US20130055747A1

US20130055747A1 - Heating/Air-Conditioning Installation With External And Contiguous Condenser And Evaporator For Heating The External Evaporator

Info

Publication number: US20130055747A1
Application number: US13/698,941
Authority: US
Inventors: Patrick Bach
Original assignee: Peugeot Citroen Automobiles SA
Current assignee: PSA Automobiles SA
Priority date: 2010-05-25
Filing date: 2011-04-21
Publication date: 2013-03-07
Also published as: JP5991965B2; JP2013526458A; WO2011148071A1; EP2576255B1; FR2960628A1; CN103025550B; ES2534919T3; CN103025550A; BR112012029728A2; BR112012029728B1; EP2576255A1; FR2960628B1

Abstract

A heating/air-conditioning installation (IC) comprises a compressor (CP) capable of heating and pressurizing a refrigerant, an internal condenser (CDI) capable, in heating mode, of contributing towards the heating of an air known as interior air by exchange with the refrigerant coming from the compressor (CP), an external pressure reducer (DTE) capable, in heating mode, of cooling the refrigerant, and an external evaporator (EE) capable, in heating mode, of heating up the refrigerant coming from the external pressure reducer (DTE) by exchange of heat with an air known as exterior air to feed into the compressor (CP). This installation (IC) further comprises an external condenser (CDE) contiguous with the external evaporator (EE) and capable, in heating mode, of collecting the refrigerant coming from the internal condenser (CDI) to feed the external pressure reducer (DTE) and constitute a heat source for the contiguous external evaporator (EE), so as to reduce the probability of the latter (EE) icing up in the presence of exterior air at a low temperature.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is the US national stage under 35 U.S.C. §371 of International Application No. PCT/FR2011/050920 having an international filing date of Apr. 21, 2011, which claims the priority of French application 1054015 filed on May 25, 2010.

BACKGROUND

The invention relates to the heating/air conditioning installations that equip certain vehicles, such as automobiles, as well as certain buildings.
As is known to the person skilled in the art, certain heating/air conditioning installations include reversible heat pumps that are able to work both in a heating mode as well as in a cooling mode. In particular, for this effect, they comprise an internal condenser which, in the heating mode, contributes towards heating of interior air by exchange with a heated and pressurized refrigerant fluid, and an external evaporator which, in the heating mode, heats the cooled and depressurized refrigerant fluid by exchange with exterior air.
We will hereinafter understand “external” to indicate a device that is used in the heat exchange process with the exterior air (i.e. an external evaporator or an external pressure reducer that feeds an internal evaporator), and understand “internal” to indicate a device used in the heat exchange process with the interior air (such as for example an internal condenser or an internal evaporator or even an internal pressure reducer which is feeding an internal evaporator).
In the event in which it is cold or very cold, which is to say when the temperature of the exterior air is sub-zero or approaching zero degrees Celsius (0° C.), the contact between the exterior air and the partially cooled refrigerant, which comes from the internal condenser and which circulates in the external evaporator, frequently provokes icing of the external evaporator, which has a negative impact on the functioning and therefore renders the installation less effective.
Many solutions have been proposed to rectify this disadvantage.
Thus, a first solution, which is most notably described in the French Pat. No. FR 2525330, consists of associating conduits to the external evaporator that are dedicated to de-icing in which a heat transfer fluid coming from the cooling circuit (for example, from a vehicle motor) circulates. The disadvantage of this first solution lies in the fact that this requires an important modification of the external evaporator. Furthermore, it turns out to be very difficult to use when the heat transfer fluid is practically nonexistent or unavailable from an energy prospective in heating mode, as is notably the case in “all electric” or “hybrid” vehicles or in buildings.
A second solution, most notably described in the British Pat. No. GB 988874, consists of implanting the external evaporator within the same housing as the internal condenser, in such a manner that the external evaporator can be heated due to the refrigerant liquid that is circulating in the internal condenser. The disadvantage of this second solution lies in the fact that it is exceedingly inconvenient, or even impossible to implement in an automobile and has a negative impact on overall performance.
A third solution that is notably described in the U.S. Pat. No. 5,586,448 consists in the use of an additional electric radiator for the heating of a heat transfer fluid which circulates through the external evaporator. The disadvantage of this third solution lies in the fact that it requires not only a modification of the external evaporator, but also an additional electric heating device, which reveals itself to be very cumbersome and energy hungry (which is penalizing as regards range in the case of an electric or hybrid vehicle).

