KR100492169B1 - R502 and r22 substitute mixed refrigerant and refrigeration system using thereof - Google Patents

Abstract

The present invention relates to a mixed refrigerant for replacing R502 and R22 used in a vapor compression refrigerator or an air conditioner and a refrigeration system using the same, and more particularly, to replace an existing refrigeration system without causing ozone layer destruction and global warming. The present invention relates to a mixed refrigerant composed by selectively combining propylene, propane, and 1,1,1,2-tetrafluoroethane, and a refrigeration system using the same. The mixed refrigerant according to the preferred embodiment of the present invention is 1 to 99 parts by weight of R1270 (propylene), 98 parts by weight or less of R290 (propane), and 1 to 70 parts by weight of R134a (1,1,1,2-tetrafluoroethane). It is composed.

Description

R502 AND R22 SUBSTITUTE MIXED REFRIGERANT AND REFRIGERATION SYSTEM USING THEREOF}

The present invention relates to a material that can be used as a refrigerant (referred to as R) in a vapor compression refrigeration / air conditioner, that is, a mixed refrigerant comprising a combination of propylene, propane, and R134a and a refrigeration system using the same. Specifically, R502 (hereinafter referred to as CFC502), which has been widely used in low temperature freezers and transport refrigerators, and monochlorofluoromethane (CHClF ₂ , R22 or HCFC22), which have been widely used in domestic air conditioners and commercial air conditioners. And a refrigeration system using the same.

CFC502 is an azeotropic mixed refrigerant comprising 48.8% monochlorofluoromethane (hereinafter referred to as R22 or HCFC22) and 51.2% chloropentafluoroethane (hereinafter referred to as R115 or CFC115).

To date, the refrigerants used in refrigerators, air conditioners, heat pumps, etc. have mainly been used chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) derived from methane or ethane. . In particular, CFC502 with boiling point of -45.4 ℃ and molecular mass of 111.6kg / kmol has been most widely used in low temperature freezers, transport freezers, supermarket freezers, etc., and has a boiling point of -40.8 ℃ and high molecular mass for home air conditioners and commercial air conditioners. HCFC22, 86.47 kg / kmol, has been the most widely used.

Recently, however, the destruction of the stratospheric ozone layer by CFCs and HCFCs has emerged as an important global environmental problem, and as a result the production and use of stratospheric ozone depleting CFCs and HCFCs is regulated by the Montreal Protocol adopted in 1987. The CFC502 and HCFC22 have high Ozone Depletion Potential (ODP) of 0.18 and 0.05, respectively, and are now expected to be fully or fully pursuant to the Montreal Protocol in developed countries. You are trying to use an alternative refrigerant with an ODP of 0.0.

In addition, in addition to the problem of ozone depletion, global warming has begun to emerge rapidly, and the 1997 Kyoto Protocol strongly recommends refraining from using HFC refrigerants with high global warming potential (GWP). . Reflecting this trend, European and Japanese refrigerator manufacturing companies use isobutane (hereinafter referred to as R600a) as a refrigerant in almost all refrigerators and produce household air conditioners, heat pumps, low temperature freezers and automobile air conditioners. Some are also trying to use hydrocarbon-based refrigerants with a low global warming index (GWP).

Table 1 shows the environmental indices of some refrigerants. As shown in Table 1, propylene, propane, isobutane, DME, and HFC152a have an ozone depletion index (ODP) of 0.0 and a global warming index (GWP). This is why most countries in the European Union, Japan and Asia now have a mixture of refrigerants with an ODP of 0.0 and lower GWP than conventional CFC or HFC refrigerants to achieve the desired thermodynamic properties while improving efficiency and compatibility with oil. Attempts have been made to increase. In this sense, propylene, propane, isobutane, DME, and HFC152a are eligible.

Refrigerant Ozone Depletion Index (ODP) Global Warming Index (GWP) CFC12 0.9 8,500 HFC134a 0.0 1,300 HCFC22 0.05 1,700 R407C 0.0 1,370 CFC502 0.18 4,510 R404A 0.0 3,850 HFC125 0.0 3,200 HFC143a 0.0 4,400 HFC152a 0.0 140 Propylene (R1270) 0.0 3 or less Propane (R290) 0.0 3 or less DME (RE170) 0.0 3 or less Isobutane (R600a) 0.0 3 or less

(*) ODP is based on CFC11 as 1.0.

