JPH074768A - Heat storage type air conditioning system - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a heat storage type air conditioning system in which a heat medium storing cold heat is circulated in an indoor unit and indoor air is cooled by the heat medium to improve heat storage utilization efficiency. [Structure] An outdoor unit A including a compressor 1 and an outdoor heat exchanger 3
And a heat storage device B having a heat storage flow control valve 9, a heat storage heat exchanger 8, a heat medium 11 stored in a tank 10, an indoor flow control valve 7, and indoor units C and D having an indoor heat exchanger 6. Consists of
The heat medium 11 is formed by forming a refrigeration cycle between the outdoor unit and the heat accumulator.
To store cold heat, and to form a refrigeration cycle between the outdoor unit, the heat storage unit, and the indoor unit to supercool the refrigerant by the cold heat of the heat medium 11 and evaporate it in the first indoor heat exchanger 6 to cool the indoor air. In the air conditioning system, a pump 15 connected to the tank 10, an indoor heat exchanger 16 and an indoor flow rate control valve 17 provided in each indoor unit are provided, and the heat medium 11 stores cold heat therein.
A circulation circuit of the heat medium 1 is formed by another indoor heat exchanger 16
1, the indoor air is cooled.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat storage type air conditioning system suitable for utilizing heat storage.

[0002]

2. Description of the Related Art A conventional technique will be described with reference to FIG. The heat storage type air conditioning system is roughly divided into an outdoor unit A ′, a heat storage unit B ′, an indoor unit C ′ and an indoor unit D ′, and these devices are connected by a liquid pipe and a gas pipe.

During heat storage operation for storing cold heat in the heat storage device B ',
The compressor 1 and the outdoor heat exchanger 3 of the outdoor unit A ′, the heat storage flow control valve 9 and the heat storage heat exchanger 8 of the heat storage device B ′ are sequentially connected to form a refrigeration cycle, and the refrigerant is used as heat storage heat. Heat medium (water) 1 in the heat storage tank 10 when evaporating in the exchanger 8
1, so that cold heat is stored in the heat medium (water) 11.

During the cooling operation using heat storage utilizing the cold heat stored in the heat storage device B ', the compressor 1 and the outdoor heat exchanger 3 of the outdoor unit A', the heat storage heat exchanger 8 of the heat storage device B ', The indoor flow rate control valve 7 of the indoor units C'and D'and the indoor heat exchanger 6 are sequentially connected to form a refrigeration cycle. In this refrigeration cycle, the refrigerant condensed in the outdoor heat exchanger 3 is supercooled in the heat storage heat exchanger 8 by the heat medium 11 that stores cold heat, expanded by the indoor flow control valve 7, and expanded in the indoor heat exchanger. 6 evaporates, and at this time, the indoor air is cooled in the indoor heat exchanger 6 and provided for indoor cooling.

The air conditioner has a low pressure detecting means 22 for detecting a refrigerant evaporation pressure in the heat storage heat exchanger 8 and a water level detecting for detecting a water level change in the heat storage tank 10 caused by solidification of the heat medium (water) 11. Means 23 are provided, and a control device 24 that controls the amount of refrigerant circulation in the refrigeration cycle by control signals from the detection means 22 and 23, and an inverter control device 25 that drives the compressor 1 by an inverter. It is equipped with. Such an air conditioner has a so-called multi-type configuration in which a plurality of indoor units are connected in parallel to one outdoor unit.

[0006] As a conventional example of the heat storage utilization system by the supercooling of the refrigerant, there is a technique described in Japanese Patent Application No. 2-306064, "Operation control device for heat storage type air conditioning conditioner".

[0007]

In the cooling operation utilizing heat storage in the conventional example, since the refrigerant in the refrigeration cycle is supercooled by the heat storage energy in the heat storage tank, the refrigerant is cooled to 0 ° C. or less. However, there is a problem in that the effect of utilizing heat storage is generally reduced under low load compared to under high load.

An object of the present invention is to provide a heat storage type air conditioner in which the heat storage utilization efficiency is improved by circulating the heat medium itself of the heat storage unit to the indoor unit.

[0009]

In order to achieve the above object, a heat storage type air conditioning system of the present invention comprises an outdoor unit having a compressor and an outdoor heat exchanger, an expansion valve, a heat storage heat exchanger and It consists of a heat storage device with the heat medium stored in the tank, and an indoor unit with another expansion valve and indoor heat exchanger.Compressor, indoor heat exchanger, heat storage heat exchanger, another expansion A valve and an indoor heat exchanger are sequentially connected to form a refrigeration cycle, and the refrigerant is supercooled by the cold heat stored in the heat medium in the heat storage heat exchanger and evaporated in the indoor heat exchanger to cool the indoor air. In addition to the system described above, a pump connected to the tank, another indoor heat exchanger and another indoor flow rate control valve are provided in the indoor unit, and a circuit for circulating a heat medium storing cold heat by connecting these with piping It is characterized by being formed.

