A dense-phase carbon dioxide storage tank device and a circulating power system

Abstract

The present invention discloses a dense-phase carbon dioxide storage tank device, which includes a storage tank body; the storage tank body is placed in an inclined horizontal position, and a drainage pipe section and an outlet mesh section are both arranged inside the tank body; one end of the drainage pipe section extends towards the outer side of the upper end of the storage tank body and is connected to an inlet pipe section; the other end of the drainage pipe section extends into the interior of the storage tank body and extends towards the bottom of the lower end of the storage tank body; one end of the outlet mesh section extends into the interior of the storage tank body, and the other end extends towards the outer side of the lower end of the storage tank body and is connected to an outlet pipe section; a flow-blocking and temperature-uniforming plate is uniformly arranged inside the storage tank body, and a plurality of through-flow holes are opened on the flow-blocking and temperature-uniforming plate; the flow-blocking and temperature-uniforming plate has a preset thermal conductivity and is used to uniformly the temperature difference in a preset area inside the storage tank body; the present invention reduces the fluid kinetic energy loss generated by the impact of the fluid in the tank, reduces the temperature and pressure fluctuations and irreversible losses generated by the shaking in the tank, and effectively avoids the phenomenon of uneven temperature distribution in the tank.

Description

Technical Field

[0001] The invention belongs to the technical field of supercritical carbon dioxide Brayton cycle power system, and in particular relates to a dense phase carbon dioxide storage tank device and a cycle power system. Background Art

[0002] Supercritical carbon dioxide (SCO2) is a carbon dioxide fluid maintained above the critical temperature and critical pressure, with the characteristics of high density and low viscosity; when the temperature of carbon dioxide is lower than the critical temperature or when the pressure of carbon dioxide is higher than the critical pressure, it will be in a subcritical state or liquid phase state depending on the temperature, and the overall density is relatively high; carbon dioxide in the subcritical state or liquid phase state and supercritical carbon dioxide are collectively called dense phase carbon dioxide.

[0003] The supercritical carbon dioxide Brayton cycle power system has the advantages of fewer system components, compact equipment size, high system output power density, and higher system cycle efficiency than the steam Rankine cycle system at medium and high temperature levels. It has great potential in ship power systems, gas waste heat power generation systems and mobile power generation systems. Dense phase carbon dioxide is the main circulating working fluid of the supercritical carbon dioxide Brayton cycle power system, and its storage tank is one of the important components of the cycle power system. The carbon dioxide storage tank is used to charge carbon dioxide before the cycle power system is started and to store carbon dioxide when the cycle power system is shut down. At present, carbon dioxide storage tanks are generally used to store supercritical carbon dioxide of a preset quality to support the startup of the cycle power system and the dynamic characteristics of the adjustment system, to ensure that the downstream power equipment is in the best operating state, and to meet the multi-modal output and power rapid switching requirements of the cycle power system.

[0004] In the application of supercritical carbon dioxide Brayton cycle power system, during the movement of ships or other movable equipment, the frequent acceleration, deceleration and shaking process causes carbon dioxide to produce multi-dimensional accelerated motion, resulting in frequent impact of carbon dioxide on carbon dioxide storage tanks; secondly, since the thermal physical properties of supercritical carbon dioxide change with the coupled change of working fluid temperature and pressure, the energy consumption generated by the shaking impact of carbon dioxide will cause complex changes in the pressure and temperature of the working fluid in the storage tank, causing interface stratification of temperature and pressure, and at the same time generating more complex secondary flow processes, and even leading to the generation of phase change processes, which increases the control difficulty of the cycle power system and increases the operating risks of storage tanks and downstream equipment.

[0005] When facing the start-stop of a supercritical carbon dioxide Brayton cycle power system and its output in multiple power modes, the inlet and outlet flows of existing carbon dioxide storage tanks will change significantly. Specifically, when the cycle power system starts or operates at an increasing power, the inlet flow of the storage tank decreases and the outlet flow increases; when the cycle power system shuts down or operates at a decreasing power, the inlet flow of the storage tank increases and the outlet flow decreases; when an emergency condition occurs in the turbine of the cycle power system, the storage tank needs to provide carbon dioxide in a steady state to downstream equipment to adapt to the wide-range change regulation of the carbon dioxide flow within the cycle power system. Currently, in all existing public contributions, the applicability to a mobile cycle power system has not been considered. For example, in the Chinese patent application "Supercritical carbon dioxide low-pressure storage tank device with anti-phase change and low pressure loss and control method" (application number: CN201810588735.9), for a supercritical carbon dioxide cycle system, a supercritical carbon dioxide storage tank with anti-phase change and low pressure loss is proposed, which is mainly used to reduce the pressure loss of carbon dioxide flowing into the storage tank and prevent the working medium from cooling and liquefying, but does not consider the applicability to a mobile cycle power system. In the Chinese patent application "A carbon dioxide storage tank for supercritical extraction" (application number: CN201620421667.3), a carbon dioxide storage tank for supercritical extraction is proposed, which is mainly used for the storage and transportation of low-pressure gaseous carbon dioxide and is not applicable to high-pressure dense-phase supercritical carbon dioxide.

