KR100212117B1 - Cooling system with mixing refrigerant - Google Patents

Abstract

이하, 디플루오로메탄(CH₂F₂) 40

이하와 1,1,1,2-테트라플루오로에탄 20∼80

또는 디플루오로메탄(CH₂F₂) 5∼40

, 펜타플루오로에탄(C₂HF₅) 5∼40

, 1,1,1,2-테트라플루오로에탄 20∼90

로된 비공비성 혼합냉매(Non-Azeotropic Refrigerant Mixtures) 및 이 비공비성 혼합물을 냉매로 하고 흡입관 열교환기(Suction Line Heat Exchanger)를 사용하는 냉동시스템에 관한 것이다.The present invention relates to 1,1- Daefluoroethane 40

Hereinafter, difluoromethane (CH ₂ F ₂ ) 40

20 to 80 with 1,1,1,2-tetrafluoroethane

Or difluoromethane (CH ₂ F ₂ ) 5 to 40

, Pentafluoroethane (C ₂ HF ₅ ) 5-40

, 1,1,1,2-tetrafluoroethane 20 to 90

Non-Azeotropic Refrigerant Mixtures and a refrigeration system using the azeotropic mixture as a refrigerant and using a suction line heat exchanger.

The mixed refrigerant of the present invention has no possibility of ozone depletion and exhibits a similar or superior effect in terms of the freezing capacity of the refrigeration performance coefficient compressor as an alternative refrigerant of the existing R-22 in a refrigerator using a combined heat exchanger.

Description

Refrigeration system using mixed refrigerant and mixed refrigerant

이하, 디플루오로메탄 40

이하와 1,1,1,2-테트라플루오로에탄 20∼80

로 구성되거나, 디플루오로메탄 5∼40

, 펜타플루오로에탄 5∼40

와 1,1,1,2-테트라플루오로에탄 20∼90

로 구성된 오존층 파괴능이 없는 냉동기용 비공비성 혼합냉매 및 이 혼합냉매를 사용하는 냉동시스템에 관한 것이다.The present invention relates to an azeotropic mixed refrigerant consisting of a plurality of halogenated hydrocarbons used in a refrigerator, an air conditioner and a heat pump, and a refrigeration using the mixed refrigerant and a suction line heat exchanger (hereinafter referred to as SLHX). It relates to a system (Refrigeration System). More specifically, 1,1-difluoroethane 40

Or less, difluoromethane 40

20 to 80 with 1,1,1,2-tetrafluoroethane

Or difluoromethane 5-40

Pentafluoroethane 5-40

And 1,1,1,2-tetrafluoroethane 20 to 90

An azeotropic mixed refrigerant for a refrigerator having no ozone depleting capacity, and a refrigeration system using the mixed refrigerant.

The present invention relates to a mixed refrigerant used in a refrigerator using a suction tube heat exchanger. More specifically, the present invention relates to a refrigeration system using a mixed refrigerant capable of replacing monochlorofluoromethane (CHCIF2: hereinafter referred to as R-22) in a refrigeration system and an alternative refrigerant of R-22 using SLHX.

Conventionally, chlorofluorocarbons (hereinafter referred to as CFCs) and hydrogenated CFCs (hereinafter referred to as CFCs) derived from methane or ethane as refrigerants such as refrigerators, air conditioners, and heat pumps are referred to as HCFCs. ) Has been used mainly, and R-22, which has a boiling point of -40.8 ° C and HCFC, has been widely used as a refrigerant for building air conditioners, large-scale refrigeration systems, and low-temperature show cases.

Recently, however, the destruction of the ozone layer in the stratosphere by CFCs has emerged as an important global environmental protection problem, and the use and production of chlorofluorocarbons (CFCs), which are completely halogenated and potentially ozone depleted, are greatly restricted by the Montreal Protocol. In the near future, their use and production will be banned worldwide.

If the Ozone Depletion Potential (ODP) of trichlorofluoromethane (CCL3F, R-11) is defined as 1, the ODP of R-22 is 0.05, even though R-2 is completely halogenated. Although not CFCs, they are widely used in air conditioners and heat pumps, and are expected to have a significant impact on human life in the future, such as CFCs, which would prohibit their production and use under the Montreal Protocol. Therefore, at present, the ODP is 0.0, and the rapid development of a refrigeration fluid that can be used as a substitute for R-22 is desired.

