阅读说明：本技术 一种低温余热发电系统 (Low-temperature waste heat power generation system ) 是由 袁军 钟仁志 于 2021-08-24 设计创作，主要内容包括：本发明涉及余热发电领域,尤其涉及一种低温余热发电系统。该系统包括换热蒸发设备、磁悬浮压缩膨胀一体设备、冷凝设备和工质储罐；磁悬浮压缩膨胀一体设备包括电机外壳、电机轴、磁轴承装置、膨胀涡轮、膨胀蜗壳、压缩叶轮和压缩蜗壳；膨胀涡轮和压缩叶轮分别固定连接至电机轴两端；膨胀蜗壳设置有膨胀通道,压缩蜗壳设置有压缩通道,膨胀涡轮和压缩叶轮分别位于膨胀通道和压缩通道内。该系统直接将膨胀涡轮转动的机械能转化为压缩叶轮的机械能,提高了整个系统发电效率。(The invention relates to the field of waste heat power generation, in particular to a low-temperature waste heat power generation system. The system comprises a heat exchange evaporation device, a magnetic suspension compression and expansion integrated device, a condensing device and a working medium storage tank; the magnetic suspension compression-expansion integrated equipment comprises a motor shell, a motor shaft, a magnetic bearing device, an expansion turbine, an expansion volute, a compression impeller and a compression volute; the expansion turbine and the compression impeller are respectively and fixedly connected to two ends of a motor shaft; the expansion volute is provided with an expansion channel, the compression volute is provided with a compression channel, and the expansion turbine and the compression impeller are respectively positioned in the expansion channel and the compression channel. The system directly converts the mechanical energy of the rotation of the expansion turbine into the mechanical energy of the compression impeller, and the power generation efficiency of the whole system is improved.)

1. A low-temperature waste heat power generation system is characterized by comprising a heat exchange evaporation device (1), a magnetic suspension compression and expansion integrated device (2), a condensing device (3) and a working medium storage tank (4); the magnetic suspension compression-expansion integrated equipment (2) comprises a motor shell (21), a motor shaft (22), a magnetic bearing device (23), an expansion turbine (24), an expansion volute (25), a compression impeller (26) and a compression volute (27); a motor stator (211) is embedded in an inner hole of the motor shell (21), a motor rotor (221) is arranged on the motor shaft (22), and the motor stator (211) corresponds to the motor rotor (221); the magnetic bearing device (23) is sleeved on the outer wall of the motor shaft (22), and the expansion turbine (24) and the compression impeller (26) are respectively and fixedly connected to the two ends of the motor shaft (22); the expansion volute (25) is provided with an expansion channel (251), the compression volute (27) is provided with a compression channel (271), and the expansion turbine (24) and the compression impeller (26) are respectively positioned in the expansion channel (251) and the compression channel (271); the output end of the heat exchange evaporation equipment (1) is communicated with the radial input end of the expansion channel (251), and the axial output end of the expansion channel (251) is communicated with the input end of the condensation equipment (3); the condensing equipment (3) is communicated with the axial input end of the compression channel (271) through the working medium storage tank (4), and the radial output end of the compression channel (271) is communicated with the input end of the heat exchange evaporation equipment (1).

2. The low temperature cogeneration system of claim 1, wherein the magnetic bearing means (23) comprises a radial magnetic bearing (231) and an axial magnetic bearing (232), the motor shaft (22) being fixedly provided with a radial bearing rotor (222) and a thrust disc (223); the two radial magnetic bearings (231) are respectively fixed on the motor shell (21), the supporting ends of the radial magnetic bearings (231) correspond to the radial bearing rotor (222), and the limiting ends of the two axial magnetic bearings (232) are respectively positioned at two axial sides of the thrust disc (223).

3. The low-temperature waste heat power generation system according to claim 1, wherein the magnetic bearing device (23) further comprises a radial-axial sensor (233), and a plurality of silicon steel sheets stacked along the axial direction are sleeved on the outer wall of the motor shaft (22); the plurality of radial and axial sensors (233) are respectively positioned at two ends of the motor shaft (22), and the sensing ends of the radial and axial sensors (233) are respectively aligned with the silicon steel sheets stacked at corresponding positions.

