JP5716157B2 - Air conditioning system for automobile cabin - Google Patents

Description

  The present invention relates to an air conditioning system for a passenger compartment of an automobile, for example, an industrial vehicle.

  Air conditioning systems have been a standard feature of automobiles for many years.

  Such systems typically include a refrigerant circuit that carries the refrigerant within the loop. Conventionally, the gas-phase refrigerant is compressed into a high-pressure gas in a compressor driven by an automobile engine or a dedicated motor. At the outlet of the compressor, the refrigerant is hot due to compression. The refrigerant is then transported towards a condenser, which may be located at the front of the vehicle or in some other location where it can come into contact with ambient air, in which it is cooled and condensed. Maintains high pressure while becoming liquid. A condenser is essentially a heat exchanger between high pressure refrigerant and ambient air. In order to increase the condensation efficiency, a condenser fan, driven by an automobile engine or driven by a separate electric motor, is generally placed in close proximity to the condenser. The liquid phase but high pressure refrigerant is then expanded in the expander, where the temperature of the refrigerant drops sharply and then is transported towards the evaporator where it evaporates into a gas and again. Enter the compressor. In order to lower the passenger compartment temperature, the air flow introduced into the passenger compartment is cooled by utilizing the evaporation of the refrigerant in the evaporator. The evaporator is essentially a heat exchanger between the low-pressure refrigerant and the air blown into the passenger compartment. Of course, various types of air conditioning systems are based on this principle, but various elements may vary from embodiment to embodiment. For example, the expander may simply be a calibration orifice flow path or a temperature expansion valve. In the former case, the system may further include an accumulator between the evaporator and the compressor, and in the latter case, the system further includes a storage dryer between the condenser and the expander. There is.

  Under some operating conditions, such conventional air conditioning systems may have insufficient efficiency or require excessive power to achieve the expected cooling effect. This can happen when the outside temperature is high or when the car is moving at low speed, for example in a city.

  One solution to increase system efficiency is to operate the system with recirculated air. In other words, the air flow cooled by the evaporator and guided toward the passenger compartment is not the outside air but the air coming from the passenger compartment. Since the recirculated air is not as warm as the outside air, less energy is required to reach the target temperature in the passenger compartment. As a result, fuel consumption is reduced, temperature targets are achieved quickly, and driver comfort in terms of temperature is increased.

  However, one function of the evaporator is to dry the air that it cools, and since only a little or no outside air is taken in, the humidity in the passenger compartment gradually decreases as one by-product of this measure. . As a result, the humidity in the passenger compartment can be very low, which is undesirable because it can be uncomfortable for the driver, especially if the driver is wearing contact lenses.

  Therefore, there is room for improvement in the air conditioning system for automobiles from several viewpoints.

  It is an object of the present invention to provide an improved air conditioning system for a vehicle cabin that can overcome the disadvantages found in conventional air conditioning systems.

  Another object of the present invention is to provide an air conditioning system that has high efficiency while still being comfortable for the driver, more generally for the person in the passenger compartment.

In order to solve the above problems, an air conditioning system according to the present invention includes:
An air conditioning system for an automobile compartment (2) comprising an air flow (10) directed towards a compressor (4), a condenser (5), an expander (8) and said compartment (2). In an air conditioning system comprising a refrigerant circuit (3) carrying refrigerant in a loop continuously passing through an evaporator (9) capable of cooling):
A collector (12) that collects the condensate that is found in the evaporator (9) during use, and enables thermal contact between the condensate and the refrigerant so that the refrigerant is cooled by the condensate. A recovery tube (13) carrying the condensate towards a heat exchanger (5) designed to heat the condensate,
Provided between the heat exchanger (5) and the passenger compartment (2), in order to humidify the passenger compartment (2), at least a part of the condensate heated by the heat exchanger is used as the vehicle. And a return pipe (14) for carrying into the chamber (2).

  The heat exchanger may be a dedicated heat exchanger that is arranged at some point in the air conditioning circuit where the refrigerant becomes hot, preferably downstream of the compressor and upstream of the expander.

  Nevertheless, according to two embodiments described in more detail below, the heat exchanger is integrated with the condenser. For this reason, in such a case, the present invention provides a three-fluid heat exchange that forms a condenser in which the refrigerant is the first fluid, the environmental air is the second fluid, and the condensate of the evaporator is the third fluid. It becomes a vessel. In other words, the refrigerant is cooled in the condenser under the action of two cooling sources, ambient air and condensate, and heating of these cooling sources contributes to cooling of the refrigerant.

