JPH05340634A - Heat storage type air conditioner - Google Patents

Abstract

PURPOSE:To obtain a compact heat reservoir having a high efficiency particularly in a cycle having an ice storage tank of a heat storage type air conditioner. CONSTITUTION:A heat storage type air conditioner has a primary side cycle communicating with a heat source side and a secondary side cycle communicating with a load side. A primary side heat exchanger 13a in a heat reservoir STR is formed of heat transfer tubes P1 and fins F1, F2 mounted perpendicularly to a longitudinal direction of the tubes P1. Heat insulators D1, D2 are mounted at free end sides of the fins F1, F2 thereby to conduct an operation in which a decrease in performance of the exchanger 13a due to icing progress at night, cold storage is suppressed to a minimum limit.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner using air as a heat source, and has a heat storage function for utilizing nighttime electric power.
And a heat storage type air conditioner having a control function thereof.

[0002]

2. Description of the Related Art Various conventional heat storage type air conditioners have already been developed, for example, refrigeration / sixth type.
There is a heat storage type air conditioner as shown in P358 of Volume 2, No. 714 (April, 1987).

The basic technique will be described with reference to FIG.
As shown in FIG. 1, the air-cooling heat pump 1 has a refrigeration cycle A in which a compressor 2, a four-way valve 3, an outdoor heat exchanger 4, an outdoor expansion valve 5, a Freon-to-brine heat exchanger 6 are sequentially connected in an annular shape.
On the other hand, a freon-to-brine heat exchanger 6, a brine-to-water heat exchanger 7, a heat storage tank 8, and a brine pump 9 are sequentially connected in an annular shape to form a brine circulation cycle B.

On the load side, the brine-to-water heat exchanger 7, the heat storage tank 8, the cold / hot water pump 10, and the indoor unit 12 are sequentially connected in an annular shape to form a cold / hot water circulation cycle C.

In this heat storage type air conditioner, during the nighttime operation, the four-way valve 3 switches the ice making operation and the heat storing operation in the refrigeration cycle A, and during the ice making operation, the refrigerant flows in the direction of the solid line arrow in the figure to perform the cooling cycle. It is formed and stored as ice around the heat transfer tube in the heat storage tank 8 in the brine circulation cycle B via the Freon-to-brine heat exchanger 6.

Further, during the heat storage operation, the refrigerant flows in the direction of the broken line in the drawing to form a heating cycle, and heat is stored as hot water in the heat storage tank 8 in the brine circulation cycle B through the CFC-to-brine heat exchanger 6 as well. .. In this case, the brine to water heat exchanger 7 is not used.

On the other hand, during the daytime operation, the cold / hot water circulation cycle C is used.
In, the cold / hot water in the heat storage tank 8 is sent to the indoor unit 12 by the cold / hot water pump 10 to perform cooling / heating.

At this time, in order to increase the efficiency of the cold / hot water circulation cycle C, a refrigeration cycle A and a brine circulation cycle B
Is operated in the cooling or heating mode to precool or preheat the cold / hot water in the cold / hot water circulation cycle C via the brine-to-water heat exchanger 7.

As described above, the surplus power energy at night is converted into heat to store the heat and the power is used in the daytime to suppress the power peak at the time of high load in the daytime and level the power usage. Is possible.

[0010]

However, in the above-mentioned conventional example, since the two heat exchangers are interposed between the heat source side and the load side, the efficiency is low, and cold / hot water is directly conveyed to the load side. Therefore, when a water leakage accident occurs, water loss to OA equipment in an office, which has been improved in OA in recent years, cannot be avoided.

Further, in the ice making operation at night, if the thickness of the ice around the heat transfer tube in the heat storage tank increases, the heat transfer rate between the refrigerant and the water decreases, so that efficient cold storage cannot be performed. Was there.

Therefore, an object of the present invention is to provide a heat storage type air conditioner having high efficiency and high safety.

