CN114526916B - Stirling engine cylinder pressure detection system and detection method thereof - Google Patents
Stirling engine cylinder pressure detection system and detection method thereof Download PDFInfo
- Publication number
- CN114526916B CN114526916B CN202210421269.1A CN202210421269A CN114526916B CN 114526916 B CN114526916 B CN 114526916B CN 202210421269 A CN202210421269 A CN 202210421269A CN 114526916 B CN114526916 B CN 114526916B
- Authority
- CN
- China
- Prior art keywords
- cylinder
- stirling engine
- crankshaft
- pressure
- phase
- 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.)
- Active
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M15/00—Testing of engines
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L19/00—Details of, or accessories for, apparatus for measuring steady or quasi-steady pressure of a fluent medium insofar as such details or accessories are not special to particular types of pressure gauges
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M15/00—Testing of engines
- G01M15/02—Details or accessories of testing apparatus
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Combined Controls Of Internal Combustion Engines (AREA)
Abstract
The invention relates to the technical field of engines, in particular to a cylinder pressure detection system of a Stirling engine and a detection method thereof, wherein the pressure detection system comprises the Stirling engine, a working medium pressure detection unit and a crankshaft angle measurement unit, connecting pieces are arranged among cylinders of the engine, one end of each connecting piece is communicated with a hot cavity of each cylinder, the other end of each connecting piece is communicated with a cold cavity of an adjacent cylinder, when the connecting pieces are in a communicated state, the hot cavity of each cylinder is communicated with the cold cavity of the adjacent cylinder, and when the connecting pieces are in a blocked state, the hot cavity of each cylinder is disconnected with the cold cavity of the adjacent cylinder; the working medium pressure detection unit is fixed on a detected cylinder of the Stirling engine, and the crankshaft rotation angle measurement unit is fixed on the Stirling engine.
Description
Technical Field
The invention relates to the technical field of engines, in particular to a cylinder pressure detection system of a Stirling engine and a detection method thereof.
Background
The Stirling engine is a typical external combustion engine and has the characteristics of smooth combustion, wide fuel adaptability, low vibration noise and the like. The fuel is continuously combusted in the combustion chamber outside the cylinder of the Stirling engine, the acting load of the piston is close to a sine wave, so that knocking and intermittent combustion are avoided, the quality advantage in the aspect of low vibration noise is obvious, and the Stirling engine is continuously applied to military and civil fields such as underwater power, landfill power generation, combined heat and power supply and the like from the beginning of the eighties of the last century.
In order to facilitate the research on the combustion process, the heat transfer process between gas and cylinder wall and the processes of air intake and exhaust in the cylinder of a cylinder engine, the cylinder pressure of a traditional internal combustion engine (such as a diesel engine) is generally reflected by a P-phi indicator diagram (P is the pressure of a cylinder working medium, and phi is a crank angle), and the P-phi indicator diagram reflects the thermodynamic conversion process of output mechanical work. The cylinder pressure can be used for researching that the engine pressure is an important basis for calculating engine performance parameters (such as indicated power, explosion pressure, compression pressure and the like) and in-cylinder temperature and the like, and is also an evaluation parameter of an engine heat release rule analysis and combustion process simulation calculation model, and the monitoring and diagnosis of the working state of the engine can be realized by using a cylinder pressure signal. In general, the cylinder working fluid pressure P is measured by a pressure sensor mounted on the cylinder, and the crank angle phi is measured by a flywheel ring gear directly connected thereto.
Meanwhile, the top dead center is a relative reference of the operation position of the crankshaft, and in the test of the pressure of the engine cylinder, the top dead center phase of a P-phi indicator diagram needs to be aligned, and the top dead center aligning method comprises a static top dead center positioning method and a pure compression line method. The static upper dead center positioning method is simple to operate, but because the engine is acted by the gas pressure in the cylinder and the reciprocating inertia force during the operation, the transmission mechanism is easy to generate stress deformation, so that the upper dead center position of the engine during the operation and the position during the static measurement have a certain difference, the static upper dead center positioning method ignores the deformation of the transmission mechanism, and the measurement precision is also influenced by the magnetic wedge and the installation precision of the sensor. The pure compression line method is characterized in that fuel oil injection of a certain cylinder of the engine is stopped, the pressure of the pure compression cylinder and a top dead center pulse signal and a crank angle signal of a flywheel end are synchronously measured, a difference value between a crank angle position corresponding to the peak value of the pressure of the cylinder and the top dead center pulse signal is obtained, and the top dead center pulse signal is corrected during subsequent cylinder pressure measurement. The pure compression line method considers the influence of factors such as measurement errors caused by load and sensor installation, and the measurement precision is high.
However, the stirling engine belongs to a closed cycle engine, the structure of the stirling engine is different from that of a traditional internal combustion engine, a plurality of cylinders are arranged in the engine, pistons are arranged in the cylinders and are connected with a crankshaft through connecting rods, coolers are arranged among the cylinders, the pistons separate the upper side and the lower side of each cylinder to form a hot cavity and a cold cavity, the pistons reciprocate under the action of working medium pressure difference in the hot cavities and the cold cavities to drive the crankshaft to rotate, and the hot cavities of the cylinders are communicated with the cold cavities of adjacent cylinders through the coolers, so that the cylinders are communicated in sequence, and the pure compression line test cannot be carried out to find the phase of the top dead center of the cylinder by stopping a certain cylinder of the engine from injecting fuel into the cylinder like the traditional internal combustion engine (such as a diesel engine). Meanwhile, a crankshaft of the stirling engine is arranged in a crankcase, an output shaft of the engine is arranged in parallel with the crankshaft, a flywheel is arranged at the end of the output shaft, a driving gear is fixed on the crankshaft, a driven gear meshed with the driving gear is fixed on the output shaft, and the crankshaft drives the output shaft to rotate through the driving gear and the driven gear.
