JPH0835725A - Refrigerating air conditioner using non-azeotrope refrigerant - Google Patents

Abstract

PURPOSE:To obtain a refrigerating air conditioner in which the optimum operation can be always conducted even if the refrigerant composition of non- azeotrope refrigerant circulated in a refrigerating cycle is altered. CONSTITUTION:A refrigerating cycle is composed by coupling a compressor 1, a four-way valve 31, a first heat exchanger 32, first expansion valves 3a, 3b, second heat exchangers 41a, 41b and an accumulator 5. Tubes between the exchanger 32 and the valves 3a, 3b are connected to the accumulator 5 by a bypass tube 50 via a second expansion valve 51, the temperature and the pressure of the refrigerant at the outlet of the valve 51 and the refrigerant temperature of the inlet of the valve 51 are detected, and the refrigerant composition circulated in the cycle is calculated by a composition calculator 20. Simultaneously, the operation of the cycle is controlled by a controller 21 in response to the circulated composition detected by the calculator 20.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerating and air-conditioning system using a non-azeotropic mixed refrigerant, and particularly to a refrigerating and air-conditioning system which is highly reliable and operates efficiently even when the refrigerant circulation composition is different from the initial filling composition. The present invention relates to the configuration of the device.

[0002]

2. Description of the Related Art FIG. 22 shows a structure of a conventional refrigerating and air-conditioning apparatus using a non-azeotropic mixed refrigerant disclosed in JP-A-61-1546. In the figure, 1 is a compressor, 2 is a condenser, 3 is an expansion valve, 4 is an evaporator, and 5 is an accumulator. A non-azeotropic mixed refrigerant composed of a boiling point component is used.

In the refrigerating and air-conditioning apparatus constructed as described above, the high-temperature and high-pressure refrigerant gas compressed by the compressor 1 is condensed and liquefied by the condenser 2 and decompressed by the expansion valve 3 to form a low-pressure gas-liquid two-phase refrigerant. And flows into the evaporator 4. This refrigerant evaporates in the evaporator 4, returns to the compressor 1 via the accumulator 5, is compressed again, and is sent to the condenser 2. Further, the accumulator 5 prevents the liquid from returning to the compressor 1 by accumulating the excess refrigerant generated due to the operating condition and the load condition of the refrigerating air conditioner.

In such a refrigerating and air-conditioning apparatus, by using a non-azeotropic mixed refrigerant as a refrigerant,
It is conventionally known that advantages such as a lower evaporation temperature or a higher condensation temperature which cannot be obtained with a single refrigerant or a higher cycle efficiency can be obtained. In addition, R1 which has been widely used from the past
Since refrigerants such as 2 and R22 cause ozone layer destruction, non-azeotropic mixed refrigerants have been proposed as alternative refrigerants for these.

[0005]

Since the conventional refrigerating and air-conditioning apparatus using the non-azeotropic mixed refrigerant is constructed as described above, if the operating conditions and load conditions of the refrigerating and air-conditioning apparatus are constant, the refrigerating cycle The composition of the refrigerant circulating inside is constant,
The efficient refrigeration cycle as described above is configured. However, when operating conditions and load conditions change, especially when the amount of refrigerant stored in the accumulator changes, the refrigerant composition that circulates in the refrigeration cycle changes, and control of the refrigeration cycle according to this circulating refrigerant composition, that is, the compressor It is necessary to adjust the flow rate of the refrigerant by controlling the number of revolutions, controlling the opening of the expansion valve, or the like.
However, the conventional refrigerating air conditioner has a problem that it is not possible to maintain the optimum operation according to the circulating refrigerant composition because the means for detecting the circulating refrigerant composition is not provided. Even if the circulating refrigerant composition changes due to refrigerant leakage during use of the refrigeration cycle or malfunction during charging of the refrigerant, this abnormality in the circulating refrigerant composition cannot be detected, and the safety and reliability of the refrigeration air conditioning system is high. There was a problem that was not obtained.

The present invention has been made in order to solve the above problems, and provides a refrigerating air-conditioning apparatus that always enables an optimal refrigerating cycle operation even if the composition of the refrigerant circulating in the refrigerating cycle changes. The purpose is to get.

[0007]

A refrigeration air conditioner using a non-azeotropic mixed refrigerant according to claim 1 of the present invention constitutes a refrigeration cycle by connecting a compressor, a condenser, an expansion valve and an evaporator. The temperature and pressure of the refrigerant at the evaporator inlet,
And a composition calculator for calculating the refrigerant composition circulating in the cycle by detecting the refrigerant temperature at the outlet of the condenser,
A control device for controlling the operation of the refrigeration cycle in accordance with the circulation composition detected by the composition calculator is provided.

A refrigeration air-conditioning apparatus using a non-azeotropic mixed refrigerant according to a second aspect of the present invention constitutes a refrigeration cycle by connecting a compressor, a condenser, an expansion valve, and an evaporator. A control is provided to detect the temperature and pressure of the refrigerant at the inlet and provide a composition calculator for calculating the composition of the refrigerant circulating in the cycle, and to control the operation of the refrigeration cycle in accordance with the circulation composition detected by the composition calculator. A device is provided.

In a refrigerating air-conditioning system using a non-azeotropic mixed refrigerant according to a third aspect of the present invention, a refrigerating cycle is constituted by connecting a compressor, a condenser, an expansion valve, an evaporator and an accumulator, A composition calculator for calculating the refrigerant composition circulating in the cycle by detecting the temperature and pressure of the refrigerant in the accumulator or between the accumulator and the compressor suction pipe, and the circulation composition detected by this composition calculator A control device for controlling the compressor and the expansion valve according to the above is provided.

According to a fourth aspect of the present invention, there is provided a refrigerating and air-conditioning apparatus using a non-azeotropic mixed refrigerant, which comprises a refrigerating cycle by connecting a compressor, a condenser, an expansion valve, an evaporator and an accumulator. A composition calculator that detects the liquid level of the accumulator and calculates the refrigerant composition that circulates in the cycle is provided, and a control device that controls the operation of the refrigeration cycle according to the circulation composition detected by this composition calculator is provided. It is a thing.

According to a fifth aspect of the present invention, in a refrigerating and air-conditioning system using a non-azeotropic mixed refrigerant, a compressor, a four-way valve, a first heat exchanger, a first expansion valve, and a second heat exchanger are connected. In a refrigerating cycle, the pipe between the first heat exchanger and the first expansion valve and the suction pipe of the compressor are connected by a bypass pipe via the second expansion valve, A composition calculator for calculating the refrigerant composition circulating in the cycle by detecting the temperature and pressure of the refrigerant at the outlet and the refrigerant temperature at the inlet of the second expansion valve and being detected by this composition calculator A control device for controlling the operation of the refrigeration cycle according to the circulation composition is provided.

According to a sixth aspect of the present invention, there is provided a refrigeration / air-conditioning system using a non-azeotropic mixed refrigerant, which comprises a compressor, a four-way valve, a first heat exchanger, a first expansion valve, and a second heat exchanger connected to each other. In a refrigerating cycle, the pipe between the first heat exchanger and the first expansion valve and the suction pipe of the compressor are connected by a bypass pipe via the second expansion valve, A composition calculator that detects the temperature and pressure of the refrigerant at the outlet and calculates the refrigerant composition circulating in the cycle is provided, and the operation of the refrigeration cycle is controlled according to the circulation composition detected by this composition calculator. A control device is provided.

