JPH11201507A - Thermal storage type air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a regenerative air conditioner to improve the efficiency of effective utilization of storage cold heat and reduce an amount of working power by a method wherein a whole of a refrigerant flowing through a refriger ant circuit is caused to pass a heat exchanger for heat collection and storage cold heat recovered from a heat storage medium is regulatable. SOLUTION: This air conditioner comprises a compressor 2, a condenser 3, a first pressure reducing mechanism 4, a heat exchanger 5 for heat collection to collect heat from a heat storage medium W from collection of heat, a second pressure reducing mechanism 6, and a vaporizer 7, which are successively connected in the order to form a refrigerant circuit 1. By changing the refrigerant pressure of the heat-exchange 5 for heat collection through control of the valve opening of the first pressure reducing mechanism 4, heat collection capacity of the heat-exchanger 5 for heat collection is regulated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a regenerative air conditioner having a heat collecting heat exchanger for collecting heat from a heat storage medium in a refrigerant circuit in order to suppress and level power during the day. It is.

[0002]

2. Description of the Related Art FIG. 9 shows the overall configuration of a regenerative air conditioner disclosed in Japanese Patent Publication No. 7-94931.
2 is a compressor, 3 is a condenser of a refrigerant formed of a heat exchanger on the outdoor side, that is, a heat source side, 14 is a first electronic expansion valve as a pressure reducing mechanism for reducing the pressure of the refrigerant condensed in the condenser 3, and 7 is A refrigerant evaporator comprising a heat exchanger on the indoor side, that is, a use side, wherein each of the devices 2, 3, 14, and 7 is a refrigerant pipe 8
The refrigerant circuit 1 is sequentially connected so that the refrigerant can flow therethrough, and a refrigerant circuit 1 having a heat pump function of applying cold heat obtained by heat exchange with outdoor air in the condenser 3 to the interior in the evaporator 7 is configured.

[0003] Reference numeral 11 denotes an inverter for variably adjusting the operating capacity of the compressor 2. The inverter 11 determines the operating capacity of the compressor 2 as an output frequency F.
Therefore, the inverter 11 has a function as a means for detecting the operating capacity of the compressor 2. Further, as an accessory of the refrigerant circuit 1, a receiver 15 for temporarily storing the refrigerant is provided downstream of the condenser 3, and a liquid refrigerant in a suction gas to the compressor 2 is separated upstream of the compressor 2. The accumulator 10 for performing the operation is arranged.

In this air conditioner, a heat storage tank 9 for storing water as a heat storage medium W capable of storing heat is arranged. In the heat storage tank 9, heat is exchanged with a refrigerant during an ice making operation to store heat. A heat-exchanging heat exchanger 5 which functions as an ice-making coil for making ice in the water in the tank 9 and supercools the refrigerant with cold heat from the heat storage medium W (ice) during the cold storage heat recovery operation is provided. The liquid line 8 between the condenser 3 of the refrigerant circuit 1 and the first electronic expansion valve 14 is sequentially provided from the upstream side by the first branch pipe 16a, the heat exchanger 5 for heat collection, and the second branch pipe 16b.
a is provided bypassing a, and a branch channel 13 is configured to branch a part of the liquid refrigerant and then to join the liquid line 8a again.

In the refrigerant circuit 1, the first branch pipe 1
6a, the liquid line 8a between the two branch points of the second branch pipe 16b (that is, the branch point P and the junction point R of the branch flow path 13 and the liquid line 8a) is provided with a second electronic expansion valve whose opening can be adjusted. 1
7 (decompression mechanism) is provided, a first on-off valve 18 for switching the opening and closing of the first branch pipe 16a is provided on the first branch pipe 16a, and a second on-off valve whose opening degree can be adjusted is provided on the second branch pipe 16b. A three-electron expansion valve 19 (decompression mechanism) is provided.

