GB2179137A

GB2179137A - Air conditioners for vehicles

Info

Publication number: GB2179137A
Application number: GB08618353A
Authority: GB
Inventors: Tetsuro Furukawa; Kensuke Yoshikawa; Mitsuru Mizuuchi; Masaharu Furutera; Nobuharu Sakabata; Tomoyoshi Muto; Yoshiaki Matsushita; Kingo Hayashi; Nobuji Shibamoto
Original assignee: Hitachi Zosen Corp
Current assignee: Hitachi Zosen Corp
Priority date: 1985-08-01
Filing date: 1986-07-28
Publication date: 1987-02-25
Anticipated expiration: 2006-07-28
Also published as: GB2194624B; GB2179137B; DE3625707A1; GB8618353D0; GB8718753D0; GB2194624A; KR870001961A

Abstract

The air conditioner comprises an evaporator 5 for evaporating a refrigerant liquid to cool the air in a car interior 4, an absorbing unit 3 in which refrigerant vapor from the evaporator 5 is absorbed by an absorbent liquid, a regenerator 7 in which a low concentration absorbent liquid which has absorbed refrigerant liquid in the absorbing unit 3 is heated by the heat of an engine cooling liquid to evaporate the refrigerant, a condenser 2 for cooling refrigerant vapor from the regenerator 7 to condense the refrigerant vapor, a first refrigerant line 13 for introducing refrigerant vapor from the evaporator 5 into the absorbing unit 3, a first absorbent liquid line 15 for introducing the low concentration absorbent liquid from the absorbing unit 3 into the regenerator 7, a second refrigerant line 10 for introducing refrigerant vapor from the regenerator into the condensing unit 2, a third refrigerant line 12 for introducing the refrigerant liquid from the condensing unit 2 into the evaporator 5, a second absorbent liquid line 17 for introducing a high concentration absorbent liquid from the regenerator 7 into the absorbing unit 3, a heater 8 for heating the air in the car interior 4, and circulating lines 18 and 19 for circulating the engine cooling liquid through the heating 8 and the regenerator 7. <IMAGE>

Description

SPECIFICATION Air conditioner for Vehicles The present invention relates to an air conditioner for vehicles using an absorption type heat pump.

In the heating and cooling of automobiles, the heat retained by engine cooling water is utilized for heating, while, for cooling, part of the engine power is used for driving the compressor for condensing vaporized refrigerant.

More particularly, a refrigerant liquid line and a refrigerant vapor line are installed between an evaporator for cooling car interior air and a refrigerant condenser cooled by an engine cooling fan, and a compressor for compressing the refrigerant is placed somewhere between the ends of said refrigerant vapor line, said compressor being driven by the engine, the engine cooling water being circulated through a heater for heating car interior air.

According to the conventional air conditioner described above, since driving power for the compressor is derived from the engine, the fuel consumption rate of the engine greatly increases during cooling, and since increased power is required for acceleration, there is a problem that acceleration performance is considerably degraded.

The present invention has for its object the provision of an air conditioner for vehicles which does not increase the fuel consumption rate of the engine and does not adversely affect the acceleration performance of the car.

According to a first aspect of the invention.

there is provided an air conditioner for vehicles comprising evaporating means for evaporating a refrigerant liquid to cool car interior air, absorbing means in which refrigerant vapor from said evaporating means is absorbed by an absorbent liquid, regenerating means in which a low concentration absorbent liquid which has absorbed refrigerant in said absorbing means is heated by the heat of an engine cooling liquid to evaporate the refrigerant, condensing means for cooling refrigerant vapor from said regenerating means to condense said refrigerant vapor, a first refrigerant line for introducing refrigerant vapor from said evaporating means into said absorbing means, a first absorbent liquid line for introducing the low concentration absorbent liquid from said absorbing means into said regenerating means, a second refrigerant line for introducing refrigerant vapor from said regenerating means into said condensing means, a third refrigerant line for introducing the refrigerant liquid from said condensing means into said evaporating means, a second absorbent liquid line for introducing a high concentration absorbent liquid from said regenerating means into said absorbing means, heating means for heating car interior air, a circulating line for circulating the engine cooling liquid through said heating means and said regenerating means, a first ventilating line for introducing air cooled by said evaporating means directly into the car interior, a second ventilating line for introducing said air into the car interior through said heating means, and switching means for selectively switching between said first and second ventilating lines.

According to the arrangemtnt described above, the rotative driving power of the engine is not directly utilized but the heat from the engine is utilized to air-condition the car interior; thus, an increase in fuel consumption rate is avoided and there is no danger of adversely affecting the acceleration performance of the vehicle.

A preferred embodiment using the aforesaid arrangement includes, besides said absorbing means and said condensing means, intermediate absorbing means and intermediate condensing means, thereby providing a 2-stage absorbing type heat cycle, which ensures that sufficient cooling function is developed even if the engine cooling liquid is ordinary cooling water (boiling point: 100 C).

