Integrated air-cooled small organic rankine cycle waste heat power generation system

Abstract

This invention discloses an integrated, air-cooled, small-scale organic Rankine cycle (ORC) waste heat power generation system, belonging to the technical field of ORC waste heat recovery equipment. The system includes a frame and a heat exchanger, ORC expander, generator, condenser, cooling fan, and cam-piston pump assembly mounted on it. High-temperature waste heat hot water is introduced into the chamber through a hot water inlet pipe to heat and vaporize the liquid working fluid; the high-pressure gaseous working fluid enters the ORC expander with dual inlets and symmetrical air intake to perform work, driving the impeller to rotate and coaxially drive the generator to generate electricity; after performing work, the low-pressure working fluid is liquefied through an air-cooled finned tube condenser and pressurized by the cam-piston pump before being sent back to the heat exchanger to complete a closed-loop cycle. This invention features a compact structure suitable for vehicle mounting, an improved heat transfer efficiency for low-temperature heat sources in the heat exchange chamber, air-cooled cooling eliminating the need for an external water source, direct-drive expansion eliminating transmission losses, and a cam-piston pump for gas-electric co-pressurization to reduce energy consumption. It is suitable for various waste heat power generation scenarios with low-temperature heat sources of 80~130℃.

Description

Technical Field

[0001] This invention belongs to the technical field of low-temperature waste heat recovery power generation equipment, and specifically relates to an integrated air-cooled small organic Rankine cycle waste heat power generation system. Background Technology

[0002] Currently, the Organic Rankine Cycle (ORC) technology utilizes low-boiling-point organic working fluids to convert low-grade heat energy into electrical energy, showing great promise in fields such as industrial waste heat recovery and geothermal power generation. However, existing small-scale ORC power generation equipment still suffers from the following technical shortcomings:

[0003] First, the system is modular and bulky. Components such as the evaporator, expander, and condenser are installed independently and connected by long pipelines. This not only takes up a lot of space but also results in many exposed joints and a high risk of refrigerant leakage, making it unsuitable for installation in compact environments such as vehicles.

[0004] Second, condensation relies on water cooling, limiting its applicability. Most systems use water-cooled condensers, requiring a cooling tower and circulating water pump, making them unable to operate independently in outdoor, mobile, or water-scarce conditions. Although some solutions attempt air cooling, the overall integration is low, and the structure remains bulky.

[0005] Third, the heat exchanger efficiency is insufficient. Conventional straight tube or coil heat exchangers have low heat transfer efficiency in low-temperature hot water (80~130℃) conditions. Although plate heat exchangers have higher efficiency, their flow channels are narrow and easily blocked, making them unsuitable for industrial hot water containing impurities or vehicle environments with high vibration.

[0006] Fourth, there is intermediate transmission loss between the expander and the generator. Traditional solutions use transmission mechanisms such as gearboxes and belts, which increases mechanical losses, as well as the overall size of the machine and the difficulty of maintenance.

[0007] Fifth, low-boiling-point organic working fluids (such as R245fa) have strong permeability. In the long-term operation of a large number of flanges and pipe joints in a split system, leakage is likely to occur, resulting in decreased efficiency and increased operation and maintenance costs.

[0008] In addition, existing systems mostly use fixed-frequency driven working fluid pumps, which cannot automatically adjust the working fluid circulation volume when the heat source temperature fluctuates, resulting in poor work stability of the expander.

[0009] Therefore, in view of the shortcomings of the above solutions in actual manufacturing and implementation, an integrated air-cooled small organic Rankine cycle waste heat power generation system with compact structure, self-cooling, high heat exchange efficiency, reliable sealing and adaptive adjustment is provided to solve the above technical problems. Summary of the Invention

[0010] This invention proposes an integrated air-cooled small-scale organic Rankine cycle waste heat power generation system, which solves the problems in the prior art.

[0011] The technical solution of this invention is implemented as follows: An integrated air-cooled small organic Rankine cycle waste heat power generation system includes a frame and the following components mounted on the frame:

[0012] A heat exchanger filled with an organic working fluid, the heat exchanger having a heat exchange chamber, and the heat exchanger being connected to a hot water inlet pipe and a hot water outlet pipe;

[0013] ORC expanders are used to convert the thermal energy of high-pressure gaseous organic working fluids into mechanical torque output.

[0014] The generator, coaxially and directly connected to the ORC expander, is used to convert mechanical torque into electrical energy output;

[0015] A condenser is used to cool and liquefy the low-pressure gaseous working fluid after it has expanded and done work.

[0016] A cooling fan is installed on the outside of the condenser for forced air cooling.

[0017] A cam-piston pump assembly is used to pressurize and deliver liquid organic working fluid back to the heat exchanger;

[0018] The heat exchanger, ORC expander, condenser, and cam piston pump assembly are sequentially connected through internal pipelines to form a closed-loop circulation circuit.

