JP2000161721A - Air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To quickly cool by utilizing a cold thermal storage power even when a compressor is stopped, by giving a cold power to a brine at a cold thermal storage material through a cold thermal storage material to brine heat exchanger when a cooling operation is advanced so that an allowance is incorporated in the supplied cold power, and storing it in a cold thermal storage tank. SOLUTION: A refrigerant compressed by a compressor 4 is radiated by an outdoor heat exchanger 5 to a refrigerant of low temperature pressure by an expansion valve 6, then fed to a refrigerant to brine heat exchanger 7, and hence a brine is cooled by heat exchanging. The cooled brine is circulated in a brine cycle 2 by a pump 9, and sent to an evaporator 10 to cool indoor air. In this case, when a cooling operation is advanced so that an allowance is incorporated in a supplied cold power, a pump 11 is operated, a cold thermal storage material of a cold storage cycle 3 is thermally exchanged with the brine by a cold thermal storage material to brine heat exchanger 8 to store cold power in a cold thermal storage tank 12. The cold thermal stored cold power is used for indoor cooling after the compressor is stopped.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner used for air-conditioning the interior of a vehicle or the like, and more specifically, to a brine type heat exchanger in which refrigerant in a refrigeration cycle exchanges heat with room air through brine. It relates to an air conditioner.

[0002]

2. Description of the Related Art In order to avoid direct introduction of a flammable refrigerant such as a hydrocarbon-based refrigerant into a room, heat is exchanged between the flammable refrigerant and the brine outside the room. A brine type air conditioner that is replaced is disclosed in, for example, Japanese Patent Application Laid-Open No. 10-71848.

The air conditioner disclosed in the publication has a configuration as shown in FIG. 4, and includes a refrigeration cycle A for cooling brine using a hydrocarbon-based refrigerant, and cooling by the refrigeration cycle A. A brine cycle D for supplying brine to heat exchangers B and C connected in parallel to pipes provided in the front air conditioning unit and the rear air conditioning unit, and on a cycle path of the rear air conditioning unit of the brine cycle D. In addition, a cold storage tank E for storing the cooled brine in a low temperature state is provided, and the cooling responsiveness is enhanced by using the low temperature brine in the cold storage tank at the time of starting.

[0004]

However, the above-mentioned air conditioner has a configuration in which a regenerative tank is provided on a brine cycle and the cooling power is accumulated by the brine itself. Cold storage cannot be performed, and there is a problem in the cold storage effect. In addition, since the cold storage tank E is not provided on the circulation path of the frequently used front air conditioning unit, but is provided on the circulation path of the rear air conditioning unit connected in parallel with this, the cold storage tank E is stored in the cold storage tank E. The brine is the heat exchanger B of the front air conditioning unit.
To the heat exchanger B after passing through the heat exchanger F for exchanging heat between the refrigerant of the refrigeration cycle and the brine. That is, the brine warmed by the heat exchanger B is recirculated together with the brine supplied from the cold storage tank E, and there is a concern that the capacity may be insufficient for a request for rapid cooling.

[0005] Therefore, the present invention provides an air conditioner having a cycle configuration that can achieve rapid cooling in a brine type cycle by making full use of the stored cold power and has a high cold storage effect. The challenge is to do.

[0006]

To achieve the above object, an air conditioner according to the present invention exchanges heat between a compressor having means for adjusting a discharge flow rate and refrigerant compressed by the compressor with outside air. An outdoor heat exchanger, a decompression unit for decompressing the refrigerant, and a first unit for exchanging the refrigerant decompressed by the decompression unit with brine.
A refrigeration cycle having a heat exchange section, an indoor heat exchanger for exchanging heat between the brine and indoor air, and a first pump mechanism for circulating the brine to the indoor heat exchanger. A cycle, a regenerative storage tank, a regenerative cycle including a second heat exchange unit that allows the regenerative material stored in the regenerative tank to exchange heat with the brine, and a second pump mechanism that circulates the regenerative material. (Claim 1).

Accordingly, the refrigerant compressed by the compressor by the operation of the refrigeration cycle is radiated by the outdoor heat exchanger, converted into a low-temperature low-pressure refrigerant by the pressure reducing means, and sent to the first heat exchange section. Can be Then, the first heat exchange section exchanges heat with the brine, and cools the brine. The cooled brine is sent to the indoor heat exchanger by circulating a brine cycle by driving the first pump mechanism, and exchanges heat with the indoor air in the indoor heat exchanger to cool the indoor air. .

