JPH027688Y2 - - Google Patents

Description

[Detailed description of the invention] [Purpose of the invention] [Field of industrial application] The present invention relates to a heat pipe type automobile heating device, and in particular to an improvement in the structure of returning the working fluid in the heat pipe to the heat receiving part of the heat pipe. Regarding.

(Prior Art) Conventionally, a heat pipe type automobile heating system that uses the heat of engine exhaust gas to heat the interior of a car has been developed using a heat pipe heating system that heats the interior of a car using the heat of engine exhaust gas, as shown in Japanese Patent Laid-Open No. 52-24617, for example. There is a known system in which the heat receiving part of the heat pipe is placed inside the exhaust pipe, and the heat radiating part of the heat pipe is placed inside the heating air duct, so that the heat of the exhaust gas is transferred to the air inside the air duct using the heat pipe. It is being

(Problem to be solved by the invention) However, in this type of conventional heat pipe type automobile heating system, the working fluid is immediately returned to the heat receiving part of the heat pipe after the engine is stopped. There is a risk that the temperature will rise rapidly, melting the plastic parts, or causing the heat pipe to burst due to the sudden increase in internal pressure.

Therefore, some companies provide a liquid storage tank that once receives the working fluid heated and condensed in the heat radiation part and then returns it to the heat reception part, and a liquid return path with an on-off valve is provided on the outlet side of the tank, so that after the engine is stopped, the It has been proposed to close the on-off valve and leave the working fluid stored in the liquid storage tank.

However, with this method, if water is used as the working fluid when the outside temperature is below freezing, the working fluid will freeze, and even if you open the on-off valve to start the heat pipe operation, the working fluid will freeze. There is a problem in that the liquid does not return to the heat receiving part, and the operation continues for a long time until the liquid in the storage tank is naturally defrozen.

The present invention was developed in view of the current situation, and it is possible to prevent the working fluid from freezing by returning the working fluid to the heat receiving part, and even if the working fluid is returned to the heat receiving part, the heat pipe temperature does not rise rapidly. An object of the present invention is to provide a heat pipe type automobile heating device that can prevent

[Structure of the idea]

(Means for Solving the Problems) The present invention is characterized by providing a working fluid return means that opens the on-off valve of the liquid reservoir tank for a predetermined time after a predetermined time elapses after the engine is stopped.

(Function) In the heat pipe type automobile heating device according to the present invention, after a predetermined time has elapsed after the engine has stopped, the on-off valve is opened for a predetermined time in response to a signal from the working fluid return means. As a result, the working fluid in the liquid storage tank is returned to the heat receiving section.

By the way, the on-off valve does not open immediately after the engine stops, but after a certain period of time has passed. For this reason, the temperature of the heat receiving part has dropped to some extent,
Even if the working fluid is returned to the heat receiving section, the heat pipe temperature will not rise suddenly.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

In FIG. 1 showing the first embodiment, reference numeral 1 denotes an exhaust pipe that discharges exhaust gas 3 from an engine 2. A heat receiving part 4 of a heat pipe is inserted into this exhaust pipe 1, and its outer periphery is Fins 5 are provided on the surface to increase the outer surface area and improve heat exchange efficiency.
The working fluid such as water sealed in the heat pipe exchanges heat with the exhaust gas 3 in the exhaust pipe 1 in this heat receiving part 4 and evaporates, and passes through the axial center of the heat receiving part 4 for heat dissipation, which will be described later. The signal is sent to the section 6 side.

A heat dissipation section 6 of a heat pipe having a large number of fins 8 for heat exchange is inserted into an air duct 7 (not shown) that supplies heated air into the vehicle interior.
The working fluid turned into steam in the heat receiving section 4 is guided to the heat radiating section 6 through a steam passage tube 9 of a heat pipe. The cold air 11 from the fan 10 flowing through the air duct 7 is heated while passing through the heat radiating section 6, and is then blown into the vehicle.

On the other hand, due to heat exchange with the cold air 11, the heat radiation part 6
The condensed and liquefied working fluid is transferred to the heat pipe's liquid storage tank 13 via the heat pipe's recovery pipe 12.
The heat-receiving portion 4 is further recovered to the inner circumferential surface of the heat receiving portion 4 via a working fluid return pipe 14 having an electromagnetic on-off valve 15 and the steam passage pipe 9. The electromagnetic on-off valve 15 is connected to the control device 1.
In response to a control signal from 6, the opening is opened for a predetermined period of time after the engine 2 has stopped.

That is, the control device 16 has the engine 2
The engine stop signal from the ignition key 17 and the heat receiving part temperature signal from the sensor 18 provided in the heat receiving part 4 are respectively inputted, and from this control device 16, the stop of the engine 2 is inputted. When the temperature of the post-heat receiving section falls below, for example, 150° C., an open signal is output to the electromagnetic on-off valve 15 for a certain period of time. The time that the electromagnetic on-off valve 15 is open varies depending on the flow rate, the orifice diameter (liquid passage diameter) of the electromagnetic on-off valve 15, or the pressure difference, but all the working fluid in the liquid storage tank 13 returns to the heat receiving part 4. Can be set at any time.

Next, the operation of this embodiment will be explained.