As a substitute for R-22, various types of mixed refrigerants have been proposed. However, their production and use are not yet directly regulated, but they are based on the HCFC, which has been restricted in the Montreal Protocol (Korean Patent Publication No. 91-989, PCT / 91 / 04100 Korean Publication No. 93-701562) There is a problem that can not be used as a substitute in the long term.

In addition, as a substitute for R-22, difluoromethane (hereinafter referred to as HFC-32 or R-32) and pentafluoroethane (hereinafter referred to as HFC-125 or R-125) and 1,1,1,2 An azeotrope of tetrafluoroethane (hereinafter referred to as HFC-134a or R-134a) has been proposed, namely Klea-60 and Klea-61 at ICI UK and AC-9000 at DuPont USA. It was announced under the name.

와 HFC-125 40

및 HFC-134a 40

로 된 비공비혼한물(Non-Near Azortropic Mixtures)이고, Klea-61은 R-32 10

와 R-125 70

및R-134a 20

된 비공비혼합물이며, AC-9000은 HFC-32 45

와 HFC-125 25

및 HFC-134a 52

로 된 비공비혼합물이다. 이후로는 별다른 언급이 없는 한 혼합냉매의 조성은 모두 질량비를 의미한다.Klea-60 is HFC-32 20-

With HFC-125 40

And HFC-134a 40

Non-Near Azortropic Mixtures, Klea-61 is R-32 10

With R-125 70

And R-134a 20

Non-azeotropic mixture, AC-9000 is HFC-32 45

With HFC-125 25

And HFC-134a 52

It is an azeotropic mixture of Thereafter, unless otherwise stated, the composition of the mixed refrigerants means mass ratio.

To be useful as an alternative to R-22, it must first have a vapor pressure similar to that of R-22 for use without major modifications to existing R-22 compressors, and a similar Coefficient of Performance (COP). Must have However, it is known that none of the proposed alternative refrigerants surpasses the performance of the existing R-22 in terms of COP and compressor capacity. In this case, the COP means total refrigeration compared to the work applied to the compressor, and the larger the COP, the better the energy efficiency of the refrigerator.

On the other hand, in the design of the refrigerator, the most important factor with COP is the freezing volume capacity (hereinafter referred to as VC). VC is the refrigeration effect per unit volume (kj / m 3), which is proportional to the vapor pressure and represents the size of the compressor. If the replacement refrigerant is capable of freezing the existing R-22, it is very advantageous for the manufacturer to be able to build a freezer without changing the size of the compressor. However, if the refrigeration capacity of the alternative refrigerant is greater than R-22, the compressor size should be small, and the compressor should be redesigned basically because of the high pressure on the condenser side, which requires a lot of manpower and development cost.

Since HFC-32 is a combustible material and high vapor pressure component of R-22 alternative mixed refrigerant, it is recommended to reduce the proportion of HFC-32 as much as possible when constructing mixed refrigerant.

Conventional R-22 alternative refrigerants have poor performance and poor energy efficiency in terms of COP or compressor capacity. In addition, the replacement refrigerant is different from the existing R-22 in terms of VC, so the compressor has to be redesigned, which requires a manpower and development cost.

Therefore, the present inventors have studied to solve the above problems, by selecting the components of the mixed refrigerant from R-32, R-134a, R-152a and R-125 and maintaining the proper composition, in all aspects than the conventional alternative refrigerant Excellent mixed refrigerants have been developed to complete the present invention. In addition, the mixed refrigerant of the present invention is closer to the COP of the R-22 and the VD of the compressor than the commercially available R-22 alternative azeotrope, or in most cases has a similar refrigerating capacity as those of the refrigeration system using the same The company has developed a refrigeration system that can be replaced immediately without the need for redesign.

이하, 디플루오로메탄 40

이하와 1,1,1,2-테트라플루오로에탄 20∼80

로 구성된 비공비성 혼합냉매를 제공하는 것이다.The object of the present invention is 1,1-difluoroethane 40

Or less, difluoromethane 40

20 to 80 with 1,1,1,2-tetrafluoroethane

It is to provide an azeotropic mixed refrigerant consisting of.

, 펜타플루오로에탄 5∼40

와 1,1,1,2-테트라플루오로에탄 20∼90

로 된 비공비성 혼합냉매를 제공하는 것이다.Another object of the present invention is difluoromethane 5-40

Pentafluoroethane 5-40

And 1,1,1,2-tetrafluoroethane 20 to 90

It is to provide a non-azeotropic mixed refrigerant.

Still another object of the present invention is to provide a refrigeration system using the above mixed refrigerant and using a suction tube heat exchanger.

1 is a block diagram of a refrigerator or a heat pump using the suction tube heat exchanger (SLHX) proposed in the present invention.

FIG. 2 is a comparison of the refrigerant coefficient of cold refrigerant (COP) proposed for R-22 and R-22 alternative refrigerants with and without SLHX.

3 is a comparison of the refrigerant volumetric capacity (VC) of the compressors proposed as R-22 alternative refrigerants with and without SLHX.

FIG. 4 is a comparison of frozen refrigerant coefficient (COP) of mixed refrigerants with and without SLHX.

5 is a comparison of the compression of the mixed refrigerants compared with the use of the freezing volume capacity (VC) with and without the SLHX.

* Explanation of symbols for main parts of the drawings

1: Evaporator

2: Suction Line Heat Exchanger

3: Condenser 4: Compressor

5: saturated evaporation band 6: condensation band

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

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

TS1: Evaporator air outlet temperature TS7: Evaporator air outlet temperature

TS3: condenser air inlet temperature TS6: condenser air inlet temperature

이하, 디플루오로메탄 40

이하와 1,1,1,2-테트라플루오로에탄 20∼80

로 구성되거나, 디플루오로메탄 5∼40

, 펜타플루오로에탄 5∼40

와 1,1,1,2-테트라플루오로에탄 20∼90

로 구성된다.Non-azeotropic mixed refrigerant of the present invention is 1,1-difluoroethane 40

Or less, difluoromethane 40

20 to 80 with 1,1,1,2-tetrafluoroethane

Or difluoromethane 5-40

Pentafluoroethane 5-40

And 1,1,1,2-tetrafluoroethane 20 to 90

It consists of.

In order to develop R-22 alternative refrigerants, we first developed a simulator (Simulatior) that simulates the performance of a domestic air conditioner (or heat pump). 1 is a block diagram of a heat pump using a suction tube heat exchanger (SLHX) used in the present invention. The heat pump modeled in the present invention also has an evaporator (1), a condenser (3), a compressor (4) basically like the heat pump generally used, and the saturated evaporation zone (5) of the refrigerant in the evaporator and the condenser, It has a condensation zone 6. If the suction tube heat exchanger 2 is installed between the evaporator 1 and the condenser 3, the temperature of the hot liquid at the end of the condenser 3 is lowered and the temperature of the cold gas at the end of the evaporator 1 is increased. . This process increases the volumetric capacity of the COP and compressor. In the drawings, a symbol A and B denotes a heat transfer flow direction between a refrigerant and air.

In this simulator, thermodynamic and heat transfer analyzes of the elements constituting the air conditioner, such as heat exchangers and compressors, were performed (see FIG. 1). Each individual product was tested and finally a complete program was developed that combined them all. One of the important factors that determine the accuracy of the developed program is the properties of the refrigerants. The simulator calculates the properties of all refrigerants using the Carnahan-Starling-De santis (CSD) state equation, which is the standard in the United States and Japan. This CSD state equation was developed by the American Institute of Standards, and its accuracy and applicability have already been demonstrated. The design and input data for the development and execution of the simulator program used existing actual data. Of course, the simulator can predict the performance of a real system well under given standard conditions.

정도 증가하고 압축기의 토출온도(Compressor Discharge Temperature)가 20∼30℃ 증가한다.(제2도 참조) 또한 이와 비슷한 경향이 VC의 경우에도 나타난다. (제3도 참조)Based on the results of the present inventors using the simulator, COP of each pure refrigerant shows a great difference when the SLHX is not used in the case of the pure refrigerant, but the overall COP is 5 when the SLHX is not used. To 10

The temperature increases and the compressor discharge temperature increases by 20 – 30 ° C (see Figure 2). Similar trends also appear in the case of VC. (See Figure 3)

In view of the long-term prospect, the present inventors have determined that the replacement refrigerant must be HFC (Hydrofluoro-carbon), and therefore, a combination of HFCs R-152a, R-134a and R-32 and HFCs R-32 and R-125 The combination of R-134a allows R-22 to be replaced.

이하, R-32 40

이하, R-134a 20∼80

와 R-32 5∼40

, R-125 5∼40

, R-134a 20∼90

의 혼합냉매는 오존파괴가능성이 전혀 없으며(ODP=0), SLHX를 사용하지 않는 기존의 냉동기에서 R-22에 비하여, 다음 표 1, 2에서 나타내고 있는 바와같이, 매우 우수한 성능을 나타낸다. R-22에 비해 COP는 4∼5

정도까지 증가하며, VC는 비슷하거나 18%정도 증가하며, 압축기 토출온도는 6∼11

정도 낮아서 매우 좋은 것으로 평가되었다.The mixed refrigerant of the composition proposed by the present inventors has a freezing capacity similar to that of the conventional R-22, and at the same time, the grade coefficient is higher than that of the conventional R-22. According to the research results of the present inventors, R-152a 40

Hereinafter, R-32 40

Hereinafter, R-134a 20-80

And R-32 5-40

, R-125 5-40

, R-134a 20-90

The mixed refrigerant of has no potential for ozone depletion (ODP = 0) and exhibits very good performance, as shown in the following Tables 1 and 2, compared to R-22 in conventional refrigerators that do not use SLHX. COP is 4-5 compared to R-22

VC is similar or increased by 18%, and compressor discharge temperature is 6 ~ 11.

Low enough and very good.

Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not intended to be limited to these Examples.

EXAMPLE

The physical properties of the mixed refrigerant of the present invention when the mixed refrigerant of the specific composition is used with or without the SLHX are shown in Tables 1 and 2.

○ VC: Volumetric capacity of compressor

○ GTD: Grading Temperature Difference

○ T _dis : Compressor discharge temperature (lower is better if possible considering the stability of chiller oil, etc.)

○ P _dis : Compressor discharge pressure (lower is better if possible considering the stability of condenser piping, difficulty of compressor design, etc.)

○ Cop D _iff : Difference in freezing coefficient compared to R-22

○ Vc d _iff : Difference in compressor capacity compared to R-22

As shown in Figure 2, in order to further improve the VC and COP, it is recommended to use a suction tube heat exchanger (SLHX). In the present invention, as shown in FIG. 1, SLHX refers to a device for allowing the hot liquid and the cold gas at the end of the evaporator to exchange heat with each other.

정도까지 증가한다. 반면에 R-22, R-32, RC-270의 성능은 거의 변화가 없거나 2∼3

정도만 증가한다. 그러므로, 대체 혼합 냉매 중 R-125, R-143a, R-134a, R-290, R-1270 등을 포함하는 것들은 SLHX를 사용하여 획기적인 성능 증대를 이룰 수 있다. 제2도에서 유의해야 할 점은 SLHX가 사용되는 경우에 모든 냉매들의 COP가 거의 같다는 점이다. 따라서 R-125 같은 냉매도 SLHX를 사용하여 시스템의 최적화를 이루면 기존의R-22와 같은 수준의 열효율을 낼 수 있을 것으로 판단된다.2 to 5 show how the capacity of the COP and the compressor changes with and without SLHX for the nine pure refrigerants including R-22 and the mixed refrigerants proposed in the present invention. As the figures show, with the SLHX the COP and compressor capacity of the R-125, R-143a, R-134a, R-290, and R-1270 is as high as 17

Increases to a degree. On the other hand, the performance of the R-22, R-32, and RC-270 is almost unchanged, or 2-3.

Only increase the degree. Therefore, those containing R-125, R-143a, R-134a, R-290, R-1270, etc. of the alternative mixed refrigerants can achieve a significant performance increase using the SLHX. It should be noted in FIG. 2 that the COPs of all refrigerants are approximately equal when SLHX is used. Therefore, if the refrigerant such as R-125 is optimized by using SLHX system, it will be able to achieve the same thermal efficiency as the existing R-22.

정도 증가한다. 한편 SLHX를 사용할 수 없는 기존의 R-22 시스템에 비하면 COP가 무려 7∼11

나 증가하며 VC는 같거나 조금 작다. 압출기 토출온도는 SLHX를 사용할 수 없는 기존의 R-22시스템(83.3℃, 표 1참조)보다 15∼20℃ 정도 높게 된다. 그러나 새로운 윤활유를 사용하고 SLHX의 크기를 조절하면 이것도 그리 큰 문제가 되지는 않을 것이다.Table 2 below summarizes the performance of alternative mixed refrigerants obtained with SLHX. COP is 5-6 compared to without SLHX

Increases. On the other hand, compared to the existing R-22 system which cannot use SLHX, COP is 7 ~ 11.

I increase and VC is the same or a little smaller. The extruder discharge temperature is about 15 to 20 ° C higher than the existing R-22 system (83.3 ° C, see Table 1) where SLHX cannot be used. But if you use a new lubricant and scale the SLHX, this won't be too much of a problem.

정도 증가하며 이때의 압축기 토출온도도 흡입관 열교환기를 사용하지 않은 R-22의 경우보다 낮아서 시스템의 신뢰성에 아무 문제가 없을 것으로 판단된다. 한편 R-152a/R-134a/R-32 혼합냉매는 R-22나 타사의 제품보다 COP가 7

정도 높으며 냉동용량은 5

정도 낮고, 압축기 토출온도는 모두 R-22보다 낮다. 이 냉매의 경우에 COP가 크게 증가하므로 압축기를 5

정도만 크게 하면 지구환경보존에 크게 기여할 수 있을 것이다. 한편 흡입관 열교환기를 사용하면 COP가 1∼2

정도 증가하며 이때의 압축기 토출온도도 흡입관 열교환기를 사용하지 않은 R-22의 경우보다 낮아서 시스템의 신뢰성에 아무 문제가 없을 것으로 판단된다.Finally, to support the theoretical results, the performance of refrigerants was measured directly by producing a water-cooled heat pump with a 1-ton refrigeration capacity. The evaporator and condenser were made in the form of double tubes, and the compressor was hermetically sealed. Table 3 below shows the various data taken with and without the suction tube heat exchanger during the system experiment. As can be seen from the table, the proposed R-32 / R-125 / R-134a mixed refrigerant has a higher COP, similar or higher freezing capacity, and compressor discharge temperature than R-22. Lower than When using suction pipe heat exchanger, COP is 1 ~ 2

In this case, the compressor discharge temperature is also lower than that of R-22 without the suction tube heat exchanger. Therefore, there is no problem in the reliability of the system. On the other hand, R-152a / R-134a / R-32 mixed refrigerants have 7 COP than R-22 and other products.

High and the freezing capacity is 5

Low and all compressor discharge temperatures are lower than R-22. In the case of this refrigerant, the COP increases significantly,

Larger scale will greatly contribute to global environmental preservation. On the other hand, if the suction tube heat exchanger is used, the COP is 1 to 2

In this case, the compressor discharge temperature is also lower than that of R-22 without the suction tube heat exchanger. Therefore, there is no problem in the reliability of the system.

WO SLHX: When not using SLHX, WI SLHX: When using SLHX

The mixed refrigerant of the present invention has no possibility of destroying ozone and shows a similar or superior effect in terms of the freezing capacity of the refrigeration performance coefficient compressor as an alternative refrigerant of the existing R-22 in a refrigerator using a suction tube heat exchanger.

Claims (4)

1,1-difluoroethane 40 in mixed refrigerants for freezers

Or less, difluoromethane 40

20 to 80 with 1,1,1,2-tetrafluoroethane

An azeotropic mixed refrigerant consisting of: 1,1-difluoroethane 40 in refrigeration systems

Or less, difluoromethane 40

20 to 80 with 1,1,1,2-tetrafluoroethane

A refrigeration system using an azeotropic mixed refrigerant consisting of a cold vessel and a suction tube heat exchanger. In a mixed refrigerant for a refrigerator comprising difluoromethane, pentafluoroethane, or 1,1,1,2-tetrafluoroethane, difluoromethane 5 to 40

Pentafluoroethane 5-40

And 1,1,1,2-tetrafluoroethane 20 to 90

An azeotropic mixed refrigerant consisting of: In a refrigeration system using a three-component mixed refrigerant consisting of difluoromethane, pentafluoroethane and 1,1,1,2-tetrafluoroethane as a refrigerant for a freezer, difluoromethane 5 to 40

Pentafluoroethane 5-40

And 1,1,1,2-tetrafluoroethane 20 to 90

A refrigeration system using an azeotropic mixed refrigerant consisting of a refrigerant and a suction tube heat exchanger.

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