JPS5848706A - Rankine cycle device - Google Patents

Abstract

PURPOSE:To eliminate overexpansion loss and improve operation efficiency by providing a bypass circuit communicating a position immediately before an operating medium completes its expansion in an expander with an introduction side of the operating medium of a condenser. CONSTITUTION:An operating medium is sucked up into a cylinder chamber 17 through a suction port 16. A bypass inlet hole 21 is provided at the position of the cylinder chamber 17 between vanes 18a' and 18b', that is, at the position immediately before the expansion process is completed. At a part of an exhaust port 20, is provided a bypass outlet port 22, which is communicated with the bypass inlet hole 21 through a communication path 23. A check valve 24 is provided at the intermediate part of the communicating path 23. When the condensing pressure is higher than a predetermined pressure, the check valve 24 is opened, and hence both pressures become the same and no genration of the rotating force in the reverse direction occurs. In this manner, the overexpansion can be suppressed and the driving efficiency can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a Rankine cycle device with an improved power output structure.

This type of Rankine cycle device has conventionally been constructed as shown in FIG. In other words, 1 is an expander, 2 is a condenser, and 3 is a circulation pump! , 4 are steam generators, and these are communicated through a pipe P. A heating element 5 is disposed near the steam generator 4, for example, at the end of a gas burner. The working medium guided to the expander 1 is heated by the heating element 5 when passing through the steam generator 4, and is in a high-pressure vaporized state. The working medium is then expanded in the expander 1 to provide power to the compressor of the refrigeration cycle (not shown), and the expanded working medium is transferred to the condenser 1.
It condenses and liquefies. Further, by the operation of the circulation l/n f3, the steam is sent to the steam generator 4 and heated again.

The expander 1 is constructed as shown in FIG. 2, and the working medium led from the circulation tank f1 is sucked into the cylinder chamber 1 through the suction port body. The cylinder chamber 1 accommodates a nine-eccentric rotor t, which is provided with vanes 81 to 14 made of a plurality of materials at predetermined intervals and capable of protruding. , this rotor is connected to the cylinder chamber 1 from the suction port body 6 to the discharge port body 10.
are rotated eccentrically, and each vane 1a and ttb, ab and 1., 1
- Expand the working medium led between aa and aa, and between aa and 8a, respectively. As a result, force is applied to each of the vanes 11 to #4 to generate rotational force in the rotor 9.

By the way, in the figure, the spatial pressure between vane 1a and vane 8b indicated by the solid line is equal to the pressure of the steam generator 4, and the spatial pressure between vane a a' and vane j b' indicated by the two-dot chain line is equal to the pressure of the steam generator 4. It is desirable that the pressure in the condenser 2 is equal to the pressure in the condenser 2. That is, as can be explained from FIG. Then, the output of the rotor 9 can be expressed as the area surrounded by the A-11-Co-Do diagram.

However, for example, if the suction pressure of the circulating I ring J becomes weaker or the load on the condenser 2 increases, the condenser 2
The pressure of the specified pressure may also be higher than the specified pressure. In other words, the parts 78a' and 71b immediately before the completion of the expansion process.
This is the case when the space pressure between ′ and ′ is lower than the condensation pressure.

If the condensation pressure at this time is y, it intersects with the pressure P' at point 0 while the medium supplied to the expander 1 at M-B expands to B-C@ after the supply is closed. Therefore, from point O, the condensing pressure P' is also lower than p.The preceding vane (for example, 8b') applies a rotational force in the opposite direction to the point #.

This O output is expressed as the area surrounded by ao-c'-c, and the output is obtained by subtracting it from the area surrounded by mu-B-0-D', which is the original output. For example, the Co area is called an overexpansion loss, so if the condensation pressure increases even slightly, there is a disadvantage that the overexpansion loss of the expander 1 becomes significant.

The present invention has been made in view of the above-mentioned circumstances, and its purpose is to locate the position immediately before the expansion of the working medium in the expander and the introduction side of the condenser when the condensation pressure increases. By providing a bypass i-way for communicating with the above, the present invention aims to provide a Rankine cycle device that eliminates overexpansion loss and improves operating efficiency.