[0019] The rack integrates a heat exchanger, expander, generator, condenser, fan, and cam pump to form a compact closed-loop circulation system, which is convenient for vehicle installation.

[0020] In a preferred embodiment, the heat exchanger is provided with a working fluid outlet pipe at the top, which is connected to the ORC expander, and a working fluid inlet pipe at the bottom, which is connected to the cam piston pump assembly.

[0021] The heat exchanger has a working fluid outlet at the top and a working fluid inlet at the bottom, which enables the orderly circulation of the working fluid and ensures sufficient and efficient heat exchange.

[0022] In a preferred embodiment, the heat exchange cavity has an elliptical cross-section. Or round The hot water inlet pipe and the hot water outlet pipe are respectively located on both sides of the heat exchange chamber.

[0023] The heat exchanger can also be a multi-tube heat exchanger.

[0024] oval, The design uses a circular or multi-tube structure to maximize the heat exchange area of ​​the heat exchange chamber within the same volume. The water inlet and outlet on both sides extend the hot water travel distance, effectively improving the heat transfer efficiency of the low-temperature heat source.

[0025] In a preferred embodiment, the ORC expander includes a housing with an inner cavity. A first inlet pipe and a second inlet pipe are respectively provided on opposite sides of the housing. An outlet end is provided on the side of the housing. An impeller is rotatably mounted inside the inner cavity. The first inlet pipe and the second inlet pipe are arranged opposite to each other. The working fluid entering the inner cavity through the first inlet pipe and the second inlet pipe converges in the inner cavity to form an annular tapered guide channel. The working fluid, accelerated by the annular tapered guide channel, impacts the impeller to do work. The working fluid after doing work is discharged through the outlet.

[0026] The dual inlet symmetrical air intakes converge in the inner cavity of the casing to form an annular tapering flow channel, which makes the impeller uniformly stressed circumferentially and stably provides mechanical force output.

[0027] In a preferred embodiment, the impeller includes a main shaft that is drivenly connected to a generator; the working fluid outlet pipe of the heat exchanger is connected to the first inlet pipe of the ORC expander; the working fluid outlet pipe of the heat exchanger is connected to a cam piston pump assembly; and the outlet of the ORC expander is connected to a condenser.

[0028] The main shaft is directly connected to the generator to eliminate gear and belt drive losses, and the pipeline connects the heat exchanger, expander, and condenser to form a complete circulation loop.

[0029] In a preferred embodiment, the cam piston pump assembly includes a drive motor, with a bracket fixedly mounted at one end of the drive motor. A cylinder is mounted on the bracket, and a first inlet pipe and a first outlet pipe are provided at one end of the cylinder. The bracket includes a base plate, and the base plate and the cylinder form a closed space. A second inlet pipe and a second outlet pipe are provided on the base plate. A cam piston is movably mounted inside the cylinder, and the cam piston divides the cylinder into cavity A and cavity B. The first inlet pipe and the first outlet pipe are connected to cavity A, and the second inlet pipe and the second outlet pipe are connected to cavity B. The cam piston is driven by the drive motor.

[0030] The cam piston divides the cylinder into two independent chambers, A and B. The combined pneumatic and electric booster effectively reduces the motor's compression load and lowers power consumption.

[0031] In a preferred embodiment, the first inlet pipe and the first outlet pipe are connected by a first side pipe, the second inlet pipe and the second outlet pipe are connected by a second side pipe, the first branch pipe is connected to the bottom of the condenser, and the second branch pipe is connected to the working fluid inlet pipe.

[0032] The two side pipes are connected to allow the working medium to enter and exit the A and B chambers in an orderly manner, ensuring continuous pressurized delivery and preventing backflow and contamination of the medium.

[0033] In a preferred embodiment, the condenser is an air-cooled finned tube condenser, and the cooling fan and the condenser form an integrated air-cooled heat dissipation module.

[0034] The air-cooled finned tube condenser, combined with a cooling fan, provides forced convection cooling, eliminating the need for an external cooling tower and offering strong adaptability.

[0035] In a preferred embodiment, the organic working fluid is R245fa, a low-boiling-point working fluid.

[0036] The R245fa low-boiling-point working fluid phase change temperature is matched with a low-temperature heat source of 80~130℃, which improves the net output efficiency of medium and low temperature waste heat power generation.

[0037] In a preferred embodiment, a pressure sensor is installed on the pipeline between the heat exchanger and the ORC expander, and the pressure sensor signal is used for closed-loop regulation of the working fluid discharge pressure of the cam piston pump.

