CN213063680U

CN213063680U - External heating type pump-free self-compression organic Rankine cycle system

Info

Publication number: CN213063680U
Application number: CN202021406892.2U
Authority: CN
Inventors: 雷标; 吴玉庭; 王伟; 马重芳
Original assignee: Beijing University of Technology
Current assignee: Beijing University of Technology
Priority date: 2020-07-16
Filing date: 2020-07-16
Publication date: 2021-04-27
Anticipated expiration: 2030-07-16

Abstract

An external heating type pump-free self-compression organic Rankine cycle system belongs to the field of medium-low grade energy utilization. The cylinder with non-equal diameter is provided with a main piston and an auxiliary piston. The main piston and the auxiliary piston both reciprocate between the respective top dead center and the respective bottom dead center, the auxiliary piston is in a non-equal-diameter T-shaped structure, the small diameter of the auxiliary piston is matched with the small diameter of the cylinder, and the main piston changes the reciprocating motion into the rotary motion through connection. The small-diameter space at the bottom of the cylinder is a suction chamber and is respectively connected with an evaporator inlet and a condenser outlet through a one-way valve plate; the working volume is arranged between the main piston and the auxiliary piston, and the working volume is respectively connected with the inlet of the condenser and the outlet of the evaporator through valves. An auxiliary piston gap is arranged between the auxiliary piston groove and the cylinder, a spring is arranged in the auxiliary piston gap, and the auxiliary piston gap is connected with an inlet of the condenser through a pipeline. The system is filled with organic working medium. The working medium is compressed, absorbs heat and expands to do work in the cylinder through the movement of the main piston and the auxiliary piston, and exhaust gas enters the condenser to be condensed and is recycled.

Description

External heating type pump-free self-compression organic Rankine cycle system

Technical Field

The utility model relates to an external heating type pump-free self-compression organic Rankine cycle system, which belongs to the field of medium-low grade energy utilization.

Background

The organic rankine cycle system has significant advantages in recycling various middle and low grade heat energy such as industrial waste heat and solar energy, and the existing research mainly uses the energy generated by the system for power generation. In an organic Rankine cycle system, an expander is a power output part, a working medium pump consumes a part of shaft work of the expander, and as the critical temperature of an organic working medium is far lower than that of water, the theoretical pump work of the organic Rankine cycle is much larger than that of a traditional steam power cycle. Because the pressure of the working medium pump is very high, the efficiency of the working medium pump is too low, and particularly in small-scale organic Rankine cycle, the working medium pump has very large irreversible loss and very large power consumption, and the performance improvement of the organic Rankine cycle is influenced. The pump-free organic Rankine cycle system in the current literature either utilizes a large height difference to provide cycle power or cannot continuously work.

SUMMERY OF THE UTILITY MODEL

The utility model aims at overcoming the not enough of prior art and providing an external heating formula does not have pump self-compression organic rankine cycle system.