Disclosure of Invention
The invention aims to overcome the technical defects, provides a cylinder pressure detection system of a Stirling engine and a detection method thereof, and solves the technical problem that the performance analysis and the dynamic characteristic analysis of the Stirling engine are inconvenient due to the fact that the relation between the cylinder pressure and the crank angle is difficult to obtain when the top dead center of the Stirling engine is taken as a reference in the prior art.
In order to achieve the technical purpose, the technical scheme of the invention provides a cylinder pressure detection system of a Stirling engine, which comprises the Stirling engine, a working medium pressure detection unit and a crankshaft angle measurement unit, wherein connecting pieces are arranged among cylinders of the Stirling engine, one end of each connecting piece is communicated with a hot cavity of each cylinder, the other end of each connecting piece is communicated with a cold cavity of an adjacent cylinder, each connecting piece is a plugging piece with a plugging state or a communicating piece with a communicating state, when the connecting pieces are plugging pieces, the hot cavity of each cylinder is disconnected with the cold cavity of the adjacent cylinder, and when the connecting pieces are communicating pieces, the hot cavity of each cylinder is communicated with the cold cavity of the adjacent cylinder;
the working medium pressure detection unit is fixed on a detected cylinder of the Stirling engine and is used for measuring the working medium pressure in the heat cavity of each detected cylinder;
the crankshaft angle measuring unit is fixed on the Stirling engine and used for measuring the angle of the crankshaft corresponding to the measured cylinder.
Optionally, the crank angle measuring unit includes a rotating disc and an angle sensor, the rotating disc is mounted at an end of the crank shaft corresponding to the cylinder to be measured, the angle sensor is fixed on an end cover of a crank case of the stirling engine and located at one side of the rotating disc, and the angle sensor is configured to sense rotation of the rotating disc and generate an angle signal when the rotating disc rotates.
Optionally, the corner sensor is photoelectric encoder, photoelectric encoder is fixed in on the end cover of crankcase and be located one side of rolling disc, the rolling disc is close to one side of photoelectric encoder is fixed with the dwang, the dwang with photoelectric encoder's rotor is connected, can drive when the dwang rotates photoelectric encoder's rotor rotates.
Optionally, the crank angle measuring unit further includes a static top dead center alignment assembly, the static top dead center alignment assembly includes a proximity sensor and an induction block, the induction block is fixed on the rotating disc, the proximity sensor is installed on the end cover of the crankcase and located on one side of a rotation path of the induction block, the proximity sensor is used for sensing the induction block, and when the induction block rotates to one side of the proximity sensor, the piston of the cylinder to be measured is located at the static top dead center of the piston of the cylinder to be measured.
Optionally, a first positioning module is disposed on a surface of the crankshaft, a second positioning module which can rotate around the first positioning module along with rotation of the rotating disc is disposed on the rotating disc, when the first positioning module is in butt joint with the second positioning module, a phase of the sensing block is the same as a phase of a piston of the cylinder to be measured, a position of the end cover of the crankcase, which is opposite to the end of the crankshaft, is a central position of the end cover of the crankcase, and a direction of a connecting line between the central position of the end cover of the crankcase and the proximity sensor is the same as a direction of the piston of the cylinder to be measured moving toward a top dead center of the piston.
Optionally, the rotating disc includes a balance disc and an adjusting disc, one side of the balance disc is fixed to the end of the crankshaft, the adjusting disc is fixed to the other side of the balance disc, and a balance gap for balancing the rotation of the rotating disc is formed in the circumferential direction of the balance disc.
Optionally, the balance disc is detachably connected to the adjustment disc, a first phase positioning hole is formed in the surface of the adjustment disc, a plurality of second phase positioning holes are formed in the circumferential direction of the balance disc at intervals, each second phase positioning hole corresponds to a phase of a piston of each cylinder, and when the first phase positioning hole is in butt joint with the second phase positioning hole corresponding to the piston of the cylinder to be measured, a phase of the induction block is the same as a phase of the piston of the cylinder to be measured.
Optionally, one side that the adjustment disk is close to the balance disk is fixed with the location arch, the one side that the balance disk is close to the adjustment disk is provided with the positioning groove with the protruding adaptation of location, the protruding rotation of location connect in the positioning groove.
Compared with the prior art, the cylinder pressure detection system of the Stirling engine provided by the invention has the beneficial effects that: the Stirling engine is provided with a crank angle measuring unit, a working medium pressure detecting unit is fixed on a detected cylinder of the Stirling engine, and meanwhile, connecting pieces are arranged among cylinders of the engine and are plugging pieces in a plugging state or communicating pieces in a communicating state; when the pressure of a cylinder to be detected of the Stirling engine is detected, firstly, the connecting piece is switched to a blocking state, so that the working medium pressure detection unit measures the pressure of a hot cavity of the cylinder to be detected in the blocking state, meanwhile, the crankshaft angle measurement unit measures the angle of the crankshaft corresponding to the cylinder to be detected, and further the phase value of the crankshaft corresponding to the cylinder to be detected when the pressure of the hot cavity of the cylinder to be detected is at the maximum value can be obtained, wherein the crankshaft phase value is the crankshaft phase value of the dynamic top dead center of the piston of the cylinder to be detected; and then the connecting piece is switched to a communicated state, each cylinder of the Stirling engine operates in a normal state, the working medium pressure detection unit measures the pressure of the hot cavity of the measured cylinder in the normal state, the crank angle measurement unit measures the rotation angle of the crank shaft corresponding to the measured cylinder to obtain an indicator diagram of the pressure of the hot cavity of the measured cylinder and the rotation angle of the crank shaft, and further obtain the relation between the pressure of the hot cavity and the rotation angle of the crank shaft by taking the phase of the dynamic top dead center of the piston of the measured cylinder as the reference, so that the pressure of the cylinder of the Stirling engine is finally detected, and convenience is provided for performance analysis and dynamic characteristic analysis of the Stirling engine.