According to a seventh aspect of the present invention, there is provided a refrigerating and air-conditioning apparatus using a non-azeotropic mixed refrigerant, wherein a bypass pipe in the refrigerating and air-conditioning apparatus according to the fifth or sixth aspect is provided between the first heat exchanger and the first expansion valve. The heat exchanging section for exchanging heat with the pipe is provided.

A refrigerating and air-conditioning apparatus using a non-azeotropic mixed refrigerant according to claim 8 of the present invention,
A comparison calculation means for issuing a warning signal when the circulating composition detected by the composition calculation device is out of a predetermined range, and an alarm means for operating according to an alarm signal issued by the comparison calculation means are provided.

[0015]

According to the first aspect of the present invention, the composition of the refrigerant circulating in the refrigeration cycle in which the compressor, the condenser, the expansion valve and the evaporator are connected is determined by the temperature and pressure of the refrigerant at the evaporator inlet,
Also, the refrigerant temperature at the outlet of the condenser is detected, and the detected value is input to the composition calculator for calculation. The refrigerant circulation composition detected by the composition calculator is input to the control device, and the control values for the compressor, expansion valve, etc. are determined according to the refrigerant circulation composition. Even if the composition changes, or if the circulation composition changes due to a refrigerant leak during use of the refrigeration air conditioner or a malfunction during charging of the refrigerant, it is possible to enable optimum operation of the refrigeration air conditioner.

In the second aspect of the present invention, only the temperature and pressure of the refrigerant at the inlet of the evaporator in the refrigeration cycle are input to the composition calculator, and the dryness of the refrigerant flowing into the evaporator is predetermined in the composition calculator. The refrigerant composition is calculated assuming that Therefore, the same device as the above device can be realized with a simple device configuration.

According to a third aspect of the present invention, in a refrigeration cycle in which a compressor, a condenser, an expansion valve, an evaporator, and an accumulator are connected, a refrigerant temperature in the accumulator or between the accumulator and the compressor suction pipe is set. The pressure is detected, the detected value is input to the composition calculator, and the composition calculator calculates the refrigerant composition on the assumption that the dryness of the refrigerant flowing into the accumulator is a predetermined value. Therefore, similar to the above-mentioned device, the refrigeration / air-conditioning device can be optimally operated with a simple device configuration even when the circulation composition changes.

According to a fourth aspect of the present invention, the liquid level of the accumulator is detected, and the detection signal is input to the composition calculator. From the relationship between the liquid level height and the circulating composition, which has been examined in advance by the composition calculator, Calculate the refrigerant composition. Therefore, similar to the above-mentioned device, the refrigeration / air-conditioning device can be optimally operated with a simple device configuration even when the circulation composition changes.

According to the fifth and sixth aspects of the present invention, in the refrigeration cycle in which the compressor, the four-way valve, the first heat exchanger, the first expansion valve, and the second heat exchanger are connected, the first heat exchanger is used. And a first expansion valve, and a bypass pipe that connects the suction pipe of the compressor via the second expansion valve, and a temperature detector and a pressure detector are provided therein to calculate the refrigerant composition. . In such a configuration, the downstream side of the second expansion valve is always in a low-pressure two-phase state, so that the refrigerant composition can be known from the temperature and pressure detected by the same detector regardless of cooling or heating.

According to the seventh aspect of the present invention, a heat exchange section is provided in the bypass pipe, and the enthalpy of the refrigerant flowing through the bypass pipe is transmitted to the refrigerant flowing through the main pipe to prevent energy loss.

According to the eighth aspect of the present invention, when the refrigerant circulation composition detected by the composition calculator is out of a predetermined range, it is judged by the comparison calculation means to activate the alarm means. , It is possible to reliably detect that the circulation composition of the non-azeotropic mixed refrigerant changes due to refrigerant leakage during use, or that the circulation composition has changed due to malfunction during refrigerant charging, providing a highly safe and reliable refrigeration air conditioner. Is possible.

[0022]

【Example】

Example 1. Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a first embodiment of a refrigerating and air-conditioning apparatus according to the present invention, in which 1 is a compressor, 2 is a condenser, 3 is an electric expansion valve, 4 is an evaporator, and 5 is an accumulator. Of the electric expansion valve 3 is controlled by an output signal of the control device 21. This refrigeration cycle is filled with a non-azeotropic mixed refrigerant composed of, for example, a high boiling point component R134a and a low boiling point component R32.

At the inlet of the evaporator 4, the refrigerant temperature T1
Is provided with a first temperature detector 11 for detecting the refrigerant pressure and a first pressure detector 12 for detecting the refrigerant pressure P1, and at the outlet of the condenser 2, a second temperature detector for detecting the refrigerant temperature T2 is provided. A detector 13 is provided and these detectors 1
The detection signals 1, 12, and 13 are input to the composition calculator 20. Further, the discharge pipe of the compressor 1 is provided with a second pressure detector 14 for detecting the pressure of the refrigerant, and the detection signal of this detector 14 is input to the control device 21 together with the detection signal of the detector 13. It

The composition calculator 20 comprises detectors 11, 12, 1
3 has a function of calculating the circulation composition α of the non-azeotropic mixed refrigerant based on the temperature T1, the pressure P1 and the temperature T2 detected, and the calculated value of the circulation composition α is input to the control device 21. Further, the control device 21 has a function of calculating the saturated liquid temperature TL at the condensing pressure from the circulation composition α and the pressure P2 detected by the detector 14, and the condenser 2 from the saturated liquid temperature TL and the temperature T2 detected by the detector 13. It has a function of calculating the degree of supercooling at the outlet portion of and the function of controlling the opening degree of the electric expansion valve 3 so that the degree of supercooling becomes a predetermined value.

Next, the operation of this embodiment configured as described above will be described. The high-temperature and high-pressure refrigerant gas compressed by the compressor 1 is condensed and liquefied by the condenser 2, decompressed by the expansion valve 3, and becomes a low-pressure gas-liquid two-phase refrigerant and flows into the evaporator 4.
This refrigerant evaporates in the evaporator 4, returns to the compressor 1 via the accumulator 5, is compressed again, and is sent to the condenser 2. Excessive refrigerant generated due to operating conditions and load conditions of the refrigerating and air-conditioning apparatus accumulates in the accumulator 5.

