JP2004175269A - Air conditioner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To miniaturize an air conditioner. <P>SOLUTION: In the case of the maximum cooling operation, two heat exchangers 3, 4 are used as cooling heat exchangers for cooling both of the heat exchangers 3, 4 by air by supplying cold water to them. In the case of a temperature control mode, the first heat exchanger 3 only is used as the cooling heat exchanger. Thus, the maximum cooling ability is achieved by means of the two heat exchangers. Therefore, the heat exchanger can be miniaturized compared with the case that the maximum cooling ability is achieved by only one heat exchanger, and the air conditioner can be miniaturized. In addition, in the case of the temperature control mode, the cooling ability which can make dehumidification possible is enough, therefore, a lack of cooling ability hardly occurs in the case of the temperature control mode. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an air conditioner, and is effective when applied to a vehicle air conditioner.
[0002]
Problems to be solved by the prior art and the invention
Usually, an air conditioner for a vehicle has a heat exchanger exclusively for cooling for cooling air blown into a room and a heat exchanger exclusively for heating to heat air blown into a room. Between the cool air that passes through the cooling heat exchanger and bypasses the heating heat exchanger and the hot air that passes through the cooling heat exchanger and the heating heat exchanger. An air mix method is employed in which the temperature of air blown into a vehicle compartment is controlled by adjusting the air volume ratio.
[0003]
As another temperature control method, the entire amount of air that has passed through the cooling heat exchanger is passed through the heating heat exchanger, and the air that is blown into the vehicle interior by adjusting the heating capacity of the heating heat exchanger. There is a reheat method for controlling the temperature of the reheat.
[0004]
By the way, the capacity of the cooling only heat exchanger is determined by the cooling capacity required during the rapid cooling operation (cool down operation). Here, the rapid cooling operation is an operation in which the vehicle interior air that has been left under the summer sunshine for a long time and has reached 40 ° C. to 50 ° C. or more has been reduced to about 25 ° C. in a short time, so that cooling-only heat exchange is performed. Vessels require very large capacities.
[0005]
For this reason, the heat exchanger exclusively used for cooling becomes large, which has been a major obstacle in reducing the size of the vehicle air conditioner.
[0006]
In view of the above points, the present invention firstly aims at providing a new air conditioner different from the conventional one, and secondly, aims at miniaturization of the air conditioner.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, according to the first aspect of the present invention, an air-conditioning casing (1) through which air blown into a room flows, and air and heat stored in the air-conditioning casing (1) and blown into a room. At least two heat exchangers (3, 4) for exchanging heat with the medium, and a temperature lower than the temperature of the introduced air introduced into the air conditioning casing (1) to the two heat exchangers (3, 4). Full mode for supplying a heat medium at a higher temperature than the inlet air or a heat medium at a temperature higher than the inlet air to one of the two heat exchangers (3, 4) And a switching control unit for switching between a temperature control mode for supplying a heat medium having a lower temperature than the introduced air to the other heat exchanger.
[0008]
Thus, for example, during the maximum cooling operation, the two heat exchangers (3, 4) are made to function as cooling heat exchangers for air cooling. In the temperature control mode, for example, only the first heat exchanger (3) is used for cooling. It becomes possible to function as a heat exchanger.
[0009]
Therefore, for example, since the maximum cooling capacity is exhibited by the two heat exchangers, the size of the heat exchanger can be reduced as compared with the case where the maximum cooling capacity is exhibited by one heat exchanger, and the air conditioner Can be reduced in size.
[0010]
The invention according to claim 2 is characterized in that the heat medium supplied to the two heat exchangers (3, 4) is the same type of fluid.
[0011]
According to a third aspect of the present invention, the heat medium supplied to the two heat exchangers (3, 4) is water.
[0012]
According to the fourth aspect of the present invention, the heat medium having a temperature lower than that of the introduced air evaporates the refrigerant by utilizing the effect of the adsorbent adsorbing the gas-phase refrigerant, and exhibits a refrigerating ability by the latent heat of evaporation. Machine.
