DESC:Field of the invention:

The present invention relates in general, to field energy utilization and more particularly, to various methods of recovery of heat from engines of automobiles during testing.

Background of the invention:

The engines when manufactured for use are being tested in 21 different test beds. In a large sized automobile manufacturing company, around 800 engines are tested in a day. During engine testing, diesel is used for testing engine.

During engine testing, heat is available from at least three different sources which is not being utilized further and is wasted. Specifically, the energy generated from burning 1 Lt of diesel is as
=Mf * Cv ( Mf- Mass of Fuel – 0.832 Kg , Cv- Calorific Value 44.8 MJ / Kg )
= 0.832 * 44.8
= 38.6 MJ equivalent to 10.6 KWH.
Out of this energy generated 35 to 45 % is utilized for actual application as mobility and rest of energy is lost due to different reason like friction, exhaust and the like.

In exhaust system, around 35 % energy is wasted through hot exhaust gases. Out of 38.6 MJ or 10.6 KWH, energy wasting through exhaust is 35 % which equal to around 13.5 MJ or 3.71 KWH

The at least three sources of heat during testing of engine includes,
1. Heat available in form of hot gas at engine and test bed exhaust;
2. Heat available in form of hot water i.e. water circulated through engine during engine testing; and
3. Heat available in form of hot water i.e. residual water remains inside engine after engine testing.

Accordingly, there exists a need to provide a system and method which utilizes the heat available during testing of engine.

Object of the invention:

An object of the present invention is to use to utilize heat available during testing of engine.

Summary of the invention:
The present invention provides an exhaust heat harnessing system for manufacturing applications. The exhaust heat harnessing system includes a modified exhaust system pipe line for harnessing heat energy generated during automobile engine testing operations in the form of hot gases and hot water along with residual water. The exhaust heat harnessing system comprises of an automobile engine, a heat exchanger disposed in parallel communication with an exhaust of the automobile engine, a first water tank disposed in parallel communication with the heat exchanger, and a second water tank for collecting and storing the hot water recovered during automobile engine testing operation.
The heat exchanger is adapted for receiving hot gases from the exhaust of the automobile engine. The first water tank is connected to the heat exchanger for supplying continuous supply of cold water to the heat exchanger. Heat transfer between the hot gases and the cold water within the heat exchanger results into formation of hot water by transfer of heat from the hot gases to the cold water. The hot water generated and recovered during testing operation of the automobile engine gets collected within the second water tank connected thereto.
Testing of the automobile engine when performed using hot water also discharges hot water. In this case, some amount of the residual water is left behind within the automobile engine after completion of testing thereof using hot water. The system is adapted for recovering the residual water by purging pressurized air, particularly 2 bar pressurized air, from the automobile engine. The residual water thus recovered is passed through a residual water train connected to the automobile engine for transferring the recovered residual water within the second water tank connected thereto.
The hot water recovered during testing of the automobile engine is further used for different manufacturing applications. The second water tank is further connected to a washing machine for supplying the hot water thereto. Particularly, the second water tank is in communication with the washing machine through a heat exchanger disposed therebetween. The heat exchanger is adapted for transfer of heat between coolant media discharged from the washing machine and the hot water circulated from the second water tank to the washing machine resulting into transformation of coolant media to hot coolant media that gets circulated through the washing machine. The hot water thus looses heat to transform into cold water that gets collected back into the second water tank.

Brief description of the drawings:

Other features as well as the advantages of the invention will be clear from the following description.

In the appended drawings:
FIG. 1 to 8 provides various schematic drawings of prior art systems and systems of the present invention which utilizes heat available during testing of engine, in accordance with the present invention.

Detailed description of the embodiments:

For a thorough understanding of the present invention, reference is to be made to the following detailed description, including the appended claims, in connection with the above-described drawings. Although the present invention is described in connection with exemplary embodiments, the present invention is not intended to be limited to the specific forms set forth herein. It is understood that various omissions and substitutions of equivalents are contemplated as circumstances may suggest or render expedient, but these are intended to cover the application or implementation without departing from the spirit or scope of the claims of the present invention. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.

The present invention provides an exhaust heat harnessing system for manufacturing applications system (hereinafter ‘the system). The system includes a modified exhaust system pipe line. Specifically, a heat exchanger (80) is provided in parallel with the engine exhaust and cold water is circulated through the heat exchanger (80) from a first water tank (40) connected thereto to recover heat from exhaust and hot water stored in second water tank (60) for further use.

Figure 1 shows an engine exhaust system of the prior art, connected to test bed exhaust system and hot gasses around 110 Degree temperature exhausted to atmosphere, wherein Figure 2 shows the heat exchanger (80) provided in parallel to exhaust system and cold water circulated through it by the first water tank (40) connected to the heat exchanger (80) to recover heat.

In another aspect, the present invention provides a method and system for heat recovery from hot water during engine testing. Specifically, during engine testing, water is circulated through the engine from centralized water system. For proper performance of engine during testing, water temperature is maintain between 80 to 90 degree temperatures.
In this embodiment, from centralized water system, water is circulated through the engine and hot water from the engine is being cooled again from cooling tower (cooled water is required for Dynometer of test beds). Figure 3 shows the drawings showings supply of cooled water to the Dynometer. Specifically, figure 4 shows modified test beds water system pipe line, in accordance with the present invention. The engine out let pipe connected to second water tank (60) instead of centralized water system tank as in prior art and hot water from the engine is collected in the second water tank (60). The hot water is again used for two purpose i.e.
1. Some part of collected hot water used for engine testing
2. Some part of hot water heat recovered & used for other application.

