CN112664273B

CN112664273B - Organic working medium expander rotor

Info

Publication number: CN112664273B
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: 2023-05-02
Anticipated expiration: 2040-12-28
Also published as: CN112664273A

Abstract

The invention discloses a rotor of an organic working medium expansion machine, which has good pneumatic isentropic efficiency and reasonable axial force, can be well adapted to variable working conditions, and is reasonable in structure and convenient to assemble. A chamber A is separated from the air inlet shell, and the static pressure PA in the chamber is higher than the static pressure PA in the chamber; separating a chamber B, wherein the static pressure PB in the chamber B; separating a chamber C, wherein the static pressure PC in the chamber C; separating a chamber D, wherein the static pressure PD in the chamber D; separating a chamber E, wherein the static pressure PE in the chamber E is generated; separating a chamber F, wherein the static pressure PF in the chamber F; separating a chamber H, wherein the pressure PH in the chamber H is static; separating a chamber G, wherein the static pressure PG in the chamber G; the gap between the balance air seal and the balance disc forms an air flow channel M, an air flow channel N is arranged in the air inlet shell 1, the minimum cross-sectional area of the air flow channel M along the air flow direction is S1, and the minimum cross-sectional area of the air flow channel N along the air flow 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+50KPa.

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 expander is core equipment of the organic Rankine cycle system. Along with the promotion of energy conservation and emission reduction policies, the organic working medium expansion machine is increasingly applied to various industrial enterprises, and through efficient design, the emission can be reduced and the investment recovery period can be shortened. Meanwhile, the load change generated by a factory can cause the flow change of a waste heat source, the pressure of an inlet and an outlet of the rotor of the expander is caused by the operation under the working condition of frequent start and stop, the axial force change is large, and the working condition of the rotor of the expander is bad. The prior design improves isentropic efficiency through a high inverse force design, axial force abnormality is easy to occur, rotor axial force can be reduced through a low inverse force design, efficiency is low, and the running state of the rotor is unstable when inlet and outlet pressure changes are large, and a reliable and efficient rotor of the organic working medium expansion machine can be designed only by accurately grasping the pressure distribution characteristics of each level of the rotor and the through-flow performance of each channel of gas.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide the rotor of the organic working medium expansion machine, which has good pneumatic isentropic efficiency and reasonable axial force, can be well adapted to variable working conditions, and has reasonable structure and convenient assembly.

The purpose of the invention is realized in the following way:

an organic working medium expander rotor comprising:

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

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

a primary nozzle ring, a secondary nozzle ring, a final nozzle ring, and a nozzle ring holder;

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;

the outlet diversion and the final stage gas seal are arranged on the exhaust shell;

the air inlet shell, the nozzle ring seat, the first-stage nozzle ring, the balance air seal and the balance disc separate a cavity A, and static pressure PA in the cavity;

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

the nozzle ring seat, the primary turbine and the secondary nozzle ring separate a cavity C, and static pressure PC in the cavity C;

the nozzle ring seat, the secondary nozzle ring and the secondary turbine separate a chamber D, and static pressure PD in the chamber D;

the nozzle ring seat, the secondary turbine and the final nozzle ring separate a cavity E, and static pressure PE in the cavity E;

the nozzle ring seat, the final nozzle ring and the final turbine separate a chamber F, and static pressure PF in the chamber F;

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

the air inlet shell, the mechanical seal, the main shaft, the balance air seal and the balance disc separate a cavity G, and static pressure PG is arranged in the cavity G;

the gap between the balance air seal and the balance disc forms an air flow channel M, an air flow channel N is arranged in the air inlet shell 1, the minimum cross-sectional area of the air flow channel M along the air flow direction is S1, and the minimum cross-sectional area of the air flow channel N along the air flow direction is S2;

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

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

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;

s1 and S2 are as follows with the chamber pressure change rule: PA/PH > S2/S1 is more than or equal to 1.7, PG < PH+50KPa.

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 increases the reliability of the expander.

