KR20140091120A

KR20140091120A - Vapor compression refrigeration/air-conditioning equipment with suction line heat exchanger for improving energy efficiency using R1234yf

Info

Publication number: KR20140091120A
Application number: KR1020130001481A
Authority: KR
Inventors: 정동수
Original assignee: 인하대학교 산학협력단
Priority date: 2013-01-07
Filing date: 2013-01-07
Publication date: 2014-07-21

Abstract

The present invention relates to an ozone depletion potential (ODP) for increasing the coefficient of performance (hereinafter referred to as COP) in a vapor compression refrigeration / air-conditioning equipment. And the Global Warming Potential (GWP) is significantly lower than that of existing refrigerants. Therefore, the environmentally friendly R1234yf refrigerant can be used in the form of pure refrigerant or mixed refrigerant, heat pump, chiller, vending machine cooler, water purifier cooler, water heater, etc. (hereinafter referred to as "steam compression refrigeration / air conditioner") using a heat exchanger (hereinafter referred to as SLHX) .

Description

[0001] The present invention relates to a vapor compression refrigeration / air-conditioning equipment using a suction pipe heat exchanger for increasing the performance coefficient of a refrigerant using R1234yf as a working fluid,

The present invention relates to a vapor compression type refrigeration / air conditioning apparatus using an environmentally friendly R1234yf refrigerant as a pure refrigerant or a mixed refrigerant in which the ozone layer decay index is 0 and the global warming index is significantly lower than that of conventional refrigerants, And a suction pipe heat exchanger are used to increase the performance coefficient.

The vapor compression type refrigeration / air conditioner using the R1234yf refrigerant and the suction pipe heat exchanger according to the present invention uses a pure refrigerant of R1234yf or a mixed refrigerant containing R1234yf as a working fluid and at the same time by applying a suction pipe heat exchanger, , Chiller, vending machine cooler, water purifier cooler, water heater, etc., can increase the performance coefficient of the vapor compression type refrigerator / air conditioner up to 6%.

Until now, Chlorofluorocarbon (hereinafter referred to as CFC) and Hydrochlorofluorocarbon (HCFC) derived from methane or ethane have been mainly used as the refrigerant of the vapor compression refrigerating / air-conditioning system, / Heat pump, commercial chiller, etc., HCFC22 having a boiling point of -40.8 ° C and a molecular mass of 86.47 kg / kmol has been most widely used.

In recent years, however, the collapse of the stratospheric ozone layer by CFCs and HCFCs has emerged as an important global environmental issue, and the production and consumption of CFCs and HCFCs, which disrupt stratospheric ozone, are regulated by the Montreal Protocol of 1987. As can be seen in Table 1, the HCFC22 is now free from ODP in 2010 under the Montreal Protocol in developed countries. Therefore, most countries around the world must find and use alternative refrigerants with an ODP of zero.

Recently, not only the problem of ozone depletion but also the problem of global warming has started to grow rapidly, and the Kyoto Protocol of 1997 strongly recommends that GWPs refrain from using high refrigerant. Reflecting this trend, manufacturers of vapor compression refrigerators / air conditioners in the US, Europe, Japan and Korea are attempting to develop and use low GWP refrigerants.

Table 1 shows the environmental index of refrigerants that can replace HCFC22 for air conditioning / heat pumps and commercial chillers. DuPont and Honeywell of the United States have developed and sold a binary mixed refrigerant called R410A that can replace HCFC22 for more than a decade. However, as can be seen in Table 1, this refrigerant has zero ozone depletion index, but the global warming index is higher than that of HCFC22.

In order to prevent global warming, HFC32, which is one third of the conventional HCFC22, has emerged as an alternative refrigerant for HCFC22. However, GWP is higher than that required by environmental groups and is flammable, and the refrigerant discharge temperature It is difficult to use it as a refrigerant of a heat pump operating in winter.

