HEAT PUMP HEATER

Abstract

A heat pump heater for an air conditioning system of a motor vehicle may include a first tube row and a second tube row each including a plurality of flat tubes arranged spaced apart from one another. The first and second tube row may be arranged in parallel to form a tube block. At least some flat tubes of the first tube row may lead into an inlet pipe and at least some flat tubes of the second tube row may lead into an outlet pipe. A refrigerant may be flowable from the inlet pipe via the first tube row and to the outlet pipe via the second tube row. The inlet pipe and the outlet pipe may be fluidically connected to one another via at least one bypass duct such that a liquid phase of the refrigerant is flowable out of the inlet pipe into the outlet pipe.

Claims

1. A heat pump heater for an air conditioning system of a motor vehicle, comprising: a first tube row including a plurality of flat tubes arranged spaced apart from one another; a second tube row including a plurality of flat tubes arranged spaced apart from one another; the first tube row and the second tube row arranged in parallel to form a tube block; at a connecting point of the tube block, at least some of the plurality of flat tubes of the first tube row lead into an inlet pipe via an inlet base and at least some of the plurality of flat tubes of the second tube row lead into an outlet pipe via an outlet base; wherein a refrigerant is flowable from the inlet pipe via the plurality of flat tubes of the first tube row and to the outlet pipe via the plurality of flat tubes of the second tube row; and wherein the inlet pipe and the outlet pipe are fluidically connected to one another via at least one bypass duct such that a liquid phase of the refrigerant is flowable via the at least one bypass duct, bypassing the plurality of flat tubes of the first tube row and the plurality of flat tubes of the second tube row, out of the inlet pipe into the outlet pipe.

2. The heat pump heater according to claim 1, wherein the at least one bypass duct is arranged in an end region of the inlet pipe, the end region arranged opposite to an inlet opening of the inlet pipe relative to a flow direction through the inlet pipe.

3. The heat pump heater according to claim 1, wherein the at least one bypass duct is arranged in a lower region of the inlet pipe, and wherein the lower region of the inlet pipe is arranged opposite the inlet base and extends over half a width of the inlet pipe in a longitudinal direction of the plurality of flat tubes of the first tube row.

4. The heat pump heater according to claim 1, wherein the at least one bypass duct is defined by a bypass pipe which fluidically connects the inlet pipe and the outlet pipe.

5. The heat pump heater according to claim 1, wherein the inlet pipe and the outlet pipe are arranged parallel and next to one another and are formed in a connecting manifold.

6. The heat pump heater according to claim 5, wherein the at least one bypass duct is defined by a continuous bypass opening disposed in the connecting manifold, which fluidically connects the inlet pipe and the outlet pipe.

7. The heat pump heater according to claim 1, wherein the at least one bypass duct has one of a round cross section, a square cross section, an oval cross section, and a rectangular cross section.

8. The heat pump heater according to claim 1, wherein a cross-sectional area of the at least one bypass duct is 0.2 mm.sup.2 to 9.0 mm.sup.2.

9. The heat pump heater according to claim 1, wherein the at least one bypass duct has a round cross section with a diameter of 0.5 mm to 3.4 mm.

10. The heat pump heater according to claim 1, wherein at least one of: at a diversion point of the tube block, at least some of the plurality of flat tubes of the first tube row and at least some of the plurality of flat tubes of the second tube row lead into a common diversion manifold via a diversion base; and at least two further tube rows are arranged between the first tube row and the second tube row, the at least two further tube rows each including a plurality of flat tubes, and wherein at a plurality of diversion points of the tube block at least some of the plurality of flat tubes of tube rows arranged next to one another lead into a respective common diversion manifold via a respective diversion base.

11. The heat pump heater according to claim 10, wherein the tube block includes the diversion point, and wherein at least one of: the connecting point is arranged on a connecting side of the tube block and the diversion point is arranged on a diversion side of the tube block disposed opposite the connecting side such that the refrigerant is flowable through the plurality of flat tubes of the first tube row in a first flow direction and through the plurality of flat tubes of the second tube row in a second flow direction opposite the first flow direction; and the connecting point and the diversion point are arranged on a common connecting side of the tube block such that the refrigerant is flowable through some of the plurality of flat tubes of the first tube row and some of the plurality of flat tubes of the second tube row in a first flow direction and some of the plurality of flat tubes of the first tube row and some of the plurality of flat tubes of the second tube row in a second flow direction opposite the first flow direction.

12. A heat pump heater for an air conditioning system of a motor vehicle, comprising: a tube block including a first tube row and a second tube row arranged in a parallel manner, the first tube row and the second tube row each including a plurality of flat tubes arranged spaced apart from one another; an inlet pipe connected to at least some of the plurality of flat tubes of the first tube row via an inlet base such that refrigerant is flowable out from the inlet pipe via the plurality of flat tubes of the first tube row; an outlet pipe connected to at least some of the plurality of flat tubes of the second tube via an outlet base such that refrigerant is flowable into the outlet pipe via the plurality of flat tubes of the second tube row; at least one bypass duct fluidically connecting the inlet pipe and the outlet pipe such that a liquid phase of refrigerant bypasses the plurality of flat tubes of the first tube row and the plurality of flat tubes of the second tube row and is flowable out of the inlet pipe and into the outlet pipe; and a connecting manifold in which the inlet pipe, the outlet pipe, and the at least one bypass duct are disposed.

