JPS60173082A - Operating medium for heat pump - Google Patents

Abstract

PURPOSE:To provide an operating medium for a heat pump contg. specified compds. as essential constituents, which improves operating efficiency of the heat pump as compared with those employing conventional heating media and markedly increases heating and cooling capacity per suction air flow of compressor. CONSTITUTION:The operating medium contains dichloromonofluoromethane, monochlorodifluoromethane and monochloropentafluoroethane as essential constituents. It improves heating capacity and operating efficiency of a heat pump without excessive increase in pressure of condensation. It also increases heating and cooling capacity per suction air flow of a compressor to a marked extent and is of great practical use.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel working medium that can be used in heat pumps and the like.

In the present invention, the term "heat pump" refers not only to heat pumps in a narrow sense that produce high-temperature fluids, but also to heat pumps in a broad sense, including refrigerators and the like that produce cold fluids.

Heat pumps have a wide range of applications, including freezers, refrigerators, air conditioning equipment, heating equipment, hot water supply equipment, and equipment for waste heat recovery. From the standpoint of energy conservation, it is expected that the efficiency of heat pumps will be improved through the development of new working media. In other words, when utilizing heat, it improves the coefficient of performance, which is the ratio between the heating and cooling capacity and the electrical energy required for its operation, and also improves the capacity (heating and cooling capacity) per compressor suction volume of working medium. The development of a cutting-off working medium is desired. Furthermore, when heat pumps are applied to heat utilization equipment, there is a condition that the cost is lower than other methods, and as a working medium, there is no advantage to using it if it is rare and expensive, and it is limited to those that are cheap and easily available.

The present inventors have conducted various studies to meet such demands, and as a result, dichloromonofluoromethane (Freon-21
), monochlorodifluoromethane (Freon-22), and monochloropentafluoroethane (Freon-115) have been found to have superior properties compared to a single substance before mixing. In particular, a mixture of Freon-21 and a mixture of 48.8% by weight of Freon-22 and 51.2% by weight of Freon-115 (hereinafter referred to as Freon-502) is an excellent working medium for heat pumps. It was discovered that it has certain characteristics.

The present invention will be explained in detail below.

FIG. 1 shows a flow sheet of a heat pump using the working medium of the present invention, where 1 is a compressor, 2 is a condenser,
3.3' is the load fluid piping.

4 is a pressure reducing device, 5 is an evaporator, and 8.8' is a heat source fluid piping.

In the heat pump system shown in FIG. 1, the working medium is compressed by a compressor 1 and then led to a condenser 2.
Inside, it is cooled and condensed by the load fluid introduced from the pipe 3. Meanwhile, the load fluid is heated inversely in the condenser 2 and the tube 3
' and then subjected to load heating. Next, the condensed working medium is depressurized by the pressure reducing device 4 and then led to the evaporator 5, where it is heated and evaporated by the heat source fluid introduced from the pipe 6 and discharged from the pipe 6', and then transferred to the compressor again. 1 and repeat the above cycle.

FIGS. 2 and 3 show the cycles of the working medium in the heat pump system shown in FIG. 1 on pressure-enthalpy diagrams.

When saturated vapor as a working medium is adiabatically compressed, a wet state is shown in Fig. 2, and a dry state is shown in Fig. 3.

The change in the working medium due to the compressor in Figure 1 is a change from 8 to 9 or from 13 to 14 in Figures 2 and 3, and the change in working medium due to the condenser is a change from 9 to 11 or from 14 to 17. The change in the working medium due to the pressure reduction device is 11.
A change in the working medium by the evaporator corresponds to a change from 12 or 17 to 18, and a change from 12 to 8 or 18 to 13, respectively.

The operating conditions for the heat pump system shown in FIG. 1 using the working medium of the present invention are that the suction temperature of the compressor (temperature numbered 8 or 13) is 5°C, and the temperature at the start of condensation of the working medium in the condenser (temperature numbered 9 or 13) is set at 5°C. 15) to 40℃, 7
The temperature was set at 0°C.