Next, the operation of the composition calculator 20 will be described with reference to the flow chart shown in FIG. 2 and the pressure of the refrigeration cycle shown in FIG.
Description will be made based on the enthalpy diagram and the vapor-liquid equilibrium diagram of the non-azeotropic mixed refrigerant of FIG. In FIG. 3, a solid line A is a saturated liquid curve with respect to the circulating composition α, a solid line B is a saturated vapor curve with respect to the circulating composition α, a solid line C is a cycle operation line, and a chain line is an isotherm. In FIG. 4, the horizontal axis represents the weight fraction of the low boiling point component, the vertical axis represents the temperature, the dotted line represents the saturated vapor temperature (X = 1) when the pressure at the inlet of the evaporator 4 is P1, and the dashed line represents the saturation. The liquid temperature (X = 0), and the solid line is the temperature at dryness X (0 <X <1). When the operation of the composition calculator 20 is started, first, in step S1, the detectors 11, 12, 1 are detected.
The refrigerant temperature T1 and pressure P1 at the inlet of the evaporator 4 and the temperature T2 at the outlet of the condenser 2 detected in Step 3 are used as the composition calculator 2
Capture to 0. Next, in step S2, the circulation composition α in the refrigeration cycle is assumed, and in step S3, the dryness X of the refrigerant flowing into the evaporator 4 is calculated under this assumption.
That is, under the circulation composition α assumed as shown in FIG. 3, the enthalpy H is obtained from the temperature T2 at the outlet of the condenser 2, and _HL is obtained from the pressure P1 at the inlet of the evaporator 4, and the evaporator 4 is obtained. The dryness X of the inlet part of is approximately uniquely determined by the following equation.

[0027]

[Equation 1]

Here, H _V is the enthalpy at the point where the saturated vapor curve and the cycle operation line intersect. Actually dryness X
The relationship between the temperature T2 and the pressure P1 is calculated in advance by the composition calculator 2
It is stored in 0 and the dryness X is calculated using the values of the temperature T2 and the pressure P1. Further, in step S4, the circulation composition α ^* is calculated from the dryness X at the inlet of the evaporator 4, the refrigerant temperature T1 at the inlet of the evaporator 4, and the pressure P1. That is, the temperature and pressure of the gas-liquid two-phase non-azeotropic mixed refrigerant having a dryness of X are determined by the circulation composition flowing in the refrigeration cycle as shown in FIG. Therefore, the circulation composition α ^* can be calculated by using the characteristics shown by the solid line in FIG. In step S5, the circulation composition α ^* is compared with the initially assumed circulation composition α, and if both agree, the circulation composition is obtained as α. If they do not match, the process returns to step S2 and the circulation composition α
Re-estimate and continue the calculation until they match.

Next, the operation of the control device 21 will be described with reference to the flowchart shown in FIG. When the operation of the control device 21 is started, first, in step S1, the temperature T2 at the outlet of the condenser 2 and the condensation pressure P2 are detected. Next, in step S2, the circulating composition α is fetched from the composition calculator 20,
In step S3, the saturated liquid temperature TL at the pressure P2 is calculated from the condensing pressure P2 and the circulation composition α. The saturated liquid temperature TL is determined by the pressure P2 because the circulating composition α is determined.
It is more uniquely determined (see FIG. 3). Further step S4
Then, the refrigerant supercooling degree SC at the outlet of the condenser 2 is calculated from T2 and TL (SC = TL-T2). In step S5, it is determined whether or not the degree of supercooling SC matches a predetermined value, for example, 5 ° C., and when it is determined that it matches the predetermined value, the process proceeds to the end step. When it is determined that the value does not match the predetermined value, the process proceeds to step S6, and the opening degree changing process of the electric expansion valve 3 is executed.

By repeating the above operation, when the circulation composition in the refrigeration cycle changes due to changes in the operating conditions and load conditions of the refrigeration / air-conditioning system, or when the refrigerant leaks during use of the refrigerating / air-conditioning system or when the refrigerant is charged. Even if the circulation composition changes due to a malfunction, the degree of supercooling at the outlet of the condenser 2 is maintained at an appropriate value, and optimum operation can always be performed.

In this embodiment, the two-component system is described as the mixed refrigerant, but the same effect can be obtained in the case of a multi-component system such as a three-component system.

Further, in the control device 21 of this embodiment, the opening degree of the electric expansion valve 3 is controlled so that the degree of supercooling at the outlet of the condenser 2 is kept constant even if the circulating composition in the cycle changes. As described above, the temperature at the outlet of the evaporator 4 is detected, the saturated vapor temperature Tv at the pressure P1 is calculated from the circulating composition α and the evaporation pressure P1 (see FIG. 3), and the evaporator 4
Even if the superheat degree of the outlet of the above is controlled to be constant, the optimum operation of the refrigerating and air-conditioning apparatus can be enabled in the same manner as above.

Further, in this embodiment, the control device 21 has been described as the one which optimally controls the opening degree of the electric expansion valve 3 even if the circulation composition in the cycle changes. Even if it is controlled according to the circulation composition, the same effect can be obtained.

Embodiment 2 FIG. FIG. 6 shows a second embodiment of the refrigerating and air-conditioning apparatus according to the present invention. At the inlet of the evaporator 4, a first temperature detector 11 for detecting the refrigerant temperature T1 and a first refrigerant pressure P1 are provided. The 1st pressure detector 12 which detects is provided, respectively, and these detectors 11 and 12 detection signals are inputted into composition operation machine 20. A second temperature detector 13 for detecting the refrigerant temperature T2 is provided at the outlet of the condenser 2.
Is provided, and the discharge pipe of the compressor 1 is provided with a second pressure detector 14 for detecting the refrigerant pressure. The detection signals of these detectors 13 and 14 are the control device 2
Input to 1.

The composition calculator 20 has a function of calculating the circulating composition α of the non-azeotropic mixed refrigerant based on the temperature T1 and the pressure P1 detected by the detectors 11 and 12, and the circulating composition α The calculated value of is input to the control device 21. Further, the control device 21 has a function of calculating the saturated liquid temperature TL at the condensing pressure from the circulation composition α and the pressure P2 detected by the detector 14, and the condenser 2 from the saturated liquid temperature TL and the temperature T2 detected by the detector 13. It has a function of calculating the degree of supercooling of the outlet portion of and the function of controlling the opening degree of the electric expansion valve 3 so that the degree of supercooling becomes a predetermined value.

Next, the operation of the composition calculator 20 of this embodiment will be described. The composition calculator 20 first takes in the temperature T1 and pressure P1 at the inlet of the evaporator 4. The refrigerant flowing into the evaporator 4 is normally in a gas-liquid two-state with a dryness of about 0.1 to 0.3. By assuming the dryness to be 0.2, for example, the temperature T1 and the pressure P1 are set. The circulation composition α can be estimated only by the information. That is, by using the characteristics shown by the solid line in FIG. 4, the temperature T1 and the pressure P1 are
The circulation composition α can be calculated from

The operation of the control device 21 is the same as that of the first embodiment, and therefore its explanation is omitted. However, in this embodiment, the circulation composition in the refrigeration cycle is determined only by the temperature and pressure at the inlet of the evaporator 4. Is detected, the degree of supercooling at the outlet of the condenser 2 is maintained at an appropriate value even if the circulating composition changes, and optimum operation is always possible.

The set value of the dryness X is about 0.1 to 0.3 in the above embodiment, but is not limited to the above value.

With such a configuration, the calculation by the composition calculator 20 is simplified, the same device as the above can be realized with a simple device structure, and the cost is reduced.