13. The heat pump heater according to claim 12, wherein the inlet pipe, the outlet pipe, and the at least one bypass duct are each defined by the connecting manifold.

14. The heat pump heater according to claim 12, wherein the at least one bypass duct includes a plurality of bypass ducts disposed spaced apart from one another.

15. The heat pump heater according to claim 12, wherein the connecting manifold includes at least one continuous bypass opening extending between and fluidically connecting the inlet pipe and the outlet pipe, and wherein the at least one continuous bypass opening defines the at least one bypass duct.

16. The heat pump heater according to claim 12, further comprising a common diversion manifold, wherein at least some of the plurality of flat tubes of the first tube row and at least some of the plurality of flat tubes of the second tube row are connected to the common diversion manifold at a diversion point of the tube block via a diversion base.

17. The heat pump heater according to claim 16, wherein the connecting point of the tube block and the diversion point of the tube block are disposed on opposed ends of the tube block such that refrigerant is flowable through the plurality of flat tubes of the first tube row in a first flow direction and through the plurality of flat tubes of the second tube row in a second flow direction opposite the first flow direction.

18. The heat pump heater according to claim 16, wherein the connecting point of the tube block and the diversion point of the tube block are disposed on a same end of the tube block such that refrigerant is flowable through some of the plurality of flat tubes of the first tube row and some of the plurality of flat tubes of the second tube row in a first flow direction and through some of the plurality of flat tubes of the first tube row and some of the plurality of flat tubes of the second tube row in a second flow direction opposite the first flow direction.

19. A heat pump heater for an air conditioning system of a motor vehicle, comprising: a tube block including a first tube row and a second tube row arranged in a parallel manner, the first tube row and the second tube row each including a plurality of flat tubes arranged spaced apart from one another; an inlet pipe connected to at least some of the plurality of flat tubes of the first tube row via an inlet base such that refrigerant is flowable out from the inlet pipe via the plurality of flat tubes of the first tube row; an outlet pipe connected to at least some of the plurality of flat tubes of the second tube via an outlet base such that refrigerant is flowable into the outlet pipe via the plurality of flat tubes of the second tube row; at least one bypass duct fluidically connecting the inlet pipe and the outlet pipe such that a liquid phase of refrigerant bypasses the plurality of flat tubes of the first tube row and the plurality of flat tubes of the second tube row and is flowable out of the inlet pipe and into the outlet pipe; wherein the inlet pipe includes an inlet opening via which refrigerant is flowable into the inlet pipe, the outlet pipe includes an outlet opening via which refrigerant is flowable out of the outlet pipe, and the at least one bypass duct extends between the inlet pipe and the outlet pipe in an end region disposed opposite the inlet opening and the outlet opening.

20. The heat pump heater according to claim 19, wherein: the at least one bypass duct is connected to a lower region of the inlet pipe disposed opposite the inlet base; and the at least one bypass duct is connected to the inlet pipe such that extends over half of a width of the inlet pipe extending in a longitudinal direction of the plurality of flat tubes of the first tube row and the plurality of flat tubes of the second tube row.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0022] It shows, in each case schematically

[0023] FIG. 1 shows a view of a heat pump heater according to the invention;

[0024] FIG. 2 shows a view of a connecting manifold with an inlet base and an outlet base in the heat pump heater according to the invention;

[0025] FIG. 3 shows a sectional view through the connecting manifold shown in FIG. 2;

[0026] FIG. 4 shows a view of the heat pump heater according to the invention with the distribution of the air temperature on an outlet area;

[0027] FIG. 5 shows a view of the conventional heat pump heater with the distribution of the air temperature on an outlet area.

DETAILED DESCRIPTION

[0028] FIG. 1 shows a view of a heat pump heater 1 according to the invention for an air conditioning system of a motor vehicle. The heat pump heater 1 comprises a first tube row 2a with multiple flat tubes 3a arranged spaced from one another and a second tube row 2b with multiple flat tubes 3b spaced from one another. Here, the first tube row 2a is arranged on the second tube row 2b so that the tube rows 2a and 2b form a two-row tube block 4 of the heat pump heater 1. At a diversion point 5 of the tube block 4, the flat tubes 3a and 3b of the tube rows 2a and 2b lead into a common diversion manifold 7 via a diversion base 6. At a connecting point 8 of the tube blocks 4, the flat tubes 3a of the first tube row 2a lead into an inlet pipe 10 via an inlet base 9 and the flat tubes 3b of the second tube row 2b into an outlet pipe 12 via an outlet base 11. The inlet pipe 10 and the outlet pipe 12 are formed in a connecting manifold 12 and arranged next to one another. The connecting point 8 in this exemplary embodiment is arranged on a connecting side 13 of the tube block 4 and the diversion point 5 is arranged on a diversion side 14 of the tube block 4 located opposite the connecting side 13. Accordingly, the diversion manifold 7 is fixed on the diversion side 14 and the connecting manifold 17 on the connecting side 13.

