The invention concerns a supply air unit.
Supply air units or air-conditioning beams usually comprise a supply air chamber, a mixing chamber and a heat exchanger. The flow of fresh air is brought from the supply air chamber into the mixing chamber, wherein the flow of fresh air is mixed with the circulated airflow, where-upon the combined airflow is conducted to the room space. The circulated airflow is conducted into the mixing chamber through a heat exchanger, in which the circulated airflow can be heated or cooled. Using the same supply air unit the room air can be cooled in the summer time and heated in the winter time. In the summer time, the circulated airflow of the room is cooled, and in the winter time it is heated in the supply air unit's heat exchanger. The flow of fresh air induces the circulated airflow to flow from the room through the heat exchanger into the mixing chamber.
The FI patent application 20060035 has presented a supply air unit and a method for controlling the airflow rate. The supply air unit comprises a supply air chamber, a heat exchanger, with which the circulated airflow conducted from the room space to be air-conditioned can be either cooled or heated, and a mixing chamber. A flow of fresh air is conducted from the supply air chamber through nozzles or a nozzle gap into the mixing chamber, in which the supply airflow induces the circulated airflow from the room to flow through the heat exchanger into the mixing chamber. In the mixing chamber, the flow of fresh air and the circulated airflow are combined, whereupon the combined airflow is conducted from the mixing chamber's outlet opening into the room space to be air-conditioned. The supply air unit also comprises an additional air opening, which is arranged on the flow path of the fresh airflow, separately from the nozzles or the nozzle gap, and a control device in connection with it for controlling the total rate of fresh airflow to be supplied from the supply air unit into the air-conditioned room space. The additional air opening can be arranged in such a way that the fresh airflow will discharge from it either directly into the air-conditioned room space or into the mixing chamber.
The FI Patents 117682 B, 118236 B present supply air units comprising a supply air chamber, a heat exchanger, with which the circulated airflow conducted from the air-conditioned room space can be either cooled or heated, and a mixing chamber. The fresh airflow is conducted from the supply air chamber through nozzles or a nozzle gap into the mixing chamber, in which the supply airflow induces the circulated airflow from the room to flow through the heat exchanger into the mixing chamber. In the mixing chamber, the fresh airflow and the circulated airflow are combined, whereupon the combined airflow is conducted from the mixing chamber's outlet opening into the air-conditioned room space. These publications present various systems for controlling the induction ratio and for controlling either the rate of fresh airflow to be supplied into the mixing chamber or the rate of circulated airflow to be conducted from the air-conditioned room space into the mixing chamber.
The FI Patent 113798 B for its part presents a supply air unit, which comprises a supply air chamber and a mixing chamber. A fresh airflow is conducted from the supply air chamber through nozzles or a nozzle gap into the mixing chamber, in which the supply airflow induces the circulated airflow from the room to flow into the mixing chamber. In the mixing chamber, the fresh airflow and the circulated airflow are combined, whereupon the combined airflow is conducted from the mixing chamber's outlet opening into the air-conditioned room space. The publications present various systems for controlling the induction ratio and for controlling either the rate of fresh airflow to be supplied into the mixing chamber or the rate of circulated airflow to be conducted from the air-conditioned room space into the mixing chamber.
In the supply air unit according to the invention there is at least one airflow controller, through which an additional airflow is conducted from the supply air chamber into at least one suction chamber, from which the bypass flow of fresh air is guided into at least one mixing chamber.
The airflow controller is used to control the additional airflow into the suction chamber, whereby the rate of air to be supplied from the supply air unit into the air-conditioned room space can be controlled within definite limits without having to exchange the nozzles of the supply air unit. A certain minimum airflow rate must be conducted all the time through the nozzles, because this minimum rate is necessary in order to induce the circulated airflow and in this way to achieve a sufficient cooling and heating effect. Using the airflow controller it is possible to increase the supply air unit's total airflow rate 1-6 times compared with the minimum airflow rate.
When the additional airflow is conducted into the suction chamber, the rate of circulated airflow to be conducted from the air-conditioned room space into the suction chamber is reduced, but the airflow rate to be conducted from the suction chamber into the mixing chamber remains almost constant. Should the temperature of the additional airflow differ from the temperature of the circulated airflow of the air-conditioned room space, the additional airflow can be used for controlling the cooling or heating effect. On the other hand, the total fresh airflow rate to be supplied from the supply air unit into the air-conditioned room space (the fresh airflow supplied from the supply air unit's nozzles into the mixing chamber +the additional airflow supplied from the supply air chamber into the suction chamber and from this into the mixing chamber) can be increased or reduced without affecting the rate of combined airflow conducted from the mixing chamber into the room space and in this way the flow pattern. Besides, in this manner the additional airflow is distributed evenly through the suction chamber.
The solution according to the invention can very well be used, for example, in a situation where a constant pressure is maintained on the supply air side by using a constant pressure controller.
