CN116428013A - Piston type expansion unit and two-stage expansion system - Google Patents

Piston type expansion unit and two-stage expansion system Download PDF

Info

Publication number
CN116428013A
CN116428013A CN202310417595.XA CN202310417595A CN116428013A CN 116428013 A CN116428013 A CN 116428013A CN 202310417595 A CN202310417595 A CN 202310417595A CN 116428013 A CN116428013 A CN 116428013A
Authority
CN
China
Prior art keywords
stage
electromagnetic valve
valve
level
control unit
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202310417595.XA
Other languages
Chinese (zh)
Inventor
虞启辉
张家宝
孙国鑫
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Inner Mongolia University of Science and Technology
Original Assignee
Inner Mongolia University of Science and Technology
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Inner Mongolia University of Science and Technology filed Critical Inner Mongolia University of Science and Technology
Priority to CN202310417595.XA priority Critical patent/CN116428013A/en
Publication of CN116428013A publication Critical patent/CN116428013A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01B—MACHINES OR ENGINES, IN GENERAL OR OF POSITIVE-DISPLACEMENT TYPE, e.g. STEAM ENGINES
    • F01B25/00—Regulating, controlling, or safety means
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01B—MACHINES OR ENGINES, IN GENERAL OR OF POSITIVE-DISPLACEMENT TYPE, e.g. STEAM ENGINES
    • F01B1/00—Reciprocating-piston machines or engines characterised by number or relative disposition of cylinders or by being built-up from separate cylinder-crankcase elements
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01B—MACHINES OR ENGINES, IN GENERAL OR OF POSITIVE-DISPLACEMENT TYPE, e.g. STEAM ENGINES
    • F01B25/00—Regulating, controlling, or safety means
    • F01B25/02—Regulating or controlling by varying working-fluid admission or exhaust, e.g. by varying pressure or quantity
    • F01B25/08—Final actuators
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01B—MACHINES OR ENGINES, IN GENERAL OR OF POSITIVE-DISPLACEMENT TYPE, e.g. STEAM ENGINES
    • F01B25/00—Regulating, controlling, or safety means
    • F01B25/02—Regulating or controlling by varying working-fluid admission or exhaust, e.g. by varying pressure or quantity
    • F01B25/08—Final actuators
    • F01B25/10—Arrangements or adaptations of working-fluid admission or discharge valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01B—MACHINES OR ENGINES, IN GENERAL OR OF POSITIVE-DISPLACEMENT TYPE, e.g. STEAM ENGINES
    • F01B31/00—Component parts, details, or accessories not provided for in, or of interest apart from, other groups

Abstract

The application discloses a piston type expansion unit and a two-stage expansion system, which comprise a piston type expansion unit, wherein an exhaust valve of a first-stage cylinder is connected with an intake valve of a second-stage cylinder through a pipeline, and the pipeline is connected with a second-stage constant pressure gas storage device; the controller is also connected with a II-level air inlet control unit and a II-level air outlet control unit, the II-level air inlet control unit and the II-level air outlet control unit are connected with the II-level air cylinder, and the II-level air inlet control unit and the II-level air outlet control unit are respectively used for inflating and deflating the II-level air cylinder; the second-level air inlet control unit and the second-level air outlet control unit are connected with the second-level constant-pressure air storage device or the first-level constant-pressure air storage device; the problem that the driving mechanism of the air inlet valve and the air outlet valve in the prior art is additionally provided with starting power is solved; meanwhile, the problems of compressed air resource waste and incomplete expansion and large loss of the single-stage piston 4 type expander and the traditional two-stage piston 4 type expander are solved.

