JPH0675091A - Recovery method and device of seed used for mhd power generation - Google Patents

Abstract

PURPOSE:To conveniently continuously perform cooling of working fluid and recovery of seed without any need of delicate temperature control. CONSTITUTION:Valves 44A, 44B are alternately opened and rare gas and seed derived from an MHD generator 40 are alternately introduced to rare gas coolers 24A, 24B. The rare gas is cooled by heat exchange with cooling water in the rare gas cooler 24A (or 24B) introducing the rare gas, the seed contained therein is condensed and solidified. On the other hand, the seed solidified therein is heated and melted in the rare gas cooler 24B (or 24A) without any introduction of the rare gas for the purpose of regeneration of the rare gas cooler together with recovery of the seed.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method and apparatus for recovering seeds used in MHD power generation, particularly closed cycle MHD power generation, from a working fluid such as a rare gas.

[0002]

2. Description of the Related Art Recently, as one of the useful power generation methods, M
HD (Magneto-Hydro-Dynamic) power generation is under development. This MHD power generation utilizes a phenomenon (Faraday's law) in which electromotive force is generated by electromagnetic induction in a direction orthogonal to both when a conductive working fluid is flowed in a direction orthogonal to the magnetic field. An open cycle type using a combustion gas as a fluid and a closed cycle type using a rare gas such as helium gas or argon gas as a working fluid are well known.

FIG. 2 shows a conventional closed cycle MHD.
It shows an example of a power generation system. This system includes a combustion gas supply circuit 10 and a rare gas circulation circuit 20.

In the combustion gas supply circuit 10, combustion air is pressure-fed to the combustor 16 by the air compressor 13 driven by the combustion gas turbine 14, and combustion gas is generated by combustion of fuel in the combustor 16. . This combustion gas is passed through a rare gas heater (heat storage type heat exchanger), and then burned again in the secondary combustor 18, and the air compressor 13 is used.
It is discharged to the outside through the combustion gas turbine 14 that is linked with the.

On the other hand, in the rare gas circulation circuit 20, the rare gas which is the working fluid is sent to the rare gas heater 30 by the operation of the rare gas turbine 26 and heated by the combustion gas in the rare gas heater 30. It is heated to a high temperature by exchanging heat with the ceramic heat storage body. A seed made of an alkali metal such as potassium or cesium is added to the high-temperature rare gas by the pump 28, whereby the rare gas is turned into plasma. The rare gas whose conductivity is increased by such plasma formation is supplied to the MHD generator 40,
A large electromotive force is generated by passing through the magnetic field formed in the MHD generator 40, and its electric output is taken out through the inverter 42.

From the MHD generator 40, the rare gas and the seed are led out in a mixed state, and the mixed fluid is passed through the rare gas regenerating heat exchanger 22 and cooled to generate the seed gas. Most of it is condensed, recovered from the downstream portion of the rare gas regeneration heat exchanger 22, and re-supplied to the MHD generator 40 by the pump 28. The remaining fluid is further cooled in the rare gas cooler 24.

As shown in FIG. 3, the rare gas cooler 24 has a horizontally extending cylindrical main body 24a and a main body 24a.
A heat transfer tube 24b meandering inside is provided, and the fluid passed through the main body 24a is cooled by heat exchange with the cooling water passed through the heat transfer tube 24b. By this cooling, the seeds in the fluid are condensed and collected from the drain discharge port 24c to a liquefied seed collection tank (not shown), and then reused. The remaining noble gas is compressed by the noble gas compressor 25 shown in FIG. 2, heated by the noble gas regenerative heat exchanger 22, and then returned to the noble gas turbine 26. The rare gas compressor 25 is driven to rotate.

[0008]

The rare gas cooler 24 described above is used.
In the above, if the surface temperature of the heat transfer tube 24b is lower than the melting point of the seed, the seed is solidified on the surface of the heat transfer tube 24b and the heat exchange between the rare gas and the cooling water is hindered. Can't hope for. Therefore, in the above-mentioned conventional device, it is necessary to keep the surface temperature of the heat transfer tube higher than the melting point of the seed and to keep it in a relatively narrow temperature range in which the rare gas can be effectively cooled. It varies greatly depending on the flow velocity, and it is not easy to control this accurately. In addition, the melting point of the seed is relatively high (about 64 ° C. for potassium), and there is a large difference between the target temperature (about 80 ° C.) on the surface of the heat transfer tube and the cooling water temperature corresponding to the melting point. If there is a fluctuation, for example, a decrease in the flow rate of the rare gas, it may be impossible to keep the heat transfer tube surface temperature below the target temperature.

