The present invention relates to an air conditioning piping structure for an aircraft, and an air conditioning system having the air conditioning piping structure for an aircraft.
In general, an air conditioning system with which an aircraft is equipped includes: air conditioning apparatuses each of which control a flow rate and a temperature using bleed air from an engine and outside air, thus obtaining temperature adjusted air; a mixing chamber which mixes the temperature adjusted air and recirculated air; a supply system which supplies the conditioned air obtained by the mixing chamber to pressurized compartments, such as the cabin and the cockpit; and a recirculation system which causes air discharged from the pressurized compartments to recirculate.
The mixing chamber receives and mixes temperature adjusted air from the air conditioning apparatus, and recirculated air from the recirculation system, the recirculated air usually having a higher temperature than the temperature adjusted air.
The air conditioning apparatus is provided in each of the starboard side and the port side of an aircraft. The temperature adjusted air flows into the mixing chamber trough a right pipe from a starboard air conditioning apparatus, and the temperature adjusted air flows into the same mixing chamber through a left pipe also from a port air conditioning apparatus. Recirculated air also flows into the same mixing chamber through each of the right pipe and the left pipe.
The temperature adjusted air and the recirculated air which flow into the mixing chamber respectively from each of the starboard side and the port side are mixed in the mixing chamber so that pressurized compartments can obtain conditioned air having an appropriate temperature. The conditioned air which flows out from a plurality of respective outlets of the mixing chamber is fed to the cabin and the like.
A mixer for an air conditioning apparatus disclosed in JP2007-505786W has a double structure which includes a first pipe, and a second pipe which has a larger diameter than the first pipe, and which surrounds a portion of the first pipe. The inside of the first pipe and the inside of the second pipe communicate with each other through a plurality of holes formed in the wall of the first pipe. Accordingly, temperature adjusted air which flows into the first pipe and recirculated air which flows into the second pipe are mixed in the mixer.
In order to promote mixing of temperature adjusted air and recirculated air, it is preferable to cause temperature adjusted air and recirculated air to be merged upstream of a chamber on each of the starboard side and the port side. In such a case, merged air on the starboard side flows into the starboard inlet of the chamber, and merged air on the port side flows into the port inlet of the chamber. On each of the starboard side and the port side, temperature adjusted air and recirculated air are mixed in advance during flowing to the inlet of the chamber after the temperature adjusted air and the recirculated air are merged. Accordingly, it is possible to obtain an advantageous effect of promoting mixing in the chamber.
From the viewpoint of making the temperatures of air flowing out from the chamber uniform among the plurality of outlets by sufficiently mixing temperature adjusted air and recirculated air, it is preferable that a zone where temperature adjusted air and recirculated air flow into the inlet of the chamber after the temperature adjusted air and the recirculated air are merged have a long length. However, there may be a case where it is difficult for the zone to have a long length due to restrictions on routing of the pipes.
It is an object of the present invention to provide an air conditioning piping structure for an aircraft which can promote mixing of temperature adjusted air and recirculated air flowing into a mixing chamber forming an air conditioning system, and to provide an air conditioning system having the air conditioning piping structure for an aircraft.
A first air conditioning piping structure of the present invention causes temperature adjusted air obtained by an air conditioning apparatus of an aircraft and recirculated air discharged from a region to which the temperature adjusted air is supplied to flow into a mixing chamber which mixes the temperature adjusted air and the recirculated air.
Such an air conditioning piping structure includes a first pipe through which the temperature adjusted air flows; a second pipe through which the recirculated air flows, and which is connected to the first pipe; and a flow passage restricting part configured to apply a resistance to at least one of the temperature adjusted air and the recirculated air at a position in a vicinity of a merging position where the temperature adjusted air and the recirculated air are merged.
A second air conditioning piping structure of the present invention causes temperature adjusted air obtained by an air conditioning apparatus of an aircraft and recirculated air discharged from a region to which the temperature adjusted air is supplied to flow into a mixing chamber which mixes the temperature adjusted air and the recirculated air.
Such an air conditioning piping structure includes: a first pipe through which the temperature adjusted air flows; a second pipe through which the recirculated air flows, and which is connected to the first pipe; and a flow passage restricting part configured to apply a resistance to a merged flow of the temperature adjusted air and the recirculated air.
In the second air conditioning piping structure of the present invention, it is preferable that a cross-sectional area of a flow passage at a position downstream of a merging position where the temperature adjusted air and the recirculated air are merged and in the vicinity of the merging position be reduced by the flow passage restricting part, and the flow passage restricting part be positioned at least on a second pipe side in cross section of the flow passage.
