JP2023111272A - direct contact condenser - Google Patents

Abstract

To provide a direct contact condenser capable of suppressing residence of flow inside a downward exhaust type direct contact condenser to maintain a degree of vacuum inside the condenser.SOLUTION: A direct contact condenser is a downward exhaust type condenser in which a plurality of cooling water supply pipes are provided inside a steam condensation unit into which turbine exhaust gas flows, and comprises a plurality of spray nozzles provided in the cooling water supply pipe and arranged in a flow direction of the turbine exhaust. Of the plurality of spray nozzles, the most upstream spray nozzle with respect to the flow direction of the turbine exhaust sprays cooling water obliquely upstream with respect to the flow direction of the turbine exhaust.SELECTED DRAWING: Figure 3

Description

Embodiments of the present invention relate to direct contact condensers.

In a geothermal power plant, a condenser is a device that condenses steam contained in turbine exhaust gas by heat exchange between high-temperature turbine exhaust gas and low-temperature cooling water to keep the exhaust pressure of the turbine at a negative pressure. Since geothermal power plants do not need to reuse condensed water from steam condensed, direct contact condensers, which are simple in structure and advantageous for heat exchange, are often used. Direct contact condensers are mainly classified into a tray (perforated plate) type and a droplet spray type (spray type). In the tray type, the cooling water falling from the tray is atomized by the dynamic pressure of steam, and in the spray type, the cooling water is atomized using a spray nozzle and sprayed into the turbine exhaust. Spray type condensers include a downward exhaust type (upward inflow type) and a horizontal exhaust type (horizontal inflow type).

Steam supplied from geothermal production wells generally contains non-condensable gases such as carbon dioxide. Since the non-condensable gas hinders heat transfer, it is important to cool and discharge the non-condensable gas in a condenser that condenses steam in order to keep the exhaust pressure of the turbine at a negative pressure.

JP-A-11-63857 JP 2010-270925 A JP 2020-26932 A JP-A-2018-35999

When the turbine exhaust and cooling water come into contact with each other in the direct contact condenser, water vapor contained in the turbine exhaust is cooled and condensed, thereby gradually decreasing the flow velocity of the turbine exhaust. As a result, the flow velocity of the turbine exhaust on the downstream side in the flow direction becomes lower than that on the upstream side, so that the flow tends to stagnate. Since non-condensable gas collects where the flow is stagnant, the heat transfer efficiency between the turbine exhaust and the cooling water may deteriorate, and the degree of vacuum in the condenser may deteriorate. If the degree of vacuum in the condenser deteriorates, the power generation efficiency of the geothermal power plant will decrease.

The problem to be solved by the present invention is to provide a direct contact condenser that can maintain the degree of vacuum inside the condenser by suppressing the stagnation of the flow inside the downward exhaust type direct contact condenser. That is.

In order to solve the above problems, the direct contact condenser of the embodiment is a downward exhaust type condenser in which a cooling water supply pipe is provided inside a steam condensation section into which turbine exhaust flows, A cooling water supply pipe is provided with a plurality of spray nozzles arranged in a flow direction of the turbine exhaust, and among the plurality of spray nozzles, the spray nozzle is arranged on the most upstream side with respect to the flow direction of the turbine exhaust. The spray nozzle sprays cooling water obliquely upstream with respect to the flow direction of the turbine exhaust.

Schematic diagram of a geothermal power plant according to the first embodiment Schematic diagram of a cross section in the vertical direction of the direct contact condenser according to the first embodiment Enlarged view of the A section of the direct contact condenser according to the first embodiment Enlarged view of the A portion of the direct contact condenser according to the modified example of the first embodiment Enlarged view of the A portion of the direct contact condenser according to the modified example of the first embodiment Enlarged view of the direct contact condenser according to the second embodiment Enlarged view of a direct contact condenser according to a modification of the second embodiment Enlarged view of a direct contact condenser according to a modification of the second embodiment Enlarged view of the direct contact condenser according to the third embodiment Enlarged view of a direct contact condenser according to a modification of the third embodiment Enlarged view of a direct contact condenser according to a modification of the third embodiment

DETAILED DESCRIPTION OF THE INVENTION Embodiments for carrying out the invention will be described below.