The flow rate of the heat medium flowing through the circulation circuit is controlled on the basis of the load of the indoor unit.
It is preferable to provide a means for controlling another indoor flow rate control valve so that the ratio of the flow rate of the heat medium to the load becomes large.
Further, on the inlet side of the pump for circulating the heat medium, a connection switching unit and a heating dedicated heat storage device having a heat medium for storing warm heat in one of the connection switching units are provided, and cold heat is stored in the other of the connection switching units. You may connect the tank which has a heating medium.

[0011]

In the heat storage type air conditioning system of the present invention, a refrigeration cycle is formed from the compressor, the indoor heat exchanger, the heat storage heat exchanger, another expansion valve and the indoor heat exchanger, and the heat storage heat exchanger is used. , Supercooling the refrigerant by the cold heat already stored in the heat medium, performing one heat storage utilizing cooling operation of cooling the indoor air by evaporating in the indoor heat exchanger, a tank having a heat medium storing the cold heat, a pump, Another indoor heat exchanger and another indoor flow control valve form a circuit for circulating a heat medium storing cold heat, and another indoor heat exchanger cools indoor air by the heat medium. Since the operation is performed, a large amount of heat storage energy can be used by circulation of the heat medium itself, rather than a single heat storage-use cooling operation by supercooling the refrigerant, and the compressor drive power can be reduced and power consumption can be reduced. .

Further, during heating, the connection switching unit switches from the tank having the heat medium storing the cold heat to the heat storage dedicated to heating, and the heat storage dedicated to heating, the pump, another indoor heat exchanger, and another indoor By forming a circuit that circulates the heat medium that stores warm heat from the flow control valve, you can warm the indoor air with the heat medium of warm heat in another indoor heat exchanger. It is possible to reduce the power consumption by eliminating the lack of capacity, performing a heating operation by forming a refrigeration cycle from an outdoor unit and an indoor unit, and using a dedicated heat storage device for heating together.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an overall configuration diagram of a heat storage type air conditioning system (hereinafter simply referred to as an air conditioning system) according to one embodiment of the present invention, and FIG. 2 shows heat load fluctuation and heat storage utilization state of the air conditioning system in a low load day. FIG. 3, FIG. 3 is a control block diagram of the air conditioning system of one embodiment, and FIG. 4 is a diagram showing heat load fluctuations and heat storage utilization states of the air conditioning system during a high load day.

As shown in FIG. 1, the air conditioning system of this embodiment is roughly divided into an outdoor unit A, a heat accumulator B, a plurality of indoor units C and D, and a heat medium circulation unit 20. The outdoor unit A, the heat storage unit B, and the indoor units C and D are refrigerant liquid piping 1
4a and the refrigerant gas pipe 14b to form a refrigeration cycle, and the heat accumulator B, the plurality of indoor units C and D, and the heat medium circulation unit 20 are connected by the heat medium pipe 18.
A circuit for circulating the heat medium in the heat storage device B is formed. Further, the indoor units C and D are connected to the heating-dedicated unit 21 via the heat medium circulation unit 20 by piping to be connected to the heating-dedicated unit 2
A circuit for circulating the heat medium in 1 is formed.

The outdoor unit A includes a compressor 1, a four-way valve 2, an outdoor heat exchanger 3, an outdoor flow control valve 4, and an accumulator installed between the four-way valve 2 and the compressor 1, which are sequentially connected. 5, a low pressure detecting means 22 for detecting the refrigerant evaporation pressure between the four-way valve 2 and the accumulator 5, and the outdoor flow rate control valve 4 is provided via the refrigerant liquid pipe 14a, and the four-way valve 2 is provided. Both are connected to the heat storage device B via the refrigerant gas pipe 14b, and the compressor 1 has a capacity control function.

The heat storage device B includes a heat storage flow control valve 9, a heat storage heat exchanger 8, a switching valve 13, which are sequentially connected to the refrigerant gas pipe 14b from the outdoor unit A, and a heat storage heat exchanger 8 as a heat medium ( The heat storage tank 10 stored in water), the switching valve 12 branching from between the heat storage heat exchanger 8 and the switching valve 13 and connected to the refrigerant gas pipe 14b, and the heat medium (water) 11 in the heat storage tank 10 are solidified. And a water level detecting means 23 for detecting a water level change caused by the indoor unit C, the switching valve 13 through the refrigerant liquid pipe 14a.
Connected to D. Further, the heat storage tank 10 is connected to the indoor units C and D via a heat medium circulation unit 20 by a heat medium pipe 18, and these form a circulation circuit for circulating the heat medium 11 in the heat storage tank 10.

