JPS59115407A - Cold heat power generating equipment - Google Patents

Abstract

PURPOSE:To improve a power generating equipment and to enable continuous operation of it for a long time, by a method wherein means for preventing a liquefied medium from being fed in accompany with an evaporated medium fed from a medium vaporizer to a medium turbine are mounted to a Rankine cycle type LNG cold heat power generating equipment. CONSTITUTION:An LNG vaporizer 10 and a medium pump 11 are interconnected through a conduit 20, the medium pump 11 and a medium vaporizer 12 through a conduit 21, the medium vaporizer 12 and a medium turbine 13 through a conduit 22, and the medium turbine 13 and the LNG vaporizer 10 through a conduit 23 to form a Rankine cycle, and a generator 14 is coupled to the medium turbine 13. A bubble detecting means, for example, a level switch 70 is situated below a demister 60 and above the surface level of a liquid medium, and an oil separator 16 is coupled to the medium vaporizer 12 through a conduit 80. A level switch 70 is connected to a drain valve 90 of the conduit 80, and bubble, produced during boiling of the liquefied medium in the medium vaporizer, is prevented from reaching the demister 60, and this prevents the liquefied medium from being supplied in accompany with an evaporated medium fed from the medium vaporizer 12 to the turbine 13.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to cryogenic power generation equipment, and particularly relates to Rankine cycle LNG cryogenic power generation equipment.

[Prior art]

T, NG
Consisting of an evaporator, medium pump, medium evaporator, medium turbine, and generator, Freon R-22 is installed in the Rankine cycle system.
, a fluorine compound such as Freon R-13B1, and a hydrocarbon whose main component is propane are sealed in a predetermined amount as a Rankine medium. Rankine cycle type LNG cryothermal power generation equipment is known.

In conventional Rankine cycle type LNG cryogenic power generation equipment, as the operating time passes, the medium is evaporated in the medium evaporator, which is supplied from the medium evaporator to the medium turbine.

Liquefied Rankine medium (hereinafter referred to as liquefied medium) comes to be entrained in the vaporized Rankine medium (hereinafter referred to as liquefied medium) in the form of a mist, which causes abnormal vibrations and noises to occur in the medium turbine. Experienced difficulty in continuing to drive.

This is because the oil used in the media turbine, such as seal oil and bearing lubricating oil, gets mixed into the Rankine medium during operation, and because the boiling point of the oil is higher than that of the Rankine medium, it accumulates in the media evaporator. This occurs because the oil concentration in the liquefied medium remaining in the medium evaporator exceeds a certain level, and when the liquefied medium boils, foam begins to form. Foam height above boiling surface (
The boiling surface foam height (hereinafter abbreviated as boiling surface foam height) increases as the oil concentration increases. The foam finally reaches the demister housed in the medium evaporator, and as a result, the liquefied medium is entrained in the form of a mist in the vaporized medium supplied from the medium evaporator to the medium turbine.

Conventionally, when such a situation occurs, it has been dealt with by temporarily stopping the operation and replacing the Rankine medium with a new one. There was also a drawback that a large amount of Rankine media was required, increasing the cost of Rankine media.

[Purpose of the invention]

An object of the present invention is to provide a cryogenic power generation facility that can operate a Rankine-Sike dual-type LNG cryogenic power generation facility favorably and continuously for a long period of time by preventing abnormal vibrations and abnormal noises of a medium turbine.

[Summary of the invention]

The present invention provides a foam detection means below the demister housed in the medium evaporator and above the surface of the liquefied medium retained in the medium evaporator, and also includes an oil separator in the medium evaporator.
The device is characterized in that it is connected by a conduit provided with a withdrawal valve that is operated by a foam detection means to prevent foam generated when the liquefied medium boils in the medium evaporator from reaching the demister. This is to prevent the liquefied medium from being entrained in the vaporized medium supplied from the medium evaporator to the medium turbine.

[Embodiments of the invention]

An embodiment of the present invention will be described with reference to the drawings.

In the drawing, the LNG evaporator 10 and the medium pump 11 are connected to a conduit, the medium pump 11 and the medium evaporator 12 are connected to a conduit 4, and the medium evaporator 12 and the medium turbine 13 are connected to a conduit B.
The medium tank 13 and the LNG evaporator 10 are connected to form a Rankine cycle through a conduit, and the medium turbine 13 is connected to a generator 14 . In addition, in the Rankine cycle system, Freon R-22, Freon R-1
A predetermined amount of a fluorine compound such as No. 381 and a hydrocarbon whose main component is propane are sealed as a fluorine medium.

The LNG evaporator 10 and the medium evaporator 12 each have a heat exchanger tube region 31 installed therein. The inlet of the heat exchanger tube (equipment) is connected to an LNG storage tank (not shown) and is connected to an LNG storage tank (not shown).
A conduit 40 provided with a G pump (not shown) is connected, and a conduit 40 connected to an NG heater 15 is connected to the outlet.
1 are connected. The NG heater 15 includes a heat transfer tube 32
is installed inside, and the inlet and outlet of the heat transfer tube 32 and the guard are connected to the conduit 5.
0.51 are connected to each other. The NG heater 15 is connected to another user, for example, a combustion boiler (not shown), through a conduit 42.

In addition, conduits 52 and 53 are provided at the inlet and outlet of the heat exchanger tube 31.
are connected to each other, and a demister 60 is installed in the medium evaporator 12 at a position above the medium evaporator 12.