An advantageous embodiment of the invention in connection with the airflow controller uses an air-permeable fabric, through which the bypass flow of fresh air is conducted into the suction chamber. In this manner the airflow velocity is reduced to a considerably lower level than the velocity of the airflow discharging from the nozzles. The lower velocity of the airflow for its part results in a lower noise level. Due to the lower velocity of the airflow, a higher pressure may be used in the supply air chamber. Owing to the low flow velocity of the additional air, the supply air unit's air distribution characteristics are determined based on the nozzle airflow and a possible induction controller located in the outlet opening of the mixing chamber.
In another advantageous embodiment of the invention, the supply air unit also comprises at least one heat exchanger. In such a solution the additional air to be supplied through the suction chamber and the heat exchanger into the mixing chamber can be after-heated or after-cooled in the heat exchanger. This may be required, for example, in a situation where the supply air unit is located in a negotiation room, where a large supply airflow may cause over- or under-cooling of the negotiation premises. By after-heating or after-cooling the additional airflow conducted through the suction chamber and the heat exchanger into the mixing chamber a suitable temperature can be controlled for the airflow combined in the mixing chamber.
In the following, the invention will be described by referring to some advantageous embodiments of the invention shown in the figures of the appended drawings, but there is no intention to restrict the invention to these alone.
a show a bottom view and a cross-sectional view, respectively, of an airflow controller solution according to the invention.
a show a bottom view and a cross-sectional view, respectively, of another airflow controller solution according to the invention.
a show a bottom view and a cross-sectional view, respectively, of a third airflow controller solution according to the invention.
The supply air unit 100 comprises a supply air chamber 10, which comprises a horizontal roof panel 11, below it and located at a distance from it a parallel ceiling panel 12, a first vertical outer side wall 13a, a second vertical outer side wall 13b, a first vertical inner side wall 14a and a second vertical inner side wall 14b. The top edge of the first vertical outer side wall 13a joins the left side edge of the roof panel 11, and the top edge of the second vertical outer side wall 13b joins the right side edge of the roof panel 11. The top edge of the first vertical inner side wall 14a joins the left side edge of the ceiling panel 12, and the top edge of the second vertical inner side wall 14b joins the right side edge of ceiling panel 12. The bottom edge of the first vertical outer side wall 13a is joined to the bottom edge of the first vertical inner side wall 14a by a first connecting wall 15a, and the bottom edge of the second vertical outer side wall 13b is joined to the bottom edge of the second vertical inner side wall 14b by a second connecting wall 15b. The supply air chamber 10 is thus formed by two separate lower chambers 10b1, 10b2, which are in connection with each other by way of one one-piece upper chamber 10a.
The fresh airflow L1 is brought into supply air chamber 10 through a horizontal X-X fitting 16 connected to the first vertical outer side wall 13a of supply air chamber 10. The connection 16 for supply air may be located in the roof panel 11, and not in the supply air chamber's 10 outer side wall 13a.
The supply air unit 100 also comprises two vertical heat exchangers 30a, 30b, which are located at a distance from each other and have a rectangular cross-sectional shape and which at their top end are supported against the supply air chamber's 10 ceiling wall 12. A suction chamber 40 with a rectangular cross-sectional shape is formed in the space between the heat exchangers 30a, 30b. The lower part of suction chamber 40 contains a bottom plate 50, which is supported against the bottom end of the heat exchangers 30a, 30b. The middle part 52 of bottom plate 50 has openings, through which the circulated airflow L2 can be conducted from the air-conditioned room space into the suction chamber 40. A first mixing chamber 20a with a rectangular cross-sectional shape is formed in the space between the first heat exchanger 30a and the supply air chamber's 10 first vertical inner side wall 14a. A second mixing chamber 20b with a rectangular cross-sectional shape is formed in the space between the second heat exchanger 30b and the supply air chamber's 10 second vertical inner side wall 14b. In the ceiling of the first mixing chamber 20a, that is, in the ceiling panel 11 of supply air chamber 10, there is a first nozzle row 60a, through which the fresh airflow L1 is conducted from supply air chamber 10 into the first mixing chamber 20a. In the ceiling of the second mixing chamber 20b, that is, in the ceiling panel 11 of supply air chamber 10, there is a second nozzle row 60b, through which the fresh airflow L1 is conducted from supply air chamber 10 into the second mixing chamber 20a.
In the lower part of the first mixing chamber 20a a first outlet opening 25a is formed, which is limited by the first connecting wall 15a and by the bottom plate's 50 left side edge 51a. In the lower part of the second mixing chamber 20b a second outlet opening 25b is formed, which is limited by the second connecting wall 15b and by the bottom plate's 50 right side edge 51b. Both outlet openings 25a, 25b are shaped in such a way that the airflow is guided from mixing chamber 20a, 20b in the air-conditioned room space to the side, essentially in the direction of the room's ceiling surface.
