JP3297467B2 - Thermal storage type air conditioner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art Conventional regenerative air conditioners have already been developed in various ways.
There is a regenerative air conditioner as shown in Vol. 2, No. 714 (April 1987), p.

[0003] The basic technology is described in FIG.
As shown in FIG. 1, the air-cooled heat pump 1 includes a compressor 2, a four-way valve 3, an outdoor heat exchanger 4, an outdoor expansion valve 5, and a CFC-to-brine heat exchanger 6 which are sequentially connected in a ring to form a refrigeration cycle A.
On the other hand, a CFC-brine heat exchanger 6, a brine-water heat exchanger 7, a heat storage tank 8, and a brine pump 9 are sequentially connected in a ring to form a brine circulation cycle B.

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

In this regenerative air conditioner, during the night operation, the four-way valve 3 switches between ice making operation and heat storage operation in the refrigeration cycle A. During the ice making operation, the refrigerant flows in the direction of the solid line arrow in FIG. Is formed,
The refrigerant is stored as ice around the heat transfer tubes in the heat storage tank 8 in the brine circulation cycle B via the CFC-brine heat exchanger 6.

During the heat storage operation, the refrigerant flows in the direction of the broken line in FIG. 4 to form a heating cycle, and heat is stored as hot water in the heat storage tank 8 in the brine circulation cycle B via the CFC-brine heat exchanger 6. You. in this case,
The brine-to-water heat exchanger 7 is not used.

On the other hand, in the daytime operation, the cold / hot water circulation cycle C
Then, the cold and hot water in the heat storage tank 8 is sent to the indoor unit 12 by the cold and hot water pump 10 to perform cooling and heating. At this time, the refrigeration cycle A and the brine circulation cycle B are operated in the cooling or heating mode in order to increase the efficiency in the cooling / heating water circulation cycle C, and the cooling / heating water circulation cycle C is operated via the brine / water heat exchanger 7. Pre-cooling or pre-heating of cold and hot water.

As described above, by converting surplus power energy during the night into heat and storing the heat, and using the power during the day, power peaks at high load times during the day are suppressed, and power usage is leveled. Is possible.

[0009]

However, in the above-mentioned prior art, the efficiency is low because two heat exchangers are interposed between the heat source side and the load side, and the cold and hot water is directly conveyed to the load side. Therefore, in the event of a water leak accident, there has been a disadvantage that water damage to OA equipment in an office, which has recently progressed to OA, is inevitable.

Accordingly, an object of the present invention is to provide a high-efficiency, high-security regenerative air conditioner.

[0011]

The technical solution of the present invention for solving the above-mentioned problems is to provide a heat storage tank for a heat storage type air conditioner comprising a primary refrigeration cycle and a secondary refrigeration cycle via a heat storage tank. The heat exchanger inside is composed of two or more types of heat transfer tubes with different tube diameters connected in parallel, and a heat transfer tube with a small diameter is located at the center of a group of large diameter heat transfer tubes arranged in an equilateral triangle. It is arranged to do.

[0012]

The operation of this technical means is as follows.

A compressor, a four-way valve, an outdoor heat exchanger, an expansion valve, a first switching valve, a primary heat exchange part of a refrigerant-to-refrigerant heat exchanger, and a primary heat exchange part in a heat storage tank are communicated. In the primary refrigeration cycle, the first switching valve is switched to use the heat exchanger of the heat storage tank by switching the second switching valve without using the refrigerant-to-refrigerant heat exchanger, and the expansion valve is set to the predetermined position. And the cold storage or heat storage operation is performed at night using inexpensive nighttime electric power.

Thus, the heat storage material is stored or cooled in the water as the heat storage material via the heat exchanger tubes in the heat storage tank having different diameters.

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

That is, water and refrigerant stored as cold storage heat in the heat storage tank exchange heat via a heat exchanger in the heat storage tank.
The refrigerant is conveyed to the indoor heat exchanger by a refrigerant conveying pump to exchange heat (cooling or heating) with the indoor air.

Therefore, heating or cooling operation can be performed in the daytime by the cold storage heat using the nighttime electric power. In particular, in the case of the cooling operation, the ice accumulates around the heat transfer tubes having different diameters of the heat exchangers in the heat storage tank in the night ice making operation.

