JPH09138022A - Multi-chamber cooling and heating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent circulating refrigerant from generating change in composition even when excessive refrigerant is generated in a cycle by a method wherein non-azeotropic mixture refrigerant is employed for refrigerant and the operating result of a suction superheating degree operating means is compared with a predetermined set superheating degree while first and second two-way valves are driven to regulate the opening times thereof based on the deciding result of the comparison. SOLUTION: Non-azeotropci mixture refrigerant is employed for refrigerant and a suction superheating degree is operated based on a suction pressure, detected by a suction pressure sensor 18, and a suction temperature, detected by a suction temperature sensor 19. The result of operation is compared with a predetermined set superheating degree by a suction superheating degree deciding means 24. First and second two-way valves 14, 16 are driven by a two-way valve driving means 25 based on the result of decision of comparison and the opening time of the valves 14, 16 are regulated by a valve opening means 26. According to this method, circulating refrigerant can be prevented from the change of composition even when excessive refrigerant is generated in a cycle.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-room cooling / heating system using a non-azeotropic refrigerant mixture, and to a control for adjusting a refrigerant amount during a heating operation.

[0002]

2. Description of the Related Art The prior art is disclosed in Japanese Patent Application Laid-Open No. 6-1376.
There is a multi-room air conditioner as disclosed in Japanese Patent Application Publication No. 91-91.

[0003] The prior art will be described below with reference to the drawings. In FIG. 5, 1 is a compressor, 2 is a four-way valve, 3 is an accumulator, 4 is an outdoor heat exchanger, 5 is an outdoor expansion valve, and 6 is an outdoor fan.
Is formed.

8a and 8b are indoor heat exchangers, 9a and 9b
Is an indoor expansion valve, 10a and 10b are indoor fans,
These form the indoor units 11a and 11b.

The outdoor unit 7 and the indoor units 11a, 11b
Are connected annularly by a liquid pipe 12 and a gas pipe 13.

[0006] The operation of the multi-room air-conditioning apparatus configured as described above will be described. First, during the cooling operation, the high-temperature and high-pressure gas compressed by the compressor 1 is sent to the outdoor heat exchanger 4 via the four-way valve 2 and radiated to outdoor air by the outdoor fan 6 to condense and liquefy. Through the expansion valve 5, the indoor units 11a,
11b.

The refrigerant is decompressed by the indoor expansion valves 9a and 9b, becomes low-temperature and low-pressure two-phase refrigerant, and is sent to the indoor heat exchangers 8a and 8b. The indoor fans 10a and 10b remove the heat of the indoor air. The heat is absorbed and cooled to evaporate gas, and returns to the compressor 1 via the four-way valve 2 and the accumulator 3.

At this time, the degree of opening of the indoor expansion valves 9a and 9b generally controls the degree of superheat at the outlets of the indoor heat exchangers 8a and 8b, so that the refrigerant in the accumulator 3 is affected by fluctuations in the air conditioning load. Irrespective of this, the state becomes a superheated gas state and the excess refrigerant does not accumulate.

Next, during the heating operation, the high-temperature and high-pressure gas compressed by the compressor 1 is passed through the four-way valve 2 to the indoor heat exchanger 8.
a, 8b, the indoor fans 10a, 10b radiate and heat the indoor air to condense it, and the indoor expansion valves 9a, 9b
The proper circulation amount is controlled by and is sent to the outdoor unit 7.

The refrigerant is decompressed by the outdoor expansion valve 5 and is sent to the outdoor heat exchanger 4 in a low-temperature and low-pressure two-phase state. The outdoor fan 6 absorbs heat of the outdoor air and evaporates. Then, the flow returns to the compressor 1 via the four-way valve 2 and the accumulator 3.

[0011]

However, in the above-described configuration, when a non-azeotropic mixed refrigerant is used as the HCFC22 substitute refrigerant during the heating operation, an operation state in which the indoor air-conditioning load is large (for example, all the indoor units are operated) In the state where there is no stop), the amount of refrigerant not accumulated in the stop
Excess refrigerant accumulates in the accumulator 3 as a liquid, and the low-boiling refrigerant evaporates into gas inside the accumulator 3.

