JP2021173457A - Air conditioning system - Google Patents

Abstract

To provide a technology capable of improving energy efficiency at low cost, in an air conditioning system in which outside air cooled and dehumidified by an external air conditioner is reheated by a reheater installed in a plurality of air-conditioned spaces and the outside air is then blown out to the air-conditioned spaces.SOLUTION: An air conditioning system 100 comprises: an external air conditioner 20 that supplies cooled and dehumidified outside air OA to each of a plurality of air-conditioned spaces R; and a plurality of reheaters 30 installed for each of the plurality of air-conditioned spaces R to reheat the outside air OA supplied from the external air conditioner 20 to a target temperature and introduce the outside air into the air-conditioned space R. The air conditioning system comprises a common heat pump circuit 50 that supplies refrigerant as a heat source to the plurality of reheaters 30.SELECTED DRAWING: Figure 1

Description

The present invention targets an external air conditioner that supplies cooling and dehumidified outside air to each of a plurality of air-conditioned spaces, and an outside air that is installed for each of the plurality of air-conditioned spaces and is supplied from the external air conditioner. The present invention relates to an air conditioning system including a plurality of reheaters that are reheated to a temperature and introduced into the air conditioning target space.

In buildings such as hospitals, for the purpose of preventing infections, a large amount of outside air is supplied, such as all outside air conditioning that covers all air conditioning air with outside air, indoor spaces with high ventilation frequency, and indoor spaces where safety cabinets are installed. There is an indoor space that requires. Generally, the outside air cooled and dehumidified by an external air conditioner is supplied to the air-conditioned space that requires the introduction of outside air, but as described above, the outside air is supplied to the indoor space that requires the introduction of a large amount of outside air. When a relatively low temperature outside air that has been cooled and dehumidified by an air conditioner is supplied, the room temperature may become too low because the air volume is too large for the heat load corresponding to the size of the indoor space and the like. Therefore, especially for the air-conditioned space that requires the introduction of a large amount of outside air, the reheater that reheats the outside air supplied from the outside controller to the target temperature and then blows the reheated outside air into the room as blown air. (See, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2019-143826

However, in the air conditioning system described in Patent Document 1, since the reheater installed in the air conditioning target space uses hot water as a heat source, when the reheater is installed in each of a plurality of air conditioning target spaces. In order to circulate and supply hot water to each air-conditioned space, an excessively expensive hot water circulation circuit is required.
Furthermore, in small and medium-sized hospitals, individually distributed packaged air conditioners that do not use a central heat source are often used for air conditioning in each room, there is little indoor space that requires a reheater, and a hot water circulation circuit that is relatively expensive is provided. For reasons such as being unable to do so, an electrically heated reheater with high power consumption may be used as the reheater installed in each air-conditioned space, which causes deterioration of the energy efficiency of the entire air-conditioning system. There is.
In view of this situation, the main subject of the present invention is an air conditioning system in which the outside air cooled and dehumidified by an external air conditioner is reheated by a reheater installed in the air conditioning target space and then blown out to a plurality of air conditioning target spaces. The point is to provide a technology capable of improving energy efficiency at low cost.

The first characteristic configuration of the present invention is
An external air conditioner that supplies cooling and dehumidified outside air to each of multiple air-conditioned spaces,
It is an air conditioning system provided with a plurality of reheaters installed in each of the plurality of air conditioning target spaces, reheating the outside air supplied from the external air conditioner to a target temperature, and introducing the outside air into the air conditioning target space. hand,
The point is that a common heat pump circuit for supplying a refrigerant as a heat source to the plurality of reheaters is provided.

According to this configuration, the reheaters installed for each of the multiple air-conditioned spaces are supplied from a common heat pump circuit that enables highly efficient heat transfer without the need for an excessively expensive hot water circulation path. Since the refrigerant is configured to be used as a heat source, energy efficiency can be improved at low cost.

The second characteristic configuration of the present invention is
An air-conditioning indoor unit installed in the air-conditioned space and using a refrigerant supplied as at least one of a cold heat source and a hot source to perform at least one of cooling and heating in the air-conditioned space is provided.
The common heat pump circuit is configured to supply a refrigerant as at least one of a cold heat source and a hot heat source to the indoor unit for air conditioning.