[0006] In summary, under the conditions applicable to mobile application scenarios, the existing carbon dioxide storage tanks have the following problems: (1) When the storage tank operates in the cycle power system, three-dimensional large-scale vortices or shaking oscillations are generated, which easily cause high pressure loss and temperature rise in the tank body, seriously affecting the stable, safe and reliable operation of the cycle power system; (2) When the flow rate in the cycle power system changes significantly, the accumulation / withdrawal of the working medium in the storage tank will cause obvious pressure changes, resulting in instantaneous fluctuations of the pressure and temperature parameters in the overall storage tank exceeding the allowable values, increasing the control difficulty of the cycle power system or even causing safety accidents; (3) During the start-stop or large-scale operating condition change process of the cycle power system, the temperature, pressure and flow rate of the working medium in the system will change within a wide range. Using the existing storage tank device cannot eliminate the influence of the pressure and the change of the working medium volume caused by the change of the physical properties of the working medium, which will seriously affect the stable operation of downstream equipment. Summary of the Invention

[0007] Aiming at the technical problems existing in the prior art, the present invention provides a dense-phase carbon dioxide storage tank device and a cycle power system, which can reduce the disturbance of high-speed flowing carbon dioxide to the working medium in the storage tank and reduce the internal energy consumption generated by the shaking of supercritical carbon dioxide, so as to ensure the stable, safe and reliable operation of the cycle power system.

[0008] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0009] The present invention provides a dense-phase carbon dioxide storage tank device, which includes a storage tank body, an inlet pipe section, a diversion pipe section, an outlet mesh section, an outlet pipe section and a flow-blocking and temperature-uniforming plate;

[0010] The storage tank body is placed in an inclined horizontal position, and the diversion pipe section and the outlet mesh section are both arranged inside the storage tank body; wherein, one end of the diversion pipe section extends towards the outer side of the upper end of the storage tank body and is connected to the inlet pipe section; the other end of the diversion pipe section extends into the interior of the storage tank body and extends towards the bottom of the lower end of the storage tank body; one end of the outlet mesh section extends into the interior of the storage tank body; the other end of the outlet mesh section extends towards the outer side of the lower end of the storage tank body and is connected to the outlet pipe section;

[0011] The flow-blocking and temperature-uniforming plate is uniformly arranged inside the storage tank body, and the periphery of the flow-blocking and temperature-uniforming plate is connected to the inner wall of the storage tank body; a plurality of flow-through holes are formed on the flow-blocking and temperature-uniforming plate; the flow-blocking and temperature-uniforming plate has a preset heat conduction coefficient for equalizing the temperature difference in a preset area inside the storage tank body.

[0012] Further, an upper through hole is formed at the upper end of the storage tank body, and an inlet four-way structure is hermetically arranged at the upper through hole; wherein, the first port of the inlet four-way structure is connected to the diversion pipe section, and the second port of the inlet four-way structure is connected to the inlet pipe section; the third port of the inlet four-way structure is arranged in two paths, one path is a gas detection and discharge branch, and the other path is a pressure relief branch; wherein, a safety valve is arranged on the pressure relief branch; the fourth port of the inlet four-way structure is used as a working medium filling injection port.

[0013] Further, a lower through hole is formed at the lower end of the storage tank body, and an outlet three-way structure is arranged at the lower through hole; wherein, the first port of the outlet three-way structure is connected to the outlet mesh section, and the second port of the outlet three-way structure is connected to the outlet pipe section; the third port of the outlet three-way structure is arranged in two paths, one path is a temperature monitoring branch, and the other path is a pressure monitoring branch; wherein, a temperature sensor is arranged on the temperature monitoring branch, and a pressure sensor is arranged on the pressure monitoring branch.

[0014] Further, the diversion pipe section includes a starting pipe section, a transition pipe section and an end pipe section which are connected in sequence;

[0015] Wherein, the center line of the starting pipe section coincides with the central axis of the storage tank body, and the transition pipe section is a smooth transition pipe section; the center line of the end pipe section is parallel to the axis of the storage tank body and is arranged close to one side of the bottom of the side wall of the storage tank body.

[0016] Further, the end of the end pipe section is an inclined cut, and the opening direction of the inclined cut is set towards the lower center side of the storage tank body; circular openings are evenly arranged on the side wall of the end pipe section.

[0017] Further, it further includes an electric heater and a control module; the electric heater is arranged inside the storage tank body and is close to the end of the diversion pipe section; the control end of the electric heater is connected to the output end of the control module; the control module is used to control the start and stop of the electric heater according to the internal temperature data and internal pressure data of the storage tank body.

[0018] Further, the storage tank body adopts a closed cylindrical structure, and the storage tank body includes a metal inner liner layer, a carbon fiber winding layer, a heating tape layer, a heat insulation layer and a heat insulation shell layer which are arranged in sequence from inside to outside.

[0019] Further, the flow blocking and temperature equalizing plate includes a first flow blocking and temperature equalizing plate, a second flow blocking and temperature equalizing plate and a third flow blocking and temperature equalizing plate;

[0020] The first flow blocking and temperature equalizing plate is arranged at intervals along the central axis of the storage tank body, and the first flow blocking and temperature equalizing plate is perpendicular to the central axis of the storage tank body;

[0021] The second flow blocking and temperature equalizing plate is perpendicular to the third flow blocking and temperature equalizing plate and is arranged along the entire length of the central axis of the storage tank body; wherein, the third flow blocking and temperature equalizing plate is arranged vertically.

[0022] Further, the outlet mesh section adopts a reduced diameter structure; the outlet mesh section includes a reduced diameter metal outer layer and a metal mesh structure, and the metal mesh structure is arranged inside the reduced diameter metal outer layer.