In order to achieve the technical purpose, the technical scheme of the invention provides a method for detecting the cylinder pressure of a Stirling engine, which is executed by a Stirling engine cylinder pressure detection system and comprises the following steps:
s100: switching the connecting piece into a blocking piece to enable each cylinder of the Stirling engine to operate in a blocking state;
s200: acquiring the pressure of a hot cavity in the cylinder to be detected through the pressure detection unit, and acquiring a crank angle corresponding to the cylinder to be detected through the crank angle measurement unit to obtain a crank phase value of a dynamic top dead center corresponding to the maximum hot cavity pressure of the cylinder to be detected;
s300: switching the connecting piece into a communicating piece to enable each cylinder of the Stirling engine to operate in a normal state;
s400: acquiring the pressure of a hot cavity in the cylinder to be detected through the pressure detection unit, and acquiring a corner of the crankshaft corresponding to the cylinder to be detected through the crankshaft corner measurement unit so as to obtain hot cavity pressure values of the cylinder to be detected corresponding to each phase of the crankshaft when the cylinder to be detected works normally;
s500: and taking the crankshaft phase value of the dynamic top dead center as a base point to obtain an indicator diagram of the relation between the pressure of the hot cavity of the measured cylinder and the crankshaft rotation angle.
Optionally, in the step S400, when the rotating disc rotates, the proximity sensor senses a sensing block to obtain a crankshaft phase value corresponding to a maximum pressure of each cylinder when the cylinder to be measured normally operates.
Compared with the prior art, the method for detecting the cylinder pressure of the Stirling engine has the beneficial effects that: according to the cylinder pressure detection method, the working medium pressure detection unit is used for measuring the pressure of a hot cavity of a detected cylinder in a blocking state, the crankshaft corner measurement unit is used for measuring the corner of a crankshaft corresponding to the detected cylinder, and therefore the crankshaft phase value of the piston dynamic top dead center of the detected cylinder can be obtained; the working medium pressure detection unit is used for measuring the pressure of a hot cavity of the measured cylinder in a normal working state, the crank angle measurement unit is used for measuring the corner of the crank shaft corresponding to the measured cylinder, an indicator diagram of the pressure of the hot cavity of the measured cylinder and the corner of the crank shaft is obtained, the relation between the pressure of the hot cavity and the corner of the crank shaft taking the phase of the dynamic top dead center of the piston of the measured cylinder as the reference is further obtained, the detection of the pressure of the cylinder of the Stirling engine is finally realized, and convenience is provided for performance analysis and dynamic characteristic analysis of the Stirling engine.
Drawings
Fig. 1 is a schematic structural diagram of a cylinder pressure detection system of a stirling engine provided in embodiment 1 of the present invention.
Fig. 2 is a schematic structural diagram of a working medium circulation unit of a cylinder pressure detection system of a stirling engine provided in embodiment 1 of the present invention.
Fig. 3 is a schematic structural diagram of a crank angle measuring unit of a cylinder pressure detecting system for a stirling engine according to embodiment 1 of the present invention.
Fig. 4 is an exploded view of a crank angle measuring unit of the cylinder pressure detecting system for the stirling engine provided in embodiment 1 of the present invention.
Fig. 5 is a schematic structural view of a crank angle measuring unit of a stirling engine cylinder pressure detecting system according to embodiment 1 of the present invention in an assembled state.
Fig. 6 is a side view of a crank angle measuring unit of a stirling engine cylinder pressure detecting system according to embodiment 1 of the present invention in an assembled state.
Fig. 7 is a cross-sectional view taken along line a-a of fig. 6.
Fig. 8 is a P-phi indicator diagram based on the static top dead center and the dynamic top dead center provided in embodiment 1 of the present invention.
Fig. 9 is a flowchart of a stirling engine cylinder pressure detection method according to embodiment 2 of the present invention.
Wherein, in the figures, the various reference numbers:
10-Stirling engine 11-cylinder 12-connecting piece
13-crankshaft 14-crankcase 15-output shaft
16-flywheel 20-crankshaft angle measuring unit 21-rotating disk
22-static top dead center alignment assembly 111-piston 112-thermal chamber
113-cold chamber 114-connecting rod 131-driving gear
132-first positioning module 141-end cover 151-driven gear
211-balance disc 212-adjusting disc 213-second positioning module
221-proximity sensor 222-sensing block 2111-equilibrium gap
2112 second phase location hole 2113 positioning groove 2121 rotating rod
2122 first phase positioning hole 2123 and positioning boss.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not limit the invention.
The invention provides a cylinder pressure detection system of a Stirling engine and a detection method thereof.
Example 1:
embodiment 1 of the present invention provides a cylinder pressure detection system of a stirling engine, as shown in fig. 1-2, including a stirling engine 10, a working medium pressure detection unit (not identified in the figure) and a crank angle measurement unit 20, a connection member 12 is disposed between cylinders 11 of the stirling engine 10, one end of the connection member 12 is communicated with a hot chamber 112 of each cylinder 11, the other end of the connection member 12 is communicated with a cold chamber 113 of an adjacent cylinder 11, the connection member 12 is a communication member with a communication state or a blocking member with a blocking state, when the connection member 12 is a communication member, the hot chamber 112 of each cylinder 11 is communicated with the cold chamber 113 of the adjacent cylinder 11, and when the connection member 12 is a blocking member, the hot chamber 112 of each cylinder 11 is disconnected from the cold chamber 113 of the adjacent cylinder 11; the working medium pressure detection unit is fixed on the cylinders to be detected and is used for measuring the working medium pressure in the hot cavity 112 of each cylinder to be detected; the crank angle measuring unit 20 is fixed to the stirling engine 10 and measures the angle of rotation of the crankshaft 13 corresponding to the cylinder to be measured.
