Low altitude aircraft air conditioning condenser

Abstract

The application relates to the technical field of air conditioning systems, in particular to a low-altitude aircraft air conditioner condenser which comprises a mixed-flow fan, a heat exchange core assembly and a refrigerant pipeline mechanism, the heat exchange core assembly comprises at least two parallelly arranged heat exchange cores, the mixed-flow fan is arranged above the heat exchange core assembly, the air suction port of the mixed-flow fan is communicated with the air inlet end of the heat exchange core assembly, so as to form a forced air inlet channel from the side air inlet port to the heat exchange core assembly through the fan, the refrigerant pipeline mechanism is arranged between the adjacent heat exchange cores, and the air flow direction of the heat exchange core assembly and the flow direction of the refrigerant in the refrigerant pipeline mechanism are countercurrently arranged. The application has the advantages that the stable and controllable air inlet flow and pressure can be maintained, the airflow distribution problem caused by the traditional fan is avoided, the refrigerant preliminarily cooled is subjected to heat exchange with the air preliminarily heated, the average temperature difference in the whole heat exchange process is maximized, and the overall heat exchange efficiency of the condenser is significantly improved.

Description

Technical Field

[0001] This application relates to the technical field of air conditioning systems, and in particular to an air conditioning condenser for low-altitude aircraft. Background Technology

[0002] In the field of low-altitude aircraft air conditioning systems, with the development of technology and the increasingly widespread application of low-altitude aircraft, the requirements for the performance and layout of their air conditioning systems are gradually increasing. An efficient and reliable air conditioning system is crucial for ensuring the internal environment of the aircraft, maintaining normal equipment operation, and improving the overall performance of the aircraft system. A well-designed low-altitude aircraft air conditioning system can extend equipment lifespan, reduce the failure rate, and thus improve the safety and reliability of the aircraft.

[0003] In previous low-altitude aircraft air conditioning systems, the conventional approach to designing and configuring condenser components was to use a traditional single-core condenser structure and an axial flow fan. Regarding the air intake method, a direct-intake mode was generally preferred. This design and selection were based on the structural characteristics and aerodynamic principles of traditional aircraft. Single-core condensers were simple in structure and had relatively mature manufacturing processes, making them a commonly used solution under the technological conditions at the time. Axial flow fans, due to their structural characteristics, could provide some airflow support under high air volume conditions, and were therefore widely used in traditional air conditioning systems. The direct-intake mode was chosen because it directly utilizes the oncoming airflow during aircraft flight, reducing additional power consumption.

[0004] However, for eVTOL aircraft, the traditional front-facing air intake mode mentioned above cannot meet the required air volume. At the same time, when combined with the single-core condenser structure, the insufficient air volume cannot meet the heat exchange requirements, resulting in low heat exchange efficiency. Poor heat exchange can easily cause the aircraft's heat to not be dissipated in time, leading to increased energy consumption or damage to parts. Summary of the Invention

[0005] To meet the airflow requirements of eVTOL low-altitude aircraft and improve heat exchange efficiency, the purpose of this application is to provide a low-altitude aircraft air conditioning condenser, employing the following technical solution: This includes mixed-flow fans, heat exchanger core components, and refrigerant piping systems; The heat exchange core assembly includes at least two heat exchange cores arranged side by side; The mixed-flow fan is positioned above the heat exchange core assembly, and the air inlet of the mixed-flow fan is connected to the air inlet of the heat exchange core assembly to form a forced air intake channel from the side air inlet through the fan to the heat exchange core assembly. The refrigerant piping system is arranged between adjacent heat exchange cores, and the airflow direction of the heat exchange core assembly is arranged in the opposite direction to the refrigerant flow direction within the refrigerant piping system.

[0006] By adopting the above technical solutions, the design of the forced air intake channel ensures that stable and controllable airflow and pressure can still be maintained under the conditions of forward airflow or complex incoming flow that low-altitude aircraft may encounter. Placing the mixed-flow fan above the heat exchange core assembly can form a stable negative pressure zone at the fan inlet, which promotes the uniform and smooth entry of external air and covers the entire windward surface of the heat exchange core. This effectively avoids the airflow "dead zone" and uneven distribution problems that may be generated by traditional blower fans. Furthermore, the air and refrigerant are arranged in a counter-current manner, which ensures that the high-temperature refrigerant always encounters the lowest temperature incoming air, while the pre-cooled refrigerant exchanges heat with the preheated air, maximizing the average temperature difference in the entire heat exchange process, thereby significantly improving the overall heat exchange efficiency and capacity of the condenser.