[0023] The present invention also provides a circulating power system, and the circulating power system is a supercritical carbon dioxide Brayton cycle power system, which includes a main storage tank, a sub-storage tank, a first one-way valve, a second one-way valve, a flow meter and a system main body;

[0024] The carbon dioxide outlet of the system main body is arranged in two paths, one path is connected to the first end of the first one-way valve, and the other path is connected to the inlet end of the main storage tank; the second end of the first one-way valve is connected to the inlet end of the sub-storage tank, and the outlet end of the sub-storage tank is connected to the first end of the second one-way valve;

[0025] The outlet end of the main storage tank, the second end of the second one-way valve and the first end of the flow meter are all connected, and the second end of the flow meter is connected to the carbon dioxide inlet of the system main body; wherein, the main storage tank and the sub-storage tank have the same structure and both adopt the above-mentioned one kind of dense-phase carbon dioxide storage tank device.

[0026] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0027] The present invention provides a dense-phase carbon dioxide storage tank device and a circulating power system. A drainage pipe section is arranged inside the storage tank body and extends to the lower bottom area of the storage tank body. The high-speed working fluid is drained to the lower outlet area of the storage tank body by using the drainage pipe section, so as to reduce the loss of fluid kinetic energy generated by the impact of the fluid in the tank, and effectively improve the stability of carbon dioxide. By arranging a flow-blocking and temperature-equalizing plate inside the storage tank body, and using the damping performance of the flow-blocking and temperature-equalizing plate, the temperature and pressure fluctuations and irreversible losses generated by the shaking in the tank are reduced. At the same time, by using the temperature-equalizing performance of the flow-blocking and temperature-equalizing plate, the phenomenon of uneven temperature distribution in the tank is effectively avoided. Secondly, the storage tank body is arranged in an inclined horizontal position, ensuring high reliability in a frequently vibrating environment, meeting the sufficient liquid supply requirements during the start-stop or emergency conditions of the circulating power system, effectively reducing the probability of working fluid leakage, being applicable to mobile application places, and ensuring the stable, safe and reliable operation of the circulating power system.

[0028] Furthermore, an inlet four-way structure is arranged at the upper through-hole of the storage tank body, and an outlet three-way structure is arranged at the lower through-hole of the storage tank body, reducing the openings on the storage tank body, avoiding the fatigue cracks appearing at the opening welds, and effectively improving the structural strength of the storage tank body.

[0029] Furthermore, the drainage pipe section adopts a structural form of a starting pipe section, a transition pipe section and a terminal pipe section connected in sequence. The starting pipe section enters from the inlet of the storage tank body, is guided to the lower part of the storage tank body through the transition pipe section with a bending structure, and discharges the refluxed fluid from the bottom of the storage tank. The bottom area is a liquid or liquid-phase dense area; during operation, the non-condensable gas or the working fluid with a lighter density accumulated above the storage tank body is prevented from affecting the refluxed fluid.

[0030] Furthermore, the end of the terminal pipe section is set as an inclined cut, so that the flow direction of the fluid will not generate a downward flow due to the fluctuations in the pipe, and can only flow upward to the outlet direction; circular openings are evenly arranged on the side wall of the terminal pipe section. If non-condensable gas or a small amount of vaporized carbon dioxide gas is generated during the long-term working process, it can be discharged to the top of the storage tank through the circular openings evenly arranged on the side wall, and will not accumulate in the guiding pipe, avoiding the increase of the reflux resistance.

[0031] Furthermore, by setting an electric heater and a control module, it can be realized to keep the working fluid in the tank above the supercritical condition, and ensure sufficient liquid supply and stable working condition parameters during emergency conditions.

[0032] Furthermore, the storage tank body includes a metal inner liner layer, a carbon fiber winding layer, a heating tape layer, a thermal insulation layer, and a thermal insulation shell layer arranged in sequence from inside to outside. By using a metal material as the substrate and carbon fiber as the tank body material, it has the characteristics of light weight, high pressure and temperature resistance, and high safety, meeting the application requirements in mobile scenarios.

[0033] Furthermore, a parallel setting method of a main storage tank and a secondary storage tank is adopted. By adjusting the temperature and pressure parameters of the secondary storage tank, it is ensured that the parameters of the circulating power system can be adjusted within a wide range. Brief Description of the Drawings

[0034] Figure 1 It is a schematic diagram of the overall structure of the dense-phase carbon dioxide storage tank device described in Embodiment 1;

[0035] Figure 2 It is a schematic cross-sectional view of the storage tank body in Embodiment 1;

[0036] Figure 3 It is a schematic diagram of the structure of the first flow-blocking and temperature-equalizing baffle in Embodiment 1;

[0037] Figure 4 It is a schematic diagram of the layout positions of the second flow-blocking and temperature-equalizing baffle and the third flow-blocking and temperature-equalizing baffle in Embodiment 1;

[0038] Figure 5 It is a structural block diagram of the circulating power system described in Embodiment 2.

[0039] Wherein, 1 is the storage tank body, 2 is the inlet pipe section, 3 is the diversion pipe section, 4 is the outlet mesh section, 5 is the outlet pipe section, 6 is the first flow-blocking and temperature-equalizing plate, 7 is the second flow-blocking and temperature-equalizing plate, 8 is the third flow-blocking and temperature-equalizing plate, 9 is the inlet four-way structure, 10 is the outlet three-way structure, 11 is the gas discharge branch, 12 is the safety valve, 13 is the working medium filling inlet, 14 is the temperature sensor, 15 is the pressure sensor, 16 is the electric heater, 17 is the shock-absorbing fixing bracket; 101 is the metal inner liner layer, 102 is the carbon fiber winding layer, 103 is the heating tape layer, 104 is the thermal insulation layer, 105 is the protective shell layer; 301 is the starting pipe section, 302 is the transition pipe section, 303 is the end pipe section, 304 is the circular opening; 601 is the through-flow hole, 602 is the diversion pipe through-hole; 100 is the main storage tank, 200 is the secondary storage tank, 300 is the first one-way valve, 400 is the second one-way valve, 500 is the flowmeter, 600 is the system main body. Detailed Embodiments

[0040] In order to make the technical problems, technical solutions, and beneficial effects solved by the present invention clearer and more understandable, the following specific embodiments are used to further elaborate on the present invention. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0041] Embodiment 1

[0042] As shown in the appendix Figures 1-4 As shown, Embodiment 1 provides a dense-phase carbon dioxide storage tank device, including a storage tank body 1, an inlet pipe section 2, a diversion pipe section 3, an outlet mesh section 4, an outlet pipe section 5, a flow-blocking and temperature-equalizing plate, an inlet four-way structure 9, an outlet three-way structure 10, a safety valve 12, a temperature sensor 14, a pressure sensor 15, an electric heater 16, a shock-absorbing and fixing bracket 17, and a control module.

[0043] The storage tank body 1 stores dense-phase carbon dioxide. The storage tank body 1 is a closed cylindrical structure and is a multi-layer wrapped structure. The storage tank body 1 includes a metal inner tank layer 101, a carbon fiber winding layer 102, a heating tape layer 103, a heat insulation layer 104, and a heat insulation shell layer 105 arranged in sequence from the inside to the outside. The storage tank body 1 is placed in an inclined horizontal position and fixed on the shock-absorbing and fixing bracket 17. Preferably, the included angle between the central axis of the storage tank body 1 and the horizontal plane is 15°. An upper through hole is opened at the upper end of the storage tank body 1, and the upper through hole is located at the center of the upper end of the storage tank body 1. A lower through hole is opened at the lower end of the storage tank body 1, and the lower through hole is located at the center of the lower end of the storage tank body 1. The metal inner tank layer 101 is made of aluminum alloy material, and the carbon fiber winding layer 102 is made by evenly winding carbon fiber material on the outside of the metal inner tank layer 101. The heating tape layer 103 is made in the form of evenly arranging heating tapes on the outside of the carbon fiber winding layer 102. The heat insulation shell layer 105 is an aluminum shell structure wrapped outside the heat insulation layer 104.

[0044] The diversion pipe section 3 is arranged inside the storage tank body 1 and is arranged close to one side of the upper end of the storage tank body 1. Among them, one end of the diversion pipe section 3 extends towards the outside of the upper end of the storage tank body 1. The other end of the diversion pipe section 3 extends into the interior of the storage tank body 1 and extends towards the bottom of the lower end of the storage tank body 1. The diversion pipe section 3 includes a starting pipe section 301, a transition pipe section 302, and an end pipe section 303 connected in sequence. The central axis of the starting pipe section 301 coincides with the central axis of the storage tank body 1. The transition pipe section 302 is a smooth transition pipe section. The central axis of the end pipe section 303 is parallel to the axis of the storage tank body 1 and is arranged close to one side of the bottom of the side wall of the storage tank body 1.

[0045] Specifically, the first end of the starting pipe section 301 extends towards the outer side of the upper end of the storage tank body 1, and the second end of the starting pipe section 301 extends into the interior of the storage tank body 1 along the central axis of the storage tank body 1; one end of the transition pipe section 302 is connected to the second end of the starting pipe section 301, and the other end of the transition pipe section 302 is connected to the first end of the end pipe section 303; the second end of the end pipe section 303 extends along the bottom of the side wall of the storage tank body 1 and towards the lower end of the storage tank body 1; wherein, the end of the second end of the end pipe section 303 is an inclined cut, the opening direction of the inclined cut is set towards the center side of the lower end of the storage tank body 1, and circular openings 304 are evenly arranged on the outer side of the end pipe section 303.

[0046] The inlet four-way structure 9 is hermetically arranged at the upper through-hole, and there are four ports on the inlet four-way structure 9; wherein, the inlet four-way structure 9 and the upper through-hole are connected by means of a conical sealing surface; the first port of the inlet four-way structure 9 is connected to the first end of the starting pipe section 301; wherein, the inlet four-way structure 9 and the starting pipe section 301 are connected by means of a high-pressure resistant ferrule joint; the second port of the inlet four-way structure 9 is connected to the inlet pipe section 2; the third port of the inlet four-way structure 9 is arranged in two paths, one path is a gas detection and discharge branch 11, and the other path is a pressure relief branch; wherein, a gas detection instrument is arranged on the gas detection and discharge branch 11, and a safety valve 12 is arranged on the pressure relief branch; the fourth port of the inlet four-way structure 9 serves as a working medium filling injection port 13.

[0047] The outlet mesh section 4 is arranged inside the storage tank body 1 and is arranged close to one side of the lower end of the storage tank body 1; wherein, the first end of the outlet mesh section 4 extends into the interior of the storage tank body 1, and the second end of the outlet mesh section 4 extends towards the outer side of the lower end of the storage tank body 1; the outlet mesh section 4 adopts a reduced diameter structure, including a reduced diameter metal layer and a metal mesh structure, and the metal mesh structure is arranged inside the reduced diameter metal layer.

[0048] The outlet three-way structure 10 is hermetically arranged at the lower through-hole, and three ports are arranged on the outlet three-way structure 10; wherein, the outlet three-way structure 10 and the lower through-hole are connected by means of a conical sealing surface; specifically, the first port of the outlet three-way structure 10 is connected to the second end of the outlet mesh section 4, and the second port of the outlet three-way structure 10 is connected to the outlet pipe section 5; the third port of the outlet three-way structure 10 is arranged in two paths, one path is a temperature monitoring branch, and the other path is a pressure monitoring branch; wherein, a temperature sensor 14 is arranged on the temperature monitoring branch, and a pressure sensor 15 is arranged on the pressure monitoring branch; wherein, the temperature sensor 14 is used to collect the internal temperature data of the storage tank body 1; the pressure sensor 15 is used to collect the internal pressure data of the storage tank body 1.

[0049] The flow-blocking and temperature-uniforming plate is arranged in the storage tank body 1, and the periphery of the flow-blocking and temperature-uniforming plate is connected to the inner wall of the storage tank body 1; a plurality of through-flow holes 601 are formed in the flow-blocking and temperature-uniforming plate, which has good damping performance; meanwhile, the flow-blocking and temperature-uniforming plate has a preset heat conduction coefficient and is used to equalize the temperature difference between the inside of the storage tank body 1 and a preset area; the flow-blocking and temperature-uniforming plate is a porous aluminum plate-like structure, and the periphery of the flow-blocking and temperature-uniforming plate is fixedly connected to the metal inner single layer 101; wherein, a drainage pipe through-hole 602 is also formed in the flow-blocking and temperature-uniforming plate for the drainage pipe section 3 to pass through.

[0050] Specifically, the flow-blocking and temperature-uniforming plate includes a first flow-blocking and temperature-uniforming plate 6, a second flow-blocking and temperature-uniforming plate 7 and a third flow-blocking and temperature-uniforming plate 8; the first flow-blocking and temperature-uniforming plate 6 is arranged at intervals along the central axis of the storage tank body 1, and the first flow-blocking and temperature-uniforming plate 6 is perpendicular to the central axis of the storage tank body 1; the second flow-blocking and temperature-uniforming plate 7 is perpendicular to the third flow-blocking and temperature-uniforming plate 8 and is arranged along the entire length of the central axis of the storage tank body 1; wherein, the third flow-blocking and temperature-uniforming plate 8 is arranged vertically.

[0051] The electric heater 16 is arranged inside the storage tank body 1 and is arranged near the end of the drainage pipe section 3; the output end of the temperature sensor 14 is connected to the first input end of the control module, the output end of the pressure sensor 15 is connected to the second input end of the control module, the control end of the electric heater 16 is connected to the first output end of the control module, and the second output end of the control module is connected to the control end of the heat tracing layer 103; the control module is used to control the start and stop of the heat tracing layer 103 or the electric heater 16 according to the internal temperature data and internal pressure data of the storage tank body 1; wherein, the heat tracing layer 103 is used to heat the internal environment of the storage tank body 1; the electric heater 16 is used to heat a local area at the end of the drainage pipe section 3.

[0052] Working principle:

[0053] For the dense-phase carbon dioxide storage tank device described in Embodiment 1, during operation, the mainstream fluid flows successively through the inlet pipe section 2, the inlet four-way structure 9, the diversion pipe section 3, the outlet mesh section 4, the outlet three-way structure 10, and the outlet pipe section 6; among them, the mainstream working fluid comes into contact with and exchanges kinetic energy with a small part of the dense-phase carbon dioxide in the storage tank body 1, effectively ensuring that the irreversible loss of the dense-phase carbon dioxide in the storage tank body due to flow circulation is small.

[0054] In Embodiment 1, a gas detection and discharge branch 11 and a pressure relief branch are provided on the inlet four-way structure 9, and a safety valve 12 is provided on the pressure relief branch; a temperature sensor 14 and a pressure sensor 15 are provided on the outlet three-way structure 10; when the pressure of the dense-phase carbon dioxide in the storage tank body 1 does not exceed the maximum allowable pressure, the safety valve 12 does not work; when the pressure of the dense-phase carbon dioxide in the tank body 1 exceeds the maximum allowable pressure, the safety valve 12 works to discharge the gas working medium; a gas detection instrument is provided on the gas detection and discharge branch 11, and the gas detection instrument is used to detect the non-condensable gas in the storage tank body 1; when the non-condensable gas reaches the maximum allowable value, the gas detection and discharge branch 11 is opened to discharge the non-condensable gas to the outside; secondly, when the internal pressure of the storage tank body 1 exceeds the preset threshold and active discharge of the working medium is required, the gas detection and discharge branch 11 is actively opened to enable the working medium to be actively discharged.

[0055] In Embodiment 1, when the dense-phase carbon dioxide in the storage tank body 1 flows normally, the standard temperature of the working medium in the storage tank body 1 is set as the critical temperature, and the standard pressure of the working medium in the storage tank body 1 is set as the critical pressure; among them, the critical temperature is 31 °C and the critical pressure is 7.4 MPa; using the control module, according to the internal temperature data collected by the temperature sensor 14 and the internal pressure data collected by the pressure sensor 15, to control the start and stop of the heating tape layer 103 and the electric heater 16; specifically, when the internal temperature in the storage tank body 1 is less than the critical temperature and the internal pressure is lower than the critical pressure, the control module is used to control the heating tape layer 103 to turn on to heat the internal space of the storage tank body 1 until the internal temperature of the storage tank body 1 is greater than the critical temperature and the internal pressure is greater than the critical pressure; then, the control module controls the heating tape layer 103 to shut down; when the dense-phase carbon dioxide in the storage tank body 1 is insufficient, that is, when the internal temperature of the storage tank body 1 reaches the critical temperature but the internal pressure is lower than the critical pressure, dense-phase carbon dioxide is supplemented into the interior of the storage tank body 1 through the working medium filling injection port 13.

