JPH0559907A - Absorbed liquid cooler - Google Patents

Abstract

PURPOSE:To reduce a concentration of non-condensed low boiling point component gas staying in a condenser so as to enhance heat conducting performance of the condenser in a low boiling point medium system by cooling liquid having a low boiling point component concentration in a cooler, introducing it toward an operating fluid outlet of the condenser, and absorbing non-vaporized low boiling point component gas. CONSTITUTION:Steam of operating fluid generated in an evaporator 2 is supplied to a turbine 4 for work, and then, its heat is absorbed by cooling water in a condenser 6, to be condensed. Steam residual liquid separated from the steam, i.e., the operating fluid which cannot be vaporized completely is supplied to a drain pot 14 through a liquid return pipeline 18 via a cooler 16. Liquid staying in an outlet of the evaporator has the lowest concentration of a low boiling point component inside a system. Meanwhile, a concentration of low boiling point component gas is remarkably high in the outlet of the condenser 6. Consequently, the low boiling point component gas is absorbed by the vaporized residual liquid supplied to the absorber 16.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a low boiling point medium system such as a heat pump or a binary cycle and is intended to improve the performance when a binary mixed medium is used as a working fluid.

[0002]

2. Description of the Related Art A binary power generation system shown in FIG. 3 will be described as an example of a low boiling point medium system. An evaporator 2, a turbine 4, a condenser 6 and a medium pump 8 are connected in series to form a closed loop 10. There is. Then, the working fluid circulating in the closed loop 10 first removes heat from the heat source fluid in the evaporator 2 to be evaporated, and the generated steam is supplied to the turbine 4. This steam expands in the turbine 4 and works to drive the generator 12. The steam discharged from the turbine 4 is deprived of heat by the cooling water in the condenser 6 and condensed.
The condensate is sent to the evaporator 2 again by the circulation pump 8.

By the way, in such a heat cycle such as a binary cycle or a heat pump, a Lorentz cycle may be constituted by using a non-azeotropic mixed medium as a working fluid in order to improve efficiency. For example, the binary cycle is basically a Rankine cycle, and when the working fluid is a single medium, as shown in FIG.
-Indicates isothermal changes. However, Freon R
When a mixed medium such as a mixture of 123 and R22 is used as a working fluid, the saturation temperature changes, the evaporation temperature rises in the evaporator 2 and the condensation temperature decreases in the condenser 6, as shown in FIG. .. This creates a Lorentz cycle and improves system efficiency.

FIG. 6 shows the simplest temperature-composition relationship of a two-component liquid-vapor system with the horizontal axis representing the mole fraction of the low-boiling component. G and L have a single phase, a gas phase and a liquid phase, respectively, and a region L + G is a two-phase region where liquid and vapor coexist. If the temperature of a liquid mixture of 60 mol% of low boiling components (molar fraction = 0.60) is raised under constant pressure, the change of this system can be considered along the straight line ab'cd "e.
Only liquid phase exists at low temperature, but vapor phase appears at point b '. The composition of this vapor phase is given by point b ", and the two conjugated phases are connected by the equilibrium connecting line b" b 'in the figure. Increasing the temperature will produce more steam, but in that case,
Due to the high concentration of low boiling components in the vapor, this component is relatively reduced in the liquid phase, the composition of the liquid changes along b'c'd ', while the composition of the vapor is b "c" At temperature t ° C, the total composition of the system in the two-phase region is represented by point c, but the vapor composition and liquid composition are both ends of the equilibrium connection line passing through point c, c " Given by points and c'points. The relative quantities of the two phases are derived from the lever principle of physics. In other words, the ratio of the number of moles of vapor and liquid is expressed by the ratio of the length of cc 'and the length of c "c.
At the point, the liquid phase almost disappears, and when the temperature becomes higher than this, the liquid phase disappears and only the vapor phase (d "point) remains. Even if the temperature is further raised (along d" e) Does not happen.

[0005]

In the vapor phase of the working fluid at the outlet of the condenser, the concentration of the low boiling point component is the highest in the system, and the gas with the low boiling point component stays near the condensation heat transfer surface. Therefore, in FIG.
As shown in (3), the low-boiling component exists in the condenser in the same manner as the non-condensable gas that impedes the mass transfer and the heat transfer, and reduces the heat transfer performance.

Therefore, the object of the present invention is to
In a low boiling point medium system using a binary mixed medium as a working fluid, it is to reduce the concentration of uncondensed low boiling point component gas in a condenser and to achieve the same effect as eliminating noncondensable gas.

[0007]

SUMMARY OF THE INVENTION The present invention is directed to a liquid having a low low boiling point component concentration cooled by a cooler and then led to a working fluid outlet side of a condenser to absorb unvaporized low boiling point component gas. Solved. As the cooling heat source of the cooler, cold water,
Atmosphere, low-temperature liquid medium, etc. are considered.