Therefore, the composition ratio of the low boiling point refrigerant in the gas refrigerant sucked into the compressor 1, that is, the circulating refrigerant, becomes higher, and the condensation temperature becomes higher than that in the sealed composition even under the same pressure.

[0013] For this reason, there has been a problem that when the condensing pressure constant control is performed, the heating capacity is reduced.

The present invention solves the above-mentioned problems. In a heating operation using a non-azeotropic mixed refrigerant, even if excess refrigerant is generated in the cycle, the composition of the circulating refrigerant is prevented from changing and the condensation is prevented. It is an object of the present invention to provide a multi-room air-conditioning apparatus capable of ensuring a desired capacity without a decrease in heating capacity even when pressure constant control is performed.

[0015]

In order to achieve this object, a multi-room cooling and heating apparatus of the present invention comprises a bypass circuit formed by connecting a first two-way valve, a receiver tank and a second two-way valve. One of the bypass circuits is connected between the outdoor expansion valve and the plurality of indoor units, and the other one is connected between the suction port of the compressor and the four-way valve to detect the suction pressure and the suction temperature of the compressor. Suction pressure temperature detection means, suction superheat degree calculation means for calculating the superheat degree of the suction refrigerant based on this detection result, suction superheat degree determination means for comparing and comparing the calculation result and a preset superheat degree, A two-way valve drive means for driving the first two-way valve and the second two-way valve, and a valve opening means for adjusting the opening time of the driven first two-way valve or the second two-way valve based on this determination result. It is configured with and.

As a result, in the heating operation in which the non-azeotropic mixed refrigerant is used, the heating capacity does not decrease even if the constant condensing pressure is controlled, and the desired capacity can be secured.

Also, a first two-way valve, a receiver tank, a second
A two-way valve is connected to form a bypass circuit, one of the bypass circuits is connected between the outdoor expansion valve and a plurality of indoor units, and the other one is connected between the suction port of the compressor and the four-way valve. Discharge pressure temperature detecting means for detecting the discharge pressure and the discharge temperature of the compressor, a discharge superheat degree calculating means for calculating the superheat degree of the discharge refrigerant based on the detection result, and the calculation result and a predetermined value. Discharge superheat degree determining means for making a comparison with the set superheat degree, two-way valve driving means for driving the first two-way valve and the second two-way valve based on the result of the determination, and a driven first two-way valve. Alternatively, it is configured to include valve opening means for adjusting the opening time of the second two-way valve.

As a result, in the heating operation using the non-azeotropic mixed refrigerant, the heating capacity does not decrease even if the condensing pressure constant control is performed, the desired capacity can be secured, and the control stability can be improved. .

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is directed to a compressor, a four-way valve, an outdoor heat exchanger, an outdoor expansion valve,
An outdoor unit including a first two-way valve, a receiver tank, and a second two-way valve, and a plurality of indoor units including an indoor heat exchanger and an indoor expansion valve are annularly connected to form a refrigerant circuit. 1. A two-way valve, a receiver tank, and a second two-way valve are connected to form a bypass circuit, one of the bypass circuits is connected between the outdoor expansion valve and a plurality of indoor units, and the other one is a compressor. Suction pressure temperature detecting means for communicating between the suction port and the four-way valve for detecting the suction pressure and suction temperature of the compressor, and the superheat degree of the suction refrigerant is calculated based on the detection result of the suction pressure temperature detecting means. A first two-way valve based on the determination result of the suction superheat degree calculation means, the suction superheat degree determination means for comparing and comparing the calculation result of the suction superheat degree calculation means with a predetermined set superheat degree. And a second two-way valve driving means for driving the second two-way valve, and a two-way valve driving means And a valve opening means for adjusting the opening time of the two-way valve or the second two-way valve. The suction pressure temperature detecting means detects the pressure and temperature of the refrigerant sucked into the compressor, and based on this, suction overheating. Degree calculating means calculates the superheat degree of the refrigerant sucked into the compressor, and based on this result, the suction superheat degree judging means judges whether the suction superheat degree is larger or smaller than a set value.