[0038] A pressure sensor is installed to collect the working fluid evaporation pressure signal in real time. The controller compares the measured pressure with the preset target pressure and adjusts the discharge pressure of the cam piston pump according to the deviation in a closed loop. Specifically, it adjusts the motor speed and pneumatic auxiliary pressure to stabilize the evaporation pressure near the target value, ensuring stable operation of the expander.

[0039] The beneficial effects of this invention after adopting the above technical solution are as follows: This invention integrates a heat exchanger, ORC expander, generator, air-cooled condenser, and cam piston pump assembly into a compact closed-loop circulation system. The elliptical heat exchange chamber improves heat transfer efficiency, the dual-inlet symmetrical intake expander operates smoothly, the direct drive of the main shaft eliminates transmission losses, the cam piston pump provides gas-electric synergistic pressurization to reduce energy consumption, air cooling eliminates the need for a water source, and closed-loop pressure control ensures stable operation. Overall, it is adaptable to various waste heat scenarios. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0042] Figure 2 This is a schematic diagram of the overall structure of the present invention;

[0043] Figure 3 This is a schematic cross-sectional view of the heat exchanger of the present invention;

[0044] Figure 4 This is a schematic diagram of the overall structure of the ORC expander of the present invention;

[0045] Figure 5 This is a schematic diagram of the overall structure of the ORC expander of the present invention;

[0046] Figure 6 for Figure 5 Schematic diagram of the AA structure;

[0047] Figure 7 This is a schematic diagram of the outer shell structure of the ORC expander;

[0048] Figure 8 This is a schematic diagram of the ORC expander impeller structure.

[0049] Figure 9 This is a schematic diagram of the overall structure of the cam piston pump assembly;

[0050] Figure 10 This is a schematic diagram of a portion of the cam piston pump assembly.

[0051] Figure 11 A cross-sectional schematic diagram of a portion of the cam piston pump assembly;

[0052] Figure 12 This is a schematic diagram of a portion of the cam piston pump assembly.

[0053] Figure 13 This is a schematic diagram of a multi-tube heat exchanger.

[0054] In the diagram, 1. Cam piston pump assembly; 11. Drive motor; 12. Bracket; 121. Second inlet pipe; 122. Second outlet pipe; 123. Second bearing housing; 124. Base plate; 13. Cylinder; 131. Chamber A; 132. Chamber B; 133. Guide column; 14. End cap; 141. First inlet pipe; 142. First outlet pipe; 143. First bearing housing; 15. Coupling; 16. Spline sleeve; 17. Cam piston; 171. Guide groove; 18. Glyd ring; 19. Spline rod; 2. First side pipe; 21. First branch pipe; 3. Condenser; 4. 5. High-pressure hose; 6. ORC expander; 7. Outer shell; 8. First inlet pipe; 9. Second inlet pipe; 10. Cover plate; 11. Outlet end; 12. Impeller; 13. Main shaft; 14. Blade; 15. Turntable; 16. Boss; 17. Guide vane; 18. Snap ring; 19. Sealing ring; 20. Fixed cylinder; 21. Generator; 22. Heat exchanger; 23. Heat exchange chamber; 24. Hot water outlet pipe; 35. Hot water inlet pipe; 46. Working fluid inlet pipe; 57. Working fluid outlet pipe; 88. Second side pipe; 9. Second branch pipe; 10. Cooling fan. Detailed Implementation

[0055] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0056] like Figure 1 , Figure 2 As shown, an integrated air-cooled small organic Rankine cycle waste heat power generation system includes a frame and the following components mounted on the frame:

[0057] The heat exchanger 7 is filled with an organic working fluid. The heat exchanger 7 is provided with a heat exchange chamber 71. The heat exchanger 7 is connected to a hot water inlet pipe 73 and a hot water outlet pipe 72.

[0058] ORC expander 5 is used to convert the thermal energy of high-pressure gaseous organic working fluid into mechanical torque output.

[0059] Generator 6, coaxially and directly connected to ORC expander 5, is used to convert mechanical torque into electrical energy output;

[0060] Condenser 3 is used to cool and liquefy the low-pressure gaseous working fluid after it expands and does work.

[0061] A cooling fan is installed on the outside of condenser 3 for forced air cooling.

[0062] Cam piston pump assembly 1, used to pressurize and transport liquid organic working fluid back to heat exchanger 7;

[0063] The heat exchanger 7, ORC expander 5, condenser 3, and cam piston pump assembly 1 are connected in sequence through internal pipelines to form a closed-loop circulation circuit.

[0064] like Figure 3 As shown, the heat exchanger 7 has a working fluid outlet pipe at the top, which is connected to the ORC expander 5, and a working fluid inlet pipe 74 at the bottom, which is connected to the cam piston pump assembly 1.

[0065] In this embodiment, the heat exchange cavity 71 has an elliptical cross-section. Or round Hot water inlet pipe 73 and hot water outlet pipe 72 are respectively installed on both sides of heat exchange chamber 71.

