Aircraft propulsion assembly comprising a gas-liquid heat exchanger
阅读说明:本技术 包括气液热交换器的飞行器推进组件 (Aircraft propulsion assembly comprising a gas-liquid heat exchanger ) 是由 塞巴斯蒂安·奥里奥尔 ***-拉明·布塔勒布 文森特·吉恩-弗朗索瓦·佩龙 于 2018-04-12 设计创作,主要内容包括:本发明涉及一种飞行器推进组件(10),该推进组件包括由机舱(26)包围的涡轮发动机,该机舱包括环形的进气唇缘(30),该进气唇缘通过分别是内壁(34)和外壁(36)的两个环形壁围绕涡轮发动机延伸,至少当飞行器在飞行中时,该内壁和外壁旨在被空气流(28,40)吹扫,其特征在于,所述内壁和外部各自包括或支撑管道(42)的至少一个网络,以便形成热交换器,内壁的管道的网络具有与外壁的管道的网络的至少一个进液口串联连接的至少一个出液口,并且推进组件包括用于使液体循环的装置(46,50,52,54),该装置连接到内壁的管道的网络的至少一个进液口以向该网络供应液体,并且该装置连接到外壁的管道的网络的至少一个出液口以对液体进行回收。(The invention relates to an aircraft propulsion assembly (10) comprising a turbine engine surrounded by a nacelle (26) comprising an annular air inlet lip (30) extending around the turbine engine through two annular walls, respectively an inner wall (34) and an outer wall (36) intended to be swept by an air flow (28, 40) at least when the aircraft is in flight, characterized in that said inner and outer walls each comprise or support at least one network of pipes (42) so as to form a heat exchanger, the network of pipes of the inner wall having at least one liquid outlet connected in series with at least one liquid inlet of the network of pipes of the outer wall, and in that the propulsion assembly comprises means (46, 50, 52, 54) for circulating a liquid, connected to the at least one liquid inlet of the network of pipes of the inner wall for supplying the liquid to the network, and which is connected to at least one outlet opening of the network of pipes of the outer wall for recovering the liquid.)
1. A propulsion assembly (10) for an aircraft, comprising a turbine surrounded by a nacelle (26) comprising an annular air intake lip (30) extending around the turbine by two annular walls, respectively an inner wall (34) and an outer wall (36), which are intended to be swept by an air flow (28, 40) at least when the aircraft is in flight, characterized in that:
-the inner wall and the outer wall each comprise or support at least one network of pipes (42) intended to convey the liquid in contact with the inner wall or the outer wall so as to form an inner liquid-to-liquid heat exchanger and an outer liquid-to-liquid heat exchanger, respectively, the pipes (42) of each inner heat exchanger or outer heat exchanger being connected in parallel with each other,
-the network of tubes of the inner wall has at least one liquid outlet connected in series with at least one liquid inlet of the network of tubes of the outer wall, and
-the propulsion assembly comprises means (46, 50, 52, 54) for circulating liquid, which are connected to at least one inlet port of the network of pipes of the inner wall for supplying liquid to the network of pipes of the inner wall, and which are connected to at least one outlet port of the network of pipes of the outer wall for recovering liquid.
2. Propulsion assembly (10) according to claim 1, wherein the turbine is connected to the nacelle (26) through at least one passage of an auxiliary tubular arm (52), at least one inlet opening of the network of ducts (42) of the inner wall (34) and at least one outlet opening of the network of ducts (42) of the outer wall (36) being located substantially at the level of the arm.
3. Propulsion assembly (10) according to the previous claim, wherein the arm (52) is located at a 12 o' clock position on the dial similar to a clock.
4. Propulsion assembly (10) according to one of the preceding claims, wherein the network of ducts (42) has a substantially curved or annular shape and extends around each other.
5. The propulsion assembly (10) according to the preceding claim, wherein the network of pipes (42) is segmented and each comprises at least two sectors.
6. Propulsion assembly (10) according to one of the preceding claims, wherein at least one liquid outlet of the network of ducts (42) of the inner wall (34) is connected to at least one liquid inlet of the network of ducts (42) of the outer wall (36) by at least one collector (48).
7. Propulsion assembly (10) according to the previous claim, wherein at least one liquid outlet of the network of ducts (42) of the inner wall (34) is connected to a first inner collector and at least one liquid inlet of the network of ducts (42) of the outer wall (36) is connected to a second outer collector, the first and second collectors being connected together by one or more lines extending substantially radially with respect to the axis.
8. Propulsion assembly (10) according to one of the preceding claims, wherein the inlet openings of the network of ducts (42) of the inner wall (34) are connected to a supply ramp (46) and the outlet openings of the network of ducts of the outer wall (36) are connected to a collection ramp (50).
9. Propulsion assembly (10) according to one of the previous claims, wherein at least one metal plate (44) is mounted and fixed, for example by brazing or welding, to each of the inner wall (34) and the outer wall (36) and is shaped so as to define the network of ducts (42) corresponding to the wall.
10. Propulsion assembly (10) according to the preceding claim when depending on claim 7 or 8, wherein the collector (48) and/or the ramps (46, 50) are mounted and fixed to the inner wall (34) and the outer wall (36), for example by brazing or welding.
Technical Field
The present invention relates to an aircraft propulsion assembly comprising a gas-to-liquid heat exchanger, in particular a gas-to-oil heat exchanger.
Background
Disclosure of Invention
To this end, the invention proposes a propulsion assembly for an aircraft, comprising a turbine surrounded by a nacelle comprising an annular air intake lip extending around the turbine by two annular walls, respectively an inner wall and an outer wall, intended to be purged by an air flow at least when the aircraft is in flight, characterized in that:
-said inner and outer walls each comprise or support at least one network of pipes intended to convey a liquid in contact with said inner or outer wall, so as to form an inner and an outer gas-liquid heat exchanger, respectively, the pipes of each inner or outer heat exchanger being connected in parallel with each other,
the network of ducts of the inner wall has at least one liquid outlet which is connected in series with at least one liquid inlet of the network of ducts of the outer wall, and
the propulsion assembly comprises means for circulating liquid, which are connected to at least one liquid inlet of the network of pipes of the inner wall for supplying the network of pipes of the inner wall with liquid, and which are connected to at least one liquid outlet of the network of pipes of the outer wall for recovering the liquid.
As part of the search for new heat exchange surfaces in turbines, a cooling system for liquids such as engine oil has been developed, which is in contact with a secondary air flow and an external air flow with low aerodynamic impact. The system comprises using the inner and outer walls of the nacelle as exchange surfaces between the liquid and the air. The object of the present invention is therefore to propose a liquid circulation structure at the level of the wall of a so-called "cooled" nacelle, by optimizing the power dissipated and the pressure drop generated, as well as the on-board mass.
The propulsion assembly according to the present invention may comprise one or more of the following features taken in isolation of each other or in combination with each other:
the turbine is connected to the nacelle through at least one passage of an auxiliary tubular arm, at least one inlet opening of the network of ducts of the inner wall and at least one outlet opening of the network of ducts of the outer wall being located substantially at the level of the arm,
the arm is located at the 12 o' clock position on the clock-like dial,
-the network has a substantially curved or annular shape and extends around each other,
the networks are segmented and each comprise at least two sectors,
-each of said pipes comprises two sectors, each sector being about 180,
-the network comprises a duct extending at least partially substantially parallel to the longitudinal axis of the propulsion assembly or turbine,
-at least one liquid outlet of the network of tubes of the inner wall is connected to at least one liquid inlet of the network of tubes of the outer wall by at least one collector,
-at least one liquid outlet of the network of tubes of the inner wall is connected to a first inner collector and at least one liquid inlet of the network of tubes of the outer wall is connected to a second outer collector, the first and second collectors being connected together by one or more lines extending substantially radially with respect to the axis,
-the liquid inlets of the network of conduits of the inner wall are connected to a supply ramp and the liquid outlets of the network of conduits of the outer wall are connected to a collection ramp,
-at least one metal sheet is mounted and fixed, for example by brazing (bridge) or welding (soudage), to each of said inner and outer walls and shaped so as to define said network of ducts corresponding to the wall, and
the collectors and/or ramps are mounted and fixed to said inner and outer walls, for example by brazing or welding.
Drawings
The invention will be better understood and other details, features and advantages thereof will appear more clearly when the following description is read, by way of non-limiting example, and with reference to the accompanying drawings, in which:
figure 1 is a schematic axial section view of the propulsion assembly,
figure 2 is a very schematic axial section half view of a part of a nacelle of a propulsion assembly according to the invention,
figure 3 is an enlarged view of a detail of figure 2,
figure 4 is a schematic axial section view of a nacelle of a propulsion assembly according to the invention,
FIGS. 5 and 6 comprise block diagrams illustrating the principle of oil circulation between the inner and outer walls of the nacelle,
FIG. 7 is a graph showing the variation of the dissipated power with the flow rate at equal pressure drop during cooling of the oil under each of the principles of FIGS. 5 and 6,
FIG. 8 comprises a block diagram illustrating the principle of oil circulation maintained between the inner and outer walls of the nacelle,
figure 9 is a schematic transverse cross-sectional view of a propulsion assembly nacelle according to the invention,
figure 10 is a schematic transverse cross-sectional view of another embodiment of a propulsion assembly nacelle design according to the invention,
FIG. 11 is an enlarged view of a detail of FIG. 1 and shows the downstream end of the network of nacelles equipped with ducts, an
Figure 12 is an enlarged view of a portion of figure 11.
Detailed Description
The propulsion assembly 10 includes an engine or turbine surrounded by a nacelle.
Referring to FIG. 1, the turbine is a dual flow, twin mass turbine engine that includes, from upstream to downstream in the direction of flow of the gases, a
The rotor of the high-
A
The
As shown in fig. 1, the
Fig. 2-4 illustrate one aspect of the invention, including providing a liquid-to-gas heat exchanger, preferably a gas-to-oil heat exchanger, on the
To this end, the
The conduit may at least partially have a generally axial orientation and thus extend substantially parallel to the
Alternatively, the conduit may at least partially have an annular or circumferential general orientation extending about the
Advantageously, the
In the example shown in fig. 2 and 3, the ducts of each
The dimensions D1, D2 of the
Advantageously, the
Preferably, the oil is supplied to the
At the level of the
The assembly comprising the conduit 42 (i.e. the metal plate 44), ramp and collector is preferably welded or brazed to the respective surfaces of the
Preferably, the aim is to find the optimum among the following three parameters: vacuum thermal power, pressure drop, and mass of airborne liquid. The liquid is preferably engine oil, but a heat transfer liquid other than oil can be used to cool the engine oil through a dedicated oil/heat transfer liquid heat exchanger. The heat transfer fluid may be the liquid phase in a two-phase fluid supplied to
The study of two different surfaces, namely the
In the case of series connection (fig. 5), it is preferable to supply the
The
In the parallel case (fig. 6), the geometry of the ducts of the two walls defines the flow rate distribution between these walls. However, a phenomenon of flow rate non-uniformity may occur and it is difficult to control such distribution. In fact, the exchange between two surfaces not operating under the same conditions may cause a variation in the viscosity of the oil in the pipe. This can result in a change in the flow rate distribution between the two surfaces, which is difficult to predict throughout the flight domain.
The choice of parallel or series configuration will depend on the power/voltage drop pairs exchanged. Two flow rate regions defining the use of the structure can be distinguished (see fig. 7).
It should be noted that at a certain flow rate H, the use of a parallel configuration is more interesting from a thermal point of view. However, the complexity of the parallel configuration (management of flow rate distribution and flow rate non-uniformity) indicates that the use of a series configuration is more interesting from a global point of view, even if the series configuration produces less power dissipation. In particular because the power difference is not significant beyond the flow rate value H.