4. The low-temperature waste heat power generation system according to claim 1, wherein an inlet guide vane (252) is arranged at a radial input end of the expansion channel (251), and the inlet guide vane (252) is used for rectifying the heated high-pressure working medium when flowing into the expansion channel (251) so as to improve the expansion efficiency; the axial output end of the expansion channel (251) is provided with a labyrinth seal (253), the labyrinth seal (253) is located on the radial outer side of the air outlet end of the expansion turbine (24), and the labyrinth seal (253) is used for reducing leakage of compressed gas and improving expansion efficiency.

5. The low-temperature waste heat power generation system according to claim 1, wherein a radial output end of the compression passage (271) is provided with a diffuser vane (272), and the diffuser vane (272) is used for rectifying accelerated air flowing out of the compression impeller (26) to improve compression efficiency.

6. The low temperature cogeneration system of claim 1, wherein the expansion turbine (24) is a closed impeller structure and the expansion turbine (24) is a three-dimensional flow blade of an aerospace wrought aluminum material.

7. The low temperature cogeneration system of claim 1, wherein the compression impeller (26) is a semi-open impeller structure and the compression impeller (26) is a three-dimensional flow blade made of a titanium alloy material.

8. The low-temperature waste heat power generation system according to claim 1, wherein the inlet ends of the expansion turbine (24) and the compression impeller (26) are provided with fairings (241), and the fairings (241) are used for guiding the sucked air and improving the air inlet efficiency.

9. The low-temperature waste heat power generation system according to claim 1, wherein the motor housing (21) comprises a motor barrel (212), a front protection bearing seat (213) and a rear protection bearing seat (214), the front protection bearing seat (213) and the rear protection bearing seat (214) are respectively fixed at two ends of the motor barrel (212), and the expansion volute (25) and the compression volute (27) are respectively fixed on the outer side surfaces of the front protection bearing seat (213) and the rear protection bearing seat (214); o-shaped sealing rings are arranged between the front protection bearing seat (213) and the motor cylinder (212), between the rear protection bearing seat (214) and the motor cylinder (212), between the expansion volute (25) and the front protection bearing seat (213) and between the compression volute (27) and the rear protection bearing seat (214).

10. The low-temperature waste heat power generation system according to claim 9, wherein the magnetic suspension compression and expansion integrated device (2) is further provided with a protection bearing (5), and a plurality of protection bearings (5) are sleeved on the outer wall of the motor shaft (22) and are respectively arranged in inner holes of the front protection bearing seat (213) and the rear protection bearing seat (214); the outer ring of the protection bearing (5) is in interference fit with inner holes of the front protection bearing seat (213) and the rear protection bearing seat (214), and a gap exists between the inner ring of the protection bearing (5) and the outer wall of the motor shaft (22).

Technical Field

The invention relates to the field of waste heat power generation, in particular to a low-temperature waste heat power generation system.

Background

Waste heat power generation is a technology for converting redundant heat energy in the production process into electric energy. The waste heat power generation not only saves energy, but also is beneficial to environmental protection. It uses the heat or combustible substances in working media such as waste gas and waste liquid as heat source to produce steam for power generation. The waste heat for power generation mainly comprises high-temperature flue gas waste heat, chemical reaction waste heat, waste gas and waste liquid waste heat, low-temperature waste heat (lower than 200 ℃) and the like.

The Chinese utility model patent application (publication No. CN207348919U, published: 20180511) discloses a magnetic suspension waste heat power generation system, which comprises a heat exchanger, a magnetic suspension expander, a generator, a condenser and a magnetic pump; the working medium outlet of the heat exchanger is communicated with the inlet of the magnetic suspension expansion machine through a pipeline, the outlet of the magnetic suspension expansion machine is communicated with the working medium inlet of the condenser through a pipeline, the working medium outlet of the condenser is communicated with the inlet of the magnetic pump through a pipeline, and the outlet of the magnetic pump is communicated with the working medium inlet of the heat exchanger through a pipeline; the heat exchanger is provided with a waste heat outlet and a waste heat inlet, and the condenser is provided with a cooling inlet and a cooling outlet; the magnetic suspension expander is provided with a worm wheel, and the worm wheel is connected with the generator through a magnetic suspension rotating shaft. The generator is a variable frequency generator. The worm wheel, the magnetic suspension rotating shaft, the generator and the magnetic bearing are arranged in the same semi-closed shell. The magnetic suspension rotating shaft is sleeved with a magnetic bearing. The power generation system improves efficiency and power generation capacity, and belongs to the technical field of waste heat power generator sets.