Description

Piston type expansion unit and two-stage expansion system
Technical Field
The invention relates to the technical field of air energy storage, in particular to a piston type expansion unit and a two-stage expansion system.
Background
An air energy storage system is taken as one of energy storage technologies, and has the characteristics of low cost, long service life and zero emission, so that the air energy storage system is paid attention to all over the world; the system comprises an air energy storage system, an expander, a control system and a control system, wherein the expander is used as a terminal power output link of the air energy storage system, and the efficiency and the operation characteristics of the expander have decisive influence on the overall operation performance of the air energy storage system; research shows that the piston type expander is more suitable for a small-sized air energy storage system.
At present, in the actual use process, a single-stage piston type expansion machine is generally used, and specifically referring to fig. 1, a schematic three-dimensional structure diagram of the single-stage piston type expansion machine is shown, and as can be seen from the figure, the single-stage piston type expansion machine comprises a stage i cylinder, an air inlet valve and an air outlet valve are connected above the stage i cylinder, a piston is arranged in the stage i cylinder, a connecting rod is connected below the piston, and the other end of the connecting rod is connected with an output shaft; working principle of single-stage piston type expander: when air is taken in, an air inlet valve is opened (an exhaust valve is closed), working medium (air gas) enters a cavity of the first-stage air cylinder, and the working medium (air gas) pushes the piston to move downwards; after the air intake is completed, the air inlet valve is closed, and at the moment, working medium (air gas) continues to expand and do work to continuously push the piston to move. When exhausting, the exhaust valve is opened (the intake valve is closed), working medium (air gas) is exhausted from the exhaust valve, and then the piston is driven to move upwards.
However, the single stage piston expander disclosed above has problems in that: in the prior art, a driving mechanism for moving an air inlet valve and an air outlet valve needs to be separately provided with starting power, and if the driving mechanism is a cam valve mechanism, the starting power is provided for the driving mechanism, namely the power output by a motor.
Disclosure of Invention
Therefore, the present invention is directed to a piston expansion unit and a two-stage expansion system, which solve the problem that in the prior art, the driving mechanism of the intake valve and the exhaust valve needs to be additionally provided with starting power.
The invention discloses a piston type expansion unit, which comprises a first-stage cylinder, wherein an intake valve and an exhaust valve are arranged on the first-stage cylinder, a variable valve distribution control module is arranged on the first-stage cylinder, and the variable valve distribution control module controls the opening or closing of the intake valve and the exhaust valve; one side of the I-stage cylinder is provided with a I-stage constant-pressure gas storage device which is respectively connected with the air inlet valve and the variable valve air distribution control module.
As a further definition of the cylinder: a piston is arranged in the I-stage cylinder, one end of the piston is connected with a connecting rod, the other end of the connecting rod is connected with a crankshaft, and the crankshaft is used for being connected with an output device.
As a further definition of a variable valve distribution control module: the variable valve gas distribution control module comprises a controller, wherein the controller is connected with a level I gas inlet control unit and a level I gas outlet control unit, and the level I gas inlet control unit and the level I gas outlet control unit are connected with a level I constant pressure gas storage device; the I-stage air inlet control unit and the I-stage air outlet control unit are respectively used for inflating and deflating the I-stage air cylinder.
As a further definition of the stage i intake control unit, the stage i exhaust control unit: the I-stage air inlet control unit or the I-stage air outlet control unit comprises a valve actuator; the valve actuator comprises a cylinder cavity, wherein a partition plate is arranged in the cylinder cavity and is used for dividing the cylinder cavity into an upper cavity and a lower cavity; the upper part and the lower part of the baffle are respectively provided with a double-layer piston connecting rod in a sealing and sliding manner, the double-layer piston connecting rods pass through the cylinder cavity in a sliding manner and are connected with an air inlet valve, the air inlet valve movably passes through the I-stage cylinder, and the air inlet valve is used for blocking or opening the air inlet valve.
As a first optimization scheme for the present invention: the air inlet valve is provided with a pressing sheet, and a pre-tightening spring is arranged at the joint of the pressing sheet and the air cylinder.