(**) GWP is based on a 100-year carbon dioxide standard of 1.0.

In order for a material to be useful as an alternative to a conventional refrigerant, it must first have a coefficient of performance (COP) similar to that of a conventional refrigerant. The coefficient of performance (COP) refers to the total refrigeration effect compared to the work applied to the compressor, the larger the COP, the better the energy efficiency of the refrigeration / air conditioner. In addition, in order to use the compressor without major modifications, the alternative refrigerant must have a vapor pressure similar to that of the existing refrigerant and ultimately provide a similar volumetric capacity (VC). Here, the volumetric capacity (VC) refers to the refrigeration effect per unit volume, which is a factor indicating the size of the compressor, which is usually proportional to the vapor pressure and is in kJ / m 3. If the replacement refrigerant has a volume capacity similar to that of the existing refrigerant, it is very advantageous for manufacturers to build refrigeration / air conditioning without changing compressors or making major modifications. However, until now, studies have shown that in case of replacing the existing refrigerant with pure material, the volumetric capacity of the replacement refrigerant is different from that of the existing refrigerant, so it is inevitable that the compressor must be replaced or greatly modified, and it is difficult to obtain a similar coefficient of performance as the existing refrigerant. It turned out.

One way to solve this is to use a mixed refrigerant. The characteristic of a mixed refrigerant is that it can be formulated properly to give a coefficient of performance similar to that of a conventional refrigerant, while at the same time giving a volumetric capacity (VC) similar to that of a conventional refrigerant, thereby eliminating the need for major modifications to the compressor. Due to these characteristics, several mixed refrigerants have been proposed as substitutes for CFC502 and HCFC22 in the past few years, but some of them have HCFCs which are prohibited from use in the Montreal Protocol. .

Dupont of the United States has developed a three-way mixed refrigerant (44% R125 / 52% R143a / 4% R134a) called R404A that does not cause ozone decay, but this refrigerant is less energy efficient than R502, which may indirectly accelerate global warming. In addition, it is not a suitable substitute in the long term because it consists only of HFCs that restrict its use in the Kyoto Protocol. In addition, the three-way mixed refrigerant R407C (23% R32 / 25% R125 / 52% R134a), developed by DuPont, USA, has a freezing capacity similar to that of the existing HCFC22, but has low energy efficiency and a temperature gradient of about 7 ° C. If there is a leakage of the refrigerant in the refrigeration system has a disadvantage that the composition separation of the refrigerant occurs. In addition, if the temperature gradient becomes too large, the pressure in the evaporator and condenser is continuously changed due to the phase change of the refrigerant, which causes instability of the freezer system. Meanwhile, Allied Signal Co., Ltd. has developed and sold a binary mixture refrigerant (50% R32 / 50% R125) called R410A. However, the refrigerant pressure is about 60% higher than the conventional HCFC22. Since this is high, there is a problem that the strength of the material used in the condenser must be increased.

The present invention has been made to solve the above problems of the prior art, an object of the present invention is suitable for propylene, propane and 1,1,1,2-tetrafluoroethane, which are substances that do not cause ozone layer destruction and global warming. By using a combination of the composition ratio to provide a mixed refrigerant and a refrigeration system using the same that can be applied directly without replacing or greatly modifying the existing refrigeration system.

The purpose of the present invention described above is R1270 (propylene) 1 to 99 parts by weight, R290 (propane) 98 parts by weight or less, R134a (1,1,1,2-tetrafluoroethane) 1 It can be achieved by a mixed refrigerant consisting of to 70 parts by weight.

In order to achieve the above object, the mixed refrigerant is preferably composed of 1 to 30 parts by weight of R1270, 60 to 80 parts by weight of R290, and 1 to 10 parts by weight of R134a.

In addition, in order to achieve the above object, it is preferable that R1270 is 40 to 60 parts by weight, R290 is 40 to 60 parts by weight, and R134a is 1 to 10 parts by weight.

The above object of the present invention can also be achieved by a mixed refrigerant composed of 1 to 54 parts by weight of R1270 (propylene) and 46 to 99 parts by weight of R290 (propane) in the refrigerant mixture for refrigeration / air conditioning.

In addition, the above object of the present invention can be achieved by a mixed refrigerant consisting of 81 to 99 parts by weight of R1270 (propylene), 1 to 19 parts by weight of R290 (propane) in the refrigeration / air conditioning mixed refrigerant.

