CN112664273A

CN112664273A - Organic working medium expander rotor

Info

Publication number: CN112664273A
Application number: CN202011576563.7A
Authority: CN
Inventors: 郭擎; 何嘉琪; 邓浩; 刁钟洋; 李鹏春
Original assignee: Chongqing Jiangjin Shipbuilding Industry Co Ltd
Current assignee: Chongqing Jiangjin Shipbuilding Industry Co Ltd
Priority date: 2020-12-28
Filing date: 2020-12-28
Publication date: 2021-04-16
Anticipated expiration: 2040-12-28
Also published as: CN112664273B

Abstract

The invention discloses an organic working medium expander rotor which has good pneumatic isentropic efficiency and reasonable axial force, can better adapt to variable working condition conditions, and has reasonable structure and convenient assembly. A chamber A is separated from the air inlet shell, and static pressure PA is in the chamber; isolating a chamber B, and a static pressure PB in the chamber B; isolating a chamber C, and keeping static pressure PC in the chamber C; isolating a chamber D and keeping static pressure PD in the chamber D; separating a chamber E, and keeping static pressure PE in the chamber E; separating a chamber F and keeping static pressure PF in the chamber F; separating a chamber H, and keeping static pressure PH in the chamber H; isolating a chamber G, and keeping static pressure PG in the chamber G; a gas flow channel M is formed by a gap between the balance gas seal and the balance disc, a gas flow channel N is arranged in the gas inlet shell 1, the minimum cross-sectional area of the gas flow channel M along the gas flowing direction is S1, and the minimum cross-sectional area of the gas flow channel N along the gas flowing direction is S2; PA, PB, PC, PD, PE, PF, PG-PH; (PA-PC) > (PC-PE) > (PE-PH); 7> (PA-PB)/(PB-PC) >5, 4> (PC-PD)/(PD-PE) > 2; 4> (PE-PF)/(PF-PH) > 2; 1.3H/A > S2/S1> H/A, PG < PH +50 KPa.

Description

Organic working medium expander rotor

Technical Field

The invention relates to the technical field of expanders, in particular to an organic working medium expander rotor.

Background

The organic working medium Rankine cycle system is mainly used for recycling low-grade heat energy such as low-temperature waste heat or industrial waste heat, and the organic working medium expansion machine is core equipment of the organic Rankine cycle system. With the promotion of energy-saving and emission-reducing policies, organic working medium expanders are increasingly applied to various industrial enterprises, and through efficient design, emission can be reduced and the investment recovery period can be shortened. Meanwhile, the flow of the waste heat source is changed due to the change of the load generated in a factory, and the pressure at the inlet and the outlet of the expander rotor is caused by the operation under the working condition of frequent start and stop, so that the axial force change is large, and the working condition of the expander rotor is severe. The conventional design improves the isentropic efficiency through a high-reaction design, axial force is easy to be abnormal, the low-reaction design can reduce the axial force of a rotor but has low efficiency, the running state of the rotor is unstable when the pressure change of an inlet and an outlet is large, and the reliable and efficient organic working medium expander rotor can be designed only by accurately controlling the pressure distribution characteristics of all stages of the rotor and the through-flow performance of all gas channels.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides the organic working medium expander rotor which has good pneumatic isentropic efficiency and reasonable axial force, can better adapt to variable working condition conditions, and has reasonable structure and convenient assembly.

The purpose of the invention is realized as follows:

an organic working fluid expander rotor comprising:

an air inlet shell, a main shaft and an exhaust shell;

the mechanical seal, the balance gas seal and the nozzle ring seat are arranged on the air inlet shell;

the first-stage nozzle ring, the second-stage nozzle ring and the last-stage nozzle ring are arranged on the nozzle ring seat;

the balance disc bolt, the balance disc, the first-stage turbine, the second-stage turbine, the last-stage turbine and the spindle nut are arranged on the spindle;

an outlet guide and a final stage air seal are arranged on the exhaust shell;