A heat receiving section 4 of a heat pipe disposed within the exhaust pipe 1 is heated by exhaust gas from the engine 2 flowing through the exhaust pipe 1, and the working fluid within the heat receiving section 4 absorbs the heat and evaporates. Then, the working fluid that becomes steam and increases its pressure,
It is sent out through the axial center of the heat receiving section 4 and guided to the heat radiating section 6 through the steam passage pipe 9.

The high-temperature working fluid led to the heat dissipation part 6 exchanges heat with the cold air 11 flowing in the air duct 7 to condense and reduce the pressure, and the liquefied working fluid passes through the recovery pipe 12 to the liquid reservoir. It is collected in tank 13.
The working fluid recovered in the liquid storage tank 13 passes through the working liquid return pipe 14 and the steam passage pipe 9 to the heat receiving part 4.
is returned to the inner circumferential surface of the

Thereafter, the cycle is repeated and the air duct 7
The cold air 11 inside is heated, becomes warm air, and is discharged into the vehicle (not shown). As a result, the temperature inside the vehicle gradually increases.

On the other hand, when heating is to be stopped, the engine 2 is stopped and the electromagnetic on-off valve 15 is closed. As a result, heat transfer by the heat pipe is stopped and heating is stopped.

By the way, if the electromagnetic on-off valve 15 is kept closed and the working fluid is left stored in the liquid reservoir tank 13, when the outside temperature drops below freezing, if water is used as the working fluid, the working fluid will be stored in the liquid reservoir tank 13. Even if the electromagnetic on-off valve 15 is opened to start the operation of the heat pipe, the working fluid does not reach the heat receiving part 4.
There is a problem that the operation does not return to normal and the operation continues for a long time until the freeze inside the liquid storage tank 13 is naturally released.

Furthermore, if the working fluid is returned to the heat receiving section 4 before the temperature of the heat receiving section 4 falls below a certain level, the heat pipe temperature may rise rapidly and the heat pipe may burst.

Therefore, in this embodiment, the working fluid in the liquid storage tank 13 is returned to the heat receiving part 4 after the temperature of the heat receiving part 4 falls below a certain level.

That is, when the engine 2 stops, an engine stop signal from the ignition key 17 is input to the control device 16, and a heat receiving part temperature signal from the sensor 18 is input to the control device 16. Then, when the signal from the sensor 18 falls below, for example, 150°C, the controller 16 sends a signal to the solenoid on-off valve 1.
5, an open signal is output for a certain period of time. As a result, the electromagnetic on-off valve 15 opens and the entire amount of the working fluid in the liquid storage tank 13 is returned to the heat receiving section 4 .

Since the working fluid in the liquid storage tank 13 is returned to the heat receiving section 4 after the temperature of the heat receiving section 4 falls below a certain level, the temperature of the heat pipe does not rise suddenly.

FIG. 2 shows another embodiment of the present invention, in which the opening and closing operations of the electromagnetic on-off valve 15 are performed by signals from a timer 19.

That is, the timer 19 measures the temperature drop after the engine is stopped in advance so that the heat receiving section 4 can operate, for example.
A time period for the temperature to drop below 150° C. is set, and the timer 19 outputs an opening signal to the electromagnetic on-off valve 15 for a predetermined period of time after the engine 2 has stopped and this set period of time has elapsed.

In this way, by using the timer 19,
Similar effects can be obtained with a simpler structure than the previous embodiment.

[Effect of idea]

As explained above, in the present invention, the on-off valve provided in the liquid return path of the heat pipe is opened for a predetermined period of time after a predetermined period of time has elapsed after the engine has stopped, using the working fluid return means. It is possible to prevent the working fluid from freezing and also to prevent the temperature of the heat pipe from rising rapidly.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram of a heat pipe type automobile heating device showing one embodiment of the present invention, and FIG. 2 is a diagram equivalent to FIG. 1 showing another embodiment of the present invention. 1...Exhaust pipe, 2...Engine,
3... Exhaust gas, 4... Heat receiving section, 6... Heat radiating section,
7... Air duct, 9... Steam passage pipe, 13...
Liquid storage tank, 14... Working fluid return pipe, 15... Solenoid on-off valve, 16... Control device, 17... Ignition key, 18... Sensor, 19... Timer.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. The heat receiving part of the heat pipe, which is placed in the exhaust pipe of the engine and heats the internal working fluid by the exhaust gas from the engine, and the heat radiation part of the heat pipe, which is placed in the heating air duct. a steam passage tube of a heat pipe that guides the working fluid heated and evaporated in the heat receiving part to the heat radiating part; and a liquid reservoir that once receives the working fluid that has radiated heat and condensed in the heat radiating part and then returns it to the heat receiving part. tank and
It is characterized by comprising an on-off valve provided in the liquid return path on the outlet side of the liquid storage tank, and a working fluid return means that opens the on-off valve for a predetermined time after a predetermined time has elapsed after the engine has stopped. A heat pipe type car heating system. 2. The scope of the utility model registration claim, characterized in that the working fluid return means is constituted by a control device that outputs an open signal to the on-off valve based on input of an engine stop signal and a temperature signal of the heat receiving part of the heat pipe. The heat pipe type automobile heating device according to item 1. 3. The working fluid return means is constituted by a timer that outputs an open signal to the on-off valve for a predetermined time after a predetermined time elapses after the engine is stopped, as set forth in claim 1 of the utility model registration claim. Heat pipe type car heating device.