SUMMARY

The object of the invention is therefore to propose a heating/air conditioning installation that does not present all or parts of the aforementioned disadvantages.
In particular, in this vein, a heating/air conditioning installation or system is provided that comprises:

- A dedicated compressor for the heating and pressurization of a refrigerant fluid,
- A dedicated internal condenser which, in heating mode, will contribute to the heating of interior air through exchange with the refrigerant fluid coming from the compressor,
- A dedicated external pressure reducer which, in heating mode, will cool the refrigerant fluid (before it feeds the external evaporator),
- A dedicated external evaporator which, in heating mode, will heat the refrigerant fluid coming from the external pressure reducer by exchange of exterior air to feed the compressor, and
- An external condenser that is contiguous to the external and dedicated evaporator which, in heating mode, will collect the refrigerant fluid that comes from the internal condenser to feed the external pressure reducer and make up a heat source for the contiguous external evaporator, in such a manner as to reduce the probability that the external evaporator will ice up in the presence of an exterior air at a low temperature.
- The external condenser collects refrigerant fluid at its inlet that comes from the internal condenser in a partial gaseous and partially liquid form so as to provide, at its outlet, a refrigerant fluid in liquid form. At the inlet of the internal condenser, the refrigerant fluid is in gaseous form. The condensation of the refrigerant fluid from the gaseous phase towards the liquid phase is therefore carried out in two parts, a first part at the level of the internal condenser, which is followed by the second part at the level of the external condenser. When compared to a simple bit of hosing that transports the refrigerant fluid in liquid form, the presence of the external condenser allows the transmission of more calories and therefore more heat to the external evaporator, which further diminishes the risk of icing up of the external evaporator.

The heating/air conditioning installation can also feature other characteristics that can be taken either separately or in combination, and more in particular:

- Its external condenser and its external evaporator can make up two contiguous sub-units of a same heat exchanger or two independent and contiguous heat exchangers;
- It can feature a dedicated internal pressure reducer which, in refrigeration mode, will cool the refrigerant fluid, and a dedicated internal evaporator which, in refrigeration mode, will cool the interior air by exchange with the refrigerant fluid coming from the internal pressure reducer;
- Its external condenser can be dedicated, in refrigeration mode, to pre-cool the refrigerant fluid coming from the compressor by exchange with the exterior air, so as to supply the internal pressure reducer with pre-cooled refrigerant fluid;
- It can feature a first three-way valve which includes a first inlet coupled with the output of the compressor, a first outlet coupled with the input of the compressor and a second outlet coupled with a first inlet/outlet of the external condenser;
- It can feature a second three-way valve which includes an inlet coupled with the outlet of the internal condenser, an outlet coupled with the inlet of the internal evaporator, and inlet/outlet coupled to a second inlet/outlet of the external condenser;
- It can feature a third three-way valve which includes a first inlet coupled with the second outlet of the first valve, an outlet coupled with the inlet of the external pressure reducer, and an inlet/outlet coupled with the first inlet/outlet of said external condenser;
- It can feature a fourth three-way valve which includes a first inlet coupled with the outlet of the internal evaporator, a second inlet coupled with the outlet of the external evaporator, and an outlet coupled with the inlet of the compressor;
- Its internal condenser can be dedicated, in heating mode, to heat the interior air by exchange with the refrigerant fluid coming from the compressor;
- As an alternative, its internal condenser may be dedicated, in heating mode, to heat, by exchange with the refrigerant fluid which comes from the compressor, a heat transfer fluid which is destined to feed a dedicated air heater to heat the interior air by thermal exchange.

The invention furthermore proposes a vehicle, such as an automobile, which features a heating/air conditioning installation of the type described here above.
DESCRIPTION OF THE FIGURES
Other characteristics and advantages of the invention will be revealed upon examination of the following detailed description, as well as from the attached drawings, in which:
FIG. 1 illustrates a first embodiment in a schematic and functional form of a heating/air conditioning installation, in heating mode,
FIG. 2 illustrates a second embodiment in a schematic and functional form of a heating/air conditioning installation, in heating mode, and
FIG. 3 illustrates, in a schematic and functional form, the heating/air conditioning installation of FIG. 1, in refrigeration mode.
The attached drawings can, as the case may be, help to complement the invention, as well as to contribute to its definition.