[0066] The heat exchanger can also be a multi-tube heat exchanger, such as Figure 13 As shown.

[0067] Elliptical, circular, or multi-tube structures are used to maximize the heat exchange area of ​​the heat exchange chamber under the same volume conditions. Water inlets and outlets on both sides extend the hot water travel distance and effectively improve the heat transfer efficiency of low-temperature heat sources.

[0068] like Figures 4 to 8 As shown, the ORC expander 5 includes a housing 51 with an inner cavity. A first inlet pipe 511 and a second inlet pipe 512 are respectively provided on opposite sides of the housing. An outlet end 521 is provided on the side of the housing. An impeller 53 is rotatably installed inside the inner cavity. The first inlet pipe 511 and the second inlet pipe 512 are arranged opposite to each other. The working fluid entering the inner cavity through the first inlet pipe 511 and the second inlet pipe 512 merges in the inner cavity to form an annular tapered guide channel. The working fluid accelerated by the annular tapered guide channel impacts the impeller 53 to do work. The working fluid after doing work is discharged through the outlet end 521.

[0069] Specifically, the first inlet pipe 511 and the second inlet pipe 512 are equipped with high-pressure hoses 4, through which organic working fluid is injected into the inner cavity.

[0070] In this embodiment, the outer shell 51 and the cover plate 52 are used. The outer shell 51 is a one-piece cast cavity with no seams. The outer shell 51 has a first inlet pipe 511 and a second inlet pipe 512 for connecting the high-pressure gaseous R245fa working fluid from the heat exchanger 7.

[0071] The first inlet pipe 511 and the second inlet pipe 512 are respectively inclined, and the angle between the first inlet pipe 511, the second inlet pipe 512 and the horizontal line is 10 degrees to 20 degrees. In this embodiment, it is 15 degrees.

[0072] The cover plate 52 is fixedly connected to the outer shell 51, and the space between the cover plate 52 and the outer shell 51 forms an inner cavity. The cover plate 52 is provided with a channel, and the end of the channel away from the outer shell 51 forms an outlet end 521. The cross-section of the outlet end 521 is rectangular.

[0073] The impeller 53 includes a turntable 533, on which multiple blades 532 are provided. The multiple blades 532 are evenly distributed along the circumference of the turntable 533, and a working fluid flow channel is formed between adjacent blades 532.

[0074] An annular tapering guide channel is formed inside the casing. The cross-sectional area of ​​this channel gradually decreases along the flow direction of the working fluid, and the outlet of the channel faces the inlet direction of the outer peripheral blade 532 of the impeller 53. After the high-pressure gaseous working fluid enters from the first inlet pipe 511 and the second inlet pipe 512 of the ORC working fluid, it is accelerated by the annular tapering guide channel and evenly distributed along the circumference of the impeller 53, impacting the outer peripheral blade 532 of the impeller 53 at the designed angle.

[0075] A boss 534 is provided at the center of the turntable 533, and multiple guide vanes 535 are provided on the boss 534. The multiple guide vanes 535 are evenly distributed along the circumference of the boss 534.

[0076] The impeller 53 is fixedly connected to the main shaft 531, which extends outward through the housing; a fixed cylinder is fixedly installed on the side of the housing 51, through which the main shaft 531 passes and extends out of the housing.

[0077] The impeller 53 is located at the center of the flow channel inside the casing and adopts a radial turbine blade 532 structure. Several curved blades 532 are evenly distributed around the outer circumference of the impeller 53. The profile of each blade 532 is optimized based on the flow velocity field of the R245fa gaseous working fluid under design conditions. During operation, the high-pressure working fluid flows radially inward from the outer circumference of the impeller 53, driving the blades 532 to rotate, which in turn drives the impeller 53 and the main shaft 531 fixed at the center of the impeller 53 to rotate, outputting mechanical torque. The main shaft 531 of the impeller 53 extends outward through a bearing, and has a power output interface at its end for connecting an external generator 6.

[0078] A fixing cylinder 56 is provided on the side wall of the outer casing, and a bearing is installed on the main shaft 531. The bearing is located between the inner wall of the fixing cylinder 56 and the outer wall of the main shaft 531.

[0079] The spindle 531 is fitted with a sealing ring 55, which is located at the end of the spindle 531 near the inner cavity.

[0080] One end of the outer casing 51 is open, allowing the impeller 53, bearing, and sealing ring 55 to be installed along the main shaft 531. The bearing is axially fixed by a snap ring 54, and the open end is sealed to the cover plate 52. The overall cavity volume of the casing is determined according to the design expansion ratio of the R245fa working fluid.

