FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
[See section 10, rule 13]
“ENGINE EXHAUST HEAT RECOVERY SYSTEM”
NAME AND ADDRESS OF THE APPLICANT:
TATA MOTORS LIMITED, an Indian company having its registered office at Bombay house, 24 Homi Mody Street, Hutatma Chowk, Mumbai 400 001, Maharashtra, INDIA.
Nationality: Indian
The following specification particularly describes the disclosure and the manner in which it is to be performed.

TECHNICAL FIELD
The present disclosure generally relates to an exhaust system of automotive vehicles, and more particularly, to an exhaust muffler for utilizing exhaust heat of the automotive vehicle.
BACKGROUND OF THE DISCLOSURE
Various types of exhaust muffler, having different configurations and working principles, are used for exhaust noise attenuation. The size (volume) and weight of the exhaust muffler affects the packaging and handling of the muffler. Cost effectiveness and environment friendliness are among the other deciding factors of muffler design.
Discussing now the systems for heating or cooling of the cabin of the vehicle, water heater and combustion heater type heating system are frequently seen in vehicles. Combustion type heaters are typically applicable for very low ambient conditions where occupants require constant heat, even when vehicle is at idle condition (i.e. - engine not working). On the other hand, in water heater type heating system, engine coolant is circulated through heater whose circuit is parallel to engine external cooling circuit.
There are vehicles that employ vapor compression refrigeration system (VCRS). This system is quite simple and required less numbers of components but its operation cost is higher. This is so because it typically consumes at least 40 kW of power (work) from the engine. This is high grade energy. This adversely affects the performance, particularly the average (KMPL) of the vehicle. Further, this type of refrigeration system (VCRS) generally creates more noise and vibration because there are more rotating components.
OBJECTS OF THE DISCLOSURE
The objective of the present disclosure is to provide a reliable and simple system for engine exhaust heat recovery.
Another object of the present disclosure is to provide an exhaust muffler which can recover heat from exhaust gas for heating, ventilation and air conditioning purpose, which can also reduce noise of exhaust.

Another object of the present disclosure is to provide an effective solution of space constrains for both HVAC and exhaust systems of the vehicle.
Another object of present disclosure is to provide a dual functional exhaust muffler which is of less weight as compared with conventional exhaust mufflers.
Yet another object of present disclosure is to provide an exhaust muffler which is robust and which can be manufactured easily.
Further objects and features of the disclosure will become apparent from the following detailed description when considered in conjunction with the drawings.
SUMMARY OF THE DISCLOSURE
An embodiment of the present disclosure relates to an engine exhaust heat recovery system for an automobile having an exhaust muffler connected to an engine, the exhaust muffler comprising: an elongated tubular shell having a front cover and a rear cover opposite to a front cover, a plurality of chambers defined within the tubular shell by at least one baffle; an inlet pipe connected to the front cover such that a perforated end portion is positioned in the tubular shell; an outlet pipe carried by the rear cover, the outlet pipe having a perforated end portion covered with absorptive material, and an end portion opposite to the perforated end portion positioned out of the elongated tubular shell; a heat exchange pipe passing through the front cover and the rear cover of the elongated tubular shell;
In an embodiment of the disclosure an engine exhaust heat recovery system is claimed, wherein the tubular shell having first, second and third baffles disposed in spaced apart, to define a chamber within the tubular shell between each baffle and its respective front and rear cover, interconnected in fluid communication.
In an embodiment of the disclosure an engine exhaust heat recovery system is claimed, wherein an intermediate pipe carried by a second baffle such that a perforated end portion thereof is positioned in the second chamber formed.