In the initial stage of cooling, there is often no room for the cooling power to be supplied with respect to the required cooling power due to the large cooling load. Come out. Therefore, in such a case, the second
By operating the pump mechanism, the cold storage material of the cold storage cycle and the brine actively exchange heat, and the cooling power can be stored in the cold storage tank.

The cooling power stored in the cold storage tank is:
When it is desired to maintain indoor cooling even after the compressor is stopped, or when rapid cooling is required, the second pump mechanism is operated to supply the air to the brine.

[0010] The first heat exchange section and the second heat exchange section described above may be combined to form one heat exchanger (claim 2). As such a thing, for example, a heat exchanger having a multilayer structure in which a tube element for flowing brine is directly in contact with a tube element for flowing refrigerant and a tube element for flowing cold storage material can be considered.

[0011]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of the present invention. FIG. 1 shows a brine type air conditioner mounted on a vehicle. The air conditioner includes a refrigeration cycle 1 for circulating a refrigerant, a brine cycle 2 for circulating brine, and a regenerative cycle for circulating a cold storage material. 3 are provided.

The refrigeration cycle 1 includes a variable capacity compressor 4 having a variable capacity mechanism for adjusting the discharge flow rate, an outdoor heat exchanger 5 for condensing and liquefying the refrigerant discharged from the variable capacity compressor 4, and an outdoor heat exchanger 5. An expansion valve 6 for decompressing the refrigerant liquefied by the exchanger 5; and a refrigerant-brine heat exchange unit (first heat exchange unit) for exchanging heat between the refrigerant decompressed by the expansion valve 6 and brine in a brine cycle described below. And 7) are sequentially connected by piping. This refrigeration cycle 1 is disposed outside the vehicle compartment, and a hydrocarbon-based flammable refrigerant such as butane or propane is used as a refrigerant.

The brine cycle 2 includes a first pump 9 for circulating the brine heat-exchanged by the refrigerant-brine heat exchange unit 7 and a regenerator-brine heat exchange unit 8 described later; It is configured by connecting the evaporator 10 to be replaced with a pipe. As the brine, an aqueous solution (organic brine) such as propylene glycol or ethylene glycol, or simply water may be used.

The cool storage cycle 3 is a cool storage material-brine heat exchange section (second heat exchange section) 8 for exchanging heat between the cool storage material enclosed in this cycle and the brine of the brine cycle.
, A second pump 11 for circulating the cold storage material, and a cold storage tank 12 for storing the cooling power of the cold storage material. Here, as the regenerator material, a known material composed of water + inorganic salt (such as Na), water + organic compound (such as glycol or alcohol), or water + inorganic salt + organic compound is used, and cooled by brine. Changes from liquid phase to solid phase (coagulation)
Then, sufficient cooling power is accumulated.

The above-described refrigerant-brine heat exchanging section 7 and the regenerator-brine heat exchanging section 8 may be formed separately or integrally. Even if it is constituted by a double tube for exchanging heat between the brine and the refrigerant or the regenerator material, or as a structure in which the piping of the other cycle is passed through the tank for storing the fluid of one cycle, the common fin or the like may be used as a unit. Even if it is configured such that brine is passed through one of the combined side-by-side heat exchangers and the refrigerant or the cold storage material is passed through the other, even if both heat exchange portions are formed in one heat exchanger, these are combined and configured. May be.

In this configuration example, the refrigerant-brine heat exchange unit 7 and the cold storage material-brine heat exchange unit 8
FIG. 2 shows a configuration integrally formed with one heat exchanger (brine temperature control heat exchanger 20). The heat exchanger 20 for brine temperature control will be described below with reference to FIG.

In the heat exchanger 20 for controlling the temperature of the brine, a tube element 21 for flowing the brine is combined with a tube element 22 for flowing the refrigerant and a tube element 23 for flowing the cold storage material.
Each of the tube elements 21 to 23 is laminated in multiple layers in the order of 21-23-21-22.
Are formed by joining two molding plates face-to-face, and a pair of greatly bulging tank portions 24a provided on one end side.
24b, 24c and passage portion 25 formed subsequently thereto
a, 25b, and 25c, and the passages extend from the partition of the paired tank to the vicinity of the other end.
B and 26c are formed to form a U-shape, and fluid flows from one tank portion to the other tank portion via the passage portion.