When the intake superheat degree is small, the first two-way valve is opened by the two-way valve drive means, and the opening time is adjusted by the valve opening means,
It has the function of accumulating excess refrigerant in the receiver tank and adjusting the amount of refrigerant in the cycle.

When the intake superheat is large, the second two-way valve is opened by the two-way valve driving means, the opening time is adjusted by the valve opening means, the refrigerant is taken out from the receiver tank, and the refrigerant in the cycle is cooled. It has the function of adjusting the amount.

According to a second aspect of the present invention, an outdoor unit including a compressor, a four-way valve, an outdoor heat exchanger, an outdoor expansion valve, a first two-way valve, a receiver tank, and a second two-way valve, and an outdoor unit A refrigerant circuit is configured by annularly connecting a plurality of indoor units including an inner heat exchanger and indoor expansion valves, and a bypass circuit is configured by connecting a first two-way valve, a receiver tank, and a second two-way valve. Then, one of the bypass circuits is connected between the outdoor expansion valve and multiple indoor units, and the other one is connected between the suction port of the compressor and the four-way valve, and the discharge pressure and discharge temperature of the compressor are connected. Discharge pressure temperature detecting means for detecting, and discharge superheat degree calculating means for calculating the superheat degree of the discharge refrigerant based on the detection result of the discharge pressure temperature detecting means,
Discharge superheat degree determination means for comparing and comparing the calculation result of the discharge superheat degree calculation means with a predetermined set superheat degree, and a first two-way valve and a second two-way valve based on the determination result of the discharge superheat degree determination means. And a valve opening means for adjusting the opening time of the first two-way valve or the second two-way valve driven by the two-way valve driving means. The pressure and temperature of the compressor discharge refrigerant is detected by the means, the superheat degree of the compressor discharge refrigerant is calculated by the discharge superheat degree calculation means based on this, and the discharge superheat degree is calculated by the discharge superheat degree judging means based on this result. Judge whether it is larger or smaller than the set value.

When the discharge superheat degree is small, the first two-way valve is opened by the two-way valve driving means, and the opening time is adjusted by the valve opening means,
It has the function of accumulating excess refrigerant in the receiver tank and adjusting the amount of refrigerant in the cycle.

When the discharge superheat degree is large, the second two-way valve is opened by the two-way valve driving means, the opening time is adjusted by the valve opening means, the refrigerant is taken out from the receiver tank, and the refrigerant in the cycle is discharged. It has the function of adjusting the amount.

Further, by setting the discharge superheat degree as a control item, the control stability is improved.

Hereinafter, an embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. (Embodiment 1) FIG. 1 is a refrigerant cycle diagram of a multi-room cooling / heating device according to a first embodiment. FIG. 2 is an operation flowchart during a heating operation according to the embodiment.

The same components as those in the prior art are designated by the same reference numerals, and detailed description thereof will be omitted. In FIG. 1, 14
Denotes a first two-way valve, which uses an electromagnetic valve. Reference numeral 15 denotes a receiver tank. Reference numeral 16 denotes a second two-way valve, which uses an electromagnetic valve. Reference numeral 17 denotes a bypass circuit, which connects the first two-way valve 14, the receiver tank 15, and the second two-way valve 16 in series, and communicates the vicinity of the outdoor expansion valve 5 of the liquid pipe 12 with the suction pipe of the compressor 1. doing.

Reference numeral 18 is a suction pressure sensor, and the compressor 1
Attached to the suction pipe. Reference numeral 19 denotes a suction temperature sensor, which is attached to a suction pipe of the compressor 1. 2
Reference numeral 0 is a microcomputer, and the opening time of the first two-way valve 14 or the second two-way valve 16 is set. 21 is an outdoor unit.

