JP3106689B2 - Gas cooler for high temperature gas - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas cooler for high-temperature gas, and more particularly to a structure of a gas cooler for cooling high-temperature coal gas.

[0002]

2. Description of the Related Art Development of a coal gasification and power generation plant for generating electricity by gasifying coal in a gasifier, removing the resulting crude gas by dust removal and desulfurization to produce a refined gas, and burning it with a gas turbine to generate electricity is currently underway. ing. In such power plants,
A high-temperature gas cooler is used to cool the high-temperature crude gas at 1200 ° C. to 1300 ° C. to a temperature suitable for the purification step (for example, 400 ° C. or less) and at the same time recover heat energy from the high-temperature crude gas. This gas cooler includes, for example, as shown in FIG. 3, a tower body 10 having a vertically extending space therein, and a plurality of steam heat exchangers 20 for heating the steam 1, and a plurality of steam heat exchangers 20 in the space. A steam heat exchanger is arranged. The high-temperature crude gas 2 flows in from the lower part of the gas cooler tower body, is recovered in heat by the steam heat exchanger, is cooled down, and flows out from the top part. The crude gas 2 that has exited the gas cooler is purified by a dust removal / desulfurization facility (not shown) provided on the downstream side to become a purified gas 3 suitable for combustion in a gas turbine. Since the temperature of the purified gas 3 is considerably lower than that of the crude gas 2 (for example, 300 ° C. or lower), the purified gas 3 which has exited the gas cooler is usually provided by the purified gas heat exchanger 30 provided separately from the gas cooler.
And is supplied to the gas turbine.

[0003]

Since the crude gas flows into the gas cooler from below the coal gasifier and flows out from the top, it needs to be lowered in a high-temperature duct in order to proceed to the next step. However, the height of the gas cooler outlet is usually 50m
Since the temperature has reached the above and the temperature is high, not only the cost of the duct is increased, but also the heat loss from the duct is large.

[0004] Further, the crude gas leaving the gas cooler is also used for reheating the purified gas that has been dedusted and desulfurized. For this purpose, it is necessary to provide a separate heat exchanger. There is a problem that heat dissipation is large because it is used alone.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a gas cooler for high-temperature gas which solves such a problem, does not require a high-temperature duct, and can reduce heat dissipation loss.

[0006]

According to the present invention, there is provided a tower having a vertically extending space therein, a plurality of fluid heat exchangers for heating a fluid, and a gas for heating a gas. A heat exchanger, and the tower body has a vertically extending partition wall that partitions the space into an ascending portion and a descending portion, and the partition wall communicates with the upper end portion of the ascent portion and the descending portion. Portion, the tower body further has a hot gas inlet provided at the lower portion of the rising portion, and a hot gas outlet provided at the lower portion of the descending portion, the plurality of A high-temperature gas gas cooler is provided, wherein the fluid heat exchanger and the gas heat exchanger are arranged in a space from an inlet to an outlet of the high-temperature gas.

According to a preferred embodiment of the present invention, the plurality of fluid heat exchangers are arranged in series along a flow of hot gas, and the gas heat exchanger is downstream of the fluid heat exchanger. Placed on the side. It is preferable that the plurality of fluid heat exchangers are steam convection heat exchangers arranged so that steam flows from the downstream to the upstream with respect to the flow of the high-temperature gas. Further, it is preferable that the plurality of fluid heat exchangers are water heat exchangers arranged so that water flows upward from below. Further, it is preferable that the partition wall is a water cooling wall in which heat transfer tubes and fins through which cooling water passes are alternately welded.

[0008]

According to the structure of the present invention, the high-temperature gas enters the gas cooler from the inflow port, rises up the rising portion along the heat exchanger, enters the descending portion through the communicating portion of the partition wall, and enters the descending portion. Descends along the heat exchanger and exits the gas cooler at the outlet. Therefore, the height of the gas cooler outlet is, for example, 5
Even when the temperature reaches 0 m or more, a high-temperature duct for lowering the high-temperature gas is not required, so that the cost of the duct is not increased and the heat loss from the duct can be greatly reduced. In addition, the degree of accumulation in the tower
, The tower top is also lowered. Further, since the gas heat exchanger is disposed in the gas cooler, heat radiation loss from the gas heat exchanger is greatly reduced.

