CN112127956B - Steam supply flow equalizing device for sealing shaft end of steam turbine - Google Patents
Steam supply flow equalizing device for sealing shaft end of steam turbine Download PDFInfo
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- CN112127956B CN112127956B CN202010782616.4A CN202010782616A CN112127956B CN 112127956 B CN112127956 B CN 112127956B CN 202010782616 A CN202010782616 A CN 202010782616A CN 112127956 B CN112127956 B CN 112127956B
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
- F01D11/00—Preventing or minimising internal leakage of working-fluid, e.g. between stages
- F01D11/02—Preventing or minimising internal leakage of working-fluid, e.g. between stages by non-contact sealings, e.g. of labyrinth type
- F01D11/04—Preventing or minimising internal leakage of working-fluid, e.g. between stages by non-contact sealings, e.g. of labyrinth type using sealing fluid, e.g. steam
- F01D11/06—Control thereof
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Abstract
The invention relates to a steam supply and flow equalizing device for sealing the shaft end of a steam turbine, which comprises: the low-pressure cylinder shaft seal body cavity, the low-pressure cylinder rotor, the steam seal block and the central control module. According to the steam sealing device, the central control module is arranged, so that the central control module can select the corresponding steam flow according to the load and the backpressure of the unit, the situation that the steam in the low-pressure cylinder shaft seal cavity is leaked due to overhigh pressure in the low-pressure cylinder shaft seal cavity caused by overhigh steam flow when a lower load and a lower backpressure are selected can be effectively prevented, and the steam sealing efficiency of the device is effectively improved. Meanwhile, a steam return chamber is further arranged in the low-pressure cylinder shaft seal body cavity, and the total amount of steam in the low-pressure cylinder shaft seal body cavity can be effectively adjusted by arranging a steam return valve at the port of the steam return chamber and adjusting the opening of the steam return valve, so that the high-efficiency adjustment of the air pressure in the low-pressure cylinder shaft seal body cavity is completed, and the steam seal efficiency of the device is further improved.
Description
Technical Field
The invention relates to the technical field of steam turbine steam seals, in particular to a steam supply and flow equalizing device for steam turbine shaft end sealing.
Background
The steam turbine is a rotary power machine which takes steam as power and converts the heat energy of the steam into mechanical work, and is the most widely applied prime mover in modern thermal power plants. Because the main shaft of the steam turbine must penetrate out of the cylinder, a certain radial gap must be reserved between the main shaft and the cylinder, and the steam pressure in the cylinder is unequal to the external atmospheric pressure, high-pressure steam in the steam turbine must leak outwards through the gap, working medium loss is caused, the operating environment is deteriorated, and a shaft neck or a thrust bearing can be heated to deteriorate lubricating oil; or the external air leaks into the low-pressure end to destroy the vacuum, thereby increasing the load of the steam extraction equipment and reducing the efficiency of the unit. To prevent or reduce this, shaft seals are provided at both ends of the rotor through the cylinder. Although the steam leakage phenomenon can be reduced by the steam turbine shaft seal, the steam leakage cannot be completely eliminated. In order to completely prevent and avoid steam leakage, ensure normal start, stop and operation of a unit, recover the steam leakage, utilize the heat of the steam leakage and reduce the working medium and heat loss of the system, the steam turbine is provided with a shaft seal steam supply system consisting of a shaft seal, a pipeline, a valve and accessory equipment which are connected with the shaft seal.
At present, in the design of low-pressure shaft seal steam supply systems of steam turbines at home and abroad, a shaft seal steam supply pipeline is directly connected with a chamber of a low-pressure cylinder shaft seal body and then is supplied to a steam seal tooth by an annular chamber, so that air at a low-pressure rotor is prevented from leaking into the steam turbine. This sealing method has the following problems:
firstly, a steam supply pipeline is arranged at a 45-degree position on the lower side of a shaft seal body, the steam supply quantity at the bottom of a low-pressure shaft seal cavity is large, the steam supply quantity at the top is small, so that the sealing effect is poor due to uneven steam supply, and part of air can leak into a low-pressure cylinder;
secondly, because different operating modes, high and low back pressure fluctuation can appear when the steam turbine moves, and the distribution condition of steam input flow and steam in the cavity can not be adjusted in a flexible way among the prior art, thereby the steam seal efficiency of steam turbine has been reduced to the air leakage that leads to.
Disclosure of Invention
Therefore, the invention provides a steam supply and flow equalizing device for sealing the shaft end of a steam turbine, which is used for solving the problem of low steam sealing efficiency caused by the fact that the steam flow and the steam distribution cannot be flexibly adjusted according to load, backpressure change and the like in the prior art.