In this embodiment, as shown in fig. 1 to 2, two working units are disposed inside the stirling engine 10, each working unit includes four cylinders 11, a piston 111 is disposed in each cylinder 11, the piston 111 is connected to a crankshaft 13 through a connecting rod 114, the piston 111 partitions upper and lower sides of the cylinder 11 into a hot chamber 112 and a cold chamber 113, the piston 111 can reciprocate in the cylinder 11 to drive the crankshaft 13 to rotate, the crankshaft 13 of the stirling engine 10 is disposed in a crankcase 14, an output shaft 15 of the engine is disposed parallel to the crankshaft 13, a flywheel 16 is mounted at an end of the output shaft 15, a driving gear 131 is fixed on the crankshaft 13, a driven gear 151 engaged with the driving gear 131 is fixed on the output shaft 15, and the crankshaft 13 drives the output shaft 15 to rotate through the driving gear 131 and the driven gear 151, thereby driving the flywheel 16 to rotate.
Specifically, a crank angle measuring unit 20 is arranged on the Stirling engine 10, a working medium pressure detecting unit is fixed on a detected cylinder of the Stirling engine 10, and a connecting piece 12 with a communication state and a blocking state is arranged between cylinders 11 of the engine; when the pressure of a cylinder to be detected of the Stirling engine 10 is detected, firstly, the connecting piece 12 is switched to a blocking state, the Stirling engine 10 is dragged backwards by the motor, each cylinder 11 of the Stirling engine 10 operates in the blocking state, the working medium pressure detection unit measures the pressure P of the hot cavity 112 of the cylinder to be detected in the blocking state, meanwhile, the crankshaft rotation angle measurement unit 20 measures the rotation angle phi of the crankshaft 13 corresponding to the cylinder to be detected, a pure compression line of the relation between the pressure of the hot cavity 112 and the rotation angle phi of the crankshaft 13 in the blocking state of the cylinder to be detected is obtained, the rotation angle corresponding to the crankshaft 13 under the maximum pressure of the hot cavity 112 of the cylinder to be detected can be reflected on the pure compression line, and the crankshaft phase value 13 is the crankshaft phase value of the dynamic top dead center of the piston 111 of the cylinder to be detected; and then the connecting piece 12 is switched to a communication state, each cylinder 11 of the Stirling engine 10 operates in a normal state, the working medium pressure detection unit measures the pressure P of the hot cavity 112 of the measured cylinder in the normal state, the crank angle measurement unit 20 measures the crank angle phi of the crank shaft 13 corresponding to the measured cylinder to obtain a P-phi indicator diagram of the pressure P of the hot cavity 112 of the measured cylinder and the crank angle phi of the crank shaft 13, and further obtain the relation between the pressure P of the hot cavity 112 and the crank angle phi of the crank shaft 13 by taking the phase of the dynamic top dead center of the piston 111 of the measured cylinder as the reference, so that the pressure of the cylinder 11 of the Stirling engine 10 is finally detected, and convenience is provided for performance analysis and dynamic characteristic analysis of the Stirling engine 10.
In this embodiment, the connecting element 12 is a plugging element or a cooler of the stirling engine 10, and when the state of the connecting element 12 is switched, only the plugging element and the cooler need to be switched and installed, where two separated cavities separated by a partition plate are provided inside the plugging element, and when the plugging element is installed, one of the separated cavities is communicated with the hot cavity 112 of each cylinder 11, the other separated cavity is communicated with the cold cavity 113 of the adjacent cylinder 11, and the hot cavities 112 and the cold cavities 113 of the two adjacent cylinders 11 are separated by the partition plate, so as to finally plug the hot cavities 112 and the cold cavities 113 of the two adjacent cylinders 11; the cooler is an original cooler of the Stirling engine 10, and when the cooler is installed between the cylinders 11, the hot cavity 112 and the cold cavity 113 of two adjacent cylinders 11 are communicated.
In this embodiment, the thermal cavity 112 of each cylinder 11 is connected with the combustion chamber of the stirling engine 10, and each cylinder 11 and each connecting piece 12 constitute a working medium circulation unit of the stirling engine 10; taking the four-cylinder stirling engine 10 as an example, when the connecting piece 12 is a plugging device, the working medium circulation unit is in a plugging state, the four plugging devices separate the working medium circulation unit and form four closed hot cavities 112 and four closed cold cavities 113, the maximum pressures of the four hot cavities 112 and the four cold cavities 113 are the same, and since the working medium circulation unit in the plugging state cannot adjust the pressure of the hot cavity 112 and can only balance by the pumping action of the ring of the piston 111, the problems of high pressure ratio and severe vibration are likely to be caused, therefore, the pure compression line detection should be performed under the low working condition (the highest working medium pressure is not more than 5MPa, and the rotating speed is not more than 1000 r/min) of the stirling engine 10. Meanwhile, as the cylinder sleeve water cavity is not cooled by cooling water, the working condition of the 111 rings of the piston is relatively bad, and the time of single test is ensured to be within 3 min. The cold chamber 113 can be cooled by cooling water to ensure that the temperature of the working medium in the cold chamber 113 is low. If the temperature of the thermal chamber 112 is high, the fan is used for cooling.
After the working medium circulation unit reaches a preset stable state, the Stirling engine 10 is dragged backwards through the motor, data are recorded and stored (the operation time of the engine is guaranteed within 3 min), and a pure compression line of the Stirling engine 10 is obtained.
In this embodiment, the working medium pressure detection unit is a pressure sensor.
It is understood that the crank angle measuring unit may calculate the rotation angle of the crankshaft 13 by measuring the rotation angle of the flywheel 16 and then calculating the rotation angle of the crankshaft 13 based on the gear ratio of the driving gear 131 on the crankshaft 13 and the driven gear 151 of the output shaft 15. Or by directly measuring the rotational angle of the crankshaft 13.
