Liquid hydrocarbon fuel combustion equipment and direct-combustion supercritical carbon dioxide circulation system

Abstract

The invention discloses liquid hydrocarbon fuel combustion equipment and a supercritical carbon dioxide circulation system, the liquid hydrocarbon fuel combustion equipment comprises a nozzle, a combustion chamber and a rotational flow assembly, the rotational flow assembly comprises a first-stage pipe, a second-stage pipe, a first-stage cyclone, a second-stage cyclone and a third-stage cyclone, and the first-stage pipe and the second-stage pipe are both scaling venturi pipes. The supercritical carbon dioxide circulation system comprises fuel supply equipment, pure oxygen supply equipment and a circulation assembly, mixed gas of carbon dioxide and water vapor generated by combustion of the liquid hydrocarbon fuel combustion equipment is circulated through the circulation assembly to obtain high-purity carbon dioxide, and the high-purity carbon dioxide is divided into three paths to flow into a first-stage swirler, a second-stage swirler and a third-stage swirler; the carbon dioxide flowing into the second-stage cyclone is uniformly mixed with oxygen from pure oxygen supply equipment before flowing into the second-stage cyclone. The combustion ignition delay period and the mixing time can be prolonged, a standing vortex high-temperature rapid reaction area is formed, the problem that the combustion speed is low in the concentrated carbon dioxide atmosphere is solved, and the supercritical carbon dioxide circulation efficiency is improved.

Description

Technical Field

[0001] The present application relates to the technical field of supercritical carbon dioxide power generation, and in particular to a liquid hydrocarbon fuel combustion device and a direct-fired supercritical carbon dioxide circulation system. Background Art

[0002] Supercritical carbon dioxide refers to a carbon dioxide fluid with a temperature exceeding 31°C and a pressure exceeding 7.38MPa. The thermal cycle using supercritical carbon dioxide as the circulating working fluid has the characteristics of high efficiency, high power density, wide power coverage range, low vibration and noise, and wide adaptability of heat sources. It has broad application prospects in nuclear power generation, solar thermal power generation, industrial waste heat power generation, ship power generation and propulsion systems, and fossil fuel combustion power generation.

[0003] Among them, the direct-fired supercritical carbon dioxide cycle has the following characteristics: ① The fuel burns in a mixture of supercritical concentrated carbon dioxide and pure oxygen, without NOx emissions; ② The high-purity carbon dioxide separated by the cycle has high pressure and density, which is easy to capture and utilize directly, thereby achieving complete carbon capture; ③ It can achieve higher cycle operation parameters, with a maximum working pressure of 30MPa, a direct-fired combustion chamber temperature of 1800℃, and a turbine inlet temperature of 1100℃, and its theoretical cycle thermal efficiency is higher; ④ Although the system is more complex, such as the large number of auxiliary machines, it has obvious advantages in cycle efficiency and has a more promising application prospect. It has broader application prospects in the fields of clean zero-carbon power generation, AIP (Air Independent Propulsion), zero-carbon ship power, distributed power generation, etc., and has begun to receive increasing attention.

[0004] The existing direct-fired supercritical carbon dioxide circulating combustion system mostly uses gaseous fuels such as natural gas and synthesis gas, but cannot use liquid fuels. Unlike gaseous fuels, liquid fuels are subject to fragmentation, diffusion, phase change and mixture formation, and in direct-fired circulating combustion environments, liquid fuels also have transcritical spray problems.

[0005] Therefore, there is an urgent need to invent a direct-fired supercritical carbon dioxide circulating combustion system suitable for liquid fuels to solve the problem of rapid combustion organization of liquid fuels in an ultra-concentrated supercritical carbon dioxide atmosphere under a low excess oxygen coefficient. Summary of the invention

[0006] The purpose of this application is to provide a liquid hydrocarbon fuel combustion device and a direct-fired supercritical carbon dioxide circulation system, which can achieve rapid combustion of liquid hydrocarbon fuels and meet the development needs of high efficiency and high power density of marine power systems.

[0007] The technical solution provided by the present invention is as follows:

[0008] A liquid hydrocarbon fuel combustion device, suitable for direct-fired supercritical carbon dioxide cyclic combustion of liquid fuel, comprising:

[0009] A nozzle, a combustion chamber and a swirl assembly, wherein the nozzle is used to spray liquid hydrocarbon fuel, and the sprayed liquid hydrocarbon fuel flows through the swirl assembly and then enters the combustion chamber;

[0010] The swirl assembly includes a primary pipe, a secondary pipe, a primary swirler and a secondary swirler, the primary pipe is sleeved on the nozzle and a first flow channel for external fluid to flow into is formed between the primary pipe and the nozzle, the secondary pipe is sleeved on an end of the primary pipe away from the nozzle and a second flow channel for external fluid to flow into is formed between the primary pipe, and the secondary pipe is connected to the combustion chamber;

[0011] The primary cyclone is arranged at the inlet end of the first flow channel so that the fluid flowing into the first flow channel forms a primary gas cyclone, and the secondary cyclone is arranged at the inlet end of the second flow channel so that the fluid flowing into the second flow channel forms a secondary gas cyclone.

