Drainage system

Abstract

To provide a drainage system that can more reliably cool the lubricating oil. [Solution] The drainage system comprises a gas turbine 1 installed at a drainage pump station 100, an oil pump 2 driven by the gas turbine 1 to supply lubricating oil to the gas turbine 1, a water pump 3 driven by the gas turbine 1 to supply water from one of the internal water side and the external water side to the other of the internal water side and the external water side, a first oil cooler 4 for cooling the lubricating oil, a second oil cooler 5 connected in parallel with the first oil cooler 4 for cooling the lubricating oil, and a switching unit 6 for switching the destination of the lubricating oil flow between the first oil cooler 4 and the second oil cooler 5.

Description

Technical Field

[0001] The present invention relates to a drainage system.

Background Art

[0002] A gas turbine, which is a type of internal combustion engine, rotates a turbine with gas compressed by a compressor and outputs the rotational force of the turbine. Lubricating oil is supplied to the gas turbine to reduce the frictional force and frictional heat generated by the rotation of the compressor and the turbine. Since the lubricating oil is heated by frictional heat, Patent Document 1 discloses a lubricating oil supply device for cooling the lubricating oil. The lubricating oil supply device cools the lubricating oil by introducing outside air through an air supply duct by the rotation of a centrifugal fan configured to be interlocked with the rotation of the gas turbine and causing heat exchange between the outside air and the lubricating oil.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the gas turbine, when the centrifugal fan stops due to a failure or the like, the lubricating oil cannot be cooled.

[0005] An object of the present invention is to provide a drainage system that can more reliably cool lubricating oil.

Means for Solving the Problems

[0006] One aspect of the present invention provides a drainage system comprising: a gas turbine installed in a drainage pumping station; an oil pump driven by the gas turbine to supply lubricating oil to the gas turbine; a water pump driven by the gas turbine to supply water from one of the internal water side and the external water side to the other of the internal water side and the external water side; a first oil cooler for cooling the lubricating oil; a second oil cooler connected in parallel with the first oil cooler for cooling the lubricating oil; and a switching unit for switching the destination of the lubricating oil between the first oil cooler and the second oil cooler.

[0007] According to the above configuration, since there are two coolers (a first oil cooler and a second oil cooler) connected in parallel as devices for cooling the lubricating oil, even if one of the first and second oil coolers is unable to cool the lubricating oil, the other can still cool it. Therefore, the lubricating oil can be cooled more reliably than in a configuration that has only one of the first and second oil coolers.

[0008] The first oil cooler includes a first oil heat exchanger, an electric motor powered by an external power source, and a fan driven by the electric motor to blow air onto the first oil heat exchanger. The second oil cooler may include a second oil heat exchanger that causes the water and the lubricating oil to exchange heat with each other.

[0009] According to the above configuration, even if, for example, power to the electric motor from an external power source is cut off due to a power outage or the like, and the fan of the first oil cooler does not operate, water is sent to the second oil cooler by a water pump driven by a gas turbine. As a result, the lubricating oil is cooled by switching the destination of the lubricating oil to the second oil cooler.

[0010] The switching unit may configure the lubricating oil to flow to the first oil cooler while power is supplied from the external power source, and to flow to the second oil cooler while the power supply from the external power source is stopped.

[0011] According to the above configuration, even if the power supply from an external power source is cut off and the fan of the first oil cooler does not operate, water is sent to the second oil cooler by a water pump driven by a gas turbine. Therefore, by switching the destination of the lubricating oil to the second oil cooler, the lubricating oil is cooled.

[0012] The switching unit may direct the lubricating oil to the first oil cooler while power is supplied from the external power source, and may direct the lubricating oil to the second oil cooler if it detects an abnormality in the external power source.

[0013] According to the above configuration, even if an abnormality in the external power supply is detected and the fan of the first oil cooler does not operate, water is sent to the second oil cooler by a water pump driven by a gas turbine. Therefore, by switching the destination of the lubricating oil to the second oil cooler, the lubricating oil is cooled.

[0014] The lubricating oil passage through which the lubricating oil flows includes a first passage to which the first oil cooler is connected, and a second passage that branches off from the first passage to bypass the first oil cooler and merges with the first passage, and to which the second oil cooler is connected. The switching unit is a three-way valve, and the three-way valve may be located at the branching point where the second passage branches off from the first passage.

[0015] According to the above configuration, the direction of lubricating oil flow can be easily switched using a simple three-way valve.

[0016] The second oil heat exchanger may be immersed in the flow path connecting the internal water side and the external water side.

[0017] According to the above configuration, the second oil heat exchanger only needs to be immersed in the flow path connecting the internal water side and the external water side, thus simplifying the overall structure. [Effects of the Invention]

[0018] According to the present invention, a drainage system that can more reliably cool the lubricating oil can be provided.