[0056] When an emergency condition occurs during the operation of the circulating power system, the circulating power system needs to continuously supply cooling working medium to the downstream through the compressor, that is, when the carbon dioxide flow rate in the inlet pipe 2 decreases and the carbon dioxide flow rate in the outlet pipe section 5 remains unchanged or increases, the internal pressure of the storage tank body 1 will gradually decrease. Since the Joule-Thomson coefficient of dense-phase carbon dioxide is positive, the larger the value of the Joule-Thomson coefficient is when the temperature is lower. Therefore, when the internal pressure of the storage tank body 1 further decreases, the temperature of the dense-phase carbon dioxide also does not decrease; since the decrease in temperature causes the density of the dense-phase carbon dioxide to further increase, the internal pressure of the storage tank body 1 further decreases; among them, the emergency condition is, for example, the downstream turbine stops or a break accident occurs downstream; when the control unit of the circulating power system obtains an emergency condition signal sent by the system, and at the same time the internal temperature of the storage tank body 1 collected by the temperature sensor 14 is lower than the critical temperature and the internal pressure of the storage tank body 1 collected by the pressure sensor 15 is lower than the critical pressure, at this time, the heating tape layer 103 is started to heat the storage tank body 1 and the temperature of the dense-phase carbon dioxide inside to prevent frosting or dry ice formation at the inlet and outlet of the storage tank body 1; at the same time, the electric heater 16 is turned on to gasify the carbon dioxide in the diversion pipe section 3, maintain the system pressure at the critical pressure, and ensure that the carbon dioxide in the outlet pipe section 5 is in a dense phase state.

[0057] For the dense-phase carbon dioxide storage tank device of the present invention, the storage tank body adopts a multi-layer wrapping structure, and a tank body structure is formed by sequentially arranging a metal inner tank layer, a carbon fiber winding layer, a heating tape layer, a heat insulation layer and a heat insulation shell layer from the inside to the outside, greatly reducing the mass of the tank body; by arranging a diversion pipe section and an outlet mesh section in the storage tank body, the disturbance of the high-speed flowing carbon dioxide to the working medium in the tank body is reduced; by arranging a flow resistance and temperature equalizing plate in the tank body, the internal energy consumption generated by the shaking of the dense-phase carbon dioxide is reduced and the temperature of the fluid is made uniform; by placing the storage tank body in an inclined horizontal position on the shock-absorbing fixed support, it is ensured that the carbon dioxide liquid discharged from the storage tank body is in a liquid or supercritical state; by setting a safety valve, a pressure sensor, a temperature sensor and a control module, the functions of storing, detecting the temperature and pressure, discharging overpressure, quickly emptying, preventing phase change and drastic fluctuation of the thermal properties of the dense-phase carbon dioxide are realized.

[0058] Embodiment 2

[0059] This Embodiment 2 provides a circulating power system, and the circulating power system is a supercritical carbon dioxide Brayton cycle power system; as shown in the attached Figure 5 figure, the circulating power system includes a main storage tank 100, a secondary storage tank 200, a first one-way valve 300, a second one-way valve 400, a flow meter 500 and a system main body 600.

[0060] In this Embodiment 2, the carbon dioxide outlet of the system main body 600 is provided in two paths, one of which is connected to the first end of the first one-way valve 300, and the other is connected to the inlet end of the main storage tank 100; the second end of the first one-way valve 300 is connected to the inlet end of the auxiliary storage tank 200, and the outlet end of the auxiliary storage tank 200 is connected to the first end of the second one-way valve 400; the outlet end of the main storage tank 100, the second end of the second one-way valve 400 and the first end of the flowmeter 500 are all connected, and the second end of the flowmeter 500 is connected to the carbon dioxide inlet of the system main body 600; wherein, the main storage tank 100 and the auxiliary storage tank 200 have the same structure, and both adopt a dense-phase carbon dioxide storage tank device described in the above Embodiment 1.

[0061] Working principle:

[0062] For the circulating power system of the present invention, by providing two main storage tanks 100 and auxiliary storage tanks 200 with the same structure, and distributing the first one-way valve 300 and the second one-way valve 400 at the inlet and outlet of the auxiliary storage tank 200; when the system starts or runs at increased power, the temperature and pressure of the carbon dioxide in the system increase, resulting in the volume expansion of the carbon dioxide working medium. During the process of the excess carbon dioxide returning to the main storage tank 100, part of the carbon dioxide enters the auxiliary storage tank 200 through the first one-way valve 300. When it is detected that the flow data of the flowmeter 500 is no longer increasing and the internal temperature and internal pressure of the auxiliary storage tank 200 are close to being stable, by controlling the heat tracing layer 103 and the electric heater 16 of the auxiliary storage tank 200 to be turned on to vaporize the carbon dioxide in the auxiliary storage tank, thereby maintaining the pressure of the working medium in the auxiliary storage tank 200 at the critical pressure; when the system shuts down or runs at reduced power, the temperature and pressure of the carbon dioxide in the system decrease, resulting in the reduction of the carbon dioxide volume. By controlling the heat tracing layer 103 and the electric heater 16 of the auxiliary storage tank 200 to be turned on to vaporize the carbon dioxide, so as to maintain the pressure of the working medium in the auxiliary storage tank 200 at 7.4 - 8.0 MPa, and then supplement the carbon dioxide in the auxiliary storage tank into the system main body 600; when it is detected that the flow data of the flowmeter 500 is no longer decreasing, stop the heat tracing layer 13 and the electric heater 16, so that the carbon dioxide pressure in the auxiliary storage tank 29 finally equals the internal pressure of the main storage tank 300.

