JPS5938113A - Air conditioner of heat pump type for vehicle - Google Patents

Abstract

PURPOSE:To prevent the corrosion of an evaporation, the clinging of soot and the decomposition of a coolant and refrigerating machine oil in an air conditioner of heat pump type which employs the exhaust heat of an engine, by using a rotary heat exchanger to perform heat exchange between the exhaust gas of the engine and intake air to conduct the heated air to the evaporator. CONSTITUTION:Exhaust gas S2 is introduced into a rotary heat exchanger 23 from an exhaust pipe 25. Air S4 is introduced into the heat exchanger from an air duct 22. Heat exchange is effected between the exhaust gas and the air. When the S4 is not introduced into the heat exchanger 23, the exhaust gas S2 is discharged as scarcely-changed gas S3 and room heating is not effected. When the air S4 is introduced into the heat exchanger, the heated air S5 is delivered to an evaporator 25 so that the air is further heated and then released into the riding room of a vehicle to heat the room. Since only the clean air flows through the evaporator 25, it does not corrode, no soot clings thereto and a coolant etc. are not decomposed. The capacity of air conditioning can easily be adjusted by controlling the revolution speed of the heat exchanger 23.

Description

[Detailed Description of the Invention] The present invention provides a vehicle heating system that utilizes engine exhaust heat.
The present invention relates to a 9-inch type air conditioner.

BACKGROUND ART Many air conditioners of this type have been proposed in the past, and aim to improve comfort and save energy by utilizing exhaust heat, which would normally be wasted, in a heat pump system. One example is shown in FIGS. 1 to 3.

This air conditioner uses an engine 1 to drive a compressor 2 during heating operation. High-temperature, high-pressure refrigerant gas discharged from the compressor 2 flows in the direction of arrow S1 through the switching valve 3, passes through the switching valve 4, and enters the heat exchanger 5. flows into. The heat exchanger 5 is installed in the vehicle compartment 6, and the refrigerant radiates heat and condenses by blowing air with the blower 7 and exchanging heat. The refrigerant condensed in the heat exchanger 5 is transferred to the switching valves 8, 9 . Receiver 10
．． After passing through the switching valve 1 and expanding with the expansion valve 12, the evaporator 13
flows into. This evaporator 13 is in contact with the engine exhaust heat, and the refrigerant evaporates while absorbing the engine exhaust heat, and returns to the compressor 2 through the switching valve 14 in a heat ponzo operation.

As shown in FIG. 3, this evaporator 13 is directly inserted into a branch pipe 16 of an exhaust pipe 15, and has a structure in which exhaust gas is directly sent into the branch pipe 16 by operating an exhaust gas switching damper 17. .

Therefore, depending on the operating condition of the evaporator 13, the width of
Exposure to high temperatures of 0-1000℃.

Furthermore, when the engine 1 is stopped, the compressor 2 is also stopped, and the refrigerant remains and is overheated by the residual heat in the exhaust pipe 15. As a result, there is a problem in that the refrigerant and refrigerating machine oil inside the evaporator 13 are thermally decomposed. Furthermore, soot adheres to the evaporator 13, clogging the fin tubes and the like, increasing resistance on the exhaust gas side and reducing thermal efficiency. Furthermore, there are problems such as dew condensation occurring below the exhaust gas dew point and sulfuric acid corrosion caused by sulfur in the fuel.

As mentioned above, the evaporator of a vehicle heat pump type air conditioner that uses exhaust heat from the engine has problems with durability.
There are many technical challenges, such as realizing a mechanism for finely adjusting the exhaust gas temperature, selecting materials with high corrosion resistance, and selecting refrigerants and refrigeration oil with high heat resistance. For this reason, although various proposals have been made in the past, they have not been realized.

The present invention was made in view of the above circumstances, and its purpose is to prevent corrosion of the evaporator.

The object of the present invention is to obtain a heat pump type air conditioner for vehicles that prevents soot adhesion and decomposition of refrigerant and refrigerating machine oil, and also allows easy adjustment of heating capacity.

That is, the present invention provides a heat pump type air conditioner for a vehicle equipped with an engine-driven conzoresor, a heat ventilator, a receiver + an expansion valve, and an evaporator, which is provided adjacent to an exhaust pipe from the engine. A forced ventilation air duct, a rotary heat exchanger communicating with the air duct and the exhaust pipe, respectively, and an evaporator installed on the downstream side of the rotary heat exchanger in the air duct. This is a heat pump type air conditioner for vehicles.

The present invention will be described below with reference to illustrative embodiments.

The air conditioner according to the present invention has the same overall configuration as that shown in FIG. 2, but is characterized in that the evaporator is not exposed directly to the exhaust gas but is brought into contact with the heat-exchanged air.

That is, as shown in FIG. 4, the exhaust pipe 15 from the engine
An air duct 21 is provided adjacent to the air duct 21.
A blower 22 is used to provide forced ventilation. A rotary heat exchanger 23 is installed between the exhaust pipe 14 and the air duct 21 so as to communicate with the exhaust pipe 14 and the air duct 2 . As shown in FIG. 5, the heat exchanger 23 is made of a material with a large heat storage effect, such as a steel plate or a ceramic material, and is formed into a honeycomb shape or a great fin shape, and is rotationally driven by a motor 24. And the evaporator 25 is connected to the air duct 2
It is installed on the downstream side of the rotary heat exchanger 23 of No. 1.

When the engine 1 is running and heating operation is not necessary, this device operates the compressor 2, motor 24,
Stop the fan/machine 22. Therefore, the exhaust gas flow St
passes through a portion corresponding to the diameter of the exhaust pipe 15 of the rotary heat exchanger 23, and flows to the end as shown by arrow S3 with almost no temperature drop. In this case, the temperature of the rotary heat exchanger 23 becomes high only in the portion where the exhaust gas passes through, and the temperature rise in other parts is small.

During heating operation, the motor 24 and the blower 22 are driven simultaneously with the compressor 2 by switches 1 and 4 not shown. The part of the rotary heat exchanger 23 inside the exhaust pipe 15 is heated by the high-temperature exhaust gas flow S2 and heat is stored therein, but when the motor 24 rotates in the direction of arrow R, the air flow S4 is generated on the air duct 21 side. The heat is exchanged by the air, and high-temperature air 5 comes out. Furthermore, the FA generator 25 is activated by the high temperature air flow S11.
is heated, evaporation of the refrigerant and endothermic action occur. Since the rotary heat exchanger 23 rotates continuously, heat is stored on the exhaust gas side, heat is radiated on the gust side, and heat is absorbed in the evaporator 25.

If engine 1 is stopped, rotary heat exchanger 2j is 15,
Exhaust pipe residual heat does not transfer to the evaporator side.

According to this air conditioner, the exhaust gas does not come to the evaporator side, so corrosion of the evaporator does not occur, soot does not adhere to the evaporator, and there is also an abnormality in the refrigerant or refrigeration oil in the evaporator. No decomposition occurs due to overheating. Therefore, the durability of the evaporator is significantly improved. Furthermore, if the rotary heat exchanger is rotated at the first speed, it will have a high heating capacity, and if it is rotated at a low speed, it will have a low heating capacity, so the heating capacity can be easily adjusted to match the heating load, improving controllability. . Furthermore, Ennon begins NJ
After IIF, heat pump operation with good startup performance that generates warm air becomes possible, improving comfort.

As described above, according to the present invention, a rotary heat exchanger is provided to prevent exhaust gas from directly touching the evaporator, which improves the durability of the evaporator and further improves heating controllability and comfort. Trees have a noticeable effect.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the arrangement of a conventional vehicle air conditioner, FIG. 2 is a refrigerant circuit diagram of the same, and FIG. 3 is a diagram showing the arrangement of an evaporator constituting the device. FIG. 4 is an explanatory view of essential parts of a vehicle air conditioner showing an embodiment of the present invention, and FIG. 5 is a sectional view taken along line V-V in FIG. 4. 1...Engine, 2...Compressor, 3,4゜8
．． 9,11.14...Switching valve, 5...Heat exchanger, 6
... Vehicle interior, 7... Blower, 10... Receiver, 1
2... Expansion valve, 13... Evaporator, 15... Exhaust pipe, 16... Branch pipe, 17... Exhaust gas switching damper, 2
DESCRIPTION OF SYMBOLS 1... Air duct, 22... Blower, 23... Rotary heat exchanger, 24... Motor, 25... Evaporator.

Claims (1)

[Claims] In a vehicle heat pump type air conditioner equipped with a compressor driven by an engine, a #exchanger, a receiver 2 expansion valve, and an evaporator, a forced air duct provided adjacent to an exhaust pipe from the engine; and a rotary heat exchanger communicating with the air duct and the exhaust pipe, respectively, and the evaporator is straddled on the downstream side of the rotary heat exchanger in the air duct. .