According to this configuration, even when the indoor unit for air conditioning is installed in the space to be air-conditioned, the indoor unit for air conditioning receives the supply of the refrigerant from the heat pump circuit common to the plurality of reheaters and cools the refrigerant. Energy efficiency can be further improved by using as at least one of a source and a heat source to perform at least one of cooling and heating for the air-conditioned space. Further, when cooling is performed in the indoor unit for air conditioning, the energy efficiency can be further improved by using the heat recovered by the cooling for reheating the reheater through a common heat pump circuit.

The third characteristic configuration of the present invention is
The common heat pump circuit is configured to supply a refrigerant as a cold heat source to the external conditioner.

According to this configuration, the energy efficiency is further improved by receiving the supply of the refrigerant from the heat pump circuit common to a plurality of reheaters in the external air conditioner and using the refrigerant as a cold heat source to cool and dehumidify the outside air. Can be planned. Further, the energy efficiency can be further improved by using the heat recovered by cooling and dehumidifying the outside air in the external air conditioner for reheating the reheater through a common heat pump circuit.

Schematic configuration diagram of the air conditioning system of this embodiment The figure which shows the detail of the heat pump circuit of the air-conditioning system shown in FIG. Schematic configuration of an air conditioning system of another embodiment

An embodiment of the air conditioning system according to the present invention will be described with reference to the drawings.
Hereinafter, the basic configuration of the air conditioning system of the present embodiment (hereinafter referred to as the “main air conditioning system”) and the detailed configuration of the heat pump circuit provided in the present air conditioning system will be described in order.

[Basic configuration of this air conditioning system]
The basic configuration of the air conditioning system 100 will be described with reference to FIG.
The air-conditioning system 100 is installed in a building 1 such as a hospital where an air-conditioned space R including a room having a high ventilation frequency and a safety cabinet is present for the purpose of preventing infection. In the present embodiment, the building 1 has four floors, and the indoor space on each floor is the air-conditioning target space R. However, the scale of the building 1 and the division state and layout in the air-conditioning target space R can be changed as appropriate. be.

Although the detailed configuration of the air conditioner system 100 will be described later, the external air conditioner 20 that supplies the outside air OA that has been cooled and dehumidified by the cooling operation to each of the plurality of air conditioner target spaces R, and the plurality of air conditioner target spaces R. A plurality of reheaters 30 installed for each and reheating the outside air OA supplied from the external air conditioner 20 to the target temperature and introduced into the air conditioning target space R, and a plurality of reheaters 30 installed for each of the plurality of air conditioning target spaces R. An air-conditioning indoor unit 40 that performs at least one of cooling and heating is provided in the air-conditioned space R. The installation location and number of the external air conditioner 20, the reheater 30, and the air conditioning indoor unit 40 on each floor can be changed as appropriate.

The external air conditioner 20A installed on the 2nd and 4th floors of the building 1 performs cooling operation to cool and dehumidify the outside air OA to each of the reheaters 30 installed for each of the plurality of air-conditioned spaces R. It is configured to supply. Each of the reheaters 30 is configured to reheat the outside air OA supplied from the external air conditioner 20 to a target temperature and introduce it into the air conditioning target space R.

That is, the outside air OA cooled and dehumidified by the external air conditioner 20 that performs the cooling operation is supplied to the air-conditioned space R that requires the introduction of the outside air OA. Further, since the temperature of the outside air OA cooled and dehumidified by the external air conditioner 20 may be lower than the comfortable room temperature in the air conditioning target space R, the outside air conditioning is applied to the air conditioning target space R in which the outside air OA needs to be introduced. The outside air OA supplied from the machine 20 is reheated to the target temperature by the reheater 30 and then blown out as blown air.
The air conditioning system 100 is provided with a common heat pump circuit 50 that supplies a refrigerant as a heat source to the plurality of reheaters 30 in order to improve energy efficiency at low cost.

Refrigerant is also supplied from the heat pump circuit 50 as a cold heat source to the external air conditioner 20 that cools and dehumidifies the outside air OA.
The indoor unit 40 for air conditioning installed in the air-conditioning target space R on each floor is supplied with a refrigerant as at least one of a cold heat source and a hot heat source from the heat pump circuit 50, and uses the refrigerant to the air-conditioning target space R. It is configured to perform at least one of cooling and heating.
In the present embodiment, heat pump circuits 50 are separately provided for each floor of the building 1. A plurality of outdoor units 10 provided for each of the heat pump circuits 50 on each floor are installed on the roof of the building 1.

