JPH04132407U - mixed pressure steam turbine - Google Patents

Abstract

(57) [Summary] (with amendments) [Purpose] When high-pressure steam and low-pressure steam are mixed and used as working steam in a mixed-pressure steam turbine, the low-pressure steam is mixed with high-pressure steam without any forced adjustment. to let [Configuration] A turbine casing divided into two parts,
Among these turbine casings, the upper half turbine casing 12 has a high pressure steam inlet, and the lower half turbine casing 13 has a low pressure steam inlet. is connected to the high-pressure steam inlet part and has a Curtiss step part with a part of the passage blocked by a partition, and the turbine rotor covered by the lower half turbine casing has a wall of the low-pressure steam inlet part as a border. It has a rotor blade row 6, 8, which is one of the Curtiss stage sections CSTG, on one side, and a Rato stage section RSTG covered by an outer jacket continuously protruding from the low-pressure steam inlet wall on the other side. A mixing chamber MR for mixing high-pressure steam and low-pressure steam was provided on the exit side of the Ratto stage section.

Description

[Detailed explanation of the idea]

[Purpose of invention]

0001

[Industrial application field]

This idea is useful when high pressure steam and low pressure steam are mixed and used as working steam. , mixed-pressure steam that allows low-pressure steam to mix with high-pressure steam without any forced restrictions. Regarding turbines.

0002

[Conventional technology]

Figure 4 shows a conventionally used mixed pressure steam turbine, with the turbine casing The turbine casing CA is divided into two parts with the axis C as the border, an upper half turbine casing 12 and a lower half turbine casing 12. -bin casing 13, and an upper half turbine casing 12 and a lower half turbine casing 12 on the axis C. It is overlapped with the half turbine casing 13 and covers the turbine rotor R. Ru.

0003 The upper half turbine casing 12 that covers the turbine rotor R has high pressure steam on one side. It has a high pressure steam inlet section 16a that receives air. Connected to this high pressure steam inlet section 16a The stepped section includes nozzles 5 arranged semi-annularly, and rotor blades arranged annularly around the entire circumference of the turbine rotor R. A row 6 of guide blades 7 arranged in a semi-annular shape, and a row 8 of rotor blades arranged annularly in the turbine rotor R. A Curtiss step portion CT is formed.

0004 On the other hand, the stepped portion of the lower half turbine casing 13 that covers the turbine rotor R is , which is partially asymmetrical to the stepped portion of the upper half turbine casing 12, and has a semi-annular shape. The above-mentioned rotor blade row 6 is arranged on one side and the above-mentioned rotor blade row 8 is arranged on the other side with the barrier 6a as a boundary. has been done.

[0005] By the way, the exit side of the rotor blade row 8 is connected to the upper and lower half turbine casings 12 and 13. A mixing chamber MR is opened at the target position, and a low pressure steam input is installed to introduce low pressure steam into this mixing chamber MR. A mouth portion 16b is provided. Also, on the downstream side along the axis C from the mixing chamber MR, , a nozzle 10a and a rotor blade 11 are installed at target positions on the upper and lower half turbine casings 12 and 13. a second stage section SSTG consisting of the nozzle 10b, and a third stage section consisting of the moving blade 11b The TSTGs are arranged in the following order.

[0006] Therefore, in the mixed pressure steam turbine having the above configuration, from the high pressure steam inlet portion 16a Most of the work is done by the nozzle 5 of the Curtiss stage CT, and the high pressure steam 6, the guide vanes 7 and the row of rotor blades 8 change the steam flow and send it out to the downstream side. Also, The high-pressure steam passing through the stage section CT is covered by the lower half turbine casing 13. The steam also flows into rows 6 and 8 of moving blades, but these rows simply stir the steam that has flowed in. There is only one.

[0007] The high-pressure steam that has passed through the Curtiss stage CT reaches the mixing chamber MR, where the The steam mixed with the steam from the pressure steam inlet section 16b is mixed with the steam from the second stage section SSTG and the third stage section SSTG. It passes through the stage section TSTG, and during this time, steam energy is converted into work.

[0008] In this way, a mixed-pressure steam turbine that skillfully uses high-pressure steam and low-pressure steam , utilizes high and low pressure steam energy to the fullest, making a huge contribution to the proportion of small types. I'm trying to gain strength.

[0009]

[Problem that the idea aims to solve]

Generally, in this type of steam turbine, about half of the steam passing through one stage is It is known that the pressure of high-pressure steam decreases to 100 kg/cm.² So, the low pressure steam is 50kg/cm² In the case of It has been experienced that the application of pressurized steam provides desirable work efficiency. For this reason, low If the pressure of the high-pressure steam is low and the pressure difference with the high-pressure steam is more than half, the turbine stage section The low-pressure steam is introduced from an appropriate stage at the rear and mixed with high-pressure steam. Sometimes.