[0013]

Means for Solving the Problems The technical means of the present invention for solving the above problems is to provide a heat storage tank in a heat storage type air conditioner comprising a primary side refrigeration cycle and a secondary side refrigeration cycle via a heat storage tank. Is composed of a heat transfer tube and fins installed at right angles to its length, and a primary side heat exchange section composed of a heat insulating material installed on both free end sides of the fin, and a heat transfer tube and fins. And a secondary side heat exchange section.

[0014]

The function of this technical means is as follows.

The compressor, the four-way valve, the outdoor heat exchanger, the expansion valve, the switching valve, the primary side heat exchange section of the refrigerant-refrigerant heat exchanger, and the primary side heat exchange section in the heat storage tank are connected to each other. In the secondary refrigeration cycle, by using the nighttime electric power and not using the refrigerant-refrigerant heat exchanger, by controlling the switching valve and the expansion valve,
Cool or store heat in water via a heat transfer tube in the heat storage tank.

During the cold storage operation, the amount of icing ice is larger than that of the heat transfer tube alone because the heat transfer area is increased by the fins of the primary side heat exchange section in the heat storage tank.

However, when the ice making operation is further continued, the ice thickness increases, and the thermal resistance between the refrigerant inside the heat transfer tube and the water outside the heat transfer tube increases, so that the heat transmission rate decreases significantly, and the efficiency is improved. I can't make ice.

Therefore, the progress of ice accretion on the outer surface of the primary side heat exchange section in the heat storage tank is detected by measuring the ice thickness with the ice making amount sensor, and when the ice thickness reaches a predetermined value, the four-way valve is switched. By temporarily performing the heat storage operation, the hot gas is guided to the heat storage tank to partially melt the ice layer near the outer surface of the primary side heat exchange section.

At this time, since the heat insulating material is installed on the free end side of the fins, the ice does not cover the entire circumference of the primary side heat exchange section, and after the ice is separated into the right and left sides of the heat transfer tube, the buoyancy of the ice itself. To float near the surface of the water. Then, the four-way valve is switched again to perform the ice making operation.

On the other hand, in the daytime operation, the primary side refrigeration cycle is operated in a state where the primary side heat exchange section of the heat storage tank is not used by the control of the switching valve, and the refrigerant-refrigerant heat is added in addition to the cold storage heat in the heat storage tank. The operation of the secondary side refrigeration cycle is performed in which the cooling / heating capacity in the primary side refrigeration cycle is exchanged with the refrigerant in the secondary side refrigeration cycle via the exchanger.

That is, the heat storage material and the refrigerant stored as the cold storage heat in the heat storage tank exchange heat at high speed through the finned secondary side heat exchange section in the heat storage tank, and the refrigerant is transferred to the refrigerant transfer pump. And transfers it to the indoor heat exchanger to exchange heat with the indoor air (cooling or heating).

As a result, not only heating or cooling operation can be performed in the daytime by the stored cold heat using nighttime electric power,
During night-time cold storage operation, efficient operation can be achieved with a minimum decrease in heat transfer rate due to ice accretion on the outer surface of the heat transfer tube, and load response during daytime operation is improved.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings. The same components as those of the prior art will be designated by the same reference numerals and detailed description thereof will be omitted.

FIG. 1 is a refrigeration cycle diagram of a heat storage type air conditioner according to an embodiment of the present invention. The heat storage type air conditioner of this embodiment includes an outdoor unit 11 and an indoor unit 12.

The outdoor unit 11 is a refrigerant comprising a compressor 2, a four-way valve 3, an outdoor heat exchanger 4, an expansion valve 5, a three-way valve KV1, a primary side heat exchange section 14a and a secondary side heat exchange section 14b. It is composed of a heat exchanger for refrigerant HEX, a heat storage tank STR that is filled with water 16 and includes a primary side heat exchange section 13a and a secondary side heat exchange section 13b, and a refrigerant transfer pump PM.

On the other hand, the indoor unit 12 comprises an indoor heat exchanger 17. 2 is a vertical cross-sectional view of the heat storage tank STR in FIG. 1, and FIG. 3 is the primary side heat exchange section 1 of the same.
3a is a side view, and FIG. 4 is a sectional view taken along line AA of FIG.

