Non-azeotropic fluid mixure for air conditioning devices

Abstract

A non-azeotropic fluid mixture for air conditioning apparatus characterized because the mixture comprises the following refrigerant fluids (gases) in given proportions: 2-Methylpropane (Isobutane) CH(CH3)3 (R-600a), Pentafluoroethane (R-125), Tetrafluoroethane (R-134a) Difluoromethane (R-32). The composition of the mixture contains at least one polymerization inhibitor agent (hydroquinone, benzotriazole, dimethyl-t-butylphenol).

Claims

1. A non-azeotropic fluid mixture for air conditioning devices, comprising: a mixture of the following gases: 0.5%-5% 2-Methylpropane (Isobutane) CH(CH.sub.3).sub.3, commercially known as (R-600a), 1%-3% Pentafluoroethane, commercially known as (R-125), 93%-95% 1,1,1,2-Tetrafluoroethane, commercially known as (R-134a), and 2%-3% Difluoromethane, commercially known as (R-32), wherein the mixture of gases further comprises 0.03-3 parts in weight of a polymerisation inhibitor for each 100 parts of the mixture of gases, and wherein the non-azeotropic fluid mixture is not miscible with mineral oils and it is used with polyester oils.

2. The non-azeotropic fluid mixture as set forth in claim 1, wherein the polymerisation inhibitor is principally hydroquinone, benzotriazole or dimethyl-t-butylphenol.

3. The non-azeotropic fluid mixture as set forth in claim 1, wherein the energy classification of the mixture obtained by these means as refrigerant fluid is A+++.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is an enthalpy-entropy chart, also known as the h-chart or Mollier diagram. The displayed chart covers a pressure range of 0.09-91.42 bar, and an enthalpy measured in (kj/kg) up to 500

DETAILED DESCRIPTION OF THE INVENTION

Description of the Preferred Embodiment

(2) The invention proposed refers to a non-azeotropic fluid mixture for air conditioning devices, a fluid mixture employed in such apparatus as a means to cool them.

(3) The cyclic performance of the composition in the invention is enhanced compared with conventional refrigerants available and, in synthesis, comprises the following gases in the proportions indicated: 0.5-5% 2-Methylpropane (Isobutane) CH(CH3)3, commercially known as (R-600a), 1%-10% Pentafluoroethane, commercially known as (R-125) 75%-95% Tetrafluoroethane, commercially known as (R-134a), 2%-20% Difluoromethane commercially known as (R-32), 0.03-3 parts of weight of polymerization inhibitor for every 100 parts of the previous mixture

(4) The main polymerization inhibitor agents are hydroquinone, benzotriazole or dimethyl-t-butylphenol.

(5) The mixture obtained by these means is a compound, chemically stable non-azeotropic ternary mixture with good thermodynamic properties, low environmental impact and very low toxicity.

(6) The mixture is classified as A1 group L1 of High Security refrigerants and with a temperature glide of 7.2° C.

(7) Because it is not miscible with mineral oils, it must be used with polyester oils (POE).

(8) To avoid fractionation, it must be loaded during the liquid phase.

(9) The mixture toxicity is very low, even after exposure. The AEL value (Allowable Exposure Limit) is 1000 ppm. (8 hours TWA).

(10) The following table shows a result of its Physical Properties.

(11) TABLE-US-00003 PHYSICAL PROPERTIES Molecular point (g/mol) 93.4 Boiling temperature (at 1.013 bar) (° C.) −30.8 Freezing point (° C.) −102 Critical temperature (° C.) 100.3 Critical pressure (abs bar) Critical density (kg/m3) 514 Liquid density (25° C.) (kg/m3) 1180 Liquid density (−25° C.) (kg/m3) 1307 Saturated vapour density (kg/m3) 4.9 Vapour pressure (25° C.) (bar 7.3 abs) Vapour pressure (−25° C.) (bar 2.4 abs) Boiling point vaporisation heat (kj/kg) 223 Specific liquid heat (25° C.) (1.013 bar) (kj/kg 1.48 k) Specific vapour heat (25° C.) (1.013 bar) (kj/kg 0.84 k) Thermal conductibility of the liquid (25° C.) (W/mk) 0.085 Thermal conductibility of the vapour (1 atm.) (W/mk) 0.0138 Liquid viscosity (25° C.) (cP) 0.204 Surface pressure (25° C.) (mN/m) 8.04 Solubility with water (25° C. at 1.013 bar) (wt %) 0.15 Refrigerant volumetric capacity (25° C.) (kg/m3) 1196.45 Inflammability limit in air at 1 atm. (% vol) none Toxicity (AEL) (ppm) 1000 PCA (GWP) — 1263 ODP — 0 sEER A+++ 15.38

(12) The mixture obtained by these means as refrigerant fluid will be used in both domestic and industrial air conditioning equipment, and in automobiles and also as refrigeration, and has an energy classification of A+++.

(13) This is a mixture whose refrigerant composition does not damage the ozone layer, has little global warming effect, very low inflammability, very low toxicity and which is very energy-efficient.

(14) Having sufficiently described the nature of the invention and how to put it into practice, it must be recorded that the foregoing specifications, also shown in the attached drawings, may be modified in detail provided that this does not, alter their fundamental principles established in the previous paragraphs and summarised in the following claims.