1. Field of the Invention
This invention relates to a cooling apparatus for cooling an object to be cooled such as an electronic device mounted on a vehicle in combination with an automotive climate control system, or in particular to a cooling apparatus using brine as a heat transfer medium.
2. Description of the Related Art
The evaporator of an automotive climate control system exchanges heat between refrigerant flowing in the evaporator and air in the passenger compartment. A cooling apparatus for cooling an on-vehicle object using this evaporator is known as disclosed in Japanese Unexamined Patent Publication No. 2001-1753. Japanese Unexamined Patent Publication No. 2001-1753 describes an air conditioning system having a cooling storage cycle for cooling a cool storage medium to supply cool air even when the vehicle engine is stopped. This cooling storage cycle uses brine as a heat transfer medium, and evaporator tubes are integrated as a double tube, in which the refrigerant flows in the inner tube while brine flows in the outer tube, so that the brine is cooled thereby cooling the cooling storage medium making up the object to be cooled.
The brine in the cooling storage cycle described above cools the cooling storage medium satisfactorily. The brine flowing in the outer tube of the double tube, however, constitutes a thermal resistance against heat exchange between the refrigerant and air in the passenger compartment, with the result that the quick-acting characteristic of the cooling operation of the climate control system may be deteriorated. Also, the process of integrally forming a double tube is complicated, and an evaporator having such a double tube is specially structured and expensive.
This invention has been achieved to solve the aforementioned problem of the prior art and the object thereof is to provide a cooling apparatus for cooling the object to be cooled such as an on-vehicle electronic device in combination with an automotive climate control system without deteriorating the quick-acting cooling characteristic of the automotive climate control system.
In order to achieve the object described above, the present invention employs the technical means described below.
According to this invention, there is provided a cooling apparatus for cooling an object to be cooled (100) mounted on the vehicle in combination with an automotive climate control system (10) having a refrigeration cycle for compressing and expanding a first heating medium,
The heat dissipator of the cooling apparatus, which is coupled to the tank unit of the evaporator of the climate control system, has no adverse effect on heat exchange between the first heating medium (refrigerant) flowing inside the tubes and air blowing between the tubes and fins of the evaporator, and therefore, the quick-acting cooling characteristic of the climate control system is not deteriorated. Also, even in the case where the climate control system is not being operated with no refrigerant flowing in the evaporator, heat can be normally radiated using an evaporator formed of aluminum as a heat radiator having a large surface area.
According to this invention, the second heating medium in liquid form is brine having a solidification point of lower than 0° C., and therefore, can be prevented from being frozen even in a cold environment.
According to this invention, the heat dissipator (40) is configured independently of the evaporator (15) and coupled to by being mounted on the tank unit (15c) of the evaporator. With this configuration, the evaporator used for the cooling apparatus according to the invention can be realized with a minor design change or without any design change of the existing evaporator.
According to this invention, the cooling apparatus may comprise a plurality of heat dissipators (40), the evaporator (15) may include a plurality of tank units (15b, 15c) connected to the each end of the tubes, and the plurality of the heat dissipators (40) are coupled to the plurality of the tank units (15b, 15c). As a result, a more uniform temperature distribution of the core unit of the evaporator is obtained and the cooling capacity of the cooling apparatus is improved.
According to this invention, the cooling apparatus may further comprise a temperature sensor (70) for detecting the temperature (Tb) of the second heating medium, and a control unit (80) for activating the blower (16) of the climate control system (10) when the temperature (Tb) detected by the temperature sensor (70) reaches a predetermined temperature (T1).
With this configuration, even in the case where the climate control system is not being operated and no refrigerant is flowing in the evaporator, heat transmitted to the evaporator from the heat dissipators of the cooling apparatus can be efficiently radiated by applying the air of the blower to the evaporator.
According to this invention, the climate control system (10) includes an air blowing unit case (17) having a heat discharge outlet port (25) for accommodating the evaporator (15) and the blower (16) and adapted to be opened or closed, and the control unit (80) controls the heat discharge outlet port (25) to open upon activation of the blower (16). As a result, even in the case where the climate control system is not being operated and the cool air outlet of the air blowing unit case is closed, the blower can be activated of the cooling apparatus.
According to this invention, the control unit (80) controls the pump (50) to reduce the flow rate of the second heating medium in liquid form when the temperature (Tb) detected by the temperature sensor (70) drops to or below a predetermined temperature (T3). As a result, condensation or the like, which otherwise might be caused by excessively cooling the electronic device can be prevented.
According to this invention, the cooling apparatus further comprises a flow rate control valve, and the control unit (80) controls the flow rate control valve in place of the pump (50). As a result, condensation or the like, which otherwise might be caused by excessively cooling the electronic device can be prevented.
According to this invention, the cooling apparatus may further comprise a second temperature sensor (72) for detecting the temperature (Tk) of the heat absorber (30), wherein the tubular path (60) for circulating the second heating medium in liquid form includes a tubular bypass (61) for circumventing the heat absorber (30) and a switching valve (62) arranged at a diverging point of the tubular bypass (61), and wherein the control unit (80) activates the switching valve (62) in such a manner that the second heating medium in liquid form circumvents the heat absorber (30) and flows through the tubular bypass (61) when the temperature (Tb) detected by the temperature sensor (70) drops to or below a predetermined temperature (T3) and the second heating medium flows through the heat absorber (30) when the temperature (Tk) detected by the second temperature sensor (72) rises to or above another predetermined temperature (T5). As a result, condensation or the like, which otherwise might be caused by excessive cooling of the electronic device can be also prevented.
According to this invention, the cooling apparatus may further comprise a temperature sensor (70) for detecting the temperature (Tb) of the second heating medium and a control unit (80) for activating the blower (16) of the climate control system (10) when the temperature (Tb) detected by the temperature sensor (70) reaches a predetermined temperature (T1), wherein the climate control system (10) includes an air blowing unit case (17) for accommodating the evaporator (15) and the blower (16) and having a heat discharge outlet (25) adapted to open/close, wherein the air blowing unit case (17) includes an external air inlet (19), an internal air inlet (18) and an internal/external air switching door (20) for opening/closing the external air inlet (19) and the internal air inlet (18), wherein in the case where the temperature (Tb) detected by the temperature sensor (70) while the vehicle is running at a predetermined speed or higher reaches a predetermined temperature (T1), the control unit (80) controls the operation of the internal/external air switching door (20) to introduce air from the external air inlet (19) while at the same time opening the heat discharge outlet port (25). As a result, the heat from the heat dissipator of the cooling apparatus can be radiated by cooling the evaporator with air flow caused by driving the vehicle without activating the blower.
Incidentally, the reference numeral in each parenthesis attached to each name of the means described above shows an example of correspondence with the specific means described in the embodiments below.
The present invention may be more fully understood from the description of preferred embodiments of the invention, as set forth below, together with the accompanying drawings.
With reference to the accompanying drawings, a preferred first embodiment of the invention will be explained in detail. The cooling apparatus 1 according to the first embodiment is for cooling an electronic device mounted on a vehicle and configured to radiate heat generated in the electronic device to the evaporator of an automotive climate control system.
The evaporator 15 according to this embodiment is of an ordinary type called a “drone cup” used for the automotive climate control system, and therefore, only a general structure thereof is shown in
In the cooling apparatus 1 according to the first embodiment, as shown in
The heat dissipator, as designated by reference numeral 40 in
The heat absorber 30, though not shown in detail, like the aforementioned heat dissipator 40, includes a heat absorber case formed of aluminum substantially in the shape of a parallelepipedal box, and a brine inlet port and a brine outlet port arranged on the opposed side surfaces of the case. The brine is filled and flows in the space formed in the case. The heat absorber case has one side surface thereof fixed in contact with the high-temperature parts of the electronic device 100 with a band or the like to receive heat therefrom. For this purpose, fixing means such as a screw may be used in accordance with the structure of the electronic device 100 to be cooled, or depending on the cooling conditions, the heat absorber unit case may be placed in a casing of the electronic device, surrounded by high-temperature air but not in contact with any heat-generating parts thereof.
The operation of the cooling apparatus 1 according to this embodiment will now be explained. The heat generated in the electronic device 100 is transmitted to the brine through the heat absorber 30, and the brine is sent to the heat dissipator 40 by the pump 50. The heat contained in the brine is transmitted to the low-temperature refrigerant in the lower tank unit 15c of the evaporator through one side of the heat dissipator case 41 and the bottom of the lower tank unit 15c thereby to cool the electronic device 100.
The heat transmission explained above concerns a case in which the compressor 11 of the climate control system 10 is activated and the low-temperature refrigerant flows in the evaporator 15. Nevertheless, the cooling apparatus 1 according to the invention can cool the electronic device 100 even when the compressor 11 of the climate control system is not being operated. Specifically, in a case where the compressor 11 is not in operation, the temperature of the evaporator 15 is substantially equal to ambient air temperature. However, since the electronic device 100 generates heat, the temperature thereof is higher than ambient air temperature, as well as the temperature of the brine for transmitting the heat of the electronic device 100. Thus, heat contained in the brine of the heat dissipator 40, after being transmitted to the metal case forming the lower tank unit 15c of the evaporator and the tubes and fins of the evaporator, is dissipated into ambient air thereby to cool the electronic device 100. The core unit of the evaporator has a large surface area, and therefore, the evaporator, even if no refrigerant flows therein, can be used as a heat radiator. Also, heat transmitted from the brine to the evaporator 15 is not only radiated from the evaporator 15 by the natural cooling function of air, but also can be radiated efficiently by being forcibly cooled by air blown from the blower 16 to the evaporator 15. As another alternative, without activating the blower 16, heat can be radiated forcibly by atmospheric air introduced and blown to the evaporator 15 while the vehicle is moving.
The heat dissipator of the cooling apparatus according to the first embodiment described above is mounted on and coupled to the lower tank unit of the evaporator. Alternatively, the heat dissipator case and the lower tank unit of the evaporator may be formed integrally with each other. In such a case, contact heat resistance which otherwise might be generated between the independent heat dissipator 40 and the lower tank unit according to the first embodiment is eliminated, and therefore heat conductivity is improved.
A cooling apparatus 2 according to a second embodiment will not be explained with reference to
A cooling apparatus 3 according to a third embodiment will now be explained with reference to
The control unit 80 activates the blower 16 in the air blowing unit case 17 in accordance with temperature detected by the temperature sensor 70 while the compressor is not being operated. Specifically, in a case where the brine temperature Tb rises to a predetermined temperature T1 or higher, the blower 16 is activated to forcibly cool the evaporator 15 by air, however when the detected temperature Tb drops to a predetermined temperature T2 lower than the predetermined temperature T1, the blower 16 is stopped. Also, the control unit 80 activates an electric motor (not shown) for opening the door 28 on the heat discharge outlet 25 at the same time as the blower 16. In order to reduce the failure rate of the blower motor 16a, the r.p.m. of the blower 16 may be increased or decreased without starting/stopping the blower 16 as described above. Also, the brine temperature may be measured at other points than the aforementioned points. For example, the temperature of the brine in the heat absorber 30 or the heat dissipator 40 may be measured, or the temperature of the case of the heat absorber or the heat dissipator may be measured as the brine temperature. As another alternative, the temperature of the electronic device 100 may be measured by a temperature sensor.
A cooling apparatus 4 according to a fourth embodiment will now be explained with reference to
A control flowchart of the cooling apparatus according to the fourth embodiment is shown in
Instead of controlling the flow rate of the circulating brine by controlling the output of the pump 50 as in the cooling apparatus 4 according to the fourth embodiment, a flow rate control valve may be arranged in the brine circulating path, and the flow rate may be controlled by the control unit 80 adjusting the valve opening degree of the flow rate control valve.
A cooling apparatus 5 according to a fifth embodiment will now be explained with reference to the schematic diagram of
A cooling apparatus 6 according to a sixth embodiment will now be explained with reference to
While the invention has been described by reference to specific embodiments chosen for purposes of illustration, it should be apparent that numerous modifications could be made thereto by those skilled in the art without departing from the basic concept and scope of the invention.
Number | Date | Country | Kind |
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2006-227105 | Aug 2006 | JP | national |