JPH08156576A - Heating system for automobile - Google Patents

Abstract

PURPOSE: To improve the rising characteristics of a combustion type heater when the combustion type heater is employed in the heating system for an automobile. CONSTITUTION: Since an electric heater 17 is installed onto the upstream side section 16a of a combustion air introduction pipe 16, which passes through the inside of a path for heating air (in the figure as an example, a vent pipe 7 at the downstream side of a combustion type heater 1), when an electric heater 17 is energized so as to be heated, heat produced heats up combustion air to be fed to the combustion chamber 4 of the combustion type heater 1, and concurrently heats up heating air to be fed to a cabin. Therefore, when the combustion type heater 1 is driven, the electric heater 17 heats up heating air, concurrently by letting the heat of the electric heater 17 be given to heating air, the combustion type heater 1 is thereby prevented from being missed in ignition, its rising is accelerated, and exhaust air emission right after starting is thereby improved. Besides, when outside air is comparatively high in temperature, heating can be performed only by the electric heater.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating system for an automobile, and more particularly, to an electric vehicle which has a so-called "combustion type heater" which has a relatively low operating cost as a heat source and which does not have a heat source such as an internal combustion engine. The present invention also relates to a heating device suitable for being installed in.

[0002]

2. Description of the Related Art As described in U.S. Pat. No. 3,989,029 and U.S. Pat. No. 3,989,030, as an auxiliary heating device for an automobile, in addition to an internal combustion engine, a fuel is combusted to generate combustion heat exclusively. A so-called "combustion type heater" used for the purpose of heating a vehicle interior is known. When using a conventional combustion heater, even if the switch is turned on and started, the first several tens of seconds are spent for preheating the combustion chamber, so a large amount of fuel is supplied to the combustion chamber at the same time as starting and is effective. However, there is a problem that the heating does not start up normally. Further, in cold regions, the outside air temperature is low, which makes it difficult to preheat or evaporate the fuel before ignition, and the combustion heater may cause an ignition error.

Further, in a heating system for an electric vehicle,
Fuel is used because it is usually difficult to use the battery power directly as a heat source for the heating system because it is necessary to reduce the power consumption of the battery, which has a limited capacity to reduce the weight of the vehicle. Even though it has been found that it is advantageous to use a combustion heater, which has a low operating cost, for a heating device, the combustion heater is accompanied by the problem of exhaust gas like the internal combustion engine. There is a situation that is incompatible with the purpose of introducing an electric vehicle that is not equipped with, and there is a situation in which it is inappropriate to mount the combustion heater as it is on the electric vehicle.

[0004]

SUMMARY OF THE INVENTION The present invention addresses the above-mentioned problems in a conventional vehicle heating system and provides a fuel heater from the time of start-up while using a combustion heater as a heat source, which has a relatively low operating cost. It is an object of the present invention to provide a novel heating device which has good ignitability and quick start-up of heating and which is also suitable for mounting on an electric vehicle.

[0005]

As a means for solving the above problems, the present invention provides a combustion type heater having a combustion chamber for combusting a fuel to give heat to heating air, and the above combustion. A combustion air introducing pipe for supplying combustion air to the room, a heating means for heating the heating air to be introduced into the vehicle compartment by the combustion gas generated in the combustion chamber, and a heating air for the heating means. And a heating air passage means for guiding the heating air heated in the heating means into the passenger compartment, and the upstream side portion of the combustion air introduction pipe is provided with the heating air. An electric heater is attached to an upstream side portion of the combustion air introducing pipe passing through the inside of the passage means and passing through the inside of the passage means. To.

[0006]

Since the electric heater is attached to the upstream side of the combustion air introducing pipe passing through the inside of the heating air passage means, when the electric heater is energized to generate heat, the heat is generated by the combustion heater. While heating the combustion air supplied to the combustion chamber, it also heats the heating air supplied to the vehicle compartment. Therefore, when the combustion heater is started, the electric heater heats the heating air until the combustion heater operates effectively, and at the same time, the heat of the electric heater is applied to the combustion air to prevent the fuel before ignition. Preheat and promote evaporation to prevent the combustion heater from making a mistake in ignition. This promotes the rise of the combustion heater and improves the exhaust emission immediately after the combustion heater is started. When the temperature of the outside air is relatively high, the combustion heater can be stopped and heating can be performed only by the electric heater.

[0007]

FIG. 1 shows a first embodiment of a heating system for an automobile according to the present invention. The combustion heater 1 used in the heating device of this embodiment belongs to a type called a warm air type, and vaporizes the fuel supplied from the fuel tank 2 by the fuel pump 3 in the combustion chamber 4. Is heated by directly exchanging heat between the high-temperature combustion gas generated and the heating air flowing in the outer cylinder 6 in the heat exchanger 5 which is a "heating air heating means". The heating air is guided to the passenger compartment side by the ventilation pipe 7 which is a part of the "heating air passage means", and is heated by blowing it out into the passenger compartment from a blowout port such as a defroster, chest, or feet not shown. is there.

