KR100718666B1 - Mixed hydrocarbon refrigerant composition for refrigerating system - Google Patents

Abstract

The present invention relates to a hydrocarbon-based mixed refrigerant composition for a refrigeration system, propane (C ₃ H ₈ ) 70 ~ 90wt%, DME ((CH ₃ ) ₂ O) 3 ~ 8wt% and propylene (C ₃ H ₆ ) 7 ~ 22 wt%. This provides a hydrocarbon-based mixed refrigerant composition for a refrigeration system that is environmentally friendly and not only applicable to existing refrigerator systems but also has excellent thermodynamic performance.

Description

Mixed hydrocarbon refrigerant composition for refrigerating system

The present invention relates to a hydrocarbon-based mixed refrigerant composition for a refrigeration system. More specifically, the present invention relates to a hydrocarbon-based mixed refrigerant composition for an environmentally friendly refrigeration system which minimizes the impact on global ozone layer destruction and global warming.

In refrigerant compression type refrigeration systems used in electric freezers, refrigerators, air conditioners, refrigeration or freezing warehouses, hydrocarbon-based refrigerants (CFC, HCFC) containing fluorine atoms and chlorine atoms have been used for a long time. When such CFCs or HCFCs are released into the atmosphere by their chlorine atoms, they are known to destroy the ozone layer in the stratosphere. In recent years, their use has been banned or restricted worldwide.

Therefore, the use of HFC without the chlorine atom with a low ozone layer destruction index instead of CFC is increasing. However, HFC has a low ozone layer destruction index but a long remaining life in the atmosphere, which brings about a greenhouse effect, which leads to a high global warming index, and increases the proportion of hydrogen contained in the molecule. It is considered insufficient as a complete substitute for.                         

Recently, natural hydrocarbons, which contain only chlorine and fluorine atoms and have an ozone depletion index of 0.0 and a global warming index that is significantly lower than existing CFCs and HFCs, have attracted attention as alternative refrigerants. It is trying to use.

Among these hydrocarbons, methane, ethane, propane, butane, isobutane, and propylene have been recognized as suitable refrigerants, and they are not only environmentally friendly in terms of global warming and ozone depletion, but also thermodynamic characteristics (large evaporation latent heat). ) Is excellent, non-toxic, chemically stable, and exhibits adequate mixing with mineral oils that are widely used. In addition, it is inexpensive because the specific volume is large, and the refrigerant injection amount can be significantly reduced. The compressor load is low because the condensation pressure is low, and the compressor discharge temperature is low.

However, these natural hydrocarbons all have the disadvantage of being flammable. In order to cope with this flammability, additional safety equipment is required, but since the amount of refrigerant is only about 1 kg in domestic or industrial air conditioners or freezers, the possibility of explosion due to refrigerant leakage is rare. The standard for AIN 7300 has been established to expand the use of natural hydrocarbons.

On the other hand, another disadvantage of natural hydrocarbons is that the volume of the refrigerant is larger than that of the conventional refrigerant, and the stroke volume of the compressor must be increased, and the viscosity of the refrigerant is small, so that the length of the capillary tube must be increased or the diameter must be reduced. In other words, they cannot be replaced by existing systems.

Accordingly, an object of the present invention is to provide a composition of a hydrocarbon-based mixture refrigerant for a refrigeration system that can be applied without alteration of the existing refrigeration system by exhibiting an extremely low and high thermodynamic properties of ozone layer destruction index and global warming index.

In order to achieve the above object, the present invention contains 70 to 90 wt% of propane (C ₃ H ₈ ), 3 to 8 wt% of DME ((CH ₃ ) ₂ O), and 7 to 22 wt% of propylene (C ₃ H ₆ ). Provided is a hydrocarbon-based mixed refrigerant composition for a refrigeration system. Hereinafter, the hydrocarbon-based mixed refrigerant composition according to the present invention will be described in detail.