(First embodiment)
A first embodiment will be described with reference to the drawings. FIG. 1 is a schematic diagram of a geothermal power plant according to the first embodiment. As shown in FIG. 1 , the geothermal power plant 30 includes a gas-liquid separator 31 , a dehumidifier 32 , a steam turbine 33 , a generator 34 and a condenser 1 . The arrows in Figure 1 indicate the flow of steam or water.

A gas-liquid separator 31 separates the geothermal fluid from the production well into main steam and hot water. The separated main steam is further removed of water droplets by the dehumidifier 32, passes through a steam control valve (not shown) provided between the dehumidifier 32 and the steam turbine 33, and is supplied to the steam turbine 33. flow into

The steam turbine 33 receives expansion work from the main steam and rotates a generator 34 connected via a turbine rotor (not shown). The generator 34 converts the rotational energy from the steam turbine 33 into electrical energy to generate power. The main steam that has undergone expansion work in the steam turbine 33 flows into the condenser 1 as turbine exhaust.

The condenser 1 cools and condenses water vapor contained in the turbine exhaust. The condensed water condensed in the condenser 1 joins the hot water separated by the gas-liquid separator 31 and the water droplets removed by the dehumidifier 32, and is sent to the reinjection well.

Next, a more detailed configuration of the condenser 1 will be described. FIG. 2 is a schematic diagram of a cross section in the vertical direction of the direct contact condenser according to the first embodiment. 3 is an enlarged view of the A portion of FIG. 2. FIG. FIGS. 4 and 5 are enlarged views of the A portion relating to the modified example of the first embodiment.

As shown in FIG. 2 , the condenser 1 includes a turbine duct 10 into which turbine exhaust discharged from a steam turbine 33 flows, and steam connected to the turbine exhaust duct 10 into which turbine exhaust from the turbine exhaust duct 10 flows. A downward exhaust having a condensation section 11, a cooling water supply pipe 12 for supplying cooling water to the inside of the steam condensation section 11, and a gas cooling section 14 connected to the opposite side of the steam condensation section 11 to the turbine exhaust duct 10. type direct contact condenser.

The turbine exhaust duct 10 is connected above the steam condensing section 11 and extends to flow the turbine exhaust downward. The steam condensing section 11 allows the turbine exhaust from the turbine exhaust duct 10 to flow in, and brings the turbine exhaust into direct contact with the cooling water supplied from the cooling water supply pipe 12, thereby condensing the steam contained in the turbine exhaust. is configured as

The cooling water supply pipe 12 is provided inside the steam condenser 11 and in the y-axis direction. A plurality of spray nozzles 13a to 13c are provided at predetermined intervals in the longitudinal direction (y-axis direction) of the cooling water supply pipe 12, respectively. Here, among the spray nozzles, the one provided in the cooling water supply pipe 12 on the most upstream side in the flow direction is the spray nozzle 13a, and the one provided in the cooling water supply pipe 12 on the most downstream side in the flow direction. is a spray nozzle 13c, and the others are a spray nozzle 13b. In the present embodiment, a row in which such cooling water supply pipes 12 are arranged in three stages in the flow direction of the turbine exhaust inside the steam condenser section 11 (in the following description, these rows will be referred to as pipe rows) is referred to as a turbine exhaust pipe. Two rows of tubes are provided in parallel in a direction perpendicular to the flow direction of the tube, for a total of three rows and two rows of tubes.