Recently, in Europe, from January 1, 2011, mandatory regulations have been passed for newly manufactured cars to only use refrigerants with a GWP of 150 or less. As a result, automotive air conditioning manufacturers around the world are focusing on developing new refrigerants and automotive air conditioning systems to comply with these mandatory regulations. As part of this effort, a new refrigerant called HFO-1234yf (hereinafter referred to as R1234yf) was developed. One of the best features of R1234yf is that the ODP is 0 and the GWP is very low at 4, so it can meet the EU mandatory requirements. In addition, the R1234yf can be applied to automotive air conditioning systems, which have been commercially available, without any major change, which is advantageous in terms of production and manufacturing.

Thanks to these excellent features, refrigerant manufacturers and vapor compression refrigeration / air conditioner manufacturers can use the long-term environmentally friendly R1234yf instead of HCFC22, R410A, and HFC32 for home air conditioners / heat pumps, commercial / building chillers, vending machines Cooler, water purifier cooler, and water heater.

For a substance to be useful as an alternative refrigerant for existing refrigerants, it should first have a coefficient of performance (COP) similar to that of conventional refrigerants. Here, the performance coefficient (COP) means the total refrigeration effect as compared with the work done to the compressor. The larger the COP, the higher the energy efficiency of the vapor compression type refrigerator / air conditioner.

In the case of vapor compression refrigeration / air conditioning systems, the direct warming effect from the refrigerant itself accounts for about 5% of the total warming effect during the lifetime of the device, and the remaining 95% is the lifetime of the device, usually 20 years This is an indirect warming effect due to the emission of carbon dioxide from the power plant due to the use of electricity.

Table 1 Environmental Index of HCFC22 and HCFC22 Alternative Refrigerants

Refrigerant Ozone layer decay index
(ODP) Global Warming Index
(GWP) HCFC22 0.05 1,700 R410A 0.0 1,890 HFC32 0.0 550 R1234yf 0.0 4

(*) ODP is based on CFC11 set at 1.0.

(**) GWP is based on the assumption that carbon dioxide in the 100th year is 1.0.

Therefore, to solve global warming, which is a global environmental problem, it is most important to reduce the generation of carbon dioxide in the power plant by increasing the coefficient of performance (COP) of the vapor compression refrigeration / air conditioning system. Therefore, COP is one of the most important system performance indicators to be considered when applying environmentally friendly new refrigerants. Refrigerant / air-conditioner manufacturers use environment-friendly products to adjust the compressor and heat exchanger size when the COP of the refrigerant is low and the COP of the refrigerant is lower than ± 5% Is ready to release.

It is an object of the present invention to provide a vapor compression refrigeration / air conditioning apparatus using a suction pipe heat exchanger to improve the performance coefficient while using R1234yf, which is a long-term environmentally friendly refrigerant.

The object of the present invention is achieved by a vapor compression type refrigeration / air conditioning apparatus using R1234yf as a working fluid and including an evaporator, a condenser, a compressor, an expansion valve, and a suction pipe heat exchanger for increasing the performance coefficient .

The present invention also provides a vapor compression refrigeration / refrigeration system using a mixed refrigerant containing R1234yf as a working fluid and including an evaporator, a condenser, a compressor, an expansion valve, and a suction pipe heat exchanger for increasing a coefficient of performance. Can also be achieved by an air conditioning system.

The present invention also provides a vapor compression type refrigeration / air conditioning system, comprising: an evaporator, a condenser, a compressor, an expansion valve, and a suction pipe heat exchanger for increasing the performance coefficient, wherein the R1234yf / R134a mixed refrigerant is used as a working fluid. Device can also be achieved.

The present invention also provides a steam compression refrigeration / air conditioning system comprising a refrigerant mixture of R1234yf / R152a as a working fluid and an evaporator, a condenser, a compressor, an expansion valve, and a suction pipe heat exchanger for increasing a performance coefficient. Device can also be achieved.

The present invention also provides a steam compression refrigeration / air conditioning system comprising a refrigerant mixture of R32 / R1234yf as a working fluid and an evaporator, a condenser, a compressor, an expansion valve, and a suction pipe heat exchanger for increasing a performance coefficient. Device can also be achieved.