The first on-off valve 18 and the heat exchanger 5 for heat collection
Between the first branch pipe 16a and the gas line 8 of the refrigerant circuit 1.
b is provided with a third branch pipe 16c that is connected to allow refrigerant to flow therethrough, and the third branch pipe 16c is provided with a second on-off valve 20 that switches the opening and closing of the third branch pipe 16c. And
When both the first on-off valve 18 and the second on-off valve 20 are closed, the refrigerant cannot be bypassed from the refrigerant circuit 1, while when the first on-off valve 18 is open and the second on-off valve 20 is closed A part of the refrigerant flowing through the liquid line 8a of the refrigerant circuit 1 is diverted to the branch channel 13 and passes through the first branch pipe 16a, the heat-exchange heat exchanger 5, and the second branch pipe 16b.
To join. At this time, by mutually adjusting the opening degrees of the second and third electronic expansion valves 17 and 19,
The flow rate of the refrigerant flowing on the side of the branch channel 13 relative to the flow rate of the refrigerant flowing on the liquid line 8a side, that is, the branching rate is adjusted. That is, the second and third electronic expansion valves 17 and 19
Constitutes a diversion control mechanism.

On the other hand, when the first opening / closing valve 18 and the first electronic expansion valve 14 are closed and the second electronic expansion valve 17 and the second opening / closing valve 20 are open, a part of the liquid refrigerant flowing through the liquid line 8a is removed. The refrigerant flows from the second branch pipe 16b to the gas line 8b via the heat exchanger for heat collection 5 and the third branch pipe 16c, and at this time, the refrigerant decompressed by the third electronic expansion valve 19 is cooled by the heat exchanger for heat collection. The heat storage medium W (water) in the heat storage tank 9 is made into ice to store cold heat by evaporating in the heat storage tank 5, and the third electronic expansion valve 19 and the heat exchanger 5 for heat collection store the cold heat. A heating means is provided. In addition, the first and second
A circulation path switching mechanism that switches the circulation path of the refrigerant by the on-off valves 18 and 20 is configured. As described later, the first and second on-off valves 18 and 20 do not open at the same time.

Further, this air conditioner is provided with many sensors. Thi is disposed upstream of the branch point P of the liquid line 8a, and is an inlet temperature sensor as inlet temperature detecting means for detecting the temperature (inlet temperature) of the liquid refrigerant before the branch, and Th is downstream of the junction R of the liquid line 8b. And an outlet temperature sensor as an outlet temperature detecting means for detecting the temperature (outlet temperature) of the liquid refrigerant after the merging, Th1 is arranged at an air inlet of the evaporator 7, detects a room temperature, and detects the room temperature. A room temperature sensor as a load detecting means for detecting an air-conditioning load from a temperature difference from a set temperature, Th2 is a suction pipe sensor arranged on a suction pipe of the compressor 2 and detecting a suction pipe temperature, Sp1
Is a low-pressure sensor that is disposed in the suction pipe and detects a saturation temperature corresponding to the evaporation pressure of the refrigerant (hereinafter referred to as “evaporation temperature”), which is the physical state of the suction refrigerant. Sp2 is disposed in the discharge pipe of the compressor 2 and This is a high-pressure sensor that detects the saturation temperature corresponding to the condensation pressure of the refrigerant, which is a physical state quantity (hereinafter, referred to as “condensation temperature”). The temperature difference (T2-Te) between the temperature T2 of the suction superheated refrigerant detected by the suction pipe sensor Th2 and the evaporation temperature Te detected by the low pressure sensor Sp1 indicates that the refrigerant in the ice making operation (during the cold storage operation). The degree of superheat Sh is determined.

Each of the sensors is connected to a controller 12 as operation control means for controlling the operation of the entire apparatus. This controller 12 operates the apparatus and controls the sensors Thi, Th0, Th1, Th2, Sp2, Sp1, and Sp.
2, the valves 14, 17, 18, 1
The opening and closing of the valves 9 and 20 and the valve opening are controlled.

Next, each operation state of the device configured as described above will be described. During normal cooling operation without heat storage recovery, the first electronic expansion valve 14 is closed with the first and second on-off valves 18 and 20 closed and the second electronic expansion valve 17 opened.
After the refrigerant compressed by the compressor 2 is condensed by the condenser 3, the refrigerant flows only through the liquid line 8 a without being diverted to the side of the branch channel 13, (1) The pressure is reduced by the electronic expansion valve 14, circulated so as to evaporate in the evaporator 7 and return to the compressor 2.

