JPS59108807A - Power generating engine - Google Patents

Abstract

PURPOSE:In a power generating engine for collecting exhaust gas, to prevent cavitation by temporarily reducing refrigerant flow if the temperature falling speed of refrigerant is higher than predetermined level thereafter increasing gradually. CONSTITUTION:Temperature of refrigerant is detected by a sensor 10 while temperature varying speed is obtained at an operating section 11 and if it is higher than setting level, a flow regulating means 9 is operated through a signal generating section 12 to reduce refrigerant flow from a refrigerant carrying means 8 to a condenser 2 temporarily thereafter increase gradually. Through this operation, temperature falling speed of gas refrigerant flowing from an expander 1 into condenser 2 will never be extremely slower than condensation temperature falling speed to prevent temporal overcooling of condenser 2 thus to prevent cavitation in condensed liquid pump 3 for gas refrigerant.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a power generating engine, and particularly to a power generating engine suitable for recovering power from alternative energy such as solar heat, geothermal heat, and waste heat.

[Prior art]

In a conventional power generating engine, when the temperature of the cooling medium flowing into the condenser decreases and the rate of decrease is large, 1. Alternatively, when the temperature is constant and the flow rate increases and the increase is 7il]'4 degrees, cavitation of the liquid bubble occurs through the process described below.

■ Rapid decrease in coolant temperature (increase in coolant flow rate)
.

■ Rapid decrease in the temperature of the working medium in the solution.

■ Rapid decrease in condensing pressure.

(2) The rate of decrease in the gas medium temperature on the condenser inlet side is slower than the rate of decrease in the condensing temperature, and the degree of superheating on the condenser inlet side increases.

■ Decreased subcooling of the outlet medium (decreased condensing pressure and increased superheat).

■ Occurrence of cavitation.

This cavitation phenomenon significantly shortened the life of liquid pumps.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a power generating engine that eliminates the above-mentioned drawbacks and can prevent cavitation even when the coolant temperature suddenly drops or the coolant flow rate increases rapidly.

[Summary of the invention]

In the present invention, the cooling medium is provided with a flow rate adjusting means, the cooling medium temperature is detected, and when the temperature decreases and the rate of decrease is greater than a certain set value, the cooling medium flow rate is temporarily decreased, and then It is characterized by gradually increasing the flow rate.

[Embodiments of the invention]

Examples of the present invention will be described below.

FIG. 1 shows the first embodiment, in which the expander 1° condenser 2. Liquid pump 3. Steam generator 4. Eltl force conversion means 5
．． Load 6. Cylindrical medium conveying means 7. In the power generating engine υ such as the cooling medium conveying means 8, the cooling medium flows into the flow path! Adjustment means 9, cooling medium flow rate detection means 10, cooling medium temperature change rate calculation section 11. A signal generator 12 is provided. Next, FIG. 2 shows a second embodiment. This has a cooling medium flow rate detecting means 13 and a cooling medium flow rate change rate calculating section 14 connected to a signal generating section 12. Furthermore, as a third embodiment, a pressure detecting means 15 is provided in the low pressure section from the outlet side of the expander 1 to the inlet of the liquid pump 3, and the pressure change rate calculation 816 is connected to the signal generating section 12 (a third embodiment). 3
Finally, there is a fourth embodiment in which a temperature detection means 17 is provided in the Wm generator, and the temperature change rate calculation section 18 is connected to the signal generation section 12 (FIG. 4). Furthermore, the fifth
It is also conceivable to provide the flow node means 9 on a bypass path of the medium conveyance means 8 as shown in the figure.

Next, the operation of the first embodiment will be explained using FIG.

First, the coolant temperature is detected, and the temperature change rate is determined. If the temperature decrease rate is greater than a certain set value, the coolant flow rate is decreased, and then the flow rate is increased for maintenance. FIG. 7 shows the change in the coolant flow rate at this time. By performing the above operations, the rate of decrease in the gas medium temperature on the condenser inlet side will not be extremely slow compared to the rate of decrease in the condensing temperature, thereby preventing a temporary decrease in the degree of supercooling in the condenser. Therefore, cavitation can be prevented from occurring.

If the temperature change of the cooling medium is small but the flow rate is likely to fluctuate, the second embodiment is adopted, and as shown in Fig. 8, the rate of increase in the flow rate is detected and the setting is made at a certain speed. When the value is greater than or equal to the value, it is preferable to perform the same operation as shown in FIG. However, at this time, the coolant flow t is reduced to the previous flow rate and then gradually increased.

In addition, in the case of the third embodiment or the fourth embodiment, as shown in FIG.
Perform the same operation as shown in the figure.

In addition, after reducing the coolant flow rate as shown in Figure 10, the rate of decrease in temperature or pressure detected in Figures 6 and 9 is detected, and after the rate falls below a certain set value, It is also conceivable to gradually increase the coolant flow rate. FIG. 11 shows the change in the coolant flow rate at this time.

In addition, in the embodiments described so far, the flow # is adjusted in the cooling medium flow path:
Although the stage 9 is provided, the cooling medium may be controlled by changing the rotation speed of the cooling medium conveying means 8.

〔Effect of the invention〕

As shown above, according to the present invention, cavitation in the liquid pump can be prevented even when the coolant temperature suddenly drops.

[Brief explanation of the drawing]

FIG. 1 is a system diagram of the first embodiment, FIGS. 2 to 4 are diagrams showing narrow parts of other embodiments, and FIG. 5 is a diagram showing another method of installing the flow rate regulating means. Fig. 6 is the operation flow of the first embodiment, Fig. 7 is a time change chart of the coolant flow rate corresponding to Fig. 6, Fig. 8 is the operation flow of the second embodiment, and Fig. 9 is the operation flow of the third and third embodiments. The operation flow of the fourth embodiment, FIG. 10 is an operation flow that can be added to the operation flow of the first, third and fourth embodiments, and FIG. 11 is a cooling medium flow rate corresponding to the operation flow of FIG. 10. FIG. 1... Expander, 2... Condenser, 3... Liquid pump,
4... Steam generator, 8... Cooling medium conveying means, 9...
...Flow rate adjustment means. ¥Jl Figure 2 Figure ¥] 5 Figure 6 Figure 9 Figure 10 Figure kfJII Figure fl 710

Claims (1)

[Claims] 1. Expander, condenser, liquid pump, steam generator. A power source consisting of means for converting the power obtained in the expander into other types of power, a load that absorbs the power, a high temperature medium conveying means for conveying a high temperature medium to the steam generator, and a cooling medium conveying means for conveying a cooling medium to the condenser. A power generating engine characterized in that the generating engine is provided with a cooling medium flow rate adjusting means. 2 Detecting the cooling medium temperature, and when the temperature decreases and the rate of decrease is greater than a certain set value, the cooling medium m
2. The power generating engine according to claim 1, wherein the flow rate is decreased once and then the flow rate is gradually increased. 3. The low pressure side pressure is detected, and if the pressure decreases and the rate of decrease is greater than a certain set value, the coolant flow rate is temporarily decreased, and then the #L amount is continuously increased. A power generating engine according to claim 1. 4, #: The temperature of the condensed liquid is detected, and if the temperature decreases and the rate of fall is greater than a certain set value, the flow rate of the cooling medium is temporarily decreased, and then the flow rate is gradually increased. A power generating engine according to claim 1, characterized in that: 5. The coolant flow rate is detected, and if the flow rate increases and the rate of increase is greater than a certain set value, the coolant flow cover is temporarily reduced, and then the flow rate is gradually increased. A power generating engine according to claim 1.