JPH04110384A - Fluid for heat transfer - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to heat transfer fluids used in refrigerators, heat pumps, and the like.

In this specification, "%" means "% by weight".

BACKGROUND ART Conventionally, as heat carriers (refrigerants) for heat pumps, chlorofluorohydrocarbons, fluorohydrocarbons, azeotropic compositions thereof, and compositions in the vicinity thereof have been known. These are generally collectively referred to as fluorocarbons, and currently R-11 (trichloromonofluoromethane), R-22 (monochlorodifluoromethane), R-502 (R, -22+chloropentafluoroethane), etc. are mainly used. has been done.

However, in recent years, it has been pointed out that certain types of fluorocarbons, when released into the atmosphere, destroy the ozone layer in the stratosphere and, as a result, have a serious negative impact on the global ecosystem, including humans. Therefore, the use and production of fluorocarbons, which pose a high risk of ozone layer depletion, has been regulated by international agreements. CFCs that are subject to regulations include R-11 and R-12.
Furthermore, R-22 is not currently subject to regulation because it has a small effect on ozone layer depletion, but in the future it is hoped that a refrigerant with less effect will emerge. Regulations on the use and production of fluorocarbons, whose demand is increasing every year with the spread of refrigeration and air conditioning equipment, have an extremely large impact on the living environment and current social institutions in general. Therefore, there is an urgent need to develop a new heat medium (refrigerant) for heat pumps that has no or very low risk of causing ozone layer depletion.

Means for Solving the Problems The present inventor has developed a heat transfer fluid suitable for heat pumps or heat engines, which naturally has a small effect on the ozone layer even when released into the atmosphere. Various research efforts have been made to find new heat transfer fluids that have no adverse effects. As a result, they discovered that a group of organic compounds with a specific structure meet the requirements for the purpose.

That is, the present invention provides a heat transfer fluid having the following molecular formula: C3H,,F.

(However, m = 0 ~ 6. n = o ~ 6 and m + n = 6
) and is composed of an organic compound having a three-membered ring structure. ” The main physical properties of typical compounds used in the present invention are as follows.

■, CH2CH2cH2 (cyclopropane) boiling point
-33,0'C Critical temperature 119°C Critical pressure 57kg/c Kidney molecular weight 42. 08 n, CF2CF2 CFH (pentafluorocyclopropane) Boiling point -10,0'C Critical temperature 3°C Critical pressure 41. 0kg/cJ molecular weight
132.03 m, CF2 CH2CH2 (1,1-difluorocyclopropane) Boiling point -16,0'C Critical temperature -37°C Critical pressure 50.5 kg/c Ferment molecular weight
78.06 IV, CFHCFHCFH (1,2,3-trifluorocyclopropane) Boiling point -9,9°C Critical temperature 134°C Critical pressure 41.8 kg/c Wei molecular weight
96.05 The three-membered ring compound represented by C3H□Fn used as a heat medium in the present invention does not contain chlorine atoms and bromine atoms that affect the ozone layer, so there is no risk of causing the problem of ozone layer destruction. .

On the other hand, the three-membered ring compound represented by C3H,,F, has excellent properties as a heat medium for heat pumps, and has a well-balanced performance coefficient of performance, refrigeration capacity, condensing pressure, discharge temperature, etc. is taken. Furthermore, the boiling point of this compound is the currently widely used R-12,R-
22, because it is close to that of R-114 and R-502,
Under the conditions of use of these known heat carriers, i.e. evaporation temperature -20
to 10°C and condensing temperatures of 30 to 60°C.

Further, in the present invention, the present invention includes at least a three-membered ring compound represented by C3H, , F, and R-22(CH(l
F2 ), R-32 (CH2F2 ), R-124 (
CF3 CHCl2F), R-125 (CF3 CF2
H), R-1:34a (C3HFn), R-142b (C3H□Fn), R143a (CF3CH3) and R-152a (CHF2
A mixture containing at least one selected from the group consisting of CH3) may be used as the heating medium. By using these low boiling point refrigerants, it is possible to further improve the refrigerating capacity, and by mixing refrigerants with a large latent heat of vaporization, the coefficient of performance can be improved, or the solubility with refrigerating machine oil can be improved. benefits.

The three-membered ring compound represented by C3H0Fn or the three-membered ring compound represented by C3HmFo used in the present invention and R, -2
2, R-32, R-124, R-125, R-134a
, R-142b with at least one of R143a and R-152a has the general characteristics required for a heat medium for heat pumps (e.g., compatibility with lubricating oil, non-corrosion of materials, etc.) It has been confirmed that there are no problems with this.

Effects of the Invention The heat transfer fluid of the present invention achieves the following remarkable effects.

(1) Cycle performance equivalent to or higher than that of heat pumps that have conventionally used R-12, R-22, or R502 as a heat medium can be obtained.

(2) Because of its excellent performance as a heat medium, it is also advantageous in terms of equipment design.

(3) Even if the heat transfer medium were to be released into the atmosphere, there would be no risk of ozone layer depletion.

EXAMPLES Examples and comparative examples are shown below to further clarify the features of the present invention.