DETAILED DESCRIPTION

The purpose of the invention is that of proposing a reversible heat pump heating/air conditioning installation (IC).
We consider hereinafter as a non-exhaustive example, that the heating/air conditioning installation (IC) belongs to an automobile, such as for example, a car, such as the “full electric” or “hybrid” type. However, the invention is not limited to this application. It does in fact involve any reversible heat pump type heating/air conditioning installation, no matter whether it is destined to be installed in a vehicle or a building.
Two embodiments of heating/air conditioning installations IC, according to the invention, are schematically represented in FIGS. 1-3. The first embodiment, illustrated in FIGS. 1 and 3, is, for example, destined to be installed in an electric automobile or in a building. The second embodiment, illustrated in FIG. 2 is for example destined to be implanted in a hybrid automobile.
The heating/air conditioning installation IC is destined to work, as required, in heating or refrigeration mode. In particular, for this purpose, it features a compressor CP, an internal condenser CDI, an external pressure reducer DTE, an external evaporator EE, and an external condenser CDE that all are used, at least, in the heating mode.
The compressor CP heats and pressurizes a refrigerant fluid which, in heating mode, comes from the external evaporator EE.
The internal condenser CDI is only used in the heating mode. It contributes to the heating of the interior air (which here comes from the interior of the vehicle cabin) by exchange with the refrigerant fluid transformed into hot and pressurized gas by the compressor CP. At its outlet, it delivers a refrigerant fluid in liquid phase that has been partially cooled during exchange with the interior air.
In the example illustrated in FIGS. 1 and 3, the internal condenser CDI is of the gas/air type. It is therefore used to heat the interior air which passes through it by exchange with the refrigerant fluid (hot and pressurized gas) which circulates in its conduits or between its stacked panels.
In the example illustrated in FIG. 2, the internal condenser CDI is of the gas/liquid type. It therefore heats a heat transfer fluid, which circulates in some of its conduits or between certain parts of its stacked panels and which comes from a cooling circuit, by exchange with the refrigerant fluid (hot and pressurized gas) which circulates in certain other of its conduits or between certain other parts of its stacked panels. This heated heat transfer fluid then returns to the cooling circuit to feed a pump PE, which feeds an air heater AR which, in heating mode, heats the interior air which passes through it by exchange with the heated heat transfer fluid. Conventionally, the heat transfer fluid which flows out of the air heater AR feeds the portion of the cooling circuit which passes through the motor MR and which feeds the internal condenser CDI.
Herein, “air heater” is understood to mean an air/liquid heat exchanger. Furthermore, one will note that the air heater AR can form part of the installation IC.
The external pressure reducer DTE is only used in the heating mode. It cools and depressurizes the refrigerant fluid which comes from the external condenser CDI, before it feeds the external evaporator EE. It delivers a depressurized and cooled liquid.
The external evaporator EE is only used in the heating mode. It is used in heating the refrigerant fluid (depressurized and cooled liquid) which comes from the external pressure reducer DTE, by exchange with the exterior air (cold), which is to say absorption of heat contained in the exterior air. It delivers a refrigerant fluid at the outlet, in gaseous and lightly heated phase, which is destined to feed the compressor CP.
The external condenser CDE is contiguous with the external evaporator EE.
Herein, “contiguous” is understood to be the fact of being in contact with the external evaporator EE, or in the immediate vicinity of the external evaporator, most typically within a few centimeters, or rather interlocked in the external evaporator EE.
The external condenser CDE, in heating mode, collects the refrigerant fluid, which comes from the internal condenser CDI, so as to feed together with this refrigerant fluid, the external pressure reducer DTE and constitutes a heat source for the contiguous external evaporator EE. One will then understand that this source of heat (which is made up of the external condenser CDE) is such that it will reduce the probability that the external evaporator EE will ice up in the presence of an exterior air whose temperature is low.
Herein, “reducing the probability of icing” is understood to be the fact of limiting, as much as is possible, the creation of icing as regards the external evaporator EE. Typically, icing up will only be able to occur in the presence of a low exterior temperature, with a high level of humidity and a low exterior air speed.
It is important to note that the heating of the external evaporator EE can be undertaken by thermal conduction, in the case of an interlocking, or mechanical contact, with the external condenser CDE, and/or by means of the exterior air which has been heated during its passing through the external condenser CDE (which requires that the external condenser be placed upstream of the external evaporator EE vis-â-vis the flow of exterior air, as illustrated).
One will note that the external condenser CDE and the external evaporator EE may constitute two contiguous sub-units (preferably, interlocking) of a single heat exchanger or two independent and contiguous heat exchangers.
One will also note that the external condenser CDE may also function in the cooling mode. In such a case, the installation must also include an internal pressure reducer DTI and an internal evaporator EI, as illustrated in FIGS. 1-3.
The internal pressure reducer DTI is only used in the cooling mode. It cools and pressurizes the refrigerant fluid (in liquid phase), which comes from the external condenser CDE, before it arrives at the internal evaporator EI.
The internal evaporator EI also is only used in the cooling mode. It is used to cool the interior air which passes through it by thermal exchange with the cooled and depressurized refrigerant fluid (in liquid phase) which comes from the internal pressure reducer DTI.
In the cooling mode, the external condenser CDE is used to pre-cool the refrigerant fluid (hot and pressurized gas), which comes from the compressor CP, by thermal exchange with the exterior air, so as to feed the internal pressure reducer DTI with pre-cooled refrigerant fluid (in liquid phase).
So as to facilitate the verification of the functioning of the installation IC, as well as to also limit its footprint, the heating/air-conditioning installation (IC) can include at least one of the three-way valves Vj, that are described here-below:

- first valve V1 (j=1) that features an inlet coupled to the outlet of the compressor CP, a first outlet coupled with the inlet of the internal condenser CDI and a second outlet coupled with a first inlet/outlet of the external condenser CDE.
- second valve V2 (j=2) that features an inlet coupled to the outlet of the internal condenser CDI, an outlet coupled with the inlet of the internal evaporator EI and an inlet/outlet coupled with a second inlet/outlet of the external condenser CDE.
- A third valve V3 (j=3) that features a first inlet coupled with the second outlet of the first valve V1, an outlet coupled to the inlet of the pressure reducer DTE, and an inlet/outlet coupled to the first inlet/outlet of the external condenser CDE.
- A fourth valve V4=4) featuring a first inlet coupled with an outlet of the internal evaporator EL a second inlet coupled with the outlet of the external evaporator EE, and an outlet coupled with the inlet of the compressor CP.

One will also note that, as is illustrated in a non-exhaustive manner in FIGS. 1-3, the installation IC can optionally include one or more dehydrating reservoirs RD1, RD2. In the examples illustrated, the installation IC features a first dehydration reservoir RD1 positioned between the first inlet/outlet of the external condenser CDE and the inlet of the external pressure reducer DTE, and a second dehydration reservoir RD2 positioned between the second inlet/outlet of the external condenser CDE and the inlet of the internal evaporator EI.
The mode of heating of the installation IC is symbolized by arrows in FIGS. 1-2. In this heating mode, the refrigerant fluid circulates from the compressor CP towards the internal condenser CDI where it is used (FIG. 1) or simply contributes (FIG. 2) to the heating of the interior air by thermal exchange. The first valve V1 is then configured in such a way that the refrigerant fluid is directed towards the internal condenser CDI. Thereafter, the refrigerant fluid goes from the internal condenser CDI towards the external condenser CDE, by way of the second valve V2 which is configured for this purpose. It then heats the contiguous external evaporator EE and thereby permits that it is either not or only slightly iced up. Then the refrigerant fluid goes from the external condenser CDE towards the external pressure reducer DTE, by way of a third valve V3 which is configured for this purpose. It is then partially cooled and depressurized. Then, the refrigerant fluid goes from the external pressure reducer DTE towards the external evaporator EE where it is cooled by thermal exchange with the exterior air. Lastly, the refrigerant fluid goes from the external evaporator EE towards the compressor CP where it is transformed in to heated and pressurized gas, by way of a fourth valve V4 which is configured for this purpose.
The cooling mode of the installation IC is symbolized by arrows in FIG. 3. In this cooling mode, the refrigerant fluid circulates from the compressor CP towards the external condenser CDE where it is partially cooled by thermal exchange with the exterior air. The first valve V1 and the third valve V3 are configured for this purpose. Then, the refrigerant fluid goes from the external condenser CDE towards the internal pressure reducer DTI where it is cooled and depressurized, by way of the second valve V2 which is configured for this purpose. Then, the refrigerant fluid goes from the internal pressure reducer DTI towards the internal evaporator EI where it cools the interior air that passes through the same (EI) by thermal exchange. Then, the refrigerant fluid goes from the internal evaporator EI towards the compressor CP where it is transformed in heated and pressurized gas, by way of the valve V4 which is configured for this purpose.
The invention offers a certain number of advantages, amongst which:

- It does not require any additional heating device, which is particularly advantageous in the event of fitting in an all-electric or hybrid system.
- It allows for the improvement of the yield (performance coefficient) of the thermodynamic cycle of the installation when the exterior temperature is cold, or rather very cold, without noticeably increasing its complexity, all the while decreasing the enthalpy at the inlet of the external evaporator, thereby permitting one to increase the evaporation energy of the latter while maintaining the same throughput of refrigerant fluid and therefore with the same quantity of consumed energy.