As a further definition of the stage i intake control unit, the stage i exhaust control unit: the I-stage air inlet control unit or the I-stage air outlet control unit also comprises an electromagnetic valve; the electromagnetic valves comprise a first electromagnetic valve, a second electromagnetic valve, a third electromagnetic valve, a fourth electromagnetic valve, a fifth electromagnetic valve, a sixth electromagnetic valve, a seventh electromagnetic valve and an eighth electromagnetic valve; the first electromagnetic valve, the second electromagnetic valve, the third electromagnetic valve, the fourth electromagnetic valve, the fifth electromagnetic valve, the sixth electromagnetic valve, the seventh electromagnetic valve and the eighth electromagnetic valve are connected with the controller and the cylinder cavity; the first electromagnetic valve and the second electromagnetic valve are communicated with a cavity above the upper baffle part of the double-layer piston connecting rod, the third electromagnetic valve and the fourth electromagnetic valve are communicated with a cavity between the upper baffle part of the double-layer piston connecting rod and the partition plate, the fifth electromagnetic valve and the sixth electromagnetic valve are communicated with a cavity between the lower baffle part of the double-layer piston connecting rod, and the seventh electromagnetic valve and the eighth electromagnetic valve are communicated with a cavity below the lower baffle part of the double-layer piston connecting rod; the I-stage constant-pressure gas storage device is connected with a first electromagnetic valve, a second electromagnetic valve, a third electromagnetic valve, a fourth electromagnetic valve, a fifth electromagnetic valve, a sixth electromagnetic valve, a seventh electromagnetic valve and an eighth electromagnetic valve.
As a second optimization scheme for the present invention: the air outlet end of the I-level constant-pressure air storage device is provided with a I-level one-way valve, and the outflow direction of working medium in the I-level constant-pressure air storage device is consistent with that of working medium in the I-level constant-pressure air storage device.
In a second aspect, the invention discloses a two-stage expansion system, which comprises a piston expansion unit and a grade II cylinder, wherein an exhaust valve of the grade I cylinder is connected with an intake valve of the grade II cylinder through a pipeline, and the pipeline is connected with a grade II constant pressure gas storage device; the controller is also connected with a II-level air inlet control unit and a II-level air outlet control unit, the II-level air inlet control unit and the II-level air outlet control unit are connected with the II-level air cylinder, and the II-level air inlet control unit and the II-level air outlet control unit are respectively used for inflating and deflating the II-level air cylinder; the II-stage air inlet control unit and the II-stage air outlet control unit are connected with the II-stage constant-pressure air storage device or the I-stage constant-pressure air storage device.
As a further definition of a dual stage expansion system: the I-level constant-pressure gas storage device or the II-level constant-pressure gas storage device comprises a storage tank, one side of the storage tank is provided with a bidirectional quantitative hydraulic pump and a water tank, and the storage tank is connected with the bidirectional quantitative hydraulic pump and the water tank in series.
As a third optimization scheme for the present invention: the pipeline is connected with a second-level one-way valve, and the flow direction of the second-level one-way valve is consistent with that of the first-level one-way valve.
The beneficial effects of the invention are as follows:
firstly, the invention can divide the air in the I-level constant-pressure air storage device into two parts and respectively distribute the air to the I-level air cylinder, the I-level air inlet control unit or the I-level air outlet control unit.
Secondly, the invention realizes flexible control of the air inlet valve and the air outlet valve by adopting an electric pneumatic variable valve structure, ensures the constancy of the gas pressure in the pipeline by arranging the constant-pressure gas storage device between the communicating pipelines of the first-stage cylinder and the second-stage cylinder, solves the problems of compressed air resource waste and incomplete expansion and great loss of the single-stage piston type expander and the traditional two-stage piston type expander, and improves the output power and the energy utilization efficiency of the piston type expander.
Drawings
Fig. 1 is a schematic perspective view of a single stage piston expander.
Fig. 2 is a schematic perspective view of a piston type expansion unit.
Fig. 3 is a schematic diagram showing a state of an air intake process of the piston type expansion unit.
Fig. 4 is a schematic diagram showing a state of an expansion process of the piston type expansion unit.
Fig. 5 is a schematic diagram showing a state of the exhaust process of the piston expansion unit.
FIG. 6 is a schematic perspective view of a class I constant pressure gas storage device.
FIG. 7 is a schematic diagram of the overall structure of a dual stage expansion system.
In the figure, a first-stage cylinder 1, an intake valve 2, an exhaust valve 3, a piston 4, a connecting rod 5, a crankshaft 6, a controller 7, a valve actuator 8, a cylinder cavity 801, a partition plate 802, a double-layer piston connecting rod 9, a coupler 10, an intake valve 11, a pressing sheet 12, a pretension spring 13, a blocking body 14, a first electromagnetic valve 15, a second electromagnetic valve 16, a third electromagnetic valve 17, a fourth electromagnetic valve 18, a fifth electromagnetic valve 19, a sixth electromagnetic valve 20, a seventh electromagnetic valve 21, an eighth electromagnetic valve 22, a first-stage check valve 23, a storage tank 24, a bidirectional quantitative hydraulic pump 25, a water tank 26, a second-stage cylinder 27 and a second-stage check valve 28.
Description of the embodiments
For a clear understanding of the technical solutions of the present application, a piston expansion unit and a dual-stage expansion system provided in the present application will be described in detail below with reference to specific embodiments and accompanying drawings.