Alternatively, as shown in fig. 3 to 7, the crank angle measuring unit 20 includes a rotary disc 21 and an angle sensor (not shown), the rotary disc 21 is mounted at an end portion of the crankshaft 13 corresponding to the cylinder to be measured, the angle sensor is fixed to an end cover 141 of the crankcase 14 of the stirling engine 10 and is located at one side of the rotary disc 21, and the angle sensor is configured to sense rotation of the rotary disc 21 and generate an angle signal when the rotary disc 21 rotates. Specifically, by providing the rotating disk 21 at the end of the crankshaft 13 and providing the rotation angle sensor for measuring the rotation angle of the rotating disk 21 on the end cover 141 of the crankcase 14, accurate measurement of the rotation angle of the crankshaft 13 corresponding to the measured rod body can be achieved.
In this embodiment, the rotation angle sensor may be a hall sensor, the hall sensor is located on one side of the protruding teeth by arranging a plurality of protruding teeth at regular intervals on the periphery of the rotating disc 21, and the hall sensor senses the protruding teeth to obtain the rotation angle of the rotating disc 21. The rotation angle sensor can also be a photoelectric encoder, and a rotor in the photoelectric encoder is driven to rotate when the rotary disc rotates, so that the rotation angle of the rotary disc 21 is obtained.
Optionally, as shown in fig. 3 to 7, the rotation angle sensor is a photoelectric encoder, the photoelectric encoder is fixed on the end cover 141 of the crankcase 14 and located on one side of the rotating disc 21, a rotating rod 2121 is fixed on one side of the rotating disc 21 close to the photoelectric encoder, the rotating rod 2121 is connected to a rotor of the photoelectric encoder, and the rotating rod 2121 can drive the rotor of the photoelectric encoder to rotate when rotating.
Specifically, when the rotating disc 21 rotates, the rotating rod 2121 is driven to rotate, when the rotating rod 2121 rotates, the rotor of the photoelectric encoder is driven to rotate, when the rotor of the photoelectric encoder rotates, the number of square wave signals generated by the photoelectric encoder when the rotating rod 2121 rotates for one cycle is sent to the signal acquisition system, the number of square wave signals generated by the photoelectric encoder when the rotating rod 2121 rotates for one cycle is set as n, when the rotating rod 2121 rotates for 360/n degrees (indicated by a letter a), the photoelectric encoder generates one square wave signal, the n square wave signals are sequenced by natural numbers 1, 2, 3, 1.. and n, the maximum value of the pressure of the thermal cavity 112 in the blocking state is obtained by a pure compression line of the relationship between the pressure of the thermal cavity 112 in the blocking state of the cylinder and the rotation angle of the crankshaft 13, and the serial number of the square wave signal corresponding to the maximum pressure of the thermal cavity 112 is obtained by the pure compression line, multiplying the serial number by a to obtain a crankshaft 13 phase position alpha corresponding to the dynamic top dead center of the tested cylinder of the crankshaft 13, and then taking the crankshaft 13 phase position alpha corresponding to the dynamic top dead center of the tested cylinder 11 as a base point to prepare a P-phi indicator diagram of the pressure P of the hot cavity 112 of the tested cylinder and the rotation angle phi of the crankshaft 13 shown in the figure 8, so as to facilitate performance analysis and dynamic characteristic analysis of the Stirling engine 10.
Optionally, as shown in fig. 3 to 7, the crank angle measuring unit 20 further includes a static top dead center aligning assembly 22, the static top dead center aligning assembly 22 includes a proximity sensor 221 and a sensing block 222, the sensing block 222 is fixed on the rotating disc 21, the proximity sensor 221 is mounted on the end cover 141 of the crankcase 14 and is located at one side of a rotation path of the sensing block 222, the proximity sensor 221 is used for sensing the sensing block 222, and when the sensing block 222 rotates to the side close to the sensor 221, the piston 111 of the cylinder to be measured is located at the static top dead center of the piston 111 of the cylinder to be measured.
Specifically, when the proximity sensor 221 senses that the sensing block 222 rotates to one side of the proximity sensor 221, the proximity sensor 221 generates a sensing signal, a serial number of a crankshaft 13 rotation angle corresponding to a square wave signal generated by the proximity sensor 221 is found, the serial number is multiplied by a to obtain a crankshaft 13 phase β corresponding to a static top dead center of the cylinder to be measured, and an indicator diagram of the pressure of the cylinder thermal cavity 112 to be measured and the rotation angle of the crankshaft 13, which is shown in fig. 8, is prepared based on the crankshaft 13 phase β corresponding to the static top dead center of the cylinder 11 to be measured, so as to study the combustion characteristics of the stirling engine 10.
By combining the dynamic top dead center positioning and the static top dead center positioning, the cylinder pressure test can be performed according to different selectivity of the type and the structure of the Stirling engine 10, and the phase difference between the static top dead center and the dynamic top dead center can also be obtained simultaneously, so that the signal acquisition precision is improved, high-precision equal-crank-shaft 13-corner signals are directly generated, the signal processing difficulty is greatly reduced, the high-precision Stirling engine 10 cylinder pressure signals are finally obtained, and a good technical support is provided for the performance analysis and the dynamic characteristic analysis of the Stirling engine 10.
In this embodiment, the proximity sensor 221 is a hall sensor.
Optionally, as shown in fig. 3 to 7, a first positioning module 132 is disposed on a surface of the crankshaft 13, a second positioning module 213 that can rotate around the first positioning module 132 along with rotation of the rotating disc 21 is disposed on the rotating disc 21, when the first positioning module 132 is in butt joint with the second positioning module 213, a phase of the sensing block 222 is the same as a phase of the piston 111 of the cylinder to be measured, a position of the end cover 141 of the crankcase 14 that is opposite to the end of the crankshaft 13 is a central position of the end cover 141 of the crankcase 14, and a direction of a connection line between the central position of the end cover 141 of the crankcase 14 and the proximity sensor 221 is the same as a direction of the piston 111 of the cylinder to be measured moving toward a top dead center of the piston 111.