[0008]

[Function] By absorbing the uncondensed low-boiling component gas in the liquid having a low low-boiling component concentration, the uncondensed low-boiling component concentration near the outlet of the condenser is lowered, so that mass transfer and heat transfer are facilitated and the condenser transfer Thermal performance is improved.

In the case of absorption, latent heat of condensation is generated when the gas is liquefied, and the generated heat raises the liquid temperature and raises the pressure relative to the saturation temperature. However, the rise in pressure due to this temperature rise is prevented. For cooling, the cooler serves to lower the temperature of the absorbing liquid (dilute liquid). This promotes the absorption effect.

[0010]

EXAMPLE The case of application to the above-mentioned binary power generation system shown in FIG. 3 will be described as an example. In the example shown in FIG. 1, the evaporation residual liquid is used as the liquid having a low low boiling point component concentration. That is, the working fluid outlet side of the evaporator 2 is connected to the vapor phase of the drain pot 14 for separating uncondensed gas provided on the working fluid outlet side of the condenser 6 by the liquid return pipe 18. The liquid phase below the drain pot 14 is connected to the circulation pump 8. A cooler 16 is installed in the middle of the liquid return pipe 18. In the case of this embodiment, the working fluid liquid sent from the circulation pump 8 to the evaporator 2 is used as the cooling heat source of the cooler 16.

The steam of the working fluid generated in the evaporator 2 is supplied to the turbine 4 to perform work, and then the condenser 6 removes heat from the cooling water to condense it (). The evaporation residual liquid separated from the vapor, that is, the working fluid that has not been completely evaporated is sent to the drain pot 14 via the liquid return pipe 18 via the cooler 16. In this case, the low boiling point component concentrations of the evaporator 2 and the condenser 6 are as shown in FIG. The circled numbers in the figure indicate the following items. Condenser outlet liquid, evaporator inlet liquid,
Evaporator outlet liquid, evaporator outlet gas, condenser inlet (or overall average) gas, condenser outlet gas. As can be seen from FIG. 2, the evaporator outlet liquid exhibits the lowest low boiling component concentration in the system. On the other hand, at the outlet of the condenser 6, the concentration of the low boiling point component gas in the state indicated by is very high. Therefore, the low boiling point component gas is absorbed by the evaporation residual liquid sent to the absorber 16. Although there are gases in various states of ~ in the condenser, the gas in the state with the highest low boiling point component concentration is selectively absorbed. In this way, by sending the evaporation residual liquid at the evaporator outlet having the lowest low boiling component concentration to the condenser outlet side, the low boiling component gas is absorbed in this evaporation residual liquid, and as a result, the uncondensed low The boiling component gas concentration is reduced, and the heat transfer performance of the condenser is improved.

[0012]

As described above, according to the present invention, in a low boiling point medium system using a binary mixture medium as a working fluid, a liquid having a low low boiling point component concentration is cooled by a cooler and then the condenser is cooled. Since it is introduced to the working fluid outlet side to absorb the unvaporized low boiling point component gas, the low boiling point component gas is absorbed in the liquid with a low concentration of the low boiling point component and the uncondensed low boiling point component near the condenser outlet is absorbed. The gas concentration is reduced and the heat transfer performance of the condenser is improved. Further, since the absorption liquid is cooled by the cooler, the liquid temperature is not raised, and therefore, the intended purpose can be efficiently achieved without the adverse effect of the pressure rise.

[Brief description of drawings]

FIG. 1 is a flow sheet of a binary power generation system showing an embodiment of the present invention.

FIG. 2 is a vapor-liquid equilibrium diagram of a working fluid in the binary power generation system of FIG.

FIG. 3 is a flow sheet of a binary power generation system showing a conventional example.

FIG. 4 is a TS diagram of a Rankine cycle.

FIG. 5 is a TS diagram of a Lorentz cycle.

FIG. 6 is a vapor-liquid equilibrium diagram showing a temperature-composition relationship of a binary mixed medium.

FIG. 7 is a cross-sectional view of a condensation heat transfer surface.

[Explanation of symbols]

 2 Evaporator 4 Turbine 6 Condenser 8 Circulating pump 10 Closed loop 12 Generator 14 Drain pot 16 Cooler 18 Liquid return pipe

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Hiroyuki Sumitomo 3-4-6 Hiranocho, Chuo-ku, Osaka City, Osaka Prefecture HISAKA MFG. Co., Ltd. (72) Inventor Tsukio Yamazaki Hirano-cho, Chuo-ku, Osaka City, Osaka 3-4 No. 6 in Hisaka Manufacturing Co., Ltd.

Claims (1)

[Claims] 1. A low boiling point medium system using a binary mixed medium as a working fluid, wherein a liquid having a low low boiling point component concentration is cooled by a cooler and then introduced to the working fluid outlet side of a condenser, and is not evaporated. An absorption liquid cooler characterized by absorbing a low boiling point component gas.