The vapor compression refrigeration / air conditioning apparatus includes an air conditioner, a heat pump, a chiller, a vending machine cooler, a water purifier cooler, or a hot water heater.

The vapor compression type refrigeration / air conditioner using the R1234yf refrigerant and the suction pipe heat exchanger according to the present invention uses a pure refrigerant of R1234yf or a mixed refrigerant containing R1234yf as a working fluid and at the same time by applying a suction pipe heat exchanger, , Chiller, vending machine cooler, water purifier cooler, water heater, etc., can be significantly increased up to 6%.

1 is a configuration diagram of a refrigeration / air-conditioning apparatus including an evaporator, a condenser, a compressor, an expansion valve, and a suction pipe heat exchanger (SLHX) according to the present invention.
2 is a graph showing changes in the coefficient of performance of refrigerants in the case of 'SLHX is absent' and 'SLHX is applied' in the vapor compression refrigeration / air conditioning system.

Hereinafter, a configuration of a vapor compression type refrigeration / air conditioning apparatus using an R1234yf according to a preferred embodiment of the present invention as a working fluid and using a suction pipe heat exchanger to increase the performance factor will be described in detail with reference to the accompanying drawings.

The present invention relates to a vapor compression type refrigeration / air conditioning apparatus using an environmentally friendly R1234yf refrigerant as a pure refrigerant or a mixed refrigerant in which the ozone layer decay index is 0 and the global warming index is significantly lower than that of conventional refrigerants, And a suction pipe heat exchanger are used to increase the performance coefficient. The vapor compression type refrigeration / air conditioner includes a vapor compression type air conditioner / heat pump, chiller, vending machine cooler, water purifier cooler, water heater, and the like.

The present invention relates to the application of a suction line heat exchanger (SLHX) to improve the performance of a vapor compression refrigeration / air conditioning system using a long-term environmentally friendly refrigerant R1234yf. To accomplish this object, the present inventor used a program that simulates the performance of a refrigeration / air conditioning system. This program is a Cycle-D refrigeration / air conditioning cycle analysis program developed by the National Institute of Standards and Technology (NIST). This is a proven program widely used by leading companies, universities, and research institutes around the world.

One of the important factors determining the accuracy of this program is the properties of the refrigerant. This program calculates the properties of all refrigerants using the REFPROP program, which is based on the US, Japan and EU. The REFPROP program, developed by the National Institute of Standards and Technology (NIST), has proved its accuracy and applicability, making it the most widely used program in leading companies, research institutes and universities worldwide. The program and material used here are the latest models with the most recent data.

1 is a configuration diagram of a refrigeration / air-conditioning apparatus including an evaporator, a condenser, a compressor, an expansion valve, and a suction pipe heat exchanger (SLHX) according to the present invention.

The suction pipe heat exchanger (SLHX) is a device used mainly to increase the refrigerating effect by exchanging the liquid refrigerant from the condenser and the gaseous refrigerant entering the compressor from the evaporator. However, SLHX has not been used at all in the past half-century for home and car air conditioners / heat pumps, commercial / building / industrial chillers.

Referring first to the flow of refrigerant in the refrigeration / air conditioning system, the refrigerant in state 7 enters the evaporator in an abnormal state (two liquid and two phases mixed) as shown in FIG. At this time, the refrigerant in an abnormal state evaporates while exchanging heat with the secondary fluid, and generally exits the evaporator in an overheated steam state (state 1). Steam refrigerant from the evaporator is further heated in the SLHX by heat exchange with liquid refrigerant exiting the condenser and enters the compressor at a temperature close to ambient temperature (State 2). Usually at the outlet of the condenser the refrigerant is subcooled (state 6). The supercooled refrigerant exiting the condenser undergoes heat exchange with the superheated steam at the compressor inlet at the SLHX and is further subcooled (state 9). The liquid refrigerant finally expands through the expansion valve and completes one cycle.