[0012] In some embodiments, the cyclone assembly further comprises a tertiary cyclone;

[0013] A fluid inlet for external fluid to flow into is arranged on one side of the combustion chamber facing the secondary pipe, and the tertiary swirler is arranged at the fluid inlet so that the fluid flowing into the combustion chamber through the fluid inlet forms a tertiary gas swirling flow.

[0014] In some embodiments, the nozzle comprises a swirl nozzle.

[0015] In some embodiments, a primary mixing chamber for fluid mixing is formed inside the first tube, and the primary mixing chamber has an axially connected contraction section and an expansion section, and the contraction section is arranged toward the nozzle; and a secondary mixing chamber for fluid mixing is formed inside the second tube, and the secondary mixing chamber has an axially connected contraction section and an expansion section, and the contraction section is arranged toward the first tube.

[0016] In some embodiments, the inner wall of the first-stage tube forms an outwardly convex arc surface toward the central axis of the first-stage tube, the first mixing chamber forms the contraction section at the convex part of the arc surface, and forms the expansion section at the convex part of the arc surface away from the nozzle; and, the inner wall of the second-stage tube forms an outwardly convex arc surface toward the central axis of the second-stage tube, the second mixing chamber forms the contraction section at the convex part of the arc surface, and forms the expansion section at the convex part of the arc surface away from the first-stage tube.

[0017] In some embodiments, both the primary tube and the secondary tube are venturi tubes.

[0018] The present application also provides a direct-fired supercritical carbon dioxide circulation system, comprising:

[0019] A fuel supply device, a pure oxygen supply device, a circulation component, a delivery pipeline, and a liquid hydrocarbon fuel combustion device provided in any of the above embodiments; wherein the swirl component further comprises a tertiary swirler, which is arranged at the fluid inlet of the combustion chamber so that the fluid flowing into the combustion chamber through the fluid inlet forms a tertiary gas swirl;

[0020] The fuel supply device is used to supply liquid hydrocarbon fuel to the nozzle, and the pure oxygen supply device is used to supply oxygen to the second flow channel. The liquid hydrocarbon fuel forms a mixed gas of carbon dioxide and water vapor after combustion. The circulation component is used to receive the mixed gas. The mixed gas is circulated by the circulation component to obtain high-pressure carbon dioxide. The conveying pipeline conveys the circulated high-pressure carbon dioxide to the first cyclone, the second cyclone and the third cyclone respectively, and flows into the first flow channel, the second flow channel and the combustion chamber through the first cyclone, the second cyclone and the third cyclone; wherein the carbon dioxide flowing into the second cyclone is evenly mixed with the oxygen from the pure oxygen supply device before flowing into the second cyclone.

[0021] In some embodiments, the oxygen flow rate supplied by the pure oxygen supply device is smaller than the high-pressure carbon dioxide flow rate delivered by the delivery pipeline to the second flow channel.

[0022] In some embodiments, the circulation component includes a turbine, a regenerator, a gas-water separation dryer, a cooler, and a compressor unit. The turbine is used to expand the mixed gas to do work, the regenerator is used to cool the mixed gas after expansion and work, and heat the compressed carbon dioxide to form high-pressure carbon dioxide. The gas-water separation dryer is used to remove water vapor in the mixed gas to form carbon dioxide gas, the cooler is used to cool the carbon dioxide gas to liquid, and the compressor unit is used to pressurize the carbon dioxide cooled to liquid.

[0023] In some embodiments, the compressor unit includes a low-pressure compressor, a high-pressure compressor and an intercooler, the low-pressure compressor is used to pressurize the carbon dioxide once, the intercooler is used to cool the carbon dioxide after the primary pressurization, and the high-pressure compressor is used to pressurize the carbon dioxide twice.

[0024] The technical effects of this application are:

[0025] 1. In the present application, by setting a primary cyclone and a secondary cyclone, a primary gas cyclone and a secondary gas cyclone can be formed respectively, which can exert impact, shear and disturbance effects on the ejected liquid hydrocarbon fuel spray, and accelerate the mixing and expansion of the fuel. At the same time, due to the low temperature and high density of the unburned mixed gas, it will move to the periphery of the gas cyclone under the strong centrifugal force of the gas cyclone; while the density of the combustion exhaust gas is relatively small, it will move to the center of the gas cyclone under the influence of the central negative pressure of the gas cyclone, so that the unburned mixed gas and the combustion exhaust gas can be separated, thereby inhibiting the dilution of the combustion exhaust gas. In addition, the primary gas cyclone and the secondary gas cyclone can also induce tumble flow, and finally form a strong composite gas movement and a high-temperature rapid reaction zone of a trapped vortex, thereby realizing the rapid combustion of liquid hydrocarbon fuels to meet the development needs of high efficiency and high power density of marine power systems.

[0026] 2. In the present application, by providing a tertiary swirler, a tertiary gas swirl can be formed, and the tertiary gas swirl can flow along the combustion chamber wall, thereby reducing the wall temperature and preventing the wall temperature from being too high, thereby protecting the wall.

[0027] 3. In the present application, the nozzle adopts a swirl nozzle. Under the action of high pressure and nozzle swirl, the liquid hydrocarbon fuel is broken and atomized, and develops forward in an umbrella-shaped mist, which is more conducive to fuel mixing and expansion.

[0028] 4. In the present application, both the primary tube and the secondary tube are provided with a contraction section and an expansion section. The contraction section is more conducive to exerting impact, shearing and disturbance effects on the liquid hydrocarbon fuel spray, while the expansion section can adapt to the expansion of the liquid hydrocarbon fuel spray. The present application can enhance the transcritical spray disturbance and phase transition of the liquid hydrocarbon fuel by the airflow by setting the contraction section and the expansion section.

[0029] 5. In this application, the carbon dioxide cycle efficiency in the supercritical carbon dioxide cycle power system is high, the power density is large, and the only emission carbon dioxide has a high emission pressure, which can be directly captured and utilized. It is an important technical path to solve high power density power, face climate change, and implement dual carbon goals. For example, the high-pressure carbon dioxide that is recycled again is divided into carbon dioxide for ignition delay, carbon dioxide for speed increase, and carbon dioxide for insulation, which are transported to the first-stage cyclone, the second-stage cyclone, and the third-stage cyclone in three ways, and flow into the first flow channel, the second flow channel, and the combustion chamber through the first-stage cyclone, the second-stage cyclone, and the third-stage cyclone. The carbon dioxide flowing into the secondary cyclone is evenly mixed with oxygen from the pure oxygen supply device before flowing into the secondary cyclone. In this application, the carbon dioxide for ignition delay can avoid direct contact between the fuel in the primary mixing chamber and oxygen, increase the ignition delay period and mixing time, and keep the combustion flame away from the nozzle, reduce the heat load at the nozzle, and avoid high-temperature cracking and carbon deposition of the fuel; the carbon dioxide for speed increase can increase the mass flow rate of the secondary cyclone, increase the kinetic energy of oxygen, and then promote its mixing and combustion with the fuel; the carbon dioxide for insulation plays a cooling role to prevent the temperature of the combustion chamber wall from being too high.

[0030] 6. In the present application, a cooler is provided to cool the carbon dioxide gas to a liquid state. On the one hand, this facilitates the discharge and capture of the circulating incremental carbon dioxide. On the other hand, the carbon dioxide gas is cooled to a liquid state and then pressurized, which is more conducive to the formation of supercritical carbon dioxide and has a high circulation efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments:

[0032] Figure 1 is a schematic structural diagram of a liquid hydrocarbon fuel combustion device provided in one embodiment of the present application;

[0033] Figure 2 This is a schematic diagram of a supercritical carbon dioxide circulation power system provided in one embodiment of the present application.

[0034] Description of Figure Numbers:

[0035] 100, liquid hydrocarbon fuel combustion equipment; 110, nozzle; 111, nozzle; 120, combustion chamber; 121, fluid inlet; 122, wall; 130, primary pipe; 131, first flow channel; 140, secondary pipe; 141, second flow channel; 150, primary cyclone; 160, secondary cyclone; 170, tertiary cyclone; 181, contraction section; 182, expansion section; 191, liquid hydrocarbon fuel; 192, umbrella-shaped mist; 193, primary gas swirl; 194, secondary gas swirl; 195, tertiary gas swirl; 196, carbon dioxide for flame retardation; 197, carbon dioxide for heat insulation; 198, carbon dioxide for speed increase; 199, oxygen;

[0036] 201. Fuel supply equipment; 202. Pure oxygen supply equipment; 203. Turbine; 204. Regenerator; 205. Gas-water separation dryer; 206. Cooler; 207. Low-pressure compressor; 208. High-pressure compressor; 209. Intercooler; 210. High-concentration carbon dioxide and water vapor mixture; 211. Circulating incremental carbon dioxide; 212. High-pressure carbon dioxide. DETAILED DESCRIPTION

[0037] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present application.

[0038] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the specific implementation methods of the present application will be described below with reference to the accompanying drawings. Obviously, the accompanying drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other accompanying drawings and other implementation methods can be obtained based on these drawings without creative work.

[0039] In order to simplify the drawings, only the parts related to the present application are schematically shown in each figure, and they do not represent the actual structure of the product. In addition, in order to simplify the drawings and facilitate understanding, in some figures, only one of the parts with the same structure or function is schematically drawn or marked. In this article, "one" not only means "only one", but also means "more than one".

[0040] It should be further understood that the term “and / or” used in the specification and appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0041] In this document, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0042] In the embodiments shown in the drawings, the indications of directions (such as up, down, left, right, front and back) used to explain the structure and movement of various components of the present application are not absolute but relative. These descriptions are appropriate when these components are in the positions shown in the drawings. If the descriptions of the positions of these components change, the indications of these directions also change accordingly.

[0043] In addition, in the description of the present application, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0044] Supercritical carbon dioxide refers to a carbon dioxide fluid with a temperature exceeding 31°C and a pressure exceeding 7.38MPa. The thermal cycle using supercritical carbon dioxide as the circulating working fluid has the characteristics of high efficiency, high power density, wide power coverage range, low vibration and noise, and wide adaptability of heat sources. It has broad application prospects in nuclear power generation, solar thermal power generation, industrial waste heat power generation, ship power generation and propulsion systems, and fossil fuel combustion power generation.

[0045] Supercritical carbon dioxide cycle power generation is divided into two types: indirect heating supercritical carbon dioxide cycle and direct-fired supercritical carbon dioxide cycle. In the direct-fired supercritical carbon dioxide cycle, high-temperature and high-pressure supercritical carbon dioxide produced by the combustion of hydrocarbon fuels and pure oxygen enters the turbine to expand and do work. After cooling and dehydration, part of the carbon dioxide is pressurized and re-enters the combustion system of the cycle to participate in combustion. The remaining high-pressure carbon dioxide can be directly captured. The working pressure of the entire cycle is generally between 4-30MPa, and the optimized turbine inlet temperature is about 1100℃. The main features of the direct-fired supercritical carbon dioxide cycle are: ① The fuel burns in a mixture of supercritical concentrated carbon dioxide and pure oxygen, without NOx emissions; ② The high-purity carbon dioxide separated by the cycle has high pressure and density, which is easy to capture and utilize directly, thereby achieving complete carbon capture; ③ Higher cycle operation parameters can be achieved, with a maximum working pressure of 30MPa, a direct-fired combustion chamber temperature of 1800℃, and a turbine inlet temperature of 1100℃, and its theoretical cycle thermal efficiency is higher; ④ Although the system is more complex, such as the large number of auxiliary machines, the application prospects are more promising due to the obvious advantages of cycle efficiency. Therefore, the direct-fired supercritical carbon dioxide cycle has broader application prospects in clean zero-carbon power generation, AIP, zero-carbon ship power, distributed power generation, etc., and is beginning to receive increasing attention.

[0046] Existing direct-fired supercritical carbon dioxide circulating combustion systems mostly use gaseous fuels such as natural gas and synthesis gas, and cannot use liquid fuels. Unlike gaseous fuels, liquid fuels are subject to fragmentation, diffusion, phase change, and mixture formation, and in direct-fired circulating combustion environments, liquid fuels also have transcritical spray problems.

[0047] In this regard, the present application provides a liquid hydrocarbon fuel combustion device 100, which is suitable for rapid and efficient combustion in an ultra-rich supercritical carbon dioxide atmosphere and a low excess oxygen coefficient of a direct-fired supercritical carbon dioxide cycle, thereby meeting the development needs of high efficiency and high power density of marine power systems.

[0048] See also Figure 1 In a specific embodiment, the liquid hydrocarbon fuel combustion device 100 includes a nozzle 110, a combustion chamber 120 and a swirl component. The nozzle 110 is used to spray the liquid hydrocarbon fuel 191 to form a liquid hydrocarbon fuel spray. The swirl component is used to generate a gas swirl to exert impact, shear and disturbance effects on the liquid hydrocarbon fuel spray to accelerate the mixing and expansion of the fuel. The liquid hydrocarbon fuel 191 flows through the swirl component and enters the combustion chamber 120 for combustion.

[0049] Among them, the swirl component may include a primary pipe 130, a secondary pipe 140, a primary swirler 150 and a secondary swirler 160. The primary pipe 130 is sleeved on the nozzle 110 and forms a first flow channel 131 for external fluid to flow in between the primary pipe 130 and the nozzle 110. The primary swirler 150 is arranged at the inflow end of the first flow channel 131 so that the fluid flowing in through the first flow channel 131 can form a primary gas swirl 193; correspondingly, the secondary pipe 140 is sleeved on one end of the primary pipe 130 away from the nozzle 110 and forms a second flow channel 141 for external fluid to flow in between the primary pipe 130. The secondary swirler 160 is arranged at the inflow end of the second flow channel 141 so that the fluid flowing in through the second flow channel 141 can form a secondary gas swirl 194, and the secondary pipe 140 is connected to the combustion chamber 120, so that the liquid hydrocarbon fuel spray can flow through the primary pipe 130 and the secondary pipe 140 in sequence and then enter the combustion chamber 120.