During the ice making operation, the third electronic expansion valve 19 is opened while the first electronic expansion valve 18 and the first electronic expansion valve 14 are closed and the second electronic expansion valve 17 and the second electronic expansion valve 20 are open. The operation is performed while adjusting the temperature appropriately, and the refrigerant condensed in the condenser 3 is reduced in pressure by the third electronic expansion valve 19,
The heat storage medium W in the heat storage tank 9 evaporates in the heat collection heat exchanger 5.
After the heat storage medium W (water) is made into ice by heat exchange with the water, the heat storage medium W (water) is circulated to return to the suction side (see the solid line arrow in FIG. 9). During the ice making operation, the suction superheat S obtained from the measured values of the suction pipe sensor Th2 and the low-pressure sensor Sp1.
The opening of the third electronic expansion valve 19 is controlled so that h matches the target value.

Further, after the ice making operation, the first open / close valve 18 is opened during the cold storage heat recovery operation in which the heat storage is recovered, that is, the ice in the heat storage tank 9 is melted and the cooling operation using the cold is performed. In a state where the second on-off valve 20 is closed, the operation is performed while mutually adjusting the opening degrees of the second electronic expansion valve 17 and the third electronic expansion valve 19, and a part of the refrigerant condensed in the condenser 3 is removed. The liquid is diverted from the liquid line 8a to the branch channel 13 side, and is supercooled by heat exchange with the heat storage medium W (ice) in the heat exchanger 5 for heat collection, while the remaining refrigerant is directly cooled without being supercooled. 8a. Then, after they are joined at the junction R, the pressure is reduced by the first electronic expansion valve 14, the water is evaporated by the evaporator 7 and circulated back to the compressor 2 for cooling (FIG. 9).
Dashed arrow).

During the cold storage heat recovery operation, the target outlet temperature Tos of the liquid refrigerant after the joining is set by the target temperature setting means (not shown), and the outlet temperature sensor is set by the branching control means (not shown). The shunt adjusting mechanism including the second electronic expansion valve 17 and the third electronic expansion valve 19 is controlled such that the outlet temperature To detected at Th approaches the target outlet temperature Tos. That is, the refrigerant branch rate is adjusted based on the difference between the target outlet temperature Tos and the outlet temperature To.

[0014]

However, in the conventional heat storage type air conditioner, in order to control the amount of heat taken from ice in the heat storage tank 9 by the heat collection heat exchanger 5, heat exchange for heat collection is performed. Refrigerant flows into the circuit on the liquid line 8a side that bypasses the heat exchanger 5, and this refrigerant and the heat-exchanging heat exchanger 5
When the required heat collection capacity is small, the flow of the refrigerant is reduced smoothly by the decrease in the flow rate of the refrigerant on the side of the branch channel 13 because the increase in the enthalpy difference due to ice is wasted because the refrigerant that has passed through the flow path merges with the refrigerant. There was a problem that it was not done.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to allow all of the refrigerant flowing through a refrigerant circuit to pass through a heat exchanger for heat collection, and to recover cold from a heat storage medium. An object of the present invention is to provide a regenerative air conditioner capable of controlling heat to improve an effective utilization rate of cold storage heat and reduce the amount of electric power used.

[0016]

In order to achieve the above object, a regenerative air conditioner according to the present invention comprises a compressor, a condenser,
A first pressure reducing mechanism, a heat collecting heat exchanger for collecting heat from the heat storage medium, a second pressure reducing mechanism, and a refrigerant circuit formed by sequentially connecting the evaporator; and a valve of the first pressure reducing mechanism. By controlling the opening degree and changing the refrigerant pressure in the heat collecting heat exchanger, the heat collecting capacity of the heat collecting heat exchanger is adjusted.

[0017]

Embodiments of the present invention will be described below. In the regenerative air conditioner of the present invention, during the cold storage heat recovery cooling operation, all of the liquid refrigerant flowing through the liquid line of the refrigerant circuit is circulated to the heat exchanger for heat collection, and the pressure of the condenser and the heat exchange for heat collection are changed. Adjusting the pressure of the heat-collecting heat exchanger by adjusting the pressure of the heat exchanger by the first pressure-reducing mechanism so that “pressure of the condenser ≧ pressure of the heat-collecting heat exchanger”. Specifically, as shown in FIG. 1, a compressor 2, a condenser 3, a first decompression mechanism 4, a heat-exchanging heat exchanger 5, a second decompression mechanism 6, and an evaporator 7 are sequentially connected in series. It has a refrigerant circuit 1 formed by connecting pipes, a heat storage tank 9 containing the heat exchanger 5 for heat collection, and a heat storage medium W (water) stored in the heat storage tank 9.