In order to achieve the above object, the present invention provides a steam supply and flow equalizing device for sealing a shaft end of a steam turbine, comprising:
the low-pressure cylinder shaft seal body cavity is internally provided with a steam inlet cavity and a steam return cavity; when the steam turbine operates, steam enters a cavity chamber of the low-pressure cylinder shaft seal through a steam inlet cavity and moves along a specified direction; when the steam in the low-pressure cylinder shaft seal body cavity is higher than a specified value, the central control module controls a valve at the end part of the steam return cavity to be opened so as to output the overflowed steam out of the low-pressure cylinder shaft seal body cavity; a plurality of flow equalizing holes are formed in different positions of the side wall of the steam inlet pipe of the steam inlet chamber, valves are respectively arranged at the ports of the flow equalizing holes, and the steam in the cavity chamber of the low-pressure cylinder shaft seal is uniformly distributed in the cavity chamber of the low-pressure cylinder shaft seal by adjusting the opening and closing of the valves;
a low pressure cylinder rotor disposed inside the low pressure cylinder shaft seal cavity; when the steam turbine operates, the steam moves along the designated direction and impacts fan blades on the low-pressure cylinder rotor, and the fan blades are stressed to rotate so that the steam turbine converts steam energy into kinetic energy;
the steam seal blocks are a plurality of sealing rings, each steam seal block is uniformly arranged on the inner wall of the low-pressure cylinder shaft seal body cavity, the low-pressure cylinder rotor sequentially penetrates through each steam seal block, and steam seal teeth are arranged on the inner wall of each steam seal block and used for dividing the low-pressure cylinder shaft seal body cavity into a plurality of areas to perform steam seal respectively;
and the central control module is arranged on the outer wall of the low-pressure cylinder shaft seal body cavity and is respectively connected with components in the low-pressure cylinder shaft seal body cavity, so that the steam quantity in the low-pressure cylinder shaft seal body cavity is adjusted according to the load and the back pressure of the low-pressure cylinder, and the distribution of the steam in the low-pressure cylinder shaft seal body cavity is adjusted through the opening and closing of the flow equalizing holes when the steam turbine runs, so that the high-efficiency steam seal of the low-pressure cylinder shaft seal body cavity is completed.
Further, each flow equalizing hole is arranged along a straight line, and the straight line is perpendicular to the low-pressure cylinder rotor; the aperture of each flow equalizing hole is different, the aperture of the flow equalizing hole closest to the low-pressure cylinder rotor is the smallest, the aperture of the flow equalizing hole farthest from the low-pressure cylinder rotor is the largest, and the apertures of the flow equalizing holes are gradually increased from near to far according to the distance from the low-pressure cylinder rotor.
Further, the flow equalizing holes include:
the first flow equalizing hole is the smallest in aperture, and a first flow equalizing valve is arranged at the end part of the first flow equalizing hole;
the second flow equalizing hole is arranged at one side, close to the side wall of the cavity, of the first flow equalizing hole, and a second flow equalizing valve is arranged at the end part of the second flow equalizing hole;
the third flow equalizing hole is arranged at one side, close to the side wall of the chamber, of the second flow equalizing hole, and a third flow equalizing valve is arranged at the end part of the third flow equalizing hole;
the fourth flow equalizing hole is arranged on one side, close to the side wall of the cavity, of the third flow equalizing hole, and a fourth flow equalizing valve is arranged at the end part of the fourth flow equalizing hole.
Furthermore, a flow detector connected with the central control module is arranged in a steam inlet pipe of the steam inlet chamber and used for detecting the flow of steam conveyed in the steam inlet pipe; a steam return valve connected with the central control module is arranged at the port of the steam return chamber, and the central control module controls the steam return amount of the steam return chamber by adjusting the opening of the steam return valve; temperature detectors are uniformly distributed at the appointed positions of the low-pressure cylinder shaft seal body cavity and used for detecting the appointed temperature in the low-pressure cylinder shaft seal body cavity so as to judge the distribution condition of steam.
Furthermore, a preset load, a back pressure R0 and a preset steam inlet flow matrix Q0 are arranged in the central control module; for the preset load and back pressure matrixes R0, R0(R1, R2, R3, R4), where R1 is a first preset load and back pressure, R2 is a second preset load and back pressure, R3 is a third preset load and back pressure, and R4 is a fourth preset load and back pressure; for the preset steam inflow rate matrixes Q0 and Q0(Q1, Q2, Q3 and Q4), wherein Q1 is a first preset steam inflow rate, Q2 is a second preset steam inflow rate, Q3 is a third preset steam inflow rate, and Q4 is a fourth preset steam inflow rate;
when the steam turbine is used, the central control module selects corresponding preset steam inlet quantity according to the load and the back pressure of the steam turbine during actual operation:
when the preset load and the back pressure of the low-pressure cylinder rotor are R1, the central control module sets the Q1 as a preset steam inlet amount and monitors the steam flow in the steam inlet chamber;
when the preset load and the back pressure of the low-pressure cylinder rotor are R2, the central control module sets the Q2 as a preset steam inlet amount and monitors the steam flow in the steam inlet chamber;
when the preset load and the back pressure of the low-pressure cylinder rotor are R3, the central control module sets the Q3 as a preset steam inlet amount and monitors the steam flow in the steam inlet chamber;
when the preset load and the back pressure of the low-pressure cylinder rotor are R4, the central control module sets the Q4 to be the preset steam inlet amount and monitors the steam flow in the steam inlet chamber.
Furthermore, a preset steam inlet flow deviation value matrix Qa0 and a preset steam return valve opening matrix K0 are also arranged in the central control module; for the preset steam inlet flow deviation value matrixes Qa0, Qa0(Qa1, Qa2, Qa3, Qa4), wherein Qa1 is a first preset steam inlet flow, Qa2 is a second preset steam inlet flow, Qa3 is a third preset steam inlet flow, and Qa4 is a fourth preset steam inlet flow; for a preset steam return valve opening matrix K0, K0(K1, K2, K3, K4), wherein K1 is a first preset opening of a steam return valve, K2 is a second preset opening of the steam return valve, K3 is a third preset opening of the steam return valve, K4 is a fourth preset opening of the steam return valve, and the opening values are gradually increased in sequence;
when the steam inlet chamber conveys steam into the low-pressure cylinder shaft seal chamber, the flow detector can detect the actual flow Q of the steam in real time, the central control module can compare Q with the corresponding preset steam inlet quantity Qi, i is 1, 2, 3 and 4, and when Q is less than Qi, the central control module controls the corresponding steam conveying device to increase the steam output quantity; when Q is Qi, the central control module does not adjust the loading value; when Q is larger than Qi, the central control module calculates a deviation value Qa between Q and Qi, Qa is Q-Qi, the central control module compares Qa with each parameter in the Qa0 matrix and adjusts the opening of the steam return valve according to the comparison result:
when the Qa is less than or equal to Qa1, the central control module adjusts the opening of the steam return valve to K1;
when Qa is more than Qa1 and less than or equal to Qa2, the opening degree of the steam return valve is adjusted to K2 by the central control module;
when Qa is more than Qa2 and less than or equal to Qa3, the opening degree of the steam return valve is adjusted to K3 by the central control module;
when Qa is more than Qa3 and less than or equal to Qa4, the opening degree of the steam return valve is adjusted to K4 by the central control module;
when Qa is larger than Qa4, the central control module adjusts the opening of the steam return valve to the maximum value and reduces the steam output of the steam delivery device.
Further, the temperature detector includes:
the first temperature detector is arranged at the bottom of the inner wall of the low-pressure cylinder shaft seal body cavity;
the second temperature detector is arranged on the inner wall of the chamber of the low-pressure cylinder shaft seal body, and the included angle between the connecting line of the second temperature detector and the center of the chamber and the connecting line of the first temperature detector and the center of the chamber is 90 degrees;
the third temperature detector is arranged on the inner wall of the chamber of the low-pressure cylinder shaft seal body, and the included angle between the connecting line of the third temperature detector and the center of the chamber and the connecting line of the first temperature detector and the center of the chamber is 135 degrees;
and the fourth temperature detector is arranged on the top of the inner wall of the low-pressure cylinder shaft sealing body cavity.
Further, a preset temperature matrix group T0(T1, T2, T3, T4) is further provided in the central control module, where T1 is a first preset temperature matrix, T2 is a second preset temperature matrix, T3 is a third preset temperature matrix, and T4 is a fourth preset temperature matrix; for the ith preset temperature matrix Ti, i is 1, 2, 3, 4, Ti (Tai, Tbi, Tci, Tdi), wherein Tai is the ith preset temperature of the first temperature detector, Tbi is the ith preset temperature of the second temperature detector, Tci is the ith preset temperature of the third temperature detector, Tdi is the ith preset temperature of the fourth temperature detector, and all the preset temperatures are gradually reduced in sequence;
when the preset load and the back pressure of the low-pressure cylinder rotor are Ri, the central control module selects a corresponding ith preset temperature matrix Ti from a T0 matrix group and adjusts the preset temperature of each temperature detector to a corresponding value in the Ti matrix.
Further, when the steam turbine runs, the central control module can control each temperature detector to detect the temperature of the designated locating point in the cavity of the low-pressure cylinder shaft seal body, the central control module can detect the actual temperature Ta, Tb, Tc and Td of the locating point of each temperature detector in real time, and the central control module compares the detected values with corresponding values in a Ti matrix in sequence:
when Ta is less than Tai, the central control module controls the first flow equalizing valve to be opened;
when Tb is less than Tbi, the central control module controls the second flow equalizing valve to be opened;
when Tc is less than Tci, the central control module controls the third flow equalizing valve to be opened;
and when the Td is less than the Tdi, the central control module controls the fourth current sharing valve to be opened.
Furthermore, the steam inlet chamber and the steam return chamber are respectively arranged on two sides of the low-pressure cylinder shaft seal body chamber, the included angle between the connecting line of the steam inlet chamber and the circle center of the low-pressure cylinder shaft seal body chamber and the horizontal direction is 45 degrees, and the included angle between the connecting line of the steam return chamber and the circle center of the low-pressure cylinder shaft seal body chamber and the horizontal direction is 45 degrees.
Compared with the prior art, the steam sealing device has the advantages that the central control module is arranged, so that the central control module can select the corresponding steam flow according to the low-pressure cylinder load and the back pressure, the situation that the steam in the low-pressure cylinder shaft seal cavity is leaked due to overhigh air pressure in the low-pressure cylinder shaft seal cavity caused by overhigh steam flow when a lower load and a lower back pressure are selected can be effectively prevented, and the steam sealing efficiency of the steam sealing device is effectively improved. Meanwhile, a steam return chamber is further arranged in the low-pressure cylinder shaft seal body cavity, and the total amount of steam in the low-pressure cylinder shaft seal body cavity can be effectively adjusted by arranging a steam return valve at the port of the steam return chamber and adjusting the opening of the steam return valve, so that the high-efficiency adjustment of the air pressure in the low-pressure cylinder shaft seal body cavity is completed, and the steam seal efficiency of the device is further improved.
Furthermore, the steam inlet pipe of the steam inlet chamber is internally provided with a plurality of flow equalizing holes, and the distribution condition of steam in the low-pressure cylinder shaft seal body chamber can be effectively adjusted by controlling the opening and closing of each flow equalizing hole, so that the uniformity of the temperature in the low-pressure cylinder shaft seal body chamber is ensured, the condition of steam leakage in the low-pressure cylinder shaft seal body chamber is effectively prevented, and the steam seal efficiency of the device is further improved.