In each of the first and second air conditioning piping structures of the present invention, it is preferable that the flow passage restricting part be formed into an annular shape or a cylindrical shape along a circumferential direction of a cross section of a flow passage at a position in the vicinity of the merging position where the temperature adjusted air and the recirculated air are merged or downstream of the merging position.
It is preferable that each of the first and second air conditioning piping structures of the present invention include: a right first pipe forming the first pipe through which the temperature adjusted air obtained by an air conditioning apparatus which corresponds to a starboard side flows; a right second pipe forming the second pipe through which the recirculated air flows toward a position where the recirculated air is merged with the temperature adjusted air flowing through the right first pipe; a left first pipe forming the first pipe through which the temperature adjusted air obtained by an air conditioning apparatus which corresponds to a port side flows; and a left second pipe forming the second pipe through which the recirculated air flows toward a position where the recirculated air is merged with the temperature adjusted air flowing through the left first pipe, wherein the mixing chamber includes: a right inlet which causes the temperature adjusted air and the recirculated air which respectively flow through the right first pipe and the right second pipe and are merged to flow into the mixing chamber; and a left inlet which causes the temperature adjusted air and the recirculated air which respectively flow through the left first pipe and the left second pipe and are merged to flow into the mixing chamber from a side opposite to the right inlet, and the flow passage restricting part is provided with respect to at least one of merging of the temperature adjusted air and the recirculated air on a right side and merging of the temperature adjusted air and the recirculated air on a left side.
A third air conditioning piping structure of the present invention causes temperature adjusted air obtained by an air conditioning apparatus of an aircraft and recirculated air discharged from a region to which the temperature adjusted air is supplied to flow into a mixing chamber which mixes the temperature adjusted air and the recirculated air.
Such an air conditioning piping structure includes: a first pipe through which the temperature adjusted air flows; a second pipe through which the recirculated air flows, and which is connected to the first pipe; and a guide part configured to guide the recirculated air toward an upstream side of the temperature adjusted air flowing through the first pipe.
In the third air conditioning piping structure of the present invention, it is preferable that, at a position where the temperature adjusted air and the recirculated air are merged, an angle formed by a flow of the temperature adjusted air and a flow of the recirculated air be an acute angle or a right angle.
In the third air conditioning piping structure of the present invention, it is preferable that the second pipe be formed into a shape which includes the guide part.
It is preferable that the third air conditioning piping structure of the present invention include: a right first pipe forming the first pipe through which the temperature adjusted air obtained by an air conditioning apparatus which corresponds to a starboard side flows; a right second pipe forming the second pipe through which the recirculated air flows toward a position where the recirculated air is merged with the temperature adjusted air flowing through the right first pipe; a left first pipe forming the first pipe through which the temperature adjusted air obtained by an air conditioning apparatus which corresponds to a port side flows; and a left second pipe forming the second pipe through which the recirculated air flows toward a position where the recirculated air is merged with the temperature adjusted air flowing through the left first pipe, wherein the mixing chamber includes: a right inlet which causes the temperature adjusted air and the recirculated air which respectively flow through the right first pipe and the right second pipe and are merged to flow into the mixing chamber; and a left inlet which causes the temperature adjusted air and the recirculated air which respectively flow through the left first pipe and the left second pipe and are merged to flow into the mixing chamber from a side opposite to the right inlet, and the guide part is provided with respect to at least one of merging of the temperature adjusted air and the recirculated air on a right side and merging of the temperature adjusted air and the recirculated air on a left side.
It is preferable that each of the first to third air conditioning piping structures of the present invention include a premixing zone where the temperature adjusted air and the recirculated air are merged, and flow into the mixing chamber.
It is also preferable that the premixing zone extend along an axis of the first pipe.
It is preferable that each of the first to third air conditioning piping structures of the present invention include the mixing chamber.
It is preferable that each of the first to third air conditioning piping structures of the present invention include: a right first pipe forming the first pipe through which the temperature adjusted air obtained by an air conditioning apparatus which corresponds to a starboard side flows; a right second pipe forming the second pipe through which the recirculated air flows toward a position where the recirculated air is merged with the temperature adjusted air flowing through the right first pipe; a left first pipe forming the first pipe through which the temperature adjusted air obtained by an air conditioning apparatus which corresponds to a port side flows; and a left second pipe forming the second pipe through which the recirculated air flows toward a position where the recirculated air is merged with the temperature adjusted air flowing through the left first pipe, wherein the mixing chamber includes: a right inlet which causes the temperature adjusted air and the recirculated air which respectively flow through the right first pipe and the right second pipe and are merged to flow into the mixing chamber; a left inlet which causes the temperature adjusted air and the recirculated air which respectively flow through the left first pipe and the left second pipe and are merged to flow into the mixing chamber from a side opposite to the right inlet; a right premixing zone which extends to the right inlet from a position where the temperature adjusted air and the recirculated air which respectively flow through the right first pipe and the right second pipe are merged; and a left premixing zone which extends to the left inlet from a position where the temperature adjusted air and the recirculated air which respectively flow through the left first pipe and the left second pipe are merged; and a length of the right premixing zone and a length of the left premixing zone differ from each other.