As shown in FIG. 3 , the cooling water supply pipe 12 forms flow paths 21 a to 21 c inside the steam condenser 11 . The rows of the cooling water supply pipes 12 are arranged at equal intervals so that the widths of the flow paths 21a to 21c (the widths in the x-axis direction in FIG. 3) are uniform. In addition, the spray nozzle 13a sprays cooling water on the wall surface side of the vapor condensation section 11 near the spray nozzle 13a obliquely upstream and obliquely downstream at an angle of 45 degrees with respect to the flow direction. Spray nozzles 13b and 13c spray cooling water obliquely downstream at an angle of 45 degrees with respect to the flow direction.

Here, the oblique upstream direction means the upstream side from the direction perpendicular to the flow direction, and the oblique downstream direction means the downstream side from the direction perpendicular to the flow direction. In the present embodiment, the oblique upstream direction is the direction of inclination from the x-axis toward the positive z-axis direction, and the oblique downstream direction is the direction of inclination from the x-axis toward the negative z-axis direction. In this embodiment, the direction in which the spray nozzle sprays cooling water is 45 degrees with respect to the flow direction, but this angle does not necessarily have to be 45 degrees.

The gas cooling section 14 is cooling means for cooling the turbine exhaust that has not been condensed inside the steam condensing section 11, and has a rectangular parallelepiped shape in this embodiment. The gas cooling section 14 is connected to the steam condensing section 11 and extends in the z-axis direction so that the turbine exhaust that has flowed in from below flows upward. Cooled turbine exhaust is discharged through a gas outlet 15 .

A cooling water supply pipe (not shown) and a filler 16 are provided inside the gas cooling unit 14 . The packing material 16 is provided upstream of the flow path in the gas cooling section 14 and has a surface area for increasing the contact area with the turbine exhaust passing through the flow path, and has an increased surface area per volume. It is a contact medium having, for example, projections or grooves formed on its surface. The cooling water supply pipe inside the gas cooling unit 14 is provided above the filler 16 and downstream of the gas cooling unit 14, sprays cooling water on the filler 16, and sprinkles the cooling water on the surface of the filler 16. do. When the turbine exhaust passes through the filler 16 , the gas cooling section 14 cools the turbine exhaust through contact between cooling water flowing on the surface of the filler 16 and the turbine exhaust.

In addition, a hot well 17 is provided below the steam condensing section 11 and the gas cooling section 14 in the z-axis direction. The hot well 17 supplies condensed water obtained by condensing turbine exhaust gas from the steam condensing section 11, cooling water sprayed from the cooling water supply pipe 12 in the steam condensing section 11, and cooling water supply in the gas cooling section 14. The cooling water sprayed from the pipe 12 and the cooling water sprayed down from the surface of the filler 16 are stored.

Next, the operation of the direct contact condenser according to this embodiment will be described. In the condenser 1 , the turbine exhaust gas, which is the main steam after performing expansion work in the steam turbine 33 , flows from the turbine exhaust duct 10 into the steam condensing section 11 . The turbine exhaust flowing into the steam condensing section 11 directly contacts the cooling water sprayed from the spray nozzles 13a to 13c of the cooling water supply pipe 12, whereby steam in the turbine exhaust is condensed to become condensed water. This condensed water, together with the cooling water sprayed from the cooling water supply pipe 12, the cooling water sprayed from the cooling water supply pipe 12 in the gas cooling unit 14, and the cooling water flowing down from the surface of the filler 16, After being stored in the tank, it is sent to the injection well.

Here, when the turbine exhaust contains non-condensable gases such as water vapor and carbon dioxide, the non-condensed turbine exhaust containing water vapor and non-condensable gases that are not condensed in the steam condenser 11 is cooled by the steam condenser 11. It flows into the portion 14 , is further cooled there, and is discharged to the outside through the gas discharge port 15 .

In the first embodiment described above, the cooling water supply pipes 12 are arranged in three rows and two rows so that the widths of the flow paths 21a to 21c formed inside the steam condenser 11 by the cooling water supply pipes 12 are uniform. placed in The spray nozzle 13a sprays cooling water on the wall surface side of the vapor condensation section 11 near the spray nozzle 13a in the oblique upstream direction and the oblique downstream direction at an angle of 45 degrees with respect to the flow direction, and the spray nozzles 13b and 13c Cooling water is sprayed obliquely downstream at an angle of 45 degrees with respect to the flow direction.