In an embodiment of the disclosure an engine exhaust heat recovery system is claimed, the heat exchange pipe includes a plurality of heat exchange fins provided on a peripheral surface thereof.
In an embodiment of the disclosure an engine exhaust heat recovery system is claimed, wherein the plurality of heat exchange fins provided on a peripheral surface of the heat exchange pipe are in a region within the first chamber.
In an embodiment of the disclosure an engine exhaust heat recovery system is claimed, wherein each of the first baffle and the third baffle include a perforated portion.
In an embodiment of the disclosure an engine exhaust heat recovery system is claimed, wherein each of the elongated tubular shell, the inlet pipe, intermediate pipe, outlet pipe and the heat exchange second pipe are mutually parallel.
In an embodiment of the disclosure an engine exhaust heat recovery system is claimed, wherein a first end of the heat exchange pipe is connected to a blower supplying air, and a second end supplies heated air towards the cabin.
In an embodiment of the disclosure an engine exhaust heat recovery system is claimed, wherein a first end of the heat exchange pipe receives liquid water through a pump.
In an embodiment of the disclosure an engine exhaust heat recovery system is claimed, wherein the pump is driven by the engine.
In an embodiment of the disclosure an engine exhaust heat recovery system is claimed, wherein the second end of the heat exchange pipe is connected to a generator of a vapor absorption refrigeration system for providing air conditioning to the vehicle.
The proposed Exhaust muffler is basically a combination or hybrid type muffler which has twin role. It is an effective muffler which attenuates the noise of exhaust as per the requirement without violating recommended backpressure limit with lesser weight than existing. Same time it helps to recover waste heat of exhaust for HVAC purpose. It is a four chamber muffler. First two is reactive or reflective type. Last one is absorptive cum reactive type where third chamber is resnorative type. As mentioned this muffler works

as heat exchanger & it is basically, a counter-flow, air-to-air type heat exchanger. To achieve good heat recovery, flow pattern is made differently inside the muffler in comparison with conventional muffler. This flow pattern simultaneously helps to achieve good noise reduction performance.
The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
The novel features and characteristic of the disclosure are set forth in the appended claims. The disclosure itself, however, as well as a preferred mode of use, further objectives and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying figures. One or more embodiments are now described, by way of example only, with reference to the accompanying figures wherein like reference numerals represent like elements and in which:
FIG. 1 illustrates a perspective view of an exhaust muffler of an engine exhaust heat recovery system, in accordance with an embodiment of the present disclosure.
FIG. 2 illustrates a perspective cut-away view of the exhaust muffler of the engine exhaust heat recovery system of FIG. 1, in accordance with an embodiment of the present disclosure.
FIG. 3 illustrates a perspective view of a heat exchange pipe of the exhaust muffler of an engine exhaust heat recovery system of FIG. 1, in accordance with an embodiment of the present disclosure.
FIG. 4 side views of fins of the heat exchange pipe of the exhaust muffler of FIG. 3, in accordance with an embodiment of the present disclosure.

FIG. 5 illustrates a schematic diagram of the engine exhaust heat recovery system, in accordance with an embodiment of the present disclosure.
FIG. 6 illustrates a schematic diagram of the engine exhaust heat recovery system, in accordance with another embodiment of the present disclosure.
The figures depict embodiments of the disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.
DETAILED DESCRIPTION OF THE DISCLOSURE
The foregoing has broadly outlined the features and technical advantages of the present disclosure in order that the detailed description of the disclosure that follows may be better understood. Additional features and advantages of the disclosure will be described hereinafter which form the subject of the claims of the disclosure. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present disclosure. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the disclosure as set forth in the appended claims. The novel features which are believed to be characteristic of the disclosure, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present disclosure. It will be readily understood that the aspects of the present disclosure, as generally described herein, and illustrated in the figures, can be arranged, substituted, combined, and designed in a wide variety of different configurations, all of which are explicitly contemplated and make part of this disclosure. Referring now to the drawings wherein the showings are for the purpose of illustrating a preferred embodiment of the disclosure only, and not for the purpose of limiting the same.