Example 3. FIG. 7 shows a third embodiment of the refrigerating and air-conditioning apparatus according to the present invention. Inside the accumulator 5, there is a first temperature detector 11 for detecting the refrigerant temperature T1 and a pressure detection for detecting the refrigerant pressure P1. Each of the detectors 12 is provided, and the detection signals of the detectors 11 and 12 are input to the composition calculator 20. The composition calculator 20 has a function of calculating the circulation composition α of the non-azeotropic mixed refrigerant based on the temperature T1 in the accumulator 5 and the pressure P1 detected by the detectors 11 and 12. The operation of the composition calculator 20 will be described.

In the arithmetic controller 20, first, the detectors 11 and 1
The refrigerant temperature T1 and pressure P1 in the accumulator 5 detected in 2 are taken in. The refrigerant flowing into the accumulator 5 is usually in a gas-liquid two-phase state having a dryness of about 0.8 to 1.0, but the dryness can be approximately regarded as 0.9. The temperature and pressure of the refrigerant in this state are determined by the circulating composition of the non-azeotropic mixed refrigerant flowing in the refrigeration cycle as shown in FIG. Therefore, by using the characteristic shown by the solid line in FIG.
, And the pressure P1 alone, the circulation composition α can be calculated.

Since the operation of the control device 21 is the same as that of the first embodiment, a description thereof will be omitted. However, in this embodiment, the circulation composition in the refrigeration cycle is detected only by the temperature and pressure in the accumulator 5. It is possible to
The calculation by the composition calculator 20 is simple, and the device similar to that of the first embodiment can be obtained at a low cost with a simple device configuration.

In this embodiment, the temperature and pressure in the accumulator 5 are measured, but the first temperature detector 11 and the pressure detector 12 are provided between the accumulator 5 and the suction pipe of the compressor 1. It may be provided. Further, although the set value of the dryness X is set to about 0.8 to 1.0 in the above embodiment, the set value is not limited to the above value.

Example 4. FIG. 9 shows a fourth embodiment of the refrigerating and air-conditioning apparatus according to the present invention. The accumulator 5 is provided with a liquid level detector 15 for detecting the liquid level of the refrigerant inside the accumulator 5, and this liquid level is further provided. The signal of the detector 15 is input to the composition calculator 20. As the liquid level detector 15, for example, a known liquid level gauge such as an ultrasonic type liquid level gauge or a capacitance type liquid level gauge is used. The composition calculator 20 includes a detector 15
Has a function of calculating the circulation composition α of the non-azeotropic mixed refrigerant on the basis of the refrigerant liquid level height h in the accumulator 5 detected by the above. The operation of the composition calculator 20 will be described below.

When the operation of the composition calculator 20 is started, first, the refrigerant liquid level height h in the accumulator 5 detected by the liquid level detector 15 is fetched. Generally, the refrigerant in the accumulator of a refrigeration cycle using a non-azeotropic mixed refrigerant is separated into a liquid phase rich in high boiling point components and a gas phase rich in low boiling point components, and a liquid phase rich in high boiling point components is It is stored in the accumulator. Therefore, when the liquid refrigerant is present in the accumulator, the refrigerant composition circulating in the refrigeration cycle tends to have a large amount of low-boiling components (the circulation composition increases). FIG. 10 shows the relationship between the refrigerant liquid level height h in the accumulator and the circulation composition α. As the refrigerant liquid level height in the accumulator increases, that is, as the amount of liquid refrigerant in the accumulator increases, the circulation The composition increases. Therefore, this FIG.
If you check the relationship shown in 0 by experiments in advance,
The circulation composition α can be calculated from the refrigerant liquid level height h in the accumulator 5 detected by the liquid level detector 15.

Since the operation of the control device 21 is the same as that of the first embodiment, its explanation is omitted, but in this embodiment, the circulation composition in the refrigerating cycle is determined only by the liquid level of the refrigerant in the accumulator 5. It can be detected, the device configuration is simple, and even if the circulating composition changes, the degree of supercooling at the outlet of the condenser 2 is maintained at an appropriate value, and optimum operation can always be performed.

In the above embodiment, the liquid level detecting means 15
The case where a liquid level gauge such as an ultrasonic type or a capacitance type is used has been described above. However, the excess refrigerant amount in the cycle is calculated based on the operating conditions and load conditions of the refrigeration cycle, and the liquid in the accumulator 5 is calculated. The same effect is exhibited even if the surface height is detected. For example, during cooling operation, no excess refrigerant is generated, during heating operation, a certain amount of excess refrigerant is generated, it has been investigated in advance by experiments, etc., and the relationship between this operation condition and the excess refrigerant amount measured in advance, The liquid level height in the accumulator 5 may be detected by calculation. At this time, information such as the indoor air temperature and the outdoor air temperature during the cooling and heating operation may be added to improve the liquid level detection accuracy in the accumulator.

Example 5. FIG. 11 shows a fifth embodiment of the refrigerating and air-conditioning apparatus according to the present invention, showing a refrigerating and air-conditioning apparatus in which two outdoor units are connected to one outdoor unit. In FIG. 11, reference numeral 30 denotes an outdoor unit, which includes a compressor 1, a four-way valve 31, an outdoor heat exchanger (first heat exchanger) 32, an outdoor blower 33, and an accumulator 5, and a discharge side of the compressor 1. A second pressure detector 14 is provided in the pipe. 40a, 40b (hereinafter, when collectively referred to as 40) are indoor units, and indoor heat exchanger (second heat exchanger) 41a,
Or 41b (hereinafter, collectively referred to as 41) and the first expansion valve, an electric expansion valve 3a or 3b (hereinafter, collectively referred to as 3), which is provided at the inlet / outlet portion of the indoor heat exchanger 41. Are the third temperature detectors 42a and 42b (hereinafter,
When collectively referred to as 42), and the fourth temperature detectors 43a, 43
b (hereinafter, 43 when collectively referred to) is provided. Further, a bypass pipe 50 connecting this pipe and the accumulator 5 is provided in the middle of the pipe connecting the outdoor heat exchanger 32 and the electric expansion valve 3 in the indoor unit 40, and in the middle of the bypass pipe 50. Is provided with a capillary tube 51 which is a second expansion valve. In the bypass pipe 50, the first temperature detector 11 and the first pressure detector 1 are provided at the outlet of the capillary 51.
2 is provided, and a second portion is provided at the entrance of the capillary tube 51.
A temperature detector 13 is provided. The indoor blower is omitted.

Reference numeral 20 denotes a composition calculator, which is a bypass pipe 5
No. 1, first temperature detector 11 and first pressure detector 1
2. The signal from the second temperature detector 13 is input to calculate the composition of the refrigerant circulating in the cycle. Reference numeral 21 is a control device, and the circulating composition signal from the composition calculator 20, the first pressure detector 12, the second pressure detector 14, and the third inside the indoor unit 40.
The signals from the temperature detector 42 and the fourth temperature detector 43 are input. In the control device 21, these input signals are
The rotation speed of the compressor 1 and the rotation speed of the outdoor blower 33 according to the circulation composition, and the opening degree of the electric expansion valve 3 of the indoor unit are calculated, and the command is given to the compressor 1, the outdoor blower 33, and the electric expansion valve 3 To send to each. In the compressor 1, the outdoor blower 33, and the electric expansion valve 3, the command value sent from the control device 21 is received, and the rotation speed and valve opening degree are driven. Reference numeral 22 denotes a comparison calculation means, which receives a circulation composition signal from the composition calculation device 20 and performs comparison calculation on whether or not the circulation composition is within a predetermined range. An alarm device 23 is connected to the comparison calculation means 22, and when the circulating composition is out of a predetermined range, an alarm signal is transmitted to the alarm device 23.