Example 1 Using C3H6 (cyclopropane) as a heat medium 1
In a horsepower heat pump, the evaporation temperature of the heat medium in the evaporator is -10°C2-5°C, 5°C and 10°C.
C, the condensation temperature in the condenser is 50°C, the degree of superheating and the degree of supercooling are 50C and 3°C, respectively,
I did the driving.

In addition, as comparative examples, R-12 (comparative example 1), R-22
(Comparative Example 2) and R-502 (Comparative Example 3) were used as working fluids, and the heat pump was operated under the same conditions as above.

From these results, the coefficient of performance (COP) and the refrigeration effect were determined using the following equations (see the Mollier diagram shown in FIG. 1).

COP = (hl h4)/(h2
ht) Refrigeration effect = hany4 hl... Enthalpy of heat medium at the evaporator outlet h2...
・Enthalpy h4 of the heat medium at the inlet of the condenser Enthalpy of the heat medium at the inlet of the evaporator The circuit diagram of the refrigeration cycle used in this example and the comparative example is shown in FIG.

The calculation results of COP and refrigerating capacity are shown in FIGS. 3 and 4, respectively, in comparison with the results of Comparative Examples 1 to B.

The coefficient of performance shown in Figure 3 is a measured value (COPB) at an evaporation temperature of 5°C when R-22 is used as a heat medium.
The value obtained by dividing the measured value (COPA) of each heat medium (
COPA /COPB). In particular, the numerical value of the heat transfer medium according to the present invention is indicated by "○".

In addition, the refrigerating capacity shown in Fig. 4 is a measured value (capacity B) at an evaporation temperature of 5°C when R-22 is used as a heat medium.
It is indicated by the numerical value (capacity A/capacity B) obtained by dividing the measured value (capacity A) of each heat medium. The numerical value of the heat medium according to the present invention is also indicated by "○".

As is clear from FIG. 3, the heat medium according to this example is c
Regarding op, it shows a value as good as R-12 and R22. Furthermore, as is clear from FIG. 4, the refrigeration effect shows an intermediate value between R-22 and R-22.

Further, Table 1 shows the comparison results of the condensing pressure and compressor discharge temperature at an evaporation temperature of 5°C.

Table 1 Condensation pressure (kg/crI-A) Discharge temperature (℃') Example 1 Comparative example 1 Comparative example 2 Comparative example 3 The condensation pressure and discharge temperature of the heat medium according to this example are R
-22, which is advantageous in terms of equipment design.

From the above results, when using a three-membered ring compound represented by C:l',,'H6 as a heat medium, heat pumps using R-12, R-22, and R502, which have been widely used in the past, can be used. It is clear that the present invention is advantageous from the viewpoint of equipment design.

Example 2 A heat pump was operated in the same manner as in Example 1 except that CF2CH2CH2 (pentafluorocyclopropane) was used as the heat medium and the evaporation temperature of the heat medium in the evaporator was set to 5°C.

The coefficient of performance and freezing capacity are shown in Table 2 below.

Both values are the values obtained by dividing the measured value (COPA and capacity A) of the heat transfer medium of this example by the measured value (cap and capacity B) of the evaporation temperature at 5°C when R-22 is used as the heat transfer medium. is shown.

Table 2 Example 2 R-12R-502 COPA/C0PB 1.021.02 0.92 Capacity A/Capacity, 0.36 0.61
1.03 Example 3 A heat pump was operated in the same manner as in Example 1 except that CF2CH2CH2 (1,1-difluorocyclopropane) was used as the heat medium and the evaporation temperature of the heat medium in the evaporator was set to 5°C. I did this.

The coefficient of performance and freezing capacity are shown in Table 3 below.

Both values are calculated by dividing the measured value (COPA and capacity A) of the heat transfer medium of this example by the measured value (COPB and capacity B) of the evaporation temperature when R-22 is used as the heat transfer medium at 5°C. This is an indication.

Table 3 Example 3 R-12R-502 COPA/C0PB 1.061.02 0.92 Capacity A/Capacity B O,450,611,03 Example 4 CFHCFHCFH (1,23-trifluorocyclopropane ), and the heat pump was operated in the same manner as in Example 1, except that the evaporation temperature of the heat medium in the evaporator was 5°C.

The coefficient of performance and freezing capacity are shown in Table 4 below.

Both values are calculated by dividing the measured value (COPA and capacity A) of the heat transfer medium of this example by the measured value (COPB and capacity B) of the evaporation temperature when R-22 is used as the heat transfer medium at 5°C. This is an indication.

Table 4 Example 4 R-12R-502 COPA/C0PB 1.061.02 0.92 Capacity A/Capacity B 0.37 0.61
'1.03

[Brief explanation of the drawing]

FIG. 1 is a Mollier diagram used to determine the coefficient of performance (COP) and refrigeration effect in the examples. FIG. 2 is a circuit diagram of a refrigeration cycle used in this example and a comparative example. FIG. 3 is a graph showing cops according to Example 1 and Comparative Examples 1 to 3. FIG. 4 is a graph showing the refrigerating capacity of Example 1 and Comparative Examples 1 to 3. (hereinafter ``2) 1.

Claims (1)

[Claims] 1. A heat transfer fluid made of an organic compound having a molecular formula of C_3H_mF_n (where m=0 to 6, n=0 to 6, and m+n=6) and having a three-membered ring structure.