In the above-mentioned configuration, it is preferable that a constitutional element for promoting mixing which is selected from the flow passage restricting part and the guide part be provided with respect to at least one of merging of the temperature adjusted air and the recirculated air on a right side and merging of the temperature adjusted air and the recirculated air on a left side.
An air conditioning system of an aircraft of the present invention includes: the above-mentioned air conditioning piping structure; the air conditioning apparatus configured to obtain the temperature adjusted air using bleed air and outside air; a supply system configured to supply conditioned air which passes through the mixing chamber to the air-conditioned compartment; and a recirculation system where the recirculated air discharged from the air-conditioned compartment flows.
According to the present invention, it is possible to promote mixing of temperature adjusted air and recirculated air at a position upstream of the mixing chamber by the flow passage restricting part which is positioned in the vicinity of the merging position or downstream of the merging position, or by the guide part which guides the recirculated air toward the upstream side of the temperature adjusted air.
Mixing of temperature adjusted air and recirculated air are promoted at a position upstream of the mixing chamber so that the temperature adjusted air and the recirculated air are more sufficiently mixed in the mixing chamber. Accordingly, it is possible to make the temperature of conditioned air flowing out from respective outlets of the mixing chamber uniform.
Hereinafter, an air conditioning piping structure for an aircraft according to embodiments of the present invention will be described with reference to attached drawings.
First, the schematic configuration of an entire air conditioning system 1 with which an aircraft is equipped will be described with reference to
The air conditioning system 1 (
The air conditioning system 1 includes air conditioning apparatuses 2 which obtain temperature adjusted air from bleed air and outside air, a mixing chamber 3 (mixing part), a supply system 4, and recirculation systems 5.
The air conditioning apparatus 2 is referred to as an Environmental control system (ECS).
In the air conditioning system 1, in order to lower fuel consumption of the aircraft, recirculated air, which is exhaust air from the pressurized compartment 40, is mixed into fresh temperature adjusted air obtained by the air conditioning apparatuses 2, and the mixture is supplied to the pressurized compartment 40.
The air conditioning apparatus 2 cools bleed air using outside air, thus obtaining temperature adjusted air. This temperature adjusted air is mixed with recirculated air by the mixing chamber 3 so that the pressurized compartment 40 can obtain conditioned air having an appropriate temperature.
The air conditioning apparatus 2 includes a compressor, a turbine, a heat exchanger, a flow rate valve, a dehumidifier and the like, for example, and controls the flow rate, the temperature and the like of temperature adjusted air. For example, the air conditioning apparatus 2 performs feedback control of the temperature in the pressurized compartment 40, thus controlling the flow rate and the temperature of temperature adjusted air.
Assume that “temperature adjusted air” refers to air which is controlled by the air conditioning apparatus 2 to a predetermined temperature using bleed air and outside air.
The air conditioning apparatus 2 (2R) which corresponds to a starboard side obtains temperature adjusted air using bleed air from the starboard engine and outside air. The air conditioning apparatus 2 (2L) which corresponds to a port side obtains temperature adjusted air using bleed air from the port engine and outside air. Both of the air conditioning apparatuses 2R, 2L use bleed air from the Auxiliary Power Unit while parked in place of bleed air from the engine.
Temperature adjusted air obtained by the starboard air conditioning apparatus 2R, temperature adjusted air obtained by the port air conditioning apparatus 2L, recirculated air flowing through the starboard recirculation system 5 (5R), and recirculated air flowing through the port recirculation system 5 (5L) are mixed in the mixing chamber 3.
The temperature adjusted air obtained by the air conditioning apparatus 2 and the recirculated air, which is air already supplied to the pressurized compartment 40 and circulated through the compartment, flows into the mixing chamber 3 at a flow rate ratio of 1:1, for example, and are mixed in the mixing chamber 3. Usually, the temperature of recirculated air is higher than the temperature of temperature adjusted air. A temperature difference between the temperature adjusted air and the recirculated air is 40 to 60° C., for example.
The conditioned air which has an appropriate temperature and which passes through the mixing chamber 3 is supplied to the pressurized compartment 40 through the supply system 4.
In
In the embodiment shown in
The pressurized compartment 40 includes the cockpit 41 (cockpit), a cabin 42 (cabin), and a cargo-compartment 43 (cargo). The cabin 42 is divided into a front region 421, which corresponds to a front body, and a rear region 422, which corresponds to a rear body. The supply system 4 supplies conditioned air to each of the front region 421 and the rear region 422.