[0081] The bearing is sleeved on the outside of the main shaft 531 and installed between the central bearing seat of the housing and the central mating hole of the outlet cover plate 52, providing rotational support for the main shaft 531 and ensuring that the impeller 53 remains aligned during high-speed rotation. An annular sealing ring is installed between the bearing and the mating surfaces of the housing and the outlet cover plate 52. This sealing ring performs two sealing functions simultaneously: one between the flange face of the open end of the housing and the flange face of the outlet cover plate 52, preventing leakage of the working medium along the flange gap; and the other between the rotational fit gap between the central hole of the outlet cover plate 52 and the main shaft 531, preventing leakage of the working medium along the main shaft 531. Both seals are achieved simultaneously by the same sealing ring with a specific cross-sectional structure, forming a double sealing barrier.

[0082] In this embodiment, the cover plate 52 seals the open end of the outer casing 51 and is fastened to the outer casing 51 with bolts. A working fluid outlet is opened in the middle of the cover plate 52, through which the low-pressure gaseous working fluid, after expansion and work, is discharged and sent to the condenser 3 via an external pipeline. A sealing ring is pressed between the inner end face of the cover plate 52 and the surface of the outer casing 51, while a dynamic seal is achieved between the inner wall of the central hole of the cover plate 52 and the outer wall of the main shaft 531 by an extended sealing lip of the same sealing ring. The cover plate 52 and the outer casing 51 are detachably connected; after removing the cover plate 52, the impeller 53, bearing, and sealing ring can be removed sequentially along the axial direction.

[0083] The ORC expander 5 includes a casing and operates on the following principle: High-pressure gaseous R245fa organic working fluid enters the annular tapering guide channel of the casing through the first inlet pipe 511 and the second inlet pipe 512. After being accelerated within the tapering channel, it is evenly distributed circumferentially along the impeller 53 and injected into the radial blades 532 of the impeller 53 at a designed impact angle. The kinetic and internal energy of the working fluid acts on the curved surface of the blades 532, generating a circumferential driving torque, which drives the impeller 53 and the main shaft 531 to rotate at high speed, converting the thermal energy of the working fluid into the mechanical torque output by the main shaft 531.

[0084] During the work process, the temperature and pressure of the working fluid decrease significantly, turning into a low-pressure gaseous working fluid. It flows through the central region of the impeller 53 to the outlet of the cover plate 52 and is discharged to the external condenser 3.

[0085] Specifically, the main shaft 531 is connected to the generator 6 via a drive, the working fluid outlet pipe 75 of the heat exchanger 7 is connected to the first inlet pipe 511 of the ORC expander 5, the working fluid outlet pipe 75 of the heat exchanger 7 is connected to the cam piston pump assembly 1, and the outlet of the ORC expander 5 is connected to the condenser 3.

[0086] like Figures 9 to 12 As shown, the cam piston pump assembly 1 includes a drive motor 11, with a bracket 12 fixedly mounted at one end of the drive motor 11. A cylinder 13 is mounted on the bracket 12, and a first inlet pipe 141 and a first outlet pipe 142 are provided at one end of the cylinder 13. The bracket 12 includes a base plate 124, which forms a closed space with the cylinder 13. A second inlet pipe 121 and a second outlet pipe 142 are provided on the base plate 124. A cam piston 17 is movably mounted inside the cylinder 13, dividing the cylinder 13 into a cavity A 131 and a cavity B 132. The first inlet pipe 141 and the first outlet pipe 142 are connected to cavity A 131, and the second inlet pipe 121 and the second outlet pipe 122 are connected to cavity B 132. The cam piston 17 is connected to the drive motor 11 for transmission.

[0087] The first inlet pipe 141 and the first outlet pipe 142 are connected by the first side pipe 2, the second inlet pipe 121 and the second outlet pipe 122 are connected by the second side pipe 8, the first branch pipe 21 is connected to the bottom of the condenser 3, and the second branch pipe 122 is connected to the working fluid inlet pipe 74.

[0088] The cam sidewall is provided with a guide groove 171, and the inner wall of the cylinder 13 is provided with a guide post 133. The guide post 133 is located in the guide groove 171, and the cam piston 17 reciprocates along the cylinder 13 through the guide groove 171.

[0089] A ball spline transmission assembly is slidably installed inside the cylinder 13, and the ball spline transmission assembly is connected to the drive motor 11 for transmission.

[0090] The ball spline transmission assembly includes a spline rod 19 and a spline sleeve 16. The spline sleeve 16 is mounted on the spline rod 19, and the spline rod 19 is connected to the drive motor 11. The spline sleeve 16 is fitted together with the end of the cam piston 17.

[0091] The drive motor 11 includes a motor shaft, which passes through the base plate 124 and is connected to the spline rod 19.

[0092] Specifically, the drive motor 11 includes a motor shaft, and a coupling 15 is installed between the spline rod 19 and the motor shaft.