An embodiment of the present invention will be described below with reference to drawing 4. Since the Rankine cycle itself is constructed as shown in Figure 1 of the collection, the explanation will be omitted.

However, the main parts of the expander 1 are constructed as shown in FIG.
e I J b e 1 l @ e I Jl d
The vane s19 is a rotor, and the vane 20 is a discharge port body. Also, the vane J a m'tobe 718b in the figure
A bypass introduction hole 21 is provided at a position facing the cylinder chamber 11 between the cylinder chamber 11 and the cylinder chamber 11, that is, at a position immediately before the working medium completes its expansion process.

A pi/#x outlet hole 22 is provided in a part of the discharge port body 20, and communicates with the bypass introduction hole 21 via a communication path 21. An expansion check valve 24 is provided in the middle of this communication path z1, and these constitute a bypass circuit 2j.

As a result, the working medium guided between the vanes 181 to lad is sequentially expanded, applies rotational force to the rotor 1#, and is discharged from the discharge port body 20. Now, as shown in Fig. 3, when the pressure in the condenser 1 rises from Po to P', the pressure between the vane J a 1 and the vane 71#b becomes one lower than the condensing pressure P'. However, under the influence of this pressure difference, the check valve 24 becomes open. The working medium flows from the discharge port body 20 through the bypass circuit 2J to the vanes 18a and 18b, as shown by the dashed-dotted line arrow in the figure. ′
The working medium is directed to the site just before completing the expansion process. 0-Co as shown in Figure 3
The expansion process between is omitted, and the output of the rotor 19 is A −1
There is no overexpansion loss, as expressed by the area surrounded by -0-D'.If the condensation pressure rises further from P',
Since the position of intersection 0 also rises, the rotational force decreases, and conversely, if the condensing pressure decreases from P', the rotational force increases.

In any case, the amount of opening of the check valve 24 varies depending on the pressure difference, and the working medium is guided to a portion immediately before completing the expansion process, and the pressure becomes equal to the condensation pressure, so there is no overexpansion loss.

In the above embodiment, the pi/paraspice circuit 2J is provided in the expander 1, but the invention is not limited to this. For example, as shown in FIG. Pi/4 space pipe 2Rh and this pipe/4 space pipe 2j that communicate the midway part of the communicating pipe P with a predetermined portion of the expander 11
The pi/rath pipe jja may be configured with the open/close valve j4m provided in the middle part of a, and one end of the pi/rath pipe jja is located at the position of the pi/fourth inlet hole 21 shown in FIG. It's the same. The on-off valve JJm opens only when the condensing pressure exceeds a predetermined pressure. As a result, the same effect as in the above embodiment is obtained.

Furthermore, it goes without saying that various modifications can be made without departing from the gist of the present invention.

As explained above, according to the present invention, the position immediately before the expansion of the working medium in the d1 expander is communicated with the introduction side part of the condenser, and the d/yarn is opened when the condensing pressure is higher than a predetermined pressure. Since the circuits and paths are provided, the mutual pressures are the same, and there is no generation of rotational force in opposite directions.Therefore, there is an effect that overexpansion loss can be eliminated and operational efficiency can be improved.

[Brief explanation of drawings]

Fig. 1 is a Rankine cycle configuration diagram, tK2 is a longitudinal sectional view of the main parts of an expander showing a conventional example of the present invention, Fig. 3 is a p-v characteristic diagram showing medium changes in a Rankine cycle device,
FIG. 4 is a vertical cross-sectional view of the main parts of an expander showing one embodiment of the present invention, and FIG. 5 is a configuration diagram of a Rankine cycle showing another embodiment of the present invention. 1--expander, 2--condenser, 3--circulation pump,
4...Steam generator, j l # I i a ·-bis 4th circuit. Applicant's agent Patent attorney Takehiko Suzue 1111 Figure 4 Figure 5

Claims (1)

[Claims] In a device in which a working medium is repeatedly circulated in the order of an expander, a condenser, a circulation chamber, and a steam generator, the position immediately before the expansion of the working medium in the expander is completed and the working medium introduction side of the condenser. A Rankine cycle device, characterized in that a pi/spring circuit is provided which communicates with the parts, and the pi/#s circuit is opened when the condensation pressure is higher than a predetermined pressure.