Table 2 shows the relationship between the HCFC22 and R410A, HFC32, R1234yf, R1234yf / R134a, R1234yf / R152a, R32 / R1234yf refrigerant that can replace it with the existing HCFC22 under the same refrigeration capacity in the summer cooling condition of the refrigerator / The results are summarized in the case of 'without SLHX' and 'with SLHX'. In case of SLHX in the cycle simulation, the heat exchanger effectiveness of SLHX is assumed to be 90%.

Table 2 shows the performance coefficients of 14 refrigerants without 'SLHX' and 'with SLHX'

(Cooling operation during summer: evaporator refrigerant temperature: 7 캜, condenser refrigerant temperature: 45 캜)

Refrigerant No SLHX With SLHX COP _diff.
(%) GWP COP _c COP _c One HCFC22 3.97 3.92 -1.3 1700 2 R410A 3.70 3.68 -0.5 1890 3 HFC32 3.78 3.65 -3.4 550 4 R1234yf 3.87 4.10 5.9 4 5 60% R1234yf /
40% R134a 3.88 4.05 4.4 574 6 85% R1234yf /
15% R134a 3.87 4.08 5.4 218 7 90% R1234yf /
10% R134a 3.87 4.08 5.4 147 8 50% R1234yf /
50% R152a 4.01 4.09 2.0 72 9 80% R1234yf /
20% R152a 3.93 4.08 3.8 31 10 90% R1234yf /
10% R152a 3.90 4.09 4.9 18 11 10% R32 /
90% R1234yf 3.85 4.04 4.9 59 12 20% R32 /
80% R1234yf 3.80 3.93 3.4 113 13 30% R32 /
70% R1234yf 3.75 3.84 2.4 168 14 40% R32 /
60% R1234yf 3.73 3.78 1.3 222

(Calculated by the Cycle-D program of the American National Standards Institute)

○ COP _c : Cooling performance coefficient

○ COP _diff : Difference in performance between 'Without SLHX' and 'With SLHX'

○ SLHX: Suction line heat exchanger

(*) In mixed refrigerant,% of composition means weight%.

As mentioned above, there has been a recent trend of using environmentally friendly R1234yf for air conditioner / heat pump, chiller and vending machine cooler due to global warming problem, and R1234yf is mixed with R1234yf like R1234yf / R134a, R1234yf / R152a, R32 / R1234yf, There is also a tendency to use it as a constituent of the.

As shown in Table 2, the GWP of these mixed refrigerants is similar to or lower than the GWP of HFC32, which is currently being considered as an alternative refrigerant for HCFC22.

Figure 2 shows COP changes for the 14 refrigerants in Table 2, with or without SLHX.

Referring to Table 2 and FIG. 2, it can be seen that the use of SLHX for conventional refrigerants such as HCFC22, R410A and HFC32 results in a reduction in COP. For existing refrigerants such as HCFC22, R410A, and HFC32, SLHX was not used at all for refrigeration / air conditioning systems that used HCFC22, R410A, and HFC32 for the past half century because COPs were rather reduced.

However, as shown in Table 2 and Fig. 2, when using R1234yf as a working fluid, the COP increases by about 6% when SLHX is applied to a vapor compression refrigeration / air conditioning system.

The 6% increase in COP means that the electricity consumption of the steam compression type refrigerator / air conditioner is reduced accordingly. Considering that many millions of vapor compression refrigeration / air conditioning units such as air conditioner / heat pump, chiller, vending machine cooler are manufactured every year and use a lot of electricity worldwide, 6% increase in performance and decrease of energy consumption Is very important for energy conservation / conservation and global environmental protection.

As can be seen in Table 2, this phenomenon was similar in R1234yf / R134a, R1234yf / R152a, R32 / R1234yf mixed refrigerants using R1234yf as one component.

For these mixed refrigerants, the larger the composition of R1234yf, the greater the increase in the coefficient of performance due to the use of SLHX. Therefore, for a steam compression refrigeration / air conditioner using pure refrigerant R1234yf or R1234yf, the SLHX increases the performance factor by about 6%.