More specifically, in this embodiment, a refrigerant temperature detecting means 21 for detecting the refrigerant temperature Tr in the heat exchanger 5 for heat collection, and a target for setting a target refrigerant temperature Trm for the refrigerant temperature Tr Refrigerant temperature setting means 22
During the cold storage heat recovery operation, the refrigerant temperature Tr and the heat storage medium temperature T
a first decompression mechanism control means for receiving the value of w and controlling the first decompression mechanism so that the refrigerant temperature Tr approaches the target refrigerant temperature Trm set by the target refrigerant temperature setting means. ing.

FIG. 2 is a refrigerant circuit diagram of the regenerative air conditioner according to this embodiment. As is apparent from FIG. 2, the compressor 2, the condenser 3, and the refrigerant condensed in the condenser 3 are depressurized. The first decompression mechanism 4 performs heat collection from the heat storage medium W during the cold storage heat recovery operation, and superheats the refrigerant to superheat the refrigerant, and is condensed by the condenser 3 and the heat collection heat exchanger 5. Second decompression mechanism 6 for depressurizing refrigerant, and evaporator 7
Are sequentially connected by the refrigerant pipe 8 to form the refrigerant circuit 1. In this embodiment, one set of the second decompression mechanism 6 and the evaporator 7 is provided for one system of the refrigerant circuit 1, but a plurality of sets of the second decompression mechanism 6 and the evaporator 7 are connected in parallel. May be.

Reference numeral 11 denotes an inverter for variably adjusting the operating capacity of the compressor 2. Since the operating capacity of the compressor 2 is obtained from the output frequency F of the inverter 11, the inverter 11 serves as operating capacity detecting means. Function. The heat exchanger 5 for heat collection of the air conditioner has a structure capable of exchanging heat with the heat storage medium W in the heat storage tank 9 which can store heat. Further, in the refrigerant circuit 1, an accumulator 10 for separating liquid refrigerant in a gas sucked into the compressor 2 is disposed upstream of the compressor 2 as an accessory device.

The regenerative air conditioner is provided with many sensors. That is, Th3 is disposed upstream of the heat-exchanger heat exchanger 5, and the temperature of the refrigerant (inlet temperature)
An inlet temperature sensor as inlet temperature detecting means for detecting T3, and Th4 is disposed at the outlet of the heat exchanger for heat collection 5 and serves as an outlet temperature detecting means for detecting the temperature (outlet temperature) T4 of the refrigerant after heat collection. The outlet temperature sensor Th1 is disposed at the air inlet of the evaporator 7, detects the room temperature Ta, and sets the set temperature Ts.
A room temperature sensor as a load detecting means for detecting an air conditioning load from a temperature difference ΔT from the temperature difference Th, a suction pipe sensor Th2 attached to a refrigerant pipe on the suction side to detect a suction pipe temperature T2, and a Thw disposed inside the heat storage tank 9. This is a heat storage medium temperature sensor as heat storage medium temperature detecting means for detecting the temperature Tw of the heat storage medium W. Further, Sp1 is disposed in a suction pipe of the compressor 2 and detects a low pressure sensor Te which is a physical state quantity of the suction refrigerant and corresponds to an evaporation pressure of the refrigerant (hereinafter, referred to as “evaporation temperature”) Te. This is a high-pressure sensor that is disposed in the pipe and detects a saturation temperature (hereinafter, referred to as “condensation temperature”) Tc corresponding to the condensation pressure of the refrigerant that is a physical state quantity of the discharged refrigerant.

Each of the sensors is connected to a controller 12 as operating means for controlling the operation of the entire apparatus. The controller 12 controls the operating state of the apparatus and the sensors Th1, Th2, Th3, Th4, Thw, Sp1,.
The valve opening of the first pressure reducing mechanism 4 is controlled in accordance with a signal from Sp2.

