JP2000213358A - Internal combustion engine with combustion heater - Google Patents

Abstract

(57) [Summary] In an internal combustion engine provided with a combustion type heater and a supercharger, the intake air temperature is sufficiently increased by the combustion type heater. In an internal combustion engine having a combustion heater (22) for discharging combustion gas to an intake system of the internal combustion engine to raise the temperature of an engine-related element, and a supercharger for supercharging intake air from the intake system, When the combustion gas of the type heater is discharged to the intake system of the internal combustion engine, when the intake air temperature is lower than a predetermined temperature, the supercharge prohibiting means for prohibiting supercharging by the supercharger bypasses the turbine of the supercharger. Bypass 15 through which exhaust gas flows through the valve mechanism 1 and a valve mechanism 1 for opening and closing the turbine bypass
6, valve control means 8 for opening the valve mechanism when the intake air temperature is low
2 was provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an internal combustion engine provided with a combustion type heater for raising the temperature of engine-related elements and a supercharger for supercharging fresh air to the engine.

[0002]

2. Description of the Related Art In recent years, internal combustion engines have high thermal efficiencies, such as direct injection engines and diesel engines, for example, and the amount of excess heat discharged is small. Therefore, a combustion type heater is provided separately from the internal combustion engine to heat engine-related elements such as a heater core when the engine is started.

[0003] As an internal combustion engine equipped with a combustion type heater of this type, for example, an internal combustion engine described in Japanese Patent Application Laid-Open No. 62-75069 is known. This publication describes that the warm-up operation of the engine is completed within a short time by mixing the combustion gas of the combustor with fresh air and supplying the mixture to the engine.

[0004]

It is known to provide a supercharger for increasing the output of an internal combustion engine by supercharging fresh air supplied to the internal combustion engine.

When such a supercharger and the above-described combustion heater coexist, when the intake air temperature is low, the combustion gas from the combustion heater is discharged to the intake system and introduced into the internal combustion engine. Even if the fresh air is supercharged by the turbocharger at the same time, the cold gas is supercharged over the introduction of the combustion gas, and the original intention of introducing the high-temperature combustion gas from the combustion heater into the intake system. Will fade.

That is, there is a problem that the effect of increasing the intake air temperature by the combustion gas cannot be sufficiently obtained. SUMMARY OF THE INVENTION The present invention has been made in view of such a point, and an object of the present invention is to sufficiently increase the intake air temperature by a combustion heater when a combustion heater and a supercharger are provided.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is provided to increase the temperature of an engine-related element by heat obtained by burning fuel, and to convert the combustion gas of the fuel into an internal combustion engine. The following means are employed in an internal combustion engine having a combustion heater having a combustion gas discharge passage for discharging to an intake system of the engine and a supercharger for supercharging intake air from the intake system.

That is, when the combustion heater discharges combustion gas from the combustion gas discharge passage to the intake system of the internal combustion engine, if the intake air temperature is lower than a predetermined temperature, the supercharger for inhibiting supercharging by the supercharger is prohibited. Equipped with pay ban means.

According to this, when the intake air temperature is low, the combustion heater discharges the combustion gas from the combustion gas discharge passage to the intake system of the internal combustion engine, so that the combustion gas is mixed with the intake air to raise the intake air temperature. can do. Moreover, at this time, the supercharging prohibiting means prohibits supercharging by the supercharger,
There is no case where the low-temperature intake air is supercharged to reduce the temperature-raising effect of the combustion gas.

The supercharger includes a turbine provided in an exhaust passage of the engine and rotated by an exhaust gas flow flowing in the exhaust passage, and a turbine provided in an intake passage for introducing fresh air into the engine. And a compressor having a compressor that supercharges fresh air by rotating in conjunction with the compressor. At this time, the supercharging prohibiting means includes a turbine bypass which bypasses the turbine to flow exhaust gas, a valve mechanism for opening and closing the turbine bypass, and valve control means for opening the valve mechanism when the intake air temperature is low. Can be exemplified.

Further, it is preferable that an intake air temperature detecting means for detecting the intake air temperature is provided, and when the intake air temperature detected by the intake air temperature detecting means is equal to or lower than a predetermined temperature, the supercharging inhibiting means inhibits the supercharging. The detection of the intake air temperature may measure the intake air temperature at any part of the intake system, but the detection of the outside air temperature may be regarded as the intake air temperature.