The terminology used in the following embodiments is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in the specification of this application and the appended claims, the singular forms "a," "an," "the," and "the" are intended to include, for example, "one or more" such forms of expression, unless the context clearly indicates to the contrary. It should also be understood that in the various embodiments herein below, "at least one", "one or more" means one, two or more than two.
Reference in the specification to "one embodiment" or "some embodiments" or the like means that a particular feature, structure, or characteristic described in connection with the embodiment is included in one or more embodiments of the application. Thus, appearances of the phrases "in one embodiment," "in some embodiments," "in other embodiments," and the like in various places throughout this specification are not necessarily all referring to the same embodiment, but mean "one or more, but not all, embodiments" unless expressly specified otherwise. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless expressly specified otherwise.
Examples
The embodiment provides a piston type expansion unit, referring to fig. 2, a schematic diagram of a three-dimensional structure of the piston type expansion unit is shown, and as can be seen from the figure, the piston type expansion unit comprises a first-stage cylinder 1, an intake valve 2 and an exhaust valve 3 are respectively formed on the left side and the right side of the top of the first-stage cylinder 1, a variable valve air distribution control module is mounted on the first-stage cylinder 1, and air intake and exhaust of the intake valve 2 and the exhaust valve 3 are controlled by the variable valve air distribution control module; one side of the I-stage air cylinder 1 is provided with an I-stage constant-pressure air storage device, an air outlet end of the I-stage constant-pressure air storage device is respectively communicated with the air inlet valve 2 and the variable valve air distribution control module, and air generated in the I-stage constant-pressure air storage device is used for inflating the I-stage air cylinder 1 and providing starting power for the variable valve air distribution control module; a piston 4 is arranged in the first-stage cylinder 1, one end of a connecting rod 5 is connected with the piston 4, the other end of the connecting rod 5 is connected with a crankshaft 6, and the other end of the crankshaft 6 is connected with an output device.
With continued reference to fig. 2, as shown in the figure, the variable valve gas distribution control module includes a controller 7, where the controller 7 is connected with a level i gas inlet control unit and a level i gas outlet control unit, respectively, and both the level i gas inlet control unit and the level i gas outlet control unit are connected with a level i constant pressure gas storage device; the I-level air inlet control unit and the I-level air outlet control unit have the same structure, and the specific structure is as follows by taking the I-level air inlet control unit as an example.
The I-stage air inlet control unit comprises a valve actuator 8, the valve actuator 8 is a force doubling cylinder, the valve actuator 8 further comprises a cylinder cavity 801, a baffle 802 is connected to the middle position in the cylinder cavity 801, and the baffle 802 divides the cylinder cavity 801 into an upper cavity and a lower cavity; the baffle 802 is sealed and connected with a double-layer piston connecting rod 9 in a sliding manner, the whole shape of the double-layer piston connecting rod 9 is in a shape of 'earth', an upper baffle part of the double-layer piston connecting rod 9 is arranged above the baffle 802, a lower baffle part of the double-layer piston connecting rod 9 is arranged below the baffle 802, and a protruding part of the double-layer piston connecting rod 9 is sealed and slides to pass through the bottom of the cylinder cavity 801; the convex part of the double-layer piston connecting rod 9 is fixedly connected with the air inlet valve 11 through the coupler 10; the air inlet valve 11 movably penetrates through the top mounting hole of the first-stage air cylinder 1, the pressing sheet 12 is welded on the air inlet valve 11, a pre-tightening spring 13 is arranged between the pressing sheet 12 and the first-stage air cylinder 1, two ends of the pre-tightening spring 13 respectively collide with the pressing sheet 12 and the top of the first-stage air cylinder 1, and the pre-tightening spring 13 can prevent the coupling 10 from colliding with the air inlet valve 2; the air inlet valve 11 is provided with a blocking body 14, and the edge of the mounting hole limits the blocking body 14 of the air inlet valve 11;
two sub-cavities are formed above the cavity of the first-stage cylinder 1 and are communicated with the corresponding intake valve 2 and the exhaust valve 3 respectively; the bottom of the air inlet valve 11 is provided with a convex part, and the convex part of the air inlet valve 11 is abutted against the bottom edge (top dead center) of the corresponding sub-cavity;
