is absorbed from the outdoor air and the heat is used as the ground during times when cooling or heating operation is not required, such as at night or when there are no people in the room. The operation is executed as a cycle of releasing into the ground, and the underground heat exchanger 38 is operated as an evaporator. The underground temperature lowered by the heat absorption associated with the operation is recovered and the heat is stored in the ground positively. You can also do it.

In order to perform the operation for recovering the underground temperature, etc., as shown in FIG. 18, the cooling / heating switching valves 91, 92, 93, 94 are all closed, and the indoor heat exchangers 31 and 32 are closed. While switching to a state in which the heat medium does not flow, the flow path switching valves 36 and 37 are connected to the second flow path, that is, the valve 36 is closed and the valve 37 is opened to heat the other of the outdoor heat exchanger 33. The medium inflow port is switched to a state in which it communicates with the compressor 34 inlet so that the outdoor heat exchanger 33 operates as an evaporator. Further, the heat exchanger switching valves 81 and 82 are connected to the fourth flow path, that is, the valve 81 is opened and the valve 82 is closed, and the other heat medium inflow outlet of the geothermal heat exchanger 38 is compressed. Switch to a state where it communicates with the 34 outlet so that the geothermal heat exchanger 38 operates as a condenser.

When the operation is executed, in the geothermal heat exchanger 38, the heat exchange medium introduced by being pressurized by a pump (not shown) and the heat medium exchange heat, and the air cooled by this heat exchange is exchanged. The heat medium of the phase lowers the temperature, and part of it condenses and changes to a liquid phase. On the other hand, the heat exchange medium is heated by the heat exchange in the geothermal heat exchanger 38, and heads for the geothermal heat exchange unit 50 in a state where the temperature is raised. Then, the heat exchange medium releases heat into the ground at the geothermal heat exchange unit 50 to lower the temperature, and then returns to the geothermal heat exchanger 38 again. The circulation of the heat exchange medium between the geothermal heat exchanger 38 and the geothermal heat exchange unit 50 is repeated for the duration of the operation, and the heat exchange medium releases heat into the ground. The temperature in the ground can be raised.

The heat medium whose temperature has been lowered by the geothermal heat exchanger 38 reaches the expansion valve 35d after exiting the geothermal heat exchanger 26. With this expansion valve 35d, the heat medium expands and the pressure and temperature are reduced. Then, the heat medium exiting the expansion valve 35d passes through the common heat medium flow path m, further lowers the pressure and temperature through the expansion valve 35c, and then one of the heat medium inflow outlets of the outdoor heat exchanger 33. To reach.

The outdoor heat exchanger 33 exchanges heat between the outdoor air introduced by being blown by a fan (not shown) and the heat medium. The heat medium that is heated by heat exchange in the outdoor heat exchanger 33 and evaporates as the temperature rises to become a vapor phase goes out of the outdoor heat exchanger 33 and presses the flow path switching valve 37. After that, it goes to the compressor 34. On the other hand, the outdoor air is cooled by the heat exchange in the outdoor heat exchanger 33, and is discharged into the outside air in a state where the temperature is lowered.

The heat medium of the high temperature gas phase that has left the outdoor heat exchanger 33 and reached the compressor 34 is pressurized by the compressor 34, and the pressure and temperature are increased. Then, the heat medium of the gas phase that has exited the compressor 34 travels toward the geothermal heat exchanger 38 via the heat exchanger switching valve 81.

After that, the heat medium returns to the inside of the geothermal heat exchanger 38, and each process after the heat exchange in the geothermal heat exchanger 38 is repeated in the same manner as described above.
When the underground temperature rises to an appropriate temperature, or when it is time to cool or heat each indoor space, the operation related to the recovery of the underground temperature is stopped, and if necessary, the underground is stopped. Shift to cooling or heating operation using the heat exchanger 38 as an evaporator.

As described above, in the heat pump system according to the present embodiment, when a plurality of indoor heat exchangers 31 and 32 arranged are used for heat exchange related to cooling and heating, each switching valve is used. A state in which only the outdoor heat exchanger 33 is communicated with the indoor heat exchangers 31 and 32 and the compressor 34 and only air heat is used as the heat source, and the outdoor heat exchanger 33 and the underground heat exchanger 38 are used. Can be switched between a state in which air heat and underground heat are used as heat sources and a state in which only the underground heat exchanger 38 is communicated and only underground heat is used as a heat source. Even in the case of a so-called multi-air conditioner configuration using a plurality of heat exchangers, a refrigeration cycle or a heat pump cycle can be constructed efficiently by using one or both of the outdoor heat exchanger 33 and the underground heat exchanger 38 without difficulty. You can get a state where you can cool and heat. Further, by adjusting the flow path connection by each switching valve, the heat medium circulates in the compressor 34, the outdoor heat exchanger 33, and the geothermal heat exchanger 38 without passing through the indoor heat exchangers 31 and 32. A state can be generated, and when the outdoor heat exchanger 33 reaches a frosted state around the heat exchanger, the geothermal heat taken into the heat medium by the geothermal heat exchanger 38 is used as outdoor heat. Defrosting can be performed by introducing it only to the exchanger 33, and it is possible to efficiently perform defrosting by utilizing geothermal heat and avoid deterioration of heat exchange performance.