In the embodiment shown in
The supply system 4 typically supplies conditioned air to the respective regions 41, 421, 422, 43 from respective blow-out ports on the starboard side and the port side. The supplied conditioned air circulated in the region is discharged to an underfloor space from discharge ports disposed near floor of the respective regions 41, 421, 422, 43, for example. A part (approximately ½, for example) of air under floor is suctioned by recirculation blowers 51R, 51L to the respective recirculation systems 5R, 5L, and the remaining air is discharged to a non-pressurized compartment via a pressure regulating valve (outflow valve) not shown in the drawing. In the embodiment shown in
Next, an air conditioning piping structure 30 according to the embodiment of the present invention will be described with reference to
The configuration of the air conditioning piping structure 30 described hereinafter is common to the respective embodiments of the present invention except for constitutional elements for promoting mixing described later.
The air conditioning piping structure 30 includes a starboard inflow pipe 30R which corresponds to the air conditioning apparatus 2R and the recirculation system 5R, a port inflow pipe 30L which corresponds to the air conditioning apparatus 2L and the recirculation system 5L, and the mixing chamber 3 into which temperature adjusted air and recirculated air flow respectively through the inflow pipes 30R, 30L.
As shown in
Outflow pipes not shown in the drawing are respectively connected to the outlets 11 to 14. The outlets 11 to 14 individually correspond to the blow-out port on the starboard side in the cabin front region 421, the blow-out port on the port side in the cabin front region 421, the blow-out port on the starboard side in the cabin rear region 422, and the blow-out port on the port side in the cabin rear region 422.
Unlike this embodiment, five outlets including an outlet for supplying air to the cockpit may be provided in the mixing chamber 3.
The starboard inflow pipe 30R causes temperature adjusted air and recirculated air to flow into the chamber body 3A from the inlet 10R.
The port inflow pipe 30L causes temperature adjusted air and recirculated air to flow into the chamber body 3A from the inlet 10L, which is positioned on the side opposite to the inlet 10R.
As shown in
The outlets 11 to 14 distribute in the circumferential direction of the chamber body 3A on the other end side in the axial direction of the chamber body 3A.
The diameter and the length in the axial direction of the chamber body 3A are appropriately set such that the inlets 10R, 10L and the outlets 11 to 14 can be arranged without interference between the respective openings of the inlets 10R, 10L and the outlets 11 to 14.
Temperature adjusted air and recirculated air which flow into the chamber body 3A in the tangential direction of the chamber body 3A from each of the inlet 10R and the inlet 10L are mixed while forming a swirling flow in the chamber body 3A, and the mixture flows out to outflow pipes not shown in the drawing from the outlets 11 to 14.
The starboard inflow pipe 30R includes a first pipe 31R through which temperature adjusted air obtained by the air conditioning apparatus 2R flows, and a second pipe 32R through which recirculated air flows, and which is connected to the first pipe 31R at a position upstream of the mixing chamber 3. The second pipe 32R forms a portion of the recirculation system 5R.
Temperature adjusted air and recirculated air are merged at a portion where the first pipe 31R and the second pipe 32R are connected with each other (see
The first pipe 31R and the second pipe 32R are connected with each other at the position upstream of the mixing chamber 3 and hence, temperature adjusted air and recirculated air are merged upstream of the mixing chamber 3 and, thereafter, flow into the inlet 10R and flow into the mixing chamber 3.
In the same manner, the port inflow pipe 30L includes a first pipe 31L through which temperature adjusted air obtained by the air conditioning apparatus 2L flows, and a second pipe 32L through which recirculated air flows, and which is connected to the first pipe 31L at a position upstream of the mixing chamber 3. The second pipe 32L forms a portion of the recirculation system 5L.
The first pipe 31L and the second pipe 32L are connected with each other at the position upstream of the mixing chamber 3 and hence, temperature adjusted air and recirculated air are merged upstream of the mixing chamber 3 and, thereafter, flow into the inlet 10L and flow into the mixing chamber 3.
In each of the inflow pipes 30R, 30L, temperature adjusted air and recirculated air are mixed in advance during flowing to the mixing chamber 3 after the temperature adjusted air and the recirculated air are merged. Accordingly, compared with the case where temperature adjusted air and recirculated air separately flow into the mixing chamber 3 without being merged, temperature adjusted air and recirculated air are mixed more sufficiently in the mixing chamber 3 before the temperature adjusted air and recirculated air flow out from the outlets 11 to 14 of the mixing chamber 3. That is, temperature adjusted air and recirculated air are merged upstream of the mixing chamber 3 and hence, mixing of the temperature adjusted air and the recirculated air is promoted.
