JPS5912994A - Working fluid for rankine cycle - Google Patents

Abstract

PURPOSE:A novel working fluid for Rankine cycle having improved energy conversion efficiency, heat exchange characteristics, heat stability, etc., obtained by blending trichlorofluoromethane with difluoroethane. CONSTITUTION:The desired working fluid obtained by blending (A) usually 95- 50wt% trichlorofluoromethane with (B) usually 5-50wt% difluoroethane. A rotary or reciprocating volume type expansion device or a turbine expansion device is used as the expansion device 1 for Rankine cycle, a vapor generator of the same type as that of steam generator is used as the vapor generator 4, a condenser for refrigerator as the condenser 2, and a pump for transporting organic solvents by pressure for chemical devices as the pump 3.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel working fluid for cattle cow cycles.

The liquid medium is heated and evaporated using thermal energy and expanded in an expansion device to obtain a mechanical funnel.Then, this medium is condensed and pressurized by a pump to form a liquid medium.The cycle is repeated to generate heat. In the run cycle, which converts energy into mechanical machinery, water is almost the only medium that has traditionally been used as the medium or working fluid for the run cycle. Water as a working fluid has been used in steam engines for a long time. However, water has a high freezing point and a large vapor specific volume, which limits its range of use.Especially when using a low-temperature heat source, the disadvantage is that the equipment becomes bulky and efficiency decreases; There is a limit to the temperature at which it can be used because it sometimes freezes.

Many organic working fluids have been proposed to improve these drawbacks of water, but many are flammable or corrosive, and so far none can be used satisfactorily. Not obtained.

However, among these, the one that has been put into practical use is Triku-00 Fluo-0 Metasi (hereinafter referred to as Freon-11).
However, the working fluid for the Narorun cycle from Freon-11 has the drawback of low conversion efficiency from thermal energy to mechanical energy f-.

Since Flothy 11 has the above-mentioned drawbacks, it is expected that a working fluid with high energy conversion efficiency will emerge.

The inventors of the present invention have conducted a variety of research in response to such demands.While conventional working fluids have all been researched and used using a single substance, we have developed a mixed system in which materials with different properties are mixed. It was found that the mixture of trifluoro-D methane (hereinafter referred to as Freon-11) and difluoro-methane (hereinafter referred to as Freon-152) exhibited superior properties compared to other materials. It was discovered that this fluid has extremely excellent properties as a working fluid, leading to the completion of the present invention.

The working fluid for a mixed cycle of the Flossy 11 and Flossy 152 of the present invention has the following characteristics.

First, the Flocy cycle using a mixed system of Freon-11 and Freon-152 has a heat source energy conversion efficiency of Flothy 11, which is conventionally known as a working fluid for the Run+cy cycle.
It has sufficiently high properties compared to Flossy 114 and Flocy 114 (20%).

Second, Flossie 152 is flammable.

However, when mixed with Flossy 11, its combustibility decreases, and if the mixing ratio of Flossy 11 is 69 parts or higher, it will not burn at all. Also, the mixing ratio of Flossy 11 is 69-50
%, the flammability is very small and does not pose a major problem in practical use.

Particularly remarkable improvement in output efficiency can be obtained at a mixing ratio of 95 to 50% by weight of t7'c [1,y -11] and 5 to 50% by weight of Flossy 152.

Figure 1 is a pressure curve diagram (P-H diagram) of a mixture of 70 Sea 11 and Freon-152 of the present invention (mixing ratio 70%/30% by weight), and the point A1 drawn in the diagram is
B, C, and D%E correspond to each state point of the Rashi-in-cycle cycle illustrated in FIGS. 2 and 3 below of the Ushi-+-shi cycle carried out in the following example.

Figure 2 is a flow diagram for converting heat energy f- into mechanical energy f-, and Figure 3 is a flow cycle system diagram for converting heat energy f- into mechanical energy f-.
This figure shows an engine cycle using a mixture of No. 1 and Flossy No. 152 as the working fluid, plotted on a temperature graph. In addition, the symbols (A-E
) correspond to each state point indicated by symbols (A-E) in FIG.

The working fluid heated by the steam generator (4) evaporates, producing high-temperature, high-pressure steam. This state is shown in Figure 3 (D).
, (E), (, ()).During this time, the liquid working fluid is heated and its temperature rises, and boiling begins and the entire amount is vaporized.This working fluid vapor then enters the expansion device (1). Through adiabatic expansion, the temperature and pressure decrease, and work between (A) and (B) shown in Figure 3 is performed.Expansion device f4)
The working fluid, which has undergone work and has become low temperature and low pressure, then enters the condensing device (2) and is condensed and liquefied as shown by CB>-(C) in FIG. This liquefied working fluid is positive (
3), is pressurized, enters the steam generator (4) again, and the cycle as described above is repeated. In Figure 3, point (a) shows the state of the hot water when it enters the steam generator of the run cycle, and point (h) shows the state of the hot water when it enters the steam generator of the run cycle. The state of the hot water when it comes out is shown, and the arrow on the straight line drawn from point (α) to point (h) shows the direction of flow of hot water. In addition, point (d), (-1 indicates the state of the cooling water in the condenser, (d) indicates the state of the cooling water at the condenser inlet, (=) indicates the state of the cooling water at the condenser outlet, and (,
The straight arrow drawn from point (Z) to point (-) indicates the direction of the flow of cooling water.