By providing such a configuration of the first embodiment, not only does the flow velocity of the turbine exhaust in the flow paths 21a to 21c formed between the cooling water supply pipes 12 become uniform, Since the amount of cooling water that is sprayed through the engine becomes more uniform than before, the balance between the cooling water amount and the turbine exhaust amount can be maintained. Therefore, the turbine exhaust is uniformly cooled regardless of which flow path it passes through, and it is possible to prevent the flow from staying inside the steam condenser 11 due to the degree of cooling of the turbine exhaust and the concentration gradient of the non-condensable gas. As a result, the degree of vacuum inside the condenser 1 can be maintained, so that the power generation efficiency of the power plant can be prevented from decreasing.

As a modification of the first embodiment, for example, as shown in FIG. 4, the spray nozzle 13a is arranged at an angle of 45 degrees with respect to the flow direction in the oblique upstream direction and the oblique downstream direction, and the vapor condensing section 11 near the spray nozzle 13a. The spray nozzle 13c sprays cooling water diagonally upstream at an angle of 45 degrees with respect to the flow direction, and the spray nozzle 13b sprays cooling water diagonally downstream at an angle of 45 degrees with respect to the flow direction. A configuration in which cooling water is sprayed in a direction may be employed.

Further, as another modification of the first embodiment, for example, as shown in FIG. 5, the spray nozzle 13a is arranged at an angle of 45 degrees with respect to the flow direction in the oblique upstream and oblique downstream directions and near the spray nozzle 13a. Cooling water may be sprayed on the wall surface side of the portion 11, and the spray nozzles 13b and 13c may spray the cooling water obliquely upstream at an angle of 45 degrees with respect to the flow direction.

According to each modification of the first embodiment shown in FIG. 4 or 5, in addition to the same effect as the first embodiment, the spray nozzle 13b or 13c sprays the cooling water obliquely to the flow direction. By spraying the cooling water in the upstream direction, the heat exchange time between the turbine exhaust and the cooling water can be lengthened, and the cooling performance of the steam condenser 11 can be improved. Therefore, the degree of vacuum inside the condenser 1 can be maintained, and the space in the height direction of the condenser 1 can be shortened.

In the first embodiment or its modification, the spray nozzles 13a to 13c may spray cooling water obliquely upstream or obliquely downstream with respect to the flow direction. The cooling water may not be sprayed upstream or obliquely downstream.

(Second embodiment)
Next, a direct contact condenser according to a second embodiment will be described with reference to the drawings. In the following description, mainly only contents different from the first embodiment will be described, and parts having the same contents as those of the first embodiment or its modification will be given the same reference numerals and detailed description thereof will be given. omitted.

The main differences between this embodiment and the first embodiment are the arrangement of the cooling water supply pipe 12 and the directions in which the spray nozzles 13a to 13c spray the cooling water.

As shown in FIG. 6 , the cooling water supply pipe 12 according to this embodiment forms flow paths 22 a and 22 b inside the steam condenser 11 . The pipe rows of the cooling water supply pipes 12 are arranged in three rows and two rows so that the flow paths 22a and 22b have equal sizes. ) are arranged along the wall surface of the steam condenser 11 on the side of the gas cooling part 14, and the other row (the tube row of the cooling water supply pipe 12 on the right side in FIG. 6) faces each other. 11 are arranged at equidistant positions from both sides of the wall surface.

The spray nozzles 13 a to 13 c spray cooling water diagonally upstream and downstream at an angle of 45 degrees with respect to the flow direction, and on the side opposite to the gas cooling section 14 .