[0007] Optionally, the outer wall of the casing of the mixed-flow fan is provided with annular reinforcing ribs, which are distributed along the fan axis and rigidly connected to the frame of the heat exchange core assembly.

[0008] By adopting the above technical solutions, the overall structural rigidity and strength of the condenser are significantly enhanced. This integrated design can effectively resist the severe vibration and impact loads generated by low-altitude aircraft during takeoff, landing, and maneuvering, prevent relative displacement or loosening of the connection between the fan and the heat exchange core due to different vibration frequencies, ensure structural reliability and sealing under long-term operation, and also help reduce operating noise and extend the service life of the equipment.

[0009] Optionally, the at least two heat exchange cores are spaced apart along their arrangement direction to form a first core layer and a second core layer, which are fixed together by a frame to form an integral condensation unit.

[0010] By adopting the above technical solutions, the effective heat exchange area is significantly increased within a limited space, thereby improving the heat exchange capacity per unit volume and meeting the stringent requirements of aircraft for equipment compactness and lightweighting. By fixing multiple cores into a whole through the frame, the installation structure is simplified, the degree of modularity is improved, and it is convenient to carry out overall loading, unloading and maintenance on the aircraft, while ensuring the stability of the relative positions between the cores.

[0011] Optionally, the frame is provided with vertical support ribs that extend along the airflow direction and intersect with the arrangement direction of the heat exchange cores, forming a limiting structure for the first core layer and the second core layer.

[0012] By adopting the above technical solution, strong internal support and restraint are provided for the multi-layer heat exchange core. These stiffeners can effectively resist the lateral force and bending stress generated by airflow pressure and flight vibration on the core, preventing deformation, misalignment or fin collapse of the core layer during long-term operation, thereby maintaining the airflow channel shape and size specified in the design and ensuring the stability and durability of heat exchange performance.

[0013] Optionally, both the first core layer and the second core layer adopt a corrugated fin structure, wherein the extension direction of the corrugated fins forms an acute angle with the airflow direction.

[0014] By adopting the above technical solution, the corrugated shape can continuously cut and disturb the air boundary layer, enhancing airflow turbulence and thus strengthening the convective heat transfer coefficient on the air side. Simultaneously, the acute-angle arrangement lengthens the airflow path and causes controllable deflection as it passes through the fin gaps, further increasing the contact and heat exchange time between the air and the fins. Without significantly increasing wind resistance, this effectively improves the heat transfer efficiency of the fins, achieving a good balance between performance and energy consumption.

[0015] Optionally, the refrigerant piping system includes a distributor pipe and a collector pipe. The distributor pipe is connected to the first core layer, and the collector pipe is connected to the second core layer, so that the refrigerant flow direction is opposite to the air flow direction.

[0016] By adopting the above technical solution, a specific and reliable fluid path implementation scheme is provided for the countercurrent principle. This pipeline design ensures that the refrigerant can flow through each heat exchange core layer in a predetermined path sequence completely opposite to the air flow direction, so that the theoretical advantages of countercurrent heat exchange can be fully realized in the complex multi-layer core structure, and the thermodynamic performance of the entire condensation process is optimized.

[0017] Optionally, it also includes a guide plate assembly, which is disposed on the air inlet side of the heat exchange core assembly and connected to the air intake of the mixed flow fan. The guide plate assembly has guide grooves for rectifying and splitting the airflow.

[0018] By adopting the above technical solution, the problem of airflow transition and distribution between the circular air intake of the fan and the windward surface of the rectangular heat exchange core is solved. The guide vane assembly can effectively rectify and guide the high-speed rotating or uneven airflow output by the fan, smoothly and evenly distributing it to various areas of the heat exchange core assembly. This avoids problems such as uneven heat exchange, increased wind resistance, and even noise caused by airflow directly impacting local areas of the core, thereby improving the uniformity and stability of heat exchange efficiency.