The inventor of the present invention, propane 80wt%, D.M.E. Hydrocarbon-based mixed refrigerant compositions containing 5wt% and 15wt% of propylene were prepared and applied to existing general household air conditioners, and R-22, a conventional CFC refrigerant, was tested under the same conditions as a comparative example.

Table 1 shows the evaporation pressure, density, and enthalpy (evaporation latent heat) according to temperature change of R-22 as a reference. Table 2 shows the present invention propane 80wt%, D.M.E. Evaporation pressure, density, enthalpy (evaporation latent heat) according to the temperature change of the mixed refrigerant composition containing 5wt% and 15wt% of propylene. As can be seen from Table 1 and Table 2, the mixed refrigerant composition of the present invention shows an equivalent level of evaporation pressure as compared to R-22. In addition, it can be seen that the mixed refrigerant composition of the present invention has an enthalpy (evaporation latent heat) of about 2 times or more, and a specific volume is remarkably high. Therefore, the mixed refrigerant composition of the present invention has a level of evaporation pressure similar to that of R-22, and thus can be replaced with a refrigerant having characteristics similar to those of R-22. In addition, the enthalpy (evaporation latent heat) is higher and the density is significantly lower than that of R-22, thereby increasing the freezing effect per unit mass flow rate.

TABLE 1

Temp Pressure (V) Density (L) Density (V) Enthalpy (V-L) [C] [MPa] [kg / m ³ ] [kg / m ³ ] [kJ / kg] -40 0.1052 1407 4.873 233.2151 -30 0.1639 1377 7.379 226.82 -20 0.2453 1347 10.79 220.06 -10 0.3548 1315 15.32 212.8 0 0.498 1282 21.23 205 10 0.6809 1247 28.82 196.73 20 0.91 1210 38.48 187.64 30 1.192 1171 50.7 177.68 40 1.534 1129 66.19 166.56 50 1.943 1082 85.95 154.2

TABLE 2

Temp Pressure (V) Density (L) Density (V) Enthalpy (V-L) [C] [MPa] [kg / m ³ ] [kg / m ³ ] [kJ / kg] -40 0.1183 586.5 2.796 421.336 -30 0.1784 574.3 4.103 410.22 -20 0.2596 561.7 5.837 398.35 -10 0.3661 548.7 8.088 385.66 0 0.5024 535 10.96 371.9 10 0.6734 520.5 14.6 356.9 20 0.884 505.2 19.16 340.6 30 1.139 488.8 24.86 322.4 40 1.445 470.9 32.03 302.1 50 1.807 451.2 41.11 279.1

In addition, the inventor tried to vary the composition of the components. In the present invention, when the weight ratio of propane is less than 70wt% or more than 90wt%, it did not show sufficient performance compared to the existing R-22.

And D.M.E. When it is out of the range of 3 ~ 8wt% and propylene 7 ~ 22wt%, it did not show sufficient performance compared to the existing R-22.

In the hydrocarbon-based mixed refrigerant of the present invention, in the practical application, refrigeration oil serving as a lubricant is added. Refrigerator oil may be used alone or in combination with standard products determined by the International Organization for Standardization. In particular, it is possible to use mineral oil mainly used in the existing refrigerator system, thus, glycol, ether-based oil can be used, and alkylbenzene can also be used.

If necessary, additives such as a load additive, a chlorine trapping agent, an antioxidant, an antifoaming agent, a dispersion cleaner, a viscosity index improver, an oily agent, an antiwear additive, an extreme pressure agent, a waterproofing agent, a corrosion inhibitor, a pour point enhancer, and a metal inert agent may be added. Can be.

This provides an environmentally friendly and thermodynamically compatible one without alteration of existing refrigeration systems.

Claims (1)

A hydrocarbon-based mixed refrigerant composition for a refrigeration system, containing 70 to 90 wt% of propane (C ₃ H ₈ ), 3 to 8 wt% of DME ((CH ₃ ) ₂ O), and 7 to 22 wt% of propylene (C ₃ H ₆ ). A hydrocarbon-based mixed refrigerant composition for a refrigeration system, characterized in that.