As shown in fig. 1, the specific structure is: the non-equal-diameter cylindrical cylinder (1) is internally provided with a main piston (2) and an auxiliary piston (3), the upper part of the non-equal-diameter cylindrical cylinder (1) is a large-diameter space part, and the lower part of the non-equal-diameter cylindrical cylinder (1) is a small-diameter space part; the main piston (2) is positioned in a large-diameter space at the upper part of the non-equal-diameter cylindrical cylinder (1), and the main piston (2) reciprocates between a first top dead center (2a) and a first bottom dead center (2 b); the auxiliary piston (3) is of a non-equal-diameter T-shaped structure, the upper part is a large-diameter part, the lower part is a small-diameter part, the small-diameter part of the auxiliary piston (3) is matched with the small-diameter space part at the bottom of the non-equal-diameter cylindrical cylinder (1), the large-diameter part of the auxiliary piston (3) is matched with the large-diameter space part of the non-equal-diameter cylindrical cylinder (1), and the auxiliary piston (3) reciprocates between a second top dead center (3a) and a second bottom dead center (3 b); the main piston (2) can be connected with a connecting rod, a crankshaft and the like through connection, and converts reciprocating motion into rotary motion to realize mechanical energy output; the small-diameter space part at the bottom of the non-isodiametric cylindrical cylinder (1) is divided into a suction chamber (A), the corresponding cylinder volume between the main piston (2) and the auxiliary piston (3) is a working volume (B), namely the working volume (B) between a first top dead center (2a) and a second top dead center (3a), and the compression, heating and expansion of a working medium are realized; the working volume (B) between the first top dead center (2a) and the second top dead center (3a) is respectively connected with the inlet of a condenser (9) through a first valve (5) and the outlet of an evaporator (10) through a second valve (6); an annular gap formed between the small diameter of the auxiliary piston (3) and the cylinder (1) is an auxiliary piston gap (C), a spring (4) is installed in the auxiliary piston gap, and the auxiliary piston gap (C) is connected with an inlet of a condenser (9) through a pipeline (11); the suction chamber (A) is respectively connected with an inlet of an evaporator (10) through a first one-way valve plate (7) and an outlet of a condenser (9) through a second one-way valve plate (8); the outlet of the evaporator (10) is connected with the inlet of the condenser (9) through an expander (12); the system is filled with organic matters as working media.

The working principle of the external heating type pump-free self-compression organic Rankine cycle system is characterized by comprising the following steps:

under the normal working state, when the main piston (2) runs to a first top dead center (2a), the auxiliary piston (3) is also positioned at a second top dead center (3a), at the moment, the working volume (B) is minimum, the suction chamber (A) is maximum, the suction chamber (A) is filled with organic working medium liquid, the first valve (5) is closed, the second valve (6) is opened, a part of high-pressure steam from the evaporator (10) enters the working volume (B), and the rest part of high-pressure steam enters the expansion machine (12); after the working volume (B) is filled with high-pressure steam, the working volume (B) is in a high-pressure state, the high-pressure gas forces the main piston (2) to move towards a first bottom dead center (2B) on one hand and outputs mechanical work, and forces the auxiliary piston (3) to compress the spring (4) and move towards a second bottom dead center (3B) on the other hand; because the auxiliary piston gap (C) is communicated with the inlet of the condenser (9) through the pipeline (11) and is always in a low-pressure state, the pressure in the suction chamber (A) is higher than the pressure in the working volume (B) and the inlet of the evaporator (10) due to the movement of the auxiliary piston (3), the first one-way valve plate (7) is opened, and organic working medium liquid in the suction chamber (A) enters the evaporator (10); when the main piston (2) moves to a certain middle position towards the first bottom dead center (2B), the auxiliary piston (3) moves to the second bottom dead center (3B), all liquid in the suction chamber (A) is sent to the evaporator, the one-way valve plate (7) is closed, then the second valve (6) is closed, the main piston (2) continues to move towards the first bottom dead center (2B), and in the moving process, due to the increase of the volume of the working volume (B), the pressure of a working medium in the main piston decreases; when the main piston (2) moves to a first bottom dead center (2B), the pressure in the working volume (B) is reduced to be close to the condensing pressure, at the moment, the first valve (5) is opened, the main piston (2) starts to move from the first bottom dead center (2B) to a first top dead center (2a), exhaust gas which is expanded in the working volume (B) and is exhausted out of the non-equal-diameter cylindrical cylinder (1) is sent to a condenser (9) for condensing, the pressure in the working volume (B) is lower and is about the condensing pressure, the auxiliary piston (3) gradually moves to a second top dead center (3a) under the action of the spring (4), the pressure in the suction chamber (A) is reduced, the second one-way valve plate (8) is opened, and condensate which comes out of the condenser (9) enters the suction chamber (A); when the auxiliary piston (3) moves to a second top dead center (3a), the suction chamber (A) is filled with organic working medium liquid, and the second one-way valve plate (8) is closed; when the main piston (2) moves to the first top dead center (2a), the first valve (5) is closed, the second valve (6) is opened, and high-pressure steam from the evaporator (10) enters the working volume (B) to start the next cycle.