[Heat pump circuit]
The detailed configuration of the heat pump circuit 50 will be described with reference to FIG.
The heat pump circuit 50 circulates the refrigerant between the outdoor unit 10, the external air conditioner 20, the evaporator 30, and the indoor unit 40 for air conditioning, condenses the compressed high-pressure refrigerant gas, extracts heat, and expands. It is configured as a compression type refrigeration circuit that evaporates the low-pressure refrigerant liquid to take out cold heat.
Hereinafter, the detailed configurations of the outdoor unit 10, the external air conditioner 20, the reheater 30, and the air conditioning indoor unit 40 in the heat pump circuit 50 will be described in order.

(Outdoor unit 10)
The outdoor unit 10 includes a compressor 13 that compresses the low-pressure refrigerant gas LG to generate a high-pressure refrigerant gas HG, a condenser 11 that condenses the high-pressure refrigerant gas HG to generate a high-pressure refrigerant liquid HL, and the high-pressure refrigerant. An expansion valve 14 for expanding the liquid HL and an evaporator 12 for evaporating the expanded low-pressure refrigerant liquid are provided. Although not shown, the heat generated by the condenser 11 and the cold heat generated by the evaporator 12 are consumed by heat exchange between the condenser 11 and the evaporator 12, and the surplus is introduced by the fan. Released to OA.

The outdoor unit 10 has a high-pressure refrigerant gas pipe 51 through which the high-pressure refrigerant gas HG passes, a low-pressure refrigerant gas pipe 52 through which the low-pressure refrigerant gas LG passes, and a high-pressure refrigerant liquid pipe through which the high-pressure refrigerant liquid HL passes. It is connected to the road 53. The pipelines 51, 52, and 53 are provided in the building 1 in a form extending to the reheater 30, the indoor unit 40 for air conditioning, and the external air conditioner 20 installed on the air conditioning target space R side.

(External controller 20)
The external conditioner 20 includes an expansion valve 24 connected to the high-pressure refrigerant liquid pipeline 53, an opening / closing control valve 22 connected to the low-pressure refrigerant gas pipeline 52, and an opening / closing control connected to the high-pressure refrigerant gas pipeline 51. A valve 23 and a heat exchanger 21 that exchanges heat between the outside air OA taken in from the outside and the refrigerant flowing inside are provided. Further, an expansion valve 24 is connected to the refrigerant inflow / outflow portion on one side of the heat exchanger 21, and the on-off control valve 22 and the on-off control valve 23 are in parallel with the refrigerant inflow / outflow portion on the other side of the heat exchanger 21. It is connected with.

The external air conditioner 20 uses the heat exchanger 21 as a condenser and a cooling operation in which the heat exchanger 21 functions as an evaporator 21A to cool and dehumidify the outside air OA by controlling the opening and closing of the opening / closing control valves 22 and 23. The operation state can be freely switched between the heating operation and the heating operation in which the outside air OA is heated by functioning.

That is, in the external air conditioner 20A that performs the cooling operation, the on-off control valve 22 is opened and the on-off control valve 23 is closed. Then, the high-pressure refrigerant liquid HL supplied from the high-pressure refrigerant liquid pipeline 53 is expanded by the expansion valve 24, and the expanded low-pressure refrigerant liquid is supplied to the heat exchanger 21, so that the heat exchanger 21 evaporates. The low-pressure refrigerant liquid evaporates by heat exchange with the outside air OA in the evaporator 21A, and the low-pressure refrigerant gas LG generated by the evaporation flows into the low-pressure refrigerant gas pipeline 52 through the open / close control valve 22. .. As a result, in the heat exchanger 21 that functions as the evaporator 21A, the outside air OA is cooled and dehumidified by heat exchange with the refrigerant, and the outside air OA after the cooling and dehumidification is supplied to the air conditioning target space R side.
With the above configuration, each of the external conditioners 20A provided on the second floor and the fourth floor of the building 1 uses the refrigerant supplied from the heat pump circuit 50 provided on each floor as a cold heat source. Configured to be used.

On the other hand, although not shown, in the external air conditioner 20 that performs the heating operation, the on-off control valve 22 is closed and the on-off control valve 23 is opened. Then, the high-pressure refrigerant gas HG supplied from the high-pressure refrigerant gas pipeline 51 is supplied to the heat exchanger 21, and the heat exchanger 21 functions as a condenser to exchange heat with the outside air OA by the condenser. The high-pressure refrigerant gas HG is condensed, and the high-pressure refrigerant liquid HL generated by the condensation flows into the high-pressure refrigerant liquid pipeline 53 through the open expansion valve 24. As a result, in the heat exchanger 21 that functions as a condenser, the outside air OA is heated by heat exchange with the refrigerant, and the heated outside air OA is supplied to the air conditioning target space R side.
With the above configuration, each of the external conditioners 20 provided on the second floor and the fourth floor of the building 1 uses the refrigerant supplied from the heat pump circuit 50 provided on each floor as a heat source. Is also configured to be used.

(Reheater 30)
The reheater 30 is provided with a heat exchanger 31 that exchanges heat between the outside air OA after cooling and dehumidification supplied from the external air conditioner 20A that performs cooling operation and the refrigerant that flows inside. A high-pressure refrigerant gas pipeline 51 is connected to the refrigerant inflow / outflow portion on one side of the heat exchanger 31, and a high-pressure refrigerant liquid pipeline 53 is connected to the refrigerant inflow / outflow portion on the other side of the heat exchanger 31. There is.
Then, the reheater 30 causes the heat exchanger 31 to function as a condenser, and the outside air OA after cooling and dehumidification supplied from the external conditioner 20A is reheated to the target temperature by the heat exchanger 31 that functions as the condenser. Above, the reheated outside air OA is configured to be blown out to the air-conditioned space R as blown air.
That is, in the reheater 30 when the external controller 20A performs the cooling operation, the high-pressure refrigerant gas HG supplied from the high-pressure refrigerant gas pipeline 51 is supplied to the heat exchanger 31, so that the heat exchanger 31 is condensed. The high-pressure refrigerant gas HG is condensed by heat exchange with the outside air OA after cooling and dehumidifying supplied from the external conditioner 20A by the condenser, and the high-pressure refrigerant liquid HL generated by the condensation is the high-pressure refrigerant liquid. It flows into the conduit 53. As a result, in the heat exchanger 31 that functions as a condenser, the outside air OA is heated by heat exchange with the refrigerant, and the heated outside air OA is blown out to the air conditioning target space R.
With the above configuration, the plurality of reheaters 30 provided on each floor of the building 1 are configured to use the refrigerant supplied from the common heat pump circuit 50 as a heat source.

(Indoor unit 40 for air conditioning)
The indoor unit 40 for air conditioning includes an expansion valve 44 connected to the high-pressure refrigerant liquid pipeline 53, an opening / closing control valve 42 connected to the low-pressure refrigerant gas pipeline 52, and an opening / closing connection connected to the high-pressure refrigerant gas pipeline 51. A control valve 43 and a heat exchanger 41 that exchanges heat between the indoor air RA taken in from the air-conditioned space R and the refrigerant flowing inside are provided. Further, an expansion valve 44 is connected to the refrigerant inflow / outflow portion on one side of the heat exchanger 41, and the on-off control valve 42 and the on-off control valve 43 are in parallel state in the refrigerant inflow / outflow portion on the other side of the heat exchanger 41. It is connected with.

Then, in the air conditioner indoor unit 40, the heat exchanger 41 functions as the evaporator 41A by the open / close control of the open / close control valves 42 and 43 to cool the indoor air RA taken in from the air conditioner target space R, and after the cooling. Cooling operation that blows the cold air CA to the air-conditioning target space R, and the heat exchanger 41 functions as a condenser to heat the indoor air RA taken in from the air-conditioning target space R, and the heated hot air HA is used as the air-conditioning target space. The operating state can be freely switched between the heating operation that blows out to R.

That is, in the air-conditioning indoor unit 40A that performs the cooling operation, the on-off control valve 42 is opened and the on-off control valve 43 is closed. Then, the high-pressure refrigerant liquid HL supplied from the high-pressure refrigerant liquid pipeline 53 is expanded by the expansion valve 44, and the expanded low-pressure refrigerant liquid is supplied to the heat exchanger 41, so that the heat exchanger 41 evaporates. The low-pressure refrigerant liquid evaporates by heat exchange with the indoor air RA in the evaporator 41A, which functions as a vessel 41A, and the low-pressure refrigerant gas LG generated by the evaporation flows into the low-pressure refrigerant gas pipeline 52 through the open / close control valve 42. do. As a result, in the heat exchanger 41 that functions as the evaporator 41A, the indoor air RA is cooled by heat exchange with the refrigerant, and the cooled indoor air RA is blown out to the air conditioning target space R as cold air CA.
With the above configuration, the plurality of indoor units for air conditioning 40A provided on each floor of the building 1 are configured to use the refrigerant supplied from the heat pump circuit 50 provided on each floor as a cold heat source. Will be done.

On the other hand, in the air-conditioning indoor unit 40B that performs the heating operation, the on-off control valve 42 is closed and the on-off control valve 43 is opened. Then, the high-pressure refrigerant gas HG supplied from the high-pressure refrigerant gas pipeline 51 is supplied to the heat exchanger 41, so that the heat exchanger 41 functions as a condenser 41B and the condenser 41B with the indoor air RA. The high-pressure refrigerant gas HG is condensed by the heat exchange of the above, and the high-pressure refrigerant liquid HL generated by the condensation flows into the high-pressure refrigerant liquid pipeline 53 through the open expansion valve 44. As a result, in the heat exchanger 41 that functions as the condenser 41B, the indoor air RA is heated by heat exchange with the refrigerant, and the heated indoor air RA is blown out to the air conditioning target space R as warm air HA.
With the above configuration, the plurality of indoor units for air conditioning 40B provided on each floor of the building 1 are configured to use the refrigerant supplied from the heat pump circuit 50 provided on each floor as a heat source. Will be done.

[Another Embodiment]
Other embodiments of the present invention will be described. It should be noted that the configurations of the respective embodiments described below are not limited to being applied independently, but can also be applied in combination with the configurations of other embodiments.

(1) In the above embodiment, the external controller 20 utilizes a common heat pump circuit 50 that supplies a refrigerant as a heat source to the reheater 30, and the refrigerant supplied from the heat pump circuit 50 is used as a cold heat source or a heat source. However, as shown in FIG. 3, the external air conditioner 20 is configured to supply a cold heat source or a hot heat source by using a heat source circuit 27 different from the reheater 30. It doesn't matter.
For example, in such a heat source circuit 27, similarly to the heat pump circuit 50 described above, while circulating the refrigerant between the outdoor unit 25 and the external air conditioner 20, the compressed high-pressure refrigerant gas is condensed to generate heat. It can be a compression type refrigerating circuit that takes out cold heat by evaporating the expanded low-pressure refrigerant liquid as well as taking it out. Alternatively, the circuit may be such that the cold water or hot water generated by the outdoor unit 25 is circulated with the external controller 20.

(2) In the above embodiment, the external air conditioner 20 is configured to be able to switch the operating state between the cooling operation for cooling and dehumidifying the outside air OA and the heating operation for heating the outside air OA. It may be used as an external air conditioner that performs only cooling operation without performing the operation.

(3) In the above embodiment, the indoor unit 40 for air conditioning is configured to be able to switch the operating state between a cooling operation for cooling the indoor air RA and a heating operation for heating the indoor air RA. An indoor unit and a heating indoor unit dedicated to heating operation may be provided separately. Further, these indoor units for air conditioning may be omitted as appropriate.

20, 20A External conditioner 30 Reheater 40, 40A, 40B Air conditioning indoor unit 50 Heat pump circuit OA Outside air R Air conditioning target space

Claims (3)

An external air conditioner that supplies cooling and dehumidified outside air to each of multiple air-conditioned spaces,
It is an air conditioning system provided with a plurality of reheaters installed in each of the plurality of air conditioning target spaces, reheating the outside air supplied from the external air conditioner to a target temperature, and introducing the outside air into the air conditioning target space. hand,
An air conditioning system provided with a common heat pump circuit that supplies a refrigerant as a heat source to the plurality of reheaters. An air-conditioning indoor unit installed in the air-conditioned space and using a refrigerant supplied as at least one of a cold heat source and a hot source to perform at least one of cooling and heating in the air-conditioned space is provided.
The air conditioning system according to claim 1, wherein the common heat pump circuit supplies the refrigerant to the air conditioning indoor unit as at least one of a cold heat source and a hot heat source. The air conditioning system according to claim 1 or 2, wherein the common heat pump circuit is configured to supply a refrigerant as a cold heat source to the external air conditioner.

Images