With the configuration of the second embodiment described above, the flow velocity of the turbine exhaust becomes uniform regardless of which of the flow paths 22a and 22b formed between the cooling water supply pipes 12 the turbine exhaust passes. Furthermore, since the flow paths 22a and 22b have the same arrangement relationship between the flow paths and the cooling water supply pipes, the amount of cooling water sprayed onto the turbine exhaust becomes more uniform than in the conventional art. You can keep the balance in quantity. Therefore, the turbine exhaust is uniformly cooled regardless of which flow path it passes through, and it is possible to prevent the flow from staying inside the steam condenser 11 due to the degree of cooling of the turbine exhaust and the concentration gradient of the non-condensable gas. As a result, the degree of vacuum inside the condenser 1 can be maintained, so that the power generation efficiency of the power plant can be prevented from decreasing.

As a modified example of the second embodiment, for example, as shown in FIG. Cooling water may be sprayed on the opposite side, and the spray nozzle 13c may spray cooling water diagonally upstream and vertically at an angle of 45 degrees with respect to the flow direction, and on the side opposite to the gas cooling section 14. FIG.

As another modified example of the second embodiment, for example, as shown in FIG. Cooling water may be sprayed on the opposite side, and the spray nozzles 13b and 13c may spray cooling water diagonally upstream and vertically at an angle of 45 degrees to the flow direction, and on the side opposite to the gas cooling unit 14. good.

According to each modification of the second embodiment shown in FIG. 7 or 8, in addition to the same effect as the second embodiment, the spray nozzle 13b or 13c sprays the cooling water obliquely with respect to the flow direction. By spraying the cooling water upstream or vertically, the heat exchange time between the turbine exhaust and the cooling water can be lengthened, and the cooling performance of the steam condenser 11 can be improved. Therefore, the degree of vacuum inside the condenser 1 can be maintained, and the space in the height direction of the condenser 1 can be shortened.

In the second embodiment or its modification, when the cooling water is sprayed obliquely upstream or obliquely downstream with respect to the flow direction from the spray nozzles 13a to 13c, The cooling water may be sprayed in the downstream direction, and the cooling water may not be sprayed obliquely upstream or obliquely downstream at an angle of 45 degrees with respect to the flow direction.

(Third embodiment)
Next, a direct contact condenser according to a third embodiment will be described with reference to the drawings. In the following description, only the contents that are different from the above-described embodiments and modifications thereof will be mainly described, and the same contents as those of the first and second embodiments and their modifications will be the same. , and detailed description thereof will be omitted.

This embodiment differs from each of the above-described embodiments and modifications thereof in the arrangement of the cooling water supply pipe 12 and the directions in which the spray nozzles 13a to 13c spray the cooling water.

As shown in FIG. 9 , the cooling water supply pipe 12 according to this embodiment forms a flow path 23 inside the steam condenser 11 . The cooling water supply pipes 12 are arranged in three rows and two rows, one of which (the left cooling water supply pipe 12 in FIG. , and another row (the tube row of the cooling water supply pipe 12 on the right side in FIG. 9) is arranged along the wall surface of the steam condenser 11 on the opposite side.

The spray nozzles 13a to 13c spray cooling water diagonally upstream and downstream at an angle of 45 degrees with respect to the flow direction, and toward the flow path 23 side.

With the configuration of the third embodiment described above, when the turbine exhaust passes through one flow path formed between the cooling water supply pipes 12, the cooling water is symmetrically sprayed. Not only is the flow velocity of the turbine exhaust passing through the flow path 23 more uniform than in the past, but also the amount of cooling water sprayed into the flow path 23 is more uniform than in the past, resulting in a balance between the amount of cooling water and the amount of turbine exhaust. can keep Therefore, the turbine exhaust is uniformly cooled, and it is possible to prevent the flow from staying inside the steam condenser 11 due to the degree of cooling of the turbine exhaust and the concentration gradient of the uncondensed gas. As a result, the degree of vacuum inside the condenser 1 can be maintained, so that the power generation efficiency of the power plant can be prevented from decreasing.