[0019] Optionally, the guide plate assembly includes multiple stacked metal plates, with airflow channels formed between adjacent metal plates that match the orientation of the fins of the heat exchange core assembly.

[0020] By adopting the above technical solution, a specific and efficient airflow guidance implementation scheme is provided. This structure can be precisely matched and designed according to the spacing and orientation of the downstream heat exchange core fins to form multiple parallel micro-guide channels. This allows the airflow to be "pre-processed" to be in a state coordinated with the fin direction before entering the fin array, minimizing airflow turning losses and vortex generation, and achieving extremely low-loss airflow transfer and distribution.

[0021] Optionally, the mixed-flow fan is a mixed-flow fan in which the impeller blades are arranged radially inclined to balance airflow velocity and pressure output.

[0022] By adopting the above technical solution, the advantages of high flow rate of axial fans and high pressure characteristics of centrifugal fans are combined. This design enables the fan to provide sufficient static pressure to overcome the wind resistance of the heat exchange core and a large volumetric flow rate to maintain condensation, even under the space constraints commonly found in aircraft air conditioning systems. This achieves better airflow-pressure matching performance within a compact installation space, ensuring that the condenser operates efficiently and reliably under various operating conditions.

[0023] In summary, this application includes at least one of the following beneficial technical effects: 1. The forced air intake channel design ensures that stable and controllable airflow and pressure can be maintained even under forward airflow or complex incoming flow conditions that low-altitude aircraft may encounter. Placing the mixed-flow fan above the heat exchange core assembly creates a stable negative pressure zone at the fan inlet, promoting the uniform and smooth entry of external air and covering the entire windward surface of the heat exchange core. This effectively avoids the airflow "dead zones" and uneven distribution problems that may occur with traditional blower fans. Furthermore, the air and refrigerant are arranged in a counter-current manner, which ensures that the high-temperature refrigerant always encounters the lowest-temperature incoming air, while the pre-cooled refrigerant exchanges heat with the preheated air, maximizing the average temperature difference in the entire heat exchange process and thus significantly improving the overall heat exchange efficiency and capacity of the condenser. 2. The modular core design with layered parallel arrangement increases the heat exchange area in a limited space. Combined with corrugated fins at a specific angle and a carefully designed baffle assembly, it effectively enhances airflow disturbance and achieves uniform airflow distribution, further improving heat exchange uniformity and fin efficiency. 3. The integrated reinforcement design, including ring-shaped reinforcing ribs, rigid connection frame, and internal support ribs, significantly improves the rigidity and vibration and shock resistance of the overall module, ensuring long-term operational reliability under complex low-altitude flight conditions. It also meets the stringent requirements of aircraft for compact, lightweight, and easy-to-maintain equipment. Attached Figure Description

[0024] Figure 1This is a top-down view of the overall structure of a low-altitude aircraft. Figure 2 yes Figure 1 A schematic diagram of the cross-sectional structure of section AA in the middle; Figure 3 yes Figure 2 An enlarged schematic diagram of part A in the middle; In the picture, 1. Mixed-flow fan; 2. Heat exchange core assembly; 21. First core layer; 22. Second core layer; 3. Refrigerant piping system; 4. Shell. Detailed Implementation

[0025] The following is in conjunction with the appendix Figure 1 -Appendix Figure 3 This application will be described in further detail below.

[0026] A low-altitude aircraft air conditioning condenser, reference Figures 1-3 The condenser comprises a mixed-flow fan 1, a heat exchange core assembly 2, a refrigerant piping system 3, and a baffle plate assembly. Since the low-altitude aircraft flies upwards, both the mixed-flow fan 1 and the heat exchange core assembly 2 are housed within the casing 4. The mixed-flow fan 1 is positioned above the heat exchange core assembly 2, with its intake port connected to the air inlet of the heat exchange core assembly 2, forming a forced air intake channel from the side air inlet through the fan to the heat exchange core assembly 2. The baffle plate assembly is located on the air inlet side of the heat exchange core assembly 2 and connects to the intake port of the mixed-flow fan 1. The refrigerant piping system 3 is positioned between adjacent heat exchange cores, with the airflow direction of the heat exchange core assembly 2 and the refrigerant flow direction within the refrigerant piping system 3 arranged in a counter-current configuration. This arrangement allows the condenser to adapt to the side air intake of the low-altitude aircraft and improves heat exchange efficiency through counter-current heat exchange.