  With this configuration, the efficiency of the air conditioning system is greatly improved. Thus, the system can provide sufficient cooled air into the passenger compartment even on hot days or when the car is moving at low speed. The present invention makes it possible to achieve this effect without having to rotate the condenser fan for a long time, thus contributing to a reduction in fuel consumption. Furthermore, by increasing the system efficiency, the present invention also allows the target temperature in the passenger compartment to be reached more quickly.

  Yet another advantage of the present invention is the amount of water discharged to the ground that induces condensate, which can cause rust in the part of the vehicle where it flows and also marks the ground. Is to be minimized. Furthermore, considering that the volume of water condensed per hour can be very large, especially in countries with high temperatures and high humidity, the present invention utilizes condensate that would otherwise be lost. Is.

  Furthermore, once the condensate is heated in the heat exchanger, it is not sent to the atmosphere, but is preferably sent to the passenger compartment in the form of steam and / or heated humidified air. This is particularly the case when the air conditioning system uses recirculated air from the passenger compartment, but is not limited to this case, and helps to maintain the humidity in the passenger compartment at a comfortable level.

  An important aspect of the present invention is to cool the condenser with condensate to improve its efficiency when the size of the condenser is the same, or alternatively, the efficiency of the condenser is the same. , It is possible to reduce its size, or to combine both effects, which was not achievable with prior art systems. Using a smaller condenser at the front of the vehicle may be advantageous in some vehicles.

  The present invention provides an air conditioning system that can provide sufficient cooling efficiency even when a refrigerant that may be less effective is used, in compliance with future regulations.

  The invention also relates to a motor vehicle having a passenger compartment and such an air conditioning system.

  These and other features and advantages will become apparent upon reading the following description in light of the accompanying drawings, which illustrate, by way of non-limiting example, embodiments of an air conditioning system according to the present invention.

  The following detailed description of several embodiments of the present invention can be better understood when read in conjunction with the appended drawings, but the invention is not limited to these specific disclosed embodiments. Please understand that it is not.

1 is a schematic diagram of an air conditioning system according to the present invention. 2 is a schematic diagram of the air conditioning system of FIG. 1 showing more specifically a circuit of condensed water and water vapor. 1 is a schematic diagram showing a prior art condenser. 1 is a schematic diagram showing a prior art condenser. 1 is a diagram of a conduit used in a first embodiment of a condenser of an air conditioning system according to the present invention. FIG. 1 is a diagram of a conduit used in a first embodiment of a condenser of an air conditioning system according to the present invention. FIG. It is a detailed sectional view of the condenser according to the first embodiment. It is a detailed perspective view of the condenser according to the first embodiment. It is a schematic sectional drawing which shows a part of condenser which concerns on the 2nd Embodiment of this invention.

As shown in FIGS. 1 and 2, an air conditioning system 1 for a passenger compartment 2 of an automobile first includes a refrigerant circuit 3 that carries refrigerant in a loop.

  In the refrigerant circuit 3, the refrigerant enters the compressor 4 driven by an automobile engine or a dedicated motor as low-pressure gas. After the compressor 4, the high-pressure and high-temperature gaseous refrigerant is directed to a condenser 5 that is disposed at the front of the vehicle and condenses the refrigerant into a high-pressure liquid. A fan 6 driven by an automobile engine or a separate motor can be provided close to the condenser 5 to increase the efficiency of the condenser. In this embodiment, the refrigerant flows towards the storage dryer 7 and then flows through the expander 8 which is here implemented as a temperature expansion valve. A pressure sensor can be provided in the circuit between the storage dryer 7 and the expander 8. In the inflator, the high pressure liquid is expanded and the pressure is reduced, thus causing the temperature to drop significantly. The low pressure refrigerant then enters the evaporator 9 where it evaporates into a low pressure gas. This gaseous refrigerant then flows again towards the compressor 4.

  In the evaporator 9, the air flow 10 is cooled by using the evaporation of the refrigerant, and this air flow is sent toward the passenger compartment 2 using a blower, for example. In contrast, the air flow heats the refrigerant and thus promotes its evaporation.

  The air conditioning system 1 according to the present invention is further integrated with a collector 12 for collecting condensate that may be found in the evaporator 9 during use, and with the condenser 5 in any of the embodiments described below. And a recovery tube 13 for carrying the condensate towards the heat exchanger to be converted. Since the air in contact with the evaporator is cooled and thus loses part of its water vapor carrying capacity, the condensate mainly comprises water condensed in the evaporator. The collection tube 13 can also carry cold air. The presence of air is due to the recovery tube 13 starting near the evaporator where the air may be slightly pressurized by the blower of the air conditioning system.