Specifically, when the rotating disc 21 is installed, the first positioning module 132 is abutted with the second positioning module 213, that is, the phase of the sensing block 222 is the same as the phase of the piston 111 of the cylinder to be measured, and meanwhile, since the connection line between the proximity sensor 221 and the central portion of the end cover 141 of the crankcase 14 is the same as the direction of the piston 111 of the cylinder to be measured moving towards the top dead center of the piston 111, when the proximity sensor 221 senses the sensing block 222, the rotation angle of the crankshaft 13 corresponding to the sensing signal generated by the proximity sensor 221 is the rotation angle of the crankshaft 13 when the piston 111 of the cylinder to be measured moves to the top of the cylinder to be measured (i.e., the static top dead center), thereby measuring the rotation angle of the crankshaft 13 corresponding to the static top dead center of the cylinder to be measured.
In this embodiment, as shown in fig. 7, the first positioning module 132 and the second positioning module 213 are both positioning pin holes, and when the rotating disc 21 is mounted, the positioning pin holes on the rotating disc 21 are butted with the positioning pin holes on the crankshaft 13, so that the phase of the sensing block 222 can be the same as the phase of the piston 111 of the cylinder to be measured, and then the rotating disc 21 can be fixed by the positioning pins.
In this embodiment, the positioning pin holes on the crankshaft 13 and the position of the sensing block 222 on the rotating disc 21 are determined by program calculation.
Optionally, as shown in fig. 3 to 7, the rotating disc 21 includes a balance disc 211 and an adjusting disc 212, one side of the balance disc 211 is fixed to the end of the crankshaft 13, the adjusting disc 212 is fixed to the other side of the balance disc 211, and a balance notch 2111 for balancing the rotation of the rotating disc 21 is provided in the circumferential direction of the balance disc 211. Specifically, the balance notch 2111 can effectively balance the centrifugal moment of inertia and the reciprocating moment of inertia of the transmission mechanism.
In this embodiment, as shown in fig. 4 and 7, a positioning protrusion 2123 is fixed at a central portion of one surface of the adjusting plate 212 close to the balancing plate 211, one surface of the balancing plate 211 close to the adjusting plate 212 is provided with a positioning groove 2113 adapted to the positioning protrusion 2123, and the positioning protrusion 2123 is rotatably connected in the positioning groove 2113. The positioning protrusions 2123 and the positioning grooves 2113 are arranged to effectively provide positioning for the installation of the adjustment disc 212, and facilitate the rotation of the adjustment disc 212.
Optionally, as shown in fig. 3 to 5, the balance disc 211 is detachably connected to the adjustment disc 212, a first phase positioning hole 2122 is disposed on a surface of the adjustment disc 212, a plurality of second phase positioning holes 2112 are disposed at intervals in a circumferential direction of the balance disc 211, each second phase positioning hole 2112 corresponds to a phase of the piston 111 of each cylinder 11, and when the first phase positioning hole 2122 is in butt joint with the second phase positioning hole 2112 corresponding to the piston 111 of the cylinder to be measured, a phase of the sensing block 222 is the same as a phase of the piston 111 of the cylinder to be measured.
Specifically, after the balance disc 211 is fixed at the end of the crankshaft 13, the adjustment disc 212 is rotated, so that the first phase positioning hole 2122 is butted with the second phase positioning hole 2112 corresponding to the piston 111 of the cylinder to be measured, and further, the first phase positioning hole 2122 is butted with the second phase positioning hole 2112 corresponding to the piston 111 of the cylinder to be measured, and by rotating the adjustment disc 212, not only can the adjustment disc 212 be rapidly positioned, but also when measuring the static top dead center phase of another cylinder, the adjustment disc 212 is only rotated, so that the first phase positioning hole 2122 is butted with the second phase positioning hole 2112 corresponding to the cylinder, so that the phase of the sensing block 222 is the same as the phase of the piston in the cylinder, and the crank angle measuring unit 20 is adapted to detect the static top dead centers of different pistons.
In this embodiment, as shown in fig. 3 to 4, the number of the first phase positioning holes 2122 is 6, when the 6 first phase positioning holes 2122 are butted with the 6 second phase positioning holes 2112 corresponding to the piston 111 of the cylinder to be measured in all the second phase positioning holes 2112 on the balance disc 211, the phase of the induction block 222 is the same as the phase of the piston 111 of the cylinder to be measured, and the adjusted adjustment disc 212 is fixed through the 6 first phase positioning holes 2122. Through the arrangement of the 6 first phase positioning holes 2122, the balance disc 211 and the adjusting disc 212 can be stabilized.
Example 2:
embodiment 2 of the present invention provides a stirling engine cylinder pressure detection method, which is performed by a stirling engine cylinder pressure detection system, and includes the following steps:
s100: switching the connecting piece 12 into a blocking piece to enable each cylinder 11 of the Stirling engine 10 to operate in a blocking state;
s200: acquiring the pressure of a thermal cavity in the cylinder to be detected through the pressure detection unit, and acquiring a rotation angle of the crankshaft corresponding to the cylinder to be detected through the crankshaft rotation angle measurement unit 20 to obtain a crankshaft phase value of a dynamic top dead center corresponding to the maximum thermal cavity pressure of the cylinder to be detected;
s300: switching the connecting member 12 to a communicating member to allow each cylinder 11 of the stirling engine 10 to operate in a normal state;
s400: acquiring the pressure of a hot cavity in the cylinder to be detected through the pressure detection unit, and acquiring the rotation angle of the crankshaft corresponding to the cylinder to be detected through the crankshaft rotation angle measurement unit 20, so as to obtain hot cavity pressure values of the cylinder to be detected corresponding to each phase of the crankshaft when the cylinder to be detected works normally;
s500: and taking the crankshaft phase value of the dynamic top dead center as a base point to obtain an indicator diagram of the relation between the pressure of the hot cavity of the measured cylinder and the crank angle.