In addition, the object of the present invention described above is a mixed refrigerant consisting of 1 to 99 parts by weight of R1270 (propylene) and 1 to 70 parts by weight of R134a (1,1,1,2-tetrafluoroethane) in a refrigeration / air conditioner mixed refrigerant. Can also be achieved.

In order to achieve the above object, it is preferable that the mixed refrigerant for refrigeration / air conditioner is composed of 30 to 99 parts by weight of R1270 (propylene) and 1 to 70 parts by weight of R134a (1,1,1,2-tetrafluoroethane). .

In order to achieve the above object, in the refrigerant mixture for refrigeration / air conditioning, R1270 (propylene) 40 to 99 parts by weight, R134a (1,1,1,2-tetrafluoroethane) is preferably composed of 1 to 60 parts by weight. Do.

The above object of the present invention can also be achieved by a refrigerating / air conditioner using one of the above-listed mixed refrigerants.

Other objects, specific advantages and novel features of the invention will become more apparent from the following detailed description and the preferred embodiments associated with the accompanying drawings.

Hereinafter, with reference to the accompanying drawings it will be described in detail with respect to the configuration of the mixed refrigerant for R502 and R22 and the refrigeration system using the same according to an embodiment of the present invention.

The present invention relates to a material that can be used as a refrigerant (referred to as R) in a vapor compression refrigeration / air conditioner, that is, a 'combined refrigerant and a refrigeration system using a combination of propylene, propane, and R134a.' More specifically, R502 (hereinafter referred to as CFC502), which has been widely used in low temperature freezers and transport refrigerators, and monochlorofluoromethane (CHClF ₂ , R22 or HCFC22), which have been widely used in domestic air conditioners and commercial air conditioners. And a refrigeration system using the same.

The object of the present invention is that since the ODP is 0.0, it does not affect the ozone layer in the stratosphere at all, and the global warming index is also lower than that of other conventional refrigerants, and at the same time, it is an alternative refrigerant of CFC502 and HCFC22 without greatly modifying the existing compressor. It is to provide a mixed refrigerant that can be used and a refrigeration system using the same.

More specifically, the present invention relates to an alternative mixed refrigerant composed by selectively combining R1270 (propylene, propylene), R290 (propane, propane) and R134a (1,1,1,2 tetrafluoroethane). The alternative mixed refrigerant proposed in the present invention has an ozone depletion index (ODP) of 0.0 and a lower global warming index (GWP) than other alternative refrigerants, and the coefficient of performance (COP) and volume capacity (VC) of CFC502 or HCFC22. Yields a value close to

1 is a block diagram of a general refrigeration / air conditioner used in the present invention. As shown in FIG. 1, the refrigeration / air conditioner generally comprises an evaporator, a condenser, a compressor, an expansion valve, and the like.

To develop an alternative mixed refrigerant, the inventors used the CYCLE-D program developed by the National Institute of Standards and Technology, which simulates the performance of a refrigeration / air conditioner. The program conducted thermodynamic and heat transfer analyzes of the components that make up the refrigeration / air conditioner, such as heat exchangers and compressors, and finally used them all in combination. One of the important factors that determine the accuracy of the program is the properties of the refrigerant. In this program, the properties of all refrigerants were calculated using the Carnahan-Starling-De Santis (CSD) state equation, which is the standard in the United States and Japan. The CSD state equation, known as REFPROP, was developed by the National Institute of Standards and Technology and is the most widely used program in leading refrigeration and air conditioning companies, laboratories, and universities worldwide for its proven accuracy and applicability. The actual data was used as input data for the development and execution of the mixed refrigerant and refrigeration / air conditioner.

In the mixed refrigerant of the present invention, the ozone depletion index (ODP) of the alternative refrigerant for refrigeration / air conditioner must be 0.0 and the global warming index (GWP) should be as low as possible. , Propane) and R134a (1,1,1,2 tetrafluoroethane) were selectively mixed to replace the existing refrigerant.

[Table 2] shows the results of comparing the performance index of the mixed refrigerant according to the present invention with the performance index of the existing refrigerant calculated by the computerized analysis program by applying the conditions of the refrigeration / air conditioner using the existing CFC502 , [Table 3] shows the results of comparing the performance index of the mixed refrigerant according to the present invention with the performance index of the conventional refrigerant calculated by the computerized analysis program applying the conditions of use of the refrigeration / air conditioner using the existing HCFC22 will be.