FIG. 1 illustrates a perspective view of an exhaust muffler 100 of an engine exhaust heat recovery system 200. The exhaust muffler 100 for an automobile (not shown) includes a shell 102. The shell 102, as illustrated, is of an elongated tubular configuration. The elongated tubular shell 102 has a front cover 104 and a rear cover 106 opposite to a front cover 104, such that the elongated tubular shell 102 connects the front cover 104 and the rear cover 106. As per one embodiment of the present disclosure, the front cover 104 may be similar to the rear cover 106. Further, the elongated tubular shell 102, the front cover 104 and the rear cover 106 may be composed of a ferrous material of thickness of about 1 to 2 millimeter. A plurality of chambers (C1, C2, C3, and C4) defined by baffles disposed in spaced apart (114,122,124) within the tubular shell, between each baffle and its respective front and rear cover. The adjacent chambers are interconnected in fluid communications through holes/ perforations in the baffles.
Each of the front cover 104 and the rear cover 106 have a pair of holes. A heat exchange pipe 108 (best shown in FIG. 3) passes through a hole of the front cover 104 and a hole on the rear cover 106 of the elongated tubular shell 102. The heat exchange pipe 108 is made up of a material that facilitates heat transfer. In order to further increase the heat transfer, as best shown in FIG. 3, the heat exchange pipe 108 includes a plurality of heat exchanging fins 109. More specifically, the plurality of heat exchanging fins 109 are provided on the peripheral surface of the heat exchange pipe 108. In one embodiment of the present disclosure, the plurality of heat exchanging fins 109 are provided on a portion on the peripheral surface of the heat exchange pipe 108. Such portion on the peripheral surface of the heat exchange pipe 108 may be towards the front cover 104. Each fin of the plurality of heat exchanging fins 109 may have a predetermined profile.
FIG. 4 illustrates a few exemplary profiles, such as circular, circular perforated, and gear shaped profiles, of the heat exchanging fins 109. Each of such profiles of the heat exchanger fins 109 increases the area of contact of the heat exchanger fins 109. In one embodiment, both the heat exchange pipe 108 and the plurality of heat exchanger fins 109 have a thickness of about 1.5 to 3 millimeter.

Referring again to FIG. 1, the exhaust muffler 100 further includes an inlet pipe 110 connected to a second hole of the front cover 104. It would herein be apparent to those skilled in the art; a free end of the inlet pipe 110 is connected to an exhaust pipe EP (marked in FIG. 5 and 6) from the internal combustion engine ENG. Thus, the exhaust gases that enter through the inlet pipe 110 are heated because of the combustion in the internal combustion engine ENG.
The inlet pipe 110 has a perforated end portion 112. The perforated end portion 112 is positioned within a first chamber C1. As best shown in FIG. 2, the first chamber C1 is formed between the front cover 104 and a first baffle 114. As per one embodiment of the present disclosure, the plurality of heat exchanging fins 109 of the heat exchange pipe 108, are in a region within the first chamber C1. When exhaust gases from internal combustion engine enter the first chamber C1, heat transfer takes place between the exhaust gases and the heat exchange pipe 108 (also with the fins thereon).
The first baffle 114 has a portion without perforations 116, and a perforated portion 118. The portion without perforations 116 is in alignment with the inlet pipe 110. The perforated portion 118 is positioned below the portion without perforations 116, and it allows the exhaust gases in the first chamber to pass therethrough. Further, the heat exchanging pipe 108 also passes through the perforated portion 118.
The exhaust muffler 100 further includes an intermediate pipe 120. The intermediate pipe 120 is carried by a second baffle 122 such that a perforated end portion 123 of the intermediate pipe 120 is positioned within a second chamber C2 formed by the first baffle 114 and the second baffle 122. The second baffle 122 includes an opening (not numbered) for holding the intermediate pipe 120, and another opening for the heat exchanging pipe 108. Other than the said openings (not numbered) the second baffle 122 is without any perforations, unlike the first baffle 114. Therefore, all of the exhaust gasses in the second chamber C2 pass through the intermediate pipe 120 to reach a third chamber C3. The third chamber C3 is formed within the elongated tubular shell 102 between the second baffle 122 and a third baffle 124. The third baffle 124 is offset to the second baffle 122. The fourth chamber C4 is formed within the elongated tubular shell