According to a second aspect of the present invention, there is provided an air conditioner for vehicles wherein an absorbing type cooling device having evaporating means, absorbing means and regenerating means is mounted on a vehicle, said evaporating means being separated from the cooling device body and serving as heat exchange means for cooling the car interior, said cooling device body comprising first plate bodies each having at least formed therein an absorbing compartment and a regenerating compartment, and second plate bodies each having formed therein cooling and heating water passages for cooling and heating said compartments, respectively, said first and second plate bodies being united through heat transfer plates into laminate form, the arrangement being such that the heat from said absorbing compartment and said condensing means is radiated through heat radiating means installed forwardly of an engine cooling water radiator and hot water in the engine cooling water radiator is introduced into the regenerating compartment heating water passage.

According to the arrangement described above, since the absorbing type cooling device is used as a cooling device for vehicles and hot water in the radiator is utilized as a drive heat source, fuel consumption rate is reduced as compared with the conventional type in which the compressor is driven directly by the engine. Further, since the body of the cooling device is united into laminate form, the device is compact and convenient to mount on an automobile. And the device is rugged, so that it is suitable for being mounted on an automobile, which produces vibration.

Fig. 1 is a schematic block diagram of an air conditioner according to a first embodiment of the invention; Figs. 2(b) and 2(b) are schematic principal block diagrams showing modifications of a circulation passage for engine cooling liquid; Fig. 3 is a schematic block diagram of an air conditioner according to a second embodiment of the invention; Fig. 4 is a schematic block diagram of an air conditioner according to a fourth embodiment of the invention; Fig. 5 is a graph showing the relationship between temperature and pressure concerning R 22-DMF type refrigerant liquid; Fig. 6 is a Dühring diagram showing the relationship between temperature and pressure concerning CH3OH-LiBr type refrigerant liquid; Fig. 7 is a schematic block diagram of an air conditioner according to a fourth embodiment of the invention;; Fig. 8 is a schematic principal block diagram showing a modification of a circulation passage for engine cooling liquid in the fourth embodiment of the invention; Fig. 9 is a schematic block diagram of an air conditioner according to a fifth embodiment of the invention; Fig. 10 is a schematic block diagram of an air conditioner according to a sixth embodiment of the invention; Fig. 11 is a schematic block diagram of an air conditioner according to a seventh embodiment of the invention; Fig. 12 is a During diagram showing the relationship between temperature and pressure concerning R 22-DMF type refrigerant-absorbent liquid in the sixth embodiment; Fig. 13 is a Dühring diagram showing the relationship between temperature and pressure concerning H20-LiBr type refrigerant-absorbent liquid in the sixth embodiment;; Fig. 14 is a schematic block diagram of another air conditioner according to the first embodiment of the invention; and Fig. 15 is a schematic block diagram of another air conditioner according to the second embodiment of the invention.

A first embodiment of an air conditioner for vehicles according to the invention will now be described with reference to drawings.

In Fig. 1, mounted on a vehicle 1 are a condenser (condensing means) 2 for radiating heat of condensation by heat exchange with the open air, an absorbing unit (absorbing means) 3 for removing absorbed heat, an evaporator (evaporating means) 5 for evaporating refrigerant liquid to cool the air in a car interior 4, a refrigerant and absorbent liquid regenerator (regenerating means) 7 for utilizing the heat of the engine cooling liquid which passes through the jacket 6 of an engine and cools the engine 6, a heater (heating means) for heating the air in the car interior 4, and a heat recovery unit 8. A refrigerant vapor line (second refrigerant line) 10 is installed between a gas-liquid separator 7a annexed to the refrigerant regenerator 7 and the condenser 2.Installed between the condenser 2 and the evaporator 5 is a refrigerant liquid line (third refrigerant line) 12 having a throttle valve 11. A low concentration absorbent liquid line (first absorbent liquid line) 15 having a pump 14 is installed between the absorbing unit 3 and the heat recovering unit 9. A high concentration absorbent liquid line (second absorbent liquid line) 17 extending through the heat recovering unit 9 and having a throttle valve 16 is installed between the gas-liquid separator 7a of the regenerator 7 and the absorbing unit 3. There are a first circulation line 18 for absorbent liquid flowing from the engine 5 to the regenerator 7 and a second circulation line 19 for said absorbent liquid flowing to the heater 8.There are a first ventilation line 20 for air A flowing through said evaporator 5 into the car interior 4 and a second ventilation line 21 for said air flowing directly into the car interior 4, with a switching damper (switching means) 22 for switching between said first and second ventilation lines 20 and 21. The numeral 23 denotes an engine cooling liquid circulation pump; 24 denotes a three-way valve capable of switching between the engine cooling liquid circulation lines and controlling flow rate; 25 denotes a cooling fan for the condenser 2 and absorbing unit 3; and 26 denotes a ventilating or circulating fan for the car interior 4.In addition, the circulation lines 18 and 19 for the regenerator 7 for the engine cooling liquid and the heater 8 have been shown parallel, but they may be connected in series, as shown in Figs. 2(a) and 2(b), and switching between cooling and heating may be effected solely by manipulating the switching damper 22. Fig. 8 shows a method of attaining this on the basis of valve switching.