In FIG. 1, 8 is a combustion type heater 1.
A glow plug for preheating the fuel supplied in a part of the combustion chamber 4 to promote ignition by being energized by a battery to generate heat at the time of starting the engine, and 9 is a combustion chamber 4
Combustion air fan for sending combustion air to
Is a flame sensor for detecting that combustion of fuel is occurring in the combustion chamber 4, and 11 is formed between the outer surface of the heat exchanger 5 and the outer cylinder 6 so that the heating air is generated as described above. A flowing air gap, 12 is a heating air fan for pumping the heating air from the ventilation gap 11 to the ventilation pipe 7, and 13 is a part of the "heating air passage means".
2 shows an outside air introduction pipe for introducing outside air into 2.

An outside air temperature sensor 14 is attached to the outside air introduction pipe 13, and the detection signal thereof is input to an electronic control unit (ECU) 15 for controlling the combustion state together with the detection signal of the flame sensor 10 and the like, Thereby, the combustion state in the combustion chamber 4 is controlled. Therefore, although not shown in FIG. 1, the fuel pump 3, the glow plug 8, the combustion air fan 9, the heating air fan 1
2 etc. are also connected to it so as to be controlled by the electronic control unit 15.

Corresponding to the features of the present invention, in the heating apparatus of the first embodiment, the upstream side of the combustion air introducing pipe 16 for introducing combustion air into the combustion air fan 9 should be opened directly to the outside air. First, the upstream side portion 16a of the combustion air introducing pipe 16
Is supplied with air by passing through the heating air vent pipe 7 through which the heating air heated in the combustion heater 1 flows and communicating with the outside air. As a result, the heating air vent pipe 7 and the upstream side portion 16a of the combustion air introduction pipe 16 are heat exchangers (hereinafter generally referred to as HE) for heating the combustion air, which is one of the features of the present invention. ).

At least a part of the upstream side portion 16a of the combustion air introducing pipe 16 in the heating air ventilation pipe 7 is provided with, for example, one or a plurality of coil-shaped electric heaters 17 connected in series. They are connected to a battery (not shown) via a switch that is turned on and off by the electronic control unit 15. Therefore, the electric heater 17
When electric power is supplied from a battery or a generator by a switch that is closed by a command from the electronic control unit 15, the electric heater 17 generates heat and the combustion air introduction pipe 16
The combustion air flowing therein is heated, and at the same time, the heating air flowing in the heating air vent pipe 7 is also heated to simultaneously raise the temperature of those air. The combustion chamber 4
Exhaust gas discharged from, like the conventional combustion heater,
It is designed to be discharged into the outside air through the exhaust pipe 18.

Since the heating apparatus of the first embodiment is constructed in this way, first, even when heating is required, the outside air temperature is higher than the predetermined temperature Ta, the heating load is relatively small, and only the electric heater 17 is used. When it is possible to sufficiently heat the vehicle, the electronic control unit 15 operates only the electric heater 17 and the heating air fan 12 in order to suppress the exhaust emission. The outside air introduced by the heating air fan 12 (the inside air in the vehicle compartment can be introduced as a part or all of the outside air by providing a conventionally known passage switching means in an automobile) is the combustion heater 1.
The air passes through the outer cylinder 6 of the above, is heated in a portion of the heating air vent pipe 7 where the electric heater 17 is installed, and is directly supplied to the vehicle interior as heating air.

At this time, since the combustion air fan 9 is stopped, there is substantially no air flow in the combustion air introduction pipe 16, and almost all the heat of the electric heater 17 is passed through the heating air passage. It is given to the heating air into the passenger compartment passing through the trachea 7. In this case, as a specific numerical example of an automobile of a normal size, when the outside air temperature detected by the outside air temperature sensor 14 is 5 ° C., the required power consumption of the electric heater 17, that is, the amount of heat generation is For example, it is 2.5 kW.

When the outside air temperature is lower than the predetermined temperature Ta, the combustion type heater 1 is operated. In this case, the electric heater 17 is also operated at the same time. The reason is that, even if the combustion heater 1 is started, it is necessary to take a so-called preheating time for energizing the glow plug 8 to preheat the combustion chamber 4 for about 20 to 40 seconds to promote evaporation and ignition of fuel. Therefore, during this period, the air flowing through the heating air vent pipe 7 is heated by the electric heater 17 having an immediate temperature, and the rising delay of the combustion heater 1 is compensated. Further, during this period, the combustion air passing through the combustion air introduction pipe 16 is heated by the electrothermal heater 17, so that the ignitability of the fuel in the combustion chamber 4 of the combustion heater 1 is improved and the exhaust emission at the time of ignition is reduced. To do.

