Description:FORM 2
THE PATENTS ACT 1970
(39 of 1970)
&
THE PATENTS RULES, 2003

COMPLETE SPECIFICATION
(See section 10 and rule 13)

HEAT RECOVERY SYSTEM;

MAHINDRA & MAHINDRA LIMITED, A COMPANY REGISTERED UNDER THE INDIAN COMPANIES ACT, 1913, HAVING ADDRESS AT MAHINDRA & MAHINDRA LTD., MAHINDRA RESEARCH VALLEY. MAHINDRA WORLD CITY, PLOT NO.41/1, ANJUR P.O., CHENGALPATTU, KANCHIPURAM DISTRICT, TAMILNADU – 603004, INDIA

THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE NATURE OF THIS INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED

FIELD OF THE INVENTION:
The present invention relates to a heat recovery system for cooling of a vehicle part.
BACKGROUND OF THE INVENTION:
Generally, the body part of a vehicle from a body shop come into a paint shop for painting purpose. In the paint shop, the body parts are painted as per requirement. The paint is applied to the body parts for aesthetic look and/or corrosion resistance. The paint shop consists of an air supply unit, a baking oven, an underbody and sealer system, a painting robot, a paint mix room, and the like. For heat treatment in the baking oven, the body parts are transported through in the baking oven by a conveyor. The baking oven is sub-divided into an entrance, a heating-up zone, a holding zone, an exit zone, and a cooling zone.
Once the body parts are heated in the baking zone, the body parts are transferred to the cooling zone. Cooling of the body parts are mandatory as other operations need to be carried out immediately on the body parts. Another reason for cooling down the body parts is to prevent heat radiation to the surroundings.
Conventionally, the cooling zone includes an air supply unit to supply conditioned air (22⁰C to 25⁰C and 65% Relative Humidity to 75% Relative Humidity). In winter, due to cold and dry climatic conditions, the air supply unit utilized more fuel to maintain the operating temperature of the fresh air. Further, to maintain the relative humidity of the fresh air as per requirement, the humidification of the fresh air further reduces the temperature of the fresh air which ultimately increases fuel consumption to maintain the required air quality.
Therefore, there is a requirement of an improved system to overcome at least one of the above-mentioned problems.
SUMMARY OF THE INVENTION:
The object of the present invention is to design a system to solve the previously discussed problems.
According to the present invention, a heat recovery system of a cooling zone for a paint shop for cooling a vehicle part. The heat recovery system includes at least one exhaust fan to exhaust a hot air from the cooling zone to an atmosphere. The heat recovery system also includes at least one supply fan to supply a fresh air into the cooling zone from the atmosphere. The heat recovery system further includes an air supply unit. The air supply unit includes at least one heat exchanger to recover heat from the hot air. The heat exchanger includes air to water heat exchanger. The air supply unit also includes an enclosure adapted at the supply fan having a prefilter section to filter dust particles in the fresh air, a burner section for maintaining a predefined temperature of the filter fresh air, and a humidifier to sprinkle the hot water from the heat exchanger into the fresh air thereby providing a conditioned air to the supply fan at threshold temperature range and at threshold relative humidity range.
According to the present invention, the air supply unit provides the conditioned air between the threshold temperature range of 22⁰C to 25⁰C.
According to the present invention, the air supply unit provides the conditioned air between the threshold relative humidity range of 65% to 75%.
According to the present invention, the air supply unit includes at least one water tank to store water.
According to the present invention, the water is circulated from the water tank to the heat exchanger through the pump to pre-heated the water.
According to the present invention, the heat recovery system includes an automatic mode and a recirculation mode.
According to the present invention, in the automatic mode, a supply of the fresh air is controlled with respect to a temperature gradient of the hot air and the fresh air.
According to the present invention, in the automatic mode, the supply of the fresh air through the supply fan is controlled by a variable frequency drive (VFD) of the supply fan using one or more feedback temperature sensors disposed at inlet and outlet of the fresh air.
According to the present invention, in the automatic mode, the heat recovery system works automatically with the help of automation and controlled programmable logic controller (PLC).
According to the present invention, in the recirculation mode, a humidifier used the pre-heated water to maintain threshold relative humidity range of the fresh air.
BRIEF DESCRIPTION OF THE DRAWINGS:
FIG. 1 illustrates a schematic view of a heat recovery system in an automatic mode, according to an embodiment of the present disclosure; and
FIG. 2 illustrates a schematic view of a heat recovery system in a recirculation mode, according to an embodiment of the present disclosure.

