JPS6319536Y2 - - Google Patents

Description

[Detailed description of the invention] This invention purifies the exhaust gas by re-burning the unburned components in the engine exhaust using a catalyst.
The present invention relates to an improvement in an exhaust heat recovery device that efficiently absorbs and recovers the thermal energy of exhaust gas, which has become even hotter due to re-combustion, into a liquid such as water.

An example of an exhaust heat recovery device is one that recovers exhaust heat by flowing a heat exchange liquid directly around a catalyst cylinder that houses a catalyst inside.
In these systems, even when the engine is started, the catalyst cylinder is cooled from the surrounding area by the liquid used for regular heat exchange, so it takes a considerable amount of time for the catalyst to reach a high enough temperature to work properly, and during that time the exhaust gas remains untreated. There is a problem with it being released.

Therefore, it is possible to shorten the temperature rise time of the catalyst by forming an adiabatic space between the catalyst cylinder and the heat exchange liquid, but in this case, the catalyst becomes too hot during operation, and the catalyst is not supported. Durability was a problem because the components burned out early and the catalyst rattled and broke due to engine vibration.

This invention was proposed to solve the above-mentioned drawbacks, and it forms an adiabatic chamber between the catalyst cylinder and the heat exchange liquid to raise the temperature of the catalyst in a short time and quickly recycle the exhaust gas. In addition to enabling combustion processing, heat is radiated through an intermediate heat conductor to prevent burnout of the catalyst support and improve its durability, and the cooling chamber and heat exchanger are interposed in separate cooling channels. At the same time, when the temperature reaches a predetermined temperature, cooling water is sent to a cooling waterway with a heat exchanger interposed therebetween, thereby making it possible to efficiently recover the thermal energy of the exhaust gas.

Embodiments of the present invention will be described below with reference to the drawings.

Fig. 1 is a schematic diagram of a heat pump system using an engine as a power source and a heat source.A two-stroke engine 1 drives a refrigerant compressor 3 in a cooling system 2, and uses engine cooling water for heating and hot water supply. It is guided to the hot water storage tank 4 for heat exchange,
In addition, the engine exhaust is re-combusted in the catalyst tube 5, and the engine cooling water is guided to the heat exchanger R assembled in the catalyst tube 5 to recover the exhaust heat, and the exhaust gas is transferred to the muffler M. The sound is silenced and then released to the outside.

FIG. 2 shows details of the exhaust heat recovery device 6 and the heat exchange type catalyst cylinder 5, in which the catalyst cylinder main body 7 is divided into three bottomed cylinders, an inner cylinder 8, a middle cylinder 9, and an outer cylinder 10. The inner cylinder 8 has an exhaust inlet 11 at its bottom and a catalyst chamber 12 inside.
and an exhaust outlet 13 are formed. Two catalysts 14 are provided in the catalyst chamber 12 so as to partition the catalyst chamber 12 via a catalyst support 15, and a rectifier plate 17 formed of a perforated plate is provided between the catalysts 14 and the exhaust inlet 11.
is provided.

This inner tube 8 is inserted into a heat insulating chamber 16 formed inside the middle tube 9, and is supported by an intermediate heat conductor 18 so as to form a heat insulating space around it.

This intermediate heat conductor 18 is formed in the shape of a crank, and has a contact piece 18a at one end in fixed contact with the bottom of the inner cylinder 8 and an outer surface portion 8a of a portion where the catalyst 14 is provided, and a contact piece at the other end. The inner tube 8 is fixed to the inner tube 9 by bringing the piece 18b into contact with the inner surface 9a of the inner tube 9.

In addition, when the temperature of the catalyst 14 rises abnormally, this intermediate heat conductor 18 transfers high heat to the middle cylinder 9 via the catalyst support 15 and dissipates the heat to cool the catalyst 14 and prevent the temperature of the catalyst 14 from rising abnormally. This prevents the catalyst support 15 from burning out.

A box-shaped exhaust outlet 19 is opened toward the exhaust inlet 11 in the heat insulating chamber 16 between the bottom of the middle cylinder 9 and the bottom of the inner cylinder 8. It is supported by the upper end of a support tube 20 which is fixed by passing through the cylinder 10 and the middle cylinder 9, and an exhaust conduit 21 is inserted inside the support tube 20.