The prior art has the following defects: in a traditional waste heat power generation system, a heat exchange evaporation device conveys a heated high-pressure working medium to an expansion power generation device to drive an expansion turbine of the expansion power generation device to rotate so as to generate power, and the high-pressure working medium is changed into a low-pressure working medium after acting and is cooled by a condensing device to enter a working medium storage tank; and then the expansion power generation equipment transmits part of electric energy to an external compression pump so as to compress the low-pressure working medium output by the working medium storage tank into a high-pressure working medium and transmit the high-pressure working medium to the heat exchange evaporation equipment to complete working medium circulation. In this way, the expansion process and the compression process are two independent processes, when the low-pressure working medium is compressed into the high-pressure working medium, the mechanical energy generated by the rotation of the expansion turbine needs to be converted into the electric energy of the expansion power generation equipment, and then the electric energy of the expansion power generation equipment is converted into the mechanical energy of the external compression pump to compress the low-pressure working medium; therefore, the compression process needs to be carried out for multiple times of energy transfer, and the power generation efficiency of the whole system is reduced.

Disclosure of Invention

The purpose of the invention is: aiming at the problems, the expansion turbine and the compression impeller are connected to the same motor shaft, so that the high-pressure working medium drives the expansion turbine to rotate and simultaneously drives the compression impeller to rotate to compress the low-pressure working medium; thereby the expansion process and the compression process are integrally completed, and the mechanical energy of the rotation of the expansion turbine is directly converted into the mechanical energy of the compression impeller; the low-temperature waste heat power generation system reduces the frequency of energy transfer and energy loss and improves the power generation efficiency of the whole system.

In order to achieve the purpose, the invention adopts the following technical scheme:

a low-temperature waste heat power generation system comprises a heat exchange evaporation device, a magnetic suspension compression and expansion integrated device, a condensing device and a working medium storage tank; the magnetic suspension compression-expansion integrated equipment comprises a motor shell, a motor shaft, a magnetic bearing device, an expansion turbine, an expansion volute, a compression impeller and a compression volute; a motor stator is embedded in an inner hole of the motor shell, a motor rotor is arranged on a motor shaft, and the motor stator corresponds to the motor rotor in position; the magnetic bearing device is sleeved on the outer wall of the motor shaft, and the expansion turbine and the compression impeller are respectively and fixedly connected to the two ends of the motor shaft; the expansion volute is provided with an expansion channel, the compression volute is provided with a compression channel, and the expansion turbine and the compression impeller are respectively positioned in the expansion channel and the compression channel; the output end of the heat exchange evaporation equipment is communicated with the radial input end of the expansion channel, and the axial output end of the expansion channel is communicated with the input end of the condensation equipment; the condensing equipment is communicated with the axial input end of the compression channel through the working medium storage tank, and the radial output end of the compression channel is communicated with the input end of the heat exchange evaporation equipment.

Preferably, the magnetic bearing device comprises a radial magnetic bearing and an axial magnetic bearing, and a radial bearing rotor and a thrust disc are fixedly arranged on a motor shaft; the two radial magnetic bearings are respectively fixed on the motor shell, the supporting ends of the radial magnetic bearings correspond to the position of a radial bearing rotor, and the limiting ends of the two axial magnetic bearings are respectively positioned at two axial sides of the thrust disc.

Preferably, the magnetic bearing device further comprises a radial-axial sensor, and a plurality of silicon steel sheets stacked along the axial direction are sleeved on the outer wall of the motor shaft; the radial and axial sensors are respectively positioned at two ends of the motor shaft, and the sensing ends of the radial and axial sensors are respectively aligned with the silicon steel sheets stacked at corresponding positions.