At this time, the heat transfer tubes having a small diameter are arranged at the center of the heat transfer tube group having a large diameter arranged in an equilateral triangle shape. The proportion of ice in the tank volume can be increased, and an efficient ice making operation can be performed, and the responsiveness to the indoor heat load increases.

[0019]

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 are denoted by the same reference numerals, and detailed description thereof will be omitted.

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

The outdoor unit 11 includes a compressor 2, a four-way valve 3, an outdoor heat exchanger 4, an expansion valve 5, a three-way valve KV1, a refrigerant comprising a primary heat exchange section 14a and a secondary heat exchange section 14b. A heat storage tank STR including a heat exchanger HEX for the refrigerant, a three-way valve KV3, a heat exchanger 13 in a heat storage tank STR filled with water 16 as a heat storage material, a three-way valve KV4, and a refrigerant transfer pump P
M.

The indoor unit 12 includes an indoor heat exchanger 17
It is composed of FIG. 2 shows the heat storage tank ST in FIG.
It is a longitudinal section of R. The heat exchanger 13 in the heat storage tank STR connects a large-diameter heat transfer tube 13a and a small-diameter heat transfer tube 13b in the heat storage tank STR in parallel, and the arrangement thereof is as shown in FIG. A heat transfer tube 13b having a small diameter is arranged at the center of the heat transfer tube 13a having a large diameter (a point located equidistant from the vertex of the equilateral triangle).

Further, with respect to the pipe length per system (path) of the heat transfer tube, the pressure loss of the heat transfer tube 13a having a large diameter and the pressure loss of the heat transfer tube 13b having a small diameter are made equal to each other. In order to perform the branch flow uniformly, the heat transfer tube 13a having a small pressure loss and a large tube diameter is set to be long, and the heat transfer tube 13b having a large pressure loss and a small tube diameter is set to be short.

In the outdoor unit 11, the compressor 2
The four-way valve 3, the outdoor heat exchanger 4, and the expansion valve 5 are sequentially communicated with each other. Are connected in parallel with each other to form a primary refrigeration cycle.

On the other hand, the heat exchanger 13 in the STR in the heat storage tank
And the secondary-side heat exchange section 14b of the refrigerant-to-refrigerant heat exchanger HEX
And the reversible refrigerant transfer pump PM and the indoor heat exchanger 17
Are sequentially communicated to form a secondary refrigeration cycle.

The heat exchanger 13 in the heat storage tank STR is
Three-way valves KV3 and KV installed at the entrance of the heat storage tank STR
By the control of 4, the communication is made with the primary refrigeration cycle or the secondary refrigeration cycle.

Next, the operation of this embodiment will be described. Table 1 shows the open / closed states of the four-way valve 3, the expansion valve 5, the three-way valves KV1, KV3, and KV4, and the operation states (evaporators or condensers) of the heat exchangers in each case in this embodiment. This will be described below with reference to (Table 1).

[0028]

[Table 1]

The mode of the four-way valve 3 is defined as a cooling mode in which 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. A case where the discharge side of the compressor 2 communicates with the heat storage tank STR, and the case where the suction side of the compressor 2 communicates with the outdoor heat exchanger 4 are defined as a heating mode.

For the three-way valve KV1, the first mode is set so that the heat storage tank STR and the expansion valve 5 are connected in the primary side refrigeration cycle, and the refrigerant-to-refrigerant heat exchanger HEX and the expansion valve 5 are connected. The setting is defined as a second mode.

The three-way valves KV3 and KV4 are set so that the heat exchanger 13 in the heat storage tank STR is connected to the primary refrigeration cycle in the primary mode, and the heat exchanger 13 in the heat storage tank STR is set to two. The mode communicating with the secondary refrigeration cycle is defined as the secondary mode.

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

The heat exchanger 13 in the STR in the heat storage tank
Switches the three-way valve KV3 and the three-way valve KV4 to communicate with the primary-side refrigeration cycle. The operation of the primary refrigeration cycle in this case will be described below.

Night-time ice making operation: the four-way valve 3 is in the cooling mode, the expansion valve 5 is in the predetermined opening degree, the three-way valve KV1 is in the first mode, and the three-way valves KV3 and KV4 are in the primary mode.

At this time, the high-temperature and high-pressure refrigerant sent from the compressor 2 is condensed in the outdoor heat exchanger 4 and decompressed by the expansion valve 5 to be in a liquid or two-phase state, and the heat exchange in the heat storage tank STR is performed. After evaporating in the tube of the vessel 13 and absorbing heat from the water 16,
Return to the compressor 2.

That is, the water 16 in the heat storage tank STR is
Since heat is taken through the heat exchanger tube 13a having a large diameter and the heat exchanger tube 13b having a small diameter of the heat exchanger 13 in the TR,
Ice is generated on the outer surfaces of the heat transfer tubes 13a and 13b.

FIG. 3 shows the state of icing in the heat exchanger 13 in the heat storage tank STR at this time. Since the heat exchangers 13 in the heat storage tank STR are arranged such that the heat transfer tubes 13b having a small diameter are located at the center of the heat transfer tube group 13a having a large diameter arranged in a regular triangular shape, FIG. As described above, compared to the arrangement of heat transfer tubes having the same diameter, the ratio of ice to the heat storage tank volume can be increased, and an efficient ice making operation can be performed.

Night heat storage operation: The four-way valve 3 is in the heating mode, the expansion valve 5 is in the 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
After being condensed in the tube of the heat exchanger 13 in the heat storage tank STR and radiating heat to the water 16 as a heat storage material, the pressure is reduced by the expansion valve 5 to be in a liquid or two-phase state. After returning to the compressor 2 after evaporating and absorbing heat from outside the room.

That is, the water 16 in the heat storage tank STR is heated via the heat transfer tube 13a having a large diameter and the heat transfer tube 13b having a small diameter of the heat exchanger 13 in the heat storage tank STR, and is stored as hot water. .

Next, the daytime operation (secondary refrigeration cycle) will be described. In this case, cold storage (heat storage) is performed in the heat storage tank STR, and the three-way valve K is used in the primary refrigeration cycle.
V1 as the first mode, the refrigerant-to-refrigerant heat exchanger HEX 2
The operation is performed with the secondary heat exchange section 14a acting as an evaporator (condenser).

At the same time, in the secondary side refrigeration cycle, the three-way valves KV3 and KV4 are set to the secondary side mode, and the operation is performed by operating the secondary side heat exchange section 14b of the refrigerant-to-refrigerant heat exchanger HEX.

In this state, the refrigerant in the secondary refrigeration cycle is sent by the refrigerant transport pump PM to the heat exchanger 13 in the heat storage tank STR and the secondary side 14b of the refrigerant-to-refrigerant heat exchanger HEX. The heat is exchanged with water 16 as the heat storage material in the heat storage tank STR and the refrigerant in the primary refrigeration cycle.

During cooling, the refrigerant flows as indicated by the solid arrow a in FIG. 1, and the refrigerant cooled in the heat exchanger 13 in the heat storage tank STR is further cooled by the secondary heat of the refrigerant-to-refrigerant heat exchanger HEX. The refrigerant is sent to the exchange unit 14b and is cooled by heat exchange with the secondary heat exchange unit 14a of the refrigerant-to-refrigerant heat exchanger HEX in the primary refrigeration cycle to become a liquid refrigerant.

Thereafter, the air is sent to the indoor heat exchanger 17, where it exchanges heat with the indoor air to cool the indoor air.
The refrigerant itself becomes a high-temperature gas refrigerant, and repeats the operation of returning to the heat exchanger 13 in the heat storage tank STR.

During the heating, the refrigerant flows as indicated by a dashed arrow b in FIG. 1, and the refrigerant-to-refrigerant heat exchange in the primary-side refrigeration cycle is performed in the secondary-side heat exchange section 14b of the refrigerant-to-refrigerant heat exchanger HEX. The refrigerant heated by the heat exchange with the primary heat exchange unit 14a of the heat exchanger HEX is further sent to the heat exchanger 13 in the heat storage tank STR, and is heated by the heat exchange with the hot water 16 in the heat storage tank STR. It becomes a gas refrigerant.

Thereafter, the air is sent to the indoor heat exchanger 17, where it exchanges heat with the indoor air to heat the indoor air.
The refrigerant repeats itself as a low-temperature liquid refrigerant and returns to the reversible refrigerant transport pump PM.