In yet another aspect of the present invention, the present invention provides a system and method for heat recovery from residual water inside engine after engine testing. Generally, approximately 2 Ltr of water with temperature of 60 to 70 degree remains inside engine after testing after engine testing. In prior art method, these water is drained manually through manual valve and through gutter its collected at effluent treatment plant (ETP ) and after being treating used for other application as shown in figure 5. But in this, process heat of water not being used.

To use heat of water not, in this embodiment, the test beds pipe lines modified, in accordance with the present invention. The air circuit is prepared such that after engine testing, 2 bar pressure air is purged in engine and residual water inside test beds being collected in the second water tank (60) through modified pipe line as shown in figure 6. In this way, in the present invention, heat in form of hot water is collected from 3 different sources i.e. from engine exhaust, water during engine testing and from residual water after engine testing

Reuse of Hot water Collected at Main tank
Around 3000 Ltr of hot water with temperature of 80 to 90 degree collected in main tank from 10 test beds. The hot water is circulated towards washing machine through special pipe line (Around 350 M). At the washing machine, the hot water is circulated through one more heat exchanger (80) through which washing coolant media also circulated to heat coolant through heat transfer principle. Figure 7 shows the figure depicting reuse of hot water.

Washing media of the prior art, which earlier was being heated by electrical heaters and consuming around 171 Unit / Day for 1 machine. Now with collecting heat in form of hot water and being used for washing coolant media through heat exchanger (80) we will be able to save @ 171 Unit / day per machine
Further, the electrical consumption of washing machine electrical heaters will not reduce by 70 %. In this way, the wasted heat being utilized properly again through heat recovery principle. This helps to reduce electrical power consumption of washing Machines and reduce carbon foot prints also. The advantages of Reuse of hot water collected at main tank are as follows
1. Reduction of washing machine power consumption by 70 % .
2. Saving of total 514 Unit / day for 3 washing machine
3. Saving of Rs 11.94 / annum by reducing electrical consumption
4. Saving of 2 Lt of fresh water due to water draining & re-sue again
5. Reduction of test bed cycle time from 3 to 6 min by re-use of hot water instead of cold water & reducing pre-heating cycle time
Following chart illustrates Power Consumption Details of Washing Machines
Power Consumption Details of Washing Machines
Washing Details of Machine Shop Total Load of Machine in KWH for 2 Shift Heater load 35 % in KWH & ) 70 % loading
Washing Machine 1- Block Washing 700 171.5
Washing Machine 2- Head Washing 700 171.5
Washing Machine 3- Block Washing 700 171.5
Total kwh 2100 514.5
Annual costing ( Rs 8 / Unit for 290days) 48.72 11.94
Figure 8 shows process diagram of the exhaust heat harnessing system for manufacturing applications in accordance with the present invention.

Advantages of the invention

1. The system is cost effective being in house design & implementation .
2. The system is novel wherein heat from engine testing being utilized through heat recovery project.
3. The system is one step towards sustainability by reducing carbon foot print
4. Heat generated during engine testing being utilized again through heat recovery project & used for washing machines coolant media.
5. Reduction in washing machine electrical power consumption by 70 %

The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the present invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the present invention and its practical application, and to thereby enable others skilled in the art to best utilize the present invention and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omissions and substitutions of equivalents are contemplated as circumstances may suggest or render expedient, but such omissions and substitutions are intended to cover the application or implementation without departing from the spirit or scope of the claims of the present invention.
,CLAIMS:We Claim:

1. An exhaust heat harnessing system for manufacturing applications, the exhaust heat harnessing system being used for harnessing heat energy generated during testing of an automobile engine using water and diesel, the heat energy generated in form of hot water after circulation of water through the automobile engine leaving behind a residual water inside the automobile engine after testing thereof, and in form of hot gases by burning of the diesel during testing of the automobile engine, the exhaust heat harnessing system comprising of:
an automobile engine;
a heat exchanger (80) disposed in parallel communication with an exhaust of the automobile engine for receiving hot gases exhausted therefrom, the heat exchanger (80) adapted for recovering heat from the hot gases thereby forming hot water therefrom;
a first water tank (40) disposed in parallel communication with the heat exchanger (80) for continuously supplying cold water thereto, wherein the cold water circulated through the heat exchanger (80) is adapted for recovering heat from the hot gases present therein to form hot water therefrom by heat transfer between the hot gases and the cold water within the heat exchanger (80); and
a second water tank (60) connected to the automobile engine for collecting and storing the hot water recovered therefrom after testing thereof,
wherein the residual water left inside the automobile engine after testing is recovered by purging pressurized air therefrom such that the residual water gets collected in the second water tank (60) connected to the automobile engine for further use for manufacturing applications.

2. The exhaust heat harnessing system as claimed in claim 1, wherein the residual water is recovered by purging 2 bar pressurized air within the automobile engine.
3. The exhaust heat harnessing system as claimed in claim 1 further comprising a dynometer connected to the second water tank (60) for receiving hot water stored therein.

4. The exhaust heat harnessing system as claimed in claim 1, wherein the second water tank (60) is further connected to a washing machine for supplying the hot water thereto.

5. The exhaust heat harnessing system as claimed in claim 4, wherein the second water tank (60) is connected to the washing machine through a heat exchanger (80) disposed therebetween for transfer of heat between coolant media discharged from the washing machine and the hot water circulated from the second water tank (60) to the washing machine such that the coolant media gets transformed to hot coolant media that gets circulated through the washing machine whereas the hot water gets transformed to cold water after heat transfer that gets collected back into the second water tank (60).