Magnetic suspension low-temperature waste heat power generation system

Abstract

The invention belongs to the technical field of magnetic suspension low-temperature waste heat power generation, and discloses a magnetic suspension low-temperature waste heat power generation system which comprises a base, a condenser and a preheating evaporator are arranged on the base, and a turbo expander is arranged above the condenser. The inlet end of the turbo expander is communicated with the outlet end of the preheating evaporator through a gas-liquid separation communicating pipeline, the outlet end of the turbo expander is communicated with the condenser through a gas outlet pipe, and a pressurizing pipeline is arranged between the condenser and the preheating evaporator; the system has good real-time monitoring capability, the system can be automatically adjusted according to the operation condition of the equipment, and the evaporation efficiency and the maximum generating capacity are ensured.

Description

Technical Field

[0001] The present invention belongs to the technical field of magnetic levitation low-temperature waste heat power generation, and in particular, relates to a magnetic levitation low-temperature waste heat power generation system. Background Art

[0002] With the development of magnetic levitation technology, the organic Rankine cycle and magnetic levitation technology have begun to be applied in low-temperature waste heat power generation; the magnetic levitation low-temperature waste heat power generation unit absorbs waste heat through the evaporation of refrigerant in the heat exchanger. The refrigerant becomes gaseous after evaporation and drives the expander to rotate under the action of the working fluid, thereby driving the magnetic levitation generator to rotate and generate electricity. The gaseous refrigerant then reaches the condensation side, liquefies and is released into the cooling circulating water; the low-temperature waste heat power generation system makes good use of waste heat to convert low-temperature heat into electrical energy, thereby improving energy utilization.

[0003] The patent application number is: CN202222325784.8, which discloses an organic Rankine cycle power generation system and a low-temperature waste heat power generation system. The organic Rankine cycle power generation system includes a working fluid pump, an evaporator, an expander and a condenser connected by pipelines. The output end of the expander is connected to a generator to perform work on the generator; the organic Rankine cycle power generation system also includes a bypass flow path and a switching device. The bypass flow path is arranged in parallel with the expander, and the switching device is constructed to switch the bypass flow path and the expander.

[0004] The above-mentioned existing low-temperature waste heat power generation system adopts the organic Rankine cycle principle that the refrigerant circulates and drives the expander to do work to achieve power generation. However, the overall structure of this type of existing low-temperature waste heat power generation system is complex and there is serious surge phenomenon. In addition, the degree of automation is low and the operating data cannot be monitored in real time, thereby reducing the use effect. Summary of the invention

[0005] The main technical problem to be solved by the present invention is to provide a magnetic levitation low-temperature waste heat power generation system, the control system has good real-time monitoring capabilities, and can automatically adjust the system according to the equipment operation conditions to ensure evaporation efficiency and maximum power generation.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions: A magnetic levitation low-temperature waste heat power generation system comprises a base, on which a condenser and a preheating evaporator are arranged, a turbine expander is arranged above the condenser, the inlet end of the turbine expander is connected with the outlet end of the preheating evaporator through a gas-liquid separation connecting pipeline, the outlet end of the turbine expander is connected with the condenser through an air outlet pipe, and a boosting pipeline is arranged between the condenser and the preheating evaporator.

[0007] The following is a further optimization of the above technical solution by the present invention: The preheating evaporator comprises a preheater and an evaporator. The preheater is fixedly mounted on a base, and the evaporator is fixedly mounted above the preheater via a support frame. The outlet end of the preheater is connected to the inlet end of the evaporator.

[0008] Further optimization: the gas-liquid separation connecting pipeline includes a gas-liquid separator, which is fixedly installed on a base. The inlet end of the gas-liquid separator is connected to an air inlet pipe, and the other end of the air inlet pipe is connected to the outlet end of the evaporator; the outlet end of the gas-liquid separator is connected to an air inlet pipe, and the other end of the air inlet pipe is connected to the inlet end of the turbine expander.

[0009] Further optimization: the liquid outlet end of the gas-liquid separator is connected to a gas return pipe, the other end of the gas return pipe is connected to the preheater, and the refrigerant liquid separated from the gas and water in the gas-liquid separator flows back to the preheater through the gas return pipe.

[0010] Further optimization: an electric regulating valve is connected in series to the air inlet pipe, and the electric regulating valve is used to adjust the flow rate of the refrigerant flowing in the air inlet pipe. A bypass pipe is connected in series between the air inlet pipe and the air outlet pipe, and an electric bypass valve is connected in series to the bypass pipe. A bypass valve is also connected in series to the air outlet pipe.

[0011] Further optimization: the boosting pipeline includes a working fluid pump, a pump front liquid inlet pipe is connected in series to the inlet end of the working fluid pump, and the other end of the pump front liquid inlet pipe is connected to the condenser; a pump rear liquid inlet pipe is connected in series to the outlet end of the working fluid pump, and the other end of the pump rear liquid inlet pipe is connected to the preheater of the preheating evaporator.

[0012] Further optimization: A control cabinet is also installed on the base, a main controller is arranged in the control cabinet, an input end of the main controller is electrically connected to a first liquid level sensor, the first liquid level sensor is arranged in the condenser, and the first liquid level sensor is used to detect the liquid level of the refrigerant in the condenser.

[0013] Further optimization: the control ends of the electric regulating valve, bypass valve, electric bypass valve and working fluid pump are electrically connected to the main controller respectively, and the main controller sends a control signal for independently controlling the electric regulating valve, bypass valve, electric bypass valve and working fluid pump to work.

[0014] Further optimization: the output end of the main controller is electrically connected to a frequency converter, and the power output end of the frequency converter is electrically connected to the power output end of the turbine expander.

[0015] Further optimization: The input end of the main controller is electrically connected to a temperature sensor group and a pressure sensor group, and the temperature sensor group and the pressure sensor group are used to constantly detect the temperature and pressure at various locations within the magnetic levitation low-temperature waste heat power generation system.

[0016] The present invention adopts the above technical solution and has the following beneficial effects: 1. An electric regulating valve is installed on the air inlet pipe of the magnetic levitation turbine expander of the present invention, and a bypass valve is installed on the air outlet pipe of the magnetic levitation turbine expander. The electric regulating valve of the air inlet pipe and the outlet bypass valve can adjust the flow rate of the working medium in real time to prevent the magnetic levitation expander from running away and surging during startup, shutdown and operation.

[0017] 2. The first liquid level sensor is used to detect the liquid level of the working fluid in the condenser in real time. If the liquid level of the working fluid is too low, it will lead to low evaporation and prone to surge or suspension instability. If the liquid level is too high, the unit will absorb a large amount of heat and achieve low evaporation efficiency. The liquid level adaptive control ensures the system stability and high-efficiency operation of the generator set.

[0018] 3. The magnetic levitation turbine expander is controlled by the frequency converter during startup, and the speed is suppressed by the frequency converter in the power generation mode. The system loss in the turbine power generation state is small. Under the premise of ensuring the power generation, the grid connection and disconnection of the magnetic levitation turbine generator can be flexibly controlled.

[0019] 4. The main controller in the present invention can collect the real-time temperature, pressure and operating data of the magnetic levitation low-temperature waste heat power generation system during operation, realize the automatic operation of the on-site equipment, automatic optimization of power generation, self-adjustment of operating conditions, and realize automatic operation.

[0020] The present invention is further described below in conjunction with the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the overall structure of an embodiment of the present invention; Figure 2 A top view of the overall structure of an embodiment of the present invention; Figure 3 is a schematic diagram of the overall structure in an embodiment of the present invention; Figure 4 It is a control flow chart in an embodiment of the present invention.

[0022] In the figure: 1-base; 2-condenser; 3-air outlet pipe; 4-gas return pipe; 5-cooling spray pipe; 6-turbine expander; 7-cooling outlet pipe; 8-reverse circulation pipe; 9-control cabinet; 10-pump rear liquid inlet pipe; 11-working fluid pump; 12-preheating evaporator; 121-preheater; 122-evaporator; 13-pump front liquid inlet pipe; 14-inlet pipe; 15-bypass pipe; 16-gas-liquid separator; 17-inlet pipe; 18-electric regulating valve; 19-bypass valve. DETAILED DESCRIPTION

[0023] like Figure 1-4As shown: a magnetic levitation low-temperature waste heat power generation system, including a base 1, on which a condenser 2 and a preheating evaporator 12 are arranged, a turbine expander 6 is arranged above the condenser 2, the inlet end of the turbine expander 6 is connected to the outlet end of the preheating evaporator 12 through a gas-liquid separation connecting pipeline, the outlet end of the turbine expander 6 is connected to the condenser 2 through an outlet pipe 3, and a booster pipeline is arranged between the condenser 2 and the preheating evaporator 12.

[0024] In this embodiment, the preheating evaporator 12 includes a preheater 121 and an evaporator 122 . The preheater 121 is fixedly mounted on the base 1 , and the evaporator 122 is fixedly mounted above the preheater 121 via a support frame.

[0025] The outlet end of the preheater 121 is connected to the inlet end of the evaporator 122 . The refrigerant in the preheater 121 is preliminarily preheated and then transported to the evaporator 122 . At this time, the refrigerant absorbs heat and evaporates in the evaporator 122 .

[0026] In this embodiment, a heat exchanger is respectively provided in the preheater 121 and the evaporator 122. The inlet and outlet ends of the heat exchanger are respectively connected to the external circulating heat source through external pipelines. The external circulating heat source outputs heated circulating water which is transported to the heat exchanger through the pipeline. At this time, the heat exchanger heats the refrigerant in the preheater 121 and the evaporator 122 to convert the liquid refrigerant into a gaseous refrigerant.

[0027] The gas-liquid separation connecting pipeline includes a gas-liquid separator 16 , which is fixedly mounted on the base 1 . The inlet end of the gas-liquid separator 16 is connected to an air inlet pipe 17 , and the other end of the air inlet pipe 17 is connected to the outlet end of the evaporator 122 .

[0028] The outlet end of the gas-liquid separator 16 is connected to the air inlet pipe 14 , and the other end of the air inlet pipe 14 is connected to the inlet end of the turbine expander 6 .

[0029] In this design, after the refrigerant absorbs waste heat multiple times in the preheating evaporator 12, the refrigerant changes from liquid to gas, and the gaseous refrigerant is transported to the gas-liquid separator 16 through the intake pipe 17. At this time, the gas-liquid separator 16 separates the gaseous refrigerant into gas and liquid, and then transports it to the turbine expander 6 through the intake pipe 14; the turbine expander 6 is driven to rotate by the working fluid, and then rotates.

[0030] The liquid outlet end of the gas-liquid separator 16 is connected to a gas return pipe 4 , and the other end of the gas return pipe 4 is connected to the preheater 121 . The refrigerant liquid separated from the gas and water in the gas-liquid separator 16 flows back to the preheater 121 through the gas return pipe 4 .

[0031] The output end of the turbine expander 6 is electrically connected to a rectifier circuit, which includes a frequency converter, a PFC inductor, a filter capacitor and an inverter. The frequency converter is used to rectify the AC power input by the turbine expander 6 into DC power and maintain the required voltage value. The PFC inductor and the filter capacitor eliminate harmonics and improve the power factor. Secondly, the inverter converts the DC power into AC power and transmits the AC power to the power grid to complete the power generation process.

[0032] The gaseous refrigerant expands in the turbine expander 6 , and then the refrigerant output by the turbine expander 6 flows back to the condenser 2 through the outlet pipe 3 .

[0033] A heat exchanger is provided in the condenser 2, and the inlet and outlet ends of the heat exchanger are respectively connected to an external circulating cold source through external pipelines. The cooling circulating water output by the external circulating cold source is transported to the heat exchanger through the pipeline. At this time, the heat exchanger condenses the refrigerant in the condenser 2 to condense the gaseous refrigerant into liquid refrigerant. At this time, the refrigerant releases heat during the liquefaction process, and the heat is released into the cooling circulating water.

[0034] The air inlet pipe 14 is connected in series with an electric regulating valve 18 for regulating the flow rate of the refrigerant flowing in the air inlet pipe 14 . The air outlet pipe 3 is connected in series with a bypass valve 19 for regulating the flow rate of the refrigerant flowing in the air outlet pipe 3 .

[0035] By adjusting the opening of the electric regulating valve 18 and the bypass valve 19, the flow rate of the refrigerant in the air inlet pipe 14 and the air outlet pipe 3 can be adjusted to prevent the turbine expander 6 from running out of control or surging during startup, shutdown and operation.

[0036] The cooling channel inlet of the turbine expander 6 is connected to a cooling spray pipe 5, and the other end of the cooling spray pipe 5 is connected to the pump rear liquid inlet pipe 10. When the turbine expander 6 is running, the working fluid enters the cooling channel of the turbine expander 6 through the cooling spray pipe 5 to cool the stator and the magnetic bearing to prevent the expander from overheating.

[0037] The cooling channel outlet of the turbine expander 6 is connected to a cooling liquid outlet pipe 7 , and the other end of the cooling liquid outlet pipe 7 is connected to the condenser 2 . The working fluid discharged from the cooling channel of the turbine expander 6 flows back into the condenser 2 through the cooling liquid outlet pipe 7 .

[0038] The cooling liquid outlet pipe 7 is connected in series with a solenoid valve, which is used to control the on-off of the cooling liquid outlet pipe 7 for easy use.

[0039] The condenser 2 is connected to a reverse circulation pipe 8, and the other end of the reverse circulation pipe 8 is connected to a working fluid pump 11. The reverse circulation pipe can reduce the temperature inside the working fluid pump 11 to prevent damage due to high temperature. It can also prevent the working fluid from being retained in the pump for a long time, thereby extending the service life of the working fluid pump 11, protecting the working fluid pump 11, and ensuring stable and efficient operation.

[0040] The boost pipeline includes a working fluid pump 11 , and a pump front liquid pipe 13 is connected in series to the inlet end of the working fluid pump 11 , and the other end of the pump front liquid pipe 13 is connected to the condenser 2 .

[0041] A pump rear liquid inlet pipe 10 is connected in series to the outlet end of the working fluid pump 11 , and the other end of the pump rear liquid inlet pipe 10 is communicated with the preheater 121 of the preheating evaporator 12 .

[0042] The working medium pump 11 sucks the liquefied refrigerant in the condenser 2 through the pump front liquid inlet pipe 13, and after being pressurized, it is transported to the preheater 121 of the preheating evaporator 12 through the pump rear liquid inlet pipe 10, so that the refrigerant is circulated.

[0043] A bypass pipe 15 is connected in series between the air inlet pipe 14 and the air outlet pipe 3 , and an electric bypass valve is connected in series to the bypass pipe 15 . The electric bypass valve is used to adjust the flow rate of the refrigerant in the bypass pipe 15 , which is convenient for use.

[0044] By adjusting the opening of the electric regulating valve 18 and the electric bypass valve on the bypass pipe 15, the flow rate of the refrigerant entering the turbine expander 6 can be adjusted to prevent the turbine expander 6 from running out of speed and surging during startup, shutdown and operation.

[0045] A control cabinet 9 is also installed on the base 1. A main controller is arranged in the control cabinet 9. The input and output ends of the main controller are bidirectionally electrically connected to a control screen. The control screen is used to display and adjust the detection parameters and control parameters in the main controller. The control screen is installed on the control cabinet 9.

[0046] The input end of the main controller is electrically connected to a first liquid level sensor, which is disposed in the condenser 2 and is used to detect the liquid level of the refrigerant in the condenser 2 .

[0047] The first liquid level sensor is used to detect the liquid level of the refrigerant in the condenser 2 and send it to the main controller. If the liquid level of the refrigerant in the condenser 2 is too low, it will lead to low evaporation and thus prone to surge or suspension instability. If the liquid level is too high, it will cause the unit to absorb a large amount of heat and achieve low evaporation efficiency. The liquid level adaptive control ensures the system stability and high-efficiency operation of the generator set.

[0048] The control ends of the electric regulating valve 18, bypass valve 19, electric bypass valve and working fluid pump 11 are electrically connected to the main controller respectively, and the main controller sends control signals for independently controlling the electric regulating valve 18, bypass valve 19, electric bypass valve and working fluid pump 11 to work.

[0049] The output end of the main controller is electrically connected to a frequency converter, and the power output end of the frequency converter is electrically connected to the power output end of the turbine expander 6 .

[0050] The turbo expander 6 is a magnetically suspended turbo expander.

[0051] In this design, the main controller sends out a control signal for controlling the operation of the frequency converter, and the frequency converter is used to start the turbine expander 6. When the speed of the turbine expander 6 in the power generation mode is suppressed by the frequency converter, the system loss in the turbine power generation state is small. Under the premise of ensuring the power generation, the grid connection and disconnection of the magnetic levitation turbine generator can be flexibly controlled.

[0052] The input end of the main controller is electrically connected to a temperature sensor group and a pressure sensor group. The temperature sensor group includes multiple temperature sensors, which are respectively arranged in the condenser 2, the outlet pipe 3, the preheater 121, the evaporator 122, the intake pipe 14, the pump rear liquid inlet pipe 10 and the pump front liquid inlet pipe 13. The temperature sensor group is used to constantly detect the temperature of various locations in the magnetic levitation low-temperature waste heat power generation system.

[0053] The pressure sensor group includes multiple pressure sensors, which are respectively arranged in the condenser 2, the outlet pipe 3, the preheater 121, the evaporator 122, the intake pipe 14, the pump rear liquid inlet pipe 10 and the pump front liquid inlet pipe 13. The pressure sensor group is used to constantly detect the temperature of various locations in the magnetic levitation low-temperature waste heat power generation system.

[0054] The input end of the main controller is electrically connected to the detection end of the turbo expander 6 .

[0055] With this design, the main controller can collect the temperature, pressure and operating data of the turbine expander 6 of the magnetic levitation low-temperature waste heat power generation system in real time, realize the automatic operation of the on-site equipment, automatic optimization of power generation, self-adjustment of operating conditions, and realize automatic operation.

[0056] When in use, first start the circulating water at the preheating evaporator 12 and the condenser 2, then open the bypass valve 19 and the working fluid pump 11; then set the speed of the magnetic levitation turbine expander 6, and start the magnetic levitation low-temperature waste heat power generation system. After starting, the magnetic levitation turbine expander 6 begins to suspend.

[0057] As the inlet water temperature of the preheating evaporator 12 increases, the opening of the bypass valve 19 is gradually closed, and the opening of the electric regulating valve 18 is gradually increased; the steam drives the magnetic levitation turbine expander 6 to gradually increase the speed; after rectification by the inverter, the harmonics are eliminated by the PFC inductor and the filter capacitor, the power factor is increased, and it is converted into a DC bus voltage, and the DC power is converted into AC power through the inverter, and then converted into AC power after LC filtering and transmitted to the power grid, completing the power generation process.

[0058] For those skilled in the art, according to the teachings of the present invention, without departing from the principles and spirit of the present invention, changes, modifications, substitutions and variations made to the implementation methods are still within the protection scope of the present invention.

Claims

1. A magnetic levitation low-temperature waste heat power generation system, comprising a base (1), characterized in that: A condenser (2) and a preheating evaporator (12) are arranged on the base (1), a turbine expander (6) is arranged above the condenser (2), an inlet end of the turbine expander (6) is connected to an outlet end of the preheating evaporator (12) via a gas-liquid separation connecting pipeline, and an outlet end of the turbine expander (6) is connected to the condenser (2) via an air outlet pipe (3), and a pressurizing pipeline is arranged between the condenser (2) and the preheating evaporator (12).

2. A magnetic levitation low-temperature waste heat power generation system according to claim 1, characterized in that: The preheating evaporator (12) comprises a preheater (121) and an evaporator (122); the preheater (121) is fixedly mounted on the base (1); and the evaporator (122) is fixedly mounted above the preheater (121) via a support frame; the outlet end of the preheater (121) is in communication with the inlet end of the evaporator (122).

3. A magnetic levitation low-temperature waste heat power generation system according to claim 2, characterized in that: The gas-liquid separation connecting pipeline comprises a gas-liquid separator (16), the gas-liquid separator (16) being fixedly mounted on the base (1), the inlet end of the gas-liquid separator (16) being connected to an air inlet pipe (17), the other end of the air inlet pipe (17) being connected to an outlet end of the evaporator (122); the outlet end of the gas-liquid separator (16) being connected to an air inlet pipe (14), the other end of the air inlet pipe (14) being connected to an inlet end of the turbine expander (6).

4. The magnetic levitation low-temperature waste heat power generation system according to claim 3 is characterized in that: The liquid outlet end of the gas-liquid separator (16) is connected to a gas separation liquid return pipe (4), and the other end of the gas separation liquid return pipe (4) is connected to the preheater (121). The refrigerant liquid separated from the gas and water in the gas-liquid separator (16) flows back to the preheater (121) through the gas separation liquid return pipe (4).

5. The magnetic levitation low-temperature waste heat power generation system according to claim 4 is characterized in that: The air inlet pipe (14) is connected in series with an electric regulating valve (18), which is used to adjust the flow rate of the refrigerant flowing in the air inlet pipe (14). A bypass pipe (15) is connected in series between the air inlet pipe (14) and the air outlet pipe (3), and the bypass pipe (15) is connected in series with an electric bypass valve; the air outlet pipe (3) is also connected in series with a bypass valve (19).

6. The magnetic levitation low-temperature waste heat power generation system according to claim 5, characterized in that: The boosting pipeline comprises a working fluid pump (11), the inlet end of the working fluid pump (11) is connected in series with a pump front liquid inlet pipe (13), the other end of the pump front liquid inlet pipe (13) is connected to the condenser (2); the outlet end of the working fluid pump (11) is connected in series with a pump rear liquid inlet pipe (10), the other end of the pump rear liquid inlet pipe (10) is connected to a preheater (121) of a preheating evaporator (12).

7. The magnetic levitation low-temperature waste heat power generation system according to claim 6 is characterized by: A control cabinet (9) is also installed on the base (1), a main controller is arranged in the control cabinet (9), an input end of the main controller is electrically connected to a first liquid level sensor, the first liquid level sensor is arranged in the condenser (2), and the first liquid level sensor is used to detect the liquid level of the refrigerant in the condenser (2).

8. The magnetic levitation low-temperature waste heat power generation system according to claim 7 is characterized in that: The control ends of the electric regulating valve (18), the bypass valve (19), the electric bypass valve and the working fluid pump (11) are respectively electrically connected to a main controller, and the main controller sends a control signal for independently controlling the electric regulating valve (18), the bypass valve (19), the electric bypass valve and the working fluid pump (11) to operate.

9. The magnetic levitation low-temperature waste heat power generation system according to claim 8, characterized in that: The output end of the main controller is electrically connected to a frequency converter, and the power output end of the frequency converter is electrically connected to the power output end of the turbine expander (6).

10. The magnetic levitation low-temperature waste heat power generation system according to claim 9, characterized in that: The input end of the main controller is electrically connected to a temperature sensor group and a pressure sensor group, and the temperature sensor group and the pressure sensor group are used to constantly detect the temperature and pressure at various locations within the magnetic levitation low-temperature waste heat power generation system.

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