In the utility model, the opening and closing of the first valve (5) and the second valve (6) are generally controlled by a control system, and the opening and closing of the first valve and the second valve depend on the angle of a crankshaft or the position and the moving direction of a piston; the control mode can be mechanical control, for example, the cam mechanism pushes the cam mechanism open at a certain rotation phase; or electronic control, for example, a sensor is used for detecting the position of the piston or the angle of a crankshaft, and a control signal is sent out to realize the opening and closing of the first valve (5) and the second valve (6).

Optionally, the utility model discloses also can not set up expander (12), whole high-pressure steam that evaporimeter (10) came out promptly gets into working volume (B), and the expansion work is done work and is compressed, carried organic working medium liquid.

Drawings

FIG. 1 shows an externally-heated pump-free self-compression organic Rankine cycle system

The air cylinder comprises a cylinder (1), a main piston (2), an auxiliary piston (3), a spring (4), a first valve (5), a second valve (6), a first check valve plate (7), a second check valve plate (8), a condenser (9), an evaporator (10), a pipeline (11), an expander (12), a first top dead center (2a), a first bottom dead center (2B), a second top dead center (3a), a second bottom dead center (3B), a suction chamber (A), a working volume (B) and an auxiliary piston gap (C).

Detailed Description

The present invention will be further described with reference to the following examples, but the present invention is not limited to the following examples.

Example 1:

in a cylinder (1) of a cylinder type having a non-equal diameter as shown in fig. 1, a main piston (2) and an auxiliary piston (3) are mounted. The main piston (2) reciprocates between a first top dead center (2a) and a first bottom dead center (2b), the auxiliary piston (3) is of a non-equal-diameter T-shaped structure, the small diameter part of the auxiliary piston is matched with the small diameter part of the bottom of the cylinder, and the auxiliary piston reciprocates between a second top dead center (3a) and a second bottom dead center (3 b). The main piston (2) can be connected with a connecting rod, a crankshaft and the like to convert reciprocating motion into rotary motion, thereby realizing mechanical energy output. The small-diameter space at the bottom of the cylinder is a suction chamber (A), and the cylinder volume between the main piston (2) and the auxiliary piston (3) is a working volume (B), so that working medium compression, heating and expansion are realized. The working volume (B) between the first top dead center (2a) and the second top dead center (3a) is respectively connected with the inlet of the condenser (9) and the outlet of the evaporator (10) through the first valve (5) and the second valve (6). An auxiliary piston gap (C) is arranged between the groove of the auxiliary piston (3) and the cylinder (1), a spring (4) is arranged in the auxiliary piston gap, and the auxiliary piston gap is introduced into an inlet of the condenser (9) through a pipeline (11). The suction chamber (A) is connected with an inlet of an evaporator (10) and an outlet of a condenser (9) through a first check valve plate (7) and a second check valve plate (8). An expander (12) is installed between the evaporator (10) and the condenser (8). The system is filled with organic matters as working media.

