U.S. patent application number 10/802194 was filed with the patent office on 2004-11-25 for heat exchanger assembly.
This patent application is currently assigned to VISTEON GLOBAL TECHNOLOGIES, INC.. Invention is credited to Antonijevic, Dragi, Heckt, Roman.
Application Number | 20040231825 10/802194 |
Document ID | / |
Family ID | 32946140 |
Filed Date | 2004-11-25 |
United States Patent
Application |
20040231825 |
Kind Code |
A1 |
Heckt, Roman ; et
al. |
November 25, 2004 |
Heat exchanger assembly
Abstract
A heating heat exchanger in a coolant circuit for motor vehicles
is provided whereby the air to be heated can be additionally heated
by a refrigerant circuit, operable as heat pump or short circuit,
for additional heating. A gas cooler/condenser for the additional
heating operation and a functionally separated evaporator for the
cooling plant operation of the refrigerant circuit are provided,
whereby the heat exchanger surfaces of the gas cooler/condenser for
the additional heating operation are integrated into the heating
heat exchanger and in additional heating operation are integrated
into the heating heat exchanger and in additional heating operation
the air to be heated is simultaneously heated by the heating heat
exchanger and the gas cooler/condenser.
Inventors: |
Heckt, Roman; (Aachen,
DE) ; Antonijevic, Dragi; (Koln, DE) |
Correspondence
Address: |
VISTEON
C/O BRINKS HOFER GILSON & LIONE
PO BOX 10395
CHICAGO
IL
60610
US
|
Assignee: |
VISTEON GLOBAL TECHNOLOGIES,
INC.
|
Family ID: |
32946140 |
Appl. No.: |
10/802194 |
Filed: |
March 17, 2004 |
Current U.S.
Class: |
165/42 ;
165/175 |
Current CPC
Class: |
F28D 1/0435 20130101;
B60H 1/00899 20130101; F28D 2021/0073 20130101; F28F 2009/0287
20130101; B60H 1/00328 20130101 |
Class at
Publication: |
165/042 ;
165/175 |
International
Class: |
B60H 003/00; B61D
027/00; F28F 009/02; F25B 041/00; F25B 049/00 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 17, 2003 |
DE |
DE 103 13 234.1 |
Claims
1. A heat exchanger assembly for motor vehicles, whereby the air to
be heated can be additionally heated by a refrigerant circuit
operable as heat pump or short circuit for additional heating, said
assembly comprising: a heating heat exchanger in a coolant circuit,
a gas cooler/condenser having first heat exchanging surfaces for
the additional heating operation and second heat exchanging
surfaces for the cooling plant operation of the refrigerant
circuit, said first heat exchanging surfaces being integrated into
the heating heat exchanger and during additional heating operation
the air to be heated is simultaneously heated by said heating heat
exchanger and said first heat exchanging surfaces of said
cooler/condenser.
2. The assembly of claim 1 wherein in additional heating operation
the coolant circuit and the refrigerant are controlled by a
controller such that heat exchanger surfaces of the heating heat
exchanger and said first heat exchanging surfaces of said gas
cooler/condenser/evaporator in additional heating operation have
temperature differences of less than 25 K.
3. The assembly of claim 1 wherein said heating heat exchanger
includes at least two rows of coolant tubes and said first heating
surfaces include at least one row of refrigerant tubes, said
coolant tubes and said refrigerant tubes being arranged after each
other in direction of the passing air.
4. The assembly of claim 3 wherein said coolant tubes and said
refrigerant tubes are arranged next to each other and are parallely
passed by air.
5. The assembly of claim 4 wherein said coolant tubes and
refrigerant tubes are arranged alternating next to each other.
6. The assembly of claim 1 further comprising a collector unit
having a coolant collector region and a refrigerant collector
region, whereby said refrigerant collector region is partly
surrounded by said coolant collector region.
7. The assembly of claim 1 further comprising a collector unit
having a coolant region and a refrigerant collector region, whereby
said refrigerant collector region has no common boundary surface
with said coolant region and is arranged thermally separated from
said coolant collector region.
8. The assembly of claim 7 wherein alternatingly, partly instead of
coolant tubes, refrigerant tubes are arranged comb-like in a row of
the heating heat exchanger and the refrigerant collector regions
are connected over connection tubes to the refrigerant tubes and
because the refrigerant collector regions are arranged outside of
the coolant collector region the resulting comb design realizes a
good thermal separation of the coolant circuit and the refrigerant
circuit.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to a heat exchanger in a coolant
circuit of a motor vehicle and system to heat the passenger
compartment.
[0003] 2. Related Art
[0004] The trend towards highly efficient motor vehicle drive
systems has resulted in a lack of sufficient waste heat for heating
the interior of the vehicle. Therefore, the comfort conditions get
worse in vehicles in which the passenger compartment is heated
solely based on the engine's coolant circuit.
[0005] In the state-of-the-art there are many approaches to solve
this problem. For example, the cooling circuit can be electrically
heated or the air of the vehicle interior can be directly heated by
means of PTC resistors. Additionally, fuel-fired supplemental
heating devices for the coolant circuit are known.