the cylinder cavity 801 is sequentially connected with a first electromagnetic valve 15, a second electromagnetic valve 16, a third electromagnetic valve 17, a fourth electromagnetic valve 18, a fifth electromagnetic valve 19, a sixth electromagnetic valve 20, a seventh electromagnetic valve 21 and an eighth electromagnetic valve 22, wherein the first electromagnetic valve 15, the second electromagnetic valve 16, the third electromagnetic valve 17, the fourth electromagnetic valve 18, the fifth electromagnetic valve 19, the sixth electromagnetic valve 20, the seventh electromagnetic valve 21 and the eighth electromagnetic valve 22 are connected with the controller 7, the first electromagnetic valve 15 and the second electromagnetic valve 16 are communicated with a cavity (a cavity) above the upper baffle part of the double-layer piston connecting rod 9, the third electromagnetic valve 17 and the fourth electromagnetic valve 18 are communicated with a cavity (b cavity) between the upper baffle plate 802 and the upper baffle part of the double-layer piston connecting rod 9, the fifth electromagnetic valve 19 and the sixth electromagnetic valve 20 are communicated with a cavity (c cavity) between the lower baffle plate 802, and the seventh electromagnetic valve 21 and the eighth electromagnetic valve 22 are communicated with a cavity (d cavity) below the lower baffle part of the double-layer piston connecting rod 9; the air outlet end of the I-stage constant-pressure air storage device is communicated with a first electromagnetic valve 15, a second electromagnetic valve 16, a third electromagnetic valve 17, a fourth electromagnetic valve 18, a fifth electromagnetic valve 19, a sixth electromagnetic valve 20, a seventh electromagnetic valve 21 and an eighth electromagnetic valve 22.
Note that: the structure of the first-stage exhaust control unit and the first-stage intake control unit is identical, and is not repeated here.
Further, a grade I one-way valve 23 is arranged at the air outlet end of the grade I constant-pressure air storage device, and the outflow direction of working medium in the grade I one-way valve 23 and the grade I constant-pressure air storage device is kept consistent.
Working principle of single-stage piston expansion unit:
in the first step, referring to fig. 3, a schematic state diagram of an air intake process of the piston expansion unit is shown, it can be seen that the first electromagnetic valve 15, the third electromagnetic valve 17, the fifth electromagnetic valve 19 and the seventh electromagnetic valve 21 on the level i air intake control unit are opened by the controller 7, the second electromagnetic valve 16, the fourth electromagnetic valve 18, the sixth electromagnetic valve 20 and the eighth electromagnetic valve 22 on the level i air intake control unit are closed, a part of air in the level i constant pressure air storage device sequentially passes through the level i check valve 23, the first electromagnetic valve 15 and the fifth electromagnetic valve 19 (along the direction b 1) to enter the corresponding a cavity and b cavity in the valve actuator 8, and air in the c cavity and the d cavity is discharged to the outside by the third electromagnetic valve 17 and the seventh electromagnetic valve 21, at this time, the double-layer piston connecting rod 9 moves downwards (along the direction a) under the thrust action of the air, and the exhaust valve moves downwards along with the double-layer piston connecting rod 9 due to the coupling 10 connecting the double-layer piston connecting rod 9 with the exhaust valve. Then, the other part of air in the I-stage constant-pressure air storage device enters the I-stage cylinder 1 (along the direction b 2) along with the opening of the air inlet valve 2, and the piston 4 in the I-stage cylinder 1 is pushed to move from the top dead center to the bottom dead center of the I-stage cylinder 1; at the same time, the exhaust valve 3 is in a closed state at this time.
Second, referring to fig. 4, which shows a schematic diagram of the expansion process of the piston type expansion unit, when the air intake phase is completed, firstly, air is introduced into the corresponding c-chamber and d-chamber of the valve actuator 8 through the third electromagnetic valve 17 and the seventh electromagnetic valve 21, and air in the a-chamber and b-chamber is discharged to the outside through the first electromagnetic valve 15 and the fifth electromagnetic valve 19; then, the controller 7 closes the first electromagnetic valve 15, the second electromagnetic valve 16, the third electromagnetic valve 17, the fourth electromagnetic valve 18, the fifth electromagnetic valve 19, the sixth electromagnetic valve 20, the seventh electromagnetic valve 21 and the eighth electromagnetic valve 22, the air inlet valve 11 does not move any more, the I-stage cylinder 1 is in a closed state, the air in the I-stage cylinder 1 expands to do work, and the piston 4 in the I-stage cylinder 1 is pushed to move downwards (along the direction c) until the piston 4 reaches the bottom dead center.
Thirdly, referring to fig. 5, a schematic diagram of a state of an exhaust process of the piston expansion unit is shown, and as can be seen from the figure, firstly, a double-layer piston connecting rod 9 and an exhaust valve of the stage i exhaust control unit are moved downwards by a controller 7 (the use principle is the same as that of the intake control unit, and the description is omitted here); then, the exhaust valve is opened, and the gas after expansion work in the stage i cylinder 1 is discharged through the exhaust valve 3, at which time the piston 4 moves upward (in the d direction).
The invention can divide the air in the I-level constant-pressure air storage device into two parts and respectively distribute the air to the I-level air cylinder 1, the I-level air inlet control unit or the I-level air outlet control unit.
Specifically, referring to fig. 6, there is shown a schematic perspective view of a level i constant pressure gas storage device, where it can be seen that the level i constant pressure gas storage device includes a storage tank 24, a bidirectional quantitative hydraulic pump 25 and a water tank 26 are disposed on one side of the storage tank 24, and the storage tank 24 is connected in series with the bidirectional quantitative hydraulic pump 25 and the water tank 26. When the I-level constant-pressure gas storage device is used, the bidirectional quantitative hydraulic pump 25 changes the air pressure in the constant-pressure gas storage device by adding or subtracting water into the water tank 26, and the I-level constant-pressure gas storage device is used for providing air with constant pressure into the I-level cylinder 1.
