JPH0712089Y2 - Automotive heating system that uses exhaust heat - Google Patents

Description

[Detailed Description of the Invention] (Industrial field of application) A vehicle heating system utilizing exhaust heat according to the present invention is
By utilizing the principle of the heat pipe, the interior of the vehicle is heated by the heat of the exhaust gas discharged from the engine.

(Prior Art) A heating device that heats the interior of a vehicle by using exhaust heat heats up faster than a device that heats by using heat of cooling water (time required to obtain a feeling of heating). short)
Therefore, various structures have been studied so far, but as a heating system for automobiles that recovers exhaust heat using the principle of heat pipes and heats the interior of the vehicle,
-114806, 63-154312, and 63-181511 are known.

FIG. 2 shows the invention described in Japanese Utility Model Laid-Open No. 63-154312, which is shown in FIG. 2. As shown in FIG. The same applies to the following description.),
Briefly explained.

Reference numeral 1 denotes an exhaust pipe through which exhaust gas emitted from an automobile engine 7 is circulated. In the exhaust pipe 1, first and second exhaust passages 2 and 3 are provided in parallel with each other. A heater 4 for heating and evaporating a working fluid such as pure water is provided in the second exhaust flow path 3 therein, and one end of a steam delivery pipe 5 is connected to a steam outlet of the heater 4. is doing.

In the middle of the exhaust pipe 1, upstream of the first and second exhaust flow paths 2 and 3, the flow rate of the exhaust gas sent to the second exhaust flow path 3 in which the heater 4 is arranged is adjusted. Flow control door 6
Is provided so that the heating amount of the working fluid in the heater 4 can be freely adjusted.

On the other hand, a condenser 9 having a steam inlet connected to the other end of the steam delivery pipe 5 is arranged in the duct 8 through which the air for heating is circulated by the blower 13, and one end is connected to the outlet of the condenser 9. Then, on the way, reservoir 11 and sluice valve 12
The other end of the return pipe 10 provided in the above is communicated with the heater 4, and the working fluid condensed and liquefied in the condenser 9 is returned to the heater 4.

Reference numeral 14 is a controller for controlling the operation of an actuator 15 for driving the exhaust flow rate adjusting door 6, and a temperature sensor 16 for detecting the exhaust temperature and a temperature sensor for detecting the working fluid temperature in the heater 4. Based on the signals from 17 and 17, the operation of the actuator 15 is controlled to adjust the opening of the exhaust flow rate adjusting door 6.

When the interior of the vehicle is heated by the conventional vehicle heating system utilizing exhaust heat configured as described above, the exhaust flow rate control door 6 is switched as shown by the chain line in FIG. Open and operate the blower 13.

As a result, the working fluid existing in the heater 4 is evaporated and sent to the condenser 9 through the steam delivery pipe 5. The vapor of the working fluid in the condenser 9 is
A cycle in which heat is exchanged between the air blown by the blower 13 and the air flowing in the duct 8 to condense it, the condensed air is returned to the heater 4 through the return pipe 10, and evaporation is performed again is repeated. The air whose temperature has risen due to heat exchange in the duct 8 is blown into the vehicle interior through an appropriate outlet provided at the downstream end of the duct 8 and is used for heating the vehicle interior.

Exhaust flow control door 6 when the heating system is not used
Is switched to the state shown by the solid line in FIG. 2 and the sluice valve 12 is closed.

As a result, high-temperature exhaust gas is not sent to the heater 4, the working fluid remains stored in the liquid reservoir 11 and is not sent to the heater 4, and the temperature of the condenser 9 does not rise. Therefore, the temperature of the air flowing through the duct 8 does not rise.

(Problems to be Solved by the Invention) By the way, in the case of incorporating an automobile heating device configured as described above and utilizing exhaust heat into an actual automobile heating device, the following problems must be solved. There are issues that must be addressed.

That is, the extent to which the temperature of the air flowing in the duct 8 is increased by the condenser 9 is affected by the temperature of the working fluid flowing in the condenser 9, and the temperature of the working fluid flowing in the condenser 9 is It is affected by the amount of heat, which is the product of the temperature and the flow rate of the exhaust gas flowing in the passage 3.

However, in the case of the above-described conventional vehicle heating system that utilizes exhaust heat, the exhaust flow rate control door 6 is controlled only by the temperature of the exhaust gas flowing in the exhaust pipe 1 and the temperature of the working fluid generated in the heater 4. When the amount of exhaust gas flowing through the exhaust pipe 1 suddenly increases due to sudden acceleration of the vehicle because the so-called feedback control that adjusts the opening is performed,
Switching of the exhaust flow rate control door 6 cannot always be performed quickly (switching of the exhaust flow rate control door 6 cannot keep up with changes in the situation), and the temperature of the working fluid vapor sent from the heater 4 to the condenser 9 rises, The air temperature after passing through the condenser 9 becomes higher than desired.