102 between the third baffle 124 and the rear cover 106. As per the embodiment described herein, the first baffle 114 is similar in configuration to the third baffle 124 having a portion without perforations and a perforated portion.
The exhaust muffler 100 furthermore includes an outlet pipe 126. The outlet pipe 126 is carried by the rear cover 106. The outlet pipe 126 has a perforated end portion 128. The outlet pipe 126 is covered with absorptive material, such as glass or ceramic wool material. Absorptive material occupies 50% of the fourth chamber. Cell baffle is also provided at the proximity of the end portion. The perforated end portion 128 carrying the glass wool material is positioned within the fourth chamber C4. The exhaust gasses from the third chamber pass through this forth chamber C4 and get exited through the outlet pipe 126. As stated earlier, the heat exchange pipe 108 also passed through the rear cover 106.
As illustrated in figures each of the elongated tubular shell 102, the inlet pipe 110, the intermediate pipe 120, the outlet pipe 126, and the heat exchange pipe 108 may be mutually parallel. In one embodiment of the present disclosure, the elongated tubular shell 102, the inlet pipe 110, the outlet pipe 126, and the intermediate pipe 120 are along a single longitudinal axis of the elongated tubular shell 102. Each of the elongated tubular shell 102, the inlet pipe 110, the intermediate pipe 120, the outlet pipe 126, and the heat exchange pipe 108 may be made of CEW or ERW material of thickness about 1 to 2 mm.
The exhaust muffler 100 of the present disclosure is proposed for replacement of existing muffler and concentrates on multi functionality, weight, cost effectiveness and environment friendliness. First two chambers work as reactive / reflective chamber. Last chamber works as an absorptive cum reactive chamber and the third chamber works as resonarate-tive type. All pipes are straight type & there is no critical cutting & welding as in existing systems (Helps to ensure easy manufacturability & cost reduction). All perforation holes on inlet pipe, intermediate pipe and outlet pipe are of same size (diameter). Instead of using double shell with ceramic blanket in sandwich pattern,

single shell with higher thickness is used for reduction of shell noise. It helps in reduction of weight, cost and improves productivity.
FIG. 5 illustrates another embodiment of the engine exhaust heat recovery system 200. The engine exhaust heat recovery system 200 in this embodiment utilizes the exhaust muffler 200 for automobile cabin heating purposes. A first end portion 202 of the heat exchange pipe 108 receives cool atmospheric air. A blower 204 may be employed for supplying the air. The cool atmospheric air flows through the heat exchange pipe 108. Simultaneously, the engine 212, through turbocharger (TC) 214, exhaust brake (EB) 216 and exhaust pipe (EP) 218, supplies heated exhaust gasses to the exhaust muffler 100.
During such passage of the cool atmospheric air, the atmospheric air undergoes heat exchange because of cross-flow (counter flow) heat transfer with exhaust gasses. Thus produced hot air, flows out of the heat exchange pipe 106 through a second end 206 thereof, and through a flow control valve 208 (FCV) goes to the vehicle cabin 210. The exhaust muffler 100, thus, helps in reduction of exhaust noise inline to recover the waste heat of exhaust system for cab / cabin heating or air conditioning purpose.
FIG. 6 illustrates yet another embodiment of the engine exhaust heat recovery system 300. The engine exhaust heat recovery system 300, in this embodiment utilizes the exhaust muffler 100 for vehicle air conditioning. A pump (P), powered by the engine (ENG), supplies water (LW) from the first end portion 304 to the second end portion 306 of the heat exchange pipe 108. The water during passage through the heat exchange pipe 106 gets heated, again because of heat exchange thereof with the exhaust gases. The water resultantly becomes a mixture of heated water and water vapor. Such mixture of heated water and water vapor is supplied to a vapor absorptive refrigeration system. Following are the abbreviations used in FIG. 6 TC Turbo Charger, EB Exhaust Brake, EM Exhaust muffler, EP Exhaust Pipe, TP Tail Pipe, COM Compressor, B Blower, CA Cold air, HA Hot Air, V Water Valve, FCV Flow Control Valve, THS Thermostat, WP Water Pump, WH Water Heater, RAD Radiator, A Absorber, C Condenser, D Dryer, E Evaporator, G Generator, P Pump, WT Water Tank, WV Water Vapor, LW Liquid Water, EVR Refrigerant Expansion Valve, EVS Solution Expansion Valve , SHE