Brief Description of the Drawings

[0019] [Figure 1] Schematic configuration diagram of the drainage system according to the first embodiment. [Figure 2] Schematic diagram of the gas turbine shown in FIG. 1. [Figure 3A] Schematic diagram showing the flow of lubricating oil in the first state of the drainage system shown in FIG. 1. [Figure 3B] Schematic diagram showing the flow of lubricating oil in the second state of the drainage system shown in FIG. 1. [Figure 4] Schematic configuration diagram of the drainage system according to the second embodiment.

Modes for Carrying Out the Invention

[0020] Hereinafter, embodiments will be described with reference to the drawings. In addition, the same or corresponding elements are denoted by the same reference numerals throughout the drawings, and duplicate detailed descriptions are omitted.

[0021] (First Embodiment) As shown in FIG. 1, the drainage system 10 is applied to a drainage airport 100 that drains water outside the levee (hereinafter referred to as external water) when the water level of the water inside the levee (hereinafter referred to as internal water) rises due to rainfall, sewage drainage, flooding of rivers, etc.

[0022] The drainage system 10 includes a gas turbine 1, an oil pump 2, a water pump 3, a first oil cooler 4, a second oil cooler 5, a three-way valve 6 (an example of a switching unit), a control unit 7, a lubricating oil flow path L1, and a water flow path L2. The control unit 7 is composed of a CPU (Central Processing Unit) or MPU (Micro Processing Unit) that realizes a predetermined function in cooperation with software, and controls each part of the drainage system 10 such as the gas turbine 1.

[0023] The gas turbine 1 is installed at the drainage pump station 100. As shown in Figure 2, the gas turbine 1 includes a package 11, a compressor 12 that compresses gas drawn in from outside the package 11 through an air intake (not shown) formed in the package 11, a combustor 13 that burns the compressed, high-pressure gas, a turbine 14 that is rotationally driven by the high-temperature, high-pressure gas that has been burned, and a first reduction gear 15 and a second reduction gear 16 that reduce the rotational speed output from the turbine 14. Although Figure 2 shows a single-shaft gas turbine 1, the gas turbine 1 may also be a double-shaft gas turbine.

[0024] As shown in Figure 1, the oil pump 2 is driven by the gas turbine 1 via the first reduction gear 15 to supply lubricating oil to the gas turbine 1. The oil pump 2 has a first pump rotating shaft (not shown) which is rotated by power transmitted from the gas turbine 1 via the first reduction gear 15, and a first impeller (not shown) which rotates together with the first pump rotating shaft. The lubricating oil is supplied to the bearings of the turbine 14 via the lubricating oil passage L1 to reduce frictional force and frictional heat generated between the bearings (not shown) that rotatably support the rotating shaft (not shown) of the turbine 14 and the rotating shaft of the turbine 14.

[0025] The lubrication oil passage L1 includes a first oil passage L11 (an example of the first passage) connecting the gas turbine 1 and the first oil cooler 4, and a second oil passage L12 (an example of the second passage) connecting the gas turbine 1 and the second oil cooler 5 so as to bypass the first oil cooler 4.

[0026] The first oil passage L11 includes a first oil supply passage L11a through which lubricating oil flows from the gas turbine 1 to the first oil cooler 4, and a first oil return passage L11b through which lubricating oil flows from the first oil cooler 4 to the gas turbine 1.

[0027] The second oil passage L12 branches off from a first position P1 (branching point) downstream of the oil pump 2 in the first oil supply passage L11a and merges with the first oil return passage L11b. The second oil passage L12 includes a second oil supply passage L12a through which lubricating oil flows toward the second oil cooler 5, and a second oil return passage L12b that merges with the first oil return passage L11b at a second position P2 (merging point) and through which lubricating oil flows toward the gas turbine 1 from the second oil cooler 5.

[0028] The water pump 3 is driven by the gas turbine 1 to send water from the internal water side to the external water side. The water pump 3 has a second pump rotating shaft 31 which is rotated by power transmitted from the gas turbine 1 via a second reduction gear 16, and a second impeller 32 which rotates together with the second pump rotating shaft 31. The second impeller 32 is positioned (immersed) in the drainage channel L3 that connects the inside of the embankment (internal water side) and the outside of the embankment (external water side) and rotates there. As a result, water flows from the internal water side to the external water side through the drainage channel L3 and into the water channel L2.