[0013]
According to a fifth aspect of the present invention, there is provided a vehicle air conditioner including the air conditioner according to any one of the first to third aspects, wherein the heat medium having a higher temperature than the introduced air is generated in the vehicle. It is characterized by being generated by waste heat.
[0014]
Thereby, as described in claim 1, the size of the air conditioner can be reduced.
[0015]
Incidentally, reference numerals in parentheses of the above-mentioned units are examples showing the correspondence with specific units described in the embodiments described later.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
(1st Embodiment)
In the present embodiment, the air conditioner according to the present invention is applied to a vehicle air conditioner, and FIGS. 1 and 2 are schematic diagrams of the air conditioner (air conditioner unit) according to the present embodiment.
[0017]
In FIG. 1, an air-conditioning casing 1 is a duct means through which air blown into a room flows, and a centrifugal blower 2 for sucking air from a room or outside and blowing air into the room is provided at the most upstream side of the air flow. Is provided.
[0018]
In this embodiment, the air-conditioning casing 1 (air-conditioning unit) is mounted under the vehicle floor or under the seat.
[0019]
In addition, the most downstream side of the airflow of the air-conditioning casing 1 is a face outlet that blows air toward the upper body of the occupant, a foot outlet that blows air toward the lower body of the occupant, and blows air toward the window glass. A blow mode switching device is provided which communicates with a defroster blow port and the like, and switches a blow mode, that is, a blow port for blowing air.
[0020]
In the air-conditioning casing 1, a first and second heat exchangers 3 that exchange heat between the air blown into the room and the heat medium are provided on the downstream side of the air flow from the blower 2 and on the upstream side of the blowout mode switching device. , 4 are housed, and the first heat exchanger 3 housed on the upstream side of the air flow is a heat exchanger dedicated to cooling the air blown into the room, and the second heat exchanger 3 housed on the downstream side of the air flow. The heat exchanger 4 is a heat exchanger that cools or heats air blown into a room.
[0021]
When cooling the air blown into the room, the heat medium generated (cooled) by the adsorption refrigerator is supplied to the second heat exchanger 4 and the first heat exchanger 3. Note that the adsorption refrigerator is a device that evaporates a refrigerant by using an adsorbent to adsorb a gas-phase refrigerant and exerts a refrigerating ability by latent heat of evaporation, and will be described in detail later.
[0022]
Here, the heat medium is water (including one in which an antifreeze such as ethylene glycol is mixed), and is the same fluid as engine cooling water that cools an engine (internal combustion engine) serving as a driving source for traveling. When the air blown into the room is heated by the second heat exchanger 4, the engine cooling water, that is, the heat medium overheated by the engine is supplied to the second heat exchanger 4.
[0023]
The air mix door 5 is an air volume ratio adjusting unit that adjusts the amount of air that passes through the second heat exchanger 4 among the air that has passed through the first heat exchanger 3, and the cool air bypass door 6 is provided with a first heat exchanger Door means for opening / closing a cold air bypass passage 6a which bypasses 3 to flow air to the second heat exchanger 4 side.
[0024]
Next, the adsorption refrigerator 10 will be described with reference to FIG.
[0025]
The adsorbent adsorbs refrigerant (water in the present embodiment) in an amount corresponding to the relative humidity of the adsorbent, that is, the relative humidity of the adsorbent surface. For this reason, when the adsorbent is heated, the relative humidity decreases, so that the adsorbed refrigerant is desorbed and released, and the relative humidity for cooling increases, so that the refrigerant in the atmosphere is adsorbed.
[0026]
When the adsorbent adsorbs the refrigerant (water vapor), heat of adsorption corresponding to the heat of condensation is generated. Therefore, in order to maintain the adsorbent's adsorption ability, it is necessary to adsorb the refrigerant while cooling the adsorbent. is there.
[0027]
Incidentally, in this embodiment, silica gel is used as the adsorbent, but it goes without saying that activated alumina, activated carbon, zeolite, molecular sieving carbon, or the like may be used.
[0028]
The outdoor heat exchanger 11 is a heat exchanger that exchanges heat between the heat medium circulating in the adsorber 12 and the outdoor air, and is generated in a vehicle such as an engine when the adsorbed refrigerant is desorbed and released. Heat (in the present embodiment, engine cooling water) is circulated in the adsorber 12. The switching valves V1 to V4 switch the circulation path of the heat medium.
[0029]
In addition, the adsorber 12 has a casing 12a made of stainless steel (SUS304 in this embodiment) in which a refrigerant (water in this embodiment) is sealed while the inside is kept substantially in a vacuum, and a heat medium and the casing 12a. And a second heat exchanger 12c serving as an adsorption core that cools or heats the adsorbent, and the like.
[0030]
A low-temperature (for example, about 5 ° C.) heat medium generated by the adsorption refrigerator is supplied to the second heat exchanger 4, and a high-temperature (for example, 90 ° C.) heated by the engine is used. Switching with the case where the heat medium is supplied to the second heat exchanger 4 is performed by the switching valve V5.
[0031]
Next, the general operation of the adsorption refrigerator 10 will be described. In addition, in order to facilitate the following description, the first heat exchanger 3 and the second heat exchanger 4 are collectively referred to as indoor heat exchangers 3 and 4.
[0032]
First, the switching valves V1 to V4 are operated as shown by the solid lines in FIG. 3, and between the first heat exchanger 12 b of the first adsorber 12 and the indoor heat exchangers 3 and 4, Between the second heat exchanger 12c and the outdoor heat exchanger 11, between the first heat exchanger of the second adsorber 12 and the outdoor heat exchanger 11, the second heat exchanger 12c of the second adsorber 12 Circulate the heat medium between the engine and the engine.
[0033]
As a result, the first adsorber 12 is in the adsorption step and the second adsorber 12 is in the desorption step, so that the air discharged into the room is cooled by the refrigerating capacity generated in the first adsorber 12, and the second adsorber 12 is cooled. The regeneration of the adsorbent is performed.
[0034]
That is, in this state (hereinafter, referred to as a first state), the first heat exchanger 12b of the first adsorber 12 functions as an evaporator that evaporates the liquid-phase refrigerant to generate a refrigerating capacity, and performs the first adsorption. The second heat exchanger 12c of the heat exchanger 12 functions as a cooler for cooling the adsorbent, the first heat exchanger 12b of the second adsorber 12 functions as a condenser for cooling water vapor desorbed from the adsorbent, The second heat exchanger 12c of the second adsorber 12 functions as a heater for heating the adsorbent.
[0035]
When a predetermined time (60 seconds to 100 seconds in the present embodiment) elapses in the first state, the switching valves V1 to V4 are operated as shown by the broken lines in FIG. Between the first heat exchanger 12b and the indoor heat exchangers 3 and 4, between the second heat exchanger 12c of the second adsorber 12 and the outdoor heat exchanger 11, and the first heat of the first adsorber 12 The heat medium is circulated between the exchanger and the outdoor heat exchanger 11, and between the second heat exchanger 12c of the first adsorber 12 and the engine.
[0036]
As a result, the second adsorber 12 is in the adsorption step, and the first adsorber 12 is in the desorption step, so that the air blown into the room is cooled by the refrigerating capacity generated in the second adsorber 12, and the first adsorber 12 is cooled. The regeneration of the adsorbent is performed.
[0037]
That is, in this state (hereinafter, referred to as a second state), the first heat exchanger 12b of the second adsorber 12 functions as an evaporator that evaporates the liquid-phase refrigerant to generate a refrigerating ability, and The second heat exchanger 12c of the heat exchanger 12 functions as a cooler for cooling the adsorbent, the first heat exchanger 12b of the first adsorber 12 functions as a condenser for cooling water vapor desorbed from the adsorbent, The second heat exchanger 12c of the first adsorber 12 functions as a heater for heating the adsorbent.
[0038]
Then, when a predetermined time has elapsed in the second state, the switching valves V1 to V4 are operated to return to the first state. Thus, the first state and the second state are alternately repeated at predetermined time intervals, and the air conditioner is continuously operated.
[0039]
The predetermined time is appropriately selected based on the remaining amount of the liquid refrigerant present in the casing 12a, the adsorbing capacity of the adsorbent, and the like.
[0040]
Next, the characteristic operation of the air conditioner according to the present embodiment will be described.
[0041]
1. Maximum cooling operation (full mode)
When the target outlet temperature TAO becomes lower than a predetermined value, or when the occupant manually selects the maximum cooling operation, the first and second heat exchangers 3 and 4 have a low temperature generated by the adsorption refrigerator. In addition to supplying the heat medium, as shown in FIG. 4, the cool air bypass door 6 is opened to supply the second heat exchanger 4 with air that has not passed through the first heat exchanger 3, and the first and second heat exchanges are performed. The air blown into the room is cooled by both the units 3 and 4.
[0042]
In the present embodiment, the air mixing door 5 is at the opening position such that the air that has passed through the first heat exchanger 3 does not pass through the second heat exchanger 4. Since the temperatures of the heat medium supplied to the first and second heat exchangers 3 and 4 are substantially the same, the opening position is set so that the air that has passed through the first heat exchanger 3 passes through the second heat exchanger 4. Is also good.
[0043]
Incidentally, the target outlet temperature TAO constitutes a control parameter determined based on a desired indoor temperature, an indoor temperature, and the like set by an occupant, and it is considered that a larger cooling capacity is required as the target outlet temperature TAO decreases. Conversely, it is considered that a larger heating capacity is required as the target outlet temperature TAO increases.
[0044]
Then, in the present embodiment, operation modes such as a maximum cooling operation (cool down) and a temperature control operation, an opening degree of the air mix door 5 and a blowing mode are automatically controlled based on the target blowing temperature TAO.
[0045]
2. Temperature control mode When the target outlet temperature TAO exceeds a predetermined value, or when the occupant manually raises the desired indoor temperature, as shown in FIG. A low-temperature heat medium generated by the heat exchanger is supplied, a heat medium heated by the engine is supplied to the second heat exchanger 4, and the air mix door 5 is opened with the cold air bypass door 6 closed. Degree, that is, the amount of air flowing through the second heat exchanger 4 after passing through the first heat exchanger 3 is adjusted so that the temperature of the air actually blown out in the vehicle compartment approaches the target blowout temperature TAO.
[0046]
Next, the operation and effect of the present embodiment will be described.
[0047]
As described above, in the present embodiment, during the maximum cooling operation, both of the two heat exchangers 3 and 4 function as cooling heat exchangers for air cooling, and only the first heat exchanger 3 during the temperature control mode. Functions as a heat exchanger.
[0048]
Therefore, since the maximum cooling capacity is exhibited by the two heat exchangers, the heat exchanger can be downsized compared to the case where the maximum cooling capacity is exhibited by one heat exchanger, and the air conditioner can be used. The size can be reduced.
[0049]
In the temperature control mode, it is sufficient that the cooling capacity is sufficient to be able to dehumidify, so that the cooling capacity is scarcely insufficient in the temperature control mode.
[0050]
Further, the same heat medium is supplied to the heat medium supplied to the second heat exchanger 4 irrespective of the time of cooling and the time of heating, so that the temperature generated by the adsorption refrigerator is low (for example, about The case where the heat medium is supplied to the second heat exchanger 4 and the case where the heat medium having a high temperature (for example, 90 ° C.) heated by the engine is supplied to the second heat exchanger 4 are easily performed. Switching can be performed, so that the structure of the air conditioner can be simplified and the manufacturing cost can be reduced.