The exhaust pipe 21 includes an exhaust pipe 22 and an exhaust port 23.
It is connected to the combustion chamber 24 via.

A cooling chamber 25 is formed between the inner cylinder 9 and the outer cylinder 10 that covers it, and the cooling water of the engine 1 flows through the cooling chamber 25 when the temperature of the cooling water inside the cooling chamber 25 becomes high. ing.

That is, a cooling water inlet 26 and a cooling water outlet 27 are formed in the lower part near the exhaust outlet 13 and the upper part of the bottom side of the outer cylinder 10, respectively, and a temperature-sensitive valve is provided inside the mouth pipe part 28 forming the cooling water outlet 27. 29 is provided, and this temperature-sensitive valve 29 opens the cooling water outlet 27 when the cooling water in the cooling chamber 25 reaches a high temperature.

In this way, when the cooling water outlet 27 opens, the cooling water flows into the cooling chamber 25 from the engine cooling water channel W ₁ formed to circulate engine cooling water between the hot water tank 4 and the engine 1, and the catalyst cooling water channel W ₃
Configure.

Further, a temperature sensor temperature detection means 30 is provided on the upper surface of the outer cylinder 10 near the exhaust outlet 13 so as to pass through the cooling chamber 25, and a temperature sensing portion 30a at the tip thereof is provided.
is located near the intermediate heat conductor 18 of the inner cylinder 8 and detects the operation of the catalyst 14.

When this temperature sensor 30 detects a high temperature due to the operation of the catalyst 14, the control valve 31 in _the heat exchanger cooling waterway _W4 branched from the engine cooling waterway W1
Open it to allow water to flow to heat exchanger R, which will be described later.

The cooling water that has flowed into the catalyst cooling waterway _W3 exits from the cooling water outlet 27 formed in the outer cylinder 10, and the cooling water that has flowed into the heat exchanger cooling waterway _W4 flows into the heat exchanger R. After exiting from a discharge port 36, which will be described later, formed in , each water joins a cooling water channel W ₂ and heads toward the hot water storage tank 4 .

These inner cylinder 8, middle cylinder 9, and outer cylinder 10 are assembled by fastening the flange 32 formed on the exhaust outlet 13 side with the flange 33 of the heat exchanger R using bolts 34. is assembled.

Heat exchanger R receives cooling water from engine 1 through inlet 35.
A pair of head tanks 39 and 40 connected by a group of thin tubes 38 for heat exchange are housed inside a jacket-shaped heat exchange case 37 that is introduced from the exhaust port and flows out from the exhaust port 36. An exhaust gas introduction pipe 41 is connected to the flange base plate 42 and an exhaust pipe 43 is extended from the discharge side head tank 40 to the outside.

The operation of the exhaust heat recovery device 6 configured as above will be explained next.

First, when the exhaust heat recovery device 6 is cold, such as when the engine 1 is started, the cooling water in the outer cylinder 10 is drained from the cooling water in the cooling chamber 25 because the cooling water outlet 27 is blocked by the temperature-sensitive valve 29. Since the catalyst 14 is insulated from the cooling water in the heat insulating chamber 16, the temperature rises quickly and the exhaust gas is immediately re-combusted.

In this way, when the catalyst 14 works and the temperature reaches a high temperature, the temperature sensor 30 detects this and opens the control valve 31 that closes the cooling water inlet 35 of the heat exchanger R to allow water to flow into the heat exchanger R. , absorbs exhaust heat and radiates it in the hot water storage tank 4.

Next, when the catalyst 14 and the heat insulating chamber 16 reach a high temperature during operation of the engine 1, the heat insulating chamber 16 is prevented from becoming abnormally high temperature by the cooling water in the cooling chamber 25 formed around the heat insulating chamber 16, and the catalyst 14 is connected to the cooling chamber 25 via the catalyst support 15 and the intermediate heat conductor 18.
Since the heat is radiated to the cooling water, the catalyst support 15 is prevented from becoming abnormally high temperature and burning out.