As the engine cooling liquid, use is made of silicone type synthetic oils having relatively high boiling points of 1200C and above, and it is preferable that the liquid be circulated at 1200-1400C through the circulation line 18.

Refrigerant-absorbent liquid combinations available are flon 22 (R 22)-dimethylformamide, flon 22-tetraethyleneglycol dimethyl ether, and flon 22-diethylene glycol ether, methanollithium bromide, and ammonia-water.

The operation will now be described.

(i) Air cooling: The refrigerant liquid leaving the condenser 2 flows through the throttle valve 11 and into the evaporator 5, where it is evaporated, absorbing heat from the air in the car interior 4 to effect air cooling. The refrigerant vapor resulting from evaporation flows through the refrigerant vapor line 13 and into the absorbing unit 3, where it is absorbed by the high concentration absorbent liquid. The low concentration absorbent liquid which has absorbed the refrigerant is fed by the pump 14 to the heat recovering unit 9, where it is preheated by heat exchange with the high concentration absorbent liquid. The preheated low concentration absorbent liquid is fed to the regenerator 7, where it is heated by the engine cooling liquid, and then in the gas-liquid separator 7a it is separated into refrigerant vapor and high concentration absorbent liquid.The refrigerant vapor is fed to the condenser 2, where it is condensed. On the other hand, the high concentration absorbent liquid is fed to the absorbing unit 3, where it absorbs refrigerant vapor from the evaporator 5, as described above. The heat generated in said condenser 2 and said absorbing unit 3 is removed into the outside by the cooling fan 27. The air cooling is effected by the aforesaid series of cycles, while the engine cooling is effected at the same time. In the case where the heat quantity of the engine cooling liquid is insufficient for the air cooling load, the heat quantity of the waste gas can be utilized.

Further, as shown in Fig. 1, in these heat exchangers, the refrigerant and absorbent liquid form the so-called through-flows.

The heat cycle performed during the aforesaid air cooling will now be described in more detail.

Flon 22 (R 22) was used as the refrigerant and dimethylformamide as the absorbent liquid. The relationship between temperature and pressure, at various DMF concentrations (DMF/(R 22 + DMF)), concerning this R22/DMF type absorbent liquid combination is as shown in Fig. 5. Silicone type synthetic oil is used as the engine cooling liquid and the engine cooling liquid flowing through the circulation line 18 is at 1200C-1400C. In the heat recovery unit 9 and regenerator 7, the low concentration absorbent liquid (point a 1, in Fig. 5) is heated to about 110"C--120"C (point al, point b1 in Fig. 5) and further heated; by separation of R-22, it is concentrated to a DMF concentration of about 47% (point b1 point c1 in Fig. 5).The generated R-22 vapor is condensed at 50"C in the condenser 2, and the condensed R-22 liquid is evaporated at 0 C (point e1 -- point f1 in Fig. 5) in the evaporator 5 to generate cool air. In the absorbing unit 3, the evaporated R-22 is absorbed by a high concentration absorbent liquid which has been cooled to 50"C (point c1 point dl in Fig. 5) in the heat recovery unit 9, so that the absorbent liquid becomes a low concentration absorbent liquid (point dl - al in Fig. 5). As described above, a series of cycles, regeneration, condensation, evaporation and absorption of the refrigerant R-22, are continuously repeated, thereby effecting air cooling and the cooling of the engine.Fig. 6 shows the relationship between temperature and pressure at various CH3OH concentrations ((CH30H/(CH30H + LiBr)) of CH3OH + LiBr type absorbent liquid combination using methanol (CH3OH) as refrigerant and lithium bromide (LiBr) as absorbent liquid for the refrigerant. In this case also, air cooling and engine cooling are effected by the same cycle (a2, b2, c2, d2, e2 and f2 in Fig. 6) as for the aforesaid R-22/DMF combination.

(ii) Air Heating: The engine cooling liquid is passed, by operating the three-way valve 24, from the second circulation line 19 to the heater 8 to produce hot air, whereby air heating is effected, and at the same time the engine is cooled.

(iii) Dehumidifying: The air dehumidified by cooling in the evaporator 5 is passed, by operating the switching damper 22, to the heater 8 where the engine cooling liquid is circulated, and it is dehumidified by being heated to a predetermined temperature.