When the prohibition of supercharging by the supercharging prohibiting means is released, when the cooling water temperature of the internal combustion engine becomes equal to or higher than a predetermined temperature, when the operation of the combustion type heater is stopped, the internal combustion engine becomes a high load operation. Sometimes. In order to detect such a state, an operating state determination unit may be provided.

Further, according to the present invention, as the combustion gas discharge passage of the combustion type heater, a first combustion gas discharge passage for discharging combustion gas to an exhaust system near the internal combustion engine, and the first combustion gas discharge passage. Selecting a second combustion gas discharge passage for discharging combustion gas to an intake system upstream of the passage, and one of the first combustion gas discharge passage and the second combustion gas discharge passage according to an operation state of the engine; Discharge passage selection means.

For example, the second combustion gas discharge passage is
It is connected to the intake system on the upstream side of the turbocharger. First
When the combustion gas discharge passage is selected, the combustion gas of the combustion heater can be fed into the internal combustion engine from a position close to the internal combustion engine in a high temperature state.
C and white smoke can be reduced.

When it is not desirable to mix high-temperature combustion gas, for example, after the warm-up operation has been completed, the combustion gas is fed into the intake system from the second combustion gas discharge passage to separate from the internal combustion engine. Since the combustion gas is supplied from the deviated portion, the temperature of the combustion gas decreases, and the influence on the internal combustion engine is reduced.

In the case where the second combustion gas discharge passage is provided with a cooling means for cooling the passing combustion gas, the combustion gas is cooled and fed, so that the influence of the temperature of the combustion gas can be reduced. More effective.

It is preferable that the combustion heater discharges combustion gas from the combustion gas discharge passage to an intake system of the internal combustion engine during a cold operation of the internal combustion engine. This is because, during cold operation, it is desired to supply high-temperature combustion gas to the internal combustion engine to reduce HC and white smoke and promote warm air. During such a cold operation and when the intake air temperature is lower than a predetermined temperature, the supercharging prohibiting means prohibits the supercharging by the supercharger, so that the cold intake air is supercharged and the combustion gas is discharged. Therefore, it is possible to avoid reducing the effect of increasing the temperature.

Note that the combustion type heater is a heater attached to the internal combustion engine separately from the internal combustion engine main body, and performs its own combustion without being affected by the combustion in the cylinder of the internal combustion engine main body at all. It emits gas. Since it is necessary to raise the temperature of the engine-related elements before the engine is started, it is provided separately from the internal combustion engine body.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an internal combustion engine according to the present invention will be described with reference to FIGS. FIG. 1 is a diagram showing a schematic configuration of an internal combustion engine according to the present embodiment.
The internal combustion engine shown in FIG. 1 is a multi-cylinder water-cooled diesel engine.

The diesel engine has an engine main body 1 having a water jacket containing engine cooling water, an intake device 2 for feeding air necessary for combustion into a plurality of cylinders of the engine main body 1, and an exhaust gas after combustion of the air-fuel mixture. It has an exhaust device 3 for releasing gas into the atmosphere, and a heater core 4 of a heating device for warming the interior of a vehicle equipped with an engine.

The intake device 2 includes an air cleaner 5 for filtering intake air, an air flow meter (not shown) for measuring a flow rate of intake air passing through the air cleaner 5, and a turbocharger as a supercharger for pumping the intake air. 6 and an intercooler 7 for cooling intake air whose temperature has been increased by heat generated when the compressor 6a compresses the intake air.
And an intake manifold 8 for sending intake air passing through the intercooler 7 to each cylinder of the engine body 1, and these are connected to each other by an intake pipe 9. Further, an intake throttle valve 11 is arranged between the intercooler 7 and the engine body 1.

The exhaust device 3 includes an exhaust manifold 12 connected to an exhaust port of the engine body 1,
The exhaust pipe 14 includes a turbine 6b of the turbocharger 6, an exhaust purification catalyst 13a for purifying exhaust gas, and a muffler 13b connected to the catalyst 13a. As the exhaust purification catalyst 13a, a selective reduction type lean NOx catalyst,
A lean NOx storage reduction catalyst can be exemplified.

The selective reduction type lean NOx catalyst is defined as an atmosphere containing excess oxygen (lean atmosphere) and a hydrocarbon (H
A catalyst that reduces or decomposes NOx in the presence of C), and examples thereof include a catalyst in which a transition metal such as Cu is ion-exchanged on zeolite and a catalyst in which a noble metal is supported on zeolite or alumina. In the selective reduction type lean NOx catalyst, the catalyst bed temperature is within a catalyst purification window (temperature range for activating the catalyst), the air-fuel ratio of the inflowing exhaust gas is a lean atmosphere, and HC, preferably hot If there is HC whose molecular size has been reduced by decomposition, a part of HC is partially oxidized to generate active species, and the active species reacts with NOx in exhaust gas to convert NOx into N ₂ , Reduce to H ₂ O, CO _2, etc.