Next, the operation state of the regenerative air conditioner configured as described above will be described. At the time of the cold storage heat recovery operation in which the heat storage medium W (ice) in the heat storage tank 9 is melted and the cooling operation using the cold is performed, the first pressure reducing mechanism 4 and the second pressure reducing mechanism 4 are used.
The operation is performed while mutually adjusting the degree of opening of the pressure reducing mechanism 6, the refrigerant condensed in the condenser 3 is depressurized in the first pressure reducing mechanism 4, and the heat is transferred from the heat storage medium W in the heat collecting heat exchanger 5. After the heat collection, the pressure is further reduced by the second pressure reducing mechanism 6 and the evaporator 7
The refrigerant is circulated to evaporate and return to the compressor 2 for cooling.

At this time, the control of the use of cold storage heat performed by the controller 12 is as follows. That is, FIG. 3 is a flowchart showing the control contents of the controller 12. First, in step S1, the inlet temperature sensor Th3, the outlet temperature sensor Th4, and the room temperature sensor T
Inlet temperature T3 and outlet temperature T4 of the liquid refrigerant detected at h1
And values of the room temperature Ta and the operating frequency (operating capacity) F of the compressor 2 detected from the inverter 11,
After calculating the air-conditioning load from the temperature difference ΔT between the preset set temperature Ts and the room temperature Ta in step S2, the target heat collection amount ΔQs of the cold storage heat is determined in step S3. Next, in step S4, the evaporation temperature Te, the operating capacity F of the compressor 2
The refrigerant circulation amount Gr is calculated from the inlet temperature T3 and the target refrigerant temperature Trm is calculated from the refrigerant circulation amount Gr, the target heat collection amount ΔQs, and the heat storage medium temperature Tw in step S5, and the refrigerant is calculated from the inlet temperature T3 and the outlet temperature T4 in step S6. The temperature Tr is obtained. Then, a temperature deviation between the refrigerant temperature Tr and the target refrigerant temperature Trm is calculated in step S7, and the first pressure reducing mechanism 4 is controlled so that the refrigerant temperature Tr approaches the target refrigerant temperature Trm in step S8.

Step S3 of the above-mentioned flowchart constitutes a target heat extraction amount calculating means.
4 constitutes a refrigerant circulation amount detecting means for calculating the refrigerant circulation amount Gr, step S6 constitutes the refrigerant temperature detecting means 21 for calculating the refrigerant temperature Tr of the heat collecting heat exchanger 5, and step S8 designates a refrigerant circulation amount detecting means. First pressure reducing mechanism control means 23 for controlling the first pressure reducing mechanism 4 is configured. Further, the target refrigerant temperature setting means 22 is composed of the target heat extraction amount calculating means and the refrigerant circulation amount detecting function.

Here, the effect of the regenerative air conditioner of this embodiment will be described below based on comparison with a conventional regenerative air conditioner. FIG. 4 is a Mollier diagram showing a state in which all the refrigerant flows toward the heat-collecting heat exchanger 5 in the cold storage heat recovery operation of the conventional heat storage air conditioner shown in FIG. 9, (a). Is a discharge pipe of the compressor 2, (b) is an inlet pipe of the heat collecting heat exchanger 5, (c) is an outlet pipe of the heat collecting heat exchanger 5, (d) is an inlet of the evaporator 7, (e). Indicates the state of the refrigerant in each of the suction pipes of the compressor 2. In this graph, the vertical axis represents the absolute pressure, and the horizontal axis represents the enthalpy of the refrigerant. Since the capacity is represented by enthalpy difference × refrigerant circulation amount, the cooling capacity Wc is obtained by using the refrigerant circulation amount Gr as follows: Wc = (he−hd) × Gr (1)

On the other hand, in the conventional heat storage type air conditioner shown in FIG. 5, in order to suppress the amount of heat taken from the heat storage medium W, a part of the refrigerant from the condenser 3 is transferred to the branch 13 (that is, the heat collection heat). FIG. 4 is a Mollier diagram in a state where the liquid flows into the liquid exchanger 8) and the remainder flows into the liquid line 8a. (A ') is the compressor 2
(B ') is a heat exchanger for heat collection 5 inlet pipe,
(C ′) is the outlet pipe of the heat exchanger for heat collection 5, (d ′) is the inlet of the evaporator 7, (e ′) is the suction pipe of the compressor 2, and (f) is the downstream position of the junction R. , The refrigerant on the side of the heat-collecting heat exchanger 5 branched to the branch 13 flows through the path (b ′) → (c ′) → (f),
The refrigerant on the side of the liquid line 8a that did not branch to 3 is (b ′) →
It flows along the path (f). At this time, the cooling capacity Wc ′ is given by Wc ′ = (he′−hd ′) × Gr ′ where Gr ′ is the refrigerant circulation amount.