In view of such circumstances, it is an object of the present invention to provide a method and apparatus capable of continuously cooling a working fluid and recovering a seed without inconvenience, without requiring delicate temperature control. And

[0010]

SUMMARY OF THE INVENTION The present invention is a method for cooling a working fluid derived from an MHD generator and condensing and recovering the seed contained in the working fluid. A fluid cooler is prepared, and by cooling the working fluid by introducing the working fluid into only some of the working fluid coolers, the seeds contained in the working fluid are solidified in the working fluid cooler, and in the meantime. The seed solidified in another working fluid cooler is heated and melted, and the seed is taken out from the working fluid cooler (claim 1).

The present invention is also an apparatus for carrying out the above method, wherein a plurality of working fluid coolers are connected in parallel to the MHD generator, and each working fluid cooler and the MHD are connected.
An opening / closing means is provided between the generator and the generator for switching between an open state in which the working fluid is passed and a closed state in which the working fluid is shut off (claim 2).

[0012]

According to the method of claim 1, the seed may be solidified in the working fluid cooler in use, so that the cooling temperature in the working fluid cooler may be lower than the melting point of the seed. At this temperature, the working fluid can be sufficiently cooled and the seed can be reliably separated from the working fluid. Then, after the working fluid cooler is used, the inside of the working fluid cooler is heated while the other working fluid cooler is used, and the solidified seed is melted to operate the seed. It can be recovered from the fluid cooler.

Continuous operation can be realized by performing the above-mentioned operation and regeneration operation while shifting the phases of the working fluid coolers.

Specifically, according to the apparatus of claim 2,
By opening a specific opening / closing means, a working fluid can be made to flow into a working fluid cooler connected to this opening / closing means to be in use, and by closing the opening / closing means, it is connected to this opening / closing means. The supply of the working fluid to the working fluid cooler can be stopped, and the working fluid cooler can be regenerated (that is, the solidified seed is melted) in this state.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described with reference to FIG.

The closed cycle MHD power generation system shown in the same figure is similar to the system shown in FIG. 2, and the combustion gas supply circuit 10, the rare gas circulation circuit 20, the high temperature rare gas heater 30, the MHD generator 40, and the An inverter 42 is provided, a generator 12, an air compressor 13, a combustion gas turbine 14, a combustor 16, and a secondary combustor 18 are provided in the rare gas circulation circuit 20, and the rare gas circulation circuit 20 includes a rare gas. Regeneration heat exchanger 22, rare gas compressor 25, rare gas turbine 2
6, and a pump 28 for seed supply.
Here, the function of each element is exactly the same as that described in FIG. 2, and the description thereof is omitted here.

The feature of this apparatus is that between the rare gas regeneration heat exchanger 22 and the suction side of the rare gas compressor 25,
Two rare gas coolers 24A and 24B are connected in parallel with each other. Each of the rare gas coolers 24A and 24B has the same structure as that shown in FIG.
Similar to the rare gas cooler 24 shown in FIG.
And a heat transfer tube 24b that meanders in the main body 24a and allows cooling water to pass therethrough, and a drain discharge port 24c is provided at the bottom of the main body 24a. Then, as shown in FIG. 1, the primary sides of the rare gas coolers 24A and 24B are connected to the rare gas regeneration heat exchanger 22 via valves (opening / closing means) 44A and 44B, respectively, to cool the rare gas coolers. Bowl 24
The secondary sides of A and 24B are connected to the primary side of the rare gas compressor 25 via valves 46A and 46B, respectively.

Next, a method of operating this device will be described.

First, at the start of use, the valves 44A and 46A
Open and close valves 44B and 46B. By operating the rare gas turbine 26 in this state, the rare gas is supplied to the high temperature rare gas heater 30 and is heated to a high temperature by exchanging heat with the ceramic heat storage body heated by the combustion gas from the combustor 16. To do. Further, by injecting a seed from the pump 28 into this rare gas, the rare gas is turned into plasma and supplied to the MHD generator 40 to generate power.

From the MHD generator 40, the rare gas and the seed are led out in a mixed state, and the rare gas regeneration heat exchanger 2
Most of the seeds are condensed by cooling through 2. This seed is recovered from the downstream side portion of the rare gas regeneration heat exchanger 22 and re-supplied to the MHD generator 40 by the pump 28.

The remaining fluid is introduced into the rare gas cooler 24A through the valve 44A and further cooled. Specifically, the mixed fluid is cooled by passing it through the main body 24a shown in FIG. 3 and exchanging heat with the cooling water passed through the heat transfer tube 24b. At this time, the surface temperature of the heat transfer tube 24b may be set sufficiently low and may be lower than the melting point of the seed. The seed in the fluid introduced into the rare gas cooler 24A is condensed, further solidified, and adheres to the surface of the heat transfer tube 24b. The remaining noble gas is introduced into the noble gas compressor 25 through the valve 46A, compressed there, and then heated by the noble gas regeneration heat exchanger 22, and then the noble gas turbine 2
6, the rare gas turbine 26 and the rare gas compressor 25 are rotationally driven by the kinetic energy.