The flow rate value H, which turns from the series configuration to the parallel configuration, proves to be very high. As part of cooling the
Thus, in case there are multiple heat exchanging surfaces, it is preferred to use as much series structures between the surfaces as possible in order to keep the structure simple and efficient. However, the series connection of all the surfaces used will generate an excessively high pressure drop in the exchanger. Currently, pressure limitations in the ducts of the nacelle force the use of at most two surfaces in series.
If all surfaces are connected in parallel, the power dissipation is too low. In practice, each surface will be supplied at a low flow rate, which will reduce the convective exchange coefficient of the oil. In addition, non-uniformity in flow rate between the inner and outer surfaces will severely affect the structure.
In order to limit the flow rate non-uniformity and to make the heat exchange between the different ducts uniform, it is more interesting to use a structure consisting of a plurality of portions of two surfaces in series (the outer surface immediately follows the inner surface), which are to be supplied in parallel, as shown in fig. 8.
This structure allows an optimal supply of surfaces and has been retained within the use frame of the cooling nacelle. In fact, a series configuration of all surfaces would produce an excessive pressure drop for the same surface used, and is therefore not feasible. The parallel configuration will not dissipate sufficient thermal power. This is why the chosen configuration optimizes the thermal power/pressure drop pair by adopting a mixed series and parallel configuration.
Thus, the network of
In the example of embodiment shown in fig. 9, the
The turbine is connected to the
The oil outlets of the network of pipes of the inner wall are connected to the oil inlets of the network of pipes of the outer wall by a
The mixing structure allows to minimize the number of pipes in a first step by circulation of the oil at the level of the inner wall (from 12h to 6h) and then at the level of the outer wall (from 6h back to 12 h).
Of course, the connection of the pipes of the first and second liquid cooling circuits to the circulation means of the oil from the turbine does not necessarily take place at the 12 o' clock position. Depending on the orientation of the
The
The network of
Fig. 10 shows a further embodiment of the invention, in which a single liquid cooling circuit formed by a network of
Fig. 11 and 12 show another embodiment of the present invention applied to the downstream end of the
The
The oil is circulated to the network of
The width of each conduit is for example between one and one hundred millimetres. The term "width" is understood to mean the width according to the longitudinal section of the duct in question.
For efficiency reasons, the
According to a preferred example of embodiment,
Fig. 12 shows a network of
As shown in the drawings, the
Each
This design optimizes the temperature of the
The
The hybrid structure employed in the above examples according to embodiments of the invention, in which the heat exchangers, each consisting of a liquid pipe positioned in parallel on the outer or inner wall of the nacelle, are arranged in series in such a direction that the liquid circulates first through the exchanger or exchangers of the inner wall and then through the exchanger or exchangers of the outer wall, makes it feasible and advantageous to use the inner and outer surfaces of the nacelle in combination as heat exchange surfaces. The conventional parallel structure cannot provide sufficient heat exchange. The same applies to a series arrangement which cannot ensure the manufacturability of the exchange wall because of pressure limitations due to excessive pressure drops.
The proposed mixing structure is optimal because it ensures both a satisfactory heat dissipation of the liquid and a reduction in the number of surfaces used, while being robust to the phenomenon of flow rate non-uniformity. In the particular example of an embodiment in which the network of
a weight reduction of 12kg of airborne oil,
reduced number of surfaces used: of the twenty units of exchange surface required for the parallel structure, there are six units of exchange surface (per pipe), i.e. the mass of the structure is reduced by 70% by reducing the number of pipes in particular,
fewer parallel pipes, i.e. simpler flow rate distribution between pipes and a reduced number of interfaces and pipes, an
The exchanges in the ducts at all the flying points are coordinated, i.e. the flow rate non-uniformity is reduced, so that each surface piece operates under similar conditions.
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