[0050] In this embodiment, the external fluid passes through the primary swirler 150 to form a primary gas swirling flow 193, which merges with the ejected liquid hydrocarbon fuel spray in the primary pipe 130. At this time, the primary gas swirling flow 193 can exert impact, shear and disturbance effects on the liquid hydrocarbon fuel spray, thereby accelerating the mixing and expansion of the fuel. In contrast, the external fluid passes through the secondary swirler 160 to form a secondary gas swirling flow 194, which merges with the liquid hydrocarbon fuel spray mixed gas (the mixed gas of the liquid hydrocarbon fuel spray and the primary gas swirling flow 193) in the secondary pipe. At this time, the secondary gas swirling flow 194 can exert impact, shear and disturbance effects on the liquid hydrocarbon fuel spray for a second time, thereby further accelerating the mixing and expansion of the fuel. Moreover, due to the presence of gas swirl (primary gas swirl 193 and secondary gas swirl 194) in the combustion chamber 120, a thermal mixing effect can be formed, that is, the unburned mixed gas has a low temperature and a high density, and will move to the periphery of the combustion chamber 120 under the strong centrifugal force of the gas swirl. At the same time, the density of the combustion exhaust gas is relatively small, and it will move to the center of the combustion chamber 120 under the influence of the negative pressure at the center of the swirl, thereby achieving the separation of the unburned mixed gas and the combustion exhaust gas and inhibiting the dilution of the combustion exhaust gas. In addition, the primary gas swirl 193 and the secondary gas swirl 194 can also induce tumble flow, and finally form a strong composite gas movement and a high-temperature rapid reaction zone of a trapped vortex, thereby achieving rapid combustion of the liquid hydrocarbon fuel 191, so as to meet the development needs of high efficiency and high power density of marine power systems.

[0051] In actual use, see Figure 1 and Figure 2 , the fluid entering through the first flow channel 131 and the second flow channel 141 includes the high-pressure carbon dioxide 212 discharged after combustion, and the circulation efficiency is higher. Specifically, the discharged high-pressure carbon dioxide 212 is recovered and divided into carbon dioxide 196 for flame retardancy and carbon dioxide 198 for acceleration, which are respectively transported to the primary cyclone 150 and the secondary cyclone 160 through the delivery pipeline, and flow into the first flow channel 131 and the second flow channel 141 through the primary cyclone 150 and the secondary cyclone 160. The carbon dioxide 196 for flame retardancy can prevent the fuel in the primary mixing chamber from directly contacting the oxygen 199, increase the flame retardancy period and mixing time, and keep the combustion flame away from the nozzle 110, reduce the heat load at the nozzle 110, and avoid high-temperature cracking and carbon deposition of the fuel; the carbon dioxide 198 for acceleration can increase the mass flow rate of the secondary vortex, increase the kinetic energy of oxygen 199, and then promote its mixing and combustion with the fuel.

[0052] Specifically, before the accelerating carbon dioxide 198 enters the secondary cyclone 160, it is premixed with pure oxygen and then passes through the secondary cyclone 160 together to form a secondary gas cyclone 194. Among them, the flow rate of oxygen 199 is low, much smaller than the flow rate of the combustion delay carbon dioxide 196, and the mass ratio between oxygen 199 and the combustion delay carbon dioxide 196 is about 1:9.

[0053] Furthermore, the swirl assembly may also include a tertiary swirler 170. A fluid inlet 121 for external fluid to flow into is provided on one side of the combustion chamber 120 facing the secondary tube 140, and the tertiary swirler 170 is provided at the fluid inlet 121, so that the fluid flowing into the combustion chamber 120 through the fluid inlet 121 forms a tertiary gas swirl 195. The tertiary gas swirl 195 can flow along the wall 122 of the combustion chamber 120, thereby reducing the temperature of the wall 122 and preventing the wall 122 from being too high in temperature, so as to protect the wall 122.

[0054] In contrast, the fluid entering the combustion chamber 120 from the fluid inlet 121 includes the high-pressure carbon dioxide 212 discharged after combustion, that is, the discharged high-pressure carbon dioxide 212 is recovered and divided into carbon dioxide 196 for delaying combustion, carbon dioxide 198 for accelerating, and carbon dioxide 197 for heat insulation, and is respectively transported to the primary cyclone 150, the secondary cyclone 160, and the tertiary cyclone 170 in three ways, and flows into the first flow channel 131, the second flow channel 141 and the combustion chamber 120 through the primary cyclone 150, the secondary cyclone 160, and the tertiary cyclone 170. In this way, by adjusting the flow rates of the three carbon dioxides of carbon dioxide 196 for delaying combustion, carbon dioxide 198 for accelerating, and carbon dioxide 197 for heat insulation, the carbon dioxide mass fraction and the exhaust temperature in the combustion chamber 120 can be adjusted, thereby meeting the requirements of the direct-fired supercritical carbon dioxide cycle.

[0055] In the above-mentioned embodiments, the nozzle 110 preferably adopts a swirl nozzle. The liquid hydrocarbon fuel 191 is broken and atomized under the action of high pressure and the swirl of the nozzle 110 to form a fuel swirl spray, and develops forward in an umbrella-shaped mist shape 192, which is more conducive to fuel mixing and the gas swirl exerts impact, shear and disturbance effects on the fuel swirl spray, which is conducive to the rapid combustion of the liquid hydrocarbon fuel 191.

[0056] In a preferred embodiment, see Figure 1 , a primary mixing chamber for fluid mixing is formed inside the first-stage pipe 130, and the primary mixing chamber has a contraction section 181 and an expansion section 182 which are axially connected, and the contraction section 181 is arranged toward the nozzle 110. By setting the contraction section 181, the fuel swirl spray can be disturbed and impacted during the forward movement of the fuel swirl spray. At the same time, the entering combustion-retarding carbon dioxide 196 will also be accelerated in the contraction section 181, and the impact, shearing and disturbance effects exerted on the fuel swirl spray are also better, which is more conducive to fuel mixing and expansion; the expansion section 182 can adapt to the expansion of the liquid hydrocarbon fuel spray. By setting the contraction section 181 and the expansion section 182, the transcritical spray disturbance and phase transition of the liquid hydrocarbon fuel 191 by the airflow can be enhanced.

[0057] Relatively speaking, a secondary mixing chamber for fluid mixing is formed inside the secondary pipe 140, and the secondary mixing chamber has an axially connected contraction section 181 and an expansion section 182. The contraction section 181 is arranged toward the primary pipe 130, so as to optimize the impact, shearing and disturbance effects exerted by the secondary gas swirl 194 on the fuel swirl spray, further accelerate the mixing and expansion of the fuel, and at the same time, the expansion section 182 can adapt to the expansion of the liquid hydrocarbon fuel spray. By setting the contraction section 181 and the expansion section 182, the transcritical spray disturbance and phase transition of the liquid hydrocarbon fuel 191 caused by the airflow can be enhanced.

[0058] Specifically, the inner wall of the primary tube 130 is formed with an outwardly convex arc surface toward the central axis of the primary tube 130, and the primary mixing chamber can form the above-mentioned contraction section 181 at the convex part of the arc surface, and form the above-mentioned expansion section 182 at the convex part of the arc surface away from the nozzle 110. In contrast, the inner wall of the secondary tube 140 is formed with an outwardly convex arc surface toward the central axis of the secondary tube 140, and the secondary mixing chamber is formed with the above-mentioned contraction section 181 at the convex part of the arc surface, and forms the above-mentioned expansion section 182 at the convex part of the arc surface away from the primary tube 130.

[0059] Furthermore, the nozzle 110 has a nozzle 111, which is located at the protrusion of the primary mixing chamber, that is, the contraction section 181 of the primary mixing chamber in the first-stage pipe 130, which is conducive to the transcritical spray disturbance and phase transition of the liquid hydrocarbon fuel 191 by the airflow. In contrast, the end of the first-stage pipe 130 away from the nozzle 110 is located at the protrusion of the secondary mixing chamber, that is, the contraction section 181 of the secondary mixing chamber in the second-stage pipe 140.

[0060] In all the above embodiments, the primary tube 130 and the secondary tube 140 preferably adopt a zoom Venturi tube, which has a simple structure, low production cost, and is easy to purchase, which is conducive to the maintenance and replacement of the primary tube 130 and the secondary tube 140.

[0061] The liquid hydrocarbon fuel combustion equipment 100 provided in the present application adopts three groups of gas swirls. The primary gas swirl 193 increases the ignition delay period, increases the premixing time, and avoids the nozzle 110 from being overheated; the secondary gas swirl 194 increases the speed of oxygen gas flow and promotes the formation of the mixed gas; the tertiary gas swirl 195 plays a cooling role to prevent the wall 122 from being overheated; at the same time, it is assisted by the zooming structure of the primary tube 130 and the secondary tube 140 (that is, the structural setting of the axially connected contraction section 181 and the expansion section 182) to enhance the transcritical spray disturbance and phase transition of the liquid fuel by the airflow. The present application utilizes the coordination of the zooming structure of the swirl nozzle, the swirler (the primary swirler 150, the secondary swirler 160 and the tertiary swirler 170), and the zooming venturi tube to ultimately achieve the effect of fast and efficient combustion, and meet the development needs of high efficiency and high power density of the marine power system.

[0062] See also Figure 2The present application also provides a direct-fired supercritical carbon dioxide circulation system, including a fuel supply device 201, a pure oxygen supply device 202, a circulation component, a delivery pipeline, and a liquid hydrocarbon fuel combustion device 100 provided in any of the above embodiments. The fuel supply device 201 is used to supply liquid hydrocarbon fuel 191 to the nozzle 110, and the pure oxygen supply device 202 is used to supply oxygen 199 to the second flow channel 141.

[0063] In actual use, the liquid hydrocarbon fuel 191 is burned to form a mixed gas of carbon dioxide and water vapor. The circulation component is used to receive the mixed gas and the mixed gas is circulated by the circulation component to obtain high-purity high-pressure carbon dioxide 212 (the carbon dioxide content is usually more than 99%). The high-pressure carbon dioxide 212 is respectively transported to the primary cyclone 150, the secondary cyclone 160, and the tertiary cyclone 170 through the transmission pipeline, and flows into the first flow channel 131, the second flow channel 141 and the combustion chamber 120 through the primary cyclone 150, the secondary cyclone 160, and the tertiary cyclone 170. Among them, the carbon dioxide flowing into the secondary cyclone 160 should be evenly mixed with the oxygen 199 from the pure oxygen supply device 202 before flowing into the secondary cyclone 160.

[0064] Specifically, the flow rate of oxygen 199 supplied by the pure oxygen supply device 202 should be less than the flow rate of high-pressure carbon dioxide 212 (i.e., carbon dioxide 198 for accelerating) delivered by the delivery pipeline to the second flow channel 141. Specifically, the mass ratio between oxygen 199 and carbon dioxide 196 for delaying combustion is approximately 1:9.

[0065] In a specific embodiment, the circulation component further includes a turbine 203, a regenerator 204, a gas-water separation dryer 205, a cooler 206, and a compressor unit. The turbine 203 is used to expand the mixed gas to do work, the gas-water separation dryer 205 is used to remove water vapor in the mixed gas to form carbon dioxide gas, the cooler 206 is used to cool the carbon dioxide gas to liquid, the compressor unit is used to pressurize the carbon dioxide cooled to liquid, and the regenerator 204 uses the mixed gas after expansion and work to heat the compressed carbon dioxide to form the required high-pressure carbon dioxide 212.

[0066] In this embodiment, the carbon dioxide gas is cooled to liquid by setting a cooler 206. On the one hand, it is convenient to discharge and capture the circulating incremental carbon dioxide 211. On the other hand, the carbon dioxide gas is cooled to liquid and then pressurized, which is more conducive to the formation of supercritical carbon dioxide and has high circulation efficiency.

[0067] Furthermore, the compressor unit includes a low-pressure compressor 207, a high-pressure compressor 208 and an intercooler 209. The low-pressure compressor 207 is used for primary pressurization of the carbon dioxide, the high-pressure compressor 208 is used for secondary pressurization of the carbon dioxide, and the intercooler 209 is used to cool the carbon dioxide after the primary pressurization to reduce its temperature when it enters the high-pressure compressor 208, thereby reducing the compression power consumption of the high-pressure compressor 208 and improving the specific power of the entire unit.

[0068] In this embodiment, the high-pressure carbon dioxide 212 heated by the regenerator 204 is divided into three paths: carbon dioxide 196 for flame retardancy, carbon dioxide 198 for acceleration, and carbon dioxide 197 for heat insulation. The carbon dioxide 198 for acceleration is mixed with oxygen 199 from the pure oxygen supply device 202 to form a mixed gas of carbon dioxide 198 for acceleration and oxygen 199. The carbon dioxide 196 for flame retardancy, the mixed gas of carbon dioxide 198 for acceleration and oxygen 199, and the carbon dioxide 197 for heat insulation enter the liquid hydrocarbon fuel combustion device 100 in three paths and mix with the liquid hydrocarbon fuel from the fuel supply device 201. The hydrocarbon fuel 191 burns to form a high-temperature and high-pressure high-concentration carbon dioxide and water vapor mixture 210, which enters the turbine 203 to expand and do work, then enters the regenerator 204 to cool, and then enters the gas-water separation dryer 205 to complete gas-water separation and drying. Subsequently, it enters the cooler 206 to be cooled to a liquid state, and the circulating incremental carbon dioxide 211 is discharged and captured. The remaining carbon dioxide enters the low-pressure compressor 207 for pressurization, enters the intercooler 209 for cooling, and then enters the high-pressure compressor 208 for pressurization, and enters the regenerator 204 for heating to form high-pressure carbon dioxide 212, forming a new round of circulation.

[0069] The supercritical carbon dioxide cycle power system proposed in this application has high cycle efficiency and high power density; and the only emission, carbon dioxide, has a high emission pressure and can be directly captured and utilized. It is an important technical path to solve high power density power, face climate change, and implement dual carbon goals.

[0070] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0071] It should be noted that the above embodiments can be freely combined as needed. The above are only preferred implementations of this application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of this application, and these improvements and modifications should also be regarded as the protection scope of this application.