By continuing such operation, the heat transfer tube 24b
When the solidification of the seeds on the surface progresses, good heat exchange is finally prevented. However, before such a hindrance to heat exchange occurs, the valves 44A and 46A are closed and the valve 44A is closed.
B and 46B are opened and the cooler used is a noble gas cooler 24
Switch from A to the noble gas cooler 24B. With this new rare gas cooler 24B, good operation can be continued.

During the use of the rare gas cooler 24B, the rare gas cooler 24A is regenerated. In particular,
Into the heat transfer tube 24b of the rare gas cooler 24A, hot water having a temperature higher than the melting point of the seed is introduced instead of the cooling water.
As a result, the seeds fixed to the surface of the heat transfer tube 24b are melted and dropped from the heat transfer tube 24b, and the drain discharge port 2
4c is recovered in a liquefied seed recovery tank (not shown) for reuse. By such a regeneration operation, the rare gas cooler 2
4A can be returned to a usable state again.

Therefore, as shown in Table 1 below, 2
By alternately using the base rare gas coolers 24A and 24B and performing regeneration when not in use, it is possible to continuously perform seed recovery and rare gas cooler without inconvenience.

[0025]

[Table 1] Noble gas cooler 24A: Use → regeneration → use → regeneration → use → ... Noble gas cooler 24B: Regeneration → use → regeneration → use → regeneration → ... Here, "use" means a rare gas cooler The step of introducing a mixed fluid into the heat transfer tube 24b to condense and solidify the seed on the surface of the heat transfer tube 24b, and "regeneration" heats the surface of the heat transfer tube 24b to melt the seed, and collects it from the drain outlet 24c. Means the step of performing.

The present invention is not limited to such an embodiment, and the following modes can be adopted as an example.

(1) In the present invention, the effect can be obtained if the number of working fluid coolers is not particularly limited as long as it is plural. For example, three noble gas coolers 24a, 24
When using b and 24C, each rare gas cooler 24A,
The steps shown in Table 2 below may be performed in 24B and 24C.

[0028]

[Table 2] Noble gas cooler 24A: Use → regeneration → standby → use → regeneration → ... Noble gas cooler 24B: Regeneration → standby → use → regeneration → standby → ... Noble gas cooler 24C: standby → use → regeneration → Standby → Use → ... Here, “standby” means a state in which the regeneration process is completed and preparation for use is started.

(2) In the present invention, regardless of the specific means for heating the inside of the working fluid cooler during the regeneration step, hot water is passed through the heat transfer tube 24b as described above, and an electric heater is used. You may make it install heating means, such as this in a cooler.

(3) In the present invention, regardless of the specific type of the MHD generator 40, seeds used in various conventionally known MHD generators such as a disk type generator and a linear type generator are used. The present invention can be applied to recovery.

(4) In the present invention, regardless of the specific structure of each working fluid cooler, in addition to the one shown in FIG. 3, a multi-tube heat exchanger, fin / tube heat exchanger, fin / plate heat exchanger is used. Various heat exchangers and the like such as a vessel can be applied.

[0032]

As described above, the present invention uses a plurality of working fluid coolers, and while some working fluid coolers cool the working fluid, the working fluid coolers solidify in other working fluid coolers. Since the seeds are heated and melted to regenerate the working fluid cooler, the working fluid coolers can be alternately used for continuous operation. Moreover, unlike the conventional case, it is not necessary to keep the cooling temperature in each working fluid cooler high in order to avoid the solidification of the seed, so that the temperature control is very easy and the load such as the flow rate of the working fluid is reduced. Even if fluctuations occur, cooling of the working fluid and seed recovery can be continued without any inconvenience.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of an MHD power generation system according to an embodiment of the present invention.

FIG. 2 is an overall configuration diagram showing an example of a conventional MHD power generation system.

FIG. 3 is a sectional view showing an example of a rare gas cooler installed in the system.

[Explanation of symbols]

 24A, 24B Noble gas cooler (working fluid cooler) 40 MHD generator 44A, 44B valve (opening / closing means)

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshio Kurosaka 1-5-5 Takatsukadai, Nishi-ku, Kobe City Kobe Steel Research Institute, Kobe Steel Research Institute

Claims (2)

[Claims] 1. A method for cooling a working fluid derived from an MHD generator and condensing and collecting seeds contained in the working fluid, wherein a plurality of working fluid coolers are provided, among which a plurality of working fluid coolers are provided. By introducing and cooling the working fluid only in a part of the working fluid cooler, the seed contained in the working fluid is solidified in the working fluid cooler, and in the meantime, in the other working fluid cooler. A method for recovering a seed used for MHD power generation, characterized in that the solidified seed is heated and melted and taken out from the working fluid cooler. 2. An apparatus for cooling a working fluid derived from an MHD generator and condensing and collecting seeds contained in the working fluid, wherein the MHD generator has a plurality of working fluid coolers. In parallel with each other, and provided between the working fluid coolers and the MHD generator with opening / closing means for switching between an open state for passing the working fluid and a closed state for shutting off the working fluid. The seed recovery device used.