Through the scheme, the internal pressure of the turbine stage is stably reduced, so that the flow rates of the turbine and the nozzle ring are relatively balanced in the same turbine stage, the highest flow rate is reduced, the loss can be effectively reduced due to the positive correlation of the loss and the number of times of existence of the flow rate being greater than 1 by reasonable flow rate distribution, and the shock loss caused by shock wave formation can be effectively avoided under the condition of higher expansion ratio, so that the stage efficiency is relatively higher. The differential pressure at two sides of the first-stage turbine is relatively maximum, and by distributing pressure according to 7> (PA-PB)/(PB-PC) >5, the stress at two sides of the wheel disc can be reduced, the total differential pressure of the two rear stages is relatively smaller, and the distribution ratio is properly improved, so that the turbine efficiency is improved. By adjusting the area ratio of S1 and S2, the balance disc can offset a portion of the axial force and reduce the amount of leakage. When the inlet pressure of the expander is increased, the outlet pressure is unchanged, the pressure difference at two sides of each stage of wheel disc is increased, each stage of wheel disc is subjected to force directed to the right, the force directed to the left of the balance disc is correspondingly increased, and the two phases are counteracted, so that the overall axial force of the rotor is promoted to return to a normal range. Through the scheme, pneumatic loss can be effectively reduced, so that isentropic efficiency is improved, and pneumatic axial force balance of the rotor is effectively ensured.

Drawings

FIG. 1 is a schematic diagram of the structure of the present invention;

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

Reference numerals

In the drawing, an air inlet shell 1, a mechanical seal 2, a main shaft 3, balance disc bolts 4, a balance air seal 5, a balance disc 6, a nozzle ring seat 7, a primary nozzle ring 8, a primary turbine 9, a secondary nozzle ring 10, a secondary turbine 11, a final nozzle ring 12, a final turbine 13, a main shaft nut 14, an outlet guide 15, a final air seal 16 and an exhaust shell 17.

Detailed Description

As shown in fig. 1, an axial force stabilizing system of an expander is characterized in that a mechanical seal 2, a balance air seal 5 and a nozzle ring seat 7 are arranged on an air inlet shell 1, balance disc bolts 4, a balance disc 6, a first-stage turbine 9, a secondary turbine 11 and a final-stage turbine 13, a main shaft nut 14 is arranged on a main shaft, the outlet of the main shaft is guided, and a final air seal 16 is arranged on an exhaust shell 17; a primary nozzle ring 8, a secondary nozzle ring 10, and a final nozzle ring 12 are mounted on the nozzle ring holder 7.

Referring to fig. 2 in combination with fig. 1, the air inlet shell 1, the nozzle ring seat 7, the first-stage nozzle ring 8, the balance air seal 5 and the balance disc 6 separate a chamber a, and the static pressure PA in the chamber; the first-stage turbine 9 of the first-stage nozzle ring 8 of the nozzle ring seat 7 separates a cavity B, and the static pressure PB in the cavity; the nozzle ring seat 7, the first turbine 9, the secondary nozzle ring 10 separates the chamber C, the static pressure PC in the chamber; the nozzle ring seat 7, the secondary nozzle ring 10, the secondary turbine 11 separates the chamber D, the chamber internal static pressure PD; a nozzle ring seat 7, a secondary turbine 11, a final nozzle ring 12, separating a chamber E, a chamber internal static pressure PE; the nozzle ring seat 7, the final nozzle ring 12, the final turbine 13 separates a chamber F, a chamber internal static pressure PF, the final turbine 13, a spindle nut 14, an outlet guide 15, a final gas seal 16, the nozzle ring seat 7, an exhaust shell 17 separates a chamber H, and a chamber internal static pressure PH; the air inlet shell 1, the mechanical seal 2, the main shaft 3, the balance air seal 5 and the balance disc 6 are separated from a cavity G, static pressure PG in the cavity, the balance air seal 5 and gaps between the balance disc 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 degree is greater than 0.1, and the gas pressures of the chambers are ranked according to the order: PA > PB > PC > PD > PE > PF > PG-PH to improve the pneumatic isentropic efficiency. The change rule of the pressure difference 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, reducing the pressure at both sides of the primary turbine, controlling the pressure at both sides of the secondary turbine and the final turbine within a reasonable range, and the change rule of S1 and S2 and the chamber pressure is as follows: 1.3H/A > S2/S1> H/A promotes the fluidity of the gas in the chamber G, and ensures PG < PH+50KPa.

Finally, it is noted that the above-mentioned preferred embodiments are only intended to illustrate rather than limit the invention, and that, although the invention has been described in detail by means of the above-mentioned preferred embodiments, it will be understood by those skilled in the art that various changes in form and details 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;

the gap between the balance air seal and the balance disc forms an air flow channel M, an air flow channel N is arranged in the air inlet shell (1), the minimum cross-sectional area of the air flow channel M along the air flow direction is S1, and the minimum cross-sectional area of the air flow channel N along the air flow direction is S2;

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

s1 and S2 are as follows with the chamber pressure change rule: 1.3PH/PA > S2/S1> PH/PA, PG < PH+50KPa.