The heat medium circulation unit 20 is provided inside or outside the heat accumulator B, and is composed of a circulation system selection valve 19 and a circulation pump 15 as a connection switching unit.
The circulation system selection valve 19 switches between the heat medium 11 that stores the cold heat from the heat storage tank 10 or the heat medium that stores the warm heat from the separately provided heating unit 21, and the circulation pump 15 is the circulation system selection valve. The heat medium selected in 19 is sent to the indoor units C and D.

The indoor units C and D have the same refrigeration cycle configuration, and each indoor unit has a first indoor flow control valve 7 and a first indoor flow rate control valve 7 which are sequentially connected to the switching valve 13 of the heat storage device B via a refrigerant liquid pipe 14a. 1 indoor heat exchanger, and a circulation pump 1
5 is provided with a second indoor flow valve and a second heat exchanger, which are sequentially connected to each other via the heat medium pipe 18. The first indoor heat exchanger is connected to the outdoor unit A via the refrigerant gas pipe 14a, and the second heat exchanger 16 and the second indoor flow valve 17 are the heat storage tank 1
0, the circulation system selection valve 19 and the circulation pump 15 are sequentially connected by the heat medium pipe 18 to form a circulation circuit. One or more indoor units shall be installed.

Further, this air conditioning system is a control device for controlling the refrigerant circulation amount in the refrigeration cycle by the detection signals of the low pressure detecting means 22 provided in the outdoor unit A and the water level detecting means 23 provided in the heat accumulator B. 24, and an inverter control device 25 for driving the compressor 1 by the inverter.

According to the air conditioning system configured as described above, the heat storage operation of forming a refrigeration cycle between the outdoor unit A and the heat storage unit B to store cold heat in the heat storage unit B, and the outdoor unit A A heat storage-use cooling operation in which a refrigeration cycle is configured between the heat storage unit B and a plurality of indoor units C and D to perform air conditioning using heat storage;
Operation modes such as a normal cooling operation or a heating operation that does not substantially utilize heat storage by forming a refrigeration cycle between the outdoor unit A and the indoor units C and D, and other heat storage-use heating operation that uses the dedicated heating unit 21 Can be taken.

The heat storage operation is performed by forming a refrigeration cycle between the outdoor unit A and the heat storage unit B. That is, the refrigerant is the compressor 1
Is discharged at a high temperature and high pressure from the
It is condensed in the outdoor heat exchanger 3, decompressed and expanded by the heat storage flow control valve 9 that functions as an expansion valve, evaporated by the heat storage heat exchanger 8 that functions as an evaporator, and then switched from the refrigerant gas pipe 14b to the switching valve 12, four-way direction. It returns to the compressor 1 via the valve 2 and the accumulator 5, and at this time, the heat medium 11 in the heat storage tank 10 is cooled by exchanging heat with the refrigerant evaporated in the heat storage heat exchanger 8 to cool the heat. store. In this refrigeration cycle, the outdoor flow control valve 4 of the outdoor unit A is fully opened and the switching valve 13 of the heat storage device B is fully closed. Note that this heat storage operation is performed using night electricity, which is cheap.

In one cooling operation using heat storage, a refrigeration cycle is constructed between the outdoor unit A, the heat storage unit B, and the indoor units C and D. That is, the refrigerant is discharged from the compressor 1 at high temperature and high pressure, fed through the four-way switching valve 2, condensed in the outdoor heat exchanger 3, and cooled in the heat storage heat exchanger 8 by the heat storage operation. 11 is supercooled by exchanging heat with 11, is adiabatically expanded by the indoor flow control valve 7 that operates as a pressure reducing device, and is evaporated by the first indoor heat exchanger 6 to cool the indoor air, and the refrigerant gas pipe 14b
Then, it returns to the compressor 1 through the switching valve 12, the four-way valve 2 and the accumulator 5. Therefore, the refrigerant is the heat storage heat exchanger 8
Since the cooling capacity of the supercooled part is increased, it becomes possible to reduce the amount of refrigerant circulation in the refrigeration cycle, the compressor drive power is decreased, and compared with the cooling operation of the air conditioner without a heat storage device. The power consumption of the compressor can be reduced.