In this embodiment, the condensation temperature attained from the open air temperature and the final absorption temperature (al) are 50"C and the regeneration temperature is 110-120"C; however, if the open air temperature is lower, the regeneration temperature may be lowered.

A second embodiment will now be described with reference to Fig. 3. The embodiment includes a bypass line 28 installed between the refrigerant liquid line 12 and the low concentration absorbent liquid line 15 shown in the first embodiment by way of a three-way valve 29. This three-way valve 29 is capable of controlling flow rate as well as direction. In the case, for example, of air heating, by operating the three-way valve 29 to use said bypass line 28, the refrigerant liquid is caused to flow into the low concentration absorbent liquid line 15. Thereupon, the refrigerant liquid, without passing through the evaporator 5, flows into the regenerator 7 and the absorbing unit 3, while the refrigerant vapor enters the condenser 2, where it becomes a refrigerant liquid.In this manner, a series of cycles, regeneration and condensation of refrigerant and its mixing with absorbent liquid, are performed, whereby the extra heat of the engine cooling liquid is released in the regenerator 7, making it possible to cool the engine. Further, in the case where neither air cooling nor air heating is to be effected, the engine can be cooled in exactly the same manner. Further, for air cooling, if the air cooling load is low, refrigerant regeneration by the regenerator 7 can be subjected to the load necessary for the consumption of heat removed by the cooling of the engine, whereby the engine can be cooled.

A third embodiment will now be described with reference to Fig. 4.

The third embodiment includes a bypass line 31 installed between the refrigerant liquid line 12 and the high concentration absorbent liquid line 17 shown in the first embodiment by way of a three-way valve 30 (having the same function as the aforesaid three-way valve 29).

This bypass line 31 functions in the same manner as the bypass line 28 in the second embodiment.

A fourth embodiment will now be described with reference to the drawings.

In Fig. 7, a vehicle 51 has mounted thereon a regenerator 53 which utilizes the heat of cooling liquid for an engine 52 to separate low concentration absorbent liquid into refrigerant vapor and high concentration absorbent liquid, a condenser 54 in which heat exchange with the open air is effected to condense the refrigerant vapor into refrigerant liquid, an intermediate absorbing unit (medium pressure absorbing unit) (intermediate absorbing means) 55 in which the refrigerant vapor is absorbed by the high concentration absorbent liquid, an evaporator 57 in which refrigerant liquid is subjected to heat exchange with the air in a car interior 56 including the open air and is thereby evaporated into refrigerant vapor and which, if necessary, condenses the refrigerant vapor into refrigerant liquid, a heater 58 which circulates the engine cooling liquid to heat the car interior 56, an absorbing unit (low pressure absorbing unit) 59 in which refrigerant vapor from the evaporator 57 is absorbed by medium concentration absorbent liquid from the intermediate absorbing unit 55, an intermediate evaporator (intermediate evaporating means) 60 which is integral with said absorbing unit 59 and in which refrigerant vapor from the condenser 54 is evaporated by the heat of absorption generated obtained in said absorbing unit 59 (the refrigerant vapor produced in intermediate evaporator being absorbed by the high concentration absorbent liquid in the intermediate absorbing unit 55), a first heat recovery unit 61 in which low concentration absorbent liquid from the absorbing unit 59 is subjected to heat exchange with medium concentration absorbent liquid from the intermediate absorbing unit 55 and is thereby heated, and a second heat recovery unit 62 in which said low concentration absorbent liquid is further subjected to heat exchange with a high concentration absorbent liquid from the gas-liquid separator 53a of the regenerator 53 and is thereby heated. A first refrigerant vapor line (second refrigerant line) 63 is installed between the gas-liquid separator 53a of the regenerator 53 and the condenser 54. A high concentration absorbent liquid line 65 is installed between the gasliquid separator 53a and the intermediate absorbing unit 55 by way of a second heat recovery unit 62. A valve 64a is placed somewhere between the ends of said high concentration absorbent liquid line 64. A medium concentration absorbent liquid line 65 is installed between the intermediate absorbing unit 55 and the absorbing unit 59 by way of a first heat recovery unit 61.In addition, the high and medium concentration absorbent liquid lines 64 and 65 form second absorbent liquid line. Installed between the intermediate evaporator 60 and the intermediate absorbing unit 55 is a second refrigerant vapor line (fifth refrigerant line) 66. A first refrigerant liquid line (third refrigerant line) having a valve 67 is installed between the condenser 5 and the evaporator 57, and a second refrigerant liquid line (fourth refrigerant line) 70 having a valve 69 is installed between an intermediate place on said first refrigerant liquid line 68 and the intermediate evaporator 60. A third refreigerant vapor line (first refrigerant line) 71 is installed between the evaporator 57 and the absorbing unit 59.A low concentration absorbent liquid line (first absorbent liquid line) 73 having a pump 72 is installed between the evaporator 57 and the regenerator 53 by way of the first and second heat recovery units 61 and 62. A first circulation line 74 for circulation of engine cooling liquid is installed between the engine 52 and the regenerator 53, and a second circulation line 75 for circulating engine cooling liquid by way of the first circulation line 74 is installed between the engine 52 and the heater 58. The first circulation line 74 is provided with a pump 76 and the second circulation line 75 is provided with a valve 77. There are a first ventilation line 78 through which air B which has passed through the evaporator 57 flows directly into the car interior 56, and a second ventilation line 79 into which said air flows after passing through the heater 58.And there is also a switching damper 80 for switching between the first and second ventilation lines 78 and 79. The numeral 81 denotes a cooling fan for the condenser 54 and intermediate absorbing unit 55 and 82 denotes a fan for feeding air into the car interior or for circulating air. In addition, in Fig. 7, the circulation lines 74 and 75 for circulation of engine cooling liquid through the regenerator 53 and the heater 58 have been installed parallel to each other, but as shown in Fig. 8, the forward passage of the first circulation line 74 may be connected to the return passage of the second circulation line 75 by a bypass line 84 having a valve 83. In that case, switching between air cooling and air heating is effected by the switching damper 80. In addition, in Fig. 8, the numeral 85 denotes a valve installed in the first circulation line 74.