Reference numeral 22 is a suction pressure temperature detecting means, in which the suction pressure sensor 18 detects the suction pressure and the suction temperature sensor 19 detects the suction temperature.

Reference numeral 23 is a suction superheat degree calculating means, which calculates the suction superheat degree based on the detected suction pressure and suction temperature. 2
Reference numeral 4 denotes an intake superheat degree determining means, which compares and determines whether the intake superheat degree is larger or smaller than a predetermined set superheat degree.

Reference numeral 25 denotes a two-way valve driving means, which opens and closes the first two-way valve 14 or the second two-way valve 16 based on the judgment of the suction superheat judging means 24. 26 is a valve opening means,
First two-way valve 14 or second opened by the two-way valve drive means 25
The two-way valve 16 is left open for the time set in the microcomputer 20.

Reference numeral 27 denotes a control device, which comprises an intake pressure temperature detecting means 22, an intake superheat degree calculating means 23, an intake superheat degree determining means 24, a two-way valve driving means 25, and a valve opening means 26.

The operation of the multi-room cooling and heating apparatus having the above-described structure when the non-azeotropic mixed refrigerant is used will be described with reference to FIG.

In FIG. 2, Step 1 is the suction pressure temperature detecting means 22, the suction pressure Ps is detected by the suction pressure sensor 18, the suction temperature Ts is detected by the suction temperature sensor 19, and the process proceeds to Step 2.

Step 2 is the intake superheat degree calculating means 23, which calculates the intake superheat degree SHs from the following equation based on Ps and Ts, and shifts to Step 3.

SHs = f (Ps, Ts) Step 3 is an intake superheat degree judging means 24, and compares SHs to be larger or smaller than a predetermined set superheat degree.

In the present invention, the allowable range of the set superheat degree is defined as 5K <the set superheat degree ≦ 10K. When SHs is SHs ≦ 5K, the SHs is small and excess refrigerant is generated in the cycle. If it is determined that there is, the process proceeds to Step 4.

Step 4 is a two-way valve drive means 25,
The first two-way valve 14 is opened to allow the refrigerant to flow into the receiver tank 15, and the process proceeds to Step 5.

Step 5 is the valve opening means 26, and in the present invention, the first two-way valve 14 is kept open for a preset time of the microcomputer 20, for example, and the process proceeds to Step 6.

Step 6 is the two-way valve driving means 25, which closes the first two-way valve 14 and returns to Step 1.

If SHs ≦ 5K is not satisfied in Step 3, the process proceeds to Step 7.

Step 7 is the intake superheat degree determining means 24. When SHs> 10K, it is determined that SHs is larger than the set superheat degree and the amount of refrigerant in the cycle is insufficient, and the process proceeds to Step 8.

Step 8 is a two-way valve drive means 25,
The second two-way valve 16 is opened to allow the refrigerant in the receiver tank 15 to flow out, and the process proceeds to Step 9.

Step 9 is the valve opening means 26, and in the present invention, the second two-way valve 16 is left open for a preset time of the microcomputer 20, and the process proceeds to Step 10.

Step 10 is the two-way valve driving means 25, which closes the second two-way valve 16 and returns to Step 1.

In Step 7, if SHs> 10K is not satisfied, it is determined that SHs is within the allowable range of the set superheat degree and the amount of refrigerant in the cycle is appropriate, and St
Return to ep1.

According to the first embodiment, in the heating operation when the non-azeotropic mixed refrigerant is used, the excess refrigerant generated in the cycle is stored in the receiver tank 15 to adjust the refrigerant amount.

Since the receiver tank 15 is closed by the first two-way valve 14 and the second two-way valve 16, the composition change of the circulating refrigerant can be prevented, and the heating capacity does not decrease even if the condensing pressure constant control is performed. The desired ability can be secured.

(Second Embodiment) FIG. 3 is a refrigerant cycle diagram of a multi-room cooling and heating apparatus according to the second embodiment. FIG.
4 is an operation flowchart during a heating operation in the embodiment.