[0063] The dense-phase carbon dioxide storage tank device and the circulation power system according to the present invention are provided with an inlet four-way structure and an outlet three-way structure at the upper and lower ends of the storage tank body respectively; wherein, a high-pressure-resistant threaded connection is adopted between the inlet four-way structure or the outlet three-way structure and the storage tank body, and a conical sealing surface is used for the sealing connection; the inlet four-way structure is used to connect the diversion pipe section and the inlet pipe section, and the outlet three-way structure is used to connect the outlet mesh section and the outlet pipe section; wherein, a high-pressure-resistant ferrule interface is adopted for the connection between the inlet four-way structure and the diversion pipe section; in addition, a gas monitoring and discharge branch, a pressure relief branch and a main working medium filling inlet are also arranged on the inlet four-way structure; wherein, a safety valve is arranged on the pressure relief branch; a temperature monitoring branch and a pressure monitoring branch are also arranged on the outlet three-way structure; wherein, a temperature sensor is arranged on the temperature monitoring branch, and a pressure sensor is arranged on the pressure monitoring branch.

[0064] In the present invention, the storage tank body adopts a cylindrical barrel structure, and the outlet of the diversion pipe section is arranged at the bottom of the lower end of the storage tank body; the end outlet of the diversion pipe section is in the form of an inclined cut, and a plurality of circular openings 304 are arranged on the side wall of its end pipe section to ensure the stability of the outflow process of the working medium; the control end of the heating tape layer is connected to the control module, and the control module can control the start and stop of the heating tape layer according to the data collected by the temperature sensor and the pressure sensor.

[0065] In the present invention, a first flow-blocking and temperature-uniforming plate, a second flow-blocking and temperature-uniforming plate and a third flow-blocking and temperature-uniforming plate are respectively arranged inside the storage tank body along three different directions, and a plurality of through-flow holes are arranged on the flow-blocking and temperature-uniforming plates. The through-flow holes play a role in connecting the fluids on both sides, so that it has good damping performance; the flow-blocking and temperature-uniforming plates have a preset heat conduction coefficient to realize the temperature difference uniformity of each part area inside the storage tank body; a diversion pipe through-hole is arranged on the flow-blocking and temperature-uniforming plates to play a role in fixing the diversion pipe section while allowing the diversion pipe section to pass through.

[0066] The dense-phase carbon dioxide storage tank device and the circulation power system described in the present invention realize the filling, working medium storage, working medium transportation, overpressure and non-condensable gas discharge of dense-phase carbon dioxide, as well as the stable control of the temperature and pressure of the working medium; by using aluminum as the lining substrate of the metal inner tank layer and carbon fiber winding layer as the tank body material, it has the characteristics of light weight and high safety; the pressure and temperature resistance performance of the storage tank body is much higher than the critical pressure and critical temperature of supercritical carbon dioxide, meeting the application requirements in mobile scenarios; in the present invention, by arranging a drainage pipe section in the storage tank body, the drainage pipe section is used to guide the high-speed fluid to the bottom area of the liquid outlet of the storage tank body, reducing the loss of fluid kinetic energy generated by the impact of the fluid in the pipe and improving the stability of the working medium; in the present invention, by adding a flow-blocking and temperature-uniforming plate in the storage tank body, the temperature and pressure fluctuations and irreversible losses generated by the shaking in the tank are reduced. At the same time, the flow-blocking and temperature-uniforming plate has good temperature-uniforming performance, which can solve the problem of uneven temperature distribution in the tank; in the present invention, there are no redundant openings on the storage tank body, and the storage tank body is placed obliquely and horizontally on the shock-absorbing fixing frame, ensuring high reliability of the storage tank body in a frequent vibration environment, sufficient liquid supply during start-stop and emergency conditions, and lower leakage probability.

[0067] In the present invention, by setting a temperature sensor, a pressure sensor, a heat tracing layer, an electric heater and a control module, it is possible to keep the working medium in the tank above the supercritical condition and ensure sufficient liquid supply and stable working condition parameters during emergency conditions; secondly, by setting a gas detection and discharge branch and a pressure relief branch at the inlet, the storage tank body has the functions of overpressure automatic pressure relief protection and non-condensable gas discharge; in the circulation power system, a combination form of a main storage tank and a secondary storage tank is adopted, and by adjusting the temperature and pressure parameters of the secondary storage tank, it is ensured that the system parameters can be adjusted within a wide range.

[0068] The dense-phase carbon dioxide storage tank device and the circulation power system described in the present invention can stably store and conveniently provide carbon dioxide with stable temperature and pressure to downstream equipment; realize automatic control of the temperature and pressure parameters of the working medium in the storage tank to be stable at the set value; at the same time, it can detect the gas state, and is convenient to carry and transport, with the characteristics of small volume and light weight, effectively reducing the problems of the volume and weight of the supercritical carbon dioxide storage tank, the pressure loss of the working medium, the phase change of the working medium, and the uneven heat distribution.

[0069] The above embodiments are only one of the implementation manners that can realize the technical solution of the present invention. The scope of protection required by the present invention is not only limited by this embodiment, but also includes any changes, substitutions and other implementation manners that are easily conceivable by those skilled in the art within the technical scope disclosed by the present invention.