[0027] Specifically, the mixed-flow fan 1 includes a fan casing 4 and an impeller. The fan casing 4 is characterized by annular reinforcing ribs on its outer wall, distributed along the fan's axial direction. These annular reinforcing ribs can be welded or integrally formed onto the fan casing 4; their function is to enhance the strength of the fan casing 4, making it more stable.

[0028] Optionally, the reinforcing structure of the mixed-flow fan 1 uses spiral reinforcing ribs instead of annular reinforcing ribs. Spiral reinforcing ribs also enhance the strength of the fan casing 4; they are wound around the outer wall of the fan casing 4 in a spiral pattern. The spiral reinforcing ribs can be installed on the fan casing 4 by casting or winding. Compared to annular reinforcing ribs, spiral reinforcing ribs, while enhancing the strength of the fan casing 4, may cause less interference with airflow.

[0029] While ensuring the strength of the mixed-flow fan 1, the interference with airflow is reduced, enabling the fan to provide forced air intake to the heat exchange core assembly 2 more efficiently, further improving the overall performance of the condenser. This is an optimization and improvement of the existing technology.

[0030] Similarly, the impeller blades can also adopt other shapes and tilt angles, as long as they can meet the requirements of balancing airflow velocity and pressure output. The impeller blades are arranged radially at an angle, which can balance airflow velocity and pressure output. The impeller can be made of lightweight materials such as aluminum alloy to reduce the weight of the fan. The mixed-flow fan 1 is rigidly connected to the frame of the heat exchange core assembly 2 through annular reinforcing ribs, for example, by bolt connection. This ensures the connection stability between the fan and the heat exchange core assembly 2, enabling the fan to stably provide forced airflow to the heat exchange core assembly 2.

[0031] Specifically, refer to Figure 2 The heat exchange core assembly 2 includes at least two heat exchange cores arranged side by side. These heat exchange cores are spaced apart along their arrangement direction to form a first core layer 21 and a second core layer 22, which are fixed together by a frame to form an integral condensation unit. Vertical support ribs are provided within the frame, extending along the airflow direction and intersecting the arrangement direction of the heat exchange cores to form a limiting structure for the first core layer 21 and the second core layer 22.

[0032] The frame can be made of metal, possessing sufficient strength and rigidity to protect the internal heat exchange core. Support ribs can be fixed within the frame by welding or bolting, preventing displacement of the heat exchange core under airflow and ensuring its stability. Both the first core layer 21 and the second core layer 22 employ corrugated fin structures, with the extension direction of the corrugated fins forming an acute angle with the airflow direction. The corrugated fins increase the contact area between the air and the heat exchange core, improving heat exchange efficiency. The corrugated fins can be made of materials with good thermal conductivity, such as copper or aluminum. For replaceable features, other fin shapes, such as needle-shaped fins, can also be used. This combination of heat exchange cores, through a double-layer arrangement, reduces the overall space required in the X and Z directions, and, with the restraint of the support ribs, ensures stable heat exchange operation.

[0033] Specifically, the refrigerant piping structure 3 includes a distribution pipe and a collection pipe. The distribution pipe is connected to the first core layer 21, and the collection pipe is connected to the second core layer 22. This connection method allows the refrigerant flow direction to be counter-current to the air flow direction. The distribution pipe and the collection pipe can be made of materials with good thermal conductivity, such as copper pipes. The function of the distribution pipe is to evenly distribute the refrigerant into each heat exchange channel of the first core layer 21, while the collection pipe collects the refrigerant after heat exchange in the second core layer 22. Through this counter-current heat exchange method, the temperature difference between the refrigerant and the air can be maintained at a large level throughout the heat exchange process, thereby improving the heat exchange efficiency.

[0034] Specifically, the baffle assembly comprises multiple stacked metal sheets. Airflow channels are formed between adjacent metal sheets, matching the fin orientation of the heat exchange core assembly 2. The metal sheets can be made of corrosion-resistant materials such as stainless steel. The baffle assembly has guide channels for rectifying and distributing the airflow, which can be formed on the metal sheets through processes such as stamping. When the airflow blown by the mixed-flow fan 1 enters the baffle assembly, the guide channels rectify the airflow, making it enter the heat exchange core assembly 2 more evenly, while also distributing the airflow to ensure better contact between the airflow and the fins of the heat exchange core assembly 2, thereby improving the heat exchange effect.

[0035] Optionally, the double-layered stacked condenser core assembly can be replaced with two sets of condenser core modules arranged side-by-side. The mixed-flow fan 1 is located on the windward side of the two sets of condenser core modules and is directly connected to the side air inlets. This arrangement may be more suitable for the structural layout of some low-altitude aircraft, for example, when there is more space available in the lateral direction at the front of the aircraft, the side-by-side condenser core modules can better adapt to this spatial characteristic. The two sets of condenser core modules are also fixed by a frame, which can adopt a structure similar to that in the above embodiment, with supporting ribs to ensure the stability of the modules. The refrigerant piping mechanism 3 still uses a distributor pipe and a collector pipe, which are connected to the two sets of condenser core modules respectively to achieve counter-current heat exchange. The structure and working principle of the mixed-flow fan 1 are the same as in the above embodiment; it blows the airflow obtained from the side air inlets directly to the two sets of condenser core modules to achieve forced heat exchange.

[0036] The air conditioning condenser assembly structure for low-altitude aircraft offers a novel spatial arrangement by replacing the double-layered stacked condenser core assembly with side-by-side condenser core modules, providing a better fit for the structural characteristics of different low-altitude aircraft. While meeting the requirements of non-direct airflow intake in low-altitude aircraft and improving heat exchange efficiency, it increases the flexibility and adaptability of the assembly structure, further expanding its application range in various types of low-altitude aircraft.

[0037] With the rapid development of low-altitude aircraft (including electric vertical takeoff and landing aircraft, drones, and light sport aircraft), their airborne air conditioning systems face multiple challenges, such as extremely compact space, unique aerodynamic layout, and variable flight attitudes. Traditional condensers often adopt a frontal windward or top-mounted fan design, which is difficult to adapt to the limited headroom and non-standard air intake paths of low-altitude aircraft. In addition, during aircraft climbs and hovers, condensers are susceptible to uneven airflow impacts, leading to decreased heat exchange efficiency or even performance instability.

[0038] The above-mentioned method involves placing the mixed-flow fan 1 on the air inlet side of the heat exchange core and directly connecting it to the side air inlet of the aircraft, effectively utilizing the space on the side of the fuselage and avoiding the layout problem of crowded front-end equipment. As the low-altitude aircraft ascends, air flows rapidly downwards along its sides. The air directly below the aircraft becomes very thin due to its upward flight, resulting in reduced air pressure and a negative pressure. This pressure difference between the area directly below and the sides forces air to enter from the sides, passing through the heat exchange core at the bottom of the aircraft. Simultaneously, the mixed-flow fan 1 inside the aircraft draws in the incoming air, accelerating its flow and increasing heat exchange efficiency. The air is then blown out from the outlet next to the mixed-flow fan 1, forming a complete airflow channel. The double-layered or side-by-side heat exchange core assembly 2, along with the internal refrigerant piping system 3, continuously exchange heat with the incoming air, significantly increasing the heat exchange area within a limited volume. Combined with the support ribs and reinforced frame design, this ensures structural stability even under flight vibration conditions.

[0039] Crucially, the counter-flow refrigerant piping arrangement ensures that the high-temperature refrigerant always encounters the coldest inlet air, significantly widening the logarithmic mean temperature difference throughout the process. This improves heat exchange efficiency by 10%-15% compared to a co-flow arrangement. The baffle assembly uses precisely designed guide channels to rectify and evenly distribute the airflow, overcoming the airflow deflection problem that can easily occur with side air intakes, and ensuring that each heat exchange fin channel receives sufficient and effective airflow coverage.

[0040] It achieves three core objectives: high-efficiency heat exchange, compact space, and strong adaptability. It can also flexibly adjust the core arrangement and fan configuration according to different aircraft models, providing a reliable, efficient, and customizable condensation solution for the thermal management system of low-altitude aircraft, which helps to improve the overall energy utilization efficiency and cabin comfort.