The vehicle heating device utilizing exhaust heat of the present invention solves the above-mentioned inconvenience.

(Means for Solving the Problems) A vehicle heating device utilizing exhaust heat of the present invention is provided with a first and a second heaters provided in parallel with each other in the middle of an exhaust pipe through which exhaust gas emitted from an automobile engine is circulated. A second exhaust flow passage, a heater provided in the second exhaust flow passage, a steam delivery pipe whose one end is connected to a steam outlet of the heater, and upstream sides of the first and second exhaust flow passages. And an exhaust flow rate adjusting door that adjusts the flow rate of the exhaust gas that is sent to the second exhaust flow path, and is disposed in a duct that circulates heating air,
It is composed of a condenser having a vapor inlet connected to the other end of the vapor delivery pipe, and a return pipe having one end connected to the outlet of the condenser and returning the working fluid condensed and liquefied in the condenser to the heater.

Further, in the vehicle heating system utilizing the exhaust heat of the present invention, the signal from the temperature sensor for detecting the temperature of the exhaust gas before passing through the heater and the detector for detecting the operating state of the engine are used. A controller for calculating the heat quantity of the exhaust gas from the signal and adjusting the position of the exhaust flow rate adjusting door based on the calculated value is provided, and when the heat quantity of the exhaust gas discharged from the engine is large, the controller is If the exhaust flow rate control door is switched in the direction to reduce the proportion of the exhaust gas flowing to the second exhaust passage, and the heat quantity of the exhaust gas discharged from the engine is small, the proportion of the exhaust gas flowing to the second exhaust passage is increased. It is configured to switch the exhaust flow rate control door in the direction of turning on.

(Operation) In the case of the vehicle heating system utilizing the exhaust heat of the present invention configured as described above, when the controller has a small amount of heat of the exhaust gas discharged from the engine, If the exhaust flow rate control door is switched to increase the proportion of the exhaust gas flowing and the heat quantity of the exhaust gas discharged from the engine is low, the exhaust flow rate control door will increase the proportion of the exhaust gas flowing to the second exhaust passage. Since so-called feedforward control is performed, the amount of heating of the working fluid by the heater arranged in the second exhaust passage can always be maintained at the optimum value.

(Embodiment) Next, the present invention will be described in more detail with reference to the illustrated embodiment.

FIG. 1 is a schematic cross-sectional view showing a heating device for an automobile using exhaust heat of the present invention.

In FIG. 1, reference numeral 1 is an exhaust pipe through which exhaust gas emitted from an automobile engine is circulated.
The first and second exhaust flow paths 2 and 3 are provided in parallel with each other. A heater 4 for heating and evaporating a working fluid such as pure water is provided in the second exhaust flow path 3 therein, and one end of a steam delivery pipe 5 is connected to a steam outlet of the heater 4. Connected.

In the middle of the exhaust pipe 1, upstream of the first and second exhaust passages 2 and 3, the amount of exhaust sent to the second exhaust passage 3 in which a heater 4 is arranged is adjusted. A flow rate control door 6 is provided to freely control the heating amount of the working fluid in the heater 4. The opening degree of the exhaust flow rate adjusting door 6 can be adjusted by an actuator 15.
15 is controlled by a controller 18 described later.

On the other hand, a condenser 9 having a steam inlet connected to the other end of the steam delivery pipe 5 is arranged in the duct 8 through which the air for heating is circulated by the blower 13, and one end is connected to the outlet of the condenser 9. Then, on the way, reservoir 11 and sluice valve 12
The other end of the return pipe 10 provided with is connected to the heater 4 so that the working fluid condensed and liquefied in the condenser 9 is returned to the heater 4.

Further, a bypass passage 19 is provided in the duct 8 in parallel with the condenser 9, and air flowing through the bypass passage 19 and the condenser 9 is provided upstream of the bypass passage 19 and the condenser 9. Air mix door to adjust the proportion of
20 are provided.

As described above, the controller 18 for controlling the actuator 15 for driving the exhaust flow rate adjusting door 6 includes the temperature sensor 28 (as shown in the figure, for detecting the temperature of the exhaust gas before passing through the heater 4.
It may be provided in front of the exhaust flow rate adjusting door 6 or in front of the heater 4. ) And a signal from a detector 21 attached to a microcomputer or the like for controlling the operation of the engine. That is, the detector 21 reads a signal related to the flow rate of exhaust gas discharged from the engine (for example, a signal representing the engine speed) from the signal of the microcomputer or the like, and sends this signal to the controller 18.

Then, the controller 18 calculates the heat quantity of the exhaust gas based on the both signals, and issues a command to the actuator 15 according to the calculated value. That is, the controller 18 reduces the proportion of the exhaust gas flowing through the second exhaust passage 3 in which the heater 4 is arranged when the heat quantity (the product of the temperature and the flow rate) of the exhaust gas discharged from the engine is large. Therefore, when the exhaust flow rate adjusting door 6 is displaced in a direction approaching the solid line state of FIG. 1 and the heat quantity of the exhaust gas discharged from the engine is small, the proportion of the exhaust gas flowing in the second exhaust flow path 3 is increased. Therefore, the exhaust flow rate control door 6 is displaced in a direction approaching the chain line state in the figure.