As the expansion device used for the above-mentioned Rashishi cycle, a rotary or reciprocating positive displacement expander or a tarsi expander can be used, and as a steam generator, a boiler used to generate steam can be used. It is also possible to use the same type of condensing device, and the type used in refrigeration equipment can be used as the condensing device. As for the pump, a pressurized organic solvent pump generally used in chemical equipment can be used.

The rinsing cycle working fluid of the present invention can be used alone, but other additives can be added as needed. For example, Freon-152 is flammable and has a lower main boiling point than Flothy-11, so in the gas phase, Flothy-152
The higher the ratio, the higher the viscosity. Therefore, other Flossy gases such as Flossy 114, Flossy 0υ-12, Flossy 2
2 or Flossie 13B+ can be added to suppress viscosity. The addition amount is usually 50% by weight or less based on the amount of Freon-152.

Next, the present invention will be explained using Examples, Comparative Examples, and various tests π (1).The blending ratio of each component is % by weight.
Displayed with.

Examples 1 to 3 and Comparative Example 1 According to the engine cycle shown in FIGS. 1 to 3 above, mixtures of 0 sea 11 and Flo sea 152 of the present invention at various mixing ratios and Flo sea 114 were used as working fluids, respectively. This cycle was run on the same equipment. As for the operating conditions, the temperature of the hot water at point (α) in Figure 3 is 120°C, the temperature of the cooling water shown at point (d) is 25°C, and the thermal energy of the hot water is + 000 t/hour, 1,000 -. Determine the output characteristics when generating electricity using the obtained mechanical channel f-,
The results shown in Table 1 were obtained. Note that the evaporation temperature in this cycle is 80°C, and the condensation temperature is 42°C.

Table 1 Heat source temperature 120℃ 17th. ) From the results, □wa. 1, eh. , match.

In comparison, the improvement in output characteristics by the mixed system of FuO,:/-11 and Futa,7='152 is remarkable, and the improvement in output characteristics is remarkable.
An increase in output is observed when the mixing ratio is in the range of 5 to 50% by weight. Furthermore, in the mixed system of Flossy 114 and Flossy 152, the pressure difference between the evaporator and the condenser is small, and the pumping power is small, which is a feature that is difficult to achieve.

Next, the working fluids of Fluoro'J-11 alone and Freon-11/Furon-152 of the present invention (weight ratio 70/30) were sealed together with iron and lubricating oil in glass shielded tubes, and heated to 150°C. After heating for 100 hours, the halogen concentration of the working fluid in the shield tube and the number of decomposition products were measured using a gas chromatogram. The results are shown in Table 2.

Table 2 As shown in Table 2, compared to the working fluid of Flothy 11 alone, the mixed system of Flochy 11 and Flochy 152 of the present invention produces less halogen concentration at high temperatures, and according to the 71 gas chromatographic rough analysis. Fewer decomposition products are detected. In the case of a mixed system of Flocy 11/Freon-152,
Fewer halogens are produced under high temperatures, which means that metals in the equipment are less likely to corrode, and the fact that there are almost no decomposition products means that during use, there is an increase in decomposition products. This means that the thermodynamic properties of the working fluid are prevented from changing and the efficiency is prevented from decreasing.

As mentioned above, Freon-11 and Freon-152 of the present invention
The mixed system with CFC-11 is superior to conventional Freon-11 in many aspects such as energy conversion efficiency, heat exchange characteristics, and thermal stability, and can be used as an excellent working fluid for incineration cycles. can.

[Brief explanation of the drawing]

Fig. 1 is a pressure-digital diagram of the Freon-11/Fron-152 mixed system, which is the working fluid for the run cycle of the present invention, Fig. 2 is a system diagram of the flow + cycle, and Fig. 3 1 is a temperature-end zero diagram plot of a cylinder cycle using a fluorocarbon-11/fluorocarbon-152 mixed system as the working fluid. (Above) Figure 2 A i3 Zuko Nkuruhi 0 Procedural amendment (Rin) March 17, 1980 Commissioner of the Patent Office Kazuo Wakasugi 1, Indication of the case 1988 Patent Application No. 123440 2 Invention o Name: ,+y'JI, , Working fluid 3, Correction person 4, Agent 2-10 Heiwa Building, Higashi-ku, Osaka City Telephone: 06-203
-0941 (subject) Spontaneous 6, No number of inventions increased by amendment 7, 0 subject to amendment. , wa, medium ``A...-7''. Contents of the 4th amendment 1 "Viscosity" in lines 1+ to 12 of page 7 of the specification is corrected to "flammability." 2. "Viscosity" on page 7, line 14 of the specification is corrected to "flammability." 3 Correct Figure 3 as shown in the attached sheet. (that's all)

Claims (1)

[Claims] (1) A working fluid for a tank cycle, characterized in that trifluorofluoride and difluoroester are mixed. (2) The working fluid for a run+cycle according to claim 1, characterized in that 95 to 50 weights of Triku00 Fluoride and 5 to 50 weights of Difluoro Oetashi are mixed.