DETAILED DESCRIPTION OF THE INVENTION
Preferred embodiments, of the present disclosure, will now be described along the best mode of operation with reference to the accompanying drawing.
Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or the like parts. Wherever possible, corresponding, or similar reference numbers will be used throughout the drawings to refer to the same or corresponding parts.
The terminology used, in the present disclosure, is only for the purpose of explaining a particular embodiment and such terminology shall not be considered to limit the scope of the present disclosure. As used in the present disclosure, the forms “a,” “an,” and “the” may be intended to include the plural forms as well, unless the context clearly suggests otherwise. The terms “comprises,” “comprising,” “including,” and “having,” are open ended transitional phrases and therefore specify the presence of stated elements, units and/or components, but do not forbid the presence or addition of one or more other elements, components, and/or groups thereof.
The terms first, second, third, etc., should not be construed to limit the scope of the present disclosure as the aforementioned terms may be only used to distinguish one element, component or region from another component, or section. Terms such as first, second, third etc., when used herein do not imply a specific sequence or order unless clearly suggested by the present disclosure.
FIGS. 1 and 2 illustrate a schematic view of a heat recovery system (100) of a cooling zone for a paint shop for cooling a vehicle part (102). The heat recovery system (100) is disposed above an oven cooling zone (104) proximate an exit of an oven (106) where heating of the vehicle part (102) takes place. The heat recovery system (100) includes at least one exhaust fan (108) to exhaust a hot air from the cooling zone to an atmosphere. The heat recovery system (100) may include any type and number of exhaust fan (108) without limiting the scope of the present invention. The exhaust fan (108) is disposed on a roof of the oven cooling zone (104) proximate the exit of the oven (106). The vehicle parts (102) exiting from the oven (106) have temperature ranging between 160°C to 200 °C. The hot vehicle parts (102) transmit heat to the surrounding which is exhausted with the help of exhaust fan (108).
The heat recovery system (100) also includes at least one supply fan (110) to supply a fresh air into the cooling zone from the atmosphere. The heat recovery system (100) may include any type and number of supply fan (110) without limiting the scope of the present invention. The supply fan (110) is disposed on the roof of the oven cooling zone (104) opposite to the exhaust fan (108). The fresh air relatively cooler than the exhaust air which is supplied in the oven cooling zone (104) with the help of supply fan (110).
The heat recovery system (100) further includes an air supply unit (112). The air supply unit (112) includes at least one heat exchanger (114) to recover heat from the hot air. The heat exchanger (114) includes air to water heat exchanger. It should be noted that the heat exchanger (114) may include any type and number of heat exchanger, without limiting the scope of the present invention. In these embodiments, the heat exchanger (114) includes a plate type heat exchanger. The heat exchanger (114) includes a heating coil (116). The exhaust air is passed through the heating coil (116) through the exhaust fan (108). The air supply unit also includes an enclosure (not shown) adapted at the supply fan having a prefilter section to filter dust particles in the fresh air. The enclosure also includes a burner section for maintaining a predefined temperature of the filter fresh air. The air supply unit (112) includes at least one water tank to store water. The air supply unit (112) also includes a water pump (120) to circulate water in the heat exchanger (114). More particularly, the water pump (120) circulates the water in the heating coil (116) of the heat exchanger (114) to extract the heat from the exhaust air. The water is in thermal communication with the hot air. More particularly, the water is circulated from the water tank to the heat exchanger (114) through the pump to pre-heated the water. The enclosure further includes a humidifier to sprinkle the hot water from the heat exchanger into the fresh air. The humidifier maintains relative humidity of the fresh air. An alternative arrangement of make-up water may also be present to maintain the required quantity of water in the water tank. The air supply unit (112) may alternatively include a combustion zone (not shown) which may use fuel or electricity to heat the fresh incoming air or water. The air supply unit (112) further includes air filter (122) to filter the incoming air into the oven cooling zone (104). The air filter (122) may include any type, size, number, and the like, without limiting the scope of the present invention.
The heat recovery system (100) further includes an automatