Thermodynamic cycle system applied to steam turbine

Abstract

The invention provides a thermodynamic cycle system applied to a steam turbine. The thermodynamic cycle system comprises a boiler, the steam turbine and a vortex tube. The boiler generates steam with first temperature; the steam turbine discharges a first path of steam with second temperature to the vortex tube, a second path of steam with second temperature is discharged to the liquid inlet of the boiler, the vortex tube separates the first path of steam into hot steam with third temperature and cold steam with fourth temperature, and the hot steam with third temperature is recycled to the steam turbine; the steam turbine drives mechanical equipment through hot steam with the third temperature, cold steam with the fourth temperature is discharged to the liquid inlet of the boiler, the third temperature is higher than the second temperature, and the fourth temperature is lower than the second temperature; wherein the cold steam with the fourth temperature cools the second path of steam to generate cooling liquid, the cooling liquid enters the boiler from a liquid inlet of the boiler, the steam with the first temperature is generated after heating, a vacuum water ring pump and a condenser are omitted, and energy is saved.

Description

Technical Field

[0001] This application relates to the technical field of steam turbines, and specifically to a thermodynamic cycle system using a steam turbine. Background Technology

[0002] Steam turbines are an important component of the steam-water system in thermal power generation. A steam turbine is a prime mover that uses steam as a working fluid. Through the main steam valve and the regulating valve, the steam passes through the stationary blades and the moving blades at high speed, expands and does work to drive the turbine rotor to rotate, thus converting the thermal energy of the steam into mechanical energy.

[0003] Currently, in thermal power plants, a power cycle system can be used to provide steam for the turbine cycle. However, how to save energy in the thermal cycle system has always been a problem that thermal power plants need to solve. Summary of the Invention

[0004] This application provides a thermodynamic cycle system for steam turbines to solve the technical problem of how to save energy in thermodynamic cycle systems.

[0005] This application provides a thermodynamic cycle system for a steam turbine, comprising: a boiler, a steam turbine, and a vortex tube; The boiler is used to generate steam with a first temperature; The steam turbine is used to drive mechanical equipment to work using the steam with a first temperature, discharge a first stream of steam with a second temperature to the vortex tube, and discharge a second stream of steam with a second temperature to the liquid inlet of the boiler, wherein the second temperature is lower than the first temperature; The vortex tube is used to separate the first steam stream into hot steam with a third temperature and cold steam with a fourth temperature, and to reuse the hot steam with the third temperature to the steam turbine so that the steam turbine can use the hot steam with the third temperature to drive mechanical equipment, and to discharge the cold steam with the fourth temperature towards the liquid inlet of the boiler. The third temperature is higher than the second temperature, and the fourth temperature is lower than the second temperature. In this process, after the second-pass steam discharged from the turbine is cooled by the cold steam with a fourth temperature, a cooling liquid is generated. The cooling liquid enters the boiler from the boiler inlet and is heated by the boiler to generate steam with a first temperature.

[0006] Optionally, a vacuum is generated based on the pressure of the second-path steam discharged from the turbine and the pressure of the cold steam with a fourth temperature discharged from the vortex tube. The vacuum is used to extract the gas in the second-path steam and the cold steam with a fourth temperature that has not been cooled into a cooling liquid.

[0007] Optionally, the vacuum pressure is not higher than -20 kPa.

[0008] Optionally, the fourth temperature is not lower than -20°C and not higher than 10°C.

[0009] Optionally, the third temperature is not lower than 70°C and not higher than 350°C. Optionally, a water ring pump is also included, which is used to deliver the cooling liquid to the inlet of the boiler.

[0010] Optionally, the mechanical device is a generator.

[0011] Optionally, the number of vortex tubes is multiple, and the number of the first steam path is the same as the number of vortex tubes; The steam turbine is specifically used to discharge multiple first-path steam to each vortex tube; Each vortex tube is specifically used to recycle the hot steam with the third temperature to the turbine, so that the turbine can use the hot steam with the third temperature provided by all the vortex tubes to drive the mechanical equipment. Each vortex tube is specifically used to discharge the cold steam with the fourth temperature toward the liquid inlet of the boiler; The cooling liquid is generated after the second steam discharged from the turbine is cooled by the cold steam with a fourth temperature. Specifically, the cooling liquid is generated after the second steam discharged from the turbine is cooled by the cold steam with a fourth temperature discharged from all the vortex tubes.

[0012] Optionally, the boiler is provided with a steam outlet having a first temperature, the steam turbine is provided with a steam inlet having a first temperature, a steam inlet having a third temperature, a first steam outlet and a second steam outlet, and the vortex tube is provided with a first steam inlet, a hot steam outlet having a third temperature and a cold steam outlet having a fourth temperature. A steam transmission pipe with a first temperature is provided between the steam outlet with a first temperature and the steam inlet with a first temperature; a first steam transmission pipe is provided between the first steam outlet and the first steam inlet; a third temperature transmission pipe is provided between the hot steam outlet with a third temperature and the hot steam inlet with a third temperature; a second steam transmission pipe is provided between the second steam outlet and a preset steam junction point; a fourth temperature steam transmission pipe is provided between the cold steam outlet with a fourth temperature and the steam junction point; and a cooling liquid transmission pipe is provided between the steam junction point and the liquid inlet.

[0013] Optionally, at least one vortex tube is selected as the master vortex tube among the plurality of vortex tubes. A controller for controlling the controlled vortex tubes other than the master vortex tube is provided on the master vortex tube. An information transceiver for information interaction with the controller is provided on each controlled vortex tube. A pressure sensor for measuring the pressure of the second steam outlet is provided at the second steam outlet of the steam turbine. The pressure sensor sends the measured pressure value of the second steam stream to the controller; The controller obtains the pressure value of the cold steam with the fourth temperature discharged by the main control vortex tube and the pressure value of the cold steam with the fourth temperature discharged by each controlled vortex tube according to the pressure value of the second steam and the preset vacuum pressure value. The controller sends the pressure value of the cold steam with the fourth temperature discharged by each controlled vortex tube to the transceiver of each controlled vortex tube. The vacuum pressure value is the pressure value of the vacuum generated by the pressure of the second steam discharged by the turbine and the pressure of the cold steam with the fourth temperature discharged by the vortex tube. The main control vortex tube discharges the cold steam with the fourth temperature according to the pressure value of the cold steam with the fourth temperature discharged by the main control vortex tube. Each controlled vortex tube discharges the cold steam at the fourth temperature according to the pressure value provided by the controller.

[0014] Optionally, a flow rate sensor for measuring the steam flow rate in the low-pressure cylinder is also provided on the steam turbine; The flow rate sensor sends the measured current steam flow rate of the low-pressure cylinder to the controller; The controller compares the current low-pressure cylinder steam flow rate with the preset low-pressure cylinder steam flow rate. If the current low-pressure cylinder steam flow rate is higher than the preset low-pressure cylinder steam flow rate, a vacuum pressure value matching the preset low-pressure cylinder steam flow rate is obtained as the matching vacuum pressure value. Based on the pressure value of the second steam path and the matching vacuum pressure value, the controller obtains the pressure adjustment value of the cold steam with the fourth temperature discharged by the main control vortex tube and the pressure adjustment value of the cold steam with the fourth temperature discharged by each controlled vortex tube. The controller then sends the pressure adjustment value of the cold steam with the fourth temperature discharged by each controlled vortex tube to the transceiver of each controlled vortex tube. The main control vortex tube discharges the cold steam with the fourth temperature according to the pressure adjustment value of the cold steam with the fourth temperature discharged by the main control vortex tube. Each controlled vortex tube discharges the cold steam at the fourth temperature according to the pressure adjustment value provided by the controller.

[0015] Compared with the prior art, the embodiments of this application have the following advantages: This application provides a thermodynamic cycle system for a steam turbine, comprising: a boiler, a steam turbine, and a vortex tube; the boiler is used to generate steam with a first temperature; the steam turbine is used to drive mechanical equipment using the steam with the first temperature, discharge a first stream of steam with a second temperature to the vortex tube, and discharge a second stream of steam with a second temperature towards the boiler's liquid inlet, the second temperature being lower than the first temperature; the vortex tube is used to separate hot steam with a third temperature and cold steam with a fourth temperature from the first stream of steam, reusing the hot steam with the third temperature back to the steam turbine so that the steam turbine can drive mechanical equipment using the hot steam with the third temperature, and discharge the cold steam with a fourth temperature towards the boiler's liquid inlet, the third temperature being higher than the second temperature, and the fourth temperature being lower than the second temperature; wherein, after the cold steam with the fourth temperature cools the second stream of steam discharged by the steam turbine, a cooling liquid is generated, the cooling liquid enters the boiler from the boiler's liquid inlet, is heated by the boiler, and generates steam with the first temperature.

[0016] This embodiment introduces a vortex tube into the thermodynamic cycle system. A portion of the steam discharged from the turbine can be used as the input steam for the vortex tube, and the hot steam discharged from the vortex tube can be used as part of the input steam for the turbine, thus forming a power circulation channel between the turbine and the vortex tube. If no vortex tube is introduced into the thermodynamic cycle system, all the steam discharged from the turbine will undergo cooling treatment. The resulting cooling liquid will enter the boiler, where it will be heated and discharged as steam at a first temperature, which will then be used as the input steam for the turbine. Therefore, by introducing the vortex tube into the thermodynamic cycle system, a portion of the steam discharged from the turbine does not need to be cooled and reheated, thus saving the energy required for cooling this portion of steam and the fuel required for reheating it.

[0017] In addition, using the cold steam output from the vortex tube to cool a portion of the steam discharged from the turbine is equivalent to replacing the existing technology that requires a condenser to cool all the steam discharged from the turbine. This reduces the number of condensers in the power cycle system and saves the energy required for the condenser to cool all the steam discharged from the turbine. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of a steam turbine thermodynamic cycle system in the prior art.

[0019] Figure 2 This is a schematic diagram of the first structure of the thermodynamic cycle system applied to a steam turbine in an embodiment of this application.

[0020] Figure 3 This is a schematic diagram of the second structure of the thermodynamic cycle system applied to a steam turbine in an embodiment of this application.

[0021] Figure label: 10: Boiler; 20: Steam turbine; 30: Condenser; 40: Vacuum water ring pump; 50: Vortex tube; 60: Steam confluence device. Detailed Implementation

[0022] Many specific details are set forth in the following description to provide a full understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of this application; therefore, this application is not limited to the specific embodiments disclosed below.

[0023] The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to limit the application. The descriptive terms used in this application and the appended claims, such as “first” and “second”, are not intended to limit quantity or sequence, but rather to distinguish information of the same type from one another.

[0024] The following is an explanation of some of the relevant terms used in the embodiments of this application: A vortex tube, also known as a vortex tube refrigeration tube, vortex cooler, etc., is a very simple energy separation device. It consists of a nozzle, a vortex chamber, a separation orifice plate, and hot and cold end tubes. During operation, high-speed rotating compressed air expands in the nozzle and then enters the vortex tube tangentially at a high speed. As the airflow rotates at high speed within the vortex tube, it undergoes centrifugal decompression at the center of the vortex and centrifugal pressurization at the outer ring of the turbine. The gas separates from the center of the vortex into two parts with unequal pressure and temperature: the airflow at the center is colder, while the airflow at the outer layer is hotter. By adjusting the ratio of the hot and cold airflows, optimal cooling or heating effects can be achieved. Currently, vortex tubes are mainly used in refrigeration equipment. A typical input pressure for a vortex tube is not less than 0.7 MPa, and the cooling temperature at the cold end can reach -45℃ to -60℃. Its applications are quite broad, including tool and machine tool cooling, electronic equipment heat dissipation, low-temperature food processing, and rapid cooling in laboratories. Meanwhile, the heating temperature at the hot air end can reach +130℃. The ratio of cold air to hot air can be adjusted, varying between 10% and 90%, and the minimum and maximum achievable temperatures are also related to the air flow rate.

[0025] In related technologies, such as Figure 1 As shown, the traditional steam turbine thermal cycle system involves sending superheated steam (generated in boiler 10) to steam turbine 20. Steam turbine 20 cools the input superheated steam to obtain low-temperature steam, which is then sent to condenser 30 for heat exchange, turning the low-temperature steam into condensate. The steam is then pumped out of the condenser by vacuum water ring pump 40, and the condensate is sent back to the boiler for recirculation. This process consumes a lot of energy and does not meet the requirements for low energy consumption and environmental protection.

[0026] In view of this, such as Figure 2 As shown, this application provides a thermodynamic cycle system for a steam turbine, including: a boiler 10, a steam turbine 20, and a vortex tube 50; the boiler 10 is used to generate steam with a first temperature; the steam turbine 20 is used to drive mechanical equipment using the steam with the first temperature, discharge a first stream of steam with a second temperature to the vortex tube 50, and discharge a second stream of steam with a second temperature lower than the first temperature towards the liquid inlet of the boiler 10; the vortex tube 50 is used to separate the first stream of steam into hot steam with a third temperature and cold steam with a fourth temperature. Steam, having a third temperature, is recycled back to the steam turbine 20 so that the steam turbine 20 uses the hot steam with the third temperature to drive mechanical equipment and discharges cold steam with a fourth temperature toward the liquid inlet of the boiler. The third temperature is higher than the second temperature, and the fourth temperature is lower than the second temperature. Cooling liquid is generated after the second-path steam discharged from the steam turbine is cooled by the cold steam with the fourth temperature. The cooling liquid enters the boiler 10 from the liquid inlet and is heated by the boiler 10 to generate steam with a first temperature.

[0027] In other words, this embodiment introduces a vortex tube 50 into the thermodynamic cycle system. A portion of the steam discharged from the turbine 20 can serve as the input steam for the vortex tube 50, and the hot steam discharged from the vortex tube 50 can serve as a portion of the input steam for the turbine, thus forming a power circulation channel between the turbine and the vortex tube. If no vortex tube is introduced into the thermodynamic cycle system, all the steam discharged from the turbine will undergo cooling treatment. The resulting cooling liquid will enter the boiler, where the boiler 10 will heat the cooling liquid and discharge steam at a first temperature as the input steam for the turbine. Therefore, by introducing a vortex tube into the thermodynamic cycle system, a portion of the steam discharged from the turbine does not need to be cooled and reheated, thus saving the energy required for cooling this portion of steam and the fuel required for reheating it.

[0028] In addition, using the cold steam output from the vortex tube 50 to cool a portion of the steam discharged from the turbine is equivalent to replacing the existing technology that requires a condenser to cool all the steam discharged from the turbine. This reduces the number of condensers in the power cycle system and saves the energy required for the condenser to cool all the steam discharged from the turbine.

[0029] Next, with reference to the accompanying drawings, a detailed description will be given of a thermodynamic cycle system for steam turbines provided in this application.

[0030] like Figure 2 As shown, this application provides a thermodynamic cycle system for a steam turbine, including: a boiler 10, a steam turbine 20, and a vortex tube 50. The boiler 10 is used to generate steam with a first temperature. In this embodiment, the boiler 10 is a boiler used to heat a cooling liquid entering the boiler. The cooling liquid can be condensate, that is, the boiler heats the condensate into steam with a first temperature. The steam with the first temperature enters the steam turbine 20, therefore the steam with the first temperature is superheated steam, with a temperature of 350℃-550℃. The superheated steam with the first temperature at the inlet of the steam turbine 20 has the following advantages.

[0031] 1. Preventing water hammer: Superheated steam refers to steam with a temperature exceeding its saturation temperature. If saturated steam or wet steam containing liquid water is used, the steam may rapidly condense into water droplets as it passes through the turbine nozzles and blades due to the pressure drop, leading to water hammer. Water droplets have a mass much larger than the steam, causing a strong mechanical impact on the blades, resulting in vibration, damage, or even destruction of turbine components.

[0032] 2. Improved thermal efficiency: Superheated steam contains more thermal energy because its temperature exceeds the saturation temperature. This means that in a steam turbine, superheated steam can release more thermal energy and convert it into mechanical energy during its expansion and work, thereby improving thermal efficiency and output power.

[0033] 3. Ensure equipment safety: Superheated steam is less likely to condense even when the pressure drops, which helps maintain stable operating conditions inside the turbine, avoids corrosion and wear problems caused by steam condensation, and extends equipment life.

[0034] 4. Optimize operating conditions: When designing a steam turbine, its structure and operating parameters are optimized according to the characteristics of superheated steam, such as blade shape and nozzle configuration, in order to make full use of the high enthalpy characteristics of superheated steam and achieve efficient conversion.

[0035] 5. Avoid material limitations: While excessively high steam temperatures can be limited by the heat resistance of turbine materials, superheated steam provides a way to improve thermal efficiency within a safe temperature range, avoiding the material damage that may result from directly using higher temperatures.

[0036] In summary, using superheated steam at the inlet of turbine 20 with a first temperature is to ensure the safe and efficient operation of turbine 20, while avoiding potential hazards such as water hammer.

[0037] It can be understood that the temperature of the steam with the first temperature is the temperature of the steam at the inlet of the steam turbine 20. The inlet temperature requirements of steam turbines 20 with different capacities are different, and the temperature of the steam with the first temperature can be set according to the capacity of the steam turbine 20.

[0038] Steam with a first temperature enters the turbine 20 through the inlet. The turbine 20 is used to drive mechanical equipment using the steam with the first temperature, discharges a first stream of steam with a second temperature to the vortex tube 50, and discharges a second stream of steam with a second temperature lower than the first temperature towards the liquid inlet of the boiler 10.

[0039] This can be understood as follows: the steam turbine 20 uses steam with a first temperature entering the turbine 20 to drive mechanical equipment, which is a generator. After being processed in the turbine 20, the steam with the first temperature is discharged as a first-path steam with a second temperature and a second-path steam with a second temperature. The first-path steam with the second temperature enters the vortex tube 50, and the second-path steam with the second temperature is discharged towards the liquid inlet of the boiler 10, i.e., towards the liquid inlet of the boiler. This second-temperature steam can be understood as the temperature of saturated steam corresponding to 0.4 MPa-2 MPa. By consulting a saturated steam temperature table, the temperature of the second-temperature steam is found to be 143.642℃-212.417℃.

[0040] The first stream of steam enters the vortex tube 50. The vortex tube 50 is used to separate the first stream of steam into hot steam with a third temperature and cold steam with a fourth temperature. The hot steam with the third temperature is provided to the steam turbine 20 so that the steam turbine 20 can use the steam with the first temperature and the hot steam with the third temperature to drive mechanical equipment, and discharge the cold steam with the fourth temperature towards the liquid inlet of the boiler. The third temperature is higher than the second temperature, and the fourth temperature is lower than the second temperature.

[0041] The vortex tube consists of an air inlet, a cooling section, a heating section, and an air outlet. The air outlet is divided into a cold end air outlet and a hot end air outlet. The cold end air outlet is used to discharge steam from the cooling section, and the hot end air outlet is used to discharge steam from the heating section.

[0042] This can be understood as follows: the first stream of steam undergoes cooling and heating treatment in the vortex tube 50, which separates the incoming first stream of steam into hot steam with a third temperature and cold steam with a fourth temperature. The hot steam with the third temperature circulates at high speed and is discharged outward along the tube wall of the vortex tube 50, i.e., the hot steam with the third temperature is discharged from the hot end outlet and enters the steam turbine 20, where it mixes with the steam with the first temperature. The steam turbine 20 uses the steam with the first temperature and the hot steam with the third temperature to drive the mechanical equipment, i.e., to drive the generator to generate electricity. The hot steam with the third temperature returns to the steam turbine 20 for recycling, which can save energy. The cold steam with the fourth temperature is discharged from the cold end outlet and is discharged in the direction of the liquid inlet of the boiler 10, i.e., towards the liquid inlet in the direction of the boiler.

[0043] The hot steam at the third temperature is discharged from the hot end outlet of the vortex tube 50, meaning the third temperature is not lower than 70°C and not higher than 350°C. The cold steam at the fourth temperature is discharged from the cold end outlet of the vortex tube, meaning the fourth temperature is not lower than -20°C and not higher than 10°C.

[0044] In this process, after the second steam discharged from the turbine is cooled by the cold steam at the fourth temperature, a cooling liquid is generated. The cooling liquid enters the boiler from the boiler inlet and is heated by the boiler 10 to generate steam at the first temperature.

[0045] This can be understood as follows: both the cold steam with the fourth temperature and the second-path steam are discharged towards the liquid inlet of the boiler. That is, the cold steam with the fourth temperature cools the second-path steam and produces cooling liquid, i.e., condensate. The condensate is then supplied to the boiler, where it is heated to produce steam with a first temperature. This first-temperature steam is discharged from the boiler and enters the steam turbine for recirculation.

[0046] A vacuum is generated based on the pressure of the second-path steam discharged from the steam turbine 20 and the pressure of the cold steam with a fourth temperature discharged from the vortex tube 50. The vacuum is used to extract the gas in the second-path steam and the cold steam with a fourth temperature that has not been cooled into a cooling liquid.

[0047] This can be understood as follows: when the cold steam with the fourth temperature cools the second-pass steam, the pressure of the cold steam with the fourth temperature and the pressure of the second-pass steam create a vacuum. This vacuum is used to remove any gas in the second-pass steam and the cold steam with the fourth temperature that has not been cooled into a cooling liquid. The vacuum pressure is no higher than -20 kPa. In other words, in this embodiment, by creating a vacuum based on the pressure of the second-pass steam discharged from the turbine 20 and the pressure of the cold steam with the fourth temperature discharged from the vortex tube, a condenser and a vacuum water ring pump can be replaced, saving energy and further meeting the environmental protection requirements for low energy consumption. Moreover, this embodiment does not involve a rotational transmission device; it is applied to energy saving in turbine power generation by using the pressure of the second-pass steam from the turbine as the power source for the vortex tube.

[0048] In this embodiment of the application, when 1 ton of steam is completely cooled into condensate, under the condition that the temperature remains constant, the volume of 1 ton of steam is reduced by more than 1600 times relative to the volume of 1 ton of condensate, which can be calculated using the following formula: It can be seen that, for the same mass, volume is inversely proportional to the corresponding density. As is well known, at 100℃, the density of water vapor is approximately 0.6 kg / m³. 3 The density of water is approximately 10. 3 kg / m 3 ,Right now: , ,but In other words, the volume of 1 ton of steam is reduced by more than 1600 times compared to the volume of 1 ton of condensate.

[0049] By reducing the size, a huge pressure difference can be formed at the tail section of the steam turbine, thereby making the steam turbine more efficient in generating electricity and reducing coal consumption.

[0050] In the embodiments of this application, under the condition that the vacuum pressure is not higher than -20 kPa, under the same conditions and in the prior art, a steam turbine requires about 305g of standard coal to generate 1 kWh of electricity. However, in this application, a steam turbine requires about 295g of standard coal to generate 1 kWh of electricity. That is, a steam turbine can save about 10g of standard coal to generate 1 kWh of electricity. For large power plants, this can reduce coal consumption.

[0051] The circulation system also includes a water ring pump, which delivers the cooling liquid to the boiler inlet. This can be understood as the water ring pump delivering the condensate to the boiler inlet, allowing the condensate to be heated in the boiler and then circulated again.

[0052] Among them, such as Figure 3 As shown, there are multiple vortex tubes 50, and the number of first-path steam paths is the same as the number of vortex tubes 50. The steam turbine 20 is specifically used to discharge multiple first-path steam paths to each vortex tube. Each vortex tube is specifically used to reuse the hot steam with a third temperature to the steam turbine, so that the steam turbine can use the hot steam with a third temperature provided by all the vortex tubes to drive mechanical equipment. Each vortex tube is specifically used to discharge cold steam with a fourth temperature towards the liquid inlet of the boiler. The generation of cooling liquid after the second-path steam discharged by the steam turbine is cooled by the cold steam with a fourth temperature is specifically: the cooling liquid is generated after the second-path steam discharged by the steam turbine is cooled by the cold steam with a fourth temperature discharged by all the vortex tubes.

[0053] This can be understood as multiple vortex tubes operating in parallel, meaning there are multiple vortex tubes 50, and the number of vortex tubes 50 is the same as the number of the first steam paths. Each first steam path discharged from the turbine corresponds to one vortex tube 50, meaning each first steam path can be discharged into a corresponding vortex tube 50. The first steam path undergoes hot-cold separation in the corresponding vortex tube 50, separating into hot steam with a third temperature and cold steam with a fourth temperature. The hot steam with the third temperature is provided to the turbine 20, allowing the turbine 20 to use it to drive a generator to produce electricity. The hot steam with the third temperature is returned to the turbine for continued recycling, saving energy. Simultaneously, each vortex tube 50 also discharges the separated cold steam with the fourth temperature towards the boiler's inlet, allowing the cold steam with the fourth temperature discharged from the vortex tube 50 to cool the second steam path discharged from the turbine 20 and produce condensate.

[0054] In other words, when multiple vortex tubes 50 are connected in parallel, it is only necessary to input the second stream of steam discharged from the turbine 20 into each corresponding vortex tube 50. The working principle of each vortex tube 50 is the same as that of a single vortex tube connected previously.

[0055] The boiler 10 is provided with a steam outlet having a first temperature; the steam turbine 20 is provided with a steam inlet having a first temperature, a steam inlet having a third temperature, a first steam outlet, and a second steam outlet; the vortex tube is provided with a first steam inlet, a hot steam outlet having a third temperature, and a cold steam outlet having a fourth temperature; a steam transmission pipe having a first temperature is provided between the steam outlet having a first temperature and the steam inlet having a first temperature; a first steam transmission pipe is provided between the first steam outlet and the first steam inlet; a third temperature transmission pipe is provided between the hot steam outlet having a third temperature and the hot steam inlet having a third temperature; a second steam transmission pipe is provided between the second steam outlet and a preset steam junction point; a fourth temperature steam transmission pipe is provided between the cold steam outlet having a fourth temperature and the steam junction point; and a cooling liquid transmission pipe is provided between the steam junction point and the liquid inlet.

[0056] In this embodiment, the boiler 10 is provided with a steam outlet having a first temperature, i.e., the steam outlet having the first temperature is located at the upper end of the boiler. The steam turbine is provided with a steam inlet having the first temperature and a hot steam inlet having a third temperature; the first steam inlet and the third hot steam inlet can be located at the same end of the steam turbine or at different ends. The steam turbine is also provided with a first steam outlet having second temperature and a second steam outlet having second temperature; the first steam outlet and the second steam outlet can be located at the same end of the steam turbine or at different ends. The vortex tube is provided with the first steam inlet, the hot steam outlet having the third temperature, and a cold steam outlet having a fourth temperature.

[0057] In other words, the corresponding steam inlet and outlet can be connected via a transmission pipe. Specifically, the first-temperature steam transmission pipe connects a boiler with a first-temperature steam outlet to a steam turbine with a first-temperature steam inlet. The steam with the first temperature outputs from the boiler's first-temperature steam outlet, enters through the first-temperature steam transmission pipe, and then enters the steam turbine through the first-temperature steam inlet. In the steam turbine, it undergoes cooling to become second-temperature steam. Within the steam turbine, the second-temperature steam is divided into a first-path steam and a second-path steam. The first-path steam outputs from the first-path steam outlet on the steam turbine, enters through the first-path steam transmission pipe, and then enters the vortex tube through the first-path steam inlet on the turbine tube. In other words, the first-path steam transmission pipe connects the steam turbine and the vortex tube through the first-path steam outlet on the steam turbine and the first-path steam inlet on the vortex tube. The first stream of steam undergoes hot-cold separation in the vortex tube, separating it into hot steam with a third temperature and cold steam with a fourth temperature. The hot steam with the third temperature separated in the vortex tube exits from the third-temperature hot steam outlet, enters through the third-temperature transmission pipe, and then enters the steam turbine through the third-temperature hot steam inlet for recycling and energy saving. The second stream of steam in the steam turbine exits from the second steam outlet, enters through the second steam transmission pipe, and enters a predetermined steam confluence point. The cold steam with the fourth temperature separated in the vortex tube exits from the fourth-temperature cold steam outlet, enters through the fourth-temperature steam transmission pipe, and enters the steam confluence point. At the confluence point, the second stream of steam undergoes cooling treatment, producing cooling liquid, i.e., condensate. This cooling liquid is then transported through the cooling liquid transmission pipe to the inlet on the boiler, where it enters the boiler for heating and further recycling.

[0058] In this configuration, at least one vortex tube is selected as the master vortex tube. A controller is installed on the master vortex tube to control the other controlled vortex tubes. Each controlled vortex tube is equipped with a transceiver for communication with the controller. A pressure sensor is installed at the second steam outlet of the turbine to measure the pressure of the second-channel steam. The pressure sensor sends the measured pressure value of the second-channel steam to the controller. The controller, based on the pressure value of the second-channel steam and a preset vacuum pressure value, obtains the pressure value of the cold steam with a fourth temperature discharged from the master vortex tube. The pressure value of the cold steam with the fourth temperature discharged by each controlled vortex tube is sent to the transceiver of each controlled vortex tube. The vacuum pressure value is the vacuum pressure value generated based on the pressure of the second steam discharged from the turbine and the pressure of the cold steam with the fourth temperature discharged by the vortex tube. The main controlled vortex tube discharges the cold steam with the fourth temperature according to the pressure value of the cold steam with the fourth temperature discharged by the main controlled vortex tube. Each controlled vortex tube discharges the cold steam with the fourth temperature according to the pressure value of the cold steam with the fourth temperature discharged by the controller.

[0059] The turbine is equipped with a flow velocity sensor for measuring the steam velocity in the low-pressure cylinder. The flow velocity sensor sends the measured current steam velocity in the low-pressure cylinder to the controller. The controller compares the current steam velocity in the low-pressure cylinder with a preset steam velocity in the low-pressure cylinder. If the current steam velocity is higher than the preset steam velocity, a vacuum pressure value matching the preset steam velocity is obtained as the matching vacuum pressure value. Based on the pressure value of the second-path steam and the matching vacuum pressure value, the discharge velocity from the main control vortex tube is determined. The pressure adjustment value of the cold steam with a fourth temperature and the pressure adjustment value of the cold steam with the fourth temperature discharged by each controlled vortex tube are respectively sent to the transceiver of each controlled vortex tube; the main controlled vortex tube discharges the cold steam with the fourth temperature according to the pressure adjustment value of the cold steam with the fourth temperature discharged by the main controlled vortex tube; each controlled vortex tube discharges the cold steam with the fourth temperature according to the pressure adjustment value of the cold steam with the fourth temperature discharged by the controller.

[0060] The lower the exhaust pressure of a steam turbine, the higher the thermal efficiency of the steam cycle. However, the exhaust pressure mainly depends on the vacuum level of the condenser, which in turn depends on the temperature of the cooling water and the vacuum pump. If too low an exhaust pressure is used, it is necessary to increase the cooling water flow rate, increase the heat exchange surface between the condenser cooling water and the cooling medium, reduce the temperature of the cooling water used, and use a longer vacuum pump and last-stage blades. However, too low a vacuum will also cause the steam velocity in the turbine cylinder (low-pressure cylinder) to increase, which will aggravate the differential expansion of the turbine cylinder (low-pressure cylinder) and endanger the safe operation of the turbine.

[0061] Although this application discloses preferred embodiments as described above, it is not intended to limit this application. Any person skilled in the art can make possible changes and modifications without departing from the spirit and scope of this application. Therefore, the scope of protection of this application should be determined by the scope defined in the claims of this application.

Claims

1. A thermodynamic cycle system applied to a steam turbine, characterized in that, include: Boilers, steam turbines, and vortex tubes; The boiler is used to generate steam with a first temperature; The steam turbine is used to drive mechanical equipment to work using the steam with a first temperature, discharge a first stream of steam with a second temperature to the vortex tube, and discharge a second stream of steam with a second temperature to the liquid inlet of the boiler, wherein the second temperature is lower than the first temperature; The vortex tube is used to separate the first steam stream into hot steam with a third temperature and cold steam with a fourth temperature, and to reuse the hot steam with the third temperature to the steam turbine so that the steam turbine can use the hot steam with the third temperature to drive mechanical equipment, and to discharge the cold steam with the fourth temperature towards the liquid inlet of the boiler. The third temperature is higher than the second temperature, and the fourth temperature is lower than the second temperature. In this process, after the second-pass steam discharged from the turbine is cooled by the cold steam with a fourth temperature, a cooling liquid is generated. The cooling liquid enters the boiler from the boiler inlet and is heated by the boiler to generate steam with a first temperature.

2. The system according to claim 1, characterized in that, A vacuum is generated based on the pressure of the second-path steam discharged from the turbine and the pressure of the cold steam with a fourth temperature discharged from the vortex tube. The vacuum is used to extract gases that have not been cooled into a cooling liquid from the second-path steam and the cold steam with a fourth temperature.

3. The system according to claim 2, characterized in that, The vacuum pressure is not higher than -20 kPa.

4. The system according to claim 1, characterized in that, The fourth temperature is not lower than -20°C and not higher than 10°C; the third temperature is not lower than 70°C and not higher than 350°C.

5. The system according to claim 1, characterized in that, It also includes a water ring pump, which is used to deliver the cooling liquid to the inlet of the boiler.

6. The system according to claim 1, characterized in that, The mechanical device is a generator.

7. The system according to claim 1, characterized in that, The number of vortex tubes is multiple, and the number of the first steam path is the same as the number of vortex tubes; The steam turbine is specifically used to discharge multiple first-path steam to each vortex tube; Each vortex tube is specifically used to supply the hot steam with a third temperature to the steam turbine, so that the steam turbine can drive mechanical equipment using the steam with a first temperature and the hot steam with a third temperature supplied by all the vortex tubes; Each vortex tube is specifically used to discharge the cold steam with the fourth temperature toward the liquid inlet of the boiler; The cooling liquid is generated after the second steam discharged from the turbine is cooled by the cold steam with a fourth temperature. Specifically, the cooling liquid is generated after the second steam discharged from the turbine is cooled by the cold steam with a fourth temperature discharged from all the vortex tubes.

8. The system according to claim 1, characterized in that, The boiler is provided with a steam outlet with a first temperature, the steam turbine is provided with a steam inlet with a first temperature, a steam inlet with a third temperature, a first steam outlet and a second steam outlet, and the vortex tube is provided with a first steam inlet, a hot steam outlet with a third temperature and a cold steam outlet with a fourth temperature. A steam transmission pipe with a first temperature is provided between the steam outlet with a first temperature and the steam inlet with a first temperature; a first steam transmission pipe is provided between the first steam outlet and the first steam inlet; a third temperature transmission pipe is provided between the hot steam outlet with a third temperature and the hot steam inlet with a third temperature; a second steam transmission pipe is provided between the second steam outlet and a preset steam junction point; a fourth temperature steam transmission pipe is provided between the cold steam outlet with a fourth temperature and the steam junction point; and a cooling liquid transmission pipe is provided between the steam junction point and the liquid inlet.

9. The system according to claim 7, characterized in that, At least one vortex tube is selected as the master vortex tube among a plurality of vortex tubes. A controller is provided on the master vortex tube for controlling the controlled vortex tubes other than the master vortex tube among the plurality of vortex tubes. An information transceiver is provided on each controlled vortex tube for information interaction with the controller. A pressure sensor is provided at the second steam outlet of the steam turbine for measuring the pressure of the second steam. The pressure sensor sends the measured pressure value of the second steam stream to the controller; The controller obtains the pressure value of the cold steam with the fourth temperature discharged by the main control vortex tube and the pressure value of the cold steam with the fourth temperature discharged by each controlled vortex tube according to the pressure value of the second steam and the preset vacuum pressure value. The controller sends the pressure value of the cold steam with the fourth temperature discharged by each controlled vortex tube to the transceiver of each controlled vortex tube. The vacuum pressure value is the pressure value of the vacuum generated by the pressure of the second steam discharged by the turbine and the pressure of the cold steam with the fourth temperature discharged by the vortex tube. The main control vortex tube discharges the cold steam with the fourth temperature according to the pressure value of the cold steam with the fourth temperature discharged by the main control vortex tube. Each controlled vortex tube discharges the cold steam at the fourth temperature according to the pressure value provided by the controller.

10. The system according to claim 9, characterized in that, A flow rate sensor for measuring the steam flow rate in the low-pressure cylinder is also installed on the steam turbine; The flow rate sensor sends the measured current steam flow rate of the low-pressure cylinder to the controller; The controller compares the current low-pressure cylinder steam flow rate with the preset low-pressure cylinder steam flow rate. If the current low-pressure cylinder steam flow rate is higher than the preset low-pressure cylinder steam flow rate, a vacuum pressure value matching the preset low-pressure cylinder steam flow rate is obtained as the matching vacuum pressure value. Based on the pressure value of the second steam path and the matching vacuum pressure value, the controller obtains the pressure adjustment value of the cold steam with the fourth temperature discharged by the main control vortex tube and the pressure adjustment value of the cold steam with the fourth temperature discharged by each controlled vortex tube. The controller then sends the pressure adjustment value of the cold steam with the fourth temperature discharged by each controlled vortex tube to the transceiver of each controlled vortex tube. The main control vortex tube discharges the cold steam with the fourth temperature according to the pressure adjustment value of the cold steam with the fourth temperature discharged by the main control vortex tube. Each controlled vortex tube discharges the cold steam at the fourth temperature according to the pressure adjustment value provided by the controller.

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