The temperature adjusted air flowing through the starboard first pipe 31R and the recirculated air flowing through the starboard second pipe 32R flow through a premixing zone 34R from a merging position (merging position 33R) to the inlet 10R of the mixing chamber 3. In the embodiment shown in
The temperature adjusted air flowing through the port first pipe 31L and the recirculated air flowing through the port second pipe 32L flow through a premixing zone 34L from a merging position (merging position 33L) to the inlet 10L of the mixing chamber 3. In the embodiment shown in
The port premixing zone 34L is longer than the starboard premixing zone 34R. Accordingly, mixing of the temperature adjusted air and the recirculated air advances during flowing through the premixing zone 34L from the merging position 33L to the inlet 10L.
An outlet 15 is provided in the side wall of the port premixing zone 34L, and a part of the flow of the mixture of the temperature adjusted air and the recirculated air flowing through the premixing zone 34L is extracted toward the cockpit 41 through the outlet 15.
Each of the pipes 31R, 32R of the inflow pipe 30R and the pipes 31L, 32L of the inflow pipe 30L is formed to have a predetermined shape and a predetermined length from a viewpoint of causing temperature adjusted air and recirculated air to be sufficiently mixed while ensuring a flow rate required for each of the temperature adjusted air and the recirculated air.
Another viewpoint may be to allow a structure including the mixing chamber 3, the inflow pipes 30R, 30L, and the outflow pipes not shown in the drawing connected to the respective outlets of the mixing chamber 3 to be accommodated in an installation space given in the aircraft, and to avoid interference with members disposed around the structure. Reducing the weight of an airframe by suppressing the volume of the structure is preferable also from the viewpoint of lowering fuel consumption. It is preferable to set the shape, length and the like of the respective inflow pipes 30R, 30L by also taking into such viewpoints.
In terms of efficiency of promoting mixing of temperature adjusted air and recirculated air at the time of merging, it is preferable to connect the second pipe 32R to the first pipe 31R at a right angle.
However, due to reasons such as narrow installation space, there may be a case where the second pipe 32R has no option but to be connected to the first pipe 31R in an inclined state as in the case of this embodiment (see
In addition, the first pipe 31R may be connected to the second pipe 32R.
As shown in
The first pipe 31R and the second pipe 32R of the starboard inflow pipe 30R extend rearward from the front side, which is the upstream side, and are integrated into one pipe at a position forward of the chamber body 3A (premixing zone 34R), and the premixing zone 34R is connected to the inlet 10R positioned on the front side of the chamber body 3A.
The first pipe 31L and the second pipe 32L of the port inflow pipe 30L extend rearward from the front side, which is the upstream side, and are integrated into one pipe on the lateral side of the chamber body 3A (premixing zone 34L). The premixing zone 34L is routed to an area behind the chamber body 3A, and is connected to the inlet 10L, which is positioned on the rear side of the chamber body 3A.
The description will be made hereinafter with respect to constitutional elements for further promoting mixing of temperature adjusted air and recirculated air in the air conditioning piping structure 30 where the temperature adjusted air and the recirculated air are merged upstream of the mixing chamber 3 as described above.
An air conditioning piping structure 30 according to a first embodiment will be described with reference to
As shown in
In
As shown in
On the contrary to this embodiment, there may be a case where the port premixing zone 34L is shorter than the starboard premixing zone 34R due to the routing passage of the inflow pipes 30R, 30L. In such a case, it is preferable to provide the flow passage restricting part 35 at a position in the vicinity of the port merging position 33L.
As shown in
With the installation of the flow passage restricting part 35, the cross-sectional area of the flow passage in the premixing zone 34R is reduced by an amount corresponding to the area of the region of the flow passage restricting part 35 shown in gray in
The shape in cross section of each pipe, such as the first pipe 31R, the second pipe 32R, and the premixing zone 34R, is not limited to a circular shape, and may be an appropriate shape, such as an elliptical shape or a rectangular shape.
The flow passage restricting part 35 may be formed into an appropriate shape provided that the flow passage restricting part 35 can apply a resistance to at least one of temperature adjusted air and recirculated air at a position in the vicinity of the merging position 33R.
The flow passage restricting part 35 may have a plate shape as shown in
In the embodiment shown in
The flow passage restricting part 35 may be mounted on the pipe in the premixing zone 34R as in the case of this embodiment. Alternatively, the flow passage restricting part 35 may be integrally formed with the pipe in the premixing zone 34R.
As shown in
This flow passage restricting part 35 applies a flow resistance mainly to the flow of recirculated air of temperature adjusted air and recirculated air at a position downstream of the merging position 33R. With the installation of the flow passage restricting part 35, a resistance is applied. However, the necessary pressure and flow rate of each of the temperature adjusted air and the recirculated air are ensured to maintain the function of the air conditioning system 1, such as cooling/heating, pressurization, and ventilation.