[0006] An alternative development to supplemental heating devices
is to use the refrigerant systems, or air conditioning units,
present in motor vehicles for the heating of the vehicle interior.
This is possible by operating the air conditioning unit as heat
pump. Alternatively, a "short" circuit, without secondary heat
absorption in the clockwise-rotating version or
anticlockwise-rotating version, can be used. In a short circuit,
essential portions of the mechanical drive power of the compressor
are transformed into heat for the purpose of heating the passenger
compartment. Such air conditioning units are also known.
[0007] When an air conditioning unit in a vehicle is used for
additional heating, a highly undesirable effect occurs under
certain use and environmental conditions. Particularly, when the
refrigerant system is used as a cooling plant, the evaporator
arranged in the ventilating system of the vehicle will dehumidify
the air to be cooled. After having stopped the engine and starting
it anew when the heat exchanger has previously been used as
evaporator and now is subsequently used as condenser or gas cooler
in heating modes, due to heat being given off to the air flow, the
humidity condensed on the evaporator surface will be introduced
into the vehicle interior. Alternating use of the system as cooling
plant and heat pump is quite frequent in the transitional weather
periods, such as Spring and Autumn.
[0008] The high humidity air led into the vehicle interior results
in condensation on the cold interior surfaces of the vehicle,
particularly on the windows, with accompanying deterioration of the
passengers' sight. This effect is also called flash-fogging.
[0009] In the state-of-the-art, solutions exist that are intended
to prevent this effect.
[0010] After a special form of construction for the refrigerant
carbon dioxide, in DE 198 55 309 an additional heating device for
vehicles is disclosed. Here the gas cooler, or condenser,
respectively, is divided into different regions, alternatingly used
for cooling or heating. First, there is an evaporator region, which
in cooling plant operation cools and, accordingly, dehumidifies the
air flowing into the vehicle interior. Second, another region, in
heat pump operation, heats the air flowing into the vehicle
interior. This functional separation ensures that the air condensed
on the evaporator will not, or only a little, be re-absorbed by the
air flowing into the vehicle interior, thereby reducing possibility
of flash fogging.
[0011] In DE 198 55 309, the heating heat exchanger is combined
with the additional heating device from the refrigerant circuit for
heating in such a way that the heat exchangers are switched in
series. However, this results in the disadvantage that even more of
the limited space available in the ventilation plants of motor
vehicles is required by such a series connection.
[0012] Therefore, it is the objective of the invention to provide a
heating heat exchanger, which requires little space and enables an
advantageous control behavior and lowest possible flow
resistance.
BRIEF SUMMARY OF THE INVENTION
[0013] According to the invention, the problem is solved by a
heating heat exchanger in a coolant circuit for vehicles, whereby
the air to be heated can be additionally heated by means of a
refrigerant circuit operable as heat pump or short circuit to
provide the additional heating. A gas cooler/condenser for the
additional heating and a functionally separated evaporator for
cooling plant operation of the refrigerant circuit are provided,
whereby the heat exchanger surfaces of the gas cooler/condenser for
additional heating operation are integrated into the heating heat
exchanger and the air to be heated during additional heating
operation is simultaneously heated by the heating heat exchanger
and the gas cooler/condenser.
[0014] As used herein, additional heating operation means that
operational mode, in which the refrigerant circuit, e.g. operating
in a heat pump circuit or a short circuit, is used for additional
heating of the vehicle's passenger compartment.
[0015] The combination of the invention is realized with particular
advantage, when the refrigerant circuit and the coolant circuit in
additional heating operation are controlled such that the heat
exchanger surfaces of the heating heat exchanger and the gas
cooler/condenser have differences in temperature of less than 25 K
during the additional heating operation.
[0016] One aspect of the invention is in the separation of the
functions of the heat exchangers in additional heating operation
and the integration of the component for the heating of the air
into the heating heat exchanger of the coolant circuit.
[0017] Advantages include, without limitation, the avoidance of the
flash-fogging and the possibility to space-savingly realize
functional separation in heat exchanger components of the
refrigerant circuit.
[0018] The combined use of the heat exchanger surfaces of coolant
circuit and refrigerant circuit in the heat exchanger enables the
invention to obtain the functionality of additional heating by
means of a switched-over refrigerant circuit without additional
space demand in a ventilating plant and without the risk of flash
fogging.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Other details, features and advantages of the invention
ensue from the following description of embodiment examples with
reference to the accompanying drawings. The figures show:
[0020] FIG. 1--schematic of the refrigerant and coolant circuit
combination;
[0021] FIG. 2--heating heat exchanger with integrated gas
cooler/condenser;
[0022] FIG. 3--collector unit;
[0023] FIG. 4--collector unit with integrated refrigerant
collector;
[0024] FIG. 5--collector unit with externally arranged refrigerant
collector;
[0025] FIG. 6--gas cooler/condenser-heat exchanger component in
comb design;
[0026] FIG. 7--heating heat exchanger with integrated gas
cooler/condenser in three-dimensional view.
DETAILED DESCRIPTION OF THE INVENTION
[0027] In FIG. 1 the concept of a refrigerant and coolant circuit
combination is schematically illustrated. A heating heat exchanger
3 of coolant circuit 1 and gas cooler/condenser 4 of a refrigerant
circuit 2 are combined such that the heat exchanger surfaces of the
heating heat exchanger 3 and the gas cooler/condenser 4 are
simultaneously passed by the air to be heated 5 in heat pump
operation. The undesired mutual influence of the coolant and
refrigerant circuits 1, 2 is minimized in that the circuits are
controlled without significant power loss such that the temperature
difference between the heat exchanger surfaces is less than 25
K.
[0028] FIG. 2 shows a heating heat exchanger 3 with integrated gas
cooler/condenser. The heating heat exchanger 3 includes coolant
tubes 6 and refrigerant tubes 7 alternatingly arranged side by
side, which are parallelly passed by the air to be heated. Between
the coolant tubes 6 and refrigerant tubes 7 cellular blocks 11 are
provided, which enlarge the heat exchanger surface. In the example
of embodiment shown the coolant and refrigerant collector regions
9, 10 are placed at the heat of the heating heat exchanger 3. The
term collector, or collector region, respectively, is, with the
corresponding function in reversed sense, also meant as
distributor, or distributor region, respectively, without special
reference.
[0029] In the example shown, the coolant and similarly the
refrigerant of the coolant circuit 1 are distributed in the coolant
collector region or coolant distributor region 9 of the distributor
unit into the coolant tubes 6, pass the coolant tubes 6 dissipating
heat to the cellular blocks 11 in thermal contact with the coolant
tubes 6 and the air to be heated 5. In the redirection region 14 of
the coolant tubes 6 it is redirected by 180.degree. and flows in
opposite direction back to the coolant collector region 9, where
the coolant is collected and passed on. The 180.degree. redirection
of the refrigerant takes place similarly in the helix-shaped
redirection region 12 of the refrigerant tubes 7.
[0030] In FIG. 3 a collector unit 8 for a heating heat exchanger 3
with separate collector and distributor units is shown. The
collector unit 8 has a coolant collector region 9 and a refrigerant
collector region 10 with the refrigerant collector region 10 partly
surrounded by the coolant collector region 9. The coolant tubes 6,
configured as flat tubes, lead into the coolant collector region 9
of the collector unit 8. The refrigerant tubes 7, configured as
flat tubes with channels for the refrigerant, penetrate the coolant
collector region 9 and lead into the refrigerant collector region
10, which is separated from the coolant collector region 9, within
the collector unit 8. According to the shown preferred embodiment
of the invention, two layers of coolant tubes 6 and refrigerant
tubes 7 are provided in each case, whereby the refrigerant tubes 7
are only arranged within one layer of the coolant tubes 6.
[0031] The FIGS. 4 and 5 represent different embodiments of the
design of the collector unit 8. In FIG. 4 a collector unit 8 with
refrigerant collector region 10 integrated into the coolant
collector region 9 is shown. In FIG. 5, an embodiment of a
collector unit 8 is shown, the refrigerant collector region 10 of
which is arranged outside of the coolant collector region 9.
[0032] From the above, a concept is realized, in which the
refrigerant collector region 10 has no common boundary surface with
the coolant collector region 9 and, hence, is thermally separated
from it located outside of the coolant collector region 9. Thus an
undesired heat flow from the coolant circuit 1 to the refrigerant
circuit 2 and vice versa is prevented. In the shown embodiment of
the invention, the refrigerant tubes 7 penetrate the coolant
collector region 9. An advantageous modification of the invention
consists in the refrigerant tubes 7 being installed in a wider arc
around the coolant collector region 9 and therefore no direct
thermal contact through heat conduction to the coolant collector
region 9 exists.
[0033] In FIG. 6 another advantageous embodiment, characterized by
a comb design, is shown. The heating heat exchanger 3 is configured
as usual in the state-of-the-art modified in that some coolant
tubes 6 are omitted to make space for refrigerant tubes 7. The
refrigerant collector region 10 are connected to the refrigerant
tube 7 over connection tubes 13. Due to the fact that the
refrigerant collector regions 10 are arranged outside of the
coolant collector region 9, the resulting comb design realizes a
good thermal separation of the coolant circuit 1 from the
refrigerant circuit 2.
[0034] According to FIG. 7 a three-dimensional view of another
advantageous embodiment is proposed and in which the combination of
different geometries of refrigerant and coolant tubes 7, 6 is
elucidated. Two layers, or rows, of coolant tubes 6 are arranged
after each other in direction of the passing air. Within one layer
of coolant tubes 6, alternating refrigerant tubes 7 are arranged,
whereby the refrigerant tubes 7 again are arranged in two layers
after each other in direction of the passing air.
[0035] The heat exchanger unit of the refrigerant, which is
integrated into one row of the coolant heat exchanger, can be
placed on the air inflow side or air outflow side depending on the
chosen configuration of additional heating by the refrigerant
circuit.
[0036] Further, concerning the arrangement and type of coolant
circuits, known in the state-of-the-art for cross flow, cross
countercurrent flow and cross co-current flow as well as parallel
flow and co-current flow can be used advantageously depending on
the thermal states and space conditions.
* * * * *