In this way, when the heat insulation chamber 16 and the catalyst 14 are cooled and the cooling water in the cooling chamber 25 reaches a high temperature, the temperature-sensitive valve 29 of the cooling water outlet 27 opens and the cooling water in the cooling chamber 25 comes out from the cooling water outlet 27. Discharge port 3 of heat exchanger R
Together with the cooling water discharged from the hot water tank 6, the water is sent to the hot water storage tank 4 via the cooling waterway _W2 , where heat is radiated and heat exchanged.

The present invention is configured and operates as described above, and thus has the following effects.

In other words, when the temperature of the catalyst is low, such as during a cold start of the engine, the heat insulating chamber formed around the inner cylinder prevents heat dissipation from the catalyst, and the catalyst quickly rises to its reaction temperature, enabling the exhaust gas to be quickly re-combusted after the engine is started.

Additionally, when the catalyst is at high temperature, such as when the engine is running, the engine cooling water flowing into the cooling chamber cools the catalyst support via the heat conductor, so the catalyst support may burn out due to the abnormally high heat of the catalyst. This prevents the catalyst from rattling and breaking due to engine vibration, increasing its durability.

In addition, since the catalyst cooling channel with a cooling chamber and the heat exchanger cooling channel with a heat exchanger are provided separately, a large amount of heat is generated by providing an insulation chamber between the cooling chamber and the catalyst chamber. Apart from the catalyst cooling channel, which is difficult to obtain energy from, it is possible to recover the thermal energy of the engine exhaust only from the heat exchanger cooling channel, which can obtain a large amount of thermal energy from the heat exchanger. Cooling water is sent to the heat exchanger cooling waterway after the high-temperature engine exhaust passes through the heat exchanger using the temperature detection means located nearby, which improves the efficiency of recovering thermal energy from the engine exhaust. Since the thermal energy dissipated from the catalyst is also recovered from the catalyst cooling channel, the recovery efficiency of the exhaust heat recovery device becomes even higher.

[Brief explanation of the drawing]

The figures show an embodiment of the present invention; FIG. 1 is a schematic diagram of a heat pump system using an engine as a power source and a heat source, and FIG. 2 is a longitudinal sectional view of a heat exchange type muffler. DESCRIPTION OF SYMBOLS 1...Engine, 8...Inner cylinder, 8a...Outer surface part of 8, 9...Middle cylinder, 9a...Inner surface part of 9, 1
0... Outer cylinder, 11... Exhaust inlet, 12... Catalyst chamber, 13... Exhaust outlet, 14... Catalyst, 15...
Catalyst support, 16...Insulating chamber, 18...Intermediate heat conductor, 23...Exhaust port, 24...Combustion chamber, 2
5...Cooling chamber, R...Heat exchanger, _W3 ...Catalyst cooling waterway, _W4 ...Heat exchanger cooling waterway.

Claims (1)

[Scope of utility model registration request] The inner cylinder 8, the middle cylinder 9, and the outer cylinder 10 are inserted three times inside and outside, and a catalyst chamber 12 is formed in the inner cylinder 8, and a heat insulation chamber 1 is formed in the middle cylinder 9.
6. A cooling chamber 25 is formed in the outer cylinder 10, and a catalyst chamber 1 is formed inside the outer cylinder 10.
The exhaust inlet 11 of the engine 1 is connected to the combustion chamber 24 of the engine 1 via the exhaust port 23, and the exhaust outlet 1 of the catalyst chamber 12 is
3 are connected to the heat exchanger R, the cooling chamber 25 is interposed in the middle of the catalyst cooling waterway _W3 , the heat exchanger R is interposed in the middle of the heat exchanger cooling waterway _W4 , and the catalyst 14 is placed in the catalyst chamber 12. The catalyst 14 is supported on the inner surface of the inner cylinder 8 via the catalyst support 15, and the outer surface portion 8 of the inner cylinder 8 at the location where the catalyst support 15 is disposed.
an intermediate thermal conductor 18 is disposed between the intermediate thermal conductor 18 and the inner surface portion 9a of the middle cylinder 9, and a temperature sensing section 30a of the temperature sensing means 30 is disposed near the intermediate thermal conductor 18. An exhaust heat recovery device for an engine, characterized in that the control valve 31, which closes the inlet side of the heat exchanger cooling waterway _W4 , is opened based on the detection of a temperature above a predetermined value.