Further, in a system in which a plurality of indoor heat exchangers 31 and 32 are arranged indoors, the geothermal heat exchanger 38 provides heat exchanger switching valves 81 and 82 to the heat medium flow path appearing outdoors. Since the communication state is switched and connected via the system, a heat medium circuit for using the geothermal heat exchanger 38 is reasonably and appropriately incorporated in the outdoor part of the system, and the geothermal heat exchanger 38 is connected. A state in which the heat medium can be circulated and the geothermal heat can be used as a heat source can be obtained without changing the configuration of each of the existing indoor and outdoor devices constituting the system. It can be installed at low cost, and a system that uses geothermal heat can be introduced more easily.

In the heat pump system according to each of the first to third embodiments, the heat exchanger switching valve, the bypass switching valve, the cooling / heating switching valve, and some of the flow path switching valves (36, 37) are used. , A simple valve device that switches between the flow state and the flow stop state of the heat medium by opening and closing the valve is used, and by arranging a plurality of such valve devices in combination, the connection relationship between the multiple flow paths can be switched. However, the present invention is not limited to this, and it is possible to use a switching valve such as a three-way valve or a four-way valve as each of the switching valves, and the functions of a plurality of valves are integrated into one valve. Therefore, the number of valves installed can be reduced and the arrangement of heat medium flow paths can be simplified.

1, 2, 3 Heat pump system 11, 21, 31, 32 Indoor heat exchanger 12, 22, 33 Outdoor heat exchanger 13, 23, 34 Compressor 14, 24 Expansion valve 15, 25, 36, 37 Flow path Switching valve 16, 26, 38 Geothermal heat exchanger 17, 27 Bypass flow path 28 Auxiliary expansion valve 50 Geothermal heat exchanger 61, 62, 63, 64 Heat exchanger switching valve 65, 66, 67, 68 Heat exchanger switching valve 71, 72, 73, 74 Bypass switching valve 75, 76, 77 Bypass switching valve 81, 82 Heat exchanger switching valve 91, 92, 93, 94 Cooling / heating switching valve

Claims (3)

An indoor heat exchanger that exchanges heat with indoor air for a phase-changeable heat medium,
An outdoor heat exchanger that exchanges heat with the outdoor air,
A compressor that compresses the heat medium of the gas phase to increase the temperature and pressure of the heat medium.
An expander that expands the heat medium of the liquid phase to reduce the pressure, and
The first flow path connection state in which the heat medium flow path connection relationship between the outdoor heat exchanger and the compressor is changed so that the heat medium exiting the compressor faces the outdoor heat exchanger, and the outdoor side. In a heat pump system including at least one or more flow path switching valves that can switch between a second flow path connection state that allows the heat medium exiting the heat exchanger to go toward the compressor.
An underground heat exchanger that is arranged outdoors and exchanges heat between a predetermined heat exchange medium that collects underground underground heat and the heat medium.
One or more heat exchanger switching valves that can switch between circulation and non-distribution of the heat medium to the geothermal heat exchanger ,
A bypass flow path in which one end can be connected to the geothermal heat exchanger and the other end can be connected to the compressor inlet side to circulate a heat medium as needed.
One or a plurality of bypass switching valves that can switch between a state in which the other end of the bypass flow path is not communicated with the compressor inlet and a state in which the other end of the bypass flow path can be communicated with the compressor inlet. Prepare,
In a state where the underground heat exchanger circulates a heat medium, when the flow path switching valve is connected to the first flow path, heat that condenses the heat medium or lowers the temperature of the heat medium. When the exchange is performed and the second flow path is connected, heat exchange is performed to evaporate the heat medium or raise the temperature of the heat medium .
A state in which the heat exchanger switching valve intervenes in the heat medium flow path between the outdoor heat exchanger and the expander so that the geothermal heat exchanger can flow through the heat medium, and a state in which the heat exchanger does not intervene. Is supposed to be switchable,
The heat exchanger switching valve allows the flow of heat medium between the underground heat exchanger and the outdoor heat exchanger, while the underground heat exchanger and the outdoor heat exchanger and the chamber. It is possible to further switch to a flow path connection state that does not allow the flow of heat medium to and from the inner heat exchanger, and one end of the bypass flow path is communicated with the underground heat exchanger to communicate the outdoor side. It is possible to separately switch between a state in which the heat medium can flow from the heat exchanger to the bypass flow path via the underground heat exchanger and a state in which one end of the bypass flow path is not communicated with the underground heat heat exchanger. A heat pump system characterized by becoming. In the heat pump system according to claim 1,
The heat pump is characterized in that the bypass switching valve is further switchable so that the other end of the bypass flow path can communicate with only one heat medium inflow port of the outdoor heat exchanger. system. In the heat pump system according to claim 1,
While the other end of the bypass flow path communicates with the heat medium flow path between the flow path switching valve and the outdoor heat exchanger on the flow path switching valve side of the bypass switching valve. It is possible to switch to a state where it is connected so that it does not communicate with the outdoor heat exchanger side.
The heat exchanger switching valve allows the flow of heat medium between the underground heat exchanger and the indoor heat exchanger, while the underground heat exchanger and the indoor heat exchanger and the chamber. The flow of heat medium to and from the outer heat exchanger is not allowed, and one end of the bypass flow path is communicated with the underground heat exchanger, and the indoor heat exchanger is passed through the underground heat exchanger. A heat pump system characterized in that it can be further switched to a flow path connection state in which a heat medium can flow between the bypass flow path and the bypass flow path.

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