[0051]
(2nd Embodiment)
In the first embodiment, the present invention is applied to an air mix method, but in the present embodiment, as shown in FIG. 6, the present invention is applied to a reheat method.
[0052]
In the present embodiment, in the temperature control mode, the amount of hot water supplied to the second heat exchanger 4 is adjusted by the flow control valve. In addition, the size of the air conditioner is further reduced by making the outer dimensions of the heat exchangers 3 and 4 in the direction of air flow smaller than that of the first embodiment to make them ultra-thin.
[0053]
(Other embodiments)
In the above embodiment, the cooling water for cooling is generated by the adsorption refrigerator, but the present invention is not limited to this. For example, the cooling water may be generated by a vapor compression refrigerator.
[0054]
When the cooling capacity is generated by the vapor compression refrigerator, a refrigerant such as Freon may be circulated directly to the first and second heat exchangers 3 and 4. In this case, in the temperature control mode, it is desirable to supply the high-pressure refrigerant of the vapor compression refrigerator to the second heat exchanger 4 to heat the air.
[0055]
In the above-described embodiment, the engine cooling water is used as the waste heat generated in the vehicle. However, the present invention is not limited to this. For example, in an electric vehicle such as a fuel cell vehicle, a fuel cell or an electric motor is used. The air blown into the room may be heated by the waste heat generated from the air, or the adsorption refrigerator may be operated.
[0056]
During the maximum heating operation (full mode), hot water may be supplied to both heat exchangers 3 and 4.
[0057]
Further, in the above-described embodiment, the air-conditioning casing 1 is mounted under the floor or the like. However, the present invention is not limited to this, and it goes without saying that the air-conditioning casing 1 may be mounted in a trunk room or below the instrument panel.
[Brief description of the drawings]
FIG. 1 is a schematic diagram of an air conditioner (air conditioning unit) according to a first embodiment of the present invention.
FIG. 2 is a schematic diagram of an air conditioner (air conditioning unit) according to the first embodiment of the present invention.
FIG. 3 is a schematic diagram of the adsorption refrigerator according to the first embodiment of the present invention.
FIG. 4 is an operation explanatory view of the air conditioner according to the first embodiment of the present invention.
FIG. 5 is an operation explanatory view of the air conditioner according to the first embodiment of the present invention.
FIG. 6 is a schematic diagram of an air conditioner (air conditioning unit) according to a second embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Air-conditioning casing, 2 ... Blower, 3 ... 1st heat exchanger, 4 ... 2nd heat exchanger,
5 ... Air mix door, 6 ... Cool air bypass door.

Claims (5)

An air-conditioning casing (1) through which air blown into the room flows,
At least two heat exchangers (3, 4) housed in the air conditioning casing (1) and exchanging heat between air and a heat medium blown into the room;
A full mode in which the two heat exchangers (3, 4) are supplied with a heat medium at a temperature lower than the temperature of the introduced air introduced into the air-conditioning casing (1) or a heat medium at a temperature higher than the introduced air; A heat medium having a higher temperature than the introduced air is supplied to one of the two heat exchangers (3, 4), and a heat medium having a lower temperature than the introduced air is supplied to the other heat exchanger. An air conditioner comprising: switching control means for switching between a temperature control mode for supplying a medium and a temperature control mode. The air conditioner according to claim 1, wherein the heat medium supplied to the two heat exchangers (3, 4) is the same type of fluid. The air conditioner according to claim 1, wherein the heat medium supplied to the two heat exchangers (3, 4) is water. The heat medium having a temperature lower than that of the introduced air is generated by an adsorption refrigerator in which an adsorbent evaporates a refrigerant by using an action of adsorbing a gas-phase refrigerant and exerts a refrigerating ability by latent heat of evaporation. The air conditioner according to any one of claims 1 to 3, wherein A vehicle air conditioner comprising the air conditioner according to any one of claims 1 to 3,
The heating medium having a higher temperature than the introduced air is generated by waste heat generated in a vehicle.

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