In another cooling operation utilizing heat storage, the heat medium 11 cooled by the heat storage operation is transferred to the heat storage device B and the indoor units C and D.
It circulates between. In this cooling operation using heat storage, the heat medium 11 that has stored cold heat in the heat storage tank 10 passes through the heat medium piping 18 by the circulation pump 15 through the circulation system selection valve 19 that constitutes the heat medium circulation unit 20 The second indoor heat exchanger 16 exchanges heat with the indoor air in each of the indoor units C and D, and the cooled air is used for indoor cooling. The flow rate of the heat medium 11 to the indoor units C and D is controlled by the second indoor flow rate control valve 17. The heat medium 11 returned from the indoor units C and D to the heat medium circulation unit 20 through the heat medium pipe 18 returns to the heat storage tank 10 in the heat accumulator B via the heat medium circulation system selection valve 19.

The air conditioning system of the present invention is characterized in that the other heat storage utilizing cooling operation is performed in parallel with the heat storage utilizing cooling operation by supercooling of the refrigerant. It is possible to improve the heat storage utilization efficiency under load as compared with the conventional heat storage utilization operation only by supercooling the refrigerant.
In FIG. 2, the horizontal axis represents the time of day and the vertical axis represents the load of the air conditioning system at each time. A curve a represents the capacity of a normal cooling operation, a curve b represents a capacity of a cooling storage-based cooling operation for supercooling a refrigerant, and a curve c represents a cooling storage-based cooling operation of supercooling a refrigerant and a storage-based cooling operation of circulating a heat medium. It shows the ability by combined parallel operation. Therefore, the difference between the curves b and a depends on the cooling capacity by the refrigerant supercooling, and the curve c.
The difference between b and b indicates the cooling capacity by the heat medium circulation.

FIG. 3 shows a first indoor flow rate control valve 7 and a second indoor flow rate control valve for controlling the flow rates of the first indoor heat exchanger 6 and the second indoor heat exchanger 16 provided in the indoor units C and D. 1
7 is a system diagram for controlling 7 according to information from an external signal detecting means 26. FIG. For example, as the external signal 26, each indoor unit C,
By detecting the heat load of D, as shown in FIG. 4, when the load is small, the flow rate of the heat medium 11 can be increased to increase the heat storage utilization efficiency, and when the heat load is large, the flow rate of the heat medium 11 can be increased. The heat storage operation capacity of refrigerant supercooling accompanying the operation of the compressor can be reduced. Curve a in FIG.
b and c show the same cooling capacity as in FIG.

The cooling / heating operation that does not use heat storage is performed by forming a refrigeration cycle with the outdoor unit A and the indoor units C and D. During the cooling operation without using heat storage, the refrigerant is discharged from the compressor 1 at high temperature and high pressure, fed through the four-way switching valve 2, condensed in the outdoor heat exchanger 3, passes through the heat storage device B, and operates as a pressure reducing device. Adiabatic expansion is performed by the indoor flow rate control valve 7, which is evaporated by the first indoor heat exchanger 6 to cool the indoor air at that time, and then the indoor air is again passed through the heat storage device B, and the four-way valve 2 of the outdoor unit A and the accumulator. Return to compressor 1 via switch 5. In this refrigeration cycle, the outdoor flow rate control valve 4 is open. on the other hand,
During the heating operation without using heat storage, the refrigerant is discharged from the compressor 1 at high temperature and high pressure, is fed through the four-way switching valve 2, passes through the heat storage unit B, and passes through the first indoor heat of each indoor unit C, D. Exchanger 6
At that time, the indoor air is heated, and then the indoor air is heated again, and then the raw air is again passed through the heat accumulator B, expanded by the outdoor flow rate control valve 4 acting as an expansion valve, and exchanged with the outdoor air by the outdoor heat exchanger 3 to evaporate, Compressor 1 via four-way valve 2 and accumulator 5
Return to. In this refrigeration cycle, the first indoor flow rate control valve 7 is open.

During the heating operation, the heat medium stored in the heat storage means of another system suitable for heating the boiler or the like is used by the heat medium circulation unit 20 via the circulation system selection valve 19 to similarly perform the second indoor heat exchange of the indoor unit. Circulator 16 and second indoor flow control valve 17, circulation system selection valve 19 circulated through heat medium circulation pipe
The heating system utilizing the heat storage is performed by returning the heating system to the heating only unit 21 via the heating unit 21. As a result, a heating system not using only the heat pump becomes possible.

Further, in the system according to the present invention, even when the outdoor unit A is maintained in the daytime, air conditioning is performed by the heat storage utilizing cooling operation in which the heat medium is circulated and the heat accumulation utilizing heating operation in which the heat medium is circulated by the separate heating system. Maintenance can be done while performing.