[0093] The cylinder 13 includes an end cap 14, which is fixedly connected to the cylinder 13. The first inlet pipe 141 and the first outlet pipe 142 are located on the end cap 14. In this embodiment, the first inlet pipe 141 and the first outlet pipe 142 are integrally formed.

[0094] The end cap 14 is provided with a first bearing seat 143, and the bracket 12 is provided with a second bearing seat 123. The first bearing seat 143 and the second bearing seat 123 are respectively equipped with bearings, and the spline rod 19 passes through the two bearings.

[0095] The side wall of the cam piston 17 is provided with at least one annular sealing groove, and a Gladley ring 18 is installed in the sealing groove.

[0096] Specifically, the annular sealing groove is located on the side wall of the cam piston 17 near the end cap 14.

[0097] The working process of this cam piston assembly 1 is as follows:

[0098] Low-pressure liquid organic working fluid enters chamber A 131 from condenser 3 through the first inlet pipe 131 of end cover 14. Drive motor 11 drives splined rod 19 to rotate via coupling 15. Splined sleeve 16 slides along splined rod 19 and pushes cam piston 17 to reciprocate. When cam piston 17 moves towards end cover 14, the volume of chamber A 131 decreases, the working fluid is compressed and pressurized, and the high-pressure working fluid is discharged to the heat exchanger through the first outlet pipe 142. When cam piston 17 retracts towards bottom plate 124, the volume of chamber A 131 increases, and low-pressure working fluid is re-drawn in through the first inlet pipe 141.

[0099] One-way valves are installed at the positions of the first inlet pipe 141 and the first outlet pipe 142. When the cam piston 17 moves away from the end cover 14, the volume of cavity A 131 increases and a negative pressure is formed. The one-way valve at the first inlet pipe 141 opens under the action of the pressure difference, and the low-pressure liquid working fluid is drawn into cavity A 131.

[0100] During the pressurization stage, high-pressure gas is injected: After the first-stage mechanical compression is completed, the cam piston 17 is at the end away from the end cover 14. At this time, the pressure of the external high-pressure auxiliary gas source is higher than the pressure of the compressed working medium in the A cavity 131. After the high-pressure gas is depressurized by the proportional pressure regulating valve, it is injected into the A cavity 131 through the same first inlet pipe 141 to perform secondary pressurization on the working medium.

[0101] High-pressure auxiliary gas is introduced into chamber B 132 through the second inlet pipe 121 of the base plate 124. This gas assists in pushing the piston when the cam piston 17 retracts, sharing the motor load. The second outlet pipe 122 is used to discharge the gas from chamber B 132. Two sets of bearings provide end support for the splined rod 19, ensuring the stability of the reciprocating motion. The Gladley ring 18 on the side wall of the cam piston 17 completely isolates chamber A 131 from chamber B 132, preventing cross-contamination between the working fluid and the auxiliary gas.

[0102] In the combined pneumatic-electric supercharging mode, the external aerodynamic thrust and the mechanical driving force of the motor work together, and the motor only needs to undertake part of the compression work, which greatly reduces power consumption.

[0103] Specific actions involved in the process of introducing organic working fluid:

[0104] Increased volume generates negative pressure: The cam piston 17 moves away from the end cover, the volume of cavity A 131 gradually increases, and the pressure inside the cavity decreases.

[0105] One-way valve opening: When the pressure inside chamber A 131 is lower than the outlet pressure of condenser 3, the one-way valve at the first inlet pipe 141 automatically opens under the action of pressure difference.

[0106] Working fluid intake: The working fluid is drawn into the working fluid chamber 131 through the first inlet pipe 141 on the front end cover 14.

[0107] Filling complete: When the cam piston continues to move away from the end cap 14 to the end, the volume of cavity A 131 reaches its maximum and the cavity is completely filled with low-pressure liquid working fluid.

[0108] Auxiliary action: High-pressure gas is introduced into chamber B 132, pushing the cam piston 17 to retract towards the end cover 14, accelerating the intake of gas and ensuring that the piston is fully returned to its original position.

[0109] In this embodiment, the condenser 3 is an air-cooled finned tube condenser, and the cooling fan 9 and the condenser 3 form an integrated air-cooled heat dissipation module.

[0110] In this embodiment, the organic working fluid is R245fa, a low-boiling-point working fluid.

[0111] A pressure sensor is installed on the pipeline between the heat exchanger 7 and the ORC expander 5. The pressure sensor signal is used to regulate the working fluid discharge pressure of the cam piston 17 pump in a closed loop.

[0112] The entire waste heat power generation system operates as follows:

[0113] The working process of this system is the coordinated operation of a closed thermodynamic cycle on the working fluid side and a water cycle on the heat source side, which includes four consecutive stages: 1. Constant pressure heat absorption and vaporization in heat exchanger 7; 2. Adiabatic expansion and work in ORC expander 5; 3. Constant pressure condensation and heat release in condenser 3; 4. Adiabatic compression and pressurization by cam piston 17 pump.