Specifically, the cylinder pressure detection method measures the pressure of the hot cavity 112 of the measured cylinder in a blocking state through the working medium pressure detection unit, and measures the rotation angle of the crankshaft 13 corresponding to the measured cylinder through the crankshaft rotation angle measurement unit 20, so as to obtain the crankshaft phase value of the dynamic top dead center of the piston 111 of the measured cylinder; the working medium pressure detection unit is used for measuring the pressure of the thermal cavity 112 of the measured cylinder in a normal working state, the crankshaft angle measurement unit 20 is used for measuring the angle of the crankshaft 13 corresponding to the measured cylinder, an indicator diagram of the pressure of the thermal cavity 112 of the measured cylinder and the angle of the crankshaft 13 is obtained, further, the relation between the pressure of the thermal cavity 112 and the angle of the crankshaft 13 with the phase position of the dynamic top dead center of the piston 111 of the measured cylinder as the reference is obtained, the detection of the pressure of the cylinder 11 of the Stirling engine 10 is finally realized, and convenience is provided for performance analysis and dynamic characteristic analysis of the Stirling engine 10.
Optionally, in step S400, when the rotating disc 21 rotates, the proximity sensor 221 senses the sensing block 222 to obtain the phase value of the crankshaft 13 corresponding to the maximum pressure of each cylinder 11 when the cylinder to be measured normally operates.
In this embodiment, when the rotating disc 21 is installed, the first positioning module 132 is abutted to the second positioning module 213, and the first phase positioning hole 2122 is abutted to the second phase positioning hole 2112 corresponding to the piston 111 of the cylinder to be measured, so that the phase of the sensing block 222 is the same as the phase of the piston 111 of the cylinder to be measured.
The above-described embodiments of the present invention should not be construed as limiting the scope of the present invention. Any other corresponding changes and modifications made according to the technical idea of the present invention should be included in the protection scope of the claims of the present invention.
Claims (6)
1. A Stirling engine cylinder pressure detection system comprises a Stirling engine and is characterized by further comprising a working medium pressure detection unit and a crankshaft angle measurement unit, wherein a connecting piece is arranged between cylinders of the Stirling engine, one end of the connecting piece is communicated with a hot cavity of each cylinder, the other end of the connecting piece is communicated with a cold cavity of an adjacent cylinder, the connecting piece is a plugging piece with a plugging state or a communicating piece with a communicating state, when the connecting piece is a plugging piece, the hot cavity of each cylinder is disconnected with the cold cavity of the adjacent cylinder, and when the connecting piece is a communicating piece, the hot cavity of each cylinder is communicated with the cold cavity of the adjacent cylinder;
the working medium pressure detection unit is fixed on a detected cylinder of the Stirling engine and is used for measuring the working medium pressure in the heat cavity of each detected cylinder;
the crankshaft rotation angle measuring unit is fixed on the Stirling engine and is used for measuring the rotation angle of the crankshaft corresponding to the measured cylinder;
the crank angle measuring unit comprises a static top dead center alignment assembly, a rotating disc and an angle sensor, the rotating disc is installed at the end part of the crank shaft corresponding to the measured cylinder, the angle sensor is fixed on an end cover of a crank case of the Stirling engine and located on one side of the rotating disc, and the angle sensor is used for sensing the rotation of the rotating disc and generating an angle signal when the rotating disc rotates; the static top dead center alignment assembly comprises a proximity sensor and an induction block, the induction block is fixed on the rotating disc, the proximity sensor is mounted on an end cover of the crankcase and located on one side of a rotating path of the induction block, the proximity sensor is used for inducing the induction block, and when the induction block rotates to one side of the proximity sensor, a piston of the cylinder to be measured is located at the static top dead center of the piston of the cylinder to be measured;
a first positioning module is arranged on the surface of the crankshaft, a second positioning module which can rotate around the first positioning module along with the rotation of the rotating disc is arranged on the rotating disc, when the first positioning module is in butt joint with the second positioning module, the phase of the induction block is the same as that of a piston of the cylinder to be measured, a position, opposite to the end part of the crankshaft, on an end cover of the crankcase is a central position of the end cover of the crankcase, and the direction of a connecting line of the central position of the end cover of the crankcase and the proximity sensor is the same as the direction of the piston of the cylinder to be measured moving towards the top dead center of the piston;
the rotating disc comprises a balance disc and an adjusting disc, one side of the balance disc is fixed at the end of the crankshaft, the adjusting disc is fixed at the other side of the balance disc, the balance disc is detachably connected with the adjusting disc, a first phase positioning hole is formed in the surface of the adjusting disc, a plurality of second phase positioning holes which are arranged at intervals are formed in the circumferential direction of the balance disc, each second phase positioning hole corresponds to the phase of the piston of each cylinder, and when the first phase positioning hole is in butt joint with the second phase positioning hole corresponding to the piston of the cylinder to be detected, the phase of the induction block is the same as the phase of the piston of the cylinder to be detected.
2. A Stirling engine cylinder pressure detecting system according to claim 1, wherein the rotation angle sensor is a photoelectric encoder, the photoelectric encoder is fixed to an end cover of the crankcase and located on one side of the rotary plate, a rotary rod is fixed to one side of the rotary plate close to the photoelectric encoder, the rotary rod is connected to a rotor of the photoelectric encoder, and the rotary rod can drive the rotor of the photoelectric encoder to rotate when rotating.
3. A stirling engine cylinder pressure sensing system according to claim 1, wherein the balance plate is provided with a balance notch in a circumferential direction thereof for balancing rotation of the rotary plate.
4. A Stirling engine cylinder pressure detecting system according to claim 1, wherein a positioning protrusion is fixed to one surface of the adjusting plate close to the balance plate, a positioning groove matched with the positioning protrusion is formed in one surface of the balance plate close to the adjusting plate, and the positioning protrusion is rotatably connected into the positioning groove.