Primary side heat exchange parts 13a and 2 of the heat storage tank STR
As shown in FIG. 2, FIG. 3, and FIG. 4, the primary heat exchange part 13a includes a heat transfer tube P1 and two fins F1 and F2 installed at right angles to the heat transfer tube P1. And the heat insulating material D installed on both free end sides of the fins F1 and F2
1, the heat insulating material D2, and the secondary heat exchange part 13b is composed of the fin F3 and the heat transfer tube P2.

In the outdoor unit 11, the compressor 2 and
The four-way valve 3, the outdoor heat exchanger 4, and the expansion valve 5 are sequentially communicated with each other, and the three-way valve KV1 is further used to connect the primary side heat exchange section 14a of the refrigerant-refrigerant heat exchanger HEX and the heat storage tank STR. Of 1
The primary side refrigeration cycle is formed by communicating with the secondary side heat exchange section 13a in parallel.

On the other hand, the secondary side heat exchange section 1 of the STR in the heat storage tank
3b and the secondary heat exchanger 1 of the refrigerant-to-refrigerant heat exchanger HEX
4b, the reversible refrigerant transport pump PM, and the indoor heat exchanger 17 are sequentially connected to each other to form a secondary refrigeration cycle.

Next, the operation of the structure of this embodiment will be described. Table 1 shows the open / closed states of the four-way valve 3, the expansion valve 5, and the three-way valve KV1 and the working state (evaporator or condenser) of each heat exchanger in each case in this embodiment. Hereinafter, description will be made with reference to (Table 1).

[0031]

[Table 1]

First, the nighttime ice making / heat storage operation (primary refrigeration cycle) will be described. In the primary side refrigeration cycle, the heat storage tank STR operates to operate the refrigerant-refrigerant heat exchanger HE.
The three-way valve KV1 is switched so that X does not act, and the refrigerant transfer pump PM in the secondary side refrigeration cycle is stopped. The operation of the primary side refrigeration cycle in this case will be described below.

Regarding the mode of the four-way valve 3, a cooling mode is used when the discharge side of the compressor 2 and the outdoor heat exchanger 4 and the suction side of the compressor 2 and the heat storage tank STR are connected to each other. A mode in which the discharge side of the compressor 2 communicates with the heat storage tank STR and the suction side of the compressor 2 communicates with the outdoor heat exchanger 4 is defined as a heating mode.

As for the three-way valve KV1, the first mode is set so that the heat storage tank STR and the expansion valve 5 communicate with each other in the primary side refrigeration cycle, and the refrigerant-refrigerant heat exchanger HEX and the expansion valve 5 are connected.
The setting communicating with and is defined as the second mode.

Night-time ice making operation: The four-way valve 3 is set to the cooling mode, the expansion valve 5 is set to a predetermined opening, and the three-way valve KV1 is set to the first mode. At this time, the high temperature and high pressure refrigerant sent from the compressor 2 is
After being condensed in the outdoor heat exchanger 4, decompressed by the expansion valve 5 to be in a liquid or two-phase state, evaporated in the pipe of the primary side heat exchange section 13a in the heat storage tank STR, and absorbed from the water 16 ,
Return to compressor 2.

At this time, since the heat transfer area of the primary side heat exchange section 13a is increased by the fins F1 and F2, the amount of icing ice is larger than that when only the heat transfer tube is used. 1 in FIG.
The ice accretion state in the secondary side heat exchange part 13a is shown.

However, if the ice making operation is further continued, the ice thickness increases, and the thermal resistance between the refrigerant inside the heat transfer tube and the water outside the heat transfer tube increases, so the heat transfer rate drops significantly and the efficiency is improved. Since ice making cannot be performed, the progress of ice accretion on the outer surface of the primary side heat exchange section 13a in the heat storage tank is detected by measuring the ice thickness with the ice making amount sensor, and when the ice thickness reaches a predetermined value, the four-way valve By switching 3 to temporarily perform the heat storage operation, the hot gas is guided to the heat storage tank STR to partially melt the ice layer near the outer surface of the primary side heat exchange section 13a.

FIG. 5 (b) shows an ice separation state in the primary side heat exchange section 13a. As shown in FIG. 5 (b), the ice does not cover the entire circumference of the primary side heat exchange section 13 a due to the heat insulating material D 1 and the heat insulating material D 2 installed on the free end side of the fin, and the ice does not cover the heat transfer tube P 1 After separating to the left and right, it floats near the water surface by the buoyancy of the ice itself.

Then, the four-way valve 3 is switched again to perform the ice making operation. Nighttime heat storage operation: The four-way valve 3 is in the heating mode, the expansion valve 5 is in a predetermined opening degree, and the three-way valve KV1 is in the first mode. At this time, the high-temperature and high-pressure refrigerant sent from the compressor 2 is condensed in the pipe of the primary side heat exchange section 13a in the heat storage tank STR and radiates heat to the water 16, and is then decompressed by the expansion valve 5 to form liquid or liquid. It becomes a two-phase state, evaporates in the pipe of the outdoor heat exchanger 4, absorbs heat from the outside, and then returns to the compressor 2.

As a result, as in the nighttime ice making operation in the heat storage tank STR, the heat transfer area is increased by the fins F1 and F2, so that efficient heat storage can be performed.

Next, the daytime operation will be described. In this case, the heat is stored in the heat storage tank STR (heat storage), but in the primary side refrigeration cycle, the three-way valve KV1 is used as the first mode to evaporate the secondary side heat exchange section 14a of the refrigerant-refrigerant heat exchanger HEX. It operates as a condenser (condenser).

At the same time, in the secondary side refrigeration cycle, the secondary side heat exchange section 14b of the refrigerant-to-refrigerant heat exchanger HEX is operated to operate.

In this state, the refrigerant in the secondary side refrigeration cycle is sent to the secondary side heat exchange section 13b in the heat storage tank STR by the refrigerant transfer pump PM, and the secondary side heat exchange section 13b is connected to the fin F3. , And the heat transfer pipe P2, a large heat transfer area can be obtained, and the water in the heat storage tank STR can be efficiently used.
Heat exchange with 6 at high speed.

During cooling, the refrigerant flows as shown by the arrow a in FIG. 1, and the refrigerant cooled in the secondary side heat exchange section 13b in the heat storage tank STR is further cooled by the refrigerant-refrigerant heat exchanger HEX 2.
It is sent to the secondary side heat exchange section 14b and cooled by heat exchange with the secondary side heat exchange section 14a of the refrigerant-refrigerant heat exchanger HEX in the primary side refrigeration cycle to become a liquid refrigerant, and then the indoor side heat exchanger. The refrigerant is sent to 17, where it exchanges heat with the indoor air to cool the indoor air, and the refrigerant itself becomes a high-temperature gas refrigerant and returns to the secondary side heat exchange section 13b in the heat storage tank STR.

Further, during heating, the refrigerant flows as shown by the arrow b in FIG. 1, and the refrigerant heated in the secondary heat exchange section 13b in the heat storage tank STR is further cooled by the refrigerant-refrigerant heat exchanger HE.
It is sent to the secondary side heat exchange section 14b of X and is sent to the secondary side heat exchange section 14 of the refrigerant-refrigerant heat exchanger HEX in the primary side refrigeration cycle.
It is heated by heat exchange with a to become a gas refrigerant.

Thereafter, the reversible refrigerant transfer pump PM is sent to the indoor heat exchanger 17, where it exchanges heat with the indoor air to heat the indoor air, and the refrigerant itself becomes a low-temperature liquid refrigerant and is reversible. The action of returning to the refrigerant transport pump PM is repeated.

In this way, even when the indoor load during the daytime is large, it is possible to cope with it, and the cooling / heating operation in the indoor unit is performed.

As described above, in the above embodiment, in the heat storage type air conditioner consisting of the primary side refrigeration cycle and the secondary side refrigeration cycle via the heat storage tank, the heat storage tank STR is composed of the heat transfer pipe P1 and its length. Fins F1 and F2 installed at right angles to the direction
And a heat exchanger D1 and D2 installed on both free end sides of the fins F1 and F2, and a heat exchanger 13a including a heat transfer tube P2 and a fin F3. It is composed of 13b.