[0114] The four stages repeat in a cycle, forming a complete thermodynamic cycle that continuously converts the low-temperature waste heat of 80~130℃ into electrical energy.

[0115] I. Water circulation on the heat source side

[0116] High-temperature waste heat hot water enters the elliptical heat exchange cavity 71 of the heat exchanger 7 through the hot water inlet pipe 73. The hot water flows within the elliptical heat exchange cavity 71, whose cross-section is elliptical or circular. The heat exchanger can also be a multi-tube type, designed to maximize the heat exchange area within the same volume, increasing the contact area between the hot water and the cavity wall and improving heat exchange efficiency. The hot water transfers heat through the cavity wall to the liquid R245fa organic working fluid inside the cavity. The working fluid absorbs heat and heats up, while the hot water releases heat and cools down before being discharged through the hot water outlet pipe 72, returning to the external hot water circuit.

[0117] II. Working fluid thermodynamic cycle

[0118] The heat exchanger 7 is filled with liquid R245fa working fluid. When high-temperature hot water flows through the elliptical heat exchange cavity 71, the increased heat exchange area enhances heat transfer efficiency, efficiently transferring heat to the liquid R245fa. After absorbing the latent heat of vaporization, the working fluid's temperature and pressure rise, transforming it into a high-pressure superheated gaseous working fluid. The vaporized high-pressure gaseous working fluid then enters the ORC expander 5 through a pipeline from the top outlet of the heat exchanger 7.

[0119] III. Work done by adiabatic expansion

[0120] High-pressure gaseous R245fa enters the working fluid inlet of the ORC expander 5 from the top outlet of heat exchanger 7 through a pipeline. The working fluid first enters the annular tapering guide channel inside the shell—the cross-sectional area of ​​the channel gradually decreases along the flow direction, and the working fluid is accelerated in the tapering channel.

[0121] The accelerated working fluid is uniformly injected circumferentially from the outer periphery of the impeller 53 into the curved surface of the blades 532 of the centripetal turbine impeller 53. The kinetic energy and internal energy of the working fluid act on the curved surface of the blades 532, generating a circumferential driving torque, which drives the impeller 53 and the main shaft 531 to rotate at high speed.

[0122] The impeller 53's main shaft 531 is coaxially and directly connected to the generator 6's rotor. The mechanical torque of the impeller 53's rotation directly drives the generator 6's rotor to rotate, converting mechanical energy into AC electrical energy output.

[0123] After the work is done, the temperature and pressure of the working fluid decrease significantly, and it becomes a low-pressure gaseous working fluid. It flows from the central region of the impeller 53 through the working fluid discharge port 521 of the outlet cover plate 52 into the condenser 3.

[0124] IV. Constant Pressure Condensation and Heat Release

[0125] After the work is done, the low-pressure gaseous R245fa enters the condenser 3 from the expander outlet through internal piping. The condenser 3 is an air-cooled finned tube structure—the working fluid flows inside the finned tubes, and dense metal fins are installed on the outside of the tubes to increase the heat dissipation area.

[0126] The cooling fan installed on the outside of condenser 3 operates continuously, forcibly drawing ambient air through the finned tube bundle of condenser 3. As the ambient air flows through the finned tubes, it carries away the latent heat of the working fluid and releases it into the surrounding atmosphere.

[0127] As the working fluid flows inside the pipe, it continuously releases heat, and its temperature gradually decreases to the saturation temperature. It then undergoes a phase change and liquefies into a low-temperature liquid working fluid, which collects in the liquid collection area at the bottom of condenser 3.

[0128] The entire unit adopts an air-cooled heat dissipation solution, eliminating the need for external cooling towers, circulating water pumps, and water replenishment devices. It can operate independently in outdoor, mobile, and water-scarce environments. The cooling fan speed can be closed-loop adjusted according to the ambient temperature and the working fluid temperature at the condenser outlet 3, ensuring sufficient liquefaction of the working fluid under different environmental conditions.

[0129] V. Adiabatic Compression Pressurization

[0130] The liquid R245fa at the bottom of the condenser 3 is drawn in by the cam piston 17 pump, pressurized and then sent back to the heat exchanger 7 to complete the closed-loop circulation of the working fluid.