  The recovery tube 13 may include a water tank 18 that can receive water from the evaporator 9. In the embodiment shown, the water tank 18 is arranged upstream of the condenser 5 and an overflow duct 190 is arranged from this water tank 18 towards a point downstream of the recovery pipe 13.

  In the condenser 5, the refrigerant is cooled by both ambient air and condensate. For this reason, the condensate is heated by the refrigerant in the condenser. This heating converts at least a portion of the condensed water into water vapor. This water vapor will eventually be mixed with the air carried by the recovery tube to form heated humidified air. The condensate heated in the condenser 5 is then conveyed to the vehicle compartment 2 by the return pipe 14 and humidifies the vehicle compartment 2. Thus, at the outlet of the condenser, the condensate may contain water vapor and / or humidified air and / or possibly some residual water.

  Next, with particular reference to FIG. 2, the passenger compartment 2 includes at least one air duct 15 with an opening 16 through which air flows into the passenger compartment 2. The air ducts preferably each have several pieces to selectively distribute ventilation to the passenger's feet, to the passenger's body and head, or to the windshield or other window surface. Fig. 2 is a part of a passenger compartment ventilation circuit including several ducts with openings. An air conditioner 17 coupled to the evaporator 9 is provided in the interior of the passenger compartment 2 or in the engine room, and sends cooled air into the air duct 15.

  The return pipe preferably delivers at least a portion of the heated condensate to the duct 15. In this duct, these heated condensates are mixed with the air coming into the passenger compartment. The return pipe sends the heated condensate to the duct so that the heated condensate is distributed to all openings 16. Preferably, however, the heated condensate is distributed in an opening that is directed toward the passenger's upper body rather than being distributed in an opening that is directed toward the windshield or other window. While preferably only the gaseous portion of the heated condensate is sent to the passenger compartment, residual water that may be present is preferably discarded either outside the vehicle or in the tank 18. Nevertheless, the remaining heated condensed water may also be atomized and introduced into the passenger compartment.

  Preferably, the air conditioning system 1 further comprises a humidity sensor 19 arranged in the passenger compartment 2 of the motor vehicle and means coupled to the humidity sensor 19 and for adjusting the flow of the heated condensate according to the measured humidity. And may include. This means includes a sensor 19, a first valve 21 disposed on the recovery pipe 13 between the water tank 18 and the condenser 5, and a condenser 5 and the air duct 15 on the return pipe 14. An electronic controller 20 may be included coupled to the second valve 22 disposed. As shown in this example, the second valve 22 is a three-way valve that directs the heated condensate to either the air duct 15 and / or to the atmosphere if humidification of the cabin air is not required. Good. As an alternative method, the sensor 19 may be a temperature and humidity sensor.

  The flow of condensate in the recovery pipe, in the heat exchanger and in the return pipe is brought about by some overpressure in the evaporator, gravity and / or the arrangement of pumps, for example arranged in the recovery pipe and / or return pipe. .

  Two embodiments of a condenser that can be used in an air conditioning system according to the present invention are described below.

  In one embodiment of the invention, the condenser 5 has an overall structure similar to the conventional condenser shown in FIGS. 3 and 4 and additional or alternative features described below.

  For this reason, the condenser 5 may have a substantially parallelepiped shape. The condenser includes a refrigerant inlet 25 and a refrigerant outlet 26 disposed proximate to the same vertical edge 27 of the condenser 5, and the outlet 26 is preferably disposed above the inlet 25.

  The condenser 5 may include a plurality of parallel conduits 29 extending from the refrigerant inlet 25 to the refrigerant outlet 26, which extend between the vertical edges 27, 28 of the condenser 5. Fins 30 can be provided between adjacent conduits 29 to increase condensation efficiency.

  Furthermore, side chambers may be arranged on each side of the conduit, preferably close to the corresponding vertical edges 27,28. As such, the first side chamber 31 is disposed proximate to the vertical edge 27 of the inlet 25 and outlet 26, and the second side chamber 32 is disposed proximate to the other vertical edge 28. The Chambers 31 and 32 are in fluid communication with conduit 29.

  The conduit 29 may be arranged as a continuous set of parallel conduits from the refrigerant inlet 25 to the refrigerant outlet 26. In the illustrated embodiment, the condenser 5 comprises three successive sets of conduits 29, namely a first set 33 at the top of the condenser 5, a second set 34 at the middle of the condenser 5, and the condenser 5. A lower third set 35. For example, the first set 33 may include nine conduits 29, the second set 34 may include seven conduits 29, and the third set 35 may include six conduits 29. Needless to say, these numbers are merely illustrative.

  The refrigerant flows in the same direction in the same set of conduits 29 but in the opposite direction in one set of conduits 29 and the next set of conduits 29. The first chamber 31 includes a partition wall 36 disposed substantially at the height of the boundary line 37 between the first set 33 and the second set 34, and the second chamber 32 is substantially A partition wall 38 disposed at the height of the boundary line 39 between the second set 34 and the third set 35 is included.

  In the example shown in FIGS. 3 and 4, the gaseous refrigerant stream enters the first side chamber 31 of the condenser 5 through the inlet 25 to the partition wall 36 and is divided by the first set 33 of conduits 29. Divided into streams. The refrigerant then enters the second side chamber 32 up to the partition wall 38 and flows through the second set 34 of conduits 29 in the opposite direction toward the first side chamber 31. Finally, the refrigerant flows through the third set 35 of conduits 29 toward the second side chamber 32. The refrigerant is collected by a return tube 40 that extends along the second side chamber 32 in a substantially vertical direction and then extends substantially horizontally toward the outlet 26.

  In the illustrated embodiment, the refrigerant is cooled and condensed in the condenser 5 using both ambient air and condensate as a means. In the first set 33 of conduits 29, the refrigerant is mostly gaseous, while in the third set 35 of conduits 29, the refrigerant is mostly liquid.

  5 to 8 relate to a first embodiment of a condenser 5 for an air conditioning system according to the present invention.

  According to this embodiment, the at least one conduit 29 has an inner flow path 41 through which condensate can flow, and an outer flow path through which the refrigerant can flow substantially coaxially with the inner flow path 41. 42. The inner and outer channels are separated by a continuous wall of material from which the conduit 29 is made, for example, a metal such as aluminum. Accordingly, the inner and outer channels are liquid tight with each other. Air circulates around the outer surface of the conduit.

  The outer flow path 42 extends in the axial direction and is arranged in a plurality of separate holes 43 disposed substantially entirely around the inner flow path 41 so that the conduit 29 can be easily manufactured as a single piece, for example by extrusion. May be formed. The conduit 29 may have a substantially circular cross section (FIG. 5) or a flat cross section (FIG. 6).

  Preferably, at least the last set, in this case the third set 35 of conduits 29, is made with an inner channel 41 and an outer channel 42, generally according to FIG. Actually, most of the refrigerant flowing in the conduits 29 of the third set 35 is liquid, so that the heat transfer coefficient between the refrigerant and the condensate becomes better, which helps to improve the condensation efficiency.

  As shown in FIGS. 7 and 8, the conduit 29 may be fabricated such that the inner channel 41 extends axially beyond the outer channels 42, 43 at each end. The conduit is connected to the side chamber so that the outer channels 42, 43 are fluidly connected to the corresponding side chamber. On the other hand, the inner flow path 41 extends through the side chamber entirely to the outside of the side chamber in a state where there is no fluid communication between the inner flow path and the corresponding side chamber. The inner channel 41 of one conduit 29 is substantially C-shaped at one end and is connected to one adjacent conduit 29 by a connecting tube 44 arranged outside the corresponding side chamber 31, 32. To the corresponding end of the inner flow path. At the opposite end (not shown), the inner channel 41 of the same conduit 29 is connected by another connecting tube 44 and to the corresponding end of the inner channel of one other adjacent conduit 29. Is done. Thus, the inner flow paths of adjacent conduits form a serpentine path along the set of conduits, and the condensate flows in one direction in one conduit 29 and in the opposite direction in the adjacent conduit. As a result, the condensate follows a serpentine path between the side chambers 31, 32.

  The condenser 5 of the first embodiment is very efficient because heat transfer between the refrigerant and the condensate is ensured along the entire length of the conduit 29.

  According to the second embodiment shown in FIG. 9, the condenser 5 further comprises an additional conduit 45 through which the condensate can flow, which additional conduit 45 is arranged in at least one of the side chambers 31, 32. The

  The additional conduit 45 may have a U shape that extends along the entire height of the side chambers 31, 32. This additional conduit preferably also includes an overflow duct 46. In the illustrated embodiment, it is designed to enhance heat transfer between the cap 47 at the upper end of the corresponding side chamber 31, 32 and the condensate flowing in the conduit 45 and the refrigerant flowing in the conduit 29. Fins 48 are provided.