The tube element 22 through which the refrigerant flows and the tube element 23 through which the cold storage material flows have a bulging amount of the tank portion that is twice that of the tube element 21 through which the brine flows. Are the passage portions 25a, 25b, 25 without using fins.
The refrigerant-brine heat exchanging part 7 is brought into contact with the passage part 25a through which the brine flows and the passage part 25b through which the refrigerant flows, so that the passage part 25a through which the brine flows and the cold storage material are stacked. The cold storage material-brine heat exchange section 12 is formed by contact with the flowing passage section 25c.

The tank portions of the tube elements through which the same fluid flows are provided so as to protrude from the heat exchange portion in the same direction and are connected to each other, so that the tank portions of the tube elements through which different fluids flow do not interfere with each other. , Are provided in different directions with respect to the heat exchange section. In this configuration example, the tube element 2 through which the brine flows
The first tank portion 24a and the tank portion 24b of the tube element 22 through which the refrigerant flows are provided on the side opposite to the heat exchange portion, and the tank portion 24c of the tube element 23 through which the cold storage material flows is connected to the other tube elements 21. , 22
Are provided at right angles to the tank portions 24a and 24b.

The tube elements joined in the tank section are communicated with each other through a through hole formed in the tank section, and an inlet and an outlet are provided in different tank sections.
The fluid that has flowed in from the inflow port is passed in parallel or in series through the passage portions of the connected tube elements, and flows out of the outflow port.

Accordingly, the temperature of the brine is controlled by adjusting the flow rate of the refrigerant or the flow rate of the cold storage material of the tube elements 22 and 23 abutting on both sides of the tube element 21 through which the brine flows by the compressor 4 or the second pump 11. You.

Incidentally, the above-described evaporator 10
The air introduced into the air-conditioning passage is arranged by the rotation of the blower 33 passing through the air-conditioning passage 32 provided in the vehicle interior 31 together with the heater core 30. The evaporator 10 and the heater core 30 are juxtaposed and juxtaposed so as to be adjacent to each other in the ventilation direction.
0 is provided so as to cover the entire cross section of the passage.
0 is provided so as to close only a part of the passage cross section.

In an actual air conditioning unit, the heater core is configured to circulate hot water heated by an engine or an electric heater (not shown) while adjusting the flow rate. , An intake device is provided, the inside air or the outside air sucked by the blower 33 is temperature-controlled by the evaporator 10 and the heater core 30, and the outlets (defrost outlets, vent outlets, foot outlets) provided at the most downstream side. The vehicle is supplied to the vehicle interior according to the blowout mode selected from.

Reference numeral 35 denotes a group of sensors for detecting the state of the environment inside and outside the vehicle interior. Reference numeral 36 denotes a setter for setting the air-conditioning state of the vehicle interior. To be entered. This control unit 37
Are a central processing unit (CPU), a read only memory (ROM), and a random access memory (RA
M), an input / output port (I / O), etc., and a drive circuit for controlling a compressor, a pump, a flow control valve, etc., and a sensor group and setting according to a predetermined program given to a ROM. Process the signal from the vessel,
The capacity control of the compressor 4 and the drive control of the pumps 9 and 11 are performed.

In the above configuration, the operation during the cooling operation will be described below on the assumption that the supply of hot water to the heater core 30 is stopped. First, if there is a request for the cooling operation, the compressor 4 is operated to operate the refrigeration cycle 1, and further, the first pump 9 is operated to circulate the brine of the brine cycle 3.

Then, in the refrigeration cycle 1, the refrigerant compressed by the compressor 4 is condensed and liquefied by the outdoor heat exchanger 5, and is decompressed by the expansion valve 6 to a low temperature and low pressure. Refrigerant-brine heat exchange unit 7
It is led to. The refrigerant guided to the refrigerant-brine heat exchange unit 7 exchanges heat with the brine of the brine cycle 2 to cool it, and the cooled brine is guided to the evaporator 10 and communicates with the air in the air conditioning passage 32. Heat exchange.

Therefore, the air introduced into the air conditioning passage 32 by the blower 33 is cooled by the evaporator 10, and a part of the air passes through the heater core 30, but is supplied to the passenger compartment 31 without being heated here.