As a modification of the third embodiment, for example, as shown in FIG. 10, the spray nozzles 13a and 13b are arranged at an angle of 45 degrees with respect to the flow direction to spray cooling water in the upstream and downstream directions and toward the flow path 23 side. , and the spray nozzle 13c may be configured to spray the cooling water in the oblique upstream direction and the vertical direction at an angle of 45 degrees with respect to the flow direction and in the flow path 23 side.

As a modification of the third embodiment, for example, as shown in FIG. 11, the spray nozzle 13a sprays cooling water toward the flow path 23 diagonally upstream and downstream at an angle of 45 degrees with respect to the flow direction. Alternatively, the spray nozzles 13b and 13c may be configured to spray the cooling water toward the flow path 23 obliquely upstream and vertically at an angle of 45 degrees with respect to the flow direction.

According to each modification of the third embodiment shown in FIG. 10 or 11, in addition to the same effect as the third embodiment, the spray nozzle 13b or 13c sprays the cooling water obliquely with respect to the flow direction. By spraying the cooling water upstream or vertically, the heat exchange time between the turbine exhaust and the cooling water can be lengthened, and the cooling performance of the steam condenser 11 can be improved. Therefore, the degree of vacuum inside the condenser 1 can be maintained, and the space in the height direction of the condenser 1 can be shortened.

In the third embodiment or its modification, when the cooling water is sprayed obliquely upstream or obliquely downstream with respect to the flow direction from the spray nozzles 13a to 13c, The cooling water may be sprayed in the downstream direction, and the cooling water may not be sprayed obliquely upstream or obliquely downstream at an angle of 45 degrees with respect to the flow direction.

While several embodiments of the invention have been described, these embodiments have been presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and modifications can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the scope of the invention described in the claims and equivalents thereof.

DESCRIPTION OF SYMBOLS 1... Condenser, 10... Turbine exhaust duct, 11... Steam condensation part, 12... Cooling water supply pipe, 13a, 13b, 13c... Spray nozzle, 14... Gas cooling part, 15... Gas discharge port, 16... Filler , 17... Hot well, 21a, 21b, 21c, 22a, 22b, 23... Flow path, 30... Geothermal power plant, 31... Gas-liquid separator, 32... Dehumidifier, 33... Steam turbine, 34... Generator

Claims (7)

A downward exhaust type condenser in which a cooling water supply pipe is provided inside a steam condenser section into which turbine exhaust flows,
a plurality of spray nozzles provided in the cooling water supply pipe and arranged in a flow direction of the turbine exhaust;
Among the plurality of spray nozzles, the spray nozzle arranged on the most upstream side with respect to the flow direction of the turbine exhaust is a direct contact spray nozzle that sprays cooling water obliquely upstream with respect to the flow direction of the turbine exhaust. type condenser. 2. The direct contact type according to claim 1, wherein the spray nozzle arranged most downstream with respect to the flow direction of the turbine exhaust sprays cooling water in an oblique upstream direction or a vertical direction with respect to the flow direction of the turbine exhaust. condenser. 2. The direct contact condenser according to claim 1, wherein the spray nozzles other than the most upstream spray nozzle spray cooling water obliquely upstream or perpendicularly to the flow direction of the turbine exhaust. 4. The direct contact condenser according to any one of claims 1 to 3, wherein the plurality of rows of spray nozzles are arranged in parallel in a direction perpendicular to the flow direction of the turbine exhaust gas. 5. The direct contact condenser of claim 4, wherein adjacent rows of spray nozzles are equally spaced. Among the rows of the spray nozzles, one row is arranged along the wall surface of the steam condenser section, and the other row is arranged at equal intervals from the wall surfaces of the steam condenser section facing each other. 4. The direct contact condenser according to 4. 5. The method according to claim 4, wherein one of the rows of the spray nozzles is arranged along the wall surface of the steam condensing section, and the other row is arranged along the wall surface opposite to the wall surface. Direct contact condenser.

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