Next, the operation of this embodiment configured as described above will be described with reference to the control block diagrams shown in FIGS. 11 and 12. The composition calculator 20 includes a first temperature detector 11 and a first pressure detector 1 provided in the bypass pipe 50.
2, capturing the signal from the second temperature detector 13,
And the dryness X of the refrigerant at the inlet of the capillary tube 51 is calculated using the relationship shown in FIG. 4 to calculate the circulation composition α in the cycle. The control device 21 calculates the optimum rotation speed command of the compressor 1, the rotation speed command of the outdoor blower 33, and the opening degree command of the electric expansion valve 3 according to the circulation composition α.

First, the heating operation will be described. During the heating operation, the refrigerant circulates in the direction of the solid arrow in FIG. 11, and the indoor heat exchanger 41 serves as a condenser for heating. The rotation speed of the compressor 1 is controlled so that the condensing pressure matches the target value, and the condensing pressure target value is obtained as a pressure at which the condensing temperature Tc becomes 50 ° C., for example. If the condensation temperature of the non-azeotropic mixed refrigerant is defined as the average value of the saturated vapor temperature and the saturated liquid temperature, the condensation pressure target value Pc at which the condensation temperature Tc becomes 50 ° C.
Is uniquely determined by the circulation composition α, as shown in FIG. Therefore, in the controller 21, the relational expression of FIG. 13 is stored in advance, and the condensing pressure target value is calculated using the circulating composition signal transmitted from the composition calculator 20. Further, in the control device 21, the correction value of the rotation speed of the compressor 1 is calculated by feedback control such as PID control according to the difference between the pressure detected by the second pressure detector 14 and the condensing pressure target value, and the compressor is operated. The rotation speed command is output to the compressor 1.

The rotation speed of the outdoor blower 33 is controlled so that the evaporation pressure matches the target value, and this evaporation pressure target value is obtained as a pressure at which the evaporation temperature Te becomes 0 ° C., for example. When the evaporation temperature of the non-azeotropic mixed refrigerant is defined as the average value of the saturated vapor temperature and the saturated liquid temperature, the evaporation pressure target value Pe at which the evaporation temperature Te becomes 0 ° C. is determined by the circulation composition α as shown in FIG. It is uniquely determined. Therefore, in the control device 21,
The relational expression of FIG. 14 is stored in advance, and the composition calculator 20
The target evaporation pressure value is calculated by using the circulation composition signal transmitted from. Further, in the control device 21, the correction value of the rotation speed of the outdoor blower 33 is calculated by feedback control such as PID control according to the difference between the pressure detected by the first pressure detector 12 and the evaporation pressure target value, and the outdoor blower is calculated. The rotation speed command is output to the outdoor blower 33.

The opening degree of the electric expansion valve 3 is the same as that of the indoor heat exchanger 4.
The degree of supercooling at the outlet of No. 1 is controlled to a predetermined value, for example, 5 ° C. This degree of supercooling can be obtained as the difference between the saturated liquid temperature at the pressure inside the indoor heat exchanger 41 and the temperature at the outlet of the indoor heat exchanger 41, and the saturated liquid temperature corresponds to the pressure as shown in FIG. It can be determined as a function of circulation composition. Therefore, in the control device 21, the relational expression of FIG. 15 is stored in advance, and the circulating composition signal transmitted from the composition calculator 20, the pressure signal transmitted from the second pressure detector 14, and the third temperature detector 42. The saturated liquid temperature and the outlet supercooling degree of the indoor heat exchanger 41 are calculated using the temperature signal transmitted from the. Further, in the control device 21, the P value corresponding to the difference between the supercooling degree at the outlet and the predetermined value (5 ° C.) is set.
Electric expansion valve 3 by feedback control such as ID control
The correction value of the opening of is calculated, and the electric expansion valve opening command is output to the electric expansion valve 3.

On the other hand, during the cooling operation, the refrigerant circulates in the direction of the broken arrow in FIG. 11, and the indoor heat exchanger 41 serves as an evaporator for cooling. The rotation speed of the compressor 1 is controlled so that the evaporation pressure matches a target value, and this evaporation pressure target value is obtained as a pressure at which the evaporation temperature Te becomes 0 ° C., for example. When the evaporation temperature of the non-azeotropic mixed refrigerant is defined as the average value of the saturated vapor temperature and the saturated liquid temperature, the evaporation pressure target value Pe at which the evaporation temperature Te becomes 0 ° C. is determined by the circulation composition α as shown in FIG. It is uniquely determined. Therefore, in the control device 21,
The relational expression of FIG. 14 is stored in advance, and the composition calculator 20
The target evaporation pressure value is calculated by using the circulation composition signal transmitted from. Further, the control device 21 performs feedback control such as PID control according to the difference between the pressure detected by the first pressure detector 12 and the evaporation pressure target value, and the compressor 1
The corrected value of the rotation speed is calculated, and the compressor rotation speed command is output to the compressor 1.

The rotation speed of the outdoor blower 33 is controlled so that the condensing pressure matches the target value, and this condensing pressure target value is obtained as a pressure at which the condensing temperature Tc becomes 50 ° C., for example. When the condensation temperature of the non-azeotropic mixed refrigerant is defined as the average value of the saturated vapor temperature and the saturated liquid temperature, the condensation pressure target value Pc at which the condensation temperature Tc becomes 50 ° C. is determined by the circulation composition α as shown in FIG. It is uniquely determined. Therefore, in the controller 21, the relational expression of FIG. 13 is stored in advance, and the condensing pressure target value is calculated using the circulating composition signal transmitted from the composition calculator 20. Further, in the control device 21, the correction value of the rotation speed of the outdoor blower 33 is calculated by feedback control such as PID control according to the difference between the pressure detected by the second pressure detector 14 and the condensing pressure target value, and the outdoor blower is calculated. The rotation speed command is output to the outdoor blower 33.

The opening degree of the electric expansion valve 3 is the same as that of the indoor heat exchanger 4.
The degree of superheat at the outlet of No. 1 is controlled to a predetermined value, for example, 5 ° C. This degree of superheat can be obtained as the difference between the saturated steam temperature at the pressure inside the indoor heat exchanger 41 and the temperature at the outlet of the indoor heat exchanger 41, and the saturated steam temperature is equal to the saturated liquid temperature shown in FIG. Similarly, it can be obtained as a function of pressure and circulation composition. Therefore, in the control device 21,
A relational expression of saturated vapor temperature, pressure and circulation composition is stored in advance, and a circulation composition signal transmitted from the composition calculator 20, a pressure signal transmitted from the first pressure detector 12, and a fourth
The saturated steam temperature and the outlet superheat degree of the indoor heat exchanger 41 are calculated using the temperature signal transmitted from the temperature detector 43. Further, in the control device 21, the correction value of the opening degree of the electric expansion valve 3 is calculated by feedback control such as PID control according to the difference between the outlet superheat degree and the predetermined value (5 ° C.), and the electric expansion is performed. A valve opening command is output to the electric expansion valve 3.

Next, the operation of the comparison calculation means 22 will be described. The comparison calculation means 22 takes in the circulation composition signal from the composition calculator 20, determines whether or not this circulation composition is within a proper circulation composition range stored in advance, and the circulation composition is within the proper circulation composition range. If so, the operation continues. On the other hand, when the circulation composition changes due to refrigerant leakage during use, or when the circulation composition changes due to an erroneous operation at the time of charging the refrigerant, the comparison calculation means 22 determines that this circulation composition is outside the pre-stored proper circulation composition range. If it is determined that, the alarm signal is transmitted to the alarm device 23. The alarm device 23 that has received this alarm signal issues a warning for a predetermined time to warn that the circulation composition of the non-azeotropic mixed refrigerant of the refrigerating and air-conditioning device is out of the proper range.

As described above, according to the present embodiment,
Regardless of cooling or heating, the downstream side of the second expansion valve is always in a low-pressure two-phase state, so the temperature and pressure can be measured with the same detector during cooling and heating, and the refrigerant composition is calculated. can do. Therefore, it is not necessary to provide a detector separately for cooling and heating, the device configuration is simplified, and even if the circulating composition changes, optimum operation can always be performed.

In this embodiment, the number of rotations of the outdoor blower 33 during heating operation is controlled so that the value of the first pressure detector 12 matches the evaporation pressure target value calculated from the circulation composition. However, the same effect can be obtained by providing a temperature detector at the inlet of the outdoor heat exchanger 33 and controlling the temperature to be a predetermined value (for example, 0 ° C.).

In this embodiment, the opening degree of the electric expansion valve 3 during the cooling operation is controlled so that the superheat degree at the outlet of the indoor heat exchanger 41 becomes a predetermined value (for example, 5 ° C.). However, the inlet / outlet temperature difference of the indoor heat exchanger 41 has a predetermined value (for example, 10 ° C.), that is, the temperature difference between the fourth temperature detector and the third temperature detector has a predetermined value. Even if it is controlled to, the same effect can be obtained.

Further, in the present embodiment, the description has been given of the refrigerating and air-conditioning system in which two indoor units 40 are connected to one outdoor unit 30, but the present invention is not limited to this, and only one indoor unit is connected. The same effect can be obtained even when the indoor unit is connected or three or more indoor units are connected.

Example 6. 16 and 17 show a sixth embodiment of the refrigerating and air-conditioning apparatus according to the present invention.
1 and FIG. 16, elements having the same numbers indicate the same elements. The refrigerant circulates in the direction of the solid arrow in FIG. 16 during the heating operation, and circulates in the direction of the broken arrow during the cooling operation.
In this embodiment, the signal input to the composition calculator 20 is
Only the first temperature detector 11 and the first pressure detector 12,
Refrigerant dryness X flowing into the capillary tube 51 of the bypass pipe 50
Is 0.1 for heating operation and 0. for cooling operation.
Assuming that the first temperature detector 11 and the first pressure detector 1
Only the signal from 2 calculates the circulation composition. Hereinafter, the operations of the control device 21 and the comparison calculation means 22 are the same as in the fifth embodiment.

Therefore, the refrigerating and air-conditioning system according to this embodiment is
As in the case of the second embodiment, the calculation by the composition calculator 20 is simple, and the device similar to that of the fifth embodiment can be realized with a simple device configuration, which is inexpensive.

Example 7. 18 and 19 show a seventh embodiment of the refrigerating and air-conditioning apparatus according to the present invention.
1 and FIG. 18, elements with the same numbers indicate the same elements. The refrigerant circulates in the direction of the solid arrow in FIG. 18 during the heating operation, and in the direction of the dashed arrow during the cooling operation.
The bypass pipe 50 is provided with a second electric expansion valve 51 as a second expansion valve, and the valve opening degree is controlled by the control device 21. A heat exchanging section 52 for exchanging heat with the pipe (main pipe) connecting the outdoor heat exchanger 32 and the first electric expansion valve 3 is provided in the middle of the bypass pipe 50. Since the enthalpy of the flowing refrigerant is transmitted to the refrigerant flowing through the main pipe, the enthalpy is recovered and energy loss is prevented. Further, at the outlet of the heat exchange section 52, the fifth temperature detector 16
Is provided, and this detection signal is sent to the control device 21.

In the control device 21 of this embodiment, only the control method of the second electric expansion valve 51 provided in the bypass pipe 50 is different from that of the sixth embodiment.
The control method 1 will be described. The opening degree of the second electric expansion valve 51 is controlled so that the temperature difference between the inlet and outlet of the heat exchange section 52 provided in the bypass pipe 50 becomes a predetermined value (for example, 10 ° C.). That is, the signals of the first temperature detector 11 and the fifth temperature detector 16 provided in the bypass pipe 51 are transmitted to the control device 21, and the control device 21 controls the first temperature detector 11 and the fifth temperature detector 16 to operate. The temperature difference detected by the CPU is calculated, and the correction value of the opening degree of the second electric expansion valve 51 is calculated by feedback control such as PID control according to the difference between this temperature difference and a predetermined value (for example, 10 ° C.). The electric expansion valve opening command is output to the second electric expansion valve 51.
By doing so, the refrigerant flowing from the bypass pipe 50 to the accumulator 5 is always in a vapor state, energy is effectively used, and liquid return to the compressor 1 can be prevented.

In the above embodiment, the electric expansion valve is used as the second expansion valve 51, but a capillary tube or the like may be used.

Example 8. 20 and 21 show an eighth embodiment of the refrigerating and air-conditioning apparatus according to the present invention.
8 and FIG. 20, the elements with the same numbers indicate the same elements. The refrigerant circulates in the direction of the solid arrow in FIG. 20 during the heating operation, and in the direction of the dashed arrow during the cooling operation.
In this embodiment, the signal input to the composition calculator 20 is
Similar to the second and sixth embodiments, there is only the first temperature detector 11 and the first pressure detector 12, and the refrigerant dryness X flowing into the second electric expansion valve 51 of the bypass pipe 50 is set to, for example, heating. The circulating composition is calculated only by the signals from the first temperature detector 11 and the first pressure detector 12, assuming 0.1 during operation and 0.2 during cooling operation. Hereinafter, the control device 21,
The operation of the comparison calculation means 22 is similar to that of the seventh embodiment.

In the above embodiment, the electric expansion valve is used as the second expansion valve 51, but a capillary tube or the like may be used.

Further, in the above fifth to eighth embodiments,
Although the refrigerating air-conditioning apparatus having the accumulator 5 is shown, it may be omitted. In this case, the bypass pipe 50 is configured to connect the suction pipe of the compressor and the main pipe via the second expansion valve. Furthermore, in the above fifth to eighth embodiments,
The comparison calculation means 22 is connected and is configured to send a warning signal to the alarm device 23 when the circulation composition is out of the predetermined range.
2 and the alarm device 23 may not be provided. Further, the comparison calculation means 22 and the alarm device 23 may be provided for the first to fourth embodiments.

