JPH0868567A - Low-temperature generator - Google Patents

Abstract

PURPOSE: To use refrigerant which can clear the regulation based on fluorocarbon and to generate the deep freezing low temperature of a predetermined temperature zone by one compressor by using specific mixed refrigerant as non-azeotropic refrigerant, and setting the temperature range of the generated low temperature to a predetermined value. CONSTITUTION: A low-temperature generator using non-azeotropic refrigerant comprises a non-azeotropic refrigerant compressor 10, a condenser 12 of compressed refrigerant, a gas-liquid separator 30 for separating to liquid phase and gas phase, a liquid phase refrigerant first expansion valve 32, a cascade cooler 16 for cooling to liquefy the gas-phase refrigerant, a gas-phase refrigerant second expansion valve 34, and an evaporator 2 for generating low temperature. The gas-phase refrigerant from the evaporator 22 is supplied together with the liquid-phase refrigerant from the valve 32 to the cooler 16, and returned to the suction side of the compressor 10. In such a low-temperature generator, mixed refrigerant of R-134a and R-23 is used as the man-azeotropic refrigerant, and the temperature range of the generated low temperature is -30 deg.C to -70 deg.C.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a low-temperature generator, and more particularly to a low-temperature generator that uses a non-azeotropic mixed refrigerant to generate deep-chilled low temperature with a single compressor.

[0002]

2. Description of the Related Art The production of a low temperature of 0 ° C. or lower has a wide range of fields of use such as freeze-drying and freeze-drying, chemical and chemical manufacturing processes.

Conventionally, low temperature production up to about -25 ° C. has been performed by an ordinary single-stage refrigeration compression cycle. Further, a two-stage compression refrigeration cycle and a dual refrigeration cycle have been used for generation of low temperatures lower than that.

FIG. 2 shows an example of a conventional binary refrigeration cycle. This dual refrigeration cycle is composed of a high temperature side refrigeration cycle and a low temperature side cold temperature cycle. The high temperature side refrigeration cycle is composed of a compressor 10, a condenser 12, an expansion valve 14 and a cascade cooler 16, and is filled with a high-boiling single-component refrigerant. The low temperature side refrigeration cycle includes a compressor 18, a cascade cooler 16, an expansion valve 20.
And an evaporator 22, and is filled with a low-boiling single-component refrigerant.

In the high temperature side refrigeration cycle, the high boiling point refrigerant is liquefied by being compressed by the compressor 10 and cooled by the condenser 12. After that, the high-boiling-point refrigerant that has been liquefied by cooling is expanded by the expansion valve 14 to lower its temperature and supplied to the cascade cooler. The high boiling point refrigerant discharged from the cascade cooler is sucked into the compressor again to form a high temperature side refrigeration cycle.

On the other hand, in the low temperature side refrigeration cycle, the low boiling point refrigerant is compressed by the compressor 18, and is cooled in the cascade cooler 16 using the high boiling point refrigerant supplied from the high temperature side refrigeration cycle to be liquefied. After that, the low boiling point refrigerant is expanded by the expansion valve 20 to reduce its temperature and supplied to the evaporator to exchange heat with the object to be cooled and generate a desired low temperature. The low boiling point refrigerant discharged from the evaporator is sucked into the compressor 18 and forms a low temperature side refrigeration cycle.

Therefore, the high temperature side refrigeration cycle and the low temperature side refrigeration cycle are thermally coupled by the cascade cooler 16, and the low temperature boiling point refrigerant is condensed using the heat of vaporization of the high boiling point refrigerant.

Conventionally, a method of combining two refrigerating cycles as described above has been carried out in order to generate a deep cold temperature of -30 ° C or lower.

[0009]

However, in the above-mentioned conventional low temperature generation method, since a compressor is required for each of the high temperature side refrigeration cycle and the low temperature side refrigeration cycle, there is a problem that the apparatus becomes complicated and expensive. It was

To solve this problem, it is possible to appropriately select the refrigerant used in the single-stage compression refrigeration cycle and lower the low temperature temperature range that can be generated. For example, the refrigerant R-50
When 2 was used, a low temperature up to about -40 ° C could be generated in a single-stage compression cycle.

However, R-502 is a specific CFC R
Since it is an azeotropic refrigerant containing -115, its use is 1
It will be impossible by the end of 995. Therefore, there is a problem that only a refrigerant that clears the CFC refrigerant or HCFC refrigerant regulation, so-called CFC regulation, can be used in the future.

The present invention has been made in view of the above-mentioned conventional problems, and an object thereof is to use a refrigerant capable of clearing the CFC regulation and to reduce the temperature from -30 ° C by a single compressor without requiring an expensive device. An object of the present invention is to provide a low temperature generator capable of generating deep cold low temperature in the temperature range of −70 ° C.

[0013]

In order to achieve the above object, the invention described in claim 1 of the present application is a low-temperature generator using a non-azeotropic mixed refrigerant, wherein the non-azeotropic mixed refrigerant is compressed. A compressor, a condenser for partially condensing the refrigerant compressed by the compressor, the partially condensed refrigerant, a liquid phase rich in high-boiling components and a gas phase rich in low-boiling components To the gas-liquid separator, the first expansion valve for expanding the separated liquid-phase refrigerant, and the liquid-phase refrigerant expanded by the first expansion valve are supplied, whereby the separated gas-phase refrigerant A cascade cooler for cooling and liquefying the refrigerant, a second expansion valve for expanding the cooled and liquefied vapor phase refrigerant, and a vapor phase refrigerant expanded by the second expansion valve to thereby generate an evaporator at a low temperature And a gas phase discharged from the evaporator, including Medium is supplied to the cascade cooler together with the liquid-phase refrigerant flowing out from the first expansion valve, characterized in that the return to the suction side of the compressor from the cascade cooler.

According to a second aspect of the present invention, a low temperature generator using the non-azeotropic mixed refrigerant according to the first aspect includes a charge modulator connected to the gas-liquid separator, and the gas-liquid separator is in operation. Part of the liquid-phase refrigerant generated in the separator is isolated in the charge modulator, and the composition of the non-azeotropic mixed refrigerant in the chamber can be adjusted.

According to a third aspect of the present invention, a low-temperature generator using the non-azeotropic mixed refrigerant according to the first aspect measures the refrigerant temperature at either the inlet or the outlet of the evaporator. A condenser means for increasing or decreasing the amount of heat removed by the condenser, the condenser cooling accessory adjusting the amount of heat removed by the condenser on the basis of a signal from the temperature measuring means, It is characterized by controlling the degree of partial condensation in the vessel.

According to a fourth aspect of the present invention, a low temperature generator using the non-azeotropic mixed refrigerant according to the first aspect is provided for detecting a refrigerant temperature at either the inlet or the outlet of the evaporator. A temperature control means and a capacity control means for increasing / decreasing a compression capacity of the compressor, wherein the capacity control means adjusts a refrigerant circulation amount based on a signal from the temperature measurement means to follow a load change. To do.

According to a fifth aspect of the present invention, a low temperature generator using the non-azeotropic mixed refrigerant according to the first aspect of the invention measures the temperature of the refrigerant at either the inlet or the outlet of the evaporator. A temperature means, a condenser cooling auxiliary machine for increasing or decreasing the amount of heat removed by the condenser, and a capacity control means for increasing or decreasing the compression capacity of the compressor, based on a signal from the temperature measuring means,
The condenser cooling auxiliary device and the capacity control means operate either sequentially or in parallel to perform temperature control of the evaporator and follow load changes.

[0018]

According to the above construction, after the non-azeotropic mixed refrigerant is compressed and partially condensed, it is separated by the gas-liquid separator into a liquid phase rich in high-boiling components and a gas phase rich in low-boiling components. Since each is used for the high temperature side refrigeration cycle and the low temperature side refrigeration cycle, a single compressor can realize a combination of two stages of refrigeration cycles.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the structure of a low temperature generator according to the present invention. The same members as those in the conventional example shown in FIG.

The refrigerant used in the low temperature generator of the present embodiment is a non-azeotropic mixed refrigerant, which is a mixture of two kinds of refrigerants having no azeotropic property. Examples of these refrigerants include R-134a (single boiling point minus 26.
It is possible to use a mixture of 2 ° C.) and R-23 (single boiling point minus 82.1 ° C.). All of these refrigerants are refrigerants that can meet the above-mentioned CFC regulations.

When this non-azeotropic mixed refrigerant is heated and boiled under a constant pressure, or conversely cooled and condensed, a vapor phase and a liquid phase which are in equilibrium and have different compositions are generated. The gas phase contains a large amount of low-boiling components such as R-23, and the liquid phase contains a large amount of high-boiling components such as R-134a. These are based on the vapor-liquid equilibrium of the two components, but the larger the boiling point difference between the two components, the greater the degree of separation of the two components, that is, the concentration of the low-boiling component contained in the gas phase and the liquid phase The concentration of the high boiling point component is increased. In this example, the concentrations of the low-boiling component and the high-boiling component separated into the gas phase and the liquid phase should be as high as possible. Therefore, the combination of R134a and R-23 described above is also suitable from this point. is there.

Next, the operation of the low temperature generator shown in FIG. 1 will be described.

The non-azeotropic mixed refrigerant is compressed by the compressor 10 and partially condensed by the condenser 12, and then the gas-liquid separator 3 is used.
0 is supplied. In the condenser 12, since the non-azeotropic mixed refrigerant is partially condensed, there are a gas phase and a liquid phase, and as described above, the gas phase is rich in low-boiling components and the liquid phase is high. The composition is rich in boiling point components. This is separated into a gas phase and a liquid phase by the gas-liquid separator 30.

The liquid-phase refrigerant separated by the gas-liquid separator 30 (hereinafter referred to as high-boiling mixed refrigerant) is expanded by the first expansion valve 32 and its temperature is lowered. The high boiling point mixed refrigerant expanded by the first expansion valve 32 and lowered in temperature is supplied to the cascade cooler 16.

On the other hand, the gas-phase refrigerant separated by the gas-liquid separator 30 (hereinafter referred to as the low boiling point mixed refrigerant) passes through the cascade cooler 16, at which time the high boiling point mixed refrigerant described above is used in the cascade cooler 16. It is heat-exchanged, cooled, and liquefied.

Therefore, the refrigerant separated into the liquid phase and the gas phase by the gas-liquid separator 30 is supplied to the cascade cooler 16 in the state of being separated into the high boiling point mixed refrigerant and the low boiling point mixed refrigerant, respectively. As a result, the cascade cooler 16 operates as shown in FIG.
As in the case of the conventional dual refrigeration cycle shown in FIG. 3, the high temperature side refrigeration cycle and the low temperature side refrigeration cycle are thermally coupled.

The low boiling point mixed refrigerant liquefied by the cascade cooler 16 is expanded by the second expansion valve 34 and its temperature is lowered. The low boiling point mixed refrigerant whose temperature has been lowered by the second expansion valve 34 is supplied to the evaporator 22, and heat is exchanged with the object to be cooled in this evaporator 22 to generate a desired low temperature. Here, since the composition of the low boiling point mixed refrigerant supplied to the evaporator 22 is rich in the low boiling point component, the evaporator 22 can generate a low temperature close to the evaporation temperature of the low boiling point component alone.

For example, the above-mentioned R-134a and R-23
According to the combination with, the temperature range of the low temperature to be generated is deep cold low temperature of −30 ° C. to −70 ° C.

The low-boiling-point mixed refrigerant that has produced the deep-chilled low temperature in the evaporator 22 is discharged from the evaporator 22, and then the first expansion valve 3
It joins with the above-mentioned high-boiling-point mixed refrigerant coming out of 2, and is supplied to the cascade cooler 16 together. Therefore, the evaporator 2
The low boiling point mixed refrigerant discharged from 2 is also the cascade cooler 1
In 6, the low boiling point mixed refrigerant is used as a part of the refrigerant for liquefying. Further, since the low boiling point mixed refrigerant discharged from the evaporator 22 is mixed with the high boiling point mixed refrigerant from the first expansion valve 32, the same as the mixed refrigerant before being separated by the gas-liquid separator 30 after this. It returns to the composition and returns to the compressor 10 via the cascade cooler 16. As described above, the refrigeration cycle of this embodiment is formed.

Next, a method of controlling the low temperature generator of this embodiment will be described.

FIG. 3 shows the phase change characteristics of the mixture of R-134a and R-23 under a constant pressure. In FIG. 3, the vertical axis represents the temperature, and the horizontal axis represents the composition concentration, that is, the molar fraction ξ of R-23 in the mixture. The curve V shown in FIG. 3 is a vapor phase line, and the region above this line in the figure shows the vapor phase region. That is, in the region above the vapor phase line V, only the vapor phase always exists regardless of the mole fraction of R-23. The curve L is the liquid phase line, and the region below this line in the figure shows the liquid phase region. That is, the liquidus line L
In the lower region, only the liquid phase is always present regardless of the mole fraction of R-23. And the area between both curves V and L is
A gas-liquid mixed phase is shown, and a gas phase and a liquid phase are mixed in this region, and these are usually in a gas-liquid equilibrium state.

As shown in FIG. 3, in the process of condensing the mixed refrigerant having a certain composition concentration ξ ₁ compressed by the compressor 10 in the condenser 12, it depends on the extent to which partial concentration is limited. The concentration of low boiling point components in the gas phase changes. That is, when the mixed refrigerant having a certain compositional concentration ξ ₁ is cooled, it eventually reaches a point a on the vapor phase line V, and when the temperature is further lowered, a liquid phase appears and becomes a gas-liquid mixed phase. Further, when cooled to the point b, the mixed refrigerant has a composition at the intersections v ₁ and l ₁ of the isotherm drawn equilibrium on the horizontal axis (concentration axis) at the point b and the vapor phase line V and the liquid phase line L. A gas-liquid equilibrium is reached by separating into a gas phase and a liquid phase having a concentration. When this is further cooled and reaches point c, the composition concentrations of the vapor phase and the liquid phase reaching vapor-liquid equilibrium become the composition concentrations corresponding to v ₂ and l ₂ , respectively. Both points b and c represent the degree of condensation when the mixed refrigerant compressed by the compressor 10 is partially condensed by the condenser 12. As described above, it can be seen that the concentration of R-23 contained in the gas phase and the liquid phase, that is, the composition concentration changes depending on the degree of partial condensation.

Therefore, by controlling the degree of partial condensation, it is possible to control the concentration of the low boiling point component of the gas-phase refrigerant separated in the gas-liquid separator 30, and thus the low boiling point obtained through the second expansion valve 34. The boiling point of the boiling point mixed refrigerant can be controlled.

Therefore, by controlling the condenser cooling auxiliary equipment such as a cooling water system or a cooling air system pump, fan, damper, etc., which is the cooling medium of the condenser 12, the amount of heat removed in the condenser 12 can be controlled. The cryogenic temperature of the evaporator 22 can be controlled. The control of the condenser cooling auxiliary equipment detects the boiling point temperature of the refrigerant in the evaporator 22 by a side temperature means (not shown) at the inlet or outlet of the low boiling point mixed refrigerant in the evaporator 22, and based on this boiling point temperature. It may be performed by PID control or the like.

The low temperature range obtained by the evaporator 22 is the range of the evaporation temperature of the low boiling point mixed refrigerant supplied to the evaporator 22. For example, in the case of the refrigerant partially condensed to the point c shown in FIG. 3 in the condenser 12, it is in the range of the evaporation temperature of the low boiling point mixed refrigerant on the gas phase side, that is, the range of t _w1 . Therefore, in the case of a mixed refrigerant of composition concentration ξ ₁ ,
The lower limit of the low temperature at which the range t _w2 of the evaporation temperature of the refrigerant having the compositional concentration corresponding to the point d on the liquid phase line L and the point v ₃ on the gas phase line in gas-liquid equilibrium is obtained.

Therefore, when a vaporization temperature higher or lower than this is required, the degree of partial condensation in the condenser 12 is changed, or the composition concentration ξ of the mixed refrigerant sealed in the low temperature generator of this embodiment is ξ. Must be set to ξ ₂ or ξ ₃ in advance.

The composition concentration of the mixed refrigerant to be enclosed is ξ
In the adjustment of, the high boiling point component and the low boiling point component may be first enclosed in a predetermined ratio, or, as shown in FIG.
A charge modulator 36 is connected to the gas-liquid separator 30, and a part of the liquid phase generated in the gas-liquid separator 30 during the operation of the low-temperature generator is isolated by the charge modulator 36 to form an enclosed composition. It may be adjusted.

On the other hand, when the load fluctuates during operation at a certain evaporation temperature, the load fluctuation is tracked as follows.