As a result, not only the cooling (heating) operation can be performed by the cold storage (heat storage) using the night power, but also the fins F1, F2, F3 in the heat storage tank STR, and the heat insulating material D.
By the primary side heat exchange unit 13a with D1 and D2, during the nighttime cold storage operation, efficient cold storage can be performed while minimizing the decrease in the heat transfer rate due to the progress of icing on the outer surface of the heat transfer tube.

Further, the secondary heat exchange section 13b with fins in the heat storage tank STR makes it possible to take out cold (heat storage) at a high speed, and the load response is improved.

[0051]

As described above, according to the present invention, in the heat storage type air conditioner comprising the primary side refrigeration cycle and the secondary side refrigeration cycle with the heat storage tank, the heat storage tank is connected to the heat transfer tube and its longitudinal direction. A primary side heat exchange section composed of fins installed at right angles to and heat insulating materials installed on both free end sides of the fins,
And a secondary-side heat exchange section including heat transfer tubes and fins.

As a result, not only the cooling / heating operation can be performed at a low operating cost by the cold storage heat using night power,
The fins in the heat storage tank and the primary-side heat exchange section with a heat insulating material enable efficient cold storage with a minimum reduction in the heat transfer rate due to the progress of icing on the outer surface of the heat transfer tubes during nighttime cold storage operation.

Further, the secondary side heat exchanging portion with fins in the heat storage tank can take out the cold stored heat at a high speed, and the load responsiveness is improved.

[Brief description of drawings]

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

FIG. 2 is a sectional view of a heat exchanger in a heat storage tank according to an embodiment of the present invention.

FIG. 3 is a side view of the primary side heat exchange section in the heat storage tank according to the embodiment of the present invention.

4 is a sectional view taken along line AA in FIG.

FIG. 5 (a) is a diagram showing an ice accretion state in the primary side heat exchange section in the heat storage tank during the nighttime cold storage operation (b) Ice separation state in the primary side heat exchange section in the heat storage tank during the nighttime cold storage operation Cross section showing

FIG. 6 is a refrigeration system diagram of a heat pump type air conditioner showing a conventional example.

[Explanation of symbols]

 2 Compressor 3 Four-way valve 4 Outdoor heat exchanger 5 Expansion valve 13a Primary heat exchange part of heat storage tank 13b Secondary heat exchange part of heat storage tank 14a Primary heat exchange part of refrigerant-refrigerant heat exchanger 14b Secondary side heat exchange part of refrigerant-to-refrigerant heat exchanger 17 Indoor side heat exchanger STR Heat storage tank P1, P2 Heat transfer pipes F1, F2, F3 Fins D1, D2 Insulation material HEX Refrigerant-to-refrigerant heat exchanger PM Refrigerant transfer pump KV1 Three-way valve

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Kozo Suzuki 1-3-1, Uchisaiwaicho, Chiyoda-ku, Tokyo Tokyo Electric Power Co., Inc. (72) Yoshihide Sugita 1-3-1, Uchisaiwai-cho, Chiyoda-ku, Tokyo Kyoden Co., Ltd.

Claims (1)

[Claims] 1. A compressor, a four-way valve, an outdoor heat exchanger, an expansion valve, and a switching valve are connected in series, and a primary side heat exchange section and a secondary side heat exchange section are provided. Refrigerant-to-refrigerant heat exchangers, primary heat exchange parts of a heat storage tank having a primary side heat exchange part and a secondary side heat exchange part are arranged in parallel, and the flow path of the refrigerant is switched by the switching valve. The primary side refrigeration cycle made possible, the secondary side heat exchange section in the heat storage tank, and the refrigerant-refrigerant heat exchanger 2
A fin having a secondary heat exchange section, a refrigerant transfer pump, and a secondary refrigeration cycle in which an indoor heat exchanger is annularly connected, and the heat storage tank is installed at right angles to the heat transfer tube and its length direction. Reservoir type air conditioner composed of a primary side heat exchange part composed of a heat insulating material installed on both free end sides of the fin, and a secondary side heat exchange part composed of a heat transfer tube and fins. ..