[0029] In the heat pump heater 1, the refrigerant flows into the inlet pipe 10 via an inlet opening 10a and further through the flat tubes 3a of the first row 2a in a first flow direction 15a towards the diversion manifold 7. In the diversion manifold 7, the refrigerant is apportioned to the flat tubes 3b and flows through the same in a second flow direction 15b towards the outlet pipe 12. Following this, the refrigerant flows via an outlet opening 12b out of the outlet pipe 12. The air enters the heat pump heater 1 at an inlet surfacenot visible hereand exits on an outlet area 16 located opposite. Here, the air first flows about the flat tubes 3b of the second tube row 2b with a cooler refrigerant and thereafter the flat tubes 3a of the first tube row 2a with the hotter refrigerant. According to the invention, the inlet pipe 10 and the outlet pipe 12 are connected by at least one bypass ductas will be explained in more detail in the following by way of FIGS. 2 and 3so that the flat tubes 3a and 3b are preferably flowed through by the gaseous phase of the refrigerant. In this way, the distribution of the air temperature over the outlet area 16 can be equalisedas will still be explained in more detail in the following by way of FIG. 4and furthermore the heating-up of the air in the heat pump heater 1 intensified.

[0030] FIG. 2 shows a view of the connecting manifold 17 with the inlet base 9 and with the outlet base 11. In FIG. 3, a sectional view of the connecting manifold 17 is shown. Here, the connecting manifold 17 comprises the inlet pipe 10 and the outlet pipe 12 which are formed in the connecting manifold 17. The connecting manifold 17 can be embodied single-row and also multi-row. In addition, the inlet base 9 comprises multiple continuous inlet passages 9a, via which the flat tubes 3a of the first tube row 2a are fluidically connected to the inlet pipe 10. Analogously, the outlet base 11 comprises multiple continuous outlet passages 11b via which the flat tubes 3b of the second tube row 2b are fluidically connected to the outlet pipe 12.

[0031] Making reference to FIG. 3, the inlet pipe 10 and the outlet pipe 12 are fluidically connected to one another by bypass ducts 19. The mass flow of the liquid phase of the refrigerant can then be conducted through the bypass ducts 19 and does no longer pass the flat tubes 3a and 3b of the heat pump heater 1. By way of this, the mass flow of the gaseous phase in the flat tubes 3a and 3b can be increased. In particular, more heat can thereby be transferred in the tube block 4 to the air flowing through the tube block 4 and the distribution of the air temperature over the outlet area 16 of the tube block 4 improved or equalised.

[0032] In this exemplary embodiment, the bypass ducts 19 are each formed by a continuous bypass opening 20 in the connecting manifold 17. Here, the bypass openings 20 fluidically connect the inlet pipe 10 and the outlet pipe 12. Here, the bypass openings 20 are arranged in an end region 21 of the inlet pipe 10 which is located opposite the inlet opening 10a of the inlet pipe 10. In addition, the bypass openings 20 are arranged in a lower region 22 of the inlet pipe 10. The lower region 22 is arranged located opposite the inlet base 9 and extends over half a width of the inlet pipe 10 in the longitudinal direction of the flat tubes 3a or in a first flow direction 15a of the refrigerant. Through this advantageous arrangement of the bypass openings 20 it can be avoided that the gaseous phase of the refrigerant flows through the bypass openings and the performance of the heat pump heater 1 is thereby reduced. In this exemplary embodiment, the bypass openings 20 have a round cross section. A diameter D.sub.BP of the bypass openings 20 is preferably between 0.5 mm and 3.4 mm.

[0033] FIG. 4 shows a view of the heat pump heater 1 with the distribution of the air temperature on the outlet area 16. Here, the heat pump heater 1 was operated with the refrigerant having an oil proportion of 5% by mass in part load and the air temperature on entering the tube block 4 was around 15 C. On the outlet area 16, differences between the air temperature on entering the tube block 4 and on exiting the tube block 4 are each entered. Advantageously, the values over the outlet area 16 merely differ by a few C. so that a side-dependent distribution of the air temperature over the outlet area 16 in the heat pump heater 1 according to the invention is advantageously reduced significantly.

[0034] By comparison, FIG. 5 shows a view of a heat pump heater 25 according to the prior art. In contrast with the heat pump heater 1 according to the invention, the conventional heat pump heater 25 does not have a bypass duct. Otherwise, the construction of the heat pump heater 25 corresponds to the construction of the heat pump heater 1 according to the invention. As in FIG. 4, the heat pump heater 25 in this case was operated with the refrigerant having an oil proportion of 5% by mass in part load and the air temperature on entering the tube block was around 15 C. The values over the outlet area in the conventional heat pump heater 25 differ in contrast with the heat pump heater 1 according to the invention by up to 25 C., so that a side-dependent distribution of the air temperature over the outlet area in the heat pump heater 25 is substantial.