In FIG. 1, reference numeral 22 is an inside / outside air switching door for switching between the inside air inlet 23 and the outside air inlet 24, and 25 is provided on the downstream side of the blower 13 so that the air flowing in the duct 8 is operated during operation. An evaporator for cooling, 26 is provided in series with the condenser 9, a heater core for heating air by utilizing heat of cooling water, 27 is a distribution chamber provided at an end portion on the downstream side of the duct 8, The air whose temperature is adjusted in the duct 8 to an appropriate temperature is blown into the vehicle compartment through an appropriate outlet out of a plurality of outlets provided in the distribution chamber 27.

The heater core 26 is used to warm the air in place of the condenser 9 or together with the condenser 9 after the temperature of the cooling water rises sufficiently after the operation of the automobile is started.

In the case of the vehicle heating system using the exhaust heat of the present invention configured as described above, the controller 18 performs the feed-forward control by switching the exhaust flow rate adjusting door 6 according to the heat amount of the exhaust, so that the heating is performed. Fluctuations in the amount and temperature of the working fluid vapor sent from the device 4 to the condenser 9 can be suppressed to a low level, and the temperature of the air blown from the outlet of the heating device can be stabilized.

That is, when the amount of heat of the exhaust gas discharged from the engine is small, the exhaust flow rate control door 6 is switched to increase the ratio of the exhaust gas flowing through the second exhaust passage 3 in which the heater 4 is arranged, When the amount of heat of the exhaust gas discharged is small, the exhaust flow rate adjusting door 6 is switched to increase the ratio of the exhaust gas flowing through the second exhaust flow path 3, so that it is related to the change in the amount of heat of the exhaust gas discharged from the engine. Instead, the heat quantity of the exhaust gas passing through the heater 4 arranged in the second exhaust flow path 3 is kept substantially constant, and the heating quantity of the working fluid by the exhaust gas can be always maintained at the optimum value. It will be possible.

(Effects of the Invention) The vehicle heating system using exhaust heat of the present invention is configured and operates as described above, but flows to the heater regardless of changes in the flow rate and temperature of the exhaust gas discharged from the engine. Since the amount of heat of exhaust gas is kept almost constant and the temperature and amount of working fluid vapor sent to the condenser are kept almost constant by feedforward control, the temperature change of the air blown from the heating device is kept to a minimum. Is possible.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing an automotive heating system using exhaust heat of the present invention, and FIG. 2 is a sectional view showing an example of a conventional automotive heating system using exhaust heat. 1: Exhaust pipe, 2: First exhaust flow passage, 3: Second exhaust flow passage, 4: Heater, 5: Steam delivery pipe, 6: Exhaust flow control door, 7: Automotive engine, 8: Duct , 9: condenser, 10: return tube, 1
1: reservoir, 12: gate valve, 13: blower, 14: controller, 15: actuator, 16, 17: temperature sensor, 18: controller, 19: bypass flow passage, 20: air mix door, 21: Detector, 22: inside / outside air switching door, 23: inside air intake, 24: outside air intake, 25: evaporator, 26: heater core, 27: distribution chamber, 28: temperature sensor.

Claims (1)

[Scope of utility model registration request] 1. A first exhaust path and a second exhaust path, which are provided in parallel with each other, in the middle of an exhaust pipe through which exhaust gas emitted from an automobile engine is circulated. A heater, a steam delivery pipe whose one end is connected to the steam outlet of this heater, and an upstream side of the first and second exhaust passages, which adjust the flow rate of the exhaust gas sent to the second exhaust passage. A condenser that has an exhaust flow rate control door and a duct that circulates air for heating, and has a steam inlet connected to the other end of the steam delivery pipe and one end connected to the outlet of this condenser to condense in the condenser. A liquefied working fluid, consisting of a return pipe for returning to the heater, in a vehicle heating system utilizing exhaust heat, a signal from a temperature sensor for detecting the temperature of exhaust gas before passing through the heater, An inspection to detect the operating state of the engine A controller that calculates the amount of heat of exhaust from the signal from the engine and adjusts the position of the exhaust flow rate adjustment door based on this calculated value is provided, and this controller is used when the amount of heat of exhaust discharged from the engine is large. Switches the exhaust flow rate control door in a direction to reduce the proportion of the exhaust gas flowing in the second exhaust flow passage, and when the heat quantity of the exhaust gas discharged from the engine is small, the exhaust gas flow in the second exhaust flow passage is changed. An automotive heating system using exhaust heat, characterized in that the exhaust flow rate control door is switched to increase the ratio.