5. A method for detecting the cylinder pressure of a Stirling engine, which is performed by the system for detecting the cylinder pressure of a Stirling engine according to any one of claims 1 to 4, comprising the steps of:
s100: switching the connecting piece into a plugging piece to enable each cylinder of the Stirling engine to operate in a plugging state;
s200: acquiring the pressure of a hot cavity in the cylinder to be detected through the pressure detection unit, and acquiring the rotation angle of the crankshaft corresponding to the cylinder to be detected through the crankshaft rotation angle measurement unit to obtain a crankshaft phase value of a dynamic top dead center corresponding to the maximum hot cavity pressure of the cylinder to be detected;
s300: switching the connecting piece into a communicating piece to enable each cylinder of the Stirling engine to operate in a normal state;
s400: acquiring the pressure of a hot cavity in the cylinder to be detected through the pressure detection unit, and acquiring the rotation angle of the crankshaft corresponding to the cylinder to be detected through the crankshaft rotation angle measurement unit so as to obtain hot cavity pressure values of the cylinder to be detected corresponding to each phase of the crankshaft when the cylinder to be detected works normally;
s500: and taking the crankshaft phase value of the dynamic top dead center as a base point to obtain an indicator diagram of the relation between the pressure of the hot cavity of the measured cylinder and the crank angle.
6. A method for detecting the cylinder pressure of a Stirling engine according to claim 5, wherein in step S400, the proximity sensor senses a sensing block while the rotary plate is rotating, so as to obtain a crank phase value corresponding to the maximum pressure of each cylinder when the cylinder to be detected is in normal operation.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210421269.1A CN114526916B (en) | 2022-04-21 | 2022-04-21 | Stirling engine cylinder pressure detection system and detection method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210421269.1A CN114526916B (en) | 2022-04-21 | 2022-04-21 | Stirling engine cylinder pressure detection system and detection method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114526916A CN114526916A (en) | 2022-05-24 |
| CN114526916B true CN114526916B (en) | 2022-07-26 |
Family
ID=81627951
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210421269.1A Active CN114526916B (en) | 2022-04-21 | 2022-04-21 | Stirling engine cylinder pressure detection system and detection method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114526916B (en) |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4111041A (en) * | 1977-09-29 | 1978-09-05 | The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration | Indicated mean-effective pressure instrument |
| US4253303A (en) * | 1979-10-01 | 1981-03-03 | Liljequist Jon L | Engines, and particularly those incorporating the Stirling cycle |
| US5219398A (en) * | 1990-08-10 | 1993-06-15 | Yamaha Hatsudoki Kabushiki Kaisha | Control device for internal combustion engine |
| CN101738211B (en) * | 2008-11-21 | 2013-01-02 | 比亚迪股份有限公司 | Device and method for measuring rotation angle of engine crankshaft |
| JP2013024236A (en) * | 2011-10-14 | 2013-02-04 | Akira Watanabe | Stirling engine |
| US9435277B2 (en) * | 2014-07-29 | 2016-09-06 | Freescale Semiconductor, Inc. | Method of calibrating a crank angle of a combustion engine |
| CN104314688B (en) * | 2014-08-13 | 2016-10-05 | 吉林大学 | A kind of device and method judging engine crankshaft rotation phase place and real time position |
-
2022
- 2022-04-21 CN CN202210421269.1A patent/CN114526916B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN114526916A (en) | 2022-05-24 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA1222317A (en) | Method of determining engine cylinder compression pressure and power output | |
| Varbanets et al. | Improvement of diagnosing methods of the diesel engine functioning under operating conditions | |
| CA2132160A1 (en) | Methods and apparatus for testing engines | |
| JP2016183671A (en) | Systems and methods for locating engine event | |
| KR20160082676A (en) | System and method for regulating exhaust gas recirculation in an engine | |
| US20170175661A1 (en) | Real time detection and diagnosis of change in peak firing pressure | |
| US20160312716A1 (en) | Knock sensor systems and methods for detection of component conditions | |
| BR102016002606B1 (en) | DIAGNOSIS METHOD AND SYSTEM OF A DETONATION SENSOR AND NON-TRANSITORY COMPUTER-READable MEDIUM | |
| Mohammed et al. | Performance and combustion characteristics of a novel crank-rocker engine | |
| CN114526916B (en) | Stirling engine cylinder pressure detection system and detection method thereof | |
| WO2017011206A1 (en) | Panoramic knock sensor systems and methods for engine component health detection | |
| Vorraro et al. | Testing of a Modern Wankel Rotary Engine-Part II: Motoring Analysis | |
| RU2454643C1 (en) | Method of defining ice power losses | |
| CN114510825B (en) | Method and system for obtaining optimal phase difference of opposed piston engine | |
| US20200332733A1 (en) | System and method for estimating engine performance | |
| JP7266545B2 (en) | fuel injection controller | |
| JP2001082238A (en) | Method for deciding top dead center phase of reciprocating compression engine | |
| KR20210005823A (en) | Misfiring cylinder detection method and device for reciprocating internal combustion engine using torsional vibration signal | |
| EP3344969B1 (en) | Method for operating a piston engine and arrangement for detecting failure of a head gasket | |
| JPH0259941B2 (en) | ||
| RU2785419C1 (en) | Method for estimating the power of mechanical losses of an internal combustion engine | |
| Antonopoulos et al. | Identification and correction of the error induced by the sampling method used to monitor cylinder pressure of reciprocating internal combustion engines | |
| RU93007772A (en) | METHOD OF DIAGNOSTICS OF INTERNAL COMBUSTION ENGINES | |
| RU2003119976A (en) | METHOD FOR DIAGNOSTIC OF INTERNAL COMBUSTION ENGINE | |
| JPH0259940B2 (en) |
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 | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |