Supercooling liquid oxygen heat exchanger applied to low-temperature liquid rocket

Abstract

The utility model relates to the technical field of heat exchangers, in particular to a supercooled liquid oxygen heat exchanger applied to a low-temperature liquid rocket, which comprises a shell, a heat exchange core and a supporting mechanism, a liquid nitrogen inlet and a nitrogen outlet are arranged on the shell, and the liquid nitrogen inlet and the nitrogen outlet are oppositely arranged; the heat exchange core body is located in the shell, a liquid oxygen inlet and a liquid oxygen outlet are formed in the shell, and the liquid oxygen inlet and the liquid oxygen outlet communicate with an inlet and an outlet of the heat exchange core body correspondingly; the two ends of the supporting mechanism are connected with the outer shell of the heat exchange core and the inner wall of the shell correspondingly. The shell, the heat exchange core and the supporting mechanism are all made of aluminum materials. The heat exchanger is simple in structure and reliable in strength, the labor cost during installation and the difficulty of later cleaning and maintenance are reduced, and the labor cost of later cleaning and maintenance of the heat exchanger can also be reduced.

Description

Technical Field

[0001] This utility model relates to the field of heat exchanger technology, and in particular to a subcooled liquid oxygen heat exchanger used in cryogenic liquid rockets. Background Technology

[0002] With the continuous progress of my country's aerospace industry, the requirements for the performance and thrust of cryogenic liquid rocket engines are also constantly increasing. Liquid oxygen has the characteristics of being non-toxic, having high fuel density, low cost, high thrust, being easy to produce, and having strong oxidizing properties. Therefore, liquid oxygen is often used as a very important combustion oxidizer and propellant for rocket engines, which can greatly increase the thrust of rocket engines and improve their performance and efficiency.

[0003] Liquid oxygen at atmospheric pressure has a boiling point of approximately 90K (-183℃), classifying it as a cryogenic propellant. Therefore, during long-distance transport, complex flows such as two-phase flow, geysers, wavy flow, annular flow, and flash evaporation occur within the pipeline, leading to vibrations and cavitation in the turbopump. Furthermore, supercooled liquid oxygen has a higher density than its non-supercooled counterpart, allowing for more oxygen to participate in combustion within the same rocket propellant tank volume, thus further enhancing rocket engine thrust. Therefore, supercooling is necessary for liquid oxygen during actual rocket propellant loading. Current liquid oxygen supercooling methods typically utilize liquid nitrogen, with a saturation temperature of approximately 77K (-196.15℃) at atmospheric pressure, to supercool the liquid oxygen in a supercooler.

[0004] Currently, plate-fin heat exchangers are commonly used for supercooling liquid oxygen during rocket refueling in China, which have the following advantages:

[0005] 1. Because the fins of a plate-fin heat exchanger have holes, gaps, bends, etc., they can greatly destroy the thermal boundary layer that prevents heat transfer, resulting in high heat transfer intensity.

[0006] 2. Plate-fin heat exchangers typically have fins made of aluminum alloy with a thickness of about 0.2mm, and the overall layout is compact. Therefore, plate-fin heat exchangers have a compact structure and are lightweight.

[0007] 3. Plate-fin heat exchangers have a high degree of compactness, typically ranging from 1500-2500 m². 2 / m 3 The compactness of ordinary shell-and-tube heat exchangers is typically 50-500m². 2 / m 3 .

[0008] The heat exchanger core is assembled by stacking and brazing to form the heat exchange core, which is used for heat exchange between hot and cold fluids. The subcooler shell and the heat exchanger are connected to each other by welding at both ends using steel-aluminum joints.

[0009] Traditional plate-fin heat exchangers have a complex structure, with the internal heat exchange core typically made of aluminum and the external shell usually made of stainless steel. During installation, a steel-aluminum joint is required to connect the heat exchange core and the shell, significantly increasing labor costs. Furthermore, the steel-aluminum joint connection between the heat exchange core and the shell is prone to stress failure due to the material difference at both ends, especially when temperature and structural strength changes occur. Additionally, the complex structure between the heat exchange core and the outer shell increases the difficulty of cleaning and maintenance later on. Therefore, there is an urgent need for a heat exchanger with a simple structure and reliable strength. Utility Model Content

[0010] The purpose of this invention is to provide a subcooled liquid oxygen heat exchanger for cryogenic liquid rockets, in order to solve the problems existing in the prior art.

[0011] To achieve the above objectives, this utility model provides the following solution:

[0012] This utility model provides a subcooled liquid oxygen heat exchanger for cryogenic liquid rockets, comprising a shell, a heat exchange core, and a support mechanism, wherein:

[0013] The shell is provided with a liquid nitrogen inlet and a nitrogen outlet, and the liquid nitrogen inlet and the nitrogen outlet are arranged opposite to each other;

[0014] The heat exchange core is located inside the housing, and the housing is provided with a liquid oxygen inlet and a liquid oxygen outlet, and the liquid oxygen inlet and the liquid oxygen outlet are respectively connected to the inlet and outlet of the heat exchange core;

[0015] The two ends of the support mechanism are respectively connected to the outer shell of the heat exchange core and the inner wall of the shell;

[0016] The shell, the heat exchange core, and the support mechanism are all made of aluminum.

[0017] According to one embodiment of the present invention, the heat exchange core is a plate-fin heat exchanger.

[0018] According to one embodiment of the present invention, the shell is a multi-layer structure, and an insulation layer is provided between any two adjacent layers of the multi-layer shell.

[0019] According to one embodiment of the present invention, the insulation layer is a polyurethane foam layer.

[0020] According to one embodiment of the present invention, the support mechanism includes a support column, and the two ends of the support column are respectively connected to the outer shell of the heat exchange core and the inner wall of the shell.

[0021] According to one embodiment of the present invention, the number of the support columns is several, and the several support columns are arranged sequentially along the circumference of the housing.

[0022] According to one embodiment of the present invention, the housing is provided with a liquid nitrogen outlet, which is located on the same side as the liquid nitrogen inlet.

[0023] According to one embodiment of the present invention, a connecting pipe is installed in each of the liquid nitrogen inlet, the liquid nitrogen outlet, the liquid oxygen inlet, the nitrogen outlet, and the liquid oxygen outlet, and the two ends of the connecting pipe are located inside the shell and outside the shell, respectively; the connecting pipe installed in the liquid oxygen inlet is connected to the inlet of the heat exchange core at one end of the shell, and the connecting pipe installed in the liquid oxygen outlet is connected to the outlet of the heat exchange core at one end of the shell.

[0024] According to one embodiment of the present invention, corrugated compensators are installed in both the connecting pipe installed in the liquid oxygen inlet and the connecting pipe installed in the liquid oxygen outlet.

[0025] According to one embodiment of the present invention, the connecting pipe is made of aluminum.

[0026] This utility model has at least the following technical effects:

[0027] This invention provides a subcooled liquid oxygen heat exchanger for cryogenic liquid rockets. By setting up a support mechanism, the heat exchange core and the shell can be connected. The structure is simple and does not require a complex structure, thus reducing the labor cost during installation.

[0028] The heat exchange core and shell of this invention are both made of aluminum, eliminating the need for a steel-aluminum joint during installation and further reducing labor costs. The aluminum construction of both the heat exchange core and shell also avoids stress damage caused by differences in material properties, ensuring it won't affect subsequent rocket launch missions, improving the overall structural strength of the heat exchanger, and guaranteeing its strength and reliability.

[0029] Furthermore, the simple structure between the heat exchange core and the shell reduces the difficulty of cleaning and maintenance in the later stages, and also reduces the labor costs of cleaning and maintaining the heat exchanger. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a frontal view of the overall internal structure of this utility model;

[0032] Figure 2 This is a bottom view of the overall internal structure of this utility model;

[0033] The components are: 1. Liquid nitrogen inlet; 2. Liquid nitrogen outlet; 3. Heat exchange core; 4. Support column; 5. Shell; 6. Liquid oxygen inlet; 7. Nitrogen outlet; 8. Liquid oxygen outlet. Detailed Implementation

[0034] The features and exemplary embodiments of various aspects of this utility model will be described in detail below. To make the objectives, technical solutions, and advantages of this utility model clearer, the following detailed description is provided in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only configured to explain this utility model and to exemplarily illustrate the principles of this utility model, and are not configured to limit this utility model. In addition, the structural components in the drawings are not necessarily drawn to scale. For example, the dimensions of some structural components or regions in the drawings may be enlarged for other structural components or regions to aid in the understanding of the embodiments of this utility model.

[0035] The directional terms used in the following description refer to the directions shown in the figures and are not intended to limit the specific structure of the embodiments of this utility model. In the description of this utility model, it should be noted that, unless otherwise stated, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0036] Furthermore, the terms "comprising," "including," "having," or any other variations thereof are intended to cover non-exclusive inclusion, such that a structure or component that includes a list of elements includes not only those elements but also other structural elements that are not expressly listed or inherent to the structure or component. Without further limitations, an element defined by the phrase "comprising..." does not exclude the presence of other identical elements in the article or apparatus that includes the element.

[0037] Spatial relation terms such as "below," "under," "under," "low," "above," "on," and "high" are used for descriptive convenience to explain the positioning of one element relative to a second element, indicating that these terms are intended to cover different orientations of the device, in addition to those different from those shown in the figure. Furthermore, phrases such as "one element on / below another element" can indicate that two elements are in direct contact, or that there are other elements between the two elements. In addition, terms such as "first" and "second" are also used to describe individual elements, areas, parts, etc., without specifically indicating order or sequence, and should not be considered restrictive. Similar terms are used throughout the description to represent similar elements.

[0038] In the following description of this utility model, the terms "rocket," "launch vehicle," "spacecraft," "space launch vehicle," or "missile" may be used in certain scenarios for ease of description, and their connotations are not limited to the specific terms used. Generally, the launch vehicle of this utility model includes space launch vehicles and rockets used to launch satellites, spacecraft, or other probes, as well as various missiles, rockets, and other weapons used to launch military payloads, and similar products capable of sending payloads into the air. Those skilled in the art, when interpreting the above specific terms, should not limit the launch vehicle to only one of space launch vehicles, rockets, or missiles based on the specific terms used in the description, thereby narrowing the scope of protection of this utility model.

[0039] For those skilled in the art, this invention can be implemented without some of these specific details. The following description of the embodiments is merely intended to provide a better understanding of the invention by illustrating examples.

[0040] This invention provides a subcooled liquid oxygen heat exchanger for use in cryogenic liquid rockets, with reference to... Figure 1 It includes a shell 5, a heat exchange core 3, and a support mechanism, wherein:

[0041] The housing 5 is provided with a liquid nitrogen inlet 1 and a nitrogen outlet 7, which are arranged opposite to each other.

[0042] In this embodiment, refer to Figure 1 The shell 5 has a capsule-shaped structure, with the liquid nitrogen inlet 1 and the nitrogen outlet 7 respectively opened on two arc-shaped surfaces of the shell 5, preferably at the center of the arc-shaped surfaces.

[0043] The heat exchange core 3 is located inside the shell 5. The shell 5 is provided with a liquid oxygen inlet 6 and a liquid oxygen outlet 8, and the liquid oxygen inlet 6 and the liquid oxygen outlet 8 are respectively connected to the inlet and outlet of the heat exchange core 3.

[0044] In this embodiment, refer to Figure 1 The liquid oxygen inlet 6 can be positioned at a height higher than the liquid oxygen outlet 8, with the liquid oxygen flowing in a "top-in, bottom-out" manner. However, those skilled in the art can adjust the liquid oxygen flow pattern to "bottom-in, top-out" depending on the actual situation. Furthermore, those skilled in the art can adjust the relative height of the liquid oxygen inlet 6 and the liquid oxygen outlet 8 to achieve either a "bottom-in, bottom-out" or "top-in, top-out" flow pattern, without any particular limitation here.

[0045] The heat exchange core 3 is preferably a plate-fin heat exchanger. A plate-fin heat exchanger is mainly composed of a shell, baffles, fins, seals, and guide vanes, which are brazed together. Hot and cold fluids can flow through different channels within the plate-fin heat exchanger, and heat can be transferred through the baffles and fins. The guide vanes are typically located at the fluid inlet and outlet (i.e., the inlet and outlet of the heat exchange core 3) and are used to guide the fluid to a uniform distribution, avoid dead zones and short circuits, and ensure normal heat exchange operation. The above content is all prior art known to those skilled in the art and will not be elaborated further here.

[0046] The two ends of the support mechanism are connected to the outer shell of the heat exchange core 3 and the inner wall of the shell 5, respectively, preferably by welding.

[0047] The shell 5, the heat exchange core 3, and the support mechanism are all made of aluminum, a material known to those skilled in the art.

[0048] When installing the heat exchanger of this utility model, since the shell 5, heat exchange core 3 and support mechanism are all made of aluminum, there is no need to use traditional steel-aluminum joints. Therefore, there is no need for high temperature control requirements during welding, which reduces the difficulty of welding when installing the heat exchanger and thus reduces the labor cost of installing the heat exchanger.

[0049] The heat exchanger of this invention uses aluminum materials throughout, avoiding the use of traditional steel-aluminum joints at the connection points of various components. This prevents the formation of intermetallic compounds (Al3Fe). Furthermore, since all components have the same coefficient of thermal expansion, it avoids breakage due to differences in thermal stress after connection, thus improving the overall structural strength and reliability of the heat exchanger and the reliability of subsequent launch missions.

[0050] Furthermore, steel-aluminum joints are expensive and difficult to mass-produce. Using all-aluminum materials eliminates the need for steel-aluminum joints between components, significantly reducing the production cost of the heat exchanger. Moreover, by using all-aluminum materials, the weight of the heat exchanger in this invention can be reduced by approximately 35% compared to traditional heat exchangers, thus reducing the forces exerted on the supporting structure of the heat exchanger in the launch site refueling system.

[0051] In this embodiment, the subcooling medium is liquid oxygen, and the subcoolant is liquid nitrogen. Those skilled in the art can also use other known subcoolants and subcooling media suitable for plate-fin heat exchangers, depending on the actual situation; no particular limitation is made here. Furthermore, the heat exchanger of this invention can also be applied to cross-flow, counter-flow, and reverse-cross-flow internal fluid flow patterns.

[0052] This invention, through the design of a support mechanism, allows for a simple connection between the heat exchanger core and the shell, eliminating the need for complex structures and reducing the difficulty and labor costs associated with heat exchanger installation. Furthermore, the simple structure between the heat exchanger core and shell reduces the difficulty of subsequent cleaning and maintenance, thereby lowering labor costs for these tasks.

[0053] According to one embodiment of the present invention, the shell 5 has a multi-layer structure, and an insulation layer (not shown in the figure) is provided between any two adjacent layers of the multi-layer shell 5.

[0054] In this embodiment, the shell 5 has a two-layer structure, with an insulation layer located between the two shell layers. The insulation layer is preferably made of polyurethane foam, a material known to those skilled in the art. Polyurethane foam has good insulation properties and a low thermal conductivity, which can further improve the insulation performance of the shell 5.

[0055] According to one embodiment of the present invention, referring to Figure 1 The support mechanism includes support columns 4, with both ends of the support columns 4 connected to the outer shell of the heat exchange core 3 and the inner wall of the shell 5, respectively. The connection method is preferably welding. There are several support columns 4, and these support columns 4 are arranged sequentially along the circumference of the shell 5 inside the shell 5.

[0056] In this embodiment, refer to Figure 1 and Figure 2 The number of support columns 4 is preferably eight and divided into upper and lower layers. The upper and lower layers each have four support columns 4 arranged sequentially along the circumference of the shell 5, and the two adjacent support columns 4 in each layer are arranged perpendicularly. The four support columns 4 in the upper layer and the four support columns 4 in the lower layer are respectively located in the same vertical plane.

[0057] In one embodiment of this utility model, the connection between the shell 5 and the heat exchange core 3 can be achieved using four support columns 4, resulting in a simple structure and reducing the difficulty and labor costs during installation. (Refer to...) Figure 2In the heat exchanger of this application embodiment, there is a large space between the shell 5 and the heat exchange core 3. Therefore, when it is necessary to clean and maintain the heat exchange core and the shell in the later stage, the staff can also make use of the large space between the heat exchange core and the shell and clean and maintain the heat exchange core and the shell in the space between the heat exchange core and the shell, thereby reducing the difficulty of later cleaning and maintenance and reducing the labor cost of later cleaning and maintenance of the heat exchanger.

[0058] According to one embodiment of the present invention, referring to Figure 1 and Figure 2 The shell 5 is provided with a liquid nitrogen outlet 2, which is located on one side of the liquid nitrogen inlet 1.

[0059] In this embodiment, the liquid nitrogen outlet 2 is located on the arc-shaped surface of the shell 5 on one side of the liquid nitrogen inlet 1, and is disposed adjacent to the liquid nitrogen inlet 1.

[0060] When in use, if too much liquid nitrogen is added into the liquid nitrogen inlet 1, the excess liquid nitrogen can flow out through the liquid nitrogen outlet 2, thereby further ensuring the smooth operation of the liquid oxygen supercooling.

[0061] According to one embodiment of this utility model, connecting pipes are installed in the liquid nitrogen inlet 1, liquid nitrogen outlet 2, liquid oxygen inlet 6, nitrogen outlet 7, and liquid oxygen outlet 8. Preferably, the connecting pipes are installed by welding. Preferably, the connecting pipes are made of aluminum, and their two ends are located inside and outside the housing 5, respectively. The connecting pipe installed in the liquid oxygen inlet 6 connects to the inlet of the heat exchange core 3 at one end of the housing 5, and the connecting pipe installed in the liquid oxygen outlet 8 connects to the outlet of the heat exchange core 3 at one end of the housing 5. Preferably, the connecting pipes are connected to the heat exchange core 3 by welding.

[0062] The connecting pipes ensure the smooth flow of liquid nitrogen, liquid oxygen, and nitrogen gas. Furthermore, since these connecting pipes are also made of aluminum, a material known for its excellent thermal conductivity (as is known in the art), and because the connecting pipes installed within the liquid oxygen inlet 6 are connected to the heat exchange core 3, their walls can also transfer the temperature within the heat exchange core 3. Specifically, before liquid oxygen flows into the heat exchange core 3, it comes into contact with the temperature of the connecting pipe walls, thus pre-cooling it and further enhancing the heat exchange with the liquid oxygen, increasing the heat exchanger's efficiency. In addition, pre-cooling can reduce the amount of liquid oxygen used, lowering the cost of subsequent rocket launches.

[0063] According to one embodiment of the present invention, both the connecting pipe installed in the liquid oxygen inlet 6 and the connecting pipe installed in the liquid oxygen outlet 8 are preferably vacuum pipes known in the art, and both are equipped with corrugated compensators (not shown in the figure). The installation method is preferably a detachable installation method, such as bolt connection known in the art.

[0064] Corrugated compensators are existing technology known to those skilled in the art. They can absorb length changes in pipelines caused by thermal expansion and contraction due to their expandable and deformable characteristics. When liquid oxygen passes through a connecting pipeline, causing length changes due to thermal expansion and contraction, the corrugated compensator can be compressed to accommodate the elongation of the connecting pipeline, or stretched to compensate for the shortening. This alleviates thermal stress inside the connecting pipeline, effectively preventing deformation and rupture due to excessive thermal stress, and ensuring the safe and stable operation of the heat exchanger.

[0065] The working process of this utility model will be briefly described below with reference to the above embodiments:

[0066] In use, firstly, liquid nitrogen is introduced into the connecting pipe of liquid nitrogen inlet 1 and stored inside the shell 5. The latent heat of vaporization of liquid nitrogen itself is used to participate in heat exchange, thereby cooling the heat exchange core 3.

[0067] After participating in the heat exchange, the liquid nitrogen absorbs heat and turns into nitrogen gas, which is then discharged through the connecting pipe at nitrogen outlet 7. During the heat exchange process, if too much liquid nitrogen is added, it can be discharged through the connecting pipe at liquid nitrogen outlet 2; if too little liquid nitrogen is added, it can be replenished through the connecting pipe at liquid nitrogen inlet 1.

[0068] Then, liquid oxygen that needs to be subcooled is introduced into the connecting pipe of liquid oxygen inlet 6. The liquid oxygen will enter the inlet of heat exchange core 3 (i.e. plate-fin heat exchanger) through the connecting pipe, and be dispersed to various parts of its interior by the guide vanes at the inlet of the plate-fin heat exchanger. Then, it will exchange heat with the liquid nitrogen in the shell 5 through the fins inside the plate-fin heat exchanger, thereby completing the subcooling treatment of liquid oxygen.

[0069] Finally, the supercooled liquid oxygen will flow out through the connecting pipe of liquid oxygen outlet 8 and be used to fuel the rocket body to complete the subsequent combustion and propulsion of the rocket engine.

[0070] The above embodiments of this utility model can be combined with each other and have corresponding technical effects.

[0071] The above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A subcooled liquid oxygen heat exchanger for use in cryogenic liquid rockets, characterized in that, It includes a shell (5), a heat exchange core (3), and a support mechanism, wherein: The housing (5) is provided with a liquid nitrogen inlet (1) and a nitrogen outlet (7), and the liquid nitrogen inlet (1) and the nitrogen outlet (7) are arranged opposite to each other; The heat exchange core (3) is located inside the shell (5). The shell (5) is provided with a liquid oxygen inlet (6) and a liquid oxygen outlet (8), and the liquid oxygen inlet (6) and the liquid oxygen outlet (8) are respectively connected to the inlet and outlet of the heat exchange core (3). The two ends of the support mechanism are respectively connected to the outer shell of the heat exchange core (3) and the inner wall of the shell (5); The shell (5), the heat exchange core (3) and the support mechanism are all made of aluminum and are not connected by a steel-aluminum joint; The shell (5) has a capsule-shaped structure, and the liquid nitrogen inlet (1) and the nitrogen outlet (7) are respectively opened at the center of the two arc-shaped surfaces of the shell (5); The support mechanism includes support columns (4), and the two ends of the support columns (4) are respectively connected to the outer shell of the heat exchange core (3) and the inner wall of the shell (5); there are eight support columns (4), and the eight support columns (4) are arranged sequentially along the circumference of the shell (5) and divided into upper and lower layers. The two adjacent support columns (4) in each layer are arranged vertically, and the four support columns (4) in the upper layer and the four support columns (4) in the lower layer are respectively located in the same vertical plane. The shell (5) is provided with a liquid nitrogen outlet (2), which is located on one side of the liquid nitrogen inlet (1); the liquid nitrogen inlet (1), the liquid nitrogen outlet (2), the liquid oxygen inlet (6), the nitrogen outlet (7) and the liquid oxygen outlet (8) are all equipped with connecting pipes, with the two ends of the connecting pipes located inside the shell (5) and outside the shell (5) respectively; the connecting pipe installed in the liquid oxygen inlet (6) is connected to the inlet of the heat exchange core (3) at one end of the shell (5), and the connecting pipe installed in the liquid oxygen outlet (8) is connected to the outlet of the heat exchange core (3) at one end of the shell (5); The connecting pipe is made of aluminum. The shell (5) is a multi-layer structure, and an insulation layer is provided between any two adjacent layers of the multi-layer shell (5); The shell (5) has a two-layer structure, and the insulation layer is located between the two-layer shell (5); The insulation layer is a polyurethane foam layer; Both the connecting pipe installed in the liquid oxygen inlet (6) and the connecting pipe installed in the liquid oxygen outlet (8) are equipped with corrugated compensators, and both are vacuum pipes.

2. The subcooled liquid oxygen heat exchanger for cryogenic liquid rockets according to claim 1, characterized in that, The heat exchange core (3) is a plate-fin heat exchanger.

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