Immediately after the cooling operation, since the cooling load is large, the discharge capacity of the compressor 4 is large, and the cooling power supplied by the refrigeration cycle is hardly larger than the required cooling power. However, when the cooling operation is continued and the room is gradually cooled, the cooling load is gradually reduced, so that the cooling power supplied by the refrigeration cycle 1 has a surplus.

Therefore, at the time when such surplus power is generated, the discharge capacity of the compressor is maintained at a predetermined value or more, the second pump 11 is operated to operate the cold storage cycle 3, and the cold storage material and the brine are actively separated. The heat is exchanged, and the cooling power is accumulated in the cold storage tank 12.

In the above-described refrigeration cycle, since a variable displacement compressor is used, the discharge capacity of the compressor starts to vary from the maximum displacement at the point in time when the cooling power supplied by the refrigeration cycle 1 starts to have a surplus. The point in time at which the compressor starts to change the capacity can be determined based on a change in the current, for example, when controlling the current of the variable capacity mechanism.

Next, in order to utilize the cooling power accumulated in the cold storage tank 12, the second pump 11 is operated to circulate the cold storage material in the cold storage cycle. Then, the cooling power of the cold storage material is supplied to the brine in the cold storage-brine heat exchange unit 8, and the cooled brine is guided to the evaporator 10 by the operation of the brine cycle 2 to exchange heat with the air in the air conditioning passage 32. it can.

For example, when there is a request for rapid cooling at the beginning of cooling, the refrigerating cycle 1 is operated with the discharge capacity of the compressor 4 maximized, and at the same time, the first and second pumps 9 and 11 are operated. Then, the brine can be cooled by the cooling power accumulated in the cold storage tank 12 in addition to the cooling power of the refrigeration cycle 1, and the cooling power supplied to the brine can be increased to realize rapid cooling of the indoor air. it can.

In an air conditioner for stopping the refrigeration cycle 1 in order to reduce the load of power in the idling state, the second pump 11 is operated while the refrigeration cycle 1 is stopped to operate the refrigerating cycle 3. If you run
Indoor cooling can be ensured by the cooling power accumulated in the cold storage tank 12. In other words, if the operation and non-operation of the cold storage cycle 3 are controlled and the cooling power accumulated in the cold storage tank 12 is efficiently used, the refrigeration cycle 1 does not need to be constantly operated, and energy can be saved. It becomes possible.

FIG. 3 shows an example of a flowchart for realizing the various controls described above, and the control during the cooling operation will be described below based on the flowchart. When the cooling operation is started, the control unit 37 determines whether or not the cooling is in the initial stage in Step 50 and determines whether or not there is a request for rapid cooling in Step 54. Here, the presence or absence of the request for rapid cooling is determined by whether or not the deviation of the actual room temperature from the target temperature is equal to or more than a predetermined value.

If there is a request for rapid cooling at the beginning of cooling, the compressor is turned on in steps 52 and 56.
N, the first and second pumps are turned on, the refrigeration cycle 1, the brine cycle 2, and the cold storage cycle 3 are operated, and the brine is rapidly cooled by the cooling power supplied from the refrigeration cycle 1 and the cold storage cycle 3. Of course, as a prerequisite for performing this process, it is necessary that the cooling power is sufficiently accumulated in the cold storage tank 12, and the presence or absence of the accumulation of the cooling power is determined by a process not shown in this flow. Also,
When a large cooling power is required, a compressor or secondary
Of the pump may be increased to increase the cooling power supplied to the brine.

If there is no request for rapid cooling at the beginning of cooling, in step 52, the compressor is turned on.
N, the first pump is turned on, the refrigeration cycle 1 and the brine cycle 2 are operated, and the normal cooling operation in which the regenerative cycle 3 is not operated is performed.

If the cooling operation is not in the initial stage, the normal cooling operation is performed in principle. However, if there is a request to stop the refrigeration cycle 1 at the time of idling operation due to a request for energy saving, at step 58, whether the operation is the idling operation or not is determined. Is determined, and if idling, the compressor 4 is turned off,
The first and second pumps 9 and 11 are operated, and the cooling in the vehicle compartment is continued only by the cooling power accumulated in the cold storage tank 12 (step 60).