Solution Heat exchanger, TSB Temperature Sensing Bulb, Tr Temp at cabin, Tc Temp at condenser, Ta Temp at absorber, Te Temp at evaporator, Q Heat Regeneration, Qa Heat rejection at Absorber, Qc Heat Rejection at Condenser, Qe Heat Absorption at Evaporator, Qg Heat Absorption at Generator, Qw Heat recovered by heat exchanger from Exhaust gases, Wc Work Input for Compressor, and Wp Work Input for Pump.
The vehicle air condition system works on VARS (Vapor Absorption Refrigeration System) is used instead of popular VCRS for air conditioning system. In this aspect, the proposed dual functional exhaust muffler also helps to make an alternative air conditioning system based on VARS. The exhaust muffler also works as heat exchanger which recovers required amount of heat from exhaust system to run generator of VARS based air conditioning system.
The foregoing description provides specific embodiments of the present disclosure. It should be appreciated that these embodiment are described for purpose of illustration only, and that numerous other alterations and modifications may be practiced by those skilled in the art without departing from the spirit and scope of the disclosure. It is intended that all such modifications and alterations be included insofar as they come within the scope of the disclosure as claimed or the equivalents thereof.

Referral Numerals Description
100 Exhaust muffler
200/300 Engine exhaust heat recovery system
102 Elongated tubular configuration
104 Front cover
106 Rear cover
108 Heat exchange pipe

109
Plurality of heat exchanging fins
110 Inlet pipe
112 Perforated end portion
114 First baffle
116 Portion without perforations
118 Perforated portion
120 Intermediate pipe
122 Second baffle
124 Third baffle
126 Outlet pipe
128 Perforated end portion
202 First end portion
204 Blower
206 Second end portion
208 Flow control valve (FCV)
210 Vehicle cabin
212 Engine
214 Turbocharger
216 Exhaust brake

218
Exhaust pipe
302 Pump (P)
304 First end portion of exhaust muffler

We claim:
1. An engine exhaust heat recovery system (200) for an automobile having an
exhaust muffler (100) connected to an engine (212), the exhaust muffler (100)
comprising:
an elongated tubular shell (102) having a front cover (104) and a rear cover (106) opposite to a front cover (104),
a plurality of chambers (C1, C2, C3 and C4) defined within the tubular shell (102) by at least one baffle;
an inlet pipe (110) connected to the front cover (104) such that a perforated end portion (112) is positioned in the tubular shell (102);
an outlet pipe (126) carried by the rear cover (106), the outlet pipe (126) having a perforated end portion (128) covered with absorptive material, and an end portion opposite to the perforated end portion positioned out of the elongated tubular shell (202);
a heat exchange pipe (108) passing through the chambers (C1, C2, C3 and C4) defined within the elongated tubular shell (102).
2. The engine exhaust heat recovery system (200) as claimed in claim 1, wherein the
tubular shell (102) having first, second and third baffles (114, 122 and 124)
disposed is spaced apart, to define a chamber within the tubular shell (102)
between each baffle and its respective front and rear cover (104 and 106),
interconnected in fluid communication.
3 The engine exhaust heat recovery system (200) as claimed in claim 2, wherein an intermediate pipe (120) carried by a second baffle (122) such that, a perforated end portion (112) thereof is positioned in the second chamber (C2) formed.

4. The engine exhaust heat recovery system (200) as claimed in claim 1, wherein the heat exchange pipe (108) includes a plurality of heat exchange fins (109) provided on a peripheral surface thereof.
5. The engine exhaust heat recover system (200) as claimed in any one of the preceding claims, wherein the plurality of heat exchange fins (109) provided on a peripheral surface of the heat exchange pipe (108) are in a region within the first chamber (C1).
6. The engine exhaust heat recovery system (200) as claimed in claim 2, wherein each of the first baffle (114) and the third baffle (124) includes a perforated portion.
7. The engine exhaust heat recovery system (200) as claimed in any one of the preceding claim, wherein each of the elongated tubular shell (102), the inlet pipe (110), intermediate pipe (120), outlet pipe (126), and the heat exchange second pipe are mutually parallel.
8. The engine exhaust heat recovery system (200) as claimed in any one of the preceding claims, wherein a first end of the heat exchange pipe is connected to a blower supplying air, and a second end supplies heated air towards the cabin (210).
9. The engine exhaust heat recovery system (200) as claimed in any one of the preceding claims, wherein a first end of the heat exchange pipe (108) receives liquid water through a pump (302).
10. The engine exhaust heat recovery system (200) as claimed in claim 9, wherein the pump (302) is driven by the engine (212).

11. The engines heat recovery system as claimed in claim 9, wherein the second end of the heat exchange pipe (108) is connected to a generator of a vapor absorption refrigeration system for providing air conditioning to the vehicle.