[Performance Comparison of Examples of CFC502 and Mixed Refrigerants According to the Present Invention] Refrigerant Composition (% by weight) COP VC (kJ / ㎥) GTD (℃) Tdis (℃) COP _diff (%) VC _diff (%) R1270 R290 R134a CFC502 1.07 816 0.2 102.7 R404A 0.99 807 0.7 94.7 -7.5 -1.1 Inventive Example 1 10 90 1.17 767 0.4 102.2 9.3 -6.0 Inventive Example 2 30 70 1.20 841 0.6 103.9 12.1 3.1 Inventive Example 3 70 30 1.23 945 0.1 108.1 15.0 15.8 Inventive Example 4 30 70 1.27 794 6.3 109.9 18.7 -2.7 Inventive Example 5 50 50 1.27 914 1.3 109.4 18.7 12.0 Inventive Example 6 90 10 1.24 976 0.0 111.6 15.9 19.6 Inventive Example 7 10 80 10 1.21 829 2.0 101.5 13.1 1.6 Inventive Example 8 15 80 5 1.20 817 1.3 102.3 12.1 0.1 Inventive Example 9 30 60 10 1.23 897 1.2 103.3 15.0 9.9

[Performance Comparison of Examples of HCFC22 and Mixed Refrigerants According to the Present Invention] Refrigerant Composition (% by weight) COP VC (kJ / ㎥) GTD (℃) Tdis (℃) COP _diff (%) VC _diff (%) R1270 R290 R134a HCFC22 2.88 3565 0.0 98.2 R407C 2.79 3776 6.9 90.6 -3.1 5.9 Inventive Example 10 20 80 2.58 3200 0.6 81.5 -10.4 -10.2 Inventive Example 11 50 50 2.61 3464 0.3 82.9 -9.4 -2.8 Inventive Example 12 70 30 2.62 3575 0.1 83.9 -9.0 0.3 Inventive Example 13 90 10 2.62 3631 0.0 85.2 -9.0 1.9 Inventive Example 14 40 60 2.74 3597 3.5 84.3 -4.9 0.9 Inventive Example 15 60 40 2.69 3709 0.4 84.4 -6.6 4.0 Inventive Example 16 90 10 2.64 3674 0.0 85.4 -8.3 3.1 Inventive Example 17 40 50 10 2.64 3559 0.8 82.3 -8.3 -0.2 Inventive Example 18 50 40 10 2.64 3614 0.5 82.7 -8.3 1.4

COP: coefficient of performance (Coefficient of performance, total refrigeration effect / day applied to the compressor)

VC: Volumetric capacity

GTD: Grading temperature difference

T _dis : Compressor discharge temperature

COP _diff : Performance factor difference compared to CFC502 (Table 2) and HCFC22 (Table 3)

VC _diff : Volume difference between CFC502 (Table 2) and HCFC22 (Table 3)

Table 2 shows that the CFC502 replacement mixed refrigerants of Examples 1 to 9 of the present invention have higher or similar performance coefficients and similar volume capacities than conventional CFC502 or R404A.

[Table 3] shows that HCFC22 alternative mixed refrigerants have a slightly lower performance coefficient than HCFC22 or R407C, but have a similar volume capacity. In particular, HCFC22 alternative mixed refrigerants have a compressor discharge temperature of as much as 15 ℃ lower than HCFC22, and hydrocarbons are used as main shafts, so they are more compatible with oil, resulting in better performance than HCFC22 in actual refrigerators. In addition, the temperature gradients of the mixed refrigerants are all close to zero, except for one. Considering that the temperature gradient of the mixed refrigerant currently commercialized is usually less than 7 ℃, there is no problem in using these mixed refrigerants.

Since all the refrigerants of Examples 1 to 18 of the present invention have an ozone depletion index (ODP) of 0.0 and do not destroy the ozone layer at all, they are much superior to CFC502 and HCFC22 in terms of environmental preservation. In the case of R404A or R407C, which are alternatives to CFC502 and HCFC22, they are regulated under the Kyoto Protocol due to their high global warming index.

For reference, other compositions that deviate from the compositions of the present inventions described above, whether the temperature gradient is too large, the capacity and the efficiency are too low, or the compressor discharge temperature is too high, there is a problem in the actual application to the refrigeration / air conditioner, Look specifically.