The storage-reduction type lean NOx catalyst uses, for example, alumina as a carrier, and on the carrier, for example, an alkali metal such as potassium K, sodium Na, lithium Li or cesium Cs, or an alkaline earth such as barium Ba or calcium Ca. , Lanthanum La, and at least one selected from rare earths such as yttrium Y, and a noble metal such as platinum Pt. When the ratio of air and fuel (hydrocarbon) supplied to the engine intake passage and the exhaust passage upstream of the NOx catalyst is referred to as the air-fuel ratio of the exhaust gas flowing into the NOx catalyst, the NOx catalyst generates When the fuel ratio is lean, NOx is absorbed, and when the oxygen concentration in the inflowing exhaust gas decreases, the absorbed NOx is released.

The turbine 6b of the turbocharger 6 is provided on the exhaust pipe 14 upstream of the catalyst 13a. The turbine 6b bypasses the turbine 6b and connects the upstream and downstream sides of the exhaust pipe 14. Reference numeral 15 is provided as supercharging prohibition means. In this turbine bypass 15,
A wastegate valve 16 is provided as a valve mechanism for opening and closing the turbine bypass 15. The wastegate valve 16 is connected to an ECU 18 which is a computer for engine control, and is controlled to open and close according to a command from the ECU 18.

Further, as shown in FIG. 1, a heater branch pipe 31 is provided, which branches off from an intake pipe 9 connecting the air cleaner 5 and the compressor 6a of the turbocharger 6, and is a combustion air introduction path. The combustion type heater 22 is connected to the heater branch pipe 31.

The combustion heater 22 heats a heat medium (cooling water) by heat generated by burning fuel separately from the engine, and uses the heat medium as an engine-related element to form the heater core 4 or the engine body 1. And heat generated thereby heats these engine-related elements. Therefore, the heat medium (cooling water) is supplied from the combustion type heater 22 via the heater core 4 and the water jacket of the engine body 1.
The heat medium circulation path which circulates is provided.

As such a heat medium circulation path, the combustion type heater 22 is provided with cooling water for the engine.
2 is connected to a cooling water discharge passage 33 that guides the cooling water heated in the combustion type heater 22 to the engine body 1 via the heater core 4.

Here, a specific configuration of the combustion type heater 22 will be described with reference to FIG. Inside the combustion type heater 22, a heater internal cooling water passage 22a communicating with a cooling water introduction passage 32 and a cooling water discharge passage 33 is formed for flowing cooling water from the water jacket.

The heater internal cooling water passage 22a is arranged so as to circulate around a combustion chamber 22d formed inside the combustion type heater 22, and cooling water flowing through the heater internal cooling water passage 22a is supplied from the combustion chamber 22d. The temperature rises due to the heat.

The combustion chamber 22d includes a combustion cylinder 22b as a combustion source for generating a flame, and a cylindrical partition wall 22c that covers the combustion cylinder 22b to prevent the flame from leaking to the outside. In this way, the combustion cylinder 22b is
By covering with c, the combustion chamber 22d is defined in the partition wall 22c. The partition wall 22c is covered by the outer wall 24 of the combustion type heater 22. The partition 22
An annular gap is provided between c and the outer wall 24, and this gap functions as the above-described heater internal cooling water passage 22a.

The combustion type heater 22 has an air supply port 22e.
And an exhaust outlet 22f, and the air supply port 22e and the exhaust outlet 22f communicate with the combustion chamber 22d. The heater branch pipe 31 is connected to the air supply port 22e for introducing the intake air.
2 f is connected to the intake pipe 9 via a combustion gas discharge pipe (combustion gas discharge passage) 51. Therefore, the exhaust outlet 2
The combustion gas discharged from 2f is introduced into the intake pipe 9 and flows into the engine body 1.

The combustion gas discharge pipe 51 is connected to a first combustion gas connected between the intake throttle valve 11 of the intake pipe 9 and the intake manifold 8 so that the combustion gas flows directly into the intake manifold 8 of the engine body 1. Discharge pipe (1st
A second combustion gas discharge pipe (second combustion) connected to a position downstream of the connection of the heater branch pipe 31 in the intake pipe 9 and upstream of the compressor 6a of the turbocharger 6. (A gas discharge passage) 51b, and a first combustion gas discharge pipe 51a and a second combustion gas are provided at a branch point between the first combustion gas discharge pipe 51a and the second combustion gas discharge pipe 51b. An exhaust switching valve 61 is provided as a discharge passage selecting means for selecting any one of the discharge pipes 51b. Further, the second combustion gas discharge pipe 51b
Is provided with a water-cooled exhaust cooler 62 as cooling means for cooling the combustion gas flowing in the pipe.

Continuing the description of the combustion type heater 22, the fuel introduction passage 25 is connected to the combustion cylinder 22b so that a part of the fuel discharged from the fuel pump 16 is supplied to the combustion cylinder 22b. Has become. Further, a vaporizing glow plug (not shown) for vaporizing the fuel supplied through the fuel introduction passage 25 is provided in the combustion cylinder 22b.
And an ignition glow plug (not shown) for igniting the vaporized fuel. The vaporizing glow plug and the ignition glow plug may be shared by a single glow plug.

In the combustion type heater 22 configured as described above, the intake air flowing into the air supply port 22e from the heater branch pipe 31 is guided to the combustion chamber 22d, and is supplied to the combustion cylinder 22b through the fuel introduction passage 25. The fuel is vaporized by the vaporizing glow plug. Then, the intake air and the vaporized fuel are mixed to form an air-fuel mixture, and the air-fuel mixture is ignited by an ignition glow plug in the combustion chamber 22d and burns.

Further, a branch from the exhaust pipe 14 between the exhaust manifold 12 and the turbine 6b of the turbocharger 6 is connected to the intake pipe 9 between the intake throttle valve 11 and the intake manifold 8, and the exhaust gas is exhausted. An EGR pipe 71 is provided as an exhaust recirculation passage that guides the exhaust gas to the intake pipe 9 via the combustion type heater 22.

An EGR control valve 72 for adjusting the flow rate of exhaust gas is provided in the EGR pipe 71. Although not shown, the EGR control valve 72 is an electric control valve.
It is driven by a negative pressure from a vacuum pump via a vacuum regulating valve (EVRV). Said E
The duty ratio of the VRV is controlled by the ECU 18 according to the operating condition of the engine. The opening amount of the EGR control valve 72 changes depending on the magnitude of the negative pressure.

The ECU 18 receives signals such as an intake air temperature detected by an intake air temperature sensor, a cooling water temperature THW flowing through a water jacket of the internal combustion engine, an engine speed NE, an acceleration position Accp, a parking brake PB, and the like. As shown in FIG. 3, the operating state determining means 81 for determining the operating state from the values of these signals, the supercharging prohibition instructing means 82, and the switching valve control means 83 for switching the exhaust switching valve 61 are implemented on the ECU 18. Have been. The supercharging prohibition command means 82 is a valve control means for issuing a command to the wastegate valve 16 to open the valve 16 when the intake air temperature is equal to or lower than a predetermined temperature. Since a part of the gas bypasses the exhaust pipe 6b of the turbine portion and passes through the turbine bypass 15, the rotation of the turbine 6b is stopped.
Accordingly, the rotation of the compressor 6a also stops, and the supercharging of the intake stops. The switching valve control means 83 performs a cold operation of the engine based on the determination result of the operating state determination means 81,
Alternatively, when the intake air temperature is low, the switching valve 61 is instructed to select the first combustion gas discharge pipe 51a,
The combustion gas from the combustion heater 22 is directly fed into the intake manifold 8.

The combustion heater control means 84 for issuing an operation command / operation stop command to the combustion heater 22 based on the judgment result of the operation state judgment means 81, the EGR control valve 72
EG for duty-controlling the EVRV to control
The R control means 85 is also implemented on the ECU 18.

Next, an example of control of the internal combustion engine according to the present embodiment will be described. The control routine shown in FIG. 4 is repeatedly executed at predetermined time intervals. First, in step S10, the coolant temperature TW is taken into the ECU 18, and in step S20, the operating state determination means 81 determines whether or not the engine has just started from the coolant temperature based on the coolant temperature. It is determined whether or not the vehicle is cold. Here, it is determined whether or not the cooling water temperature TW is higher than, for example, 50 ° C. When the cooling water temperature is 50 ° C. or less, it is determined that the temperature is cold,
Proceeding to S30, the first combustion gas exhaust pipe 51a is selected by the exhaust switching valve 61 according to a command from the switching valve control unit 83, and the EGR control valve 72 is fully closed by the EGR control unit 85 in S40.