[0029] The water channel L2 includes a first water channel L21 through which water flows from the drainage channel L3 to the second oil cooler 5, and a second water channel L22 through which water flows from the second oil cooler 5 to the drainage channel L3. The water flowing through the first water channel L21 branches off from the drainage channel L3 at a third position P3 downstream of the position where the second impeller 32 is located in the direction of flow of the water flowing through the drainage channel L3. The water flowing through the second water channel L22 merges with the drainage channel L3 at a fourth position P4 downstream of the third position P3 in the direction of flow of the water flowing through the drainage channel L3.

[0030] The first oil cooler 4 is a cooler for cooling lubricating oil. The first oil cooler 4 includes a first oil heat exchanger 41, an electric motor 42 that operates on power supplied from an external power source E, and a fan 43 that is driven by the electric motor 42 to blow air onto the first oil heat exchanger 41. The first oil heat exchanger 41 is an air-cooled heat exchanger that exchanges heat between the lubricating oil and the outside air blown in by the fan 43. The operation of the electric motor 42 is controlled by the control unit 7. The fan 43 is connected to the output shaft of the electric motor 42 and rotates about an axis along the output shaft.

[0031] The second oil cooler 5 is connected in parallel with the first oil cooler 4 and is a cooler for cooling the lubricating oil. The second oil cooler 5 has a second oil heat exchanger 51 that exchanges heat between water and lubricating oil. The second oil heat exchanger 51 is a water-cooled heat exchanger. In the second oil cooler 5, the lubricating oil exchanges heat with water drawn from the internal water side, whose temperature changes with the ambient temperature. For this reason, the temperature of the lubricating oil is lowered more easily by cooling it with the first oil cooler 4 than by cooling it with the second oil cooler 5.

[0032] The three-way valve 6 is positioned at the first position P1 where the second oil passage L12 branches off from the first oil passage L11. The three-way valve 6 switches the destination of the lubricating oil between the first oil cooler 4 and the second oil cooler 5. In other words, the lubricating oil, which has been heated by absorbing frictional heat in the gas turbine 1, is cooled in either the first oil cooler 4 or the second oil cooler 5.

[0033] The three-way valve 6 is an electromagnetic directional control valve that includes a solenoid and an elastic member (spring) that biases the solenoid, and changes its position between a first position and a second position.

[0034] As shown in Figure 3A, in the first state (when energized), when power is supplied to the drainage pump station 100 (i.e., the three-way valve 6) from an external power source E, the three-way valve 6 assumes a first position in which the lubricating oil flows to the first oil cooler 4. As a result, the lubricating oil passes through the first oil cooler 4 and is cooled by heat exchange with the outside air blown by the fan 43.

[0035] On the other hand, as shown in Figure 3B, in the second state (when power is not supplied), when power is not supplied to the drainage pump station 100 from the external power source E due to a power outage or other reasons, and the power supply is stopped (power is cut off), the three-way valve 6 assumes a second position, where the destination of the lubricating oil is the second oil cooler 5, due to the biasing force (spring return) of the elastic member. As a result, the lubricating oil passes through the second oil cooler 5 and is cooled by heat exchange with water. In other words, while power is supplied from the external power source E, the three-way valve 6 directs the lubricating oil to the first oil cooler 4, and while the power supply from the external power source E is stopped, it directs the lubricating oil to the second oil cooler 5. When power is restored, the three-way valve 6 changes its position from the second position to the first position (returns to its original position).

[0036] (Effects of the first embodiment) As described above, according to the embodiment, the drainage system 10 has two coolers (first oil cooler 4 and second oil cooler 5) connected in parallel as devices for cooling the lubricating oil. Therefore, even if one of the first oil cooler 4 and the second oil cooler 5 is unable to cool the lubricating oil, the other can still cool it. Consequently, the lubricating oil can be cooled more reliably than in a configuration that has only one of the first oil cooler 4 and the second oil cooler 5.

[0037] Furthermore, according to the above embodiment, even in a second state (when power is not supplied) where power is not supplied to the drainage pump station 100 from an external power source E due to a power outage or other reasons, and the power supply is stopped (power is cut off), that is, when power from the external power source E to the electric motor 42 is stopped and the fan 43 of the first oil cooler 4 does not operate, water (drainage) is sent to the second oil cooler 5 by the water pump 3 driven by the gas turbine 1, and the lubricating oil is cooled.

[0038] Furthermore, according to the above embodiment, the destination of the lubricating oil can be easily switched to the first oil cooler 4 or the second oil cooler 5 with a simple configuration that only requires arranging the three-way valve 6 at the first position P1.

[0039] (Second Embodiment) Next, with reference to Figure 4, the drainage system 10 according to the second embodiment will be described. In the second embodiment, the location of the second oil cooler 5 differs from that of the first embodiment.