[0131] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An integrated, air-cooled, small-scale organic Rankine cycle waste heat power generation system, characterized in that, Includes the following components for fixed installation: The heat exchanger (7) is filled with organic working fluid. The heat exchanger (7) is provided with a heat exchange cavity (71). The heat exchanger (7) is connected to a hot water inlet pipe (73) and a hot water outlet pipe (72). ORC expander (5) is used to convert the thermal energy of high-pressure gaseous organic working fluid into mechanical torque output; The generator (6) is coaxially and directly connected to the ORC expander (5) to convert mechanical torque into electrical energy output; The condenser (3) is used to cool and liquefy the low-pressure gaseous working fluid after it expands and does work. A cooling fan is installed on the outside of the condenser (3) for forced air cooling. Cam piston (17) pump assembly (1) for pressurizing and delivering liquid organic working fluid back to the heat exchanger (7); The heat exchanger (7), ORC expander (5), condenser (3), cam piston (17) and pump assembly (1) are connected in sequence through internal pipelines to form a closed-loop circulation circuit.

2. The integrated air-cooled small-scale organic Rankine cycle waste heat power generation system according to claim 1, characterized in that, The heat exchanger (7) is provided with a working fluid outlet pipe at the top, which is connected to the ORC expander (5). The heat exchanger (7) is provided with a working fluid inlet pipe (74) at the bottom, which is connected to the cam piston (17) pump assembly (1).

3. The integrated air-cooled small-scale organic Rankine cycle waste heat power generation system according to claim 1, characterized in that, The heat exchange chamber (71) has an elliptical cross-section, and the hot water inlet pipe (73) and hot water outlet pipe (72) are respectively located on both sides of the heat exchange chamber (71).

4. The integrated air-cooled small-scale organic Rankine cycle waste heat power generation system according to claim 1, characterized in that, The ORC expander (5) includes a housing with an inner cavity. A first inlet pipe (511) and a second inlet pipe (512) are respectively provided on opposite sides of the housing. An outlet is provided on the side of the housing. An impeller (53) is rotatably installed in the inner cavity. The first inlet pipe (511) and the second inlet pipe (512) are arranged opposite to each other. The working fluid entering the inner cavity through the first inlet pipe (511) and the second inlet pipe (512) merges in the inner cavity to form an annular tapered guide channel. The working fluid accelerated by the annular tapered guide channel impacts the impeller (53) to do work. The working fluid after doing work is discharged through the outlet.

5. The integrated air-cooled small-scale organic Rankine cycle waste heat power generation system according to claim 4, characterized in that, The impeller (53) includes a main shaft (531), which is connected to the generator (6) for transmission. The working fluid outlet pipe of the heat exchanger (7) is connected to the first inlet pipe (511) of the ORC expander (5). The working fluid outlet pipe of the heat exchanger (7) is connected to the cam piston (17) pump assembly (1). The outlet of the ORC expander (5) is connected to the condenser (3).

6. The integrated air-cooled small-scale organic Rankine cycle waste heat power generation system according to claim 1, characterized in that, The cam piston (17) pump assembly (1) includes a drive motor (11), one end of which is fixedly mounted with a bracket (12). A cylinder (13) is mounted on the bracket (12). One end of the cylinder (13) is provided with a first inlet pipe (141) and a first outlet pipe (142). The bracket (12) includes a base plate (533). The base plate (533) and the cylinder (13) form a closed space. The base plate (533) is provided with a second inlet pipe (142). 21) and the second outlet pipe (122), a cam piston (17) is movably installed inside the cylinder (13), the cam piston (17) divides the cylinder (13) into cavity A (131) and cavity B (132), the first inlet pipe (141) and the first outlet pipe (142) are connected to cavity A (131), the second inlet pipe (121) and the second outlet pipe (122) are connected to cavity B (132), and the cam piston (17) is connected to the drive motor (11) for transmission.

7. The integrated air-cooled small-scale organic Rankine cycle waste heat power generation system according to claim 6, characterized in that, The first inlet pipe (141) and the first outlet pipe (142) are connected by a first side pipe (2), and the second inlet pipe (121) and the second outlet pipe (122) are connected by a second side pipe (8). The first side pipe (2) is provided with a first branch pipe (21), and the second side pipe (8) is provided with a second branch pipe (21). The first branch pipe (21) is connected to the bottom of the condenser (3), and the second branch pipe (21) is connected to the working fluid inlet pipe (74).

8. The integrated air-cooled small-scale organic Rankine cycle waste heat power generation system according to claim 1, characterized in that, The condenser (3) is an air-cooled finned tube condenser (3), and the cooling fan (9) and the condenser (3) constitute an integrated air-cooled heat dissipation module.

9. The integrated air-cooled small-scale organic Rankine cycle waste heat power generation system according to claim 1, characterized in that, The organic working fluid is R245fa, a low-boiling-point working fluid.

10. The integrated air-cooled small-scale organic Rankine cycle waste heat power generation system according to claim 1, characterized in that, A pressure sensor is installed on the pipeline between the heat exchanger (7) and the ORC expander (5), and the pressure sensor signal is used to regulate the working fluid discharge pressure of the cam piston assembly in a closed loop.

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