  A significant advantage of this second embodiment is that it makes it possible to increase the condensation efficiency without costly modifying the structure of the condenser.

  Needless to say, the efficiency of the same condenser 5 can be further improved by combining the features of the first and second embodiments.

  According to the present invention, the humidity in the passenger compartment is adjusted by introducing the heated condensate so that passengers do not feel an undesirable moisture. The heat required for this method is “free” because it is otherwise dissipated into the ambient air, and this heat actually contributes to improving the efficiency of the air conditioner. Profit doubles.

  By providing a specific condenser as a three-fluid heat exchanger with higher efficiency, the present invention makes it possible to quickly adjust the operation of the compressor 4 and the fan 6. As a result, fuel consumption due to the operation of the compressor 4 and the fan 6 is reduced.

  In order to further increase the efficiency of the air conditioning system 1, the method according to the invention comprises the step of combining the flow of condensate in the condenser with the start of the fan, if necessary.

  Needless to say, the present invention is not limited to the embodiments described above as non-limiting examples, but conversely includes all the embodiments.

Claims (10)

An air conditioning system for an automobile compartment (2) comprising an air flow (10) directed towards a compressor (4), a condenser (5), an expander (8) and said compartment (2). In an air conditioning system comprising a refrigerant circuit (3) carrying refrigerant in a loop continuously passing through an evaporator (9) capable of cooling):
A collector (12) that collects the condensate that is found in the evaporator (9) during use, and enables thermal contact between the condensate and the refrigerant so that the refrigerant is cooled by the condensate. recovery tube heat exchanger designed so that the condensate is heated I than (5) and towards carrying the condensate (13),
Provided between the heat exchanger (5) and the casing (2), to humidify the casing (2), said vehicle at least a portion of the condensate that is heated by the heat exchanger air conditioning system comprising a luck department return pipe (14) into the chamber (2).   The air conditioning system according to claim 1, wherein the heat exchanger is integrated with the condenser (5).   The condenser (5) includes a plurality of parallel conduits (29) through which ambient air can circulate, at least one of the conduits (29) allowing the condensate to flow. An inner channel (41) and an outer channel (42) substantially coaxial with the inner channel (41), wherein the refrigerant flows through the outer channel (41, 42). The air conditioning system according to claim 2.   The outer flow path (42) is formed by a plurality of holes (43) extending substantially in the axial direction around the inner flow path (41) and allowing the refrigerant to flow. The air conditioning system according to claim 3, wherein the system is an air conditioning system.   The air conditioning system according to claim 3 or 4, characterized in that the conduit (29) has a substantially circular cross section or a flat cross section.   Includes parallel conduits (29) in a continuous set (33, 34, 35) through which ambient air can circulate, the refrigerant flowing in the same direction in the same set of conduits (29) And in a set of the conduits (29) and in a subsequent set of the conduits (29) in opposite directions, at least the conduits (29) of each of the last set (35) An inner channel (41) through which a liquid can flow; and an outer channel (42) substantially coaxial with the inner channel (41), wherein the refrigerant is the inner channel (41, 42). The air-conditioning system according to claim 3, wherein the air-conditioning system flows through the inside of the air-conditioning system.   The condenser (5) includes a plurality of parallel conduits (29) from a refrigerant inlet (25) to a refrigerant outlet (26), and side chambers (31, 31) disposed on each side of the conduit (29). 32), wherein the refrigerant can flow from one conduit to a subsequent conduit, and the condenser (5) further includes an additional conduit (45) through which the condensate can flow. The air conditioning system according to any of claims 2 to 6, characterized in that the additional conduit (45) is arranged in at least one side chamber (31, 32).   The air conditioning system according to any one of claims 1 to 6, wherein the recovery pipe (13) includes a water tank (18) capable of receiving water from the evaporator (9).   A humidity sensor (19) disposed in the passenger compartment (2) of the automobile and means coupled to the humidity sensor (19) and capable of adjusting the flow of heated condensate according to the measured humidity ( The air conditioning system according to any one of claims 1 to 8, further comprising: 20, 21, 22).   A motor vehicle having a passenger compartment (2), characterized in that it comprises an air conditioning system (1) according to any one of the preceding claims.

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