[0029]

According to the present invention, a heat storage type air conditioning system is provided with an outdoor unit equipped with a compressor and an outdoor heat exchanger, an expansion valve, a heat storage heat exchanger, and a heat medium stored in a tank. In addition to a system consisting of a heat storage unit, an expansion unit, and an indoor unit equipped with an indoor heat exchanger, a pump connected to the tank, another indoor heat exchanger for the indoor unit, and another indoor flow rate control valve. Since it is configured to form a circuit that circulates a heat medium that stores cold heat by connecting these with piping, a refrigeration cycle is formed from an outdoor unit, a heat storage unit, and an indoor unit, and an indoor heat exchanger is used. The indoor air is cooled by the supercooled refrigerant to perform cooling, and the indoor air can be cooled by the heat medium itself in another indoor heat exchanger in the circulation circuit of the heat medium that stores the cold heat, thus cooling the refrigerant. Rather than one cooling operation using heat storage by supercooling, Significant heat storage energy by the ring -
It is possible to reduce the driving power of the compressor and the power consumption.

In the case where the above heat storage type air conditioning system is provided with a heat storage unit for heating having a heat medium for storing warm heat,
A heat medium that stores warm heat from a tank with a heating medium for cold heat during heating by switching from a tank with a heat medium for heating to a heat storage device for heating only, from a heat storage device for heating only, a pump, another indoor heat exchanger, and another indoor flow control valve. By forming a circuit that circulates, the indoor air can be warmed by the heat medium of warm heat in another indoor heat exchanger, the lack of heating capacity at startup can be resolved, and the refrigeration cycle from the outdoor unit and the indoor unit. It is possible to reduce the power consumption by performing the heating operation by forming the above and using the heat storage dedicated to the heating together.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a heat storage type air conditioning system according to an embodiment of the present invention.

FIG. 2 is a diagram showing an example of load fluctuation and heat storage utilization of the air conditioning system in one day.

FIG. 3 is a control block diagram of a heat storage utilization operation by circulating a heat medium.

FIG. 4 is a diagram showing another example of load fluctuation and heat storage utilization of the air conditioning system in one day.

FIG. 5 is a diagram showing a conventional heat storage type air conditioning system.

[Explanation of symbols]

 1 Compressor 2 Four-way valve 3 Outdoor heat exchanger 4 Outdoor flow control valve 5 Accumulator 6 First indoor heat exchanger 7 First indoor flow control valve 8 Heat storage heat exchanger 9 Heat storage flow control valve 10 Heat storage tank 11 heat medium 12,13 switching valve 14a refrigerant liquid piping 14a refrigerant gas piping 15 circulation pump 16 second indoor heat exchanger 17 second indoor flow control valve 18 heat medium piping 19 circulation system selection valve 20 circulation unit 21 heating only unit 22 Low pressure detection means 23 Water level detection means 24 Inverter frequency calculation means 25 Inverter control device 26 External signal detection means

Claims (4)

[Claims] 1. An outdoor unit having a compressor and an outdoor heat exchanger, an expansion valve, a heat storage heat exchanger and a heat storage tank having a heat medium storage tank, and another expansion valve and an indoor heat exchanger. And a compressor, an outdoor heat exchanger, an expansion valve and a heat storage heat exchanger are sequentially connected to form a refrigeration cycle, and the heat storage heat exchanger stores cold heat in a heat medium. Then
In addition, a compressor, an indoor heat exchanger, a heat storage heat exchanger, another expansion valve and an indoor heat exchanger are sequentially connected to form a refrigeration cycle, and the cold heat stored in the heat medium by the heat storage heat exchanger is used. In a heat storage type air conditioning system that supercools a refrigerant and evaporates it in an indoor heat exchanger to cool indoor air, a pump connected to a tank, an indoor heat exchanger and another indoor flow control valve A heat storage type air conditioning system characterized in that a circuit for circulating a heat medium is formed by connecting these pumps, another indoor heat exchanger, and another indoor flow rate control valve. 2. A heat storage type air conditioning system comprising means for controlling the other indoor flow rate control valve based on the load of the indoor unit. 3. The means for controlling the other indoor flow rate control valve is provided such that the smaller the load of the indoor unit, the larger the ratio of the flow rate of the heat medium to the load. The heat storage type air conditioning system described. 4. A connection switching unit is provided on the inlet side of the pump, and a heating dedicated heat accumulator having a heat medium for storing warm heat is connected to one of the connection switching units, and the other of the connection switching units is provided with the above-mentioned heat storage device. The heat storage type air conditioning system according to claim 1, wherein a tank is connected.