Below the demis 60 and above the liquid level of the liquefied medium,
A level switch (hereinafter abbreviated as a level switch) 70 using a foam detection means, for example, a resistance thermometer sensor is provided, and the medium evaporator 12 is equipped with an oil separator 1.
6 are connected by a conduit.

An extraction valve is installed between the conduits, and the extraction valve is 1,
4.

It is connected to the level switch 70. Oil separator 161
Here, a heat exchanger tube 33 is installed inside, and conduit barbs 55 are connected to the inlet and outlet of the heat exchanger tube section, respectively.

Further, a conduit 81 provided with a valve 91 is connected to the bottom of the oil separator 16, and a conduit 82 is connected to the top. Note that the conduit 82 is connected to the medium evaporator 12 at a position above the demister ω, for example.

LN'G supplied from the LNG storage tank to the heat exchanger tube region by the LNG pump is vaporized by condensing and liquefying the vaporization medium in the LNG evaporator 10, heated in the NG heater 15, and then separately sent to the user. be done. On the other hand, the liquefied medium is supplied to the medium evaporator 12 by the medium pump 11, stays in the medium evaporator 12 and boils, and a part of it is evaporated and vaporized. After passing through the demister 60, the vaporized medium is supplied from the medium evaporator 12 to the medium turbine 13 to drive the medium turbine 13. This drives the generator 14, and as a result, the cold energy held by the LNG is converted into electrical energy and recovered. By driving the medium bottle 13, the vaporized medium whose pressure and temperature have decreased becomes LNG.
After being returned to the evaporator 10, it is condensed again by T, NG.

liquefied.

With the continuation of the operation as described in 2 above, the seal oil, bearing lubricating oil, etc. used in the medium turbine 13 leak into the vaporized medium, and this leaked oil mixes into the liquefied medium remaining in the medium evaporator 12. , is accumulated. When the oil concentration in the liquefaction medium exceeds a certain concentration, foam begins to form when the liquefaction medium boils, and the boiling surface foam height increases as the oil concentration in the liquefaction medium increases.

In this case, when the height of the boiling surface foam reaches the contact point of the level switch 70, an operation signal is output from the level switch 70 to the extraction valve, and the extraction valve is opened.

As a result, oil remains in the medium evaporator 12 and is mixed in, and a part of the accumulated medium is extracted to the oil container 16. In the oil separator 16, a heat transfer tube 331 is supplied from a conduit 55,
After flowing through the heat transfer tube section, the liquefied medium is evaporated and vaporized by the heat medium discharged from the conduit barbs, and the Rankine medium and the oil are separated. The vaporized medium is returned to the Rankine cycle system by being supplied from the oil separator 16 to the -E side of the demister 60 of the medium evaporator 2, and is then returned to the medium evaporator bottle 13 together with the vaporized medium that has passed through the demister 6o. supplied to

On the other hand, the separated oil is extracted from the oil separator 16 and then discharged to the outside of the system. - The following effects can be obtained with the cold power generation equipment as in this example.

(1) When the boiling surface foam height reaches the contact point of the level switch, a part of the liquefied medium mixed with oil and accumulated from the medium evaporator is discharged to the oil separator. The distance between the liquid level of the liquefied medium and the lower surface of the demister increases, and the height of foam at the boiling surface decreases relatively. In addition, after being extracted from the medium evaporator to the oil separator, it is separated into Rankine medium and oil in the oil separator, and the separated Rankine medium is returned to the Rankine cycle system, while the separated oil is removed from the system. Therefore, the oil concentration in the liquefied medium remaining in the medium evaporator can be reduced, and the foam height itself can be reduced.

(2) In this way, the height of the foam on the l'JllIli surface is relatively reduced, and the height of the foam on the boiling surface itself is reduced, so it is possible to prevent the foam from reaching the demister,
It is possible to prevent the liquefied medium from being entrained in the vaporized medium supplied from the medium evaporator to the medium turbine.

Therefore, the generation of abnormal vibrations and noise in the medium turbine can be prevented, so that the cold power generation equipment can be operated continuously for a long period of time without stopping the operation.

(3) There is no need to replace the Rankine medium with a new Rankine medium, and the Rankine medium separated from the oil is returned to the Rankine cycle system.
No need to replenish. Therefore, an increase in Rankin media costs can be prevented.

〔Effect of the invention〕

As explained above, the present invention provides the foam detection means below the demister installed in the medium evaporator and above the liquid level of the liquefied medium staying in the medium evaporator, and also provides the foam detection means in the medium evaporator. The separator is equipped with a extraction valve that is opened and closed by a foam detection means.

By connecting with a pipe, it is possible to prevent the liquefied medium from being entrained in the vaporized medium supplied from the medium evaporator to the medium turbine, and it is possible to prevent abnormal vibrations and noise from occurring in the medium turbine.
This has the effect of allowing cold power generation equipment to operate smoothly and continuously over a long period of time.

[Brief explanation of drawings]

The drawing is a system diagram showing an embodiment of the Rankine cycle type LNG cryogenic power generation equipment according to the present invention.

Claims (1)

[Claims] 1. In the Rankine cycle type LNG cryothermal power generation equipment, a foam detection means is provided below the demister installed in the medium evaporator and above the liquid surface of the liquefied Rankine medium retained in the medium evaporator 1, and A cryogenic power generation facility characterized in that an oil separator is connected to the vessel through a conduit provided with a withdrawal valve that is opened and closed by means of detecting foam.