[0040] As shown in Figure 4, in the second embodiment, the second oil cooler 5 is immersed in the drainage channel L3 (an example of a flow path connecting the internal water side and the external water side). This allows the drainage system 10 to omit the water flow path L2 and simplify its configuration.

[0041] (modified version) In the above embodiment, the second state was described as a state in which the supply of power from the external power source E to the drainage pump station 100 is stopped. However, the second state may also be a state in which an abnormality in the external power source E is detected by the control unit 7. An abnormality in the external power source E is, for example, a state in which the external power source E is overloaded. When the control unit 7 detects an abnormality in the external power source E, it outputs an alarm signal indicating the abnormality of the external power source E. When the alarm signal output by the control unit 7 is input to the three-way valve 6, the three-way valve 6 stops supplying power to the solenoid (cuts off the power). As a result, the posture of the three-way valve 6 becomes the second posture, and the destination of the lubricating oil becomes the second oil cooler 5. If the power supplied to the three-way valve 6 is supplied from a power source other than the external power source E, for example, if an overcurrent occurs in the external power source E and the output power of the external power source E is cut off by the protection circuit of the external power source E, the control unit 7 may stop supplying power to the solenoid of the three-way valve 6.

[0042] In the above embodiment, a three-way valve 6 was described as an example of a switching unit, but the switching unit is not limited to a three-way valve 6, and may be, for example, a combination of two two-way valves. When the switching unit is composed of a combination of two two-way valves, one of the two two-way valves is located in the first oil passage L11 downstream of the first position P1, and the other is located in the second oil passage L12 downstream of the first position P1. Furthermore, the three-way valve 6 is not limited to an electromagnetic valve, but may be an electrically operated valve, or any other valve as appropriate.

[0043] Furthermore, in the above embodiment, the three-way valve 6 is configured to change its orientation according to the state of the power input, but the three-way valve 6 may also be configured to change its orientation according to a control signal input from the control unit 7.

[0044] In the above embodiment, the case in which the water pump 3 sends water from the internal water side to the external water side was described, but the water pump 3 may also send water from the external water side to the internal water side. [Explanation of Symbols]

[0045] 1 Gas Turbine 2. Oil pump 3 Water pump 4 No. 1 oil cooler 5 2nd oil cooler 6. Three-way valve (an example of a switching mechanism) 7 Control Unit 10 Drainage System 11 packages 12 Compressor 13 Combustor 14 Turbine 15 1st reducer 16 2nd reducer 31. Second pump rotating shaft 32. Second impeller 41 1st oil heat exchanger 42 Electric motor 43 Fans 51 2nd oil heat exchanger 100 Drainage pump station E External power supply L1 Lubricant flow path L2 water flow path L3 drainage channel L11 1st oil flow path L11a First oil supply channel L11b 1st oil return flow path L12 2nd oil flow path L12a Second oil supply channel L12b 2nd oil return flow path L21 1st water flow path L22 2nd water flow path P1 1st position P2, Position 2 P3, Position 3 P4, Position 4

Claims

1. A gas turbine to be installed at a drainage pumping station, An oil pump, driven by the gas turbine, supplies lubricating oil to the gas turbine. A water pump, driven by the aforementioned gas turbine, sends water from one of the internal water side and the external water side to the other of the internal water side and the external water side. A first oil cooler for cooling the lubricating oil, A second oil cooler is connected in parallel with the first oil cooler for cooling the lubricating oil, A switching unit that switches the destination of the lubricating oil between the first oil cooler and the second oil cooler, A drainage system equipped with the following features.

2. The first oil cooler comprises a first oil heat exchanger, an electric motor powered by an external power source, and a fan driven by the electric motor to blow air onto the first oil heat exchanger. The drainage system according to claim 1, wherein the second oil cooler includes a second oil heat exchanger that causes the water and the lubricating oil to exchange heat with each other.

3. The drainage system according to claim 2, wherein the switching unit directs the lubricating oil to the first oil cooler while power is supplied from the external power source, and directs the lubricating oil to the second oil cooler while the power supply from the external power source is stopped.

4. The drainage system according to claim 2, wherein the switching unit sets the destination of the lubricating oil to the first oil cooler while power is supplied from the external power source, and sets the destination of the lubricating oil to the second oil cooler when it detects an abnormality in the external power source.

5. The lubricating oil passage through which the lubricating oil flows includes a first passage to which the first oil cooler is connected, and a second passage that branches off from the first passage to bypass the first oil cooler and merges with the first passage, and to which the second oil cooler is connected. The switching section is a three-way valve, The drainage system according to claim 3 or 4, wherein the three-way valve is positioned at the branching point where the second flow path branches off from the first flow path.

6. The drainage system according to claim 2, wherein the second oil heat exchanger is immersed in a flow path connecting the internal water side and the external water side.

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