[0041] The implementation principle of this application embodiment is as follows: the air conditioning condenser of the low-altitude aircraft draws air in from the side through a mixed-flow fan 1, introducing air into the heat exchange core assembly 2. The double-layered heat exchange core reduces space occupation, adapting to the compact space characteristics of the front end of the low-altitude aircraft. The annular reinforcing ribs of the mixed-flow fan 1 enhance the stability of the fan, and the inclined impeller blades balance airflow velocity and pressure output. The refrigerant piping mechanism 3 realizes counter-current heat exchange, improving heat exchange efficiency. The guide vane assembly rectifyes and distributes the airflow, making the air contact the heat exchange core more evenly. These designs improve upon the space arrangement problems, unsuitable air intake methods, and low heat exchange efficiency existing in conventional condenser assemblies when adapted to low-altitude aircraft, thereby improving the performance and adaptability of the low-altitude aircraft air conditioning system.

[0042] The embodiments described in this specific implementation are preferred embodiments of this application and are not intended to limit the scope of protection of this application. Identical components are represented by the same reference numerals. Therefore, all equivalent changes made to the structure, shape, and principle of this application should be covered within the scope of protection of this application.

Claims

1. A condenser for air conditioning in a low-altitude aircraft, characterized in that, It includes a mixed-flow fan (1), a heat exchange core assembly (2), and a refrigerant piping system (3); The heat exchange core assembly (2) includes at least two heat exchange cores arranged side by side; The mixed-flow fan (1) is positioned above the heat exchange core assembly (2), and the air inlet of the mixed-flow fan (1) is connected to the air inlet of the heat exchange core assembly (2) to form a forced air inlet channel from the side air inlet through the fan to the heat exchange core assembly (2). The refrigerant piping mechanism (3) is arranged between adjacent heat exchange cores, and the airflow direction of the heat exchange core assembly (2) is arranged in the opposite direction to the refrigerant flow direction in the refrigerant piping mechanism (3).

2. The air conditioning condenser for a low-altitude aircraft according to claim 1, characterized in that, The outer wall of the casing (4) of the mixed-flow fan (1) is provided with annular reinforcing ribs, which are distributed along the fan axis and rigidly connected to the frame of the heat exchange core assembly (2).

3. A low-altitude aircraft air conditioning condenser according to claim 1, characterized in that, The at least two heat exchange cores are arranged at intervals along their arrangement direction to form a first core layer (21) and a second core layer (22), which are fixed together by a frame to form an integral condensation unit.

4. A low-altitude aircraft air conditioning condenser according to claim 3, characterized in that, The frame is provided with vertical support ribs, which extend along the airflow direction and intersect with the arrangement direction of the heat exchange core, forming a limiting structure for the first core layer (21) and the second core layer (22).

5. A low-altitude aircraft air conditioning condenser according to claim 3, characterized in that, Both the first core layer (21) and the second core layer (22) adopt a corrugated fin structure, and the extension direction of the corrugated fin is at an acute angle to the airflow direction.

6. A low-altitude aircraft air conditioning condenser according to claim 3, characterized in that, The refrigerant piping system (3) includes a distribution pipe and a collection pipe. The distribution pipe is connected to the first core layer (21), and the collection pipe is connected to the second core layer (22) so that the refrigerant flow direction is opposite to the air flow direction.

7. A low-altitude aircraft air conditioning condenser according to claim 1, characterized in that, It also includes a guide plate assembly, which is disposed on the air inlet side of the heat exchange core assembly (2) and connected to the air intake of the mixed flow fan (1). The guide plate assembly has a guide groove for rectifying and splitting the airflow.

8. A low-altitude aircraft air conditioning condenser according to claim 7, characterized in that, The guide plate assembly includes multiple stacked metal plates, and an airflow channel is formed between adjacent metal plates that matches the fin orientation of the heat exchange core assembly (2).

9. A low-altitude aircraft air conditioning condenser according to claim 1, characterized in that, The mixed-flow fan (1) is a mixed-flow fan (1) whose impeller blades are arranged radially inclined to take into account both airflow speed and pressure output.

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