[0070]

As described above, according to claim 1 of the present invention, a non-azeotropic mixed refrigerant is used, and a compressor, a condenser, an expansion valve,
In a refrigerating air-conditioning apparatus that constitutes a refrigeration cycle by connecting an evaporator and a refrigerant, the temperature and pressure of the refrigerant at the evaporator inlet and the refrigerant temperature at the condenser outlet are detected to calculate the refrigerant composition circulating in the cycle. A composition calculator is provided and a control device that controls the operation of the refrigeration cycle in accordance with the circulation composition detected by this composition calculator is provided, so that even if the circulation composition in the cycle changes, optimum operation is always performed. It will be possible.

Further, according to claim 2 of the present invention, in the refrigerating and air-conditioning apparatus that uses the non-azeotropic mixed refrigerant and connects the compressor, the condenser, the expansion valve, and the evaporator to the refrigerating air-conditioning apparatus, A composition calculator for calculating the refrigerant composition circulating in the cycle by detecting the temperature and pressure of the refrigerant at the inlet of the container is provided, and operation control of the refrigeration cycle is performed according to the circulation composition detected by this composition calculator. Since the control device is provided, a simple device configuration has the same effect as the above device.

According to a third aspect of the present invention, in a refrigerating and air-conditioning apparatus that uses a non-azeotropic mixed refrigerant and connects a compressor, a condenser, an expansion valve, an evaporator, and an accumulator to form a refrigeration cycle. , A composition calculator for calculating the refrigerant composition circulating in the cycle by detecting the temperature and pressure of the refrigerant in the accumulator or between the accumulator and the compressor suction pipe, and the circulation detected by this composition calculator Since the control device for controlling the operation of the refrigeration cycle according to the composition is provided, the same effect as the above device can be obtained with a simple device configuration.

According to a fourth aspect of the present invention, in a refrigerating and air-conditioning apparatus that uses a non-azeotropic mixed refrigerant and connects a compressor, a condenser, an expansion valve, an evaporator, and an accumulator to form a refrigeration cycle. , A composition calculator for detecting the liquid level of the accumulator and calculating the refrigerant composition circulating in the cycle, and a control device for controlling the operation of the refrigeration cycle in accordance with the circulation composition detected by the composition calculator Therefore, with a simple device configuration, the same effect as the above device can be obtained.

According to claim 5 of the present invention, the non-azeotropic mixed refrigerant is used, and the compressor, the four-way valve, the first heat exchanger, the first heat exchanger,
In a refrigerating air-conditioning apparatus that forms a refrigeration cycle by connecting an expansion valve and a second heat exchanger, a pipe between the first heat exchanger and the first expansion valve and a suction pipe of the compressor are connected to the second expansion valve. A composition for calculating the refrigerant composition circulating in the cycle by detecting the temperature and pressure of the refrigerant at the outlet of the second expansion valve and the refrigerant temperature at the inlet of the second expansion valve by connecting the bypass piping via the Since a controller is provided to control the operation of the refrigeration cycle according to the circulation composition detected by this composition calculator, optimum operation is always possible even if the circulation composition in the cycle changes. Becomes

According to claim 6 of the present invention, the non-azeotropic mixed refrigerant is used, and the compressor, the four-way valve, the first heat exchanger, the first heat exchanger,
In a refrigerating air-conditioning apparatus that forms a refrigeration cycle by connecting an expansion valve and a second heat exchanger, a pipe between the first heat exchanger and the first expansion valve and a suction pipe of the compressor are connected to the second expansion valve. And a composition calculator for calculating the refrigerant composition circulating in the cycle by detecting the temperature and pressure of the refrigerant at the outlet of the second expansion valve, and detecting by this composition calculator Since the control device for controlling the operation of the refrigeration cycle is provided according to the circulation composition thus obtained, the same effect as that of the above device can be obtained with a simple device configuration.

According to claim 7 of the present invention, the non-azeotropic mixed refrigerant is used, and the compressor, the four-way valve, the first heat exchanger, the first heat exchanger,
In the above-mentioned refrigerating air-conditioning apparatus in which the expansion valve and the second heat exchanger are connected to form a refrigeration cycle, heat exchange is performed in the bypass pipe by heat exchange between the first heat exchanger and the pipe between the first expansion valve. Since the parts are provided, a refrigerating and air-conditioning apparatus with high energy efficiency can be obtained while always being able to perform optimum operation even if the circulation composition in the cycle changes.

According to claim 8 of the present invention, in each of the refrigerating and air-conditioning devices, a comparison calculation means for issuing a warning signal when the circulation composition detected by the composition calculation device is out of a predetermined range, and the comparison calculation means. Since the alarm device that operates according to the alarm signal issued by the calculation means is provided, it is possible to provide a refrigeration and air-conditioning device with high safety and reliability.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a refrigerating and air-conditioning apparatus using a non-azeotropic mixed refrigerant according to a first embodiment of the present invention.

FIG. 2 is a flowchart showing the operation of the composition calculator according to the first embodiment of the present invention.

FIG. 3 is an explanatory diagram for explaining the operation of the composition calculator according to the first embodiment of the present invention using a pressure-enthalpy line.

FIG. 4 is an explanatory diagram for explaining the operation of the composition calculator according to the first embodiment of the present invention by using the relationship between the temperature of the non-azeotropic mixed refrigerant and the circulating composition.

FIG. 5 is a flowchart showing the operation of the control device according to the first embodiment of the present invention.

FIG. 6 is a configuration diagram showing a refrigerating and air-conditioning apparatus using a non-azeotropic mixed refrigerant according to a second embodiment of the present invention.

FIG. 7 is a configuration diagram showing a refrigerating and air-conditioning apparatus using a non-azeotropic mixed refrigerant according to a third embodiment of the present invention.

FIG. 8 is an explanatory diagram for explaining the operation of the composition calculator according to the third embodiment of the present invention by using the relationship between the temperature of the non-azeotropic mixed refrigerant and the circulating composition.

FIG. 9 is a configuration diagram showing a refrigerating and air-conditioning apparatus using a non-azeotropic mixed refrigerant according to a fourth embodiment of the present invention.

FIG. 10 is an explanatory diagram for explaining the operation of the composition calculator according to the fourth embodiment of the present invention, using the relationship between the refrigerant liquid level in the accumulator and the circulating composition.

FIG. 11 is a configuration diagram showing a refrigerating and air-conditioning apparatus using a non-azeotropic mixed refrigerant according to a fifth embodiment of the present invention.

FIG. 12 is a control block diagram of a refrigerating and air-conditioning apparatus using a non-azeotropic mixed refrigerant according to a fifth embodiment of the present invention.

FIG. 13 is an explanatory diagram for explaining the operation of the control device according to the fifth embodiment of the present invention by using the relationship between the condensing pressure of the non-azeotropic mixed refrigerant and the circulating composition.

FIG. 14 is an explanatory diagram for explaining the operation of the control device according to the fifth embodiment of the present invention by using the relationship between the evaporation pressure of the non-azeotropic mixed refrigerant and the circulation composition.

