JPH0655939B2 - Mixed refrigerant - Google Patents

Description

TECHNICAL FIELD The present invention relates to a working medium for a vapor compression refrigeration cycle, which cools or heats a liquid by utilizing a state change of a substance such as pressurized liquefaction and depressurized vaporization. The present invention relates to a mixed refrigerant used, and more particularly, to a mixed refrigerant used for air conditioning equipment used for air conditioning.

[Prior Art] A vapor compression refrigeration cycle is widely applied to air conditioning equipment, refrigerators, hot water supply equipment, and the like, and is put to practical use.

As a working medium used in such a compression refrigeration cycle, various working media centered on a CFC-based refrigerant have been developed and put into practical use.

A typical example is a working medium containing a methane- or ethane-based halogenated hydrocarbon as a single component.
1, R12, R13, R14, R22 and the like, and in the ethane system, R113, R114, R115 and the like are used according to the purpose.

Among them, R22 (monochlorodifluoromethane) is widely used as a refrigerant for air conditioning equipment used for air conditioning. Compared to R12 (dichlorodifluoromethane) that is commonly used in refrigerators and dehumidifiers, R22 is
A compressor of the same size can obtain a large refrigerating capacity, so the device can be downsized. Also, the suction pressure is higher than the atmospheric pressure even at an evaporation temperature of -40 ° C, which is an advantage.
It is widely used as a refrigerant that is chemically stable and has good thermodynamic properties.

In addition, a non-azeotropic mixed refrigerant has recently been studied because of an attempt to supplement the characteristics that cannot be satisfied by a single refrigerant by mixing and using the refrigerants.
By mixing 3B1 (monobromotrifluoromethane), a heat pump cooling and heating device has been commercialized, which is devised to increase the heating capacity over R22 (Showa 6).
(See Denpa Shimbun, dated August 30, 0).

The above-mentioned mixed refrigerant has been developed with an emphasis on improving the heating capacity over the R22 single refrigerant, and the current status is that attention is not paid to the coefficient of performance (Academic Lecture Meeting of the 1979 Japan Refrigeration Association). (See pages 29-30 of the collection of lecture papers).

The inventors of the present invention mainly use R22 as a working medium of this type, and in contrast to this, 1,1,1-trifluoroethane (R
143a) is mixed (preferably R143a in the mixed refrigerant)
Is a mixed refrigerant having a molar fraction of 0.25 to 0.45)
It has been found that the condenser capacity and the coefficient of performance are improved as compared with the case of 22 alone.

[Problems to be Solved by the Invention] An object of the present invention is to use R22 as a main component and to add R143
(EN) It is intended to provide a mixed refrigerant for a heat pump cooling / heating machine, which has a larger heating capacity and a higher coefficient of performance than the mixed refrigerant in which a is mixed, and which can achieve miniaturization and high efficiency of a conventional air conditioner.

[Means for Solving the Problems] The inventors of the present invention have studied many chlorofluorocarbon-based refrigerants in order to achieve the above-described object of the present invention. And R143
It has been found to be achieved by a mixed refrigerant formed by mixing a (1,1,1-trifluoroethane) and R290 (propane).

EXAMPLES Next, the present invention will be described in detail with reference to the accompanying drawings, but the present invention is not limited to these examples without departing from the gist of the present invention.

FIG. 1 is an outline of a vapor compression refrigeration cycle in which the mixed refrigerant (working medium) of the present invention was tested.

(1) is a working medium compressor, (2) is a water-cooled double-tube condenser, (3) is a liquid receiver, (4) is a pressure reducing expansion valve, and (5).
Is an evaporator, (6) is a brine tank for heat absorption source, (7) is an accumulator, and (8) and (8 ') are piping for heat radiation source water.

In such a vapor compression refrigeration cycle, the working medium is compressed by the compressor (1) and then guided to the condenser (2) to give heat to the radiant heat source water to be condensed. In this example, the inlet and outlet temperatures of the heat radiation source water were made substantially constant, and the condenser capacity was calculated by the product of the inlet and outlet temperature difference, the flow rate, and the specific heat for comparison.

The condensed working medium is stored in the liquid receiver (3), regulated by the decompression expansion valve, then guided to the evaporator (5), and absorbs heat from the heat absorption source brine tank (6) to evaporate, The cycle of being sucked into the compressor (1) again via the accumulator (7) is repeated. The brine tank for the heat absorption source has a built-in heater for heating, which is configured so that the input power is controlled in proportion to the capacity of the evaporator and the temperature inside the tank is kept constant so that a comparative test can be performed. There is.

Table 1 shows the results of the vapor compression refrigeration cycle having the configuration shown in FIG.

As test conditions, when using the mixed refrigerant of the present invention and the refrigerant of R22 alone, the hot water temperature of the condenser inlet / outlet and the brine tank temperature for the heat absorbing source of the evaporator are made substantially constant, and
This is a comparison of the compressor input, the condenser capacity, and the coefficient of performance, with the refrigerant pressure at the inlet of the expansion valve for decompression and the refrigerant temperature at the inlet of the accumulator being substantially equal.

Examples 1 and 2 are results using the mixed refrigerant of the present invention,
A comparative example is the result of testing using the R22 refrigerant.

As is clear from the comparison of the condenser capacity and the coefficient of performance in Table 1, by using the mixed refrigerant of the present invention, the coefficient of performance is 7 to 8% and the condenser capacity is 12 to 16% as compared with the R22 refrigerant.
You can see that it will improve.

On the other hand, when a mixed refrigerant in which R143a is mixed with R22 (the molar fraction of R143a in the mixed refrigerant is 0.25 to 0.45) is used, the coefficient of performance improvement rate compared to R22 is at most 2.4%. As a result, the condenser capacity improvement rate is about 7%.

When focusing on the two components of R22 and R143a in the mixed refrigerant of the present invention, the mole fraction of R143a in the two components is 0.25 to 0.45, and the mole fraction of R290 in the three components to which R290 is added. The rate is preferably 0.05 to 0.25.

[Advantages of the Invention] The three-component mixed refrigerant of the present invention, which is a mixture of R143a, R290, and R22 as a working medium for a heat pump air conditioner that uses a vapor compression refrigeration cycle, is R22 which is widely used at present, or Compared with a mixed refrigerant formed by mixing R22 and R143a, not only the capacity of the condenser but also the coefficient of performance can be improved, and the heat pump air conditioner can be made smaller and more efficient.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view of a vapor compression refrigeration cycle using the mixed refrigerant (working medium) of the present invention. (1) ... Compressor of working medium, (2) ... Water-cooled double-tube condenser, (3) ... Liquid receiver, (4) ... Expansion valve for decompression, (5) ... Evaporator , (6) …… Brine tank for heat absorption source, (7) …… Akymulator, (8), (8 ′) …… Pipe for heat radiation source water.

Claims (1)

[Claims] 1. A mixed refrigerant containing monochlorodifluoromethane as a main component and 1,1,1-trifluoroethane and propane mixed therein.