Furthermore, the aperture of each equalizing hole is gradually increased from near to far according to the distance from the center of the cavity of the low-pressure cylinder shaft seal body, the large-aperture equalizing hole is used at the top of the cavity of the low-pressure cylinder shaft seal body to convey steam, and the small-aperture equalizing hole is used at the bottom of the cavity of the low-pressure cylinder shaft seal body to convey steam, so that the temperature of each point in the cavity of the low-pressure cylinder shaft seal body can be unified quickly, and the steam sealing efficiency of the device is further improved.
Furthermore, a preset unit load, a backpressure matrix R0 and a preset steam inlet flow matrix Q0 are arranged in the central control module, when the steam turbine is used, the central control module selects a corresponding preset steam inlet amount according to the load and the backpressure of the low-pressure cylinder during actual operation of the steam turbine, and the control precision of the central control module on the steam flow in the low-pressure cylinder shaft seal body cavity can be improved by confirming the preset load and the backpressure from the R0 matrix in advance to select the corresponding steam inlet flow from the Q0 connection matrix.
Furthermore, a preset steam inlet flow deviation value matrix Qa0 and a preset steam return valve opening matrix K0 are further arranged in the central control module, when the steam inlet chamber conveys steam into the low-pressure cylinder shaft seal cavity chamber, the flow detector can detect the actual flow Q of the steam in real time, the central control module can compare Q with the corresponding preset steam inlet amount Qi, when Q is larger than Qi, the central control module can calculate the deviation value Qa between Q and Qi, and Qa is Q-Qi, the central control module compares Qa with each parameter in the Qa0 matrix and adjusts the opening of the steam return valve according to the comparison result, and the corresponding steam return valve opening is selected according to the calculated Qa value, so that the central control module can further complete the control precision of the steam flow in the low-pressure cylinder shaft seal cavity chamber.
Furthermore, the temperature detectors are respectively arranged at representative positions on the inner wall of the low-pressure cylinder shaft seal body cavity, and by the arrangement method, the distribution condition of water vapor in the low-pressure cylinder shaft seal body cavity can be analyzed more remarkably when the temperature in the low-pressure cylinder shaft seal body cavity is detected, so that the detection efficiency of the central control module is improved.
Furthermore, the central control module can detect the actual temperatures Ta, Tb, Tc and Td of the positions of the temperature detectors in real time, compares the detection values with corresponding values in the Ti matrix in sequence, opens the corresponding flow equalizing valve according to the comparison result, and can accurately and quickly complete the adjustment of the steam distribution in the cavity of the low-pressure cylinder shaft seal, thereby further improving the steam seal efficiency of the device.
Drawings
FIG. 1 is a schematic structural view of a steam supply and flow equalizing device for shaft end seal of a steam turbine according to the present invention;
FIG. 2 is a partial cross-sectional view of a steam supply flow straightener for a steam turbine shaft end seal in accordance with the present invention.
Detailed Description
In order that the objects and advantages of the invention will be more clearly understood, the invention is further described below with reference to examples; it should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
Preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only for explaining the technical principle of the present invention, and do not limit the scope of the present invention.
It should be noted that in the description of the present invention, the terms of direction or positional relationship indicated by the terms "upper", "lower", "left", "right", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings, which are only for convenience of description, and do not indicate or imply that the device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention.
Furthermore, it should be noted that, in the description of the present invention, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.
Fig. 1 is a schematic structural diagram and a partial sectional view of a steam supply and flow equalizing device for sealing a shaft end of a steam turbine according to the present invention.
The invention relates to a steam supply and flow equalizing device for sealing the shaft end of a steam turbine, which comprises
The low-pressure cylinder shaft seal body cavity 1 is internally provided with a steam inlet cavity 11 and a steam return cavity 12; when the steam turbine operates, steam enters the low-pressure cylinder shaft seal body cavity 1 through the steam inlet cavity 11 and moves along a specified direction to drive the low-pressure cylinder rotor 2 to rotate; when the steam in the low-pressure cylinder shaft seal body cavity 1 is higher than a specified value, the central control module 4 controls a valve at the end part of the steam return cavity to be opened so as to output the overflowed steam out of the low-pressure cylinder shaft seal body cavity 1; a plurality of flow equalizing holes 13 are formed in different positions of the side wall of the steam inlet pipe of the steam inlet chamber 11, valves are respectively arranged at the ports of the flow equalizing holes 13, and the opening and closing of the valves are adjusted to enable steam in the low-pressure cylinder shaft seal chamber to be uniformly distributed in the low-pressure cylinder shaft seal chamber 1.
A low-pressure cylinder rotor 2 disposed inside the low-pressure cylinder shaft seal body chamber 1; when the steam turbine operates, the steam moves along the designated direction and impacts the fan blades on the low-pressure cylinder rotor 2, and the fan blades are stressed to rotate so that the steam turbine converts the steam energy into kinetic energy.
The steam seal blocks 3 are a plurality of sealing rings, each steam seal block 3 is uniformly arranged on the inner wall of the low-pressure cylinder shaft seal body cavity 1, the low-pressure cylinder rotor 2 sequentially penetrates through each steam seal block 3, and steam seal teeth (not shown in the figure) are arranged on the inner wall of each steam seal block 3 and used for dividing the low-pressure cylinder shaft seal body cavity 1 into a plurality of areas to perform steam seal respectively.
And the central control module 4 is arranged on the outer wall of the low-pressure cylinder shaft seal body cavity 1 and is respectively connected with components in the low-pressure cylinder shaft seal body cavity 1, and is used for adjusting the steam quantity in the low-pressure cylinder shaft seal body cavity 1 according to the preset load and back pressure of the low-pressure cylinder rotor 2 and adjusting the distribution of the steam in the low-pressure cylinder shaft seal body cavity 1 through the opening and closing of the flow equalizing holes 13 when the steam turbine runs so as to finish the efficient steam sealing of the low-pressure cylinder shaft seal body cavity 1.