Temperature adjusted air and recirculated air are gradually mixed while transferring and receiving heat based on a density difference which corresponds to a temperature difference during flowing through the premixing zone 34R. In addition to the above, a resistance is applied to the temperature adjusted air and the recirculated air by the flow passage restricting part 35 so that a flow motion is generated in the temperature adjusted air and the recirculated air whereby the temperature adjusted air and the recirculated air are mixed. The temperature adjusted air and the recirculated air to which the flow motion is applied by the flow passage restricting part 35 are mixed while being stirred by a flow motion and transferring and receiving heat.
Even when the premixing zone 34R where temperature adjusted air and recirculated air are mixed has a small length, an appropriate resistance is applied by the flow passage restricting part 35 to the flow of the temperature adjusted air and the recirculated air merged and hence, mixing of the temperature adjusted air and the recirculated air can be sufficiently promoted before the terminal end (inlet 10R) of the premixing zone 34R.
Meanwhile, with respect to the flow of the temperature adjusted air and the recirculated air merged at the merging position 33L in the port inflow pipe 30L (
Depending on the length of the premixing zone 34L, the temperature of temperature adjusted air flowing through the first pipe 31L, the temperature of recirculated air flowing through the second pipe 32L and the like, mixing can be promoted by providing the flow passage restricting part 35 also to the port inflow pipe 30L.
The flow merged in the inflow pipe 30R and the flow merged in the inflow pipe 30L respectively flow into the mixing chamber 3 from the inlet 10R and the inlet 10L. Then, the flows are more sufficiently mixed in the mixing chamber 3 while swirling before the flows flow out from the outlets 11 to 14.
According to this embodiment, not only from the starboard inflow pipe 30R but also from the port inflow pipe 30L, a flow of the temperature adjusted air and the recirculated air merged flows into the mixing chamber 3 in a state where the flows have small temperature deviation. Accordingly, before the flows reach the outlets 11 to 14 of the mixing chamber 3, the temperature adjusted air and the recirculated air can be sufficiently mixed until the temperature adjusted air and recirculated air assume a uniform temperature.
Even if there is a temperature difference in either one or both of the temperature adjusted air and the recirculated air between the starboard inflow pipe 30R and the port inflow pipe 30L, such a temperature difference is sufficiently smaller than a temperature difference between the temperature adjusted air and the recirculated air.
That is, there may be a case where there is a variation in temperature of temperature adjusted air or in temperature of recirculated air between the inflow pipe 30R and the inflow pipe 30L. Also in such a case, a deviation in temperature is set small using the action of the flow passage restricting part 35 in the inflow pipe 30R where the premixing zone 34R disposed on the downstream of the merging position has a small length, and the temperature adjusted air and the recirculated air which flow into the mixing chamber 3 from the inflow pipes 30R, 30L are sufficiently mixed in the mixing chamber 3. Accordingly, the temperature of conditioned air flowing out from the outlets 11 to 14 of the mixing chamber 3 can be made uniform.
In the comparison example (
In this comparison example, the presence of the region A1 having a high temperature and the presence of the region A2 having a low temperature are observed in the outlet 12. The presence of a region A1 having a high temperature and the presence of a region A2 having a low temperature are also observed in the outlet 13. As described above, the flow rate ratio of temperature adjusted air to recirculated air is 1:1, for example. The flow rate ratio may vary due to temperature control performed by the air conditioning apparatus 2, external factors or the like. However, the flow rate ratio does not significantly depart from this ratio provided that control is performed within a usual range. In the comparison example, temperature adjusted air and recirculated air having substantially the same flow rate ratio flow into the mixing chamber 3 while forming a laminar flow which extends parallel to the pipe axis without being sufficiently mixed. It is considered that such flowing leads to a temperature difference among the outlets 11 to 14.
On the other hand, in this embodiment (
For example, in the comparison example, a difference between the maximum temperature and the minimum temperature among the outlets 11 to 14 is approximately 5° C. However, in this embodiment, a difference between the maximum temperature and the minimum temperature among the outlets 11 to 14 is only approximately 2.7° C.
A temperature difference among the outlets 11 to 14 of the mixing chamber 3 is small. Accordingly, it is possible to make the temperature of the entire room uniform, the room including the starboard side and the port side of the front region 421 of the cabin 42, and the starboard side and the port side of the rear region 422 of the cabin 42, and conditioned air being distributed to the front region 421 and the rear region 422 from the same mixing chamber 3. That is, conditioned air having an appropriate temperature can be supplied to the entire cabin 42.
If there is no unevenness of the temperature in the entire cabin 42, control of the air conditioning apparatus 2, which is performed based on the representative temperature detected at one portion or some portions of the cabin 42, is stably performed with a small fluctuation in the temperature of conditioned air while the use amount of bleed air is suppressed.
Due to the above-mentioned reasons, conditioned air whose temperature is stable at an appropriate temperature is supplied to the entire cabin 42 and hence, comfort of passengers can be enhanced. Further, control is efficiently performed by suppressing the use amount of bleed air, thus contributing to lowering of fuel consumption.
It is also possible to adopt a flow passage restricting part 36 shown in
The flow passage restricting part 36 applies a resistance to both of temperature adjusted air and recirculated air after merging. Also with this flow passage restricting part 36, it is possible to generate a flow motion in a merged flow, thus promoting mixing.
An opening 36A of the flow passage restricting part 36 which acts as a flow passage is not limited to a shape concentric with the axis of the premixing zone 34R, and may have a shape which is eccentric with respect to the axis of the premixing zone 34R. For example, in order to apply a resistance mainly to the flow of recirculated air, a width W2 on the recirculated air side may be larger than a width W1 on the temperature adjusted air side as in the case of a flow passage restricting part 36B shown in
Besides, the flow passage restricting part may be formed into an appropriate shape provided that the flow passage restricting part can apply a resistance to the flow of the temperature adjusted air and the recirculated air merged. For example, the entire flow passage restricting part may be formed into a mesh shape as in the case of a flow passage restricting part 37 shown in
When the flow passage restricting part 35 is installed in the vicinity of the merging position 33R as in the case of this embodiment, there is no possibility that the merged flow of temperature adjusted air and recirculated air maintains a laminar flow. Immediately after the temperature adjusted air and the recirculated air are merged, the temperature adjusted air and the recirculated air generates a flow motion due to the flow passage restricting part 35, thus being mixed. Thereafter, mixing of the temperature adjusted air and the recirculated air further advances during flowing to the inlet 10R. Accordingly, there is a high mixing promoting effect.
However, the position where the flow passage restricting part 35 is disposed is not limited to a position in the vicinity of the merging position 33R. Even when the flow passage restricting part 35 is disposed at an appropriate position downstream of the merging position 33R, it is also possible to promote mixing of temperature adjusted air and recirculated air.
Depending on the length of the premixing zone 34R, it is possible to increase a mixing promoting effect by arranging the plurality of flow passage restricting parts 35 in the premixing zone 34R at intervals in the direction of the pipe axis.
Referring to
The maximum temperature difference ΔTmax corresponds to the maximum temperature difference, among the outlets 11 to 14, between average temperatures of conditioned air which respectively flows out from the outlets 11 to 14 of the mixing chamber 3. That is, the maximum temperature difference ΔTmax corresponds to a difference between the maximum value and the minimum value of the average temperature at the respective outlets. A smaller maximum temperature difference ΔTmax indicates that a temperature is made more uniform among the outlets 11 to 14. The maximum temperature difference ΔTmax can be obtained by an analysis where predetermined setting conditions are given to temperature control performed by the air conditioning apparatus 2.
A pressure loss ΔPt is shown as a reference of an index of a resistance when air flows. The pressure loss ΔPt corresponds to the amount of dropping of pressure loss of 1000 Pa, for example.
As shown in
As can be understood from
The relationship between the aperture ratio Ar of the flow passage at the flow passage restricting part 36 shown in
Examples of another flow passage restricting parts are shown each of which is disposed in the vicinity of the merging position 33R in the same manner as the flow passage restricting part 35 in the first embodiment.
A flow passage restricting part 38 shown in
When a resistance is applied to temperature adjusted air flowing through the first pipe 31R by the flow passage restricting part 38, a flow motion is generated also in recirculated air with which temperature adjusted air is merged in addition to in the temperature adjusted air. Accordingly, mixing of temperature adjusted air and recirculated air can be promoted.
An opening 38B which acts as a flow passage at a flow passage restricting part 38A shown in
A flow passage restricting part 39 shown in
Note that the flow passage restricting part 39 may be formed of a throttle having an annular shape in the same manner as the flow passage restricting part 38 shown in
A resistance is applied to recirculated air by the flow passage restricting part 39 so that recirculated air and temperature adjusted air are caused to generate a flow motion whereby mixing of recirculated air and temperature adjusted air can be promoted.
With the installation of the flow passage restricting part 39, the flow passage of the second pipe 32R (an opening 39A of the flow passage restricting part 39) is shifted toward the upstream side of temperature adjusted air with respect to the axis of the second pipe 32R and hence, the flow of recirculated air is deflected toward the upstream side of temperature adjusted air. Accordingly, a stirring effect brought about by a flow motion generated at the time of merging is increased so that mixing of temperature adjusted air and recirculated air can be more promoted.