Under the normal working state, when the main piston (2) runs to a first top dead center (2a), the auxiliary piston (3) is also positioned at a second top dead center (3a), at the moment, the working volume (B) is minimum, the suction chamber (A) is maximum, and the suction chamber (A) is filled with organic working medium liquid. The first valve (5) is closed and the second valve (6) is opened, and a portion of the high pressure steam from the evaporator (10) enters the working volume (B) and the remainder enters the expander (12). After the working volume (B) is filled with high pressure steam, it is in a high pressure state. On one hand, the high-pressure gas forces the main piston (2) to move towards a first bottom dead center (2b) and outputs mechanical work; on the one hand, the auxiliary piston (3) is forced to compress the spring (4) and move towards the second bottom dead center (3 b). Because the auxiliary piston gap (C) is communicated with the inlet of the condenser (9) through the pipeline (11) and is always in a low-pressure state, the pressure in the suction chamber (A) is higher than the pressure in the working volume (B) and the inlet of the evaporator (10) due to the movement of the auxiliary piston (3), the first one-way valve plate (7) is opened, and organic working medium liquid in the suction chamber (A) enters the evaporator (10). When the main piston (2) moves to a certain middle position towards the first bottom dead center (2b), the auxiliary piston (3) moves to the second bottom dead center (3b), all liquid in the suction chamber (A) is sent to the evaporator, and the first check valve plate (7) is closed. Then the second valve (6) is closed, the main piston (2) continues to move towards the first bottom dead center (2B), and in the moving process, due to the fact that the volume of the working volume (B) is increased, the pressure of the working medium in the main piston is reduced. When the main piston (2) moves to a first bottom dead center (2B), the pressure in the working volume (B) is reduced to be close to the condensing pressure, at the moment, the first valve (5) is opened, the main piston (2) starts to move from the first bottom dead center (2B) to a first top dead center (2a), and exhaust gas after expansion in the working volume is discharged out of the cylinder (1) and is sent to a condenser (9) for condensing. During the period, the pressure in the working volume (B) is lower and is about the condensing pressure, the auxiliary piston (3) gradually moves to a second top dead center (3a) under the action of the spring (4), the pressure in the suction chamber (A) is reduced, the second one-way valve plate (8) is opened, and the condensate coming out of the condenser (9) enters the suction chamber (A). When the auxiliary piston (3) moves to a second top dead center (3a), the suction chamber (A) is filled with organic working medium liquid, and the one-way valve plate (8) is closed. When the main piston (2) moves to the first top dead center (2a), the first valve (5) is closed, the second valve (6) is opened, and high-pressure steam from the evaporator (10) enters the working volume (B) to start the next cycle.

The utility model discloses in, first valve (5), second valve (6) are opened and close and are generally controlled by special control system, and its switching depends on bent axle angle or piston position, direction of motion. The control mode can be mechanical control, for example, the cam mechanism pushes the cam mechanism open at a certain rotation phase; or electronic control, for example, a sensor is used for detecting the position of the piston or the angle of a crankshaft, and a control signal is sent out to realize the opening and closing of the first valve (5) and the second valve (6).

Claims

1. An external heating type pump-free self-compression organic Rankine cycle system is characterized in that a main piston (2) and an auxiliary piston (3) are installed in a non-equal-diameter cylindrical cylinder (1), the upper part of the non-equal-diameter cylindrical cylinder (1) is a large-diameter space part, and the lower part of the non-equal-diameter cylindrical cylinder (1) is a small-diameter space part; the main piston (2) is positioned in a large-diameter space at the upper part of the non-equal-diameter cylindrical cylinder (1), and the main piston (2) reciprocates between a first top dead center (2a) and a first bottom dead center (2 b); the auxiliary piston (3) is of a non-equal-diameter T-shaped structure, the upper part is a large-diameter part, the lower part is a small-diameter part, the small-diameter part of the auxiliary piston (3) is matched with the small-diameter space part at the bottom of the non-equal-diameter cylindrical cylinder (1), the large-diameter part of the auxiliary piston (3) is matched with the large-diameter space part of the non-equal-diameter cylindrical cylinder (1), and the auxiliary piston (3) reciprocates between a second top dead center (3a) and a second bottom dead center (3 b); the main piston (2) can be connected with a connecting rod, a crankshaft and the like through connection, and converts reciprocating motion into rotary motion to realize mechanical energy output; the small-diameter space part at the bottom of the non-isodiametric cylindrical cylinder (1) is divided into a suction chamber (A), the corresponding cylinder volume between the main piston (2) and the auxiliary piston (3) is a working volume (B), namely the working volume (B) between a first top dead center (2a) and a second top dead center (3a), and the compression, heating and expansion of a working medium are realized; the working volume (B) between the first top dead center (2a) and the second top dead center (3a) is respectively connected with the inlet of a condenser (9) through a first valve (5) and the outlet of an evaporator (10) through a second valve (6); an annular gap formed between the small diameter of the auxiliary piston (3) and the cylinder (1) is an auxiliary piston gap (C), a spring (4) is installed in the auxiliary piston gap, and the auxiliary piston gap (C) is connected with an inlet of a condenser (9) through a pipeline (11); the suction chamber (A) is respectively connected with an inlet of an evaporator (10) through a first one-way valve plate (7) and an outlet of a condenser (9) through a second one-way valve plate (8); the outlet of the evaporator (10) is connected with the inlet of the condenser (9) through an expander (12); the system is filled with organic matters as working media.