The invention does not limit itself to methods of execution of the heating/air conditioning installation and of the vehicle described here above, in a non-exhaustive manner, but rather encompasses all variants that could be foreseen by the person skilled in the art within the framework of the claims that follow.

Claims

1. A heating/air conditioning system comprising a compressor (CP) adapted to heat and pressurize a refrigerant fluid, an internal condenser (CDI) capable, in a heating mode, to contribute to the heating of interior air by exchange with said refrigerant fluid coming from said compressor (CP), an internal pressure reducer (DTE) capable, in a heating mode, to cool said refrigerant fluid coming from said external pressure reducer (DTE) by exchange with exterior air to feed said compressor (CP), characterized in that it further comprises an external condenser (CDE) that is contiguous with said external evaporator (EE) which is capable, in a heating mode, of collecting said refrigerant fluid coming from said internal condenser (CDI) to feed said external pressure reducer (DTE) and constitute a heat source for said contiguous external evaporator (EE), in such a manner as to reduce the probability that the external evaporator (EE) will ice up in the presence of exterior air that presents a low temperature.

2. The system according to claim 1, characterized in that said external condenser (CDE) and said external evaporator (EE) make up two contiguous sub-units of a single heat exchanger.

3. The system according to claim 1, characterized in that said external condenser (CDE) and said external evaporator (EE) make up two independent and contiguous heat exchangers.

4. The system according to claim 1, characterized in that it said system comprises an internal pressure reducer (DTI) capable, in a cooling mode, to cool said refrigerant fluid, and an internal evaporator (EI) capable, in a cooling mode, to cool said interior air by exchange with said refrigerant fluid coming from said internal pressure reducer (DTI).

5. The system according to claim 4, characterized in that said external condenser (CDE) is capable, in a cooling mode, to pre-cool said refrigerant fluid coming from said compressor (CP) by exchange with said exterior air, so as to feed said internal pressure reducer (DTI) with pre-cooled refrigerant fluid.

6. The system according to claim 1, characterized in that it said system includes a first three-way valve (V1) including an inlet coupled with the outlet of said compressor (CP), a first outlet coupled with the inlet of said internal condenser (CDI) and a second outlet coupled with a first inlet/outlet of said external condenser (CDE).

7. The system according to claim 6, characterized in that it the system includes a second three-way valve (V2) including an inlet coupled with an outlet of said internal condenser (CDI), an outlet coupled with the inlet of said internal evaporator (EI), and an inlet/outlet coupled with a second inlet/outlet of said external condenser (CDE).

8. The system according to claim 7, characterized in that it contains a third three-way valve (V3) including a first inlet coupled with a second outlet of said first valve (V1), an outlet coupled to the inlet of said external pressure reducer (DTE), and an inlet/outlet coupled with said first inlet/outlet of said external condenser (CDE).

9. The system according to claim 8, characterized in that the system includes a fourth three-way valve (V4) including a first inlet coupled with the outlet of said internal evaporator (EI), a second inlet coupled with the outlet of said external evaporator (EE), and an outlet coupled with the inlet of said compressor (CP).

10. The system according to claim 1, characterized in that said internal condenser (CDI) is capable, in a heating mode, to heat said interior air by exchange with said refrigerant fluid coming from said compressor (CP).

11. The system according to claim 1, characterized in that said internal condenser (CDI) is capable, in a heating mode, to heat, by exchange with said refrigerant fluid coming from said compressor (CP), a heat transfer fluid destined to feed a dedicated air heater (AR) to heat said interior air by thermal exchange.

12. A vehicle characterized in that it includes a heating/air conditioning system, said heating/air conditioning system comprising a compressor (CP) adapted to heat and pressurize a refrigerant fluid, an internal condenser (CDI) capable, in a heating mode, to contribute to the heating of interior air by exchange with said refrigerant fluid coming from said compressor (CP), an internal pressure reducer (DTE) capable, in a heating mode, to cool said refrigerant fluid coming from said external pressure reducer (DTE) by exchange with exterior air to feed said compressor (CP), characterized in that it further comprises an external condenser (CDE) that is contiguous with said external evaporator (EE) which is capable, in a heating mode, of collecting said refrigerant fluid coming from said internal condenser (CDI) to feed said external pressure reducer (DTE) and constitute a heat source for said contiguous external evaporator (EE), in such a manner as to reduce the probability that the external evaporator (EE) will ice up in the presence of exterior air that presents a low temperature.