However, for example, when the high pressure vapor pressure is 150 kg/cm ² So, the low pressure vapor pressure is 100 kg/cm ² In the case of conventional mixed-pressure steam turbines, if the energy of the low-pressure steam is used as is, the work efficiency will not increase as much as expected, so the pressure of the low-pressure steam must be forcibly reduced, and the low-pressure There was an inconvenience that the steam pressure could not be utilized as it was.

[0011] Therefore, this idea was based on the above circumstances, and when mixing low pressure steam with high pressure steam, Modified to mix low-pressure steam without adjusting the pressure and obtain high work efficiency. The purpose is to publicize a mixed pressure steam turbine with improved quality. [Structure of the idea]

0012

[Means to solve the problem]

The present invention provides a turbine casing that is divided into two parts. The upper half of the turbine casing has a high pressure steam inlet, and the lower half of the turbine casing has a high pressure steam inlet. The bin casing has a low-pressure steam inlet, which is covered by the upper half of the turbine casing. The turbine rotor is connected to the high-pressure steam inlet and has a part of the vent. The lower half turbine casing has a Curtiss section blocked by a partition. The above-mentioned Curtiss stage is installed on one side of the turbine rotor, which is installed in a A row of rotor blades is placed on one side, and the other side is connected to the low-pressure steam inlet wall and protrudes from the wall. The above-mentioned Curtiss paragraph, Lato paragraph A mixing chamber is formed on the outlet side of the chamber to mix high-pressure steam and low-pressure steam. Ru.

[0013]

[Effect]

According to the above configuration, the high pressure steam flowing from the high pressure steam inlet section to the Curtiss stage section is Some of the ports in the Curtiss section are blocked by partitions, so the flow rate should be restricted. However, the velocity energy increases. For this reason, the nozzle in the Curtiss step part , vapor expansion can be performed based on high velocity energy, so high work can be done. The vapor pressure also drops significantly.

[0014] On the other hand, when the low pressure steam from the low pressure steam inlet passes through the ratchet stage, the nozzle The work and vapor pressure drop are those of the Curtiss stage. It's not expensive compared to that. In this case, the falling steam passing through the row of rotor blades in the Rato stage section and the The high-pressure steam passing through the row of rotor blades in the Curtiss section is heated to approximately equal pressure. Adjust the nozzle installation in the paragraph section, for example, select the throat area between each nozzle to a preferable value. It has been done.

[0015] Therefore, the pressure of the low-pressure steam passing through the row of rotor blades in the Rato stage section and the above Curtiss The pressure of the high-pressure steam that passes through the row of rotor blades in the stage section is approximately equal to the pressure that flows into the mixing chamber. , the work in the rear stage after the mixing chamber is doubled, and high work efficiency can be obtained.

[0016]

【Example】

An embodiment of the mixed pressure steam turbine according to this invention will be explained below with reference to the drawings. Ru.

FIG. 1 is a schematic diagram of a mixed pressure steam turbine according to this invention, showing an upper half turbine casing 12 and a lower turbine casing 13. The upper half-turbine casing 12 and the lower half-turbine casing 13 are superimposed on the transverse axis C ₁ as shown in FIG. 2 and are arranged along the longitudinal axis C ₂ of the turbine rotor R in FIG. It is a flowing type. Further, a high pressure steam inlet section 16 for receiving high pressure steam is provided on one side of the upper half turbine casing 12, and a low pressure steam inlet section 17 is also provided in the lower half turbine casing 13 asymmetrically with the high pressure steam inlet section 16. has been established.

[0018] The turbine rotor R covered by the upper half turbine casing 12 has a high From the pressure steam inlet 16, the nozzle 5, the rotor blade row 6, the guide blade 7, and the rotor blade row 8 are arranged in order. A Curtiss paragraph part CSTG is arranged. On the other hand, the lower half turbine casing 1 3, the turbine rotor R covered with On the other side of the rotor blade row 6, a Ratau step section RSTG consisting of a nozzle 9 and a rotor blade row 8 is arranged. has been done. Here, the arrangement of the Rato paragraph section RSTG and the Curtis paragraph section CSTG As shown in FIG. 3, the nozzle 5 of the Curtiss stage part CSTG is It is arranged partially in an annular shape with respect to the data R, and the rest is closed off by a partition 5a. Further, the rotor blade row 6 is installed in a ring shape around the entire circumference of the turbine rotor R. other On the other hand, the nozzle of the Rato step section RSTG with respect to the guide vane 7 of the Curtis step section CSTG. As for the arrangement relationship with 9, as shown in the figure, it is covered and isolated by the outer cover 7a, and in this way, High-pressure steam H and low-pressure steam L flow separately from each other, and in the next rotor blade row 8, the Curtiss stage The row of rotor blades may be common between the drop section CSTG and the ratou section section RSTG. flows as a parallel flow.

As shown in FIG. 1, a mixing chamber MR for mixing high-pressure steam H and low-pressure steam L is provided on the outlet side of the rotor blade row 8 common to the Curtiss stage section CSTG and the Rato stage section RSTG. It is formed as a ring around the entire circumference of the rotor R. Further, on the exit side of the mixing chamber MR, a second stage section SSTG consisting of a nozzle row 10a arranged annularly along the longitudinal axis _C2 of the turbine rotor R, a rotor blade row 11a, and an annularly arranged nozzle row 10b. , a third stage section TSTG consisting of a rotor blade row 11b is provided.

[0020] Therefore, in the above configuration, the high pressure steam H from the high pressure steam inlet section 16 is While passing through the nozzle 5 of the steam stage part CSTG, the steam expands and obtains high work, and the steam pressure It flows to the next rotor blade row 6 with a significant decrease in the amount of water. Here, the lower half turbine casing A small amount of high-pressure steam H also flows through the row of rotor blades 6 covered by the rotor blades 13, but here the steam is It only stirs the air. Then, it is covered with the upper half turbine casing 12. The high-pressure steam H leaving the rotor blade row 6 passes through the guide blades 7 to the Curtiss stage section CSTG and the ratchet. It flows to the rotor blade row 8 which is commonly handled in the stage section RSTG.

[0021] On the other hand, the low-pressure steam L from the low-pressure steam inlet section 17 is sent to the nozzle of the Rato stage section RSTG. Although the work is done by steam expansion while passing through Le 9, the work done by the Curtiss Paragraph Section CSTG is not as great. It's not expensive. In this case, when the low-pressure steam L that has passed through the nozzle 9 flows to the rotor blade row 8, The vapor pressure of the high-pressure steam H passing through the rotor blade row 8 of the Curtiss stage section CSTG is approximately equal to that of the above-mentioned Curtiss stage section CSTG. The throat area of each nozzle 9 of the Ratau step section RSTG is preferably set so that the It has been selected to have a high value. Therefore, in the mixed pressure steam turbine according to this invention, As shown in 3, as common to Curtiss paragraph part CSTG and Ratto paragraph part RSTG. The high-pressure steam H and low-pressure steam L passing through the rotor blade row 8 are both at approximately equal pressure. Since it flows into the mixing chamber MR as a current, the pressure of the low-pressure steam L is forcedly reduced, for example, the steam is adjusted. There is no need for unnecessary throttling by valves, and the pressure energy held by the low-pressure steam L is released. It can be used everywhere.

[0022] In this way, the pressure energy possessed by the low-pressure steam L can be fully utilized while reducing the The pressure steam L and the high pressure steam H have almost equal pressure and join together in the mixing chamber MR, and are then transferred to the second stage. This kind of type One can get high work for its relatively small proportions.

[0023]

[Effect of the idea]

As explained above, the mixed pressure steam turbine according to this invention has an upper half turbine. A longitudinal axis of a turbine rotor covered by a casing and a lower turbine casing half. Different paragraphs are formed in the upper and lower halves of the line to significantly reduce the pressure of high-pressure steam, resulting in low The pressure of the high-pressure steam is brought to almost the same pressure as the high-pressure steam without significantly reducing the pressure, and the steam is combined in the mixing chamber. Because of this, high-pressure steam and low-pressure steam can be used without waste, and high output can be obtained. be able to.

[Brief explanation of drawings]

FIG. 1 is a schematic side sectional view showing an embodiment of a mixed pressure steam turbine according to the invention.

FIG. 2 is a cross-sectional view taken along line II-II in FIG. 1 and viewed from the arrow direction.

FIG. 3 is a developed plan view showing the relationship between the Curtiss stepped portion and the Ratto stepped portion.

FIG. 4 is a schematic side sectional view showing an example of a conventional mixed pressure steam turbine.

[Explanation of symbols]

5, 9... Nozzle, 6, 8... Moving blade row, 7... Guide vane, 12...
Upper half turbine casing, 13...Lower half turbine casing, MR...Mixing chamber, CSTG...Curtis stage section, R
STG...Rato stage section, R...turbine rotor.

Claims (1)

[Scope of utility model registration request] Claim 1: A turbine casing divided into two parts, of which an upper half turbine casing has a high pressure steam inlet, a lower half turbine casing has a low pressure steam inlet, and the upper half turbine casing has a high pressure steam inlet. The turbine rotor, which is covered by the half turbine casing, is connected to the high-pressure steam inlet section and has a Curtiss step part in which the passage is partially blocked by a partition, while the turbine rotor is covered by the lower half turbine casing. The turbine rotor is equipped with a rotor blade row, which is one of the above-mentioned Curtiss stages, on one side of the low-pressure steam inlet wall, and on the other side, an outer sheath extending continuously from the low-pressure steam inlet wall. With a covered ratot paragraph section,
A mixed-pressure steam turbine characterized in that a mixing chamber for mixing high-pressure steam and low-pressure steam is formed on the outlet side of the Curtiss stage section and the Ratto stage section.