Fig. 9 shows a fifth embodiment which is a modification of Fig. 7. That is, a refrigerant bypass line 87 having a valve 86 is installed between the upstream side of the valve 67 in the first refrigerant liquid line 68 and the suc tion side of the pump 72 for the low concentration absorbent liquid line 73 shown in Fig.

7.

Fig. 10 shows a sixth embodiment which is a modification of Fig. 9. That is, a high concentration absorbent liquid bypass line 89 having a valve 88 is installed between the high concentration absorbent liquid line 64 and the refrigerant liquid bypass line 87 and between the medium absorbent liquid line 65 and the absorbent liquid bypass line 87 shown in fig.

9. In addition, 64a denotes a valve placed in the high concentration absorbent liquid line 64.

Fig. 11 shows a seventh embodiment which is a modification of Fig. 7. That is, a refrigerant vapor bypass line 92 having a valve 91 is installed between the first refrigerant vapor line 63 and a place intermediate between the ends of the third refrigerant vapor line 71 shown in Fig. 7.

The operation will now be described.

(i) Air Cooling: The refrigerant vapor separated in the gasliquid separator 53a of the regenerator 53 is subjected to heat exchange with the open air in the condenser 54 and is thereby condensed into refrigerant liquid. This refrigerant liquid is divided into two parts, one being fed to the evaporator 57 through the first refrigerant liquid line 67 and the other being fed to the intermediate evaporator 60 through the second refrigerant liquid line 70. The high concentration absorbent liquid separated in the gas-liquid separator 53a is subjected to heat exchange with the low concentration absorbent liquid in the second heat recovery unit 62 and is thereby cooled, whereupon it is fed to the intermediate absorbing unit 55 through the high concentration absorbent liquid line 64.The refrigerant liquid fed to the intermediate evaporator 60 is subjected to heat exchange to receive the heat produced when the refrigerant vapor fed from the evaporator 57 is absorbed by the absorbent liquid, and it is thereby evaporated. This medium pressure refrigerant vapor is fed to the intermediate absorbing unit 55, where it is absorbed by the high concentration absorbent liquid, thus becoming a medium concentration absorbent liquid. And this medium concentration absorbent liquid is fed to the first heat recovery unit 61, where it is subjected to heat exchange with the low concentration absorbent liquid, whereupon it is fed to the absorbing unit 59.On the other hand, the refrigerant liquid fed to the evaporator 57 absorbs, in this evaporator 57, the heat from the air in the car interior 56, which air, if necessary, includes the open air, and is thereby evaporated, thus effecting air cooling. The low pressure refrigerant vapor generated is fed to the absorbing unit 59 through the third refrigerant vapor line 71 and is absorbed by the absorbent liquid, thus the latter becoming a low concentration absorbent liquid. At this time, the heat of absorption generated is utilized for evaporation of the refrigerant liquid in the intermediate evaporator 60. The low concentration absorbent liquid is subjected to heat exchange with the medium concentration absorbent liquid in the first heat recovery unit 61, and it is subjected to heat exchange with the high concentration absorbent liquid in the second heat recovery unit 62.And it is fed to the regenerator, where it is heated by the engine cooling liquid and thereby separated into refrigerant vapor and high concentration absorbent liquid. Air cooling is effected by a series of cycles of two-stage absorption type, high concentration absorbent liquid -medium concentration absorbent liquid, medium concentration absorbent liquid-low concentration absorbent liquid, as described above, and the liberation of the heat retained by the engine cooling liquid, i.e., the cooling of the engine is effected. And said series of cycles in air cooling are also performed for cooling the engine.