Table 1 shows the coefficient of performance, heating capacity per compressor suction volume (hereinafter simply referred to as heating capacity), and pressure of the working medium in the condenser in the above heat pump system using the working medium of the present invention, along with comparative examples. write down

As understood from Table 1, the mole fraction of Freon-21 is 0.
．． The coefficient of performance of the heat pump using the working medium of the present invention, which is 70 to 0.95, is CFC-21 and CFC-5.
The condensation start temperature at 40° C. is improved by 4% compared to the case where only Freon-21 is used, and by 17% compared to the case where Freon-502 is used alone. Furthermore, if the condensation start temperature is high, Freon-502
When used alone, the condensation pressure increases, making it difficult to use ordinary equipment, but when Freon-21 is added, the condensation pressure decreases, and the present invention with a mole fraction of Freon-21 of 0.70 Although the coefficient of performance of the working medium is almost the same as when Freon-21 is used alone, the heating capacity is improved by 40%. Furthermore, the working fluid of the present invention is characterized in that its thermal stability is improved compared to Freon-21 by adding 1J of Freon-22 or Freon-115, which has higher thermal stability than Freon-21, to Freon-21. There is.

In other words, the working medium of the present invention has characteristics that can improve the heating capacity per suction volume of the compressor and also improve the coefficient of performance in a heat pump using the working medium without extremely increasing the condensing pressure. It can be said. Furthermore, dichlorodifluoromethane, which has traditionally been used as a working medium for air conditioning and medium-temperature heat pumps, is the first
When operating under the same operating conditions as when the table was obtained, the condensation start temperature was 70°C and the condensation pressure was 19.3kg/
The coefficient of performance for CR& was 3.77, and it was found that when the working fluid of the present invention was used, the condensing pressure was lower and the highest coefficient of performance was improved by 23%.

As explained above, when the working medium of the present invention is applied to heat pumps in a broad sense, including heating and cooling, etc., the coefficient of performance is improved compared to heat pumps using conventional working mediums.
Furthermore, the heating and cooling capacity per unit of suction air volume of the compressor can be significantly increased, resulting in an extremely useful effect in practice.

Table 1 Treatment starting temperature 40°C Condensation start temperature 70°C

[Brief explanation of drawings]

Fig. f51 is a flow sheet of a heat pump for explaining one embodiment of the present invention, Figs.
It is a pressure-enthalpy diagram showing a cycle using a 1/Freon-502i combination system as a working medium. 2. Review 3) 4 En71 Nbi Engineering 7) v. Procedural Amendment July 1980 V, Director-General of the Special Fraud Agency, Mr. Kazuo Wakasugi 1, Indication of the Case 1982 Special Fraud Application No. 26948 2. Name of the invention Working medium for heat pumps 3. Relationship with the case of the person making the amendment Patent applicant address 2-1-2 Marunouchi, Chiyoda-ku, Tokyo Name (
OO4) Asahi Glass Co., Ltd. 4, A (Embedded spontaneous amendment 8, Number of inventions increased by amendment None 8, Contents of amendment (1) No. 8 Correct the value of (kcal/+a3) as follows: Before correction After correction 165 → 212 191 → 244 212 → 272 233 → 300 583 → 849 or more

Claims (1)

[Scope of Claims] 1. A working medium for a heat pump, characterized in that it contains dichloromonofluoromethane, monochlorodifluoromethane, and monochloropentafluoroethane as essential components. 2. The working medium according to claim 1, wherein the monochlorodifluoromethane and monochloropentafluoroethane have a co-liquid composition of 48.8% by weight of monochlorodifluoromethane and 51.2% by weight of monochloropentafluoroethane. 3. The molar fraction of dichloromonofluoromethane is 0.70
The working medium according to claim 1, wherein the working medium is 0.95 to 0.95.