Claims

1. A dense-phase carbon dioxide storage tank device, characterized in that, It includes a storage tank body (1), an inlet pipe section (2), a drainage pipe section (3), an outlet mesh section (4), an outlet pipe section (5) and a flow-blocking and temperature-uniforming plate; The storage tank body (1) is placed in an inclined horizontal position. The drainage pipe section (3) and the outlet mesh section (4) are both arranged inside the storage tank body (1). Among them, one end of the drainage pipe section (3) extends towards the outer side of the upper end of the storage tank body (1) and is connected to the inlet pipe section (2). The other end of the drainage pipe section (3) extends into the interior of the storage tank body (1) and extends towards the bottom of the lower end of the storage tank body (1). One end of the outlet mesh section (4) extends into the interior of the storage tank body (1). The other end of the outlet mesh section (4) extends towards the outer side of the lower end of the storage tank body (1) and is connected to the outlet pipe section (5); The flow-blocking and temperature-uniforming plate is evenly arranged inside the storage tank body (1), and the periphery of the flow-blocking and temperature-uniforming plate is connected to the inner wall of the storage tank body (1). A number of through-flow holes are opened on the flow-blocking and temperature-uniforming plate. The flow-blocking and temperature-uniforming plate has a preset thermal conductivity for equalizing the temperature difference in a preset area inside the storage tank body; The drainage pipe section (3) includes a starting pipe section (301), a transition pipe section (302) and a terminal pipe section (303) connected in sequence; Among them, the center line of the starting pipe section (301) coincides with the central axis of the storage tank body (1), and the transition pipe section (302) is a smooth transition pipe section. The center line of the terminal pipe section (303) is parallel to the axis of the storage tank body (1) and is arranged close to one side of the bottom of the side wall of the storage tank body (1); The end of the terminal pipe section (303) is an inclined cut, and the opening direction of the inclined cut is arranged towards one side of the center of the lower end of the storage tank body (1). Circular openings (304) are evenly opened on the side wall of the terminal pipe section (303).

2. The dense-phase carbon dioxide storage tank device according to claim 1, characterized in that, An upper through-hole is opened at the upper end of the storage tank body (1), and an inlet four-way structure (9) is hermetically arranged at the upper through-hole. Among them, the first port of the inlet four-way structure (9) is connected to the drainage pipe section (3), and the second port of the inlet four-way structure (9) is connected to the inlet pipe section (2). The third port of the inlet four-way structure (9) is arranged in two branches. One branch is a gas detection and discharge branch (11), and the other branch is a pressure relief branch. Among them, a safety valve (12) is arranged on the pressure relief branch. The fourth port of the inlet four-way structure (9) serves as a working medium filling injection port (13).

3. The dense-phase carbon dioxide storage tank device according to claim 1, characterized in that, A lower through-hole is formed at the lower end of the storage tank body (1), and an outlet tee structure (10) is arranged at the lower through-hole; wherein, a first port of the outlet tee structure (10) is connected to the outlet mesh section (4), and a second port of the outlet tee structure (10) is connected to the outlet pipe section (5); the third port of the outlet tee structure (10) is arranged in two paths, one path is a temperature monitoring branch, and the other path is a pressure monitoring branch; wherein, a temperature sensor (14) is arranged on the temperature monitoring branch, and a pressure sensor (15) is arranged on the pressure monitoring branch.

4. The dense-phase carbon dioxide storage tank device according to claim 1, characterized in that, It further includes an electric heater (16) and a control module; the electric heater (16) is arranged inside the storage tank body (1) and is close to the end of the diversion pipe section (3); a control end of the electric heater (16) is connected to an output end of the control module; the control module is used to control the start and stop of the electric heater (16) according to the internal temperature data and internal pressure data of the storage tank body (1).

5. The dense-phase carbon dioxide storage tank device according to claim 1, characterized in that, The storage tank body (1) adopts a sealed cylindrical structure, and the storage tank body (1) includes a metal inner liner layer (101), a carbon fiber winding layer (102), a heating tape layer (103), a heat insulation layer (104) and a heat insulation shell layer (105) which are arranged in sequence from inside to outside.

6. The dense-phase carbon dioxide storage tank device according to claim 1, characterized in that, The flow resistance and temperature equalizing plate includes a first flow resistance and temperature equalizing plate (6), a second flow resistance and temperature equalizing plate (7) and a third flow resistance and temperature equalizing plate (8); The first flow resistance and temperature equalizing plate (6) is arranged at intervals along the central axis of the storage tank body (1), and the first flow resistance and temperature equalizing plate (6) is perpendicular to the central axis of the storage tank body (1); The second flow resistance and temperature equalizing plate (7) is perpendicular to the third flow resistance and temperature equalizing plate (8) and is arranged along the entire length of the central axis of the storage tank body (1); wherein, the third flow resistance and temperature equalizing plate (8) is arranged vertically.

7. The dense-phase carbon dioxide storage tank device according to claim 1, characterized in that, The outlet mesh section (4) adopts a reduced diameter structure; the outlet mesh section (4) includes a reduced diameter metal outer layer and a metal mesh structure, and the metal mesh structure is arranged inside the reduced diameter metal outer layer.

8. A cyclic power system, characterized in that, The circulating power system is a supercritical carbon dioxide Brayton cycle power system, which includes a main storage tank (100), a secondary storage tank (200), a first one-way valve (300), a second one-way valve (400), a flow meter (500) and a system main body (600); The carbon dioxide outlet of the system main body (600) is arranged in two paths, one path is connected to a first end of the first one-way valve (300), and the other path is connected to an inlet end of the main storage tank (100); a second end of the first one-way valve (300) is connected to an inlet end of the secondary storage tank (200), and an outlet end of the secondary storage tank (200) is connected to a first end of the second one-way valve (400); The outlet end of the main storage tank (100), the second end of the second one-way valve (400), and the first end of the flowmeter (500) are all connected. The second end of the flowmeter (500) is connected to the carbon dioxide inlet of the system main body (600); wherein, the main storage tank (100) and the auxiliary storage tank (200) have the same structure and both adopt a dense-phase carbon dioxide storage tank device as described in any one of claims 1-7.

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