Examples
The embodiment provides a two-stage expansion system, referring to fig. 7, which shows an overall structure schematic diagram of the two-stage expansion system, and as can be seen from the figure, the two-stage expansion system further comprises a stage ii cylinder 27 in addition to a piston expansion unit, an exhaust valve 3 of the stage i cylinder 1 is connected with an intake valve 2 of the stage ii cylinder 27 through a pipeline, a stage ii check valve 28 is connected to the pipeline, and the flow direction of the stage ii check valve 28 is consistent with the flow direction of the stage i check valve 23; the pipeline is connected with a grade II constant pressure gas storage device, the grade II constant pressure gas storage device has the same structure as the grade I constant pressure gas storage device, and mainly plays a role of back pressure, so that the pressure of gas in the pipeline is consistent with the preset pressure of the grade II constant pressure gas storage device, and the pressure of air entering a grade II cylinder 27 is constant; the controller 7 is connected with a II-level air inlet control unit and a II-level air outlet control unit (the II-level air inlet control unit and the II-level air outlet control unit have the same structure as the I-level air inlet control unit and the I-level air outlet control unit), the II-level air inlet control unit and the II-level air outlet control unit are connected to the II-level air cylinder 27, and the II-level air inlet control unit and the II-level air outlet control unit are respectively used for charging air into the II-level air cylinder 27 and discharging air from the II-level air cylinder 27; the II-stage air inlet control unit and the II-stage air outlet control unit are connected with the II-stage constant-pressure air storage device or the I-stage constant-pressure air storage device.
Overall working principle of the two-stage expansion system:
firstly, referring to fig. 3, a controller 7 is used for controlling a stage i air inlet control unit, so that part of air in a stage i constant-pressure air storage device enters the stage i air inlet control unit, and an exhaust valve is pushed to move downwards; then, the other part of air in the I-stage constant-pressure air storage device enters the I-stage air cylinder 1 along with the opening of the air inlet valve 2, the piston 4 in the I-stage air cylinder 1 is pushed to move downwards, and the air outlet valve 3 is in a closed state; when the intake of the stage i cylinder 1 is started, the stage ii cylinder 27 starts the exhaust process.
Secondly, referring to fig. 4, when the air intake stage is completed, the controller 7 controls the stage i air intake control unit to close the air intake valve 2, the stage i air cylinder 1 is in a closed state, air in the stage i air cylinder 1 expands to do work, and the piston 4 in the stage i air cylinder 1 is pushed to move downwards continuously;
then the exhaust valve 3 of the I-stage cylinder 1 is opened, the gas after expansion work in the I-stage cylinder 1 enters the pipeline which is communicated with the I-stage cylinder 1 and the II-stage cylinder 27 through the exhaust valve 3, and according to the hydrostatic transfer principle, as the II-stage constant pressure gas storage device is connected to the pipeline, the gas pressure in the pipeline can reach the gas pressure set by the II-stage constant pressure gas storage device, at the moment, in the II-stage cylinder 27, the first electromagnetic valve 15, the third electromagnetic valve 17, the fifth electromagnetic valve 19 and the seventh electromagnetic valve 21 of the II-stage gas inlet control unit are opened through the controller 7, the second electromagnetic valve 16, the fourth electromagnetic valve 18, the sixth electromagnetic valve 20 and the eighth electromagnetic valve 22 of the II-stage gas inlet control unit are closed, and at the moment, the double-layer piston connecting rod 9 in the valve actuator 8 of the II-stage air inlet control unit moves downwards under the thrust action of air, the corresponding air inlet valve 11 moves downwards along with the double-layer piston connecting rod 9, and the other part of constant-pressure air in the pipelines of the I-stage cylinder 1 and the II-stage cylinder 27 enters the II-stage cylinder 27 along with the opening of the air inlet valve 2 to push the piston 4 in the II-stage cylinder 27 to move from the top dead center to the bottom dead center, and when the II-stage cylinder 27 is in air inlet, the air outlet valve 3 of the II-stage cylinder 27 is in a closed state.
And thirdly, the gas in the II-stage cylinder 27 performs expansion work and the II-stage cylinder 27 performs an exhaust process, wherein the principle is the same as that of the I-stage cylinder 1, and the description is omitted.
According to the invention, through adopting an electric pneumatic variable valve structure, flexible control of the air inlet valve and the air outlet valve is realized, and through arranging a constant-pressure air storage device between the communicating pipelines of the first-stage air cylinder 1 and the second-stage air cylinder 27, the constant pressure of air in the pipeline is ensured, the problems of compressed air resource waste and incomplete expansion and great loss of a single-stage piston 4-type expander and a traditional two-stage piston 4-type expander are solved, and the output power and the energy utilization efficiency of the piston 4-type expander are improved.