With continued reference to fig. 1 and 2, each of the equalizing holes 13 is arranged along a straight line perpendicular to the low pressure cylinder rotor 2; the aperture of each flow equalizing hole 13 is different, the aperture of the flow equalizing hole 13 closest to the low-pressure cylinder rotor is the smallest, the aperture of the flow equalizing hole 13 farthest from the low-pressure cylinder rotor is the largest, and the apertures of the flow equalizing holes 13 are gradually increased from near to far according to the distance from the low-pressure cylinder rotor.
Specifically, the flow equalizing hole 13 includes:
a first flow equalizing hole 131 with the smallest diameter, and a first flow equalizing valve (not shown) is arranged at the end of the first flow equalizing hole 131;
a second flow equalizing hole 132 arranged at one side of the first flow equalizing hole 131 close to the side wall of the chamber, and a second flow equalizing valve (not shown in the figure) arranged at the end part of the second flow equalizing hole 132;
a third flow equalizing hole 133 arranged on one side of the second flow equalizing hole 132 close to the side wall of the chamber, and a third flow equalizing valve (not shown in the figure) arranged at the end part of the third flow equalizing hole 133;
and a fourth flow equalizing hole 134 is formed at the side of the third flow equalizing hole 133 close to the side wall of the chamber, and a fourth flow equalizing valve (not shown) is arranged at the end of the fourth flow equalizing hole 134.
With reference to fig. 1 and fig. 2, a flow rate detector (not shown) connected to the central control module 4 is disposed in the steam inlet pipe of the steam inlet chamber 11 for detecting the flow rate of the steam conveyed in the steam inlet pipe; a steam return valve (not shown in the figure) connected with the central control module 4 is arranged at the port of the steam return chamber 12, and the central control module 4 controls the steam return amount of the steam return chamber 12 by adjusting the opening degree of the steam return valve; temperature detectors (not shown) are uniformly distributed at the designated positions of the low-pressure cylinder shaft seal body cavity 1 and used for detecting the designated temperature in the low-pressure cylinder shaft seal body cavity 1 so as to judge the distribution condition of steam.
Specifically, a preset load, a backpressure matrix R0 and a preset steam inlet flow matrix Q0 are arranged in the central control module 4; for the preset load and back pressure matrixes R0, R0(R1, R2, R3, R4), where R1 is a first preset load and back pressure, R2 is a second preset load and back pressure, R3 is a third preset load and back pressure, and R4 is a fourth preset load and back pressure; for the preset steam inflow rate matrixes Q0, Q0(Q1, Q2, Q3, Q4), wherein Q1 is a first preset steam inflow rate, Q2 is a second preset steam inflow rate, Q3 is a third preset steam inflow rate, and Q4 is a fourth preset steam inflow rate.
When the steam turbine is used, the central control module 4 selects the corresponding preset steam inlet amount according to the preset load and the back pressure of the low-pressure cylinder rotor 2 when the steam turbine is in actual operation:
when the preset load and the back pressure of the low-pressure cylinder rotor 2 are R1, the central control module sets the Q1 as the preset steam inlet amount and monitors the steam flow in the steam inlet chamber 11;
when the preset load and the back pressure of the low-pressure cylinder rotor 2 are R2, the central control module sets the Q2 as the preset steam inlet amount and monitors the steam flow in the steam inlet chamber 11;
when the preset load and the back pressure of the low-pressure cylinder rotor 2 are R3, the central control module sets the Q3 as the preset steam inlet amount and monitors the steam flow in the steam inlet chamber 11;
when the preset load and the back pressure of the low pressure cylinder rotor 2 are R4, the central control module sets the Q4 as the preset steam inlet amount and monitors the steam flow in the steam inlet chamber 11.
Specifically, a preset steam inlet flow deviation value matrix Qa0 and a preset steam return valve opening matrix K0 are also arranged in the central control module 4; for the preset steam inlet flow deviation value matrixes Qa0, Qa0(Qa1, Qa2, Qa3, Qa4), wherein Qa1 is a first preset steam inlet flow, Qa2 is a second preset steam inlet flow, Qa3 is a third preset steam inlet flow, and Qa4 is a fourth preset steam inlet flow; for the preset steam return valve opening matrix K0, K0(K1, K2, K3, K4), where K1 is the first preset opening of the steam return valve, K2 is the second preset opening of the steam return valve, K3 is the third preset opening of the steam return valve, and K4 is the fourth preset opening of the steam return valve, the opening values are gradually increased in sequence.
When the steam inlet chamber 11 delivers steam into the low-pressure cylinder shaft seal body chamber 1, the flow detector detects the actual flow Q of the steam in real time, the central control module 4 compares Q with the corresponding preset steam inlet quantity Qi, i is 1, 2, 3, 4, and when Q is less than Qi, the central control module 4 controls the corresponding steam delivery device (not shown in the figure) to increase the steam output quantity; when Q is Qi, the central control module 4 does not adjust the loading value; when Q > Qi, the central control module 4 calculates a deviation value Qa between Q and Qi, where Qa is Q-Qi, and the central control module 4 compares Qa with each parameter in the Qa0 matrix and adjusts the opening of the steam return valve according to the comparison result:
when Qa is less than or equal to Qa1, the central control module 4 adjusts the opening of the steam return valve to K1;
when Qa is more than Qa1 and less than or equal to Qa2, the central control module 4 adjusts the opening of the steam return valve to K2;
when Qa is more than Qa2 and less than or equal to Qa3, the central control module 4 adjusts the opening of the steam return valve to K3;
when Qa is more than Qa3 and less than or equal to Qa4, the central control module 4 adjusts the opening of the steam return valve to K4;
when Qa > Qa4, the central control module 4 adjusts the opening of the return steam valve to a maximum value and reduces the steam output of the delivery steam device.
