fuel heating method

Abstract

The present invention provides a fuel heating method, which relates to the technical field of fuel heating. The fuel heating system provided by the present invention includes: a nitrogen source, a constant temperature fuel container and a heating component; the nitrogen source is in fluid communication with the gas phase region of the constant temperature fuel container, and the liquid phase region of the constant temperature fuel container is in fluid communication with the heating component; the heating component has a heating channel, and a plurality of heating elements are sequentially arranged along the heating channel. The fuel heating method provided by the present invention can realize non-uniform distribution of temperature and heat flow in each region of the heating channel, can simulate the regenerative cooling process of the engine, and is suitable for studying the influence of the regenerative cooling process on injection.

Description

Technical Field

[0001] The invention relates to the technical field of fuel oil heating, and in particular to a fuel oil heating method. Background Art

[0002] Rocket engines can be used for the propulsion of spacecraft and the flight of weapons such as missiles. Scramjet engines can achieve hypersonic flight of aircraft in the atmosphere, and rotating detonation engines can be used for future hypersonic aircraft in the atmosphere. During the operation of a rocket engine, the temperature of the combustion chamber is extremely high and can even exceed 3000K, exceeding the bearing limit of existing structural materials. Using fuel as a regenerative coolant to actively cool the combustion chamber wall can, on the one hand, effectively solve the thermal protection problem of the aircraft, and on the other hand, increase the fuel energy, directly mix it with the incoming air in a supercritical state / gaseous state, eliminate the atomization process, and improve the engine's specific impulse thrust performance. Fuel has different physical properties from liquid or gaseous fuel in the near-critical and supercritical states. During the flow in the cooling channel, drastic physical property changes will occur, which will affect the injection of fuel.

[0003] In order to study the working process of an engine fueled by supercritical fuel, it is necessary to heat the fuel to a supercritical state under engine ground test conditions to study the injection characteristics of the fuel under different heat exchange conditions, injection pressures, and temperatures, so as to restore the impact of the actual engine regenerative cooling working process on the injection.

[0004] However, in the actual operation of the engine, the temperature and heat flow in the cooling channel have different distributions at different locations, and the existing supercritical fuel supply system basically ignores the time non-stationarity and spatial non-uniformity of heat flow and temperature during the heat exchange of the fuel in the heating section to the supercritical state. When the fuel is heated unevenly or the temperature rises too quickly during the heating process, the amount of fuel coking will increase, which not only affects the experimental study of the impact of the regenerative cooling process on the injection, but also affects the subsequent heating efficiency of the fuel. Summary of the invention

[0005] The object of the present invention is to provide a fuel heating method to simulate the regenerative cooling heat exchange process, which is suitable for studying the influence of the regenerative cooling process on injection.

[0006] In a first aspect, the present invention provides a fuel heating system, comprising: a nitrogen source, a constant temperature fuel container and a heating component;

[0007] The nitrogen source is in fluid communication with the gas phase region of the constant temperature fuel container, and the liquid phase region of the constant temperature fuel container is in fluid communication with the heating component;

[0008] The heating assembly has a heating channel, and a plurality of heating elements are arranged in sequence along the heating channel.

[0009] In combination with the first aspect, the present invention provides a first possible implementation of the first aspect, wherein the heating assembly comprises: a heat exchange tube, a plurality of fuel temperature sensors and a plurality of heating elements;

[0010] The inner cavity of the heat exchange tube serves as the heating channel, and the plurality of heating elements are arranged in sequence along the heat exchange tube and in contact with the heat exchange tube;

[0011] A plurality of the fuel temperature sensors are arranged in sequence along the heat exchange tube, and the temperature probes of the fuel temperature sensors extend into the heating channel.

[0012] In combination with the first possible implementation of the first aspect, the present invention provides a second possible implementation of the first aspect, wherein the heating assembly further comprises: a controller and a plurality of wall temperature sensors;

[0013] The positions of the plurality of wall temperature sensors correspond one-to-one to the positions of the plurality of heating elements, and the wall temperature sensors are used to detect the temperature of the heat exchange tube;

[0014] The plurality of heating elements, the plurality of fuel temperature sensors and the plurality of wall temperature sensors are respectively connected to the controller.

[0015] In combination with the first possible implementation manner of the first aspect, the present invention provides a third possible implementation manner of the first aspect, wherein the outside of the heat exchange tube is wrapped with a thermal insulation member.

[0016] In combination with the first aspect, the present invention provides a fourth possible implementation of the first aspect, wherein at least one of a pressure reducer, a first pressure sensor and a discharge valve is installed between the nitrogen source and the constant temperature fuel container.

[0017] In combination with the first aspect, the present invention provides a fifth possible implementation of the first aspect, wherein at least one of a shut-off valve, a filter, a flow meter, a regulating valve and a first temperature sensor is installed between the constant temperature fuel container and the heating assembly.

[0018] In combination with the first aspect, the present invention provides a sixth possible implementation of the first aspect, wherein the heating component is fluidically connected to the injector, and at least one of a second temperature sensor and a second pressure sensor is installed between the heating component and the injector.

[0019] In a second aspect, the fuel oil heating method provided by the present invention adopts the fuel oil heating system described in the first aspect, and comprises the following steps:

[0020] Set the first target temperature T of the constant temperature fuel container 0 ;

[0021] Set the second target temperature T of each area of ​​the heating channel in the heating component i , the second target temperature T along the heating channel i It conforms to the sigmoid function, and the sigmoid function has a second-order derivative;

[0022] The fuel in the constant temperature fuel container is pressurized by a nitrogen source, and the fuel is caused to flow from the constant temperature fuel container into the heating channel.

[0023] In combination with the second aspect, the present invention provides a first possible implementation of the second aspect, wherein the second target temperature T i The following calculation formula is met:

[0024]

[0025] Among them, i=1, 2, 3...k, k is the number of regional segments in the heating channel.

[0026] In combination with the second aspect, the present invention provides a second possible implementation of the second aspect, wherein the fuel heating method includes:

[0027] When the fuel temperature in any area of ​​the heating channel is lower than the second target temperature T corresponding to the area i When the heating element corresponding to the area is controlled to heat the fuel;

[0028] When the fuel temperature in any area of ​​the heating channel is greater than or equal to the second target temperature T corresponding to the area i When the heating element corresponding to the area is controlled to stop heating.

[0029] The embodiments of the present invention bring the following beneficial effects: a nitrogen source is connected to the gas phase fluid of a constant temperature fuel container, a liquid phase fluid of the constant temperature fuel container is connected to the heating component fluid, the heating component has a heating channel, and a plurality of heating elements are sequentially arranged along the heating channel. The heating elements can realize non-uniform distribution of temperature and heat flow in various regions of the heating channel, and can simulate the engine regenerative cooling process, which is suitable for studying the influence of the regenerative cooling process on injection.

[0030] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the related technologies, the drawings required for use in the specific embodiments or the related technical descriptions will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0032] Figure 1 A schematic diagram of a fuel heating system provided by an embodiment of the present invention;

[0033] Figure 2 A schematic diagram of a heating component of a fuel heating system provided in an embodiment of the present invention;

[0034] Figure 3 This is a target temperature distribution curve for each heating section of a heat exchange tube in a fuel heating system provided in an embodiment of the present invention.

[0035] Icons: 001 - nitrogen source; 002 - constant temperature fuel oil container; 003 - heating assembly; 301 - heating channel; 310 - heating element; 320 - heat exchange tube; 330 - fuel oil temperature sensor; 340 - controller; 350 - wall temperature sensor; 360 - thermal insulation; 004 - pressure reducer; 005 - first pressure sensor; 006 - discharge valve; 007 - stop valve; 008 - filter; 009 - flow meter; 010 - regulating valve; 011 - first temperature sensor; 012 - injector; 013 - second temperature sensor; 014 - second pressure sensor. DETAILED DESCRIPTION

[0036] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance. Physical quantities in formulas, if not separately marked, should be understood as basic quantities of the base units of the International System of Units, or derived quantities derived from the basic quantities through mathematical operations such as multiplication, division, differentiation or integration.

[0038] In the description of the present invention, 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 it can be indirectly connected 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 the present invention can be understood according to specific circumstances.