As described above, the evaporation temperature of the refrigerant in the evaporator 22 can be controlled by the degree of partial condensation in the condenser 12. In this case, when the load fluctuates and the boiling point temperature of the vapor-phase refrigerant in the evaporator 22 changes, the condenser 12 operates as follows in an attempt to correct this temperature deviation. That is, when the load increases and the boiling temperature rises, the condensing temperature is also lowered in an attempt to lower it, and the degree of partial condensation in the condenser 12 is raised.

In general, the vapor-liquid molar ratio when the mixed refrigerant is partially condensed in the evaporator 12 is represented by the ratio of the distance between the point representing the degree of partial condensation and the liquidus line or the vapor phase line. . That is, in the point b of FIG. 3, the ratio of the distance b-l ₁ and b-v ₁ of the distance represents the molar ratio between the gas phase and the liquid phase. Therefore, the molar amount of the gas phase is smaller at the point c than at the point b. When further cooled to the point d, the gas phase does not exist.

From the above, when the condensation temperature in the condenser 12 is lowered, the amount of the low boiling point mixed refrigerant separated in the gas-liquid separator 30 decreases. As a result, the amount of the low boiling point mixed refrigerant supplied to the evaporator 22 via the second expansion valve 34 also decreases.

On the other hand, when the load is reduced and the boiling temperature in the evaporator 22 is lowered, the condenser 12 raises the condensation temperature in order to raise this temperature. As a result, contrary to the above case, the amount of the low boiling point mixed refrigerant separated by the gas-liquid separator 30 increases, and the amount of the low boiling point mixed refrigerant supplied to the evaporator 22 also increases.

As a result of the above, when the temperature of the evaporator 22 is to be lowered, the amount of the low boiling point mixed refrigerant supplied to the evaporator 22 is reduced, and when it is desired to raise the temperature of the evaporator 22, it is supplied to the evaporator 22. The amount of the low boiling point mixed refrigerant increases. This is a reverse operation as the control operation of the evaporator 22.

Therefore, when the degree of partial condensation in the condenser 12 is changed according to the temperature deviation of the evaporator 22, it is necessary to change the circulation amount of the refrigerant in conjunction with this. That is, when the boiling point temperature in the evaporator 22 rises due to the increase in the load, it is necessary to increase the capacity of the compressor 10 in order to increase the amount of the low boiling point mixed refrigerant supplied to the evaporator 22. If the boiling point temperature in the evaporator 22 decreases due to the decrease of the
It is necessary to reduce the capacity of the compressor 10 in order to reduce the amount of the low boiling point mixed refrigerant supplied to the compressor.

This is because the compressor 10 is provided with a capacity control means (not shown), and based on a signal from the side temperature means provided at the inlet or outlet of the vapor phase refrigerant of the evaporator 22, the capacity control means is controlled. You can control it.

The capacity control means is achieved by controlling the suction amount of the compressor or by making the compressor rotational speed variable.

As described above, the degree of partial condensation of the condenser 12 is adjusted by the condenser cooling auxiliary machine, or the capacity of the compressor 10 is controlled by the capacity control means to operate these independently or in conjunction with each other. By doing so, it is possible to control the temperature of the evaporator 22 and follow the load fluctuation.

[0049]

As described above, according to the present invention,
After compressing and partially condensing the non-azeotropic mixed refrigerant, the gas-liquid separator separates it into a liquid phase rich in high-boiling components and a gas phase rich in low-boiling components. Since it is used for the side refrigeration cycle, a single compressor can realize a combination of two stages of refrigeration cycles. Further, the refrigerant used at that time can be one that can clear the CFC regulation, such as a mixture of R-134a and R-23.

As a result, it is possible to use a refrigerant capable of clearing the CFC regulation, and a low-temperature generator capable of producing deep-cooled low temperature in the temperature range of -30 ° C to -70 ° C by one compressor without requiring an expensive device. Can be provided.

Further, R-134 used as a refrigerant
When the mixture of a and R-23 is sucked into the compressor, the temperature becomes close to room temperature, so the mechanical reliability of each part of the compressor is improved. In addition, since the lubricating oil of the compressor entrained in the refrigerant circulates in the high temperature side refrigeration cycle, the oil is reliably returned to the compressor, and the lubricating trouble of the compressor is reduced.
Further, since the lubricating oil does not circulate in the low temperature side refrigeration cycle, heat transfer in the evaporator is less likely to be hindered.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a low temperature generator according to the present invention.

FIG. 2 is a block diagram showing a configuration of a conventional low temperature generation device using a dual refrigeration cycle.

FIG. 3 is a diagram showing a phase change characteristic of a mixed refrigerant of R-134a and R-23 under a constant pressure.

[Explanation of Codes] 10, 18 Compressor 12 Condenser 14, 20, 32, 34 Expansion valve 16 Cascade cooler 22 Evaporator 30 Gas-liquid separator 36 Charge modulator

[Procedure amendment]

[Submission date] September 26, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Claims

[Correction method] Change

[Correction content]

[Claims]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0021

[Correction method] Change

[Correction content]

The refrigerant used in the low temperature generator of the present embodiment is a non-azeotropic mixed refrigerant, which is a mixture of two kinds of refrigerants having no azeotropic property. As these refrigerants , a mixture of R- 134a (single boiling point minus 26.2 ° C) and R-23 (single boiling point minus 82.1 ° C) can be used. All of these refrigerants are refrigerants that can meet the above-mentioned CFC regulations.

[Procedure 3]

[Document name to be amended] Statement

[Name of item to be corrected] 0029

[Correction method] Change

[Correction content]

According to the combination of R-134a and R-23 was above mentioned, the low temperature of the temperature range to be generated consists of minus 30 ° C. and cryogenic cold minus 70 ° C..

Claims (5)

[Claims] 1. A low temperature generator using a non-azeotropic mixed refrigerant, comprising: a compressor for compressing the non-azeotropic mixed refrigerant; and a condenser for partially condensing the refrigerant compressed by the compressor. A gas-liquid separator for separating the partially condensed refrigerant into a liquid phase rich in a high boiling point component and a gas phase rich in a low boiling point component, and a first expansion valve for expanding the separated liquid phase refrigerant And the liquid-phase refrigerant expanded by the first expansion valve is supplied,
Thereby, a cascade cooler for cooling and liquefying the separated gas-phase refrigerant, a second expansion valve for expanding the cooling-liquefied gas-phase refrigerant, and a gas-phase refrigerant expanded by the second expansion valve are supplied. ,
The vapor-phase refrigerant discharged from the evaporator is supplied to the cascade cooler together with the liquid-phase refrigerant discharged from the first expansion valve. A low-temperature generator using a non-azeotropic mixed refrigerant, which returns to the suction side of the compressor. 2. The low temperature generator using the non-azeotropic mixed refrigerant according to claim 1, comprising a charge modulator connected to the gas-liquid separator, and the liquid phase generated in the gas-liquid separator during operation. A low temperature generator using a non-azeotropic mixed refrigerant, characterized in that a part of the refrigerant is isolated to the charge modulator, and the composition of the non-azeotropic mixed refrigerant in the chamber can be adjusted. 3. A low temperature generator using the non-azeotropic mixed refrigerant according to claim 1, wherein a temperature measuring means for detecting a refrigerant temperature at either an inlet or an outlet of the evaporator, and a condenser of the condenser. A condenser cooling auxiliary device that increases or decreases the amount of heat removed, and the condenser cooling auxiliary device adjusts the amount of heat removed by the condenser based on a signal from the temperature measuring means to control the degree of partial condensation in the condenser. A low-temperature generation device using a non-azeotropic mixed refrigerant characterized by being controlled. 4. A low temperature generator using the non-azeotropic mixed refrigerant according to claim 1, wherein a temperature measuring means for detecting the refrigerant temperature at either the inlet or the outlet of the evaporator, and the compressor. A non-azeotropic mixed refrigerant characterized by including a capacity control means for increasing or decreasing a compression capacity, wherein the capacity control means adjusts a refrigerant circulation amount based on a signal from the temperature measuring means to follow a load change. Low temperature generator. 5. A low temperature generator using the non-azeotropic mixed refrigerant according to claim 1, wherein a temperature measuring means for detecting a refrigerant temperature at either an inlet or an outlet of the evaporator, and a condenser of the condenser. A condenser cooling auxiliary device for increasing / decreasing the amount of heat removed, and a capacity control means for increasing / decreasing the compression capacity of the compressor, and based on a signal from the temperature measuring means, the condenser cooling auxiliary equipment and the capacity control means. Is operated either sequentially or in parallel to perform temperature control of the evaporator and follow load fluctuations, and a low temperature generator using a non-azeotropic mixed refrigerant.