The same components as those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

In FIG. 3, a discharge pressure sensor 28 is attached to the discharge pipe of the compressor 1. A discharge temperature sensor 29 is attached to the discharge pipe of the compressor 1. 30 is an outdoor unit.

Reference numeral 31 is a discharge pressure temperature detecting means, in which the discharge pressure sensor 28 detects the discharge pressure and the discharge temperature sensor 29 detects the discharge temperature.

Reference numeral 32 is a discharge superheat degree calculating means, which calculates the discharge superheat degree based on the detected discharge pressure and discharge temperature. 3
Reference numeral 3 denotes a discharge superheat degree determination means, which compares and determines whether the discharge superheat degree is larger or smaller than a preset set superheat degree.

Reference numeral 34 denotes a control device, which comprises a discharge pressure temperature detecting means 31, a discharge superheat degree calculating means 32, a discharge superheat degree judging means 33, a two-way valve driving means 25, and a valve opening means 26.

The operation of the multi-room cooling and heating apparatus having the above-mentioned structure when the non-azeotropic mixed refrigerant is used will be described with reference to FIG.

In FIG. 4, Step 1 is the discharge pressure temperature detecting means 31, the discharge pressure Pd is detected by the discharge pressure sensor 28, the discharge temperature Td is detected by the discharge temperature sensor 29, and the process proceeds to Step 2.

Step 2 is the discharge superheat degree calculating means 32, which calculates the discharge superheat degree SHd from the following equation based on Pd and Td, and shifts to Step 3.

SHd = f (Pd, Td) Step 3 is the discharge superheat degree judging means 33, which compares whether SHd is larger or smaller than a predetermined set superheat degree.

In the present invention, the allowable range of the set superheat degree is defined as 20K <the set superheat degree ≦ 40K. When SHd is SHd ≦ 20K, the SHd is small and excess refrigerant is generated in the cycle. If it is determined that there is, the process proceeds to Step 4.

Step 4 is a two-way valve drive means 25,
The first two-way valve 14 is opened to allow the refrigerant to flow into the receiver tank 15, and the process proceeds to Step 5.

Step 5 is the valve opening means 26, and in the present invention, the first two-way valve 14 is kept open for a preset time for the microcomputer 20, for example, and the process proceeds to Step 6.

Step 6 is the two-way valve driving means 25, which closes the first two-way valve 14 and returns to Step 1.

If SHd ≦ 20K in Step 3, the process proceeds to Step 7.

Step 7 is the discharge superheat degree judging means 33. When SHd> 40K, it is judged that SHd is larger than the set superheat degree, and the amount of refrigerant in the cycle is insufficient, and the process proceeds to Step 8.

Step 8 is a two-way valve drive means 25,
The second two-way valve 16 is opened to allow the refrigerant in the receiver tank 15 to flow out, and the process proceeds to Step 9.

Step 9 is the valve opening means 26, and in the present invention, the second two-way valve 16 is left open for a preset time for the microcomputer 20, and the process proceeds to Step 10.

Step 10 is the two-way valve driving means 25, which closes the second two-way valve 16 and returns to Step 1.

In Step 7, if SHd> 40K is not satisfied, it is judged that SHd is within the allowable range of the set superheat degree and the amount of refrigerant in the cycle is appropriate, and St
Return to ep1.

According to the second embodiment, in the heating operation when the non-azeotropic mixed refrigerant is used, the excess refrigerant generated in the cycle is stored in the receiver tank 15 to adjust the refrigerant amount.

Since the receiver tank 15 is closed by the first two-way valve 14 and the second two-way valve 16, the composition change of the circulating refrigerant can be prevented and the heating capacity does not decrease even if the condensing pressure constant control is performed. The desired ability can be secured.

Further, since the discharge superheat degree is used as a control item, the allowable range of the set superheat degree can be increased and the control stability can be improved.