FIG. 15 is an explanatory diagram for explaining the operation of the control device according to the fifth embodiment of the present invention by using the relationship between the saturated liquid temperature, the pressure, and the circulation composition of the non-azeotropic mixed refrigerant.

FIG. 16 is a configuration diagram showing a refrigerating and air-conditioning apparatus using a non-azeotropic mixed refrigerant according to a sixth embodiment of the present invention.

FIG. 17 is a control block diagram of a refrigerating and air-conditioning apparatus using a non-azeotropic mixed refrigerant according to a sixth embodiment of the present invention.

FIG. 18 is a configuration diagram showing a refrigerating and air-conditioning apparatus using a non-azeotropic mixed refrigerant according to Example 7 of the present invention.

FIG. 19 is a control block diagram of a refrigerating and air-conditioning apparatus using a non-azeotropic mixed refrigerant according to a seventh embodiment of the present invention.

FIG. 20 is a configuration diagram showing a refrigerating and air-conditioning apparatus using a non-azeotropic mixed refrigerant according to an eighth embodiment of the present invention.

FIG. 21 is a control block diagram of a refrigerating and air-conditioning apparatus using a non-azeotropic mixed refrigerant according to Example 8 of the present invention.

FIG. 22 is a configuration diagram showing a conventional refrigerating and air-conditioning apparatus using a non-azeotropic mixed refrigerant.

[Explanation of symbols]

1 Compressor 2 Condenser 3 Electric Expansion Valve 4 Evaporator 5 Accumulator 11 Temperature Detector 12 Pressure Detector 13 Temperature Detector 14 Pressure Detector 15 Liquid Level Detector 16 Temperature Detector 20 Composition Calculator 21 Controller 22 Comparison Calculator 23 Alarm device 31 Four-way valve 32 Outdoor heat exchanger 41 Indoor heat exchanger 42 Temperature detector 43 Temperature detector 50 Bypass piping 51 Second expansion valve 52 Heat exchange section

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tomohiko Kasai 6-5-66 Tehira, Wakayama City Mitsubishi Electric Corporation Wakayama Factory

Claims (8)

[Claims] 1. A refrigerating cycle comprising a compressor, a condenser, an expansion valve, and an evaporator connected by using a non-azeotropic mixed refrigerant as the refrigerant, wherein the refrigerant temperature at the inlet of the evaporator is detected. 1 temperature detector, a pressure detector for detecting the refrigerant pressure at the evaporator inlet, a second temperature detector for detecting the refrigerant temperature at the condenser outlet, a first temperature detector, the pressure detector, and a second temperature A composition calculator for calculating the refrigerant composition circulating in the cycle from the signal detected by the detector, and a controller for controlling the operation of the refrigeration cycle according to the refrigerant composition detected by the composition calculator A refrigerating and air-conditioning system using a non-azeotropic mixed refrigerant. 2. A temperature for detecting a refrigerant temperature at an inlet of an evaporator in a refrigerating cycle in which a non-azeotropic mixed refrigerant is used as a refrigerant and a compressor, a condenser, an expansion valve and an evaporator are connected to each other. Detector, a pressure detector for detecting the refrigerant pressure at the evaporator inlet, a composition calculator for calculating the refrigerant composition circulating in the cycle from the signals detected by the temperature detector and the pressure detector, and this composition A refrigerating and air-conditioning apparatus using a non-azeotropic mixed refrigerant, comprising a control device that controls the operation of the refrigeration cycle according to the refrigerant composition detected by a computing unit. 3. A refrigeration cycle comprising a compressor, a condenser, an expansion valve, an evaporator, and an accumulator connected to each other by using a non-azeotropic mixed refrigerant as a refrigerant, in the accumulator or in the accumulator and the compressor. A temperature detector for detecting the refrigerant temperature between the suction pipe, the accumulator, or a pressure detector for detecting the refrigerant pressure between the accumulator and the compressor suction pipe, the temperature detector and the pressure detector. From the detected signal, a composition calculator for calculating the refrigerant composition circulating in the cycle, and a control device for controlling the operation of the refrigeration cycle according to the refrigerant composition detected by the composition calculator, Refrigerating and air-conditioning system using non-azeotropic mixed refrigerant. 4. A liquid for detecting a liquid level of the accumulator, wherein a refrigeration cycle is formed by connecting a compressor, a condenser, an expansion valve, an evaporator and an accumulator using a non-azeotropic mixed refrigerant as the refrigerant. Surface detection means, from the signal detected by the liquid level detection means, a composition calculator for calculating the refrigerant composition circulating in the cycle, and operation control of the refrigeration cycle according to the refrigerant composition detected by the composition calculator A refrigerating and air-conditioning apparatus using a non-azeotropic mixed refrigerant, characterized in that it is provided with a control device. 5. A refrigeration cycle comprising a non-azeotropic mixed refrigerant as a refrigerant, which is connected to a compressor, a four-way valve, a first heat exchanger, a first expansion valve, and a second heat exchanger,
A bypass pipe that connects the pipe between the first heat exchanger and the first expansion valve and the suction pipe of the compressor via the second expansion valve; and a first pipe that detects the refrigerant temperature at the outlet of the second expansion valve. 1 temperature detector, pressure detector that detects the refrigerant pressure at the outlet of the second expansion valve, second that detects the refrigerant temperature at the inlet of the second expansion valve
A composition calculator that calculates the refrigerant composition circulating in the cycle from the signals detected by the temperature detector, the first temperature detector, the pressure detector, and the second temperature detector, and the refrigerant detected by the composition calculator A refrigerating and air-conditioning apparatus using a non-azeotropic mixed refrigerant, comprising a control device that controls the operation of the refrigeration cycle according to the composition. 6. A refrigeration cycle in which a non-azeotropic mixed refrigerant is used as a refrigerant, and a compressor, a four-way valve, a first heat exchanger, a first expansion valve, and a second heat exchanger are connected to each other to constitute a refrigeration cycle,
Bypass pipe connecting the pipe between the first heat exchanger and the first expansion valve and the suction pipe of the compressor via the second expansion valve, the temperature for detecting the refrigerant temperature at the outlet of the second expansion valve A detector, a pressure detector that detects the refrigerant pressure at the outlet of the second expansion valve, a composition calculator that calculates the refrigerant composition circulating in the cycle from the signals detected by the temperature detector and the pressure detector, and A refrigerating air-conditioning apparatus using a non-azeotropic mixed refrigerant, comprising a control device for controlling the operation of the refrigeration cycle according to the refrigerant composition detected by the composition calculator. 7. The non-azeotropic method according to claim 5, wherein the bypass pipe is provided with a heat exchange section for exchanging heat with the pipe between the first heat exchanger and the first expansion valve. Refrigeration air conditioner using mixed refrigerant. 8. A comparison calculation means for issuing a warning signal when the refrigerant composition detected by the composition calculation device is out of a predetermined range, and an alarm means for operating according to an alarm signal issued by the comparison calculation means. A refrigerating and air-conditioning apparatus using the non-azeotropic mixed refrigerant according to any one of claims 1 to 7.