Then, when combustion is established in the combustion chamber 4 of the combustion type heater 1 and it is detected by the flame sensor 10, or when a predetermined short time has elapsed from that, it is judged that the combustion has become a steady combustion state. At this time, the electronic control unit 15 stops energizing the electric heater 17, but the combustion air supplied to the combustion chamber 4 of the combustion type heater 1 through the combustion air introduction pipe 16 is a heat exchanger. The HE is heated by the heating air that has passed through the heating air vent pipe 7 and has an increased temperature, so that a stable combustion state of the fuel can be maintained in the combustion chamber 4. In addition to shutting off the power supply to the electric heater 17, a temperature sensor (not shown) is provided in the heating air vent pipe 7 in addition to the output signal of the frame sensor 10 to sufficiently raise the temperature of the heating air flowing therethrough. It may be performed by the electronic control device 15 at the time.

2 (a) and 2 (b), the heating air vent pipe 7 and the upstream side portion 16a of the combustion air introduction pipe 16 are shown.
And a specific detailed structure of the heat exchanger HE, which is a feature of the present invention and further includes an electric heater 17. Reference numeral 19 is a fin radially provided outside the upstream portion 16a, which promotes heat exchange between the heating air heated by the combustion heater 1 and the combustion air supplied to the combustion heater 1. In addition, the heating of the combustion air by the electric heater 17 is also assisted.

FIG. 3 shows a heating system for an automobile as a second embodiment of the present invention. The feature of this embodiment is that the heat exchanger HE for heating the combustion air is one of the features of the present invention.
Is configured in the outside air introduction pipe 13. That is, the upstream side portion 16a of the combustion air introducing pipe 16 is inserted into the outside air introducing pipe 13 which is the upstream side of the combustion heater 1, and the electric heater 17 is attached thereto. Also in this embodiment, the heating air can be heated only by the electric heater 17 in a state where the outside air temperature is relatively high (heat loss increases to some extent), and the combustion air is electrically heated when the combustion heater 1 is started. Although the heater 17 can be preheated to accelerate the rising, if the electric power to the electric heater 17 is cut off when the steady combustion state is reached, the combustion air cannot be preheated thereafter.
The example is better.

The first and second embodiments exemplify a case where the present invention is applied to a hot air type heating device, but a third embodiment shown in FIG. 4 is a hot water type heating device according to the present invention. It is an example applied to a device. In the case of the hot water type, the combustion gas generated in the combustion type heater having the combustion chamber 4 and the fuel supply system which are substantially the same as those of the combustion type heater 1 is first of all water as a heat medium (generally referred to as liquid). The heating air supplied to the passenger compartment is heated by the hot water. That is, the heating is performed in two stages. As the "heating air heating means", a water jacket portion for heating hot water with combustion gas, a circulation path for hot water, a heater core for heating heating air with hot water, etc. Will be included. As described above, in the case of the hot water type, the heating air is indirectly heated by the combustion type heater, but there is an advantage that the degree of freedom in arranging each part constituting the heating device becomes high.

In the example of FIG. 4, a water jacket 20 for circulating water as a heat medium is formed around the combustion chamber 4 of the combustion heater 1'having a warm water structure. The heater core 22 in the air conditioning unit 21 is connected by reciprocating hot water passages 23 and 24 to form a series of circulation passages for hot water. According to the conventional technique, the hot water passage 23 is provided with the pressure cap 25 and the reserve tank 26 in series to adjust the amount and pressure of water in the circulation passage. A water pump 27 is inserted in the hot water passage 24 to forcibly circulate the hot water in the circulation passage.

In the air conditioning unit 21 shown in FIG. 4, 28 is an indoor blower, and 29 is a damper for switching the outside air and the inside air as the air introduced into the unit 21, or for adjusting the mixing ratio thereof. Indicates an air mix damper provided for adjusting the ratio of the air heated through the heater core 22 (heating air) and the air not heated by bypassing the heater core 22. ing. Further, 31 is a circulation path 23 or 2 of the hot water for detecting the temperature of the circulating hot water.
4 shows a water temperature sensor provided in a part of No. 4.

In the case of the third embodiment, the heat exchanger HE for heating the combustion air and the heating air, which is one of the features of the present invention, is provided in the combustion chamber 4 of the combustion heater 1 '. A combustion air introduction pipe 16 for supplying the air is provided so that the upstream side portion 16a passes across the inside of the air conditioning unit 21, and the upstream side portion 16a is provided with an electric heater 17.
It is configured by attaching.