In the suction chamber's 40 ceiling, that is, in supply air chamber's 10 ceiling panel 11, the supply air unit 100 also comprises at least one airflow controller 70, through which an additional airflow L3 can be conducted from supply air chamber 10 into suction chamber 40.
In each mixing chamber 20a, 20b the fresh airflow L1 builds up a vacuum, which will suck or induce the circulated airflow L2 from the air-conditioned room space into suction chamber 40 and from this further through heat exchangers 30a, 30b into mixing chambers 20a, 20b. The additional airflow L3 is also sucked from suction chamber 40 through heat exchangers 30a, 30b into mixing chambers 20a, 20b. In mixing chambers 20a, 20b, the fresh airflow L1, the additional airflow L3 and the circulated airflow L2 form a combined airflow LA. The circulated airflow L2 and the additional airflow L3 can be cooled or heated in heat exchangers 30a, 30b. The combined airflow LA discharges from the outlet opening 25a, 25b located in the lower part of each mixing chamber 20a, 20b into the air-conditioned room space to the side, essentially in the direction of the room's ceiling surface.
The supply air unit 100 is symmetrical in relation to the vertical central axis Y-Y.
The supply air unit shown in
In connection with the bottom plate's 51 first edge part 51a a first damper 200a is mounted, with which the induction ratio of the first mixing chamber 20a can be controlled. In connection with the bottom plate's 51 second edge part 51b a second damper 200b is mounted for controlling the induction ratio of the second mixing chamber 20b. The fresh airflows L1 discharging from nozzles 60a, 60b are directed into mixing chambers 20a, 20b and they induce the circulated airflow L2 to flow through the openings in the bottom plate's 50 middle part 52 into suction chamber 40 and from this further into mixing chambers 20a, 20b. By raising and lowering the dampers 200a, 200b the rate of circulated airflow L2 conducted from suction chamber 40 into mixing chambers 20a, 20b can be controlled, whereby the induction ratio will change.
In connection with the vertical section 14a1 of the first outer side wall 14a a first damper 200a is mounted for controlling the induction ratio of the first mixing chamber 20a. In connection with the vertical section 14b1 of the second outer side wall 14b a second damper 200b is mounted for controlling the induction ratio of the second mixing chamber 20b. The fresh airflows L1 discharging from nozzles 60a, 60b are directed into mixing chambers 20a, 20b and they induce the circulated airflow L2 to flow into suction chambers 40a, 40b and from these further into mixing chambers 20a, 20b. By turning the dampers 200a, 200b it is possible to control the rate of circulated airflow L2 conducted from suction chambers 40a, 40b into mixing chambers 20a, 20b, whereby the induction ratio is changed.
a show an airflow controller solution according to the invention.
Inside the collar there is thus formed an opening, which opens into the opening 12a in the ceiling panel 12 and which is limited by the transverse part only. The disc valve also comprises a control disc 73, which through a threaded pin 74 is supported in the threaded hole 72 located in the middle of bottom part 71. The rate of air discharging from the airflow controller can be controlled by controlling the distance of control disc 73 from bottom part 71 by turning the control disc 73 in the way indicated by arrow S1. To the outer periphery of control disc 73 an air-permeable fabric 75 is also mounted, which extends to the stretch between disc 73 and ceiling panel 12. The air-permeable fabric 75 may consist, for example, of gauze. The top end of the air-permeable fabric 75 must be supported against the ceiling panel 12 or the bottom part 71 in such a way that the air-permeable fabric 75 can rotate along with the control disc 73 when the disc valve is opened or closed by turning the control disc 73. An additional airflow L3 is conducted from supply air chamber 10 through the opening 12a of the supply air chamber's 10 ceiling panel 12 and through the opening in the disc valve's bottom part 71 and then further through the air-permeable fabric 75 into the lower suction chamber 40 of airflow controller 70.
a show another airflow controller solution according to the invention.
a show a third airflow controller solution according to the invention.
In the embodiment shown in
In the embodiment shown in
In the embodiment shown in
In the embodiments shown in the figures, the fresh airflow L1 is supplied from the supply air chamber 10 through nozzles 60, 60a, 60b into mixing chambers 20, 20a, 20b. The nozzles 60, 60a, 60b can be replaced by a nozzle gap, through which the fresh airflow L1 is conducted from supply air chamber 10 into the mixing chambers 20, 20a, 20b.
The above presentation presented only a few advantageous embodiments of the invention, and it is obvious to a person skilled in the art that numerous modifications can be made to them within the scope defined in the appended claims.
This application is a divisional application of copending application Ser. No. 12/949,244 filed Nov. 18, 2010, and claims priority to Finnish patent application 20096195 filed Nov. 18, 2009.
Number | Date | Country | |
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Parent | 12949244 | Nov 2010 | US |
Child | 14318261 | US |