Specifically, the temperature detector includes:
a first temperature detector (not shown in the figure) which is arranged at the bottom of the inner wall of the low-pressure cylinder shaft seal body cavity 1;
the second temperature detector (not shown in the figure) is arranged on the inner wall of the chamber 1 of the low-pressure cylinder shaft seal body, and the included angle between the connecting line of the second temperature detector and the center of the chamber and the connecting line of the first temperature detector and the center of the chamber is 90 degrees;
the third temperature detector (not shown in the figure) is arranged on the inner wall of the chamber 1 of the low-pressure cylinder shaft seal body, and the included angle between the connecting line of the third temperature detector and the center of the chamber and the connecting line of the first temperature detector and the center of the chamber is 135 degrees;
and a fourth temperature detector (not shown in the figure) which is arranged on the top of the inner wall of the low-pressure cylinder shaft sealing body cavity 1.
Specifically, a preset temperature matrix group T0(T1, T2, T3, T4) is further provided in the central control module 4, where T1 is a first preset temperature matrix, T2 is a second preset temperature matrix, T3 is a third preset temperature matrix, and T4 is a fourth preset temperature matrix; for the ith preset temperature matrix Ti, i is 1, 2, 3, 4, Ti (Tai, Tbi, Tci, Tdi), wherein Tai is the ith preset temperature of the first temperature detector, Tbi is the ith preset temperature of the second temperature detector, Tci is the ith preset temperature of the third temperature detector, Tdi is the ith preset temperature of the fourth temperature detector, and all the preset temperatures are gradually reduced in sequence;
when the preset load and the back pressure of the low-pressure cylinder rotor 2 are Ri, the central control module 4 selects a corresponding ith preset temperature matrix Ti from a T0 matrix group and adjusts the preset temperature of each temperature detector to a corresponding value in the Ti matrix.
Specifically, when the steam turbine operates, the central control module 4 controls each temperature detector to detect the temperature of a designated site in the low-pressure cylinder shaft seal body cavity 1, the central control module 4 detects the actual temperature Ta, Tb, Tc, Td of the site where each temperature detector is located in real time, and the central control module 4 compares the detected values with corresponding values in a Ti matrix in sequence:
when Ta is less than Tai, the central control module controls the first flow equalizing valve to be opened;
when Tb is less than Tbi, the central control module controls the second flow equalizing valve to be opened;
when Tc is less than Tci, the central control module controls the third flow equalizing valve to be opened;
and when the Td is less than the Tdi, the central control module controls the fourth current sharing valve to be opened.
With reference to fig. 1 and fig. 2, the steam inlet chamber 11 and the steam return chamber 12 are respectively disposed at two sides of the low-pressure cylinder shaft seal chamber 1, an included angle between a connection line of the steam inlet chamber 11 and a circle center of the low-pressure cylinder shaft seal chamber 1 and a horizontal direction is 45 °, and an included angle between a connection line of the steam return chamber 12 and the circle center of the low-pressure cylinder shaft seal chamber 1 and the horizontal direction is 45 °.
So far, the technical solutions of the present invention have been described in connection with the preferred embodiments shown in the drawings, but it is easily understood by those skilled in the art that the scope of the present invention is obviously not limited to these specific embodiments. Equivalent changes or substitutions of related technical features can be made by those skilled in the art without departing from the principle of the invention, and the technical scheme after the changes or substitutions can fall into the protection scope of the invention.
The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention; various modifications and alterations to this invention will become apparent to those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (9)
1. A steam supply flow equalizing device for sealing the shaft end of a steam turbine is characterized by comprising:
the low-pressure cylinder shaft seal body cavity is internally provided with a steam inlet cavity and a steam return cavity; when the steam turbine operates, steam enters a cavity chamber of the low-pressure cylinder shaft seal through a steam inlet cavity and moves along a specified direction; when the steam in the low-pressure cylinder shaft seal body cavity is higher than a specified value, the central control module controls a valve at the end part of the steam return cavity to be opened so as to output the overflowed steam out of the low-pressure cylinder shaft seal body cavity; a plurality of flow equalizing holes are formed in different positions of the side wall of the steam inlet pipe of the steam inlet chamber, valves are respectively arranged at the ports of the flow equalizing holes, and the steam in the cavity chamber of the low-pressure cylinder shaft seal is uniformly distributed in the cavity chamber of the low-pressure cylinder shaft seal by adjusting the opening and closing of the valves;
a low pressure cylinder rotor disposed inside the low pressure cylinder shaft seal cavity; when the steam turbine operates, the water vapor moves along the designated direction and impacts fan blades on the low-pressure cylinder rotor, and the fan blades are stressed to rotate so that the steam turbine converts steam energy into kinetic energy;
the steam seal blocks are a plurality of sealing rings, each steam seal block is uniformly arranged on the inner wall of the low-pressure cylinder shaft seal body cavity, the low-pressure cylinder rotor sequentially penetrates through each steam seal block, and steam seal teeth are arranged on the inner wall of each steam seal block and used for dividing the low-pressure cylinder shaft seal body cavity into a plurality of areas to perform steam seal respectively;
the central control module is arranged on the outer wall of the low-pressure cylinder shaft seal cavity and is respectively connected with components in the low-pressure cylinder shaft seal cavity, and is used for adjusting the steam quantity in the low-pressure cylinder shaft seal cavity according to the load of a unit and adjusting the distribution of steam in the low-pressure cylinder shaft seal cavity through the opening and closing of the flow equalizing holes when the steam turbine runs so as to finish high-efficiency steam sealing of the low-pressure cylinder shaft seal cavity;
each flow equalizing hole is arranged along a straight line, and the straight line is perpendicular to the low-pressure cylinder rotor; the aperture of each flow equalizing hole is different, the aperture of the flow equalizing hole closest to the low-pressure cylinder rotor is the smallest, the aperture of the flow equalizing hole farthest from the low-pressure cylinder rotor is the largest, and the apertures of the flow equalizing holes are gradually increased from near to far according to the distance from the low-pressure cylinder rotor.