[0072]

As described above, according to the present invention, in the heating operation using a non-azeotropic refrigerant mixture, the heating capacity does not decrease even if the condensing pressure constant control is performed, and the desired capacity can be secured. The advantageous effect described above can be obtained.

By setting the discharge superheat degree as a control item, the advantageous effect that the control stability is improved can be obtained.

[Brief description of the drawings]

FIG. 1 is a refrigerant cycle diagram of a multi-room cooling / heating device according to a first embodiment of the present invention.

FIG. 2 is an operation flowchart during a heating operation in the embodiment.

FIG. 3 is a refrigerant cycle diagram of a multi-room cooling / heating device according to a second embodiment of the present invention.

FIG. 4 is an operation flowchart during a heating operation in the embodiment.

FIG. 5 is a refrigerant cycle diagram of a conventional multi-room cooling / heating device.

[Explanation of symbols]

 1 compressor 2 4-way valve 4 outdoor heat exchanger 5 outdoor expansion valve 8a, 8b indoor heat exchanger 9a, 9b indoor expansion valve 11a, 11b indoor unit 14 first two-way valve 15 receiver tank 16 second second One-way valve 17 Bypass circuit 21 Outdoor unit 22 Intake pressure temperature detecting means 23 Intake superheat degree calculating means 24 Intake superheat degree determining means 25 Two-way valve driving means 26 Valve opening means 30 Outdoor unit 31 Discharge pressure temperature detecting means 32 Discharge superheat degree calculation Means 33 Discharge superheat degree judging means

Claims (2)

[Claims] 1. An outdoor unit comprising a compressor, a four-way valve, an outdoor heat exchanger, an outdoor expansion valve, a first two-way valve, a receiver tank, and a second two-way valve; an indoor heat exchanger; A refrigerant circuit is configured by annularly connecting a plurality of indoor units including an expansion valve,
A bypass circuit is formed by connecting the first two-way valve, the receiver tank, and the second two-way valve, and one of the bypass circuits is connected between the outdoor expansion valve and the plurality of indoor units. , The other one is connected between the suction port of the compressor and the four-way valve, suction pressure temperature detection means for detecting the suction pressure and suction temperature of the compressor, and the detection result of the suction pressure temperature detection means Suction superheat degree calculating means for calculating the superheat degree of the suction refrigerant based on the above, suction superheat degree judging means for comparing the calculation result of the suction superheat degree calculating means with a predetermined set superheat degree, and the suction superheat degree Two-way valve drive means for driving the first two-way valve and the second two-way valve based on the determination result of the determination means, and the first two-way valve or the second one-way valve driven by the two-way valve drive means 2 a valve opening means for adjusting the opening time of the two-way valve, Multi-chamber cooling and heating apparatus using a boiling mixed refrigerant. 2. An outdoor unit comprising a compressor, a four-way valve, an outdoor heat exchanger, an outdoor expansion valve, a first two-way valve, a receiver tank, and a second two-way valve; an indoor heat exchanger; A refrigerant circuit is configured by annularly connecting a plurality of indoor units including an expansion valve,
A bypass circuit is formed by connecting the first two-way valve, the receiver tank, and the second two-way valve, and one of the bypass circuits is connected between the outdoor expansion valve and the plurality of indoor units. , The other one is connected between the suction port of the compressor and the four-way valve, discharge pressure temperature detection means for detecting the discharge pressure and discharge temperature of the compressor, and the detection result of the discharge pressure temperature detection means Discharge superheat degree calculating means for calculating the superheat degree of the discharge refrigerant based on the above, discharge superheat degree determining means for comparing and comparing the calculation result of the discharge superheat degree calculating means with a preset set superheat degree, and the discharge superheat degree Two-way valve drive means for driving the first two-way valve and the second two-way valve based on the determination result of the determination means, and the first two-way valve or the second one-way valve driven by the two-way valve drive means 2 a valve opening means for adjusting the opening time of the two-way valve, Multi-chamber cooling and heating apparatus using a boiling mixed refrigerant.