[Inventive Examples 1, 2, 3]

As shown in Examples 1, 2, and 3 of the present invention, when R1270 is increased in the mixed refrigerant composed of R1270 and R290, the volumetric capacity of the mixed refrigerant increases and the compressor discharge temperature increases. It is preferable that the ratio of R1270 not exceed 55% by weight.

As shown in Table 2, the volumetric capacity of the mixed refrigerant of Inventive Example 2 in which R1270 constitutes 30% by weight was 841kJ / m3, but the volumetric capacity of the mixed refrigerant of Inventive Example 3 in which R1270 comprised 70% by weight was 945kJ. / M 3 was obtained. When R1270 is included in more than 70% by weight as described above, it becomes too large compared to the volumetric capacity of the existing refrigerant R404A 807kJ / ㎥, so the existing refrigeration system including the compressor must be replaced. Therefore, R1270 is preferably included at 55 wt% or less to have a volume capacity similar to that of the conventional refrigerant.

[Table 4] shows the performance of the mixed refrigerant and the existing refrigerant mixed with R1270 and R290 calculated using the computer analysis program under the refrigeration / air conditioner using the conventional CFC502. As shown in [Table 4], when R1270 exceeds 60% by weight, it can be seen that the volumetric capacity is significantly different from existing refrigerants R502 and R404A.

[Combined Refrigerant Performance of Various Compositions in Refrigeration / A / C with CFC502 Service Conditions] Refrigerant Composition (% by weight) COP VC (kJ / m ³ ) GTD (℃) Tdis (℃) COP _diff (%) VC _diff (%) R1270 R290 R134a R502 1.07 816 0.2 102.7 R404A 0.99 807 0.7 94.7 Comparative Example 1 10 90 0 1.17 766 0.4 102 - - Comparative Example 2 20 80 0 1.19 805 0.6 103 - - Comparative Example 3 30 70 0 1.20 841 0.6 104 - - Comparative Example 4 40 60 0 1.21 873 0.5 105 - - Comparative Example 5 50 50 0 1.22 901 0.4 106 - - Comparative Example 6 60 40 0 1.22 925 0.2 107 - - Comparative Example 7 70 30 0 1.23 945 0.1 108 - - Comparative Example 8 80 20 0 1.23 959 0.04 109 - - Comparative Example 9 90 10 0 1.23 969 0.01 111 - -

[Inventive Examples 4, 5, 6]

As shown in Examples 4, 5 and 6 of the present invention, when R1270 decreases and R134a increases in the mixed refrigerant composed of R1270 and R134a, the temperature gradient increases and the volume capacity decreases at the same time. In order to keep the temperature gradient as low as possible, it is preferable that the ratio of R1270 exceeds 30% by weight and the ratio of R134a does not exceed 70% by weight.

That is, when included in the ratio of 10% by weight, 50% by weight, 70% by weight the temperature gradient increased to 0.0 ℃, 1.3 ℃, 6.3 ℃. Therefore, the mixed refrigerant containing more than 70% by weight of R134a is not suitable because the temperature gradient becomes too large. If the temperature gradient of the mixed refrigerant is too large, the pressure of the evaporator and condenser will change due to the phase change of the mixed refrigerant, which may cause instability of the refrigeration system, and composition separation may occur when the refrigerant leaks from the refrigeration system. .

[Inventive Example 7, 8, 9, 17, 18]

Investigating Inventive Examples 7, 8, 9, 17 and 18 with reference to Inventive Examples 4, 5, 6, 14, 15 and 16, the temperature gradient was too large when R134a was 70% by weight or more in the mixed refrigerant. As the pressure in the evaporator and condenser is continuously changed due to the phase change of the refrigerant, it causes instability of the freezer system. Therefore, in the mixed refrigerant, R134a is preferably not more than 70% by weight.

[Invention example 7, 8, 9]

As shown in Examples 7, 8 and 9 of the present invention, when R1270 is 30% by weight or more in the mixed refrigerant, the volumetric capacity of the mixed refrigerant becomes too large and the condenser becomes a high pressure state so that the material of the condenser is replaced with a material of higher strength. It is not preferable to replace the compressor, and if R134a exceeds 10% by weight, the volume capacity becomes too small and at the same time the temperature gradient becomes too large, which is not preferable. In a state where R1270 and R134a occupy a relatively small ratio, it is preferable that R290 be in the range of 60 to 80 wt% in order for the mixed refrigerant to have a volume capacity similar to that of the existing refrigerant.