2. The steam supply flow straightener for a steam turbine shaft end seal of claim 1 wherein the flow equalizing bore comprises:
the first flow equalizing hole is the smallest in aperture, and a first flow equalizing valve is arranged at the end part of the first flow equalizing hole;
the second flow equalizing hole is arranged at one side, close to the side wall of the cavity, of the first flow equalizing hole, and a second flow equalizing valve is arranged at the end part of the second flow equalizing hole;
the third flow equalizing hole is arranged at one side, close to the side wall of the chamber, of the second flow equalizing hole, and a third flow equalizing valve is arranged at the end part of the third flow equalizing hole;
the fourth flow equalizing hole is arranged on one side, close to the side wall of the cavity, of the third flow equalizing hole, and a fourth flow equalizing valve is arranged at the end part of the fourth flow equalizing hole.
3. The steam supply and flow equalizing device for the shaft end seal of the steam turbine as claimed in claim 2, wherein a flow detector connected to the central control module is arranged in the steam inlet pipe of the steam inlet chamber to detect the flow of the steam conveyed in the steam inlet pipe; a steam return valve connected with the central control module is arranged at the port of the steam return chamber, and the central control module controls the steam return amount of the steam return chamber by adjusting the opening of the steam return valve; temperature detectors are uniformly distributed at the appointed positions of the low-pressure cylinder shaft seal body cavity and used for detecting the appointed temperature in the low-pressure cylinder shaft seal body cavity so as to judge the distribution condition of steam.
4. The steam supply and flow equalizing device for the shaft end seal of the steam turbine as claimed in claim 3, wherein the central control module is provided with a preset load, a backpressure matrix R0 and a preset steam inflow matrix Q0; for the preset load and back pressure matrixes R0, R0(R1, R2, R3, R4), where R1 is a first preset load and back pressure, R2 is a second preset load and back pressure, R3 is a third preset load and back pressure, and R4 is a fourth preset load and back pressure; for the preset steam inflow rate matrixes Q0 and Q0(Q1, Q2, Q3 and Q4), wherein Q1 is a first preset steam inflow rate, Q2 is a second preset steam inflow rate, Q3 is a third preset steam inflow rate, and Q4 is a fourth preset steam inflow rate;
when the steam turbine is used, the central control module selects corresponding preset steam inlet quantity according to the load and the back pressure of the steam turbine during actual operation:
when the unit load and the backpressure are R1, the central control module sets the Q1 as a preset steam inlet amount and monitors the steam flow in the steam inlet chamber;
when the unit load and the backpressure are R2, the central control module sets the Q2 as a preset steam inlet amount and monitors the steam flow in the steam inlet chamber;
when the unit load and the backpressure are R3, the central control module sets the Q3 as a preset steam inlet amount and monitors the steam flow in the steam inlet chamber;
when the unit load and the backpressure are R4, the central control module sets the Q4 to be the preset steam inlet amount and monitors the steam flow in the steam inlet chamber.
5. The steam supply and flow equalizing device for shaft end sealing of a steam turbine as claimed in claim 4, wherein the central control module further comprises a preset steam inlet flow deviation value matrix Qa0 and a preset steam return valve opening matrix K0; for the preset steam inlet flow deviation value matrixes Qa0, Qa0(Qa1, Qa2, Qa3, Qa4), wherein Qa1 is a first preset steam inlet flow, Qa2 is a second preset steam inlet flow, Qa3 is a third preset steam inlet flow, and Qa4 is a fourth preset steam inlet flow; for a preset steam return valve opening matrix K0, K0(K1, K2, K3, K4), wherein K1 is a first preset opening of a steam return valve, K2 is a second preset opening of the steam return valve, K3 is a third preset opening of the steam return valve, K4 is a fourth preset opening of the steam return valve, and the opening values are gradually increased in sequence;
when the steam inlet chamber conveys steam into the low-pressure cylinder shaft seal chamber, the flow detector can detect the actual flow Q of the steam in real time, the central control module can compare Q with the corresponding preset steam inlet quantity Qi, i =1, 2, 3, 4, and when Q is less than Qi, the central control module controls the corresponding steam conveying device to increase the steam output quantity; when Q = Qi, the central control module does not adjust the loading value; when Q is larger than Qi, the central control module calculates a deviation value Qa between Q and Qi, Qa = Q-Qi, the central control module compares Qa with each parameter in a Qa0 matrix and adjusts the opening of the steam return valve according to the comparison result:
when the Qa is less than or equal to Qa1, the central control module adjusts the opening of the steam return valve to K1;
when Qa is more than Qa1 and less than or equal to Qa2, the opening degree of the steam return valve is adjusted to K2 by the central control module;
when Qa is more than Qa2 and less than or equal to Qa3, the opening degree of the steam return valve is adjusted to K3 by the central control module;
when Qa is more than Qa3 and less than or equal to Qa4, the opening degree of the steam return valve is adjusted to K4 by the central control module;
when Qa is larger than Qa4, the central control module adjusts the opening of the steam return valve to the maximum value and reduces the steam output of the steam delivery device.