Claims

1. A liquid hydrocarbon fuel combustion device, suitable for direct-fired supercritical carbon dioxide cycle combustion of liquid fuel, characterized in that: include: A nozzle, a combustion chamber and a swirl assembly, wherein the nozzle is used to spray liquid hydrocarbon fuel, and the sprayed liquid hydrocarbon fuel flows through the swirl assembly and then enters the combustion chamber; The swirl assembly includes a primary pipe, a secondary pipe, a primary swirler and a secondary swirler, the primary pipe is sleeved on the nozzle and a first flow channel for external fluid to flow into is formed between the primary pipe and the nozzle, the secondary pipe is sleeved on an end of the primary pipe away from the nozzle and a second flow channel for external fluid to flow into is formed between the primary pipe, and the secondary pipe is connected to the combustion chamber; The primary cyclone is arranged at the inlet end of the first flow channel so that the fluid flowing into the first flow channel forms a primary gas cyclone, and the secondary cyclone is arranged at the inlet end of the second flow channel so that the fluid flowing into the second flow channel forms a secondary gas cyclone.

2. The liquid hydrocarbon fuel combustion equipment according to claim 1, characterized in that: The cyclone assembly also includes a tertiary cyclone; A fluid inlet for external fluid to flow into is arranged on one side of the combustion chamber facing the secondary pipe, and the tertiary swirler is arranged at the fluid inlet so that the fluid flowing into the combustion chamber through the fluid inlet forms a tertiary gas swirling flow.

3. The liquid hydrocarbon fuel combustion equipment according to claim 1, characterized in that: The nozzle comprises a swirl nozzle.

4. The liquid hydrocarbon fuel combustion equipment according to claim 1, characterized in that: A primary mixing chamber for fluid mixing is formed inside the primary tube, and the primary mixing chamber has an axially connected contraction section and an expansion section, and the contraction section is arranged toward the nozzle; and a secondary mixing chamber for fluid mixing is formed inside the secondary tube, and the secondary mixing chamber has an axially connected contraction section and an expansion section, and the contraction section is arranged toward the primary tube.

5. The liquid hydrocarbon fuel combustion equipment according to claim 3, characterized in that: The inner wall of the first-stage tube forms an outwardly convex arc surface toward the central axis of the first-stage tube, the first mixing chamber forms the contraction section at the convex part of the arc surface, and forms the expansion section at the convex part of the arc surface away from the nozzle; and, the inner wall of the second-stage tube forms an outwardly convex arc surface toward the central axis of the second-stage tube, the second mixing chamber forms the contraction section at the convex part of the arc surface, and forms the expansion section at the convex part of the arc surface away from the first-stage tube.

6. The liquid hydrocarbon fuel combustion equipment according to claim 4, characterized in that: The primary tube and the secondary tube are both venturi tubes.

7. A direct-fired supercritical carbon dioxide circulation system, characterized in that: include: A fuel supply device, a pure oxygen supply device, a circulation component, a delivery pipeline, and a liquid hydrocarbon fuel combustion device as claimed in any one of claims 1 to 6; wherein the swirl component further comprises a tertiary swirler, which is arranged at the fluid inlet of the combustion chamber so that the fluid flowing into the combustion chamber through the fluid inlet forms a tertiary gas swirl; The fuel supply device is used to supply liquid hydrocarbon fuel to the nozzle, and the pure oxygen supply device is used to supply oxygen to the second flow channel. The liquid hydrocarbon fuel forms a mixed gas of carbon dioxide and water vapor after combustion. The circulation component is used to receive the mixed gas. The mixed gas is circulated by the circulation component to obtain high-pressure carbon dioxide. The conveying pipeline conveys the circulated high-pressure carbon dioxide to the first cyclone, the second cyclone and the third cyclone respectively, and flows into the first flow channel, the second flow channel and the combustion chamber through the first cyclone, the second cyclone and the third cyclone; The carbon dioxide flowing into the secondary cyclone is evenly mixed with the oxygen from the pure oxygen supply device before flowing into the secondary cyclone.

8. The direct-fired supercritical carbon dioxide circulation system according to claim 7, characterized in that: The oxygen flow rate supplied by the pure oxygen supply device is smaller than the high-pressure carbon dioxide flow rate delivered by the delivery pipeline to the second flow channel.

9. The direct-fired supercritical carbon dioxide circulation system according to claim 7, characterized in that: The circulation component includes a turbine, a regenerator, a gas-water separation dryer, a cooler, and a compressor unit. The turbine is used to expand the mixed gas to do work. The regenerator is used to cool the mixed gas after expansion and work, and heat the compressed carbon dioxide to form high-pressure carbon dioxide. The gas-water separation dryer is used to remove water vapor in the mixed gas to form carbon dioxide gas. The cooler is used to cool the carbon dioxide gas to liquid, and the compressor unit is used to pressurize the carbon dioxide cooled to liquid.

10. The direct-fired supercritical carbon dioxide circulation system according to claim 9, characterized in that: The compressor unit comprises a low-pressure compressor, a high-pressure compressor and an intercooler. The low-pressure compressor is used for primary pressurization of carbon dioxide, the intercooler is used for cooling the primary pressurized carbon dioxide, and the high-pressure compressor is used for secondary pressurization of carbon dioxide.

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