That is, according to the mixed refrigerants of Examples 7 and 9 of which R134a constitutes 10% by weight, when the composition of R1270 is increased from 10% by weight to 30% by weight, the volume capacity is increased from 829kJ / ㎥ to 897kJ / ㎥. Can be. Compared to the volume capacity of R404A, 807kJ / m3, the mixed refrigerant with R1270 ratio of more than 30% by weight is too large than the existing refrigerant R404A, so the existing refrigeration system cannot be used as it is. Therefore, the mixed refrigerant that can be directly applied without replacing the existing refrigeration system is required to be less than 30% by weight of the composition of R1270.

[Table 5] shows the performance indices of the mixed refrigerants mixed with R1270 and R134a and the performance indices of the conventional refrigerants, which were calculated using the computational analysis program under the conditions of the refrigeration / air conditioner using the conventional CFC502.

[Combined Refrigerant Performance of Various Compositions in Refrigeration / A / C with CFC502 Service Conditions] Refrigerant Composition (% by weight) COP VC (kJ / m ³ ) GTD (℃) Tdis (℃) COP _diff (%) VC _diff (%) R1270 R290 R134a R502 1.07 816 0.2 102.7 R404A 0.99 807 0.7 94.7 Comparative Example 11 10 0 90 1.22 556 6.9 109.6 - - Comparative Example 12 20 0 80 1.26 694 7.4 110 - - Comparative Example 13 30 0 70 1.27 795 6.1 110 - - Comparative Example 14 40 0 60 1.27 865 4.4 109.6 - - Comparative Example 15 50 0 50 1.26 914 2.7 109.3 - - Comparative Example 16 60 0 40 1.26 947 1.4 109.4 - - Comparative Example 17 70 0 30 1.25 968 0.6 109.9 - - Comparative Example 18 80 0 20 1.24 975 0.2 110.6 - - Comparative Example 19 90 0 10 1.24 976 0.04 111.6 - -

As shown in Table 5, in the mixed refrigerant consisting of R1270 and R134a, as the composition of R134a increases, the volumetric capacity decreases and the temperature gradient increases. In addition, the mixed refrigerant of Example 7 of the present invention, R134a constitutes 10% by weight, has a volume capacity of 829 kJ / m 3 and a temperature gradient of 2 ° C., and R404A has a volume capacity of 807 kJ / m 3 and a temperature gradient of 0.7. ℃. Therefore, in order to have a volumetric capacity and temperature gradient similar to that of R404A, it is preferable that the mixed refrigerant does not exceed 10% by weight of R134a.

[Inventive Examples 17 and 18]

As shown in Examples 17 and 18 of the present invention, when the ratio of R1270 in the mixed refrigerant is high, the volumetric capacity is increased, so that R1270 is preferably in the range of 40 to 50% by weight in order to have an appropriate volumetric capacity. As R290 increases, the volumetric capacity decreases and the temperature gradient increases, so that the mixed refrigerant preferably has a suitable volumetric capacity and a small temperature gradient, and R290 is preferably in the range of 40 to 50% by weight. Since R134a has a lower vapor pressure than R1270 or R290, and R134a increases, the volumetric capacity of the mixed refrigerant decreases and the temperature gradient increases, so that R134a is preferably 10% by weight or less.

According to the mixed refrigerants of Examples 12 and 13 of Table 3, when the composition ratio of R1270 and R290 is 70% by weight to 30% by weight, the volume capacity is 3575kJ / m 3 and the temperature gradient is 0.1 ° C. When the composition ratio of R290 is 90% by weight to 10% by weight, the volume capacity is 3631kJ / m 3 and the temperature gradient is 0.0 ° C., which is not a big difference.