In this way, it is possible to cope with a large daytime indoor load, and the cooling / heating operation is performed by the indoor unit.

As described above, in the above embodiment, in a regenerative air conditioner comprising a primary side refrigeration cycle and a secondary side refrigeration cycle, the heat exchanger 13 in the heat storage tank STR is provided with two or more types having different pipe diameters. Are connected in parallel, and the heat transfer tubes 13b having a small diameter are arranged at the center of a heat transfer tube group 13a having a large diameter arranged in a regular triangular shape.

Thus, the cooling or heating operation can be performed in the daytime by the cold storage heat using the nighttime electric power, and the power usage can be leveled.

In particular, in the case of the cooling operation, in the night ice making operation, the ratio of ice to the volume of the heat storage tank can be increased as compared with the arrangement of the heat transfer tubes having the same diameter, and the efficiency is improved. The ice making operation can be performed, and the response to the indoor heat load is improved.

[0051]

As described above, according to the present invention, in a regenerative air conditioner including a primary refrigeration cycle and a secondary refrigeration cycle via a heat storage tank, the heat exchanger in the heat storage tank has a pipe diameter. Two or more different types of heat transfer tubes are connected in parallel, and the heat transfer tubes having a small diameter are arranged at the center of a group of heat transfer tubes having a large diameter arranged in an equilateral triangle.

Thus, heating or cooling operation can be performed in the daytime by the cold storage heat using the nighttime electric power, and the power usage can be leveled.

In particular, in the case of the cooling operation, in the night ice making operation, ice accumulates around the heat transfer tubes having different diameters of the heat exchangers in the heat storage tank. The heat transfer tubes with smaller diameters are arranged in the center of the tube, so that the ratio of ice to the volume of the heat storage tank can be increased compared to the arrangement with heat transfer tubes of the same diameter, and the efficiency is improved. Ice making operation can be performed, and the responsiveness to the indoor heat load is enhanced.

[Brief description of the drawings]

FIG. 1 is a refrigeration cycle diagram of a regenerative air conditioner according to one embodiment of the present invention.

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

FIG. 3 is a cross-sectional view showing a state of icing on a heat transfer tube of a heat exchanger in a heat storage tank according to one embodiment of the present invention.

FIG. 4 is a refrigeration cycle 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 to refrigerant heat exchanger 14b Secondary heat exchange part of refrigerant to refrigerant heat exchanger 17 Indoor heat exchanger STR Heat storage tank P1, P2 Heat transfer tube F fin HEX Refrigerant to refrigerant heat exchanger PM Refrigerant transfer pump KV1, KV3, KV4 Three-way valve

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kozo Suzuki 1-3-1 Uchisaiwaicho, Chiyoda-ku, Tokyo Tokyo Electric Power Company (72) Inventor Yoshihide Sugita 1-3-1 Uchisaiwaicho, Chiyoda-ku, Tokyo TEPCO (56) References JP-A-3-91658 (JP, A) JP-A-3-79965 (JP, A) JP-A-5-340632 (JP, A) JP-A-4-187952 (JP, A) A) JP-A-3-221787 (JP, A) JP-A-5-346246 (JP, A) JP-A-5-346248 (JP, A) JP-A-5-346249 (JP, A) −78835 (JP, U) Actually open 1987-185375 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) F24F 5/00 F25B 13/00 F25C 1/00

Claims (1)

(57) [Claims] 1. A compressor, a four-way valve, an outdoor heat exchanger, an expansion valve, and a first switching valve are connected in series, and a primary heat exchange unit and a secondary heat exchange unit are connected. A primary heat exchange section of a refrigerant-to-refrigerant heat exchanger having a heat exchanger and a heat exchanger in a heat storage tank having a second switching valve are arranged in parallel, and a refrigerant flow path is provided by the switching valve. A first-side refrigeration cycle capable of switching, a heat exchanger in the heat storage tank, a third switching valve, a secondary-side heat exchange section of the refrigerant-to-refrigerant heat exchanger, a refrigerant transfer pump,
A secondary refrigeration cycle in which an indoor heat exchanger is connected in a ring shape;
A heat storage type air conditioner in which more than two types of heat transfer tubes are connected in parallel, and a heat transfer tube with a small diameter is arranged in the center of a group of large diameter heat transfer tubes arranged in an equilateral triangle.