FIG. 6 is a Mollier diagram showing a state in which the valve opening control of the first pressure reducing mechanism 4 is performed to suppress the amount of heat taken from the heat storage medium W in the heat storage type air conditioner of this embodiment. is there. (G) shows the state of the refrigerant at the upstream position of the first pressure reducing mechanism 4, and the refrigerant is (g) → (b ″).
Then, heat is taken from the heat storage medium W at the saturation temperature of the pressure P1. Assuming that the amount Ws of heat collected from the heat storage medium is the refrigerant circulation amount Gr ″, Ws = A × Gr ″ × ΔT (Equation 3) is calculated. Here, A is a heat transfer area and a constant, ΔT
Is the logarithmic temperature difference between the heat storage medium W and the refrigerant temperature of the heat-collecting heat exchanger 5, which decreases as the refrigerant temperature of the heat-collecting heat exchanger 5 decreases. That is, here, the refrigerant temperature of the heat-collecting heat exchanger 5 is reduced by decreasing the refrigerant pressure of the heat-collecting heat exchanger 5 from P2 to P1.
And the temperature difference ΔT between the temperature of the heat storage medium W and the refrigerant temperature of the heat collection heat exchanger 5 is reduced to reduce the amount of heat collected from the heat storage medium W. At this time, the refrigerant capacity Wc ″ is expressed by Wc ″ = (he ″ −hd ″) × Gr ″ Equation 4.

Here, when Equations 2 and 4 are compared, (h
e "-hd")>(he'-hd'). Therefore, if the cooling capacity Wc 'is equal to the cooling capacity Wc ", Gr"<Gr', and the total refrigerant circulation amount of the refrigerant circuit is larger in the conventional regenerative air conditioner. In the refrigerant circuit of the related art, the required heat collecting capacity from the heat storage medium W becomes smaller, and the smaller the amount of refrigerant flowing to the heat collecting heat exchanger 5 becomes, the larger the total refrigerant circulation amount becomes compared to the present invention. Required. In other words, it can be said that the refrigerant circuit of the present invention can reduce the work amount, that is, the input of the compressor 2, and can more significantly reduce the power consumption.

FIG. 7 is a graph showing the relationship between the required cooling capacity and the increase in the enthalpy of the refrigerant due to the heat collection from the heat storage medium. The vertical axis indicates the required cooling capacity. The horizontal axis represents the enthalpy difference of the refrigerant that increases due to the heat collection from the heat storage medium, that is, (hb′−hd ′) and (hb ″) in FIGS. 5 and 6.
−hd ”). The changes according to the prior art and the present invention are indicated by solid lines, respectively, and the present invention obtains more heat from the heat storage medium. That is, when the cooling capacity is the same, In the conventional system, the circulation amount of the refrigerant in the refrigerant circuit is larger than in the present invention, and the work amount, that is, the input of the compressor 2 is naturally larger.

In the conventional refrigerant circuit, when the amount of the refrigerant flowing through the heat-exchanger heat exchanger 5 decreases, the flow velocity of the refrigerant flowing inside the heat-exchanger heat exchanger 5 decreases, and the condensed refrigerant falls into the piping. The flow of the refrigerant becomes unstable due to such reasons as that it becomes difficult to control the heat collection capacity,
The cooling operation itself becomes unstable. Therefore, even when the amount of heat collected from the heat storage medium W is small, it is necessary to flow the refrigerant into the heat collecting heat exchanger 5 at an unnecessarily high flow rate. On the other hand, in the present invention, the entire refrigerant flowing through the refrigerant circuit 1 flows through the heat exchanger 5 for heat collection regardless of the required amount of heat collected from the heat storage medium W, so that the condensed refrigerant does not stagnate. Therefore,
Stable cooling capacity can be obtained even in a region where the required heat collection amount (capacity) is small.