However, according to the mixed refrigerants of Examples 14 and 15 of the present invention, when the composition ratio of R1270 and R134a is 60% by weight to 40% by weight, the volumetric capacity is 3709kJ / m3 and the temperature gradient is 0.4 ° C, whereas the composition ratio of R1270 and R134a is When the weight ratio is 40% by weight to 60% by weight, the volume capacity is 3597kJ / m 3 and the temperature gradient is 3.5 ° C. Therefore, the increase in R134a increases the volumetric capacity and increases the temperature gradient in the mixed refrigerant. After all, the mixed refrigerant of Inventive Example 18, which has a volume capacity similar to that of HCFC22 and has a low temperature gradient, is a suitable composition to replace the existing refrigerants HCFC22 and R407C, but if R134a is too large than 10 wt%, the refrigerant system using the conventional refrigerant is used. You cannot use it.

[Inventive Example 10,11,12,13]

As shown in Examples 10, 11, 12, and 13 of the present invention, when R1270 is increased in the mixed refrigerant, the volume capacity is increased. Therefore, in order to have a volume capacity similar to that of the existing refrigerant, the ratio of R1270 is preferably over 80% by weight.

[Inventive Example 14,15,16]

As shown in Examples 14, 15 and 16 of the present invention, when R1270 is decreased and R134a is increased in the mixed refrigerant composed of R1270 and R134a, the temperature gradient is increased and the volume capacity is decreased. Therefore, in order for the mixed refrigerant to have a volume capacity similar to that of the existing refrigerant and to reduce the temperature gradient, the ratio of R1270 is preferably more than 40% by weight and the ratio of R134a is not more than 60% by weight.

It is to be noted that the term "refrigeration system" used throughout the specification of the present invention is used in the meaning of a refrigerator / air conditioner, unless otherwise specified, that both are used in the same meaning.

According to the mixed refrigerant for R502 and R22 and the refrigeration system using the same according to a preferred embodiment of the present invention having the above-described configuration as a material constituting the mixed refrigerant propylene, propane and ozone layer destruction index of 0.0 and very low global warming index Since 1,1,1,2-tetrafluoroethane is used, there is a remarkable effect of preventing the global ozone layer destruction and global warming even when the refrigerant is leaked or disposed of.

In addition, the mixed refrigerant according to the present invention is mixed with propylene, propane and 1,1,1,2-tetrafluoroethane in an appropriate composition so that the vapor pressure or volumetric capacity of the mixed refrigerant is similar to that of the conventional refrigerant R502 or R22. Therefore, since it can be applied directly without replacing the compressor or modifying the existing refrigeration system, it has the effect of reducing the time and economic cost.

In the mixed refrigerant of the present invention, since the temperature gradient is very small by mixing the proper composition, there is almost no change in the refrigerant pressure due to the phase change of the refrigerant, so that the refrigeration system can be used stably, and the separation of the composition during the outflow of the refrigerant is prevented. It works.

Although the present invention has been described in connection with the above-mentioned preferred embodiments, it is possible to make various modifications or variations without departing from the spirit and scope of the invention. Accordingly, the appended claims will cover such modifications and variations as fall within the spirit of the invention.

1 is a block diagram of a general refrigeration / air conditioner used in the present invention.

Explanation of symbols on main parts of drawing

Qc: direction of heat flow in the condenser (from refrigerant to air)

Qe: Heat flow direction from the evaporator (air to refrigerant)

TS1: evaporator air inlet temperature, TS7: evaporator air outlet temperature

TS3: condenser air outlet temperature, TS6: condenser air inlet temperature

Evaporator: Compressor: Compressor

Condenser: Condenser, Expansion Valve: Expansion Valve

Claims (9)

Mixed refrigerant for refrigeration / air conditioner consisting of 1 to 99 parts by weight of R1270 (propylene), 98 parts by weight of R290 (propane) and 1 to 70 parts by weight of R134a (1,1,1,2-tetrafluoroethane) . The method of claim 1, Mixed refrigerant comprising 1 to 30 parts by weight of R1270 (propylene), 60 to 80 parts by weight of R290 (propane), and 1 to 10 parts by weight of R134a (1,1,1,2-tetrafluoroethane) . The method of claim 1, 40 to 60 parts by weight of R1270 (propylene), 40 to 60 parts by weight of R290 (propane), and 1 to 10 parts by weight of R134a (1,1,1,2-tetrafluoroethane). A mixed refrigerant consisting of 1 to 40 parts by weight of R1270 (propylene) and 60 to 99 parts by weight of R290 (propane) in a refrigeration / air conditioner mixed refrigerant to replace R502 used in a low temperature freezer. delete delete delete delete A refrigeration / air conditioner using one selected from the mixed refrigerants of claim 1.