Evaporator in a refrigerant circuit E

Patent metadata

Field	Value
Publication number	US-10760835-B2
Application number	US-201816121749-A
Country	US
Kind code	B2
Filing date	Sep 5, 2018
Priority date	Sep 5, 2018
Publication date	Sep 1, 2020
Grant date	Sep 1, 2020

Abstract

An evaporator in a refrigerant circuit, having a bottom-side inlet chamber which is connected in flow terms to an evaporator outlet side via evaporator tubes, a separator being integrated into the evaporator inlet chamber, in which separator a refrigerant which is expanded in an expansion member is divided as a two-phase liquid/vapour mixture into a vapour phase and into a liquid phase which is separate therefrom, the vapour phase being conducted via a bypass line to the evaporator outlet side, and the liquid phase being conducted counter to the direction of gravity into the evaporator tubes, wherein at least one evaporator tube being a flat tube with a plurality of micro-channels, through which the refrigerant is guided.

First claim

The invention claimed is:

1. An evaporator in a refrigerant circuit, comprising:
an inlet chamber which is fluidly connected to an evaporator outlet chamber via evaporator tubes, and
a separator integrated into the inlet chamber, the separator having an expansion member in which a refrigerant is expanded as a two-phase liquid/vapour mixture and then divided into a vapour phase and into a liquid phase which is separate therefrom,
wherein the vapour phase is conducted via a bypass line to the evaporator outlet chamber,
wherein the liquid phase is conducted counter to the direction of gravity into the evaporator tubes,
wherein at least one evaporator tube is a flat tube with a plurality of micro-channels, through which the refrigerant is guided, each of the plurality of micro-channels having at least one orifice opening,
wherein the micro-channels of the flat tube are divided into at least one vapour phase micro-channel and into at least one liquid phase micro-channel,
wherein the vapour phase micro-channel forms the bypass line, and exclusively the liquid phase flows into the liquid phase micro-channel,
wherein the liquid phase micro-channel is dipped with at least one of the at least one orifice openings into the liquid phase which is collected in the inlet chamber, and
wherein the vapour phase micro-channel is positioned with at least one of the at least one orifice openings above a liquid phase level by a height offset.

2. The evaporator according to claim 1 , wherein the inlet chamber is delimited by a chamber bottom, side walls which are raised from the chamber bottom in the evaporator height direction, and a chamber top wall,
wherein the evaporator tubes protrude through the chamber top wall into the inlet chamber in the evaporator height direction in such a way that the at least one orifice openings of the micro-channels are spaced apart from the chamber bottom by a spacing, and
wherein the liquid phase collects in the inlet chamber, the surface of which delimits the liquid phase level.

3. The evaporator according to claim 2 , wherein the orifice opening of the vapour phase micro-channel is spaced from the chamber bottom to a greater extent than the spacing of the orifice opening of the liquid phase micro-channel.

4. The evaporator according to claim 1 , wherein the orifice openings of the micro-channels are configured in a flat tube end side which is planar and faces the chamber bottom, and
wherein the flat tube end side lies in an oblique plane which defines an oblique angle with a horizontal plane so that different spacings between the orifice openings of the micro-channels and the chamber bottom are formed.

5. The evaporator according to claim 4 , wherein the spacings of the orifice openings of the micro-channels from the chamber bottom lie between a minimum spacing and a maximum spacing, and in that the minimum spacing is dimensioned in such a way that the liquid phase level of the liquid phase which is collected in the inlet chamber is at least greater than the minimum spacing.

6. The evaporator according to claim 1 , wherein the inlet chamber is elongated in an evaporator transverse direction,
wherein the evaporator has a plurality of evaporator tubes which are arranged behind one another and at a spacing in the evaporator transverse direction in an aligned manner in a parallel arrangement,
wherein the parallel arrangement results in the formation of intermediate spaces between each evaporator tube, through which air can flow and which are arranged outside the inlet chamber, and
wherein the plurality of evaporator tubes each have an identical separator geometry in the region of their respective orifice openings.

7. The evaporator according to claim 1 , wherein the separator has a distributor tube which extends in the inlet chamber in an evaporator transverse direction and which has a reduced cross section in comparison with the inlet chamber,
wherein the two-phase liquid/vapour mixture flows via the distributor tube into the inlet chamber, and
wherein the distributor tube has at least one discharge opening, each of which is directed at a deflector wall, so that during operation, a refrigerant jet exiting from the discharge opening comes into contact with the deflector wall, resulting in a phase separation.

8. The evaporator according to claim 7 , wherein the at least one discharge opening is configured on the outer circumference of the distributor tube and/or is directed upwards in the evaporator height direction, and
wherein the deflector wall is a chamber top wall.

9. The evaporator according to claim 8 , wherein the evaporator tubes protrude in each case with a tube projection from the chamber top wall into the inlet chamber,
wherein at least one phase separation space is provided which is delimited by mutually facing flat sides of the tube projections, by the chamber top wall and by at least one side wall, and
wherein the refrigerant jet which exits from the distributor tube discharge opening is sprayed into the at least one phase separation space.

10. The evaporator according to claim 9 , wherein the distributor tube discharge opening is offset from the orifice openings of the evaporator tubes in the evaporator transverse direction by a transverse offset, with the result that the distributor tube discharge opening is directed directly onto the chamber top wall and the exiting refrigerant jet is guided past the orifice openings of the micro-channels,
wherein the distributor tube protrudes beyond the liquid phase level at least with its discharge opening, and
wherein the distributor tube is positioned at least with its discharge opening in an inner corner region which is defined between the liquid phase level and an evaporator tube end side.

Assignees

• Audi Ag

Inventors

• Hammer Hans
• Hrnjak Predrag
• Musser Andrew
• Elbel Stefan
• Che Jing

Classifications

• F28F1/022

  with multiple channels · CPC title

• F28D2021/0085

  Evaporators · CPC title

• F25B39/028 Primary

  having distributing means · CPC title

• F25B2400/23

  Separators · CPC title

• F28F9/0273

  with multiple holes · CPC title