Further, if a plurality of fluid heat exchangers are arranged in series along the flow of the hot gas and the gas heat exchanger is arranged downstream of the fluid heat exchanger, heat recovery of the hot gas can be achieved. , And heating of the fluid and the low-temperature gas can be performed effectively.
Furthermore, if the plurality of fluid heat exchangers are convection heat exchangers for steam in which steam is arranged from the downstream to the upstream with respect to the flow of the hot gas, heat recovery of the hot gas and heating of the steam are performed. Can be performed more effectively. Further, if the plurality of fluid heat exchangers are arranged such that water flows upward from below, steam can be generated effectively.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an overall configuration diagram of a gas cooler for high-temperature gas according to the present invention. In this figure, the gas cooler has a tower body 10 having a space extending in the vertical direction therein,
A plurality of fluid heat exchangers 20 for heating the fluid 1;
A gas heat exchanger 30 for heating the purified gas of the coal gas, that is, the low-temperature gas 3 is provided. The tower body 10 is a pressure vessel configured to receive a high-pressure and high-pressure coal gasification crude gas, that is, a high-temperature gas 2 having a pressure of, for example, 21 ata and a temperature of 950 ° C. or less in an internal space. A gas duct having a water-cooled wall structure is configured to withstand high temperatures. In the case where the fluid 1 is disposed from the downstream to the upstream with respect to the flow of the high-temperature gas as shown in this figure, the fluid 1 is preferably steam and the heat exchanger is preferably a steam heat exchanger.

FIG. 2 is another schematic diagram of the gas cooler for high-temperature gas according to the present invention. This figure differs from FIG. 1 in that the fluid 1 is arranged so as to flow upward from below. When the fluid 1 is arranged to flow upward from below as shown in this figure, the fluid 1 is preferably water and the heat exchanger is preferably a water heat exchanger, that is, an evaporator.

The tower body 10 has a vertically extending partition wall 16 which divides an internal space into an ascending portion 12 and a descending portion 14. The dividing wall 16 communicates the ascending portion 12 and the descending portion 14 at its upper end. The communication portion 16a is provided. The partition wall 16 is made of a water-cooled wall having a sealed structure in which heat transfer tubes and fins made of a material that can withstand the temperature of the high-temperature gas 2, for example, heat-resistant metal are alternately arranged. This water cooling wall may be provided separately on both sides of the partition wall 16, that is, on the ascending portion 12 and the descending portion 14, or the partition wall 1 may be formed by one water cooling wall.
6 may be formed, and the rising part 12 and the falling part 14 may be partitioned by the water cooling wall. The shape of the partition wall 16 may be a vertical plane, or may draw an arbitrary curve. Further, the shape of the partition wall 16 may be determined so that the rising portion 12 and the falling portion 14 have a circular or rectangular shape suitable for accommodating the heat exchanger.

An inlet 12a for the hot gas 2 is provided below the rising portion 12, and an outlet 14a for the hot gas 2 is provided below the lower portion 14. Also, in the space from the inlet 12a to the outlet 14a of the high-temperature gas,
A fluid heat exchanger 20 and a gas heat exchanger 30 are arranged. The fluid heat exchanger 20 may be a steam heat exchanger as in FIG. 1 or a water heat exchanger or evaporator as in FIG. Fluid heat exchanger 20
The size and quantity are determined arbitrarily according to the amount of heat recovered from the high-temperature gas 2, but are usually two or more, and may be seven or more. The number of gas heat exchangers 30 for heating the purified gas of the coal gas, that is, the low-temperature gas 3 is usually one, but may be two or more. It is preferable that the fluid heat exchanger 20 and the gas heat exchanger 30 have substantially the same outer shape and dimensions.

The plurality of fluid heat exchangers 20 are provided with hot gas 2
And the gas heat exchanger 30 is arranged downstream of the fluid heat exchanger 20. When a plurality of fluid heat exchangers are arranged such that steam flows from the downstream to the upstream with respect to the flow of the hot gas as shown in FIG. 1, the heat exchanger is a convective heat exchanger for steam. Is good. In a convection type heat exchanger, steam flows inside a tube or tube, and hot gas flows outside the tube, so that heat exchange is effectively performed. If the fluid 1 or water is arranged to flow from bottom to top as in FIG. 2, the heat exchanger may have a vertical water tube.