The heat cycle in the aforesaid air cooling will now be described in more detail.

Flon 22 (Ft 22) was used as the refrigerant and dimethylformamide (DMF) as the absorbent liquid for the refrigerant. The relationship between temperature and pressure at various DMF concentrations (DMF/(R 22 + DMF)) of this R 22/DMF refrigerant-absorbent liquid combination is as shown in Fig. 12 and indicates the two-stage absorption refrigeration cycle to be described below. The engine cooling liquid flowing through the first circulation line 74 is circulated at 90"C--100"C. Low ccncentration absorbent liquid with a DMF concentration of about 28% (point a in Fig.

12) is heated to about 82"C (point a ~ point b in Fig. 12) by the first and second heat recovery units 61 and 62 and the regenerator 53, and it is further heated to about 90"C, separating R 22 and it is concentrated to a DMF concentration of about 31.5% (point b point c in Fig. 12). The R 22 vapor generated is condensed at 50oC (point g in Fig. 12) in the condenser 54. The R 22 liquid from this condensation is divided into two parts, one of which is evaporated at about 20"C (point h in Fig. 12) in the intermediate absorbing unit 60.

In the intermediate absorbing unit 55, this R 22 vapor is absorbed by the high concentration absorbent liquid which has been cooled (point c --, point d in Fig. 12) by heat ex- change with the low concentration absorbent liquid in the second heat recovery unit 62, thus becoming a medium concentration absorbent liquid (point d , point e in Fig. 12). The other part of said R 22 liquid is evaporated at about 0 C (point i in Fig. 12) in the evaporator 57, producing cold air.The evaporated R 22 is absorbed, in the absorbing unit 59, by the medium concentration absorbent liquid with a DMF concentration of about 30% which has been cooled to about 28"C (point e ~ point f in Fig. 12) by heat exchange with the low concentration absorbent liquid in the first heat recovery unit 61, thus becoming a low concentration absorbent liquid. The heat absorbed this time is used, through heat exchange, for evaporation of the R 22 liquid in the intermediate evaporator 60.As described above, a series of two-stage absorption cycles, regeneration -condensation-intermediate absorption (medium pressure absorption)-absorption (low pressure absorption) of refrigerant R 22, are continuously repeated to effect air cooling and engine cooling by liberating the heat retained by the engine cooling liquid. Fig. 13 illustrates a series of two-stage absorption cycles for H20-LiBr type refrigerant-absor- bent liquid, using water (H20) as the refrigerant and lithium bromide (LiBr) as the refrigerant absorbing liquid. This example illustrates a cycle in which the LiBr concentrations of the absorbent liquid in the absorbing unit 59 and intermediate absorbing unit 55 are reverse to those for the R 22-DMF type.

Operating modes other than those for air cooling will now be described in detail.

- 23 (ii) Air Heating (1): The engine cooling liquid is fed also to the heater 58 through the first circulation line 74 to heat the car interior 56 and if there is surplus heat, a series of cycles for the aforesaid air cooling (i) are performed irrespective of the air conditioning of the car interior 56, so as to cool the engine. In this case, by means of valves 85, 77 and 83 placed in the circulation lines 74 and 75 and bypass line 84, the engine cooling liquid flow rate is adjusted to the load.

(iii) Air Heating (2): As in the case of (ii), the engine cooling liquid is fed to the heater 58 through the first circulation line 74 to heat the car interior 56.

And if there is surplus heat retained by the engine cooling liquid, as shown in Fig. 9, part of the refrigerant liquid from the condenser 54 is mixed with the absorbent liquid flowing out directly from the absorbing unit 59, by way of the refrigerant liquid bypass line 87. In the rest of the process that follows, exactly the same cycle as in the air cooling (i) is performed to liberate the heat retained by the engine cooling liquid, so as to cool the engine.

(iv) Air Heating (3): As in the case of (ii), the engine cooling liquid is fed to the heater 58 through the first circulation line 74 to heat the car interior 56.

And if there is surplus heat retained by the engine cooling liquid, as shown in Fig. 10, the high concentration absorbent liquid which should be fed to the intermediate absorbing unit 55 in the case of the air cooling cycle (i) is mixed directly with the refrigerant liquid by way of the high concentration absorbent liquid bypass line 89, whereby it is turned into a low concentration absorbent liquid. And this low concentration absorbent liquid is fed to the regenerator 53, where it is heated by the engine cooling liquid for separation into refrigerant vapor and high concentration absorbent liquid, whereby the surplus heat retained by the engine cooling liquid is liberated to cool the engine.

(v) Air Heating (4):.

As in the case of (ii), the engine cooling liquid is fed to the heater 58 through the first circulation line 74 to heat the car interior 56.

And if there is surplus heat retained by the engine cooling liquid, as shown in Fig. 11, part of the refrigerant vapor from the gasliquid separator 53a is fed to the evaporator 57 through the refrigerant vapor bypass line 62 and third refrigerant vapor line 71, causing the evaporator to function as a condenser.

The heat of condensation produced can be utilized for heating the air in the car interior 56, and the refrigerant liquid resulting from condensation is fed to the low concentration absorbent liquid line 73 through the refrigerant liquid bypass line 87. In the case where part of the refrigerant vapor from the gas-liquid separator 53a is condensed, the resulting refrigerant liquid together with the refrigerant liquid from said evaporator 57a is fed to the low concentration absorbent liquid line 73 through the bypass line 87. The low concentration absorbent liquid is heated by the engine cooling liquid in the regenerator 53 in the same manner as described above. In this manner, the flow rate of the refrigerant vapor fed to the evaporator 57 is adjusted by the valve 91 to the air heating load and at.the same time the engine is cooled.

(vi) Dehumidifying: The air cooled and dehumidified by performing the same cycle as in the air cooling (i) is fed to the second ventilation line 79 associated with the heater 58 by operating the switching damper 80, while the engine cooling liquid is circulated through the heater 58 and is thereby heated to a predetermined temperature, whereby the air in the car interior 56 is dehumidified and at the same time the engine is cooled.

(vii) Engine Cooling: In the case where neither air heating or cooling nor dehumidifying is performed (which corresponds to the case where in (i) through (vi) above, the load becomes zero during air cooling, air heating or dehumidifying), a series of cycles, such as evaporation (evaporation in the intermediate evaporator) and absorption, are performed irrespective of the cooling or heating of the air in the car interior 56 (with the fan 82 stopped) to liberate the heat retained by the engine cooling liquid, thus cooling the engine.

In the case where the load for the aforesaid air cooling or heating or dehumidifying is so high that the heat retained by the engine cooling liquid is insufficient, it is possible to utilize the heat retained by the engine waste gases.

A first embodiment of a cooling device for vehicles according to the present invention will new be described with reference to Fig. 14.

The numeral 101 denotes an absorption typecooling device mounted on an automobile (vehicle), using flon 22 (R 22) as a refrigerant and dimethylformamide, tetra-ethyleneglycol-dimethylether or dibytylethyleneglycol dimethyl ether as an absorbent liquid. The cooling device 101 comprises a cooling device body 102 in which absorbing means, regenerating means and condensing means are integrated together, an evaporator (evaporating means) 104 separated from said cooling device body 102 and disposed in a car interior 103 to serve as a heat exchanger for car interior cooling purposes, and a radiator (radiating means) for radiating the heat from the absorbing means and condensing means into the outside. Hot water in an engine cooling water radiator 106 is used as a heat source for the regenerating means.The cooling device body 12 is of the laminated and integrated type comprising first plate bodies 111 each having formed therein an absorbing compartment (absorbing means) 107, a heat exchange compartment 108, a regenerating compartment (regenerating means) 109 and a condensing compartment (condensing means) 110, and second plate bodies 116 each having formed therein an absorbing compartment cooling water passage 112, a heat exchange fluid passage 113, a regenerating compartment heating water passage 114, and a condensing compartment cooling water passage 115, said first and second plate bodies being alternately arranged through heat transfer plates (not shown) to form a block. There is a first refrigerant transfer line 117 which introduces the refrigerant condensed in the condensing compartment 110 into the evaporator 104.There is a second refrigerant transfer line 118 which introduces the refrigerant evaporated in the evaporator 104 into the absorbing compartment 107. There is a low concentration absorbent liquid transfer line 119 whereby the low concentration absorbent liquid which has absorbed the refrigerant in the absorbing compartment 107 is introduced into the generating compartment 109 through the heat exchange fluid line 113. There is a cooling water line 120 which introduces the cooling water in the radiator 105 disposed forwardly of the radiator 106 into the absorbing compartment cooling water passage 112 and the condensing compartment cooling water passage 115.

There is a heating water line 121 which introduces the hot water in the radiator 106 into the regenerating compartment heating water passage 114 through the engine cooling chamber. The aforesaid lines 119, 120 and 121 have transfer pumps 122, 123 and 124 placed therein, respectively.

The operation will now be described.

The refrigerant leaving the condensing compartment 110 enters the evaporator 104, where it absorbs the heat in the car to effect cooling. The refrigerant vaporized as it absorbs heat enters the absorbing compartment 107, where it is absorbed by the absorbent liquid. The low concentration absorbent liquid which has absorbed the refrigerant is transferred to the regenerating compartment 109.

The low concentration absorbent liquid entering the regenerating compartment 109 is heated by the hot water from an engine 125 and is thereby evaporated. The evaporated refrigerant enters the condensing compartment 110, where it is condensed by the cooling water from the radiator 105 which is flowing through the condensing compartment cooling water passage 115 and then it is returned to the evaporator 104. On the other hand, the high concentration absorbent liquid left in the regenerating compartment 109 is returned to the absorbing compartment 107 through the heat exchange compartment 108. In addition, the heat retained by the high concentration absorbent liquid is imparted to the low concentration absorbent liquid flowing through the heat exchange fluid passage 113; thus, heat recovery is effected.Further, the heat of condensation produced in the absorbing compartment 107 is imparted to the cooling water flowing through the absorbing compartment cooling water passage 112 and is radiated into the outside by the radiator 105.

A second embodiment of the second form of the invention will now be described with reference to Fig. 15.

In this cooling device 131, the condensing means, i.e., the condensing compartment 110 in the first embodiment described above is separated, as the evaporator 104 is, from the cooling device body 102 to serve as a condenser 132, the latter being disposed forwardly of the radiator 106 so that it is cooled directly by air cooling without the intermediary of cooling water. The condenser 132 is an example of the condensing means and is of air cooled type as the radiator is. In addition, the heating water line 121 leading to the regenerating compartment heating water line 114 may be connected directly to the cooling chamber of the engine 125.

Claims

1. An air conditioner adapted to be installed in a vehicle, comprising evaporating means for evaporating a refrigerant liquid to cool car interior air, absorbing means in which refrigerant vapor from said evaporating means is absorbed by an absorbent liquid, regenerating means in which low concentration absorbent liquid which has absorbed refrigerant liquid in said absorbing means is heated by the heat of an engine cooling liquid to evaporate the refrigerant, condensing means for cooling refrigerant vapor from said regenerating means to condense said refrigerant vapor, a first refrigerant line for introducing refrigerant vapor from said evaporating means into said absorbing means, a first absorbent liquid line including a circulation pump for introducing the low concentration absorbent liquid from said absorbing means into said regenerating means, a second refrigerant line for introducing refrigerant vapor from said regenerating means into said condensing means, a third refrigerant line with a throttle valve for introducing the refrigerant liquid from said condensing means into said evaporating means, a second absorbent liquid line with a throttle valve for introducing a high concentration absorbent liquid from said regenerating means into said absorbing means, heating means for heating car interior air, a circulating line for circulating the engine cooling liquid through said heating means and said regenerating means, a first ventilating line for introducing air cooled by said evaporating means directly into the car interior, a second ventilating line for introducing said air into the car interior through said heating means, and switching means for selectively switching said first and second ventilating lines.

2. An air conditioner as set forth in Claim 1, using high-boiling synthetic oil as an engine cooling liquid.

3. An air conditioner as set forth in Claim 1, including a bypass line installed between the third refrigerant liquid line and the first absorbent liquid line.

4. An air conditioner as set forth in Claim 4, including a bypass line installed between the third refrigerant liquid line and the second absorbent liquid line.

5. An air conditioner as set forth in Claim 1, including intermediate absorbing means disposed somewhere between the ends of the second absorbent liquid line for absorbing refrigerant vapor, intermediate vapor generating means for evaporating the refrigerant by the heat of absorption generated by the absorbing means, a fourth refrigerant line for introducing part of the refrigerant liquid from the condensing means into said intermediate evaporating means, and fifth absorbing means for introducing the refrigerant vapor from said intermediate evaporating means into said intermediate absorbing means.

6. An air conditioner as set forth in Claim 5, including a refrigerant bypass line installed between the first absorbent liquid line and the third refrigerant line.

7. An air conditioner as set forth in Claim 6, wherein the intermediate absorbent means installed in the second absorbent liquid line is bypassed and there is a absorbent liquid bypass line which connects the second absorbent liquid line to the refrigerant bypass line.

8. An air conditioner as set forth in Claim 5, including a refrigerant bypass line installed between the first and second refrigerant lines.

9. An air conditioner for vehicles wherein an absorbing type cooling device having evaporating means, absorbing meals and regenerating means is mounted on a vehicle, said evaporating means being separated from the cooling device body and serving as heat exchange means for cooling the car interior, said cooling device body comprising first plate bodies each having at least formed therein an absorbing compartment and a regenerating compartment, and second plate bodies each having formed therein cooling and heating water passages for cooling and heating said compartments, respectively, said first and second plate bodies being united through heat transfer plates into laminate form, the arrangement being such that the heat from said absorbing compartment and said condensing means is radiated through heat radiating means installed forwardly of an engine cooling water radiator and hot water in the engine cooling water radiator is introduced into the regenerating compartment heating water passage.

10. An air conditioner as set forth in Claim 9, wherein each first plate body is formed with an absorbing compartment, a regenerating compartment and a heat exchange compartment.

11. An air conditioner as set forth in Claim 9, wherein each plate body is formed with an absorbing compartment, a regenerating compartment, a condensing compartment and a heat exchange compartment.

12. An air conditioner for vehicles substantially as described herein with reference to and as illustrated in the accompanying drawings.