If it is not during the idling operation, step 62
, The compressor is turned on, the first pump is turned on, and the refrigeration cycle 1 and the brine cycle 2 are operated. In this state, in step 64, it is determined whether or not the discharge capacity of the compressor 4 is variable without being fixed to the maximum discharge capacity, and if the compressor 4 continues to operate at the maximum discharge capacity without changing the capacity, In this case, the second cooling load can be regarded as having a large cooling load.
The normal cooling operation is maintained without operating the pump 11 of FIG.
In addition, when the reserve capacity of the cooling power supplied from the refrigeration cycle 1 appears and the discharge capacity of the compressor starts to vary,
The second pump 11 is operated to activate the cool storage cycle 3, and the compressor 4 is operated at a predetermined capacity or more to store excess cooling power in the cool storage tank 12 (step 66).

That is, by the above-described series of processes, extra cooling power is given to the cold storage material within a range that does not interfere with the cooling control in the vehicle compartment, and is accumulated in the cold storage tank 12, and the accumulated cooling power is described above. In steps 56 and 60, it can be used.

In the above example, the air conditioner mounted on the vehicle has been described. However, the air conditioner may be used as an air conditioner for a house or a factory. Although the variable displacement compressor is used as the compressor, the discharge flow rate may be adjusted by controlling ON / OFF of the fixed displacement compressor.

[0041]

As described above, according to the present invention,
The first heat exchange section enables heat exchange between the brine and the refrigerant in the refrigeration cycle, and the second heat exchange section enables heat exchange between the brine and the cold storage material in the cold storage cycle. If the cooling power supplied from the refrigeration cycle has more reserve capacity, it is possible to accumulate the cooling power in the cold storage tank and adjust the brine temperature as needed using the cold power stored in this cold storage tank. For example, it is possible to cope with a case where there is a request for rapid cooling or a case where there is a request for maintaining indoor cooling when the refrigeration cycle is stopped.

According to the conventional configuration, the cold storage tank is formed on the brine cycle and the cold is stored by the brine itself. Therefore, the cooling power stored in the cold storage tank is limited. It was difficult to cool rapidly using In contrast, according to the present invention,
Since the regenerative cycle having the regenerative storage tank and the brine cycle are formed independently, the regenerative cycle can be independently designed to circulate the regenerative material excellent in the regenerative effect to enhance the regenerative effect. The brine can also be cooled rapidly by increasing the amount of circulation of the regenerative material in the cycle.

When the first heat exchange section and the second heat exchange section are combined to form one heat exchanger, the brine and the refrigerant, and the brine and the regenerator material are provided by one heat exchanger. Heat exchange, the cold storage in the cold storage tank and the temperature of the brine can be controlled accurately, and the mounting space is reduced compared to the case where each heat exchange unit is composed of separate heat exchangers, piping The layout can be reduced, and the layout of piping and the like can be simplified.

[Brief description of the drawings]

FIG. 1 is a diagram showing an overall configuration of an air conditioner according to the present invention.

FIG. 2 is a diagram showing a heat exchanger for brine temperature control used in the air conditioner of FIG. 1; FIG. 2A is a perspective view of the assembled heat exchanger; FIG. b) is an exploded perspective view showing a tube element constituting the heat exchanger.

FIG. 3 is a flowchart illustrating an example of cooling operation control by the air-conditioning apparatus illustrated in FIG. 1;

FIG. 4 is a diagram showing a conventional configuration.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Refrigeration cycle 2 Brine cycle 3 Cold storage cycle 4 Compressor 5 Outdoor heat exchanger 6 Expansion valve 7 Refrigerant-brine heat exchange part 8 Cold storage material-brine heat exchange part 9 First pump 10 Evaporator 11 Second pump 12 Cold storage tank 20 Brine temperature control heat exchanger

Claims (2)

[Claims] 1. A compressor having a means for adjusting a discharge flow rate, an outdoor heat exchanger for exchanging heat of a refrigerant compressed by the compressor with outside air, a decompression means for decompressing the refrigerant, and a decompression means for decompression by the decompression means. A refrigeration cycle having a first heat exchange unit that allows the extracted refrigerant to exchange heat with brine, an indoor heat exchanger that exchanges heat between the brine and indoor air, and an indoor heat exchange that exchanges the brine with the indoor heat. A brine cycle having a first pump mechanism for circulating the cold storage tank, a regenerative storage tank, a second heat exchanging unit for allowing the regenerative material stored in the regenerative tank to exchange heat with the brine, An air conditioner comprising: a regenerative cycle having a second pump mechanism for circulating. 2. The air conditioner according to claim 1, wherein the first heat exchange section and the second heat exchange section are combined to form one heat exchanger. apparatus.