2. An external heating type pump-free self-compression organic Rankine cycle system according to claim 1, wherein the opening and closing of the first valve (5) and the second valve (6) are controlled by a control system, and the opening and closing of the valves depend on the crank angle or the piston position and the moving direction; the control mode can be mechanical control or electronic control.

3. An external heating type pump-free self-compression organic Rankine cycle system according to claim 1, wherein under normal operation, when the main piston (2) moves to the first top dead center (2a), the auxiliary piston (3) is also located at the second top dead center (3a), at which the working volume (B) is minimum, the suction chamber (A) is maximum, and the suction chamber (A) is filled with organic working medium liquid, the first valve (5) is closed, the second valve (6) is opened, a part of high-pressure steam from the evaporator (10) enters the working volume (B), and the rest enters the expander (12); after the working volume (B) is filled with high-pressure steam, the working volume (B) is in a high-pressure state, the high-pressure gas forces the main piston (2) to move towards a first bottom dead center (2B) on one hand and outputs mechanical work, and forces the auxiliary piston (3) to compress the spring (4) and move towards a second bottom dead center (3B) on the other hand; because the auxiliary piston gap (C) is communicated with the inlet of the condenser (9) through the pipeline (11) and is always in a low-pressure state, the pressure in the suction chamber (A) is higher than the pressure in the working volume (B) and the inlet of the evaporator (10) due to the movement of the auxiliary piston (3), the first one-way valve plate (7) is opened, and organic working medium liquid in the suction chamber (A) enters the evaporator (10); when the main piston (2) moves to a certain middle position towards the first bottom dead center (2B), the auxiliary piston (3) moves to the second bottom dead center (3B), all liquid in the suction chamber (A) is sent to the evaporator, the one-way valve plate (7) is closed, then the second valve (6) is closed, the main piston (2) continues to move towards the first bottom dead center (2B), and in the moving process, due to the increase of the volume of the working volume (B), the pressure of a working medium in the main piston decreases; when the main piston (2) moves to a first bottom dead center (2B), the pressure in the working volume (B) is reduced to be close to the condensing pressure, at the moment, the first valve (5) is opened, the main piston (2) starts to move from the first bottom dead center (2B) to a first top dead center (2a), exhaust gas which is expanded in the working volume (B) and is exhausted out of the non-equal-diameter cylindrical cylinder (1) is sent to a condenser (9) for condensing, the pressure in the working volume (B) is lower and is about the condensing pressure, the auxiliary piston (3) gradually moves to a second top dead center (3a) under the action of the spring (4), the pressure in the suction chamber (A) is reduced, the second one-way valve plate (8) is opened, and condensate which comes out of the condenser (9) enters the suction chamber (A); when the auxiliary piston (3) moves to a second top dead center (3a), the suction chamber (A) is filled with organic working medium liquid, and the second one-way valve plate (8) is closed; when the main piston (2) moves to the first top dead center (2a), the first valve (5) is closed, the second valve (6) is opened, and high-pressure steam from the evaporator (10) enters the working volume (B) to start the next cycle.

4. An external heating type pump-free self-compression organic Rankine cycle system according to any one of claims 1 to 3, wherein the expander (12) is not provided, that is, all high-pressure steam from the evaporator (10) enters the working volume (B) and is expanded to work, compress and convey organic working medium liquid.