In use, the hot gas 2 is supplied to the inlet 12
a, enters the gas cooler, rises the rising portion 12 along the fluid heat exchanger 20, enters the descending portion 14 through the communication portion 16a of the partition wall 16, and descends the descending portion 14 along the heat exchanger. Exits the gas cooler through the outlet 14a. When the heat exchanger 20 is a steam heat exchanger (FIG. 1), the fluid 1
That is, the steam flows from the downstream to the upstream with respect to the flow of the high-temperature gas in the plurality of convection heat exchangers 20 arranged in series, and is superheated by heat exchange with the high-temperature gas 2 to be taken out from the gas cooler. When the heat exchanger 20 is a water heat exchanger (evaporator) (FIG. 2), the fluid 1, that is, water flows upward from below in the water heat exchanger arranged in series, and Is converted into vapor by heat exchange with the gas cooler. The purified gas of the coal gas, that is, the low-temperature gas 3 is heated by the relatively low-temperature gas before leaving the gas cooler in the gas heat exchanger 30 arranged downstream of the fluid heat exchanger 20.

[0016]

According to the configuration of the present invention described above, even when the height of the gas cooler outlet reaches 50 m or more, a high-temperature duct for lowering the high-temperature gas is unnecessary, and the cost of the duct is not increased. In addition, heat loss from the duct can be significantly reduced. Further, it is possible to increase the degree of accumulation in the tower and lower the tower top. Further, since the gas heat exchanger is also disposed in the gas cooler, the heat radiation loss from the gas heat exchanger is greatly reduced.

Further, if a plurality of fluid heat exchangers are arranged in series along the flow of the hot gas and the gas heat exchanger is arranged downstream of the fluid heat exchanger, heat recovery of the hot gas can be achieved. , And heating of the fluid and the gas can be performed effectively. Further, the plurality of fluid heat exchangers may be a convective heat exchanger for steam in which the steam is arranged from the downstream to the upstream with respect to the flow of the hot gas, and the heat recovery of the hot gas and the heating of the steam may be performed. Can be performed more effectively. Further, if the plurality of fluid heat exchangers are arranged such that water flows upward from below, steam can be generated effectively.

Therefore, according to the present invention, it is possible to eliminate the need for a high-temperature duct and to reduce the heat radiation loss.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a gas cooler for high-temperature gas according to the present invention.

FIG. 2 is another overall configuration diagram of the gas cooler for high-temperature gas according to the present invention.

FIG. 3 is an overall configuration diagram of a conventional gas cooler for high-temperature gas.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fluid 2 High temperature gas 3 Low temperature gas 10 High temperature gas cooler 12 Ascending part 12a Inlet 14 Descending part 14a Outlet 16 Partition wall 20 Fluid heat exchanger 30 Gas heat exchanger

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-59-211702 (JP, A) JP-A-62-81489 (JP, A) JP-A-60-92413 (JP, A) JP-A 60-81 158293 (JP, A) JP-A-63-54514 (JP, A) JP-A-63-120824 (JP, A) JP-A-64-56787 (JP, A) JP-A-57-501299 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) F02C 3/28 C10J 3/46 F02C 6/18

Claims (5)

(57) [Claims] 1. A tower body having a vertically extending space therein, a plurality of fluid heat exchangers for heating fluid,
A gas heat exchanger for heating gas, wherein the tower body has a vertically extending partition wall that partitions the space into an ascending portion and a descending portion, and the partition wall has an ascending portion at an upper end thereof. And a communicating portion communicating the descending portion, the tower body further includes an inlet for a high-temperature gas provided at a lower portion of the ascending portion, and an outlet for a hot gas provided at a lower portion of the descending portion. And wherein the plurality of fluid heat exchangers and the gas heat exchanger are disposed in a space from an inlet to an outlet of the high-temperature gas. 2. The heat exchanger for a plurality of fluids is arranged in series along a flow of hot gas, and the heat exchanger for a gas is arranged downstream of the heat exchanger for a fluid. The gas cooler for high-temperature gas according to claim 1, wherein 3. The heat exchanger for a fluid according to claim 1, wherein the plurality of heat exchangers for fluid are steam convection heat exchangers arranged such that steam flows from a downstream to an upstream with respect to a flow of a high-temperature gas. Item 3. A gas cooler for high-temperature gas according to item 2. 4. The high-temperature gas gas cooler according to claim 2, wherein the plurality of fluid heat exchangers are water heat exchangers arranged so that water flows upward from below. . 5. The high-temperature gas gas cooler according to claim 1, wherein the partition wall is a water cooling wall in which heat transfer tubes and fins through which cooling water passes are welded alternately.