FIG. 8 is a graph showing the relationship between the required heat collection amount and the refrigerant circulation amount of the heat exchanger for heat collection. The vertical axis indicates the required heat collection amount, and the required heat collection amount is controlled in the range of X to Y. I have. The horizontal axis indicates the refrigerant circulation amount of the heat exchanger for heat collection,
As described above, the refrigerant circulation amount has a flow rate limit due to a decrease in flow velocity. (A), (B) and (C) in the figure are respectively
The points of the operating state of FIGS. 4, 5 and 6 are shown. The conventional technology is indicated by a solid line, and the amount of heat circulation is adjusted by changing the flow rate of the refrigerant circulation. Therefore, when the required heat generation amount is equal to or less than Z, the refrigerant circulation amount is equal to or less than the limit value, and the heat generation amount is controlled. Is impossible. On the other hand, in the present invention, as shown by the solid line, the heat collection amount is controlled by the temperature difference between the heat storage medium W and the refrigerant temperature of the heat collection heat exchanger 5, so that the refrigerant circulation amount does not change. Therefore, the required heat extraction can be controlled in a wide range.

In the above-described embodiment, the valve of the first pressure reducing mechanism 4 is controlled based on the temperature difference between the target refrigerant temperature Trm calculated from the temperature Tw of the heat storage medium W and the like and the refrigerant temperature Tr of the heat collecting heat exchanger 5. Although the opening was controlled, a control method that controls the valve opening of the first pressure reducing mechanism 4 based on, for example, the refrigerant pressure in the heat-collecting heat exchanger 5 is also considered to be effective. .

[0034]

As described above, in the regenerative air conditioner according to the present invention, the liquid refrigerant in the refrigerant circuit bypasses the heat exchanger for collecting heat during the cold storage heat recovery cooling operation as in the prior art. A circuit configuration in which the entire amount of the refrigerant is circulated in the order of the condenser, the heat exchanger for heat collection, and the evaporator without flowing the first heat exchanger is provided between the condenser and the heat exchanger for heat collection. The refrigerant pressure in the heat-exchanger heat exchanger is changed under the condition of “condenser pressure ≧ pressure of the heat-exchanger heat exchanger” by controlling the valve opening degree of the pressure-reducing mechanism of the heat-exchanger. By increasing or decreasing the temperature difference between the refrigerant inside and the heat storage medium, the heat collecting capacity of the heat collecting heat exchanger is controlled while the refrigerant circulation amount is kept constant. Therefore, the power consumption can be more remarkably reduced as compared with the conventional regenerative air conditioner, and the heat collecting capacity can be accurately adjusted even in a region where the required heat collecting capacity is small.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic configuration of a regenerative air conditioner according to the present invention.

FIG. 2 is a refrigerant circuit diagram of the regenerative air conditioner according to one embodiment of the present invention.

FIG. 3 is a flowchart illustrating a valve opening control operation of a first pressure reducing mechanism by a controller.

FIG. 4 is a Mollier chart showing a maximum heat collecting operation state in a conventional heat storage type air conditioner.

FIG. 5 is a Mollier chart showing a heat collection amount save operation state in the conventional heat storage type air conditioner.

FIG. 6 is a Mollier chart showing a heat collection amount save operation state in the heat storage type air conditioner of the present invention.

FIG. 7 is a graph showing a relationship between a required cooling capacity and an increase in enthalpy of the refrigerant due to heat collection from the heat storage medium.

FIG. 8 is a graph showing a relationship between a required heat extraction amount and a refrigerant circulation amount flowing through a heat extraction heat exchanger.

FIG. 9 is a schematic configuration diagram of a conventional regenerative air conditioner.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 refrigerant circuit, 2 compressor, 3 condenser, 4 first decompression mechanism, 5 heat exchanger for heat collection, 6 second decompression mechanism, 7
Evaporator, 8 refrigerant pipe, 9 heat storage tank, W heat storage medium.

Claims (1)

[Claims] 1. A compressor, a condenser, a first pressure reducing mechanism, a heat exchanger for collecting heat from a heat storage medium, a second pressure reducing mechanism,
And a refrigerant circuit formed by sequentially connecting the evaporator,
The method according to the present invention is characterized in that by controlling a valve opening degree of the first pressure reducing mechanism to change a refrigerant pressure in the heat collecting heat exchanger, the heat collecting capacity of the heat collecting heat exchanger is adjusted. Heat storage type air conditioner.