Next, an air conditioning piping structure 30A of a second embodiment will be described with reference to
Hereinafter, the description will be made mainly with respect to matters which are different from the first embodiment. The configurations substantially equal to that in the first embodiment are given the same reference symbols.
The air conditioning piping structure 30A of the second embodiment shown in
The guide part 301 has an inclined surface 302 which is inclined, with respect to the axis of the second pipe 32R, in a direction along which recirculated air is guided toward the upstream side of temperature adjusted air. An end portion 302B of the inclined surface 302 on the downstream side of recirculated air is positioned more inward in the radial direction of the second pipe 32R than an end portion 302A of the inclined surface 302 on the upstream side of recirculated air. It is preferable that the inclined surface 302 is smoothly continued to the inner peripheral portion of the second pipe 32R.
With the guide part 301, the flow passage in the vicinity of the terminal end of the second pipe 32R has the cross-sectional area gradually reducing toward the terminal end while the flow passage is shifted toward the upstream side of temperature adjusted air.
It is preferable that the second pipe 32R be formed into a shape which includes the guide part 301. With such a configuration, it is possible to obtain a mixing promoting effect without adding a member to the pipe.
Alternatively, the second pipe 32R may be caused to have a shape substantially equal to the guide part 301 by mounting a guide part 303 to the second pipe 32R as shown in
The flow of recirculated air is indicated by an arrow F2 in
That is, by the action of the guide part 301, the flow F2 of recirculated air is deflected toward the upstream side of temperature adjusted air with respect to the axis of the second pipe 32R. With such a deflection, the angle θ formed by the flow F2 of recirculated air and the flow F1 of temperature adjusted air is small. A merging angle θ may be an obtuse angle exceeding 90°. However, it is preferable that the merging angle θ be a right angle or less (right angle or acute angle).
With a smaller merging angle θ formed by recirculated air and temperature adjusted air, it is possible to obtain a higher stirring effect brought about by the impingement of the flow F1 and the flow F2 at the time of merging. Accordingly, a laminar flow is not easily formed whereby mixing is promoted.
In addition to the above, compared with the case where a throttle having an annular shape is disposed in the vicinity of the terminal end of the second pipe 32R, the merging position 33R between temperature adjusted air and recirculated air is shifted to the upstream side of temperature adjusted air. As a result, a distance from the merging position 33R to the inlet 10R is increased. Also with such an increase, mixing of temperature adjusted air and recirculated air can be more promoted.
From a certain viewpoint, by the action of the guide part 301, it is possible to obtain a merging angle θ substantially equal to that in the case where the second pipe 32R is connected to the first pipe 31R at a right angle in a state where the radius of curvature of the second pipe 32R is reduced. That is, there may be a case where the second pipe 32R is not allowed to be connected to the first pipe 31R at a right angle due to interference with members disposed around the second pipe 32R or restrictions, such as an installation space. Even in such a case, by providing the guide part 301 to an outer peripheral side 321 of the second pipe 32R which has a large radius of curvature of a curve, the merging angle θ can approximate to a right angle and hence, it is possible to increase a mixing promoting effect.
Also with the second embodiment, it is possible to obtain a mixing promoting effect substantially equal to that in the first embodiment where the flow passage is restricted in the vicinity of the merging position 33R. Specifically, it is possible to realize the maximum temperature difference ΔTmax and the pressure loss ΔPt which correspond to the aperture ratio Ar of approximately 78% shown in
Also in the second embodiment, mixing of temperature adjusted air and recirculated air is sufficiently promoted at a position upstream of the mixing chamber 3 and hence, the temperature of conditioned air flowing out from the outlets 11 to 14 of the mixing chamber 3 can be made uniform.
In addition to the above, in the second embodiment, recirculated air flows smoothly along the guide part 301 so that peeling or the like does not easily occur. Accordingly, it is possible to sufficiently obtain a mixing promoting effect while an increase in pressure loss caused by a reduction in cross-sectional area of the flow passage is suppressed.
A guide part 304 shown in
Besides the above, the configuration described in the above-mentioned embodiment may be selectively used, or may be appropriately changed to another configuration without departing from the gist of the present invention.
It is not indispensable that the premixing zone 34R extends with a predetermined length from the merging position 33R to the inlet 10R of the mixing chamber 3. Even in the case where a distance from the merging position 33R to the inlet 10R is close to zero, a constitutional element for promoting mixing, such as the flow passage restricting part 35 in the first embodiment or the guide part 301 in the second embodiment, is disposed in the vicinity of the merging position 33R and hence, it is possible to obtain an effect of promoting mixing of temperature adjusted air and recirculated air.
Number | Date | Country | Kind |
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2019-029678 | Feb 2019 | JP | national |