At this time, since the operation is a cold operation, an operation command is issued from the combustion heater control means 84 to the combustion heater 22, and the fuel is burned in the combustion heater to heat the cooling water. And the combustion type heater 22
From the first combustion gas discharge pipe 51a to the intake pipe 9
Is supplied together with fresh air into the cylinder of the engine body 1 via the Therefore, the intake air is warmed to reduce HC in the combustion chamber.

In S20, when the operating state determining means determines that the cooling water temperature TW is higher than, for example, 50 ° C.,
Proceeding to 50, the second combustion gas discharge pipe 51b is selected by the control of the exhaust switching valve 61 by the switching valve control means 83, so that the combustion gas from the combustion heater 22 is cooled by the water-cooled exhaust cooler 62. The air is exhausted to the intake pipe 9 on the upstream side of the compressor 6a.

The degree of opening control of the EGR control valve 72 varies depending on the operating state of the engine. However, as shown in FIG. 5, the control amount of the exhaust gas flow rate by the EGR control valve 72 depends on the fuel injection amount and the engine speed. It is calculated from the determined EGR duty map. This is the same as that used for known EGR control. As a result, as shown in FIG.
When the EGR duty increases, the EVRV 82 opens greatly, the negative pressure applied to the control valve 72 also increases, the EGR control valve 72 opens greatly, and the flow rate of the exhaust gas, that is, the EGR
% Increases.

The EGR control valve 72 is opened when the internal combustion engine is in a low or middle speed range, such as at low or medium speed, and the engine temperature rises. The EGR control valve 72 opens the exhaust gas from the exhaust system to the intake system through the EGR pipe 71. return. Note that the EGR device does not operate during a high-load operation range or during deceleration. When the EGR control valve 72 is opened during high load operation, the exhaust pressure in the exhaust pipe 14 decreases,
This may cause the rotation of the turbine 6b to decrease or cause black smoke to be generated.

The control of the EGR control valve 72 is realized by the ECU 18 executing a routine as shown in FIG. This control routine is a routine that is repeatedly executed at predetermined time intervals.

First, initialization is performed in S101, and in S102
The engine speed NE, the temperature of the cooling water flowing through the internal combustion engine, and the like are taken into the ECU 18. Next, in S103, the fuel injection amount is taken into the ECU 18. further,
In S104, the control duty ratio of the EVRV 82 is determined from the two-dimensional map determined by the engine speed × the fuel injection amount. When the control duty ratio of the EVRV 82 is determined, the opening of the EGR control valve 72 is determined by controlling the EVRV 82 based on the value.
5, the EGR%, that is, the combustion gas ratio is determined.

When the EGR control should not be performed, the EGR control valve 72 is closed, and the exhaust gas from the exhaust outlet 22f is not introduced into the intake pipe 9. During the cold operation, the combustion type heater 22 is operated as described above, and the combustion gas is introduced into the first combustion gas intake pipe 9 without being cooled. The following routine is executed so that supercharging by the compressor 6a of the charger 6 is not performed.

First, as shown in FIG. 8, it is determined in S201 whether or not the combustion type heater 22 is operating. When the combustion type heater 22 is not operating, the routine ends. Next, when the combustion type heater 22 is in operation, S
At 202, it is determined whether the intake air temperature is lower than a predetermined temperature. When the intake air temperature is not lower than the predetermined temperature, the routine is terminated with the waste gate valve 16 closed in S203, and when the intake air temperature is lower than the predetermined temperature, the supercharge prohibition command means 82 causes the waste gate valve 16 in S204.
And exhaust gas is discharged from the turbine bypass 15. Then, since the amount of exhaust gas passing through the exhaust pipe 14 of the turbine 6b is reduced, the turbine 6b does not rotate, and accordingly, the compressor 6a does not rotate.
The supercharging of the intake stops.

Since this routine is repeatedly executed at predetermined time intervals, when the intake air temperature becomes higher than the predetermined temperature,
In S203, the waste gate valve 16 is closed, and thereafter, the turbine 6b is rotated, and thereby, the supercharging of intake air is performed by the rotation of the compressor 6a.

This control is performed only during the cold operation, and after the warm-up operation is completed, this control is not performed, and the wastegate valve 16 is always closed so that the turbine can rotate. Good.