a chamber A and a static pressure PA in the chamber are separated by the air inlet shell, the nozzle ring seat, the first-stage nozzle ring, the balance gas seal and the balance disc;

a nozzle ring seat, a first-stage nozzle ring and a first-stage turbine separate a chamber B, and static pressure PB in the chamber B;

a chamber C is separated from the nozzle ring seat, the primary turbine and the secondary nozzle ring, and static pressure PC is in the chamber C;

a chamber D is separated by the nozzle ring seat, the secondary nozzle ring and the secondary turbine, and static pressure PD in the chamber D is generated;

a cavity E is separated from the nozzle ring seat, the secondary turbine and the final-stage nozzle ring, and static pressure PE is in the cavity E;

a chamber F is separated by the nozzle ring seat, the final-stage nozzle ring and the final-stage turbine, and static pressure PF is generated in the chamber F;

a final stage turbine, a spindle nut, an outlet guide flow, a final stage air seal, a nozzle ring seat and an exhaust shell separate a chamber H, and the static pressure PH in the chamber H;

a chamber G is separated by the air inlet shell, the mechanical seal, the main shaft, the balance air seal and the balance disc, and static pressure PG is in the chamber G;

a gas flow channel M is formed by a gap between the balance gas seal and the balance disc, a gas flow channel N is arranged in the gas inlet shell 1, the minimum cross-sectional area of the gas flow channel M along the gas flowing direction is S1, and the minimum cross-sectional area of the gas flow channel N along the gas flowing direction is S2;

the gas pressure of each chamber is sequenced as follows: PA, PB, PC, PD, PE, PF, PG-PH;

the change rule of the pressure difference value is (PA-PC) > (PC-PE) > (PE-PH);

the pressure difference ratio change rule is 7> (PA-PB)/(PB-PC) >5, 4> (PC-PD)/(PD-PE) > 2; 4> (PE-PF)/(PF-PH) > 2;

the law of variation of the chamber pressures at S1 and S2 is: PA/PH > S2/S1 is more than or equal to 1.7, PG < PH +50 KPa.

By adopting the technical scheme, the invention ensures that the expander can efficiently operate under different load conditions, ensures that the axial force of the rotor is in a reasonable range, and improves the reliability of the expander.

Through above-mentioned scheme, turbine stage internal pressure descends steadily for inside same turbine stage, turbine and nozzle cascade velocity of flow are balanced relatively promptly, and the highest velocity of flow has the reduction, because loss and velocity of flow have the positive correlation that the square number is greater than 1, reasonable velocity of flow distribution can effectively reduce the loss, under higher expansion ratio, thereby still can effectively avoid because the shock wave that the shock wave formed and arouses loses, makes this level efficiency relatively higher. The pressure difference between the two sides of the first-stage turbine is relatively maximum, the pressure is distributed according to the ratio of 7 (PA-PB)/(PB-PC) >5, the stress on the two sides of the wheel disc can be reduced, the total pressure difference of the two rear stages is relatively small, and the distribution ratio is properly improved, so that the efficiency of the turbine is improved. By adjusting the area ratio of S1 and S2, the balance disc can offset a part of axial force and reduce leakage. When the inlet pressure of the expansion machine rises, the outlet pressure is unchanged, the pressure difference on two sides of each stage of wheel disc rises, the force directed to the right direction on each stage of wheel disc is increased, the force directed to the left direction on the balance disc is correspondingly increased, and the two phases are counteracted to promote the integral axial force of the rotor to return to the normal range. Through the scheme, the aerodynamic loss can be effectively reduced, so that the isentropic efficiency is improved, and the rotor aerodynamic axial force balance is effectively ensured.

Drawings

FIG. 1 is a schematic structural view of the present invention;

FIG. 2 is a schematic view of the chamber distribution of the present invention.