6. A steam supply flow straightener for a steam turbine shaft end seal as claimed in claim 3 wherein the temperature sensor comprises:
the first temperature detector is arranged at the bottom of the inner wall of the low-pressure cylinder shaft seal body cavity;
the second temperature detector is arranged on the inner wall of the chamber of the low-pressure cylinder shaft seal body, and the included angle between the connecting line of the second temperature detector and the center of the chamber and the connecting line of the first temperature detector and the center of the chamber is 90 degrees;
the third temperature detector is arranged on the inner wall of the chamber of the low-pressure cylinder shaft seal body, and the included angle between the connecting line of the third temperature detector and the center of the chamber and the connecting line of the first temperature detector and the center of the chamber is 135 degrees;
and the fourth temperature detector is arranged on the top of the inner wall of the low-pressure cylinder shaft sealing body cavity.
7. The steam supply flow equalizing device for the shaft end seal of the steam turbine as claimed in claim 6, wherein a preset temperature matrix set T0(T1, T2, T3, T4) is further provided in the central control module, wherein T1 is a first preset temperature matrix, T2 is a second preset temperature matrix, T3 is a third preset temperature matrix, and T4 is a fourth preset temperature matrix; for the ith preset temperature matrix Ti, i =1, 2, 3, 4, Ti (Tai, Tbi, Tci, Tdi), wherein Tai is the ith preset temperature of the first temperature detector, Tbi is the ith preset temperature of the second temperature detector, Tci is the ith preset temperature of the third temperature detector, Tdi is the ith preset temperature of the fourth temperature detector, and all the preset temperatures are gradually reduced in sequence;
when the load and the back pressure of the low-pressure cylinder rotor are Ri, the central control module selects a corresponding ith preset temperature matrix Ti from a T0 matrix group and adjusts the preset temperature of each temperature detector to a corresponding value in the Ti matrix.
8. The steam supply and flow equalizing device for shaft end seal of steam turbine according to claim 7, wherein when the steam turbine is running, the central control module controls each temperature detector to detect the temperature of the designated locating point in the cavity of the low cylinder shaft seal body, the central control module detects the actual temperature Ta, Tb, Tc, Td of the location point of each temperature detector in real time, and the central control module compares the detected values with corresponding values in the Ti matrix in sequence:
when Ta is less than Tai, the central control module controls the first flow equalizing valve to be opened;
when Tb is less than Tbi, the central control module controls the second flow equalizing valve to be opened;
when Tc is less than Tci, the central control module controls the third flow equalizing valve to be opened;
and when the Td is less than the Tdi, the central control module controls the fourth current sharing valve to be opened.
9. The steam supply and flow equalizing device for steam turbine shaft end seal according to claim 1, wherein the steam inlet chamber and the steam return chamber are respectively disposed at two sides of the low pressure cylinder shaft seal body chamber, and an included angle between a line connecting the centers of the steam inlet chamber and the low pressure cylinder shaft seal body chamber and a horizontal direction is 45 degrees, and an included angle between a line connecting the centers of the steam return chamber and the low pressure cylinder shaft seal body chamber and the horizontal direction is 45 degrees.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010782616.4A CN112127956B (en) | 2020-08-06 | 2020-08-06 | Steam supply flow equalizing device for sealing shaft end of steam turbine |
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| Application Number | Priority Date | Filing Date | Title |
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| CN202010782616.4A CN112127956B (en) | 2020-08-06 | 2020-08-06 | Steam supply flow equalizing device for sealing shaft end of steam turbine |
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| CN112127956A CN112127956A (en) | 2020-12-25 |
| CN112127956B true CN112127956B (en) | 2021-08-10 |
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Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101210500A (en) * | 2006-12-30 | 2008-07-02 | 潘健 | Steam turbine capable of exchanging contact gas and water dual-purpose shaft seal without uncovering jar |
| US8439634B1 (en) * | 2011-01-21 | 2013-05-14 | Florida Turbine Technologies, Inc. | BOAS with cooled sinusoidal shaped grooves |
| CN207194961U (en) * | 2017-09-11 | 2018-04-06 | 广东大唐国际潮州发电有限责任公司 | A kind of turbine shaft seal steam temperature control system |
-
2020
- 2020-08-06 CN CN202010782616.4A patent/CN112127956B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101210500A (en) * | 2006-12-30 | 2008-07-02 | 潘健 | Steam turbine capable of exchanging contact gas and water dual-purpose shaft seal without uncovering jar |
| US8439634B1 (en) * | 2011-01-21 | 2013-05-14 | Florida Turbine Technologies, Inc. | BOAS with cooled sinusoidal shaped grooves |
| CN207194961U (en) * | 2017-09-11 | 2018-04-06 | 广东大唐国际潮州发电有限责任公司 | A kind of turbine shaft seal steam temperature control system |
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| CN112127956A (en) | 2020-12-25 |
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