Preferably, the radial input end of the expansion channel is provided with an inlet guide vane, and the inlet guide vane is used for rectifying the heated high-pressure working medium when flowing into the expansion channel, so that the expansion efficiency is improved; the axial output end of the expansion channel is provided with labyrinth seals, the labyrinth seals are located on the radial outer side of the air outlet end of the expansion turbine, and the labyrinth seals are used for reducing leakage of compressed gas and improving expansion efficiency.

Preferably, the radial output end of the compression passage is provided with a diffuser, and the diffuser is used for rectifying accelerated air flowing out of the compression impeller, so that the compression efficiency is improved.

Preferably, the expansion turbine is a closed impeller structure, and the expansion turbine is a three-dimensional flow blade made of an aerospace forged aluminum material.

Preferably, the compression impeller is of a semi-open type impeller structure, and the compression impeller is a three-dimensional flow blade made of a titanium alloy material.

Preferably, the inlet ends of the expansion turbine and the compression impeller are provided with fairings for guiding the sucked air and improving the air inlet efficiency.

Preferably, the motor shell comprises a motor barrel, a front protection bearing seat and a rear protection bearing seat, the front protection bearing seat and the rear protection bearing seat are respectively fixed at two ends of the motor barrel, and the expansion volute and the compression volute are respectively fixed on the outer side surfaces of the front protection bearing seat and the rear protection bearing seat; o-shaped sealing rings are arranged between the front protection bearing seat and the motor cylinder, between the rear protection bearing seat and the motor cylinder, between the expansion volute and the front protection bearing seat and between the compression volute and the rear protection bearing seat.

Preferably, the magnetic suspension compression and expansion integrated equipment is also provided with a protective bearing, and a plurality of protective bearings are sleeved on the outer wall of the motor shaft and are respectively arranged in inner holes of the front protective bearing seat and the rear protective bearing seat; the outer ring of the protection bearing is in interference fit with inner holes of the front protection bearing seat and the rear protection bearing seat, and a gap exists between the inner ring of the protection bearing and the outer wall of the motor shaft.

The low-temperature waste heat power generation system adopting the technical scheme has the advantages that:

when the device works, the heat exchange evaporation device outputs the heated high-pressure working medium to the radial input end of the expansion channel of the magnetic suspension compression and expansion integrated device so as to push the expansion turbine to rotate, the expansion turbine drives the motor shaft to rotate while rotating, so that the magnetic suspension compression and expansion integrated device generates electricity, and the high-pressure working medium is changed into a low-pressure working medium after acting and enters a working medium storage tank after being cooled by the condensing device; and the motor shaft rotates and simultaneously drives the compression impeller to rotate so as to compress the cooled low-pressure working medium output by the working medium storage tank into a high-pressure working medium, and the high-pressure working medium is conveyed to the heat exchange evaporation equipment to complete working medium circulation. In the mode, the high-pressure working medium drives the expansion turbine to rotate and simultaneously drives the compression impeller to rotate so as to compress the low-pressure working medium; thereby the expansion process and the compression process are integrally completed, and the mechanical energy of the rotation of the expansion turbine is directly converted into the mechanical energy of the compression impeller; the frequency of energy transfer and energy loss are reduced, and the power generation efficiency of the whole system is improved. Meanwhile, in the traditional expansion process, the expansion machine drives the reduction gearbox to further drive the three-phase asynchronous generator, and the expansion machine is changed into the expansion turbine to directly drive the permanent magnet synchronous high-speed generator without arranging the reduction gearbox, so that the energy consumption of the reduction gearbox is reduced; moreover, the permanent magnet synchronous high-speed generator in the mode is supported by the magnetic bearing device, and a motor shaft does not have mechanical friction when rotating; therefore, the mechanical loss is reduced, and the power generation efficiency of the whole system is further improved.

Drawings

FIG. 1 is a schematic structural diagram of the present invention.

Fig. 2 is a schematic structural diagram of a magnetic suspension compression and expansion integrated device.

Fig. 3 is a schematic view of the expansion volute.

Fig. 4 is a schematic view of a compression scroll.

Fig. 5 is a schematic structural view of a front protective bearing seat.

Fig. 6 is a schematic diagram of the structure of the motor cartridge.

Fig. 7 is a schematic structural diagram of a rear protection bearing seat.

Fig. 8 is a schematic view of the structure of the motor shaft.

215-O-shaped sealing ring, L1-heated high-pressure working medium, L2-low-pressure working medium, L3-cooled low-pressure working medium and L4-high-pressure working medium.

Detailed Description

The following describes in detail embodiments of the present invention with reference to the drawings.

Example 1

As shown in fig. 2, the low-temperature waste heat power generation system includes a heat exchange evaporation device 1, a magnetic suspension compression and expansion integrated device 2, a condensation device 3 and a working medium storage tank 4; the magnetic suspension compression-expansion integrated device 2 comprises a motor shell 21, a motor shaft 22, a magnetic bearing device 23, an expansion turbine 24, an expansion volute 25, a compression impeller 26 and a compression volute 27; a motor stator 211 is embedded in an inner hole of the motor shell 21, a motor rotor 221 is arranged on the motor shaft 22, and the motor stator 211 corresponds to the motor rotor 221 in position; the magnetic bearing device 23 is sleeved on the outer wall of the motor shaft 22, and the expansion turbine 24 and the compression impeller 26 are respectively and fixedly connected to two ends of the motor shaft 22; the expansion volute 25 is provided with an expansion channel 251, the compression volute 27 is provided with a compression channel 271, and the expansion turbine 24 and the compression impeller 26 are respectively positioned in the expansion channel 251 and the compression channel 271; the output end of the heat exchange evaporation device 1 is communicated with the radial input end of an expansion channel 251, and the axial output end of the expansion channel 251 is communicated with the input end of a condensing device 3; the condensing equipment 3 is communicated with the axial input end of the compression channel 271 through the working medium storage tank 4, and the radial output end of the compression channel 271 is communicated with the input end of the heat exchange evaporating equipment 1. When the heat exchange and evaporation device works, the heat exchange and evaporation device 1 outputs the heated high-pressure working medium to the radial input end of the expansion channel 251 of the magnetic suspension compression and expansion integrated device 2 so as to push the expansion turbine 24 to rotate, the expansion turbine 24 rotates and simultaneously drives the motor shaft 22 to rotate so as to enable the magnetic suspension compression and expansion integrated device 2 to generate electricity, the high-pressure working medium is changed into a low-pressure working medium after acting, and the low-pressure working medium is cooled by the condensation device 3 and enters the working medium storage tank 4; the motor shaft 22 rotates and simultaneously drives the compression impeller 26 to rotate so as to compress the cooled low-pressure working medium output by the working medium storage tank 4 into a high-pressure working medium, and the high-pressure working medium is conveyed to the heat exchange evaporation equipment 1 to complete working medium circulation. In this way, the high-pressure working medium drives the expansion turbine 24 to rotate and simultaneously drives the compression impeller 26 to rotate so as to compress the low-pressure working medium; thereby integrally completing the expansion process and the compression process, and directly converting the mechanical energy of the rotation of the expansion turbine 24 into the mechanical energy of the compression impeller 26; the frequency of energy transfer and energy loss are reduced, and the power generation efficiency of the whole system is improved. Meanwhile, in the traditional expansion process, the expansion machine drives the reduction gearbox to further drive the three-phase asynchronous generator, and the expansion machine is changed into the expansion turbine 24 which directly drives the permanent magnet synchronous high-speed generator without arranging the reduction gearbox, so that the energy consumption of the reduction gearbox is reduced; moreover, the permanent magnet synchronous high-speed generator in this way is supported by the magnetic bearing device 23, and the motor shaft 22 does not have mechanical friction when rotating; therefore, the mechanical loss is reduced, and the power generation efficiency of the whole system is further improved.

The magnetic bearing device 23 comprises a radial magnetic bearing 231 and an axial magnetic bearing 232, and the motor shaft 22 is fixedly provided with a radial bearing rotor 222 and a thrust disc 223; the two radial magnetic bearings 231 are respectively fixed on the motor shell 21, the supporting ends of the radial magnetic bearings 231 correspond to the radial bearing rotor 222, and the limiting ends of the two axial magnetic bearings 232 are respectively located at two axial sides of the thrust disc 223. The radial magnetic bearing 231 radially supports the motor shaft 22 by controlling the radial position of the radial bearing rotor 222, and the axial magnetic bearing 232 axially limits the motor shaft 22 by controlling the axial position of the thrust disc 223.

The magnetic bearing device 23 further comprises a radial-axial sensor 233, and a plurality of silicon steel sheets stacked along the axial direction are sleeved on the outer wall of the motor shaft 22; the plurality of radial-axial sensors 233 are respectively located at both ends of the motor shaft 22, and sensing ends of the radial-axial sensors 233 are respectively aligned with the silicon steel sheets stacked at corresponding positions. The radial-axial sensor 233 controls the radial and axial positions of the motor shaft 22 by sensing the radial and axial positions of the silicon steel sheet and transmitting them to the radial magnetic bearing 231 and the axial magnetic bearing 232.

As shown in fig. 3, an inlet guide vane 252 is arranged at the radial input end of the expansion channel 251, and the inlet guide vane 252 is used for rectifying the heated high-pressure working medium when the high-pressure working medium flows into the expansion channel 251, so as to improve the expansion efficiency; the axial output end of the expansion channel 251 is provided with a labyrinth seal 253, the labyrinth seal 253 is positioned on the radial outer side of the air outlet end of the expansion turbine 24, and the labyrinth seal 253 is used for reducing the leakage of compressed gas and improving the expansion efficiency.

As shown in fig. 4, a radial output end of the compression passage 271 is provided with a diffuser vane 272, and the diffuser vane 272 is used for rectifying the accelerated air flowing out from the compression impeller 26, thereby improving the compression efficiency.

The expansion turbine 24 is a closed impeller structure, and the expansion turbine 24 is a three-dimensional flow blade made of aerospace forged aluminum material, so that the multistage variable efficiency is high, and the performance is stable.

The compression impeller 26 is a semi-open impeller structure, and the compression impeller 26 is a three-dimensional flow blade made of titanium alloy material, so that the multistage variable compressor has the advantages of high efficiency, stable performance and easiness in processing.

As shown in fig. 2, the inlet ends of the expansion turbine 24 and the compression impeller 26 are provided with a cowling 241, and the cowling 241 guides the sucked air to improve the inlet efficiency.

As shown in fig. 2 and 5-7, the motor housing 21 includes a motor barrel 212, a front protective bearing seat 213 and a rear protective bearing seat 214, the front protective bearing seat 213 and the rear protective bearing seat 214 are respectively fixed at two ends of the motor barrel 212, and the expansion volute 25 and the compression volute 27 are respectively fixed on outer side surfaces of the front protective bearing seat 213 and the rear protective bearing seat 214; o-ring seals are disposed between the front protective bearing seat 213 and the motor barrel 212, between the rear protective bearing seat 214 and the motor barrel 212, between the expansion volute 25 and the front protective bearing seat 213, and between the compression volute 27 and the rear protective bearing seat 214. Therefore, the inside and the outside of the magnetic suspension compression and expansion integrated equipment are isolated, and an internal circuit is protected from being influenced by working media.

The magnetic suspension compression and expansion integrated equipment 2 is also provided with a plurality of protective bearings 5, and the protective bearings 5 are sleeved on the outer wall of the motor shaft 22 and are respectively arranged in inner holes of the front protective bearing seat 213 and the rear protective bearing seat 214; the outer ring of the protection bearing 5 is in interference fit with the inner holes of the front protection bearing seat 213 and the rear protection bearing seat 214, and a gap exists between the inner ring of the protection bearing 5 and the outer wall of the motor shaft 22. When the equipment is suddenly powered off or stopped, the radial magnetic bearing 231 and the axial magnetic bearing 232 lose magnetic force and can not support and limit the motor shaft 22, and at the moment, the motor shaft 22 falls down and contacts with the inner ring of the protective bearing 5 to be supported by the protective bearing 11; thereby avoiding the damage of important parts such as the radial magnetic bearing 231 and the axial magnetic bearing 232 caused by the sudden power failure of the motor or the sudden falling of the motor shaft 22 when the motor is stopped.