[0039] like Figure 1 As shown, the fuel heating system provided by the embodiment of the present invention includes: a nitrogen source 001, a constant temperature fuel container 002 and a heating component 003;

[0040] The nitrogen source 001 is in fluid communication with the gas phase region of the constant temperature fuel container 002, and the liquid phase region of the constant temperature fuel container 002 is in fluid communication with the heating component 003;

[0041] The heating assembly 003 has a heating channel 301 , and a plurality of heating elements 310 are sequentially arranged along the heating channel 301 .

[0042] The use of multiple heating elements 310 can heat different areas in the heating channel 301 separately, and can achieve non-uniform distribution of temperature and heat flow in each area of ​​the heating channel 301, which can simulate the engine regeneration cooling process and is suitable for studying the impact of the regeneration cooling process on injection. During the simulation test, high-pressure nitrogen is used to pressurize the gas phase area in the constant temperature fuel container 002, so that the fuel in the constant temperature fuel container 002 is pressurized and flows into the heating component 003, which not only stabilizes the pressure and is easy to control, but also improves the test safety of the fuel.

[0043] like Figure 1 and Figure 2As shown, in an embodiment of the present invention, the heating assembly 003 includes: a heat exchange tube 320, a plurality of fuel temperature sensors 330 and a plurality of heating elements 310; the inner cavity of the heat exchange tube 320 serves as a heating channel 301, and the plurality of heating elements 310 are arranged in sequence along the heat exchange tube 320 and in contact with the heat exchange tube 320; the plurality of fuel temperature sensors 330 are arranged in sequence along the heat exchange tube 320, and the temperature probes of the fuel temperature sensors 330 extend into the heating channel 301.

[0044] The heating temperature of the plurality of heating elements 310 can be set respectively, so as to realize non-uniform distribution of temperature and heat flow in each area along the axial direction of the heat exchange tube 320. The temperature probe of the fuel temperature sensor 330 extends to the heating end area of ​​the heating element 310 in the heat exchange tube 320.

[0045] Furthermore, the heating component 003 also includes: a controller 340 and multiple wall temperature sensors 350; the positions of the multiple wall temperature sensors 350 correspond one-to-one to the positions of the multiple heating elements 310, and the wall temperature sensors 350 are used to detect the temperature of the heat exchange tube 320; the multiple heating elements 310, the multiple fuel temperature sensors 330 and the multiple wall temperature sensors 350 are respectively connected to the controller 340.

[0046] Specifically, the probe of the wall temperature sensor 350 extends to the wall surface of the heat exchange tube 320 where the heating element 310 is attached, so that the heating temperature of the heat exchange tube 320 by the heating element 310 is detected by the wall temperature sensor 350 .

[0047] Furthermore, the outside of the heat exchange tube 320 is wrapped with a heat insulating member 360, and the heat insulating member 360 can prevent the heat in the heating component 003 from being lost.

[0048] Furthermore, at least one of a pressure reducer 004 , a first pressure sensor 005 and a discharge valve 006 is installed between the nitrogen source 001 and the constant temperature fuel container 002 .

[0049] The pressure reducer 004 can adjust the gas supply pressure from the nitrogen source 001 to the constant temperature fuel container 002, the first pressure sensor 005 can detect the intake pressure at the entrance of the constant temperature fuel container 002, and the discharge valve 006 can release the pressure in the constant temperature fuel container 002 by leakage. In this embodiment, the pressure reducer 004, the first pressure sensor 005 and the discharge valve 006 can be installed between the nitrogen source 001 and the constant temperature fuel container 002 in sequence.

[0050] Furthermore, at least one of a stop valve 007 , a filter 008 , a flow meter 009 , a regulating valve 010 and a first temperature sensor 011 is installed between the constant temperature fuel container 002 and the heating component 003 .

[0051] Specifically, the stop valve 007, the filter 008, the flow meter 009, the regulating valve 010 and the first temperature sensor 011 can be installed in sequence between the constant temperature fuel container 002 and the heating component 003. In addition, some of the stop valve 007, the filter 008, the flow meter 009, the regulating valve 010 and the first temperature sensor 011 can be designed by default according to the working requirements of the simulation system.

[0052] Furthermore, the heating assembly 003 is in fluid communication with the injector 012, and at least one of a second temperature sensor 013 and a second pressure sensor 014 is installed between the heating assembly 003 and the injector 012. The temperature of the injected fuel can be detected by the second temperature sensor 013, and the fuel injection pressure of the injector 012 can be detected by the second pressure sensor 014.

[0053] like Figure 1 and Figure 2 As shown, the fuel heating method provided in the embodiment of the present invention can adopt the fuel heating system described in the above embodiment, and includes the following steps:

[0054] Set the first target temperature T of the constant temperature fuel container 002 0 ;

[0055] Set the second target temperature T of each area of ​​the heating channel 301 in the heating component 003 i , along the heating channel 301 the second target temperature T i It conforms to the sigmoid function, and the sigmoid function has a second-order derivative;

[0056] The fuel in the constant temperature fuel container 002 is pressurized by the nitrogen source 001 , and the fuel is made to flow from the constant temperature fuel container 002 into the heating channel 301 .

[0057] Specifically, the sigmoid function is The first target temperature T 0 It can be set to 400K. The heating channel 301 can be set to multiple heating areas. The number of heating areas is set to 8, and can be increased or decreased according to test needs. i is the area number in the heating channel 301. i In the case of conforming to the sigmoid function, the temperature distribution in the heating channel 301 can be smoothed (see Figure 3 ), which can effectively reduce the amount of coking of fuel during the preheating process.

[0058] In the embodiment of the present invention, the second target temperature T i The following calculation formula is met:

[0059]

[0060] Wherein, i=1, 2, 3...s, s is the number of area segments in the heating channel 301. s Can be set to 800K, T s The final target temperature of the last heating zone of the heating component 003 can be increased or decreased according to the test needs.

[0061] Furthermore, the fuel heating method includes: when the fuel temperature in any area of ​​the heating channel 301 is lower than the second target temperature T corresponding to the area i When the fuel temperature in any area of ​​the heating channel 301 is greater than or equal to the second target temperature T corresponding to the area, the heating element 310 corresponding to the area is controlled to heat the fuel; when the fuel temperature in any area of ​​the heating channel 301 is greater than or equal to the second target temperature T corresponding to the area i When the heating element 310 corresponding to the area is controlled to stop heating.

[0062] The control voltage of each heating element 310 is 0 to 220V, and the output voltage can be controlled in real time, thereby controlling the heating power. The constant temperature fuel container 002 is used for primary heat storage, and the kerosene can be heated to a supercritical state through the heating component 003, which can accurately and realistically simulate the non-uniform distribution characteristics of temperature and heat flow space in the cooling channel during the engine regenerative cooling process, and is suitable for studying the impact of the regenerative cooling process on the injection.

[0063] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A fuel heating method, characterized in that: The fuel heating method adopts a fuel heating system, which comprises: a nitrogen source (001), a constant temperature fuel container (002) and a heating component (003); the nitrogen source (001) is in fluid communication with the gas phase region of the constant temperature fuel container (002), and the liquid phase region of the constant temperature fuel container (002) is in fluid communication with the heating component (003); the heating component (003) has a heating channel (301), and a plurality of heating elements (310) are sequentially arranged along the heating channel (301); The fuel heating method comprises the following steps: Setting a first target temperature T0 of a constant temperature fuel container (002); Setting the second target temperature T of each area of ​​the heating channel (301) in the heating assembly (003) i , along the heating channel (301) the second target temperature T i It conforms to the sigmoid function, and the sigmoid function has a second-order derivative; Pressurizing the fuel in the constant temperature fuel container (002) through a nitrogen source (001), and allowing the fuel to flow from the constant temperature fuel container (002) into the heating channel (301); The second target temperature T i The following calculation formula is met: Wherein, i=1, 2, 3...k, and k is the number of area segments in the heating channel (301).

2. The fuel heating method according to claim 1, characterized in that: The fuel heating method comprises: When the fuel temperature in any area of ​​the heating channel (301) is lower than the second target temperature T corresponding to the area i When the heating element (310) corresponding to the area is controlled to heat the fuel; When the fuel temperature in any area of ​​the heating channel (301) is greater than or equal to the second target temperature T corresponding to the area i When the heating element (310) corresponding to the area is controlled to stop heating.

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