Since the heating device of the third embodiment is constructed as shown in FIG. 4, the hot water heated in the water jacket 20 of the combustion type heater 1'is circulated in the hot water passages 23 and 24 so that the heater core 22 is moved. To heat. Air conditioning unit 21
Outside air or inside air is sucked into the inside by an indoor blower 28, and a part of the air flows through the heater core 22 depending on the position of the air mix damper 30. At that time, the heater core 22 heats the air into heating air, and the passenger compartment is heated. Will be sent to the outlet.

In this case, when the electric heater 17 is energized by a command from the electronic control unit 15, the combustion air supplied to the combustion heater 1'will flow in the air-conditioning unit 21 which is a substantially closed space. Combustion air introduction pipe 1 passing through
When flowing through the upstream side portion 16a of 6, the electric heater 17
Can be heated in a highly efficient state. Further, when the heating load is relatively small, the heating air flowing in the air conditioning unit 21 is directly heated by only the electric heater 17, or the electric heater 1'is activated when the combustion heater 1'is activated.
The combustion air can be heated by 7 and the heating air can be supplementarily heated. Therefore, it can be said that the third embodiment has substantially the same actions and effects as those of the above-described first or second embodiment.

[0024]

According to the present invention, a heating device using a combustion heater starts up faster, and preheating and evaporation of fuel before ignition is promoted even in cold regions when the outside air temperature is low and the combustion heater is used. It is possible to prevent the ignition error. Further, since the exhaust emission immediately after starting the combustion type heater can be improved, it is suitable for use as a heating device for an electric vehicle. In general, since the combustion type heater that uses fuel and has a low operating cost is used for the heating device, it is possible to achieve the effects such as being economical.

[Brief description of drawings]

FIG. 1 is a sectional view showing a heating device as a first embodiment of the present invention.

2A and 2B conceptually illustrate the structure of a heat exchanger, which is one of the features of the present invention, in which FIG. 2A is a longitudinal sectional view and FIG. 2B is a partial transverse sectional view.

FIG. 3 is a sectional view showing a heating device as a second embodiment of the present invention.

FIG. 4 is a sectional view showing a heating device as a third embodiment of the present invention.

[Explanation of symbols]

 1, 1 '... Combustion heater 4 ... Combustion chamber 5 ... Heat exchanger 6 ... Outer cylinder 7 ... Heating air vent pipe 8 ... Glow plug 9 ... Combustion air fan 10 ... Frame sensor 11 ... Ventilation gap 12 ... Heating Air fan 13 ... Outside air introduction pipe 14 ... Outside air temperature sensor 15 ... Electronic control device 16 ... Combustion air introduction pipe 16a ... Upstream side portion 17 ... Electric heater 19 ... Fin 20 ... Flue 21 ... Air conditioning unit 22 ... Heater core 23, 24 ... Warm water passage 28 ... Indoor blower 29 ... Damper 30 ... Air mix damper HE ... Heat exchanger

Claims (8)

[Claims] 1. A combustion type heater having a combustion chamber for burning fuel to give heat to heating air, a combustion air introduction pipe for supplying combustion air to the combustion chamber, and a combustion chamber introduction pipe. Heating means for heating the heating air by the combustion gas generated in the combustion chamber, and supplying the heating air to the heating means and guiding the heating air heated by the heating means into the vehicle interior. Heating air passage means, and the upstream side portion of the combustion air introducing pipe passes through the inside of the heating air passage means and also passes through the inside of the passage means. An electric heater is attached to an upstream side portion of the combustion air introducing pipe. 2. The upstream side portion of the combustion air introducing pipe,
2. The vehicle heating device according to claim 1, wherein the heating device is provided at a downstream side portion of the heating air heating means in the heating air passage means. 3. The upstream side portion of the combustion air introducing pipe,
The vehicle heating device according to claim 1, wherein the heating device is provided in an upstream side portion of the heating air heating means in the heating air passage means. 4. The combustion gas generated in the combustion chamber is configured to directly heat the heating air in the heating air heating means. The heating system for an automobile according to. 5. The combustion gas generated in the combustion chamber heats hot water in the heating air heating means, and the heated hot water heats the heating air, thereby indirectly heating the combustion gas. The vehicle heating device according to any one of claims 1 to 3, which is configured to heat the air for use. 6. The upstream side portion of the combustion air introducing pipe,
The vehicle heating device according to claim 2, further comprising a fin provided at a position where the fin passes through the inside of the heating air passage means. 7. In addition to the above configuration, a control device and an outside air temperature sensor are provided, and the control device operates only the electric heater when the detected value of the outside air temperature sensor is equal to or higher than a predetermined temperature, The heating system for an automobile according to claim 1, wherein the combustion heater is operated when the detected value of the outside air temperature sensor is equal to or lower than a predetermined temperature. 8. In addition to the above configuration, an ignition detection means in the combustion heater is provided, and the control device energizes the electric heater when the ignition detection means detects ignition in the combustion heater. The heating system for an automobile according to claim 7, which is stopped.