This phenomenon is very unusual. As described above, in the case of conventional refrigerants such as HCFC22, R410A, and HFC32, the refrigerant / air conditioner using HCFC22, R410A, HFC32 for the past half century due to the reduction of COP by using SLHX No SLHX was used at all.

However, when R1234yf is used as a refrigerant, the coefficient of performance is increased as described above. Therefore, it is essential to apply the suction pipe heat exchanger only when R1234yf (or mixed refrigerant containing R1234yf) is used as the working fluid.

Table 3 summarizes the results of calculating the performance of the same refrigerants by using the Cycle-D program in the winter heating condition of the vapor compression type refrigerator / air conditioner for 'when there is no SLHX' and 'when there is SLHX' will be.

Table 3 Performance curves of 14 refrigerants without SLHX and with SLHX

(Winter heating driving condition: evaporator refrigerant temperature: -7 ° C, condenser refrigerant temperature: 41 ° C)

Refrigerant No SLHX With SLHX COP _diff.
(%) GWP COP _h COP _h One HCFC22 3.94 3.90 -1.0 1700 2 R410A 3.75 3.74 -0.3 1890 3 HFC32 3.81 3.69 -3.1 550 4 R1234yf 3.82 4.05 6.0 4 5 60% R1234yf /
40% R134a 3.83 4.02 5.0 574 6 85% R1234yf /
15% R134a 3.82 4.04 5.8 218 7 90% R1234yf /
10% R134a 3.82 4.04 5.8 147 8 50% R1234yf /
50% R152a 3.95 4.03 2.0 72 9 80% R1234yf /
20% R152a 3.88 4.04 4.1 31 10 90% R1234yf /
10% R152a 3.85 4.05 5.2 18 11 10% R32 /
90% R1234yf 3.81 4.01 5.2 59 12 20% R32 /
80% R1234yf 3.80 3.94 3.7 113 13 30% R32 /
70% R1234yf 3.77 3.86 2.4 168 14 40% R32 /
60% R1234yf 3.77 3.82 1.3 222

○ COP _h : Heating performance coefficient

○ SLHX: Suction line heat exchanger

(*) In mixed refrigerant,% of composition means weight%.

As can be seen in Table 3, in the case of a vapor compression refrigerating / air-conditioning system using a pure refrigerant containing R1234yf or R1234yf, the suction-pipe heat exchanger (SLHX) It can be seen that the performance increase is 6%.

Qcond: Heat flow direction in the condenser (refrigerant → air)
Qevap: Direction of heat flow in the evaporator (air → refrigerant)
TS1: Evaporator air inlet temperature, TS7: Evaporator air outlet temperature
TS3: Condenser air outlet temperature, TS6: Condenser air inlet temperature
Evaporator: Evaporator, Compressor: Compressor
Condenser: Expansion valve, Expansion valve, SLHX: Suction pipe heat exchanger

Claims

R1234yf is used as a working fluid and comprises an evaporator, a condenser, a compressor, an expansion valve, and a suction pipe heat exchanger for increasing the performance coefficient.

A condenser, a compressor, an expansion valve, and a suction pipe heat exchanger for increasing the coefficient of performance, using a mixed refrigerant containing R1234yf as a working fluid.

And a suction pipe heat exchanger for using the R1234yf / R134a mixed refrigerant as a working fluid and for increasing an evaporator, a condenser, a compressor, an expansion valve, and a performance coefficient.

An evaporator, a condenser, a compressor, an expansion valve, and a suction pipe heat exchanger for increasing the performance coefficient, wherein the R1234yf / R152a mixed refrigerant is used as a working fluid.

And a suction pipe heat exchanger for using the R32 / R1234yf mixed refrigerant as the working fluid, the evaporator, the condenser, the compressor, the expansion valve, and the performance coefficient enhancing device.

The steam compression refrigeration / air conditioning system according to any one of claims 1 to 5, wherein the vapor compression type refrigeration / air conditioning apparatus includes an air conditioner, a heat pump, a chiller, a vending machine cooler, a water purifier cooler, Device.