Reference numerals

In the drawing, an air inlet housing 1, a mechanical seal 2, a spindle 3, a balance disk bolt 4, a balance gas seal 5, a balance disk 6, a nozzle ring seat 7, a first-stage nozzle ring 8, a first-stage turbine 9, a secondary nozzle ring 10, a secondary turbine 11, a final-stage nozzle ring 12, a final-stage turbine 13, a spindle nut 14, an outlet guide 15, a final-stage gas seal 16 and an exhaust housing 17.

Detailed Description

As shown in fig. 1, an expander axial force stabilization system comprises a mechanical seal 2, a balance gas seal 5, a nozzle ring seat 7 arranged on an air inlet casing 1, a balance disc bolt 4, a balance disc 6, a first stage turbine 9, a second stage turbine 11, a last stage turbine 13, a spindle nut 14 arranged on a spindle, a 5 outlet flow guide, and a last stage gas seal 16 arranged on an exhaust casing 17; the first-stage nozzle ring 8, the second-stage nozzle ring 10 and the last-stage nozzle ring 12 are mounted on the nozzle ring seat 7.

Referring to fig. 2 in combination with fig. 1, an air inlet casing 1, a nozzle ring seat 7, a first-stage nozzle ring 8, a balance gas seal 5 and a balance disc 6 separate a chamber a and static pressure PA in the chamber; a first-stage turbine 9 of a first-stage nozzle ring 8 of the nozzle ring seat 7 is separated from a chamber B, and static pressure PB in the chamber is obtained; the nozzle ring seat 7, the primary turbine 9 and the secondary nozzle ring 10 separate a chamber C and static pressure PC in the chamber; the nozzle ring seat 7, the secondary nozzle ring 10 and the secondary turbine 11 separate a chamber D and a static pressure PD in the chamber; the nozzle ring seat 7, the secondary turbine 11, the final-stage nozzle ring 12, a separated chamber E and a static pressure PE in the chamber; a chamber F is separated by the nozzle ring seat 7, a final-stage nozzle ring 12 and a final-stage turbine 13, a static pressure PF in the chamber, the final-stage turbine 13, a spindle nut 14, an outlet guide 15, a final-stage air seal 16, the nozzle ring seat 7 and an exhaust shell 17 separate a chamber H and a static pressure PH in the chamber; the air inlet shell 1, the mechanical seal 2, the main shaft 3, the balance air seal 5 and the balance disc 6 separate a chamber G, static pressure PG in the chamber, the balance air seal 5 and a gap between the balance discs 6 form an air flow channel M, and the air flow channel N is positioned in the air inlet shell 1. The minimum cross-sectional area of the passage M in the gas flow direction is S1, and the minimum cross-sectional area of the passage N in the gas flow direction is S2.

Referring to figure two in conjunction with figure one,

the reaction degrees are all larger than 0.1 and are sorted according to the gas pressure of each chamber: PA, PB, PC, PD, PE, PF, PG and PH, so as to improve the pneumatic isentropic efficiency. The change rule of the pressure difference value is (PA-PC) > (PC-PE) > (PE-PH); the pressure between the stages is regularly distributed, and the change rule of the pressure difference ratio is 7> (PA-PB)/(PB-PC) > 5; 4> (PC-PD)/(PD-PE) > 2; 4> (PE-PF)/(PF-PH) >2, reduce the pressure in the first turbine both sides, control the pressure in the second and last turbine both sides in reasonable range, S1 and S2 and cavity pressure change law do: 1.3H/A > S2/S1> H/A, to promote gas mobility in the chamber G and ensure PG < PH +50 KPa.

Finally, it is noted that the above-mentioned preferred embodiments illustrate rather than limit the invention, and that, although the invention has been described in detail with reference to the above-mentioned preferred embodiments, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the scope of the invention as defined by the appended claims.

Claims

1. An organic working medium expander rotor, comprising:

an air inlet shell, a main shaft and an exhaust shell;

an outlet guide and a final stage air seal are arranged on the exhaust shell;

the law of variation of the chamber pressures at S1 and S2 is: 1.3H/A > S2/S1> H/A, PG < PH +50 KPa.