Claims (10)

1. A piston expansion unit, characterized by: the device comprises a first-stage cylinder (1), wherein an intake valve (2) and an exhaust valve (3) are arranged on the first-stage cylinder (1), a variable valve distribution control module is arranged on the first-stage cylinder (1), and the variable valve distribution control module controls the opening or closing of the intake valve (2) and the exhaust valve (3); one side of the first-stage cylinder (1) is provided with a first-stage constant-pressure gas storage device which is respectively connected with the air inlet valve (2) and the variable valve air distribution control module.
2. The piston expansion unit of claim 1, wherein: a piston (4) is arranged in the first-stage cylinder (1), one end of the piston (4) is connected with a connecting rod (5), the other end of the connecting rod (5) is connected with a crankshaft (6), and the crankshaft (6) is used for being connected with an output device.
3. The piston expansion unit of claim 1, wherein: the variable valve gas distribution control module comprises a controller (7), wherein the controller (7) is connected with a level I gas inlet control unit and a level I gas outlet control unit, and the level I gas inlet control unit and the level I gas outlet control unit are connected with a level I constant pressure gas storage device; the I-level air inlet control unit and the I-level air outlet control unit are respectively used for inflating the I-level air cylinder (1) and deflating the I-level air cylinder (1).
4. A piston expansion unit according to claim 3, characterized in that: the I-stage air inlet control unit or the I-stage air outlet control unit comprises a valve actuator (8); the valve actuator (8) comprises a cylinder cavity (801), a partition plate (802) is arranged in the cylinder cavity (801), and the partition plate (802) is used for dividing the cylinder cavity (801) into an upper cavity and a lower cavity; the upper part of the partition plate (802) is sealed and is connected with a double-layer piston connecting rod (9) in a sliding manner, the upper baffle part and the lower baffle part of the double-layer piston connecting rod (9) are positioned above and below the partition plate (802), the double-layer piston connecting rod (9) is sealed and slides through the cylinder cavity (801) and is connected with an air inlet valve (11), the air inlet valve (11) movably penetrates through the I-stage cylinder (1), and the air inlet valve (11) is used for blocking or opening the air inlet valve (2).
5. The piston expansion unit of claim 4, wherein: the air inlet valve (11) is provided with a pressing sheet (12), and a pre-tightening spring (13) is arranged at the joint of the pressing sheet (12) and the air cylinder.
6. A piston expansion unit according to claim 3, characterized in that: the I-stage air inlet control unit or the I-stage air outlet control unit also comprises an electromagnetic valve; the electromagnetic valves comprise a first electromagnetic valve (15), a second electromagnetic valve (16), a third electromagnetic valve (17), a fourth electromagnetic valve (18), a fifth electromagnetic valve (19), a sixth electromagnetic valve (20), a seventh electromagnetic valve (21) and an eighth electromagnetic valve (22); the first electromagnetic valve (15), the second electromagnetic valve (16), the third electromagnetic valve (17), the fourth electromagnetic valve (18), the fifth electromagnetic valve (19), the sixth electromagnetic valve (20), the seventh electromagnetic valve (21) and the eighth electromagnetic valve (22) are connected with the controller (7) and the cylinder cavity (801); the first electromagnetic valve (15), the second electromagnetic valve (16) are communicated with a cavity above the upper baffle part of the double-layer piston connecting rod (9), the third electromagnetic valve (17), the fourth electromagnetic valve (18) are communicated with a cavity between the upper baffle part of the double-layer piston connecting rod (9) and the partition plate (802), the fifth electromagnetic valve (19), the sixth electromagnetic valve (20) are communicated with a cavity between the lower baffle part of the double-layer piston connecting rod (9) and the partition plate (802), and the seventh electromagnetic valve (21) and the eighth electromagnetic valve (22) are communicated with a cavity below the lower baffle part of the double-layer piston connecting rod (9); the I-stage constant-pressure gas storage device is connected with a first electromagnetic valve (15), a second electromagnetic valve (16), a third electromagnetic valve (17), a fourth electromagnetic valve (18), a fifth electromagnetic valve (19), a sixth electromagnetic valve (20), a seventh electromagnetic valve (21) and an eighth electromagnetic valve (22).
7. The piston expansion unit of claim 1, wherein: the air outlet end of the I-level constant-pressure air storage device is provided with a I-level one-way valve (23), and the I-level one-way valve (23) is consistent with the outflow direction of working medium in the I-level constant-pressure air storage device.
8. A dual stage expansion system, characterized by: comprising a piston expansion unit according to any of claims 1 to 7, further comprising a stage ii cylinder (27), the exhaust valve (3) of the stage i cylinder (1) being connected to the intake valve (2) of the stage ii cylinder (27) by means of a conduit connected to a stage ii constant pressure gas storage means; the controller (7) is also connected with a II-level air inlet control unit and a II-level air outlet control unit, the II-level air inlet control unit and the II-level air outlet control unit are connected with a II-level air cylinder (27), and the II-level air inlet control unit and the II-level air outlet control unit are respectively used for inflating the II-level air cylinder (27) and deflating the II-level air cylinder (27); the II-stage air inlet control unit and the II-stage air outlet control unit are connected with the II-stage constant-pressure air storage device or the I-stage constant-pressure air storage device.
9. The dual-stage expansion system of claim 8, wherein: the I-level constant-pressure gas storage device or the II-level constant-pressure gas storage device comprises a storage tank (24), one side of the storage tank (24) is provided with a bidirectional quantitative hydraulic pump (25) and a water tank (26), and the storage tank (24) is connected with the bidirectional quantitative hydraulic pump (25) and the water tank (26) in series.
10. The dual-stage expansion system of claim 8, wherein: the pipeline is connected with a second-stage one-way valve (28), and the flow direction of the second-stage one-way valve (28) is consistent with the flow direction of the first-stage one-way valve (23).
CN202310417595.XA 2023-04-19 2023-04-19 Piston type expansion unit and two-stage expansion system Pending CN116428013A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202310417595.XA CN116428013A (en) 2023-04-19 2023-04-19 Piston type expansion unit and two-stage expansion system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202310417595.XA CN116428013A (en) 2023-04-19 2023-04-19 Piston type expansion unit and two-stage expansion system

Publications (1)

Publication Number Publication Date
CN116428013A true CN116428013A (en) 2023-07-14

Family

ID=87085111

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202310417595.XA Pending CN116428013A (en) 2023-04-19 2023-04-19 Piston type expansion unit and two-stage expansion system

Country Status (1)

Country Link
CN (1) CN116428013A (en)

Similar Documents

Publication Publication Date Title
EP1752613B1 (en) Heat energy recovery apparatus
US6470677B2 (en) Free piston engine system with direct drive hydraulic output
JP2527268Y2 (en) Valve train for internal combustion engine
CN209943030U (en) Hydraulically-driven two-stage continuous booster-type ultrahigh-pressure hydrogen compressor main engine
CN202360325U (en) Hydraulic-drive gas compressor
CN101008318A (en) Single piston monopropellant hydraulic free piston engine
JP2012127337A (en) Multistage piston compressor
US9074588B2 (en) Air compression method and apparatus
CN110094319B (en) Multi-cascade double-cylinder linear compressor
CN100545425C (en) The method of operating internal-combustion engines
CN102392810A (en) Hydraulically driven gas compressor
JPH04232319A (en) Non-symmetrical double stabilizing fluid pressurre operation actuator mechanism
CN101566106A (en) Compression stroke realization device of two-stroke hydraulic free piston engine
CN101892942B (en) Single piston hydraulic free-piston engine capable of reducing pumping flow pulsation
CN116428013A (en) Piston type expansion unit and two-stage expansion system
CN104822911A (en) Gas exchange valve arrangement
CN110578732A (en) Energy storage type hydraulic cylinder with built-in welded piston rod
CN213928665U (en) Two-stage compression cylinder capable of doing work in whole course
CN212671889U (en) Marine intelligent integrated low-speed diesel engine electric hydrostatic exhaust valve system
CN107605821A (en) A kind of novel gas-liquid conversion equipment
CN201013547Y (en) Double power compact type gas-liquid blower pump
CN103590902B (en) The motor of low pumping loss and the method for reduction motor pumping loss
CN112576425A (en) Water turbine
CN111472860A (en) Marine intelligent integrated low-speed diesel engine electric hydrostatic exhaust valve system
CN110576134B (en) Free piston air hammer forging system with two working modes of daytime and night

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination