JP2002061896A - Ice thermal storage type air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ice thermal storage type air conditioner which realizes the improvement of a cooling capacity. SOLUTION: The ice thermal storage type air conditioner having a thermal storage tank 15 in which ice is accommodated comprises a heat transfer part 46 for a peak shift operation having heat transfer pipes 40 for shift (heat transfer pipes for a peak shift operation), heat transfer pipes for cutting (heat transfer pipes for a peak cutting operation) 41 and a heat transfer part 47 for a peak cutting operation provided with a stop valve (valve) SV4 provided in the upstream side of the heat transfer pipes 41 for cutting. The heat transfer part 46 for a peak shift operation is connected in parallel with the heat transfer part 47 for a peak cutting operation and they are accommodated in the thermal storage tank 15.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ice storage type air conditioner for producing ice with nighttime electric power and using it for cooling.

[0002]

2. Description of the Related Art Conventionally, an ice storage type air conditioner (ice storage type air conditioner) shown in FIG. 7 has been provided. In FIG. 7, 1 is an ice storage air conditioner, 2 is an indoor heat exchanger, 3 is an outdoor heat exchanger, 4 is a liquid pipe through which a liquid refrigerant flows, and 5 is a gas through which a gas refrigerant flows. Tube,
The refrigerant flows in the liquid pipe 4 and the gas pipe 5 and is circulated between the indoor heat exchanger 2 and the outdoor heat exchanger 3. Reference numeral 6 denotes a compressor, and the refrigerant is compressed by the compressor 6 in the middle of the circulation path. The discharge pipe 7 of the compressor 6 is connected to a four-way valve 8 interposed in the middle of the gas pipe, and the suction pipe 9 of the compressor 6 is connected to an accumulator 10.
Is connected to the four-way valve 8 via a. When the four-way valve 8 is off, the compressor 6, the outdoor heat exchanger 3, the indoor heat exchanger 2, and the accumulator 10 are sequentially connected. When the four-way valve 8 is on, the compressor 6, the indoor heat exchanger The exchanger 2, the outdoor heat exchanger 3, and the accumulator 10 are sequentially connected.

The reference numeral 15 denotes a heat storage tank 1 containing water.
5 A heat transfer tube 16 immersed in water is stored in the heat storage tank 15.
Is housed. One end of the heat transfer tube 16 is connected to the gas pipe 5 via a pipe 16a, and the other end is connected between the outdoor heat exchanger 3 and the four-way valve 8 via a pipe 16b. . Further, a pipe 18 for connecting the pipe 16a to the liquid pipe 4 and a pipe 19 for connecting the pipe 16b to the liquid pipe 4 are provided. The pipe 19 branches on the liquid pipe 4 side into a pipe 19a and a pipe 19b. In the figure, SV1, SV2,
SV3, SV5, SV6, SV7, SV8 are stop valves, 21, 22, 23 are expansion valves, and 25a to 25a.
h is a throttle, and 32a to 32i are check valves.

[0004] FIG. 8 shows the power consumption over time of the conventional ice regenerative air conditioner constructed as described above. In the cooling operation of the present ice regenerative air conditioner, a heat storage operation for freezing water in the heat storage tank 15 is performed by using electric power at night, and cooling is performed by using the ice during daytime. Specifically, compared to the conventional power consumption indicated by the dashed line in the figure, peak shift operation that reduces overall power consumption during air conditioner operation, and drastic reduction in power consumption especially during periods of high power consumption A peak cut operation is performed. FIG. 9 shows the open / close state of each stop valve and the flow of the refrigerant during the peak shift operation and FIG. 10 during the peak cut operation. In the drawing, the thick line indicates that the refrigerant is flowing in the pipe. At the time of the peak shift operation, the refrigerant which has been compressed by the compressor 6 to become a high-temperature and high-pressure gas is sent from the four-way valve 8 to the outdoor heat exchanger 3 as shown in FIG. Then, it is sent to the liquid pipe 4, flows into the heat transfer pipe 16 via the pipes 19 b and 16 b, and is cooled by the ice in the heat storage tank 15. It is further throttled by the expansion valve 21 and the like and sent to the indoor heat exchanger 2. The refrigerant that has absorbed heat in the indoor heat exchanger 2 to become a gas is:
The gas passes through the gas pipe 5 and the four-way valve 8 and is sent to the compressor 6 again.

During peak-cut cooling, as shown in FIG. 10, the refrigerant which has been compressed by the compressor 6 and has become a high-temperature and high-pressure gas flows into the heat transfer pipe 16 from the four-way valve 8, and is stored in the heat storage tank 15. Condensed by ice to become liquid refrigerant. It is further throttled by the expansion valve 21 and the like and sent to the indoor heat exchanger 2. The refrigerant that has absorbed heat in the indoor heat exchanger 2 to become a gas is supplied to the gas pipe 5,
It passes through the four-way valve 8 and is sent to the compressor 6 again. During the heat storage operation (when ice making is performed), the refrigerant that has been compressed by the compressor 6 to become a high-temperature and high-pressure gas is sent from the four-way valve 8 to the outdoor heat exchanger 3. The refrigerant that has radiated heat in the outdoor heat exchanger 3 and has become a liquid is throttled by the expansion valve 22,
It flows into the heat transfer tube 16 via the pipe 16b, and absorbs heat from water and evaporates. At this time, the water in the heat storage tank 15 is cooled to make ice. The refrigerant that has absorbed heat in the heat storage tank 15 and turned into gas passes through the gas pipe 5 and the four-way valve 8 and is sent to the compressor 6 again.

[0006]

In the conventional ice regenerative air conditioner, when the load is large during the peak shift operation before the peak cut operation, the ice in the heat storage tank 15 is melted more than expected. was there. Therefore, there is a problem that the refrigerant in the heat transfer tube 16 is not sufficiently cooled during the peak cut operation, and as a result, a sufficient power reduction effect cannot be obtained. Further, when the ice in the heat storage tank 15 rapidly melts during the peak cut operation, water surrounds the heat transfer tube as shown in FIG.
The outer ice remains unmelted. For this reason, there has been a problem that the ability to rapidly cool the refrigerant in the heat transfer tube is reduced.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an ice regenerative air conditioner that improves the cooling capacity.

[0008]

According to a first aspect of the present invention, a heat transfer tube is provided in a heat storage tank containing water, and ice is stored in the heat storage tank by the heat transfer tube using nighttime electric power. In the ice regenerative air conditioner that makes and stores heat, and cools using this heat during the daytime, the heat transfer tube is divided into a heat transfer tube for peak shift and a heat transfer tube for peak cut, and these heat transfer tubes are arranged. The heat transfer tube for peak cut and the heat transfer tube for peak cut are connected in parallel to the refrigerant circuit, and the heat transfer tube for peak cut is capable of circulating the refrigerant independently of the heat transfer tube for peak shift. It is characterized by being.

In this ice regenerative air conditioner, the heat transfer tube for peak cutting can circulate the refrigerant independently of the heat transfer tube for peak shift. Therefore, during the peak shift operation, by stopping the supply of the refrigerant to the peak cut heat transfer tube, it is possible to keep the ice around the peak cut heat transfer tube from melting. During the peak cut operation, the refrigerant may be introduced into both the peak cut heat transfer tube and the peak shift heat transfer tube, or the refrigerant may be introduced only into the peak cut heat transfer tube. The positional relationship between the peak shift heat transfer tube and the peak cut heat transfer tube is not particularly limited.

According to a second aspect of the present invention, in the ice regenerative air conditioner according to the first aspect, the peak shift heat transfer tube is disposed below the peak cut heat transfer tube. And

[0011] In this ice regenerative air conditioner, the water heated around the peak shift heat transfer tube convects and melts the ice around the upper peak cut heat transfer tube from the outside.
Since the water itself is cooled, a rise in water temperature around the peak shift heat transfer tube is prevented.