[0051]

According to the present invention, when the combustion gas is fed into the internal combustion engine by the combustion type heater, the operation of the supercharger is prohibited when the intake air temperature is low. It can be done effectively.

Therefore, when the intake air temperature rises when the intake air temperature is low, H
C and white smoke can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an embodiment of an internal combustion engine having a combustion heater according to the present invention.

FIG. 2 is a schematic sectional view of a combustion type heater.

FIG. 3 is a block diagram showing function realizing means realized on an ECU;

FIG. 4 is a diagram showing an exhaust switching valve control routine according to the embodiment;

FIG. 5 is an EGR duty map determined from a fuel injection amount and an engine speed.

FIG. 6 is a graph showing the relationship between EGR duty and EGR%.

FIG. 7 is a diagram showing an EGR control routine;

FIG. 8 is a diagram showing a control routine for opening and closing the turbine bypass.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Engine body 2 ... Intake device 3 ... Exhaust device 4 ... Heater core 5 ... Air cleaner 6 ... Turbocharger 6a ... Compressor 6b ... Turbocharger turbine 7 ... Intercooler 8 ... Intake manifold 9 ... Intake pipe 11 ... Intake throttle valve 12 ... Exhaust manifold 13a NOx catalyst 13b Muffler 14 Exhaust pipe 15 Turbine detour (supercharge prohibition means) 16 Valve mechanism (est gate valve) 18 ECU 22a Heater internal cooling water passage 22b Combustion cylinder 22c Partition wall 22d combustion chamber 22e air supply port 22f exhaust discharge port 24 outer wall 25 fuel introduction passage 31 heater branch pipe (combustion air introduction passage) 32 cooling water introduction passage 33 cooling water discharge passage 51 combustion Gas discharge pipe (combustion gas discharge passage) 51a ... first combustion gas discharge Pipe (first combustion gas discharge passage) 51b ... second combustion gas discharge pipe (second combustion gas discharge passage) 61 ... exhaust switching valve (exhaust passage selecting means) 71 ... EGR pipe (exhaust gas recirculation passage) 72 ... EGR control valve 81 ... Operating state determination means 82 ... Supercharging prohibition command means (valve control means) 83 ... Switching valve control means 84 ... Combustion heater control means 85 ... EGR control means

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Claims (6)

[Claims] 1. A combustion type fuel combustion system having a combustion gas discharge passage provided to raise the temperature of an engine-related element by heat obtained by burning fuel and discharging a combustion gas of the fuel to an intake system of an internal combustion engine. In an internal combustion engine having a heater and a supercharger for supercharging intake air from the intake system, when the combustion heater discharges combustion gas from the combustion gas discharge passage to an intake system of the internal combustion engine, an intake air temperature is predetermined. An internal combustion engine having a combustion heater, comprising: a supercharge prohibition unit that prohibits supercharging by the supercharger when the temperature is lower than a temperature. 2. The turbocharger is provided in an exhaust passage of an engine and is rotated by an exhaust gas flow flowing in the exhaust passage, and is provided in an intake passage for introducing fresh air into the engine and is interlocked with the turbine. A compressor that supercharges fresh air by rotating as described above, the supercharging prohibiting means includes a turbine bypass that flows exhaust gas around the turbine, and a valve mechanism that opens and closes the turbine bypass. 2. An internal combustion engine having a combustion heater according to claim 1, further comprising valve control means for opening a valve mechanism when the intake air temperature is low. 3. A first combustion gas discharge passage for discharging combustion gas to an exhaust system near an internal combustion engine as a combustion gas discharge passage of the combustion type heater, and an upstream of the first combustion gas discharge passage. A second combustion gas discharge passage for discharging combustion gas to an intake system; and a discharge passage selection means for selecting one of the first combustion gas discharge passage and the second combustion gas discharge passage according to an operation state of the engine. An internal combustion engine having the combustion heater according to claim 1, comprising: 4. The system according to claim 3, wherein the second combustion gas discharge passage is connected to an intake system upstream of a supercharger.
An internal combustion engine having the combustion-type heater described in the above. 5. An internal combustion engine having a combustion type heater according to claim 3, wherein said second combustion gas discharge passage has cooling means for cooling passing combustion gas. 6. The combustion type heater discharges combustion gas from the combustion gas discharge passage to an intake system of the internal combustion engine during a cold operation of the internal combustion engine. The internal combustion engine having a combustion heater according to any one of claims 1 to 5, wherein supercharging by the supercharger is prohibited when the intake air temperature is lower than a predetermined temperature.