According to a third aspect of the present invention, in the ice regenerative air conditioner of the first aspect, the peak shift heat transfer tube and the peak cut heat transfer tube are provided in multiple stages in the vertical direction, respectively. The heat transfer tubes for peak shift and the heat transfer tubes for peak cut are arranged alternately in the vertical direction at least in the lower part of the tank.

[0013] In this ice regenerative air conditioner, during the peak shift operation, the ice around the peak shift heat transfer tube is melted into water, and this water is interposed between the peak shift heat transfer tubes. Thaw the ice around the outside from outside. The heat transfer tubes for peak shift and the heat transfer tubes for peak cut may be alternately arranged one by one, or one or more tubes may be alternately arranged for each set.

According to a fourth aspect of the present invention, in the ice regenerative air conditioner of the third aspect, the peak shift heat transfer tube is provided at a lowermost portion of the heat storage tank. I do.

In this ice regenerative air conditioner, the ice at the bottom of the heat storage tank melts during the peak shift operation, so that the ice around the peak cut heat transfer tube is melted from below and outside.

According to a fifth aspect of the present invention, a heat transfer tube is provided in a heat storage tank containing water, and ice is formed in the heat storage tank by the heat transfer tube using nighttime electric power to store heat. In an ice regenerative air conditioner that cools by utilizing this heat storage during daytime, the heat transfer tubes are divided into a peak shift heat transfer tube and a peak cut heat transfer tube, and the heat transfer tubes are divided into a peak shift heat transfer tube and a peak cut heat transfer tube. Heat transfer tubes are connected in parallel to the refrigerant circulation circuit, and a valve is provided to allow the refrigerant to circulate independently of the peak shift heat transfer tubes and the peak cut heat transfer tubes. Features.

In this ice regenerative air conditioner, the peak shift heat transfer tube and the peak cut heat transfer tube can circulate the refrigerant independently of each other. Therefore, during the peak shift operation, by stopping the supply of the refrigerant to the peak cut heat transfer tube, it is possible to keep the ice around the peak cut heat transfer tube from melting. During the peak cut operation, the refrigerant may be introduced into both the peak cut heat transfer tube and the peak shift heat transfer tube, or the refrigerant may be introduced only into the peak cut heat transfer tube. In addition, during cooling heat storage (ice making) operation, the size of ice formed around both heat transfer tubes can be controlled by controlling the introduction of the refrigerant into the peak shift heat transfer tubes and the peak cut heat transfer tubes, respectively. . The positional relationship between the peak shift heat transfer tube and the peak cut heat transfer tube is not particularly limited.

According to a sixth aspect of the present invention, in the ice regenerative air conditioner according to the fifth aspect, the ice making state on each of the heat transfer tubes is provided on the side of the peak shift heat transfer tube and the peak cut heat transfer tube. A sensor for monitoring is provided, and the valve is controlled to open and close by the sensor.

In this ice regenerative air conditioner, the size of the ice formed around the peak shift heat transfer tube and the peak cut heat transfer tube is detected by the sensor, so that the size of the ice is controlled. .

[0020]

Next, embodiments of the present invention will be described with reference to the drawings. Note that the same components as those in the related art are denoted by the same reference numerals, and description thereof is omitted. As shown in FIG. 1, a heat transfer tube for peak shift (hereinafter, referred to as shift heat transfer tube) 40 and a heat transfer tube for peak cut (hereinafter, referred to as cut heat transfer tube) 41 are accommodated in the heat storage tank 15. Have been. From the pipe 19, pipes 42 and 43 are branched, and these pipes 42 and 43 pass through distributors 44 and 45, respectively, and a plurality of heat transfer tubes (shift heat transfer tube 4).
0, it is branched into a heat transfer tube for cutting 41). As shown in the figure, the heat transfer tubes 40 and 41 extend in the horizontal direction and are arranged side by side in the vertical direction. A plurality of heat transfer tubes 41 for cutting are arranged between the heat transfer tubes 40 for shift. The pipe 43 is provided with a stop valve SV4 (valve), and the pipe 42 is provided with a stop valve SV9 (valve). The shift heat transfer tube 40, the distributor 44, and the stop valve SV9 constitute a peak shift heat transfer portion 46, and the cut heat transfer tube 41, the distributor 45, and the stop valve SV4 constitute a peak cut heat transfer portion 47. I have. As shown in FIG. 2, at least one of the shift heat transfer tube 40 and the cut heat transfer tube 41 is provided with a temperature sensor 48 near the heat transfer tubes 40 and 41.
The size of ice made around 41 can be detected. The detection output of the temperature sensor 48 is input to a control unit (not shown), and the control unit determines whether the stop valve SV4
And SV9. The shift heat transfer tubes 40 and the cut heat transfer tubes 41 merge again downstream,
It is connected to a gas pipe 5 via a stop valve 5.

Next, the flow of the refrigerant during the peak shift operation and the peak cut operation will be described. 3 and 4
In addition, each stop valve SV1 to SV9 during both operations
And the flow of the refrigerant. During the peak shift operation, as shown in FIG.
Is closed, and the refrigerant flows only into the shift heat transfer tube 40. Then, the refrigerant is cooled by ice around the shift heat transfer tube 40 and introduced into the downstream indoor heat exchanger 2. During the peak cut operation, as shown in FIG. 4, the stop valve SV4 is opened, and the refrigerant is introduced into both the cut heat transfer tube 40 and the shift heat transfer tube 41. After being cooled by the ice in the heat storage tank 15, the refrigerant is introduced into the downstream indoor heat exchanger 2. The other parts of the flow of the refrigerant are the same as in the conventional example shown in FIGS. 9 and 10, respectively. By opening and closing stop valve SV4 in this manner, the ice around cut heat transfer tube 41 is not melted during the peak shift operation, and the refrigerant can be sufficiently cooled during the peak cut operation. Furthermore, at the time of the peak shift operation, the ice around the shift heat transfer tube 40 is melted to form water, and the water melts the ice around the cut heat transfer tube 41 from the outside and the water itself is cooled. Heat transfer tube 40,
The cooling capacity of the refrigerant in 41 is improved.

Next, the heat storage operation will be described. FIG. 5 shows the flow of each stop valve and the refrigerant during this operation.
As described above, in this example, the heat transfer tubes are divided into the shift heat transfer tubes 40 and the cut heat transfer tubes 41. For this reason, the state of melting of the ice around the heat transfer tubes 40 and 41 after the end of daytime cooling is different. For example, as shown in FIG. 6 (a), the ice around the heat transfer tube 41 for cutting is all melted, but ice in a hollow state may remain around the heat transfer tube 40 for shift. When the cutting heat transfer tube 41 and the shift heat transfer tube 40 are made in the same manner in this state, ice growth around the shift heat transfer tube 40 is hindered as shown in FIG. Ice continues to grow around the heat transfer tube 41, and the ice formation state of both becomes unbalanced. As a result, there has been a problem that the heat storage tank 15 is damaged due to excessive growth of ice, or a cooling effect due to ice during peak shift or peak cut operation is reduced due to insufficient growth. In this example, the stop pipes SV9 and SV4 are interposed in the shift pipe 42 and the cut pipe 43, respectively, so that such imbalance can be prevented.

More specifically, first, the stop valve SV4 and the stop valve SV9 are opened, and the growth of ice is monitored by the temperature sensors 48 provided near the shift heat transfer tube 40 and the cut heat transfer tube 41. While making ice (heat storage). Then, when one of the ice of the shift heat transfer tube 40 and the cut heat transfer tube 41 grows to a predetermined size, the control unit closes the corresponding stop valve SV9 (SV4) and the refrigerant flows into the heat transfer tube 40 (41). Prevent inflow. In the other heat transfer tube 41 (40), heat is similarly stored until the ice grows to a predetermined size. As described above, by independently controlling each of the stop valves SV9 and SV4, the shift heat transfer tube 40 and the cut heat transfer tube 4 are controlled.
1 can eliminate the imbalance of heat storage.

In the above embodiment, as means for monitoring the growth of ice, a limit switch or an ice pressure sensor may be used in addition to the temperature sensor 48. At least one of the shift heat transfer tubes 40 may be arranged at the lowermost part of the heat storage tank 15. In this case, since the ice at the bottom in the heat storage tank 15 is melted during the peak shift operation, the ice around the heat transfer tube 41 for peak cut is melted from below and outside. Since the water itself is cooled, a rise in water temperature in the heat storage tank 15 is prevented, and a decrease in heat exchange efficiency is prevented. Alternatively, the shift heat transfer tubes 40 may be arranged at the bottom of the heat storage tank 15 and the cut heat transfer tubes 41 may be arranged above them. In this case, when the refrigerant is circulated through the shift heat transfer tube 40 in the heating heat storage (at night, the water in the heat storage tank is heated and used for daytime heating), the heating efficiency of the water is reduced because the heated water convects. improves. Further, when the shift heat transfer tubes 40 and the cut heat transfer tubes 41 are alternately arranged vertically, the number thereof is not limited to the above example. For example, they may be alternately arranged one by one, or one or a plurality may be alternately arranged for each set as a set. In this example, the heat transfer tubes are divided into two, that is, the shift heat transfer tubes 40 and the cut heat transfer tubes 41. However, the heat transfer tubes may be further divided and the ratio between the shift heat transfer tubes and the cut heat transfer tubes may be appropriately changed. You may be able to. For example, it is possible to change the percentage of ice used for peak cutting by dividing the heat transfer tube into three and switching one of them to one of the shift heat transfer tube and the cut heat transfer tube Becomes

[0025]

As described above, the present invention has the following effects. According to the ice regenerative air conditioner of the first aspect, during the peak shift operation, the supply of the refrigerant to the peak cut heat transfer tube is stopped so that the ice around the peak cut heat transfer tube is not melted. Can be kept. Therefore, the refrigerant can be efficiently cooled during the peak cut operation, and the cooling capacity is improved. According to the ice regenerative air conditioner of claim 2,
Water heated around the peak shift heat transfer tube rises to melt the ice of the peak cut heat transfer tube from the outside, so that the heat exchange efficiency is improved. According to the ice regenerative air conditioner according to the third aspect, during the peak shift operation, the ice around the peak shift heat transfer tube is melted into water, and this water is cut by the peak shift heat transfer tube. Melt the ice around the heat transfer tube from outside. Therefore, a rise in the temperature of water is prevented, and a decrease in heat exchange efficiency is prevented. According to the ice regenerative air conditioner of the fourth aspect, the ice at the bottom in the heat storage tank melts during the peak shift operation, so that the ice around the peak cut heat transfer tube is melted from below and outside. Therefore, a rise in the temperature of water is prevented, and a decrease in heat exchange efficiency is prevented. Claim 5
According to the ice regenerative air conditioner described in (1), during the peak shift operation, the supply of the refrigerant to the peak cut heat transfer tube is stopped so that the ice around the peak cut heat transfer tube is not melted. be able to. Therefore, the refrigerant can be efficiently cooled during the peak cut operation, and the cooling capacity is improved. Further, by controlling the introduction of the refrigerant into the heat transfer tube for peak shift and the heat transfer tube for peak cut, respectively, it is possible to control the size of the ice formed around both the heat transfer tubes. According to the ice storage type air conditioner of the sixth aspect, the size of ice formed around the peak shift heat transfer tube and the peak cut heat transfer tube can be detected by the sensor.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a refrigerant circuit diagram in an ice storage type air conditioner shown as one embodiment of the present invention.

FIG. 2 is a diagram showing a cross-sectional view of a heat transfer tube included in the ice regenerative air conditioner and an arrangement of a temperature sensor.

FIG. 3 is a diagram showing a flow of a refrigerant during a peak shift operation of the ice storage type air conditioner.

FIG. 4 is a diagram illustrating a flow of a refrigerant during a peak cut operation of the ice regenerative air conditioner.

FIG. 5 is a diagram showing a flow of a refrigerant during a heat storage operation of the ice storage air conditioner.

6 (a) is a diagram showing the state of ice after cooling is completed, and FIG. 6 (b) is a diagram showing ice making using a heat transfer tube for a peak shift operation and a heat transfer tube for a peak cut operation. It is a figure which shows the imbalance state of ice growth when it is assumed that it was not performed independently.

FIG. 7 is a schematic diagram of a refrigerant circuit diagram in a conventional ice storage type air conditioner.

FIG. 8 is a diagram showing a relationship between power consumption and time in the ice storage type air conditioner.

FIG. 9 is a diagram illustrating a flow of a refrigerant during a peak shift operation of a conventional ice regenerative air conditioner.

FIG. 10 is a diagram showing a flow of a refrigerant during a peak cut operation of the conventional ice storage air conditioner.

FIG. 11 is a cross-sectional view showing a state of ice and water around a heat transfer tube in a conventional ice storage air conditioner.

[Explanation of symbols]

 15 Heat storage tank 40 Peak shift heat transfer tube 41 Peak cut heat transfer tube 46 Peak shift operation heat transfer unit 47 Peak cut operation heat transfer unit 48 Temperature sensor SV4, SV9 Stop valve (valve)

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tadashi Fujisaki 1 Nagoya Research Laboratory, Nagoya-shi, Aichi Prefecture, Nagoya Laboratory, Mitsubishi Heavy Industries, Ltd. (72) Inventor Harunobu Minakami Iwazuka-cho, Nakamura-ku, Nagoya-shi No. 1 Takamichi F-term in Nagoya Research Laboratory, Mitsubishi Heavy Industries, Ltd. (Reference) 3L060 AA08 CC05 CC19 DD01 EE09 3L092 TA09 TA16 UA02 UA31 UA34 VA08 WA13 XA00 XA28 YA14

Claims (6)

[Claims] 1. A heat transfer tube is provided in a heat storage tank containing water, and ice is formed in the heat storage tank by the heat transfer tube using night power to store heat, and the heat storage is used during the day. In the ice regenerative air conditioner for cooling, the heat transfer tube is divided into a heat transfer tube for peak shift and a heat transfer tube for peak cut, and the heat transfer tube for peak shift and the heat transfer tube for peak cut are provided in a refrigerant circulation circuit. And the peak cut heat transfer tube is capable of circulating a refrigerant independently of the peak shift heat transfer tube. 2. The ice regenerative air conditioner according to claim 1, wherein the peak shift heat transfer tube is disposed below the peak cut heat transfer tube. apparatus. 3. The ice regenerative air conditioner according to claim 1, wherein the peak shift heat transfer tube and the peak cut heat transfer tube are each provided in multiple stages in a vertical direction, and at least a lower portion of the heat storage tank includes: The heat storage type air conditioner according to claim 1, wherein the heat transfer tubes for peak shift and the heat transfer tubes for peak cut are alternately arranged in a vertical direction. 4. The ice regenerative air conditioner according to claim 3, wherein the peak shift heat transfer tube is arranged at a lowermost part of the heat storage tank. . 5. A heat transfer tube is disposed in a heat storage tank containing water, and ice is formed in the heat storage tank by the heat transfer tube using nighttime electric power to store heat, and the heat storage is used during the day. In the ice regenerative air conditioner for cooling, the heat transfer tube is divided into a heat transfer tube for peak shift and a heat transfer tube for peak cut, and the heat transfer tube for peak shift and the heat transfer tube for peak cut are provided in a refrigerant circulation circuit. Characterized by being provided in parallel with each other, and provided with valves capable of independently circulating a refrigerant for the peak shift heat transfer tube and the peak cut heat transfer tube, respectively. Harmony equipment. 6. The ice storage type air conditioner according to claim 5, wherein a sensor for monitoring an ice making state on each of the heat transfer tubes is provided on the side of the peak shift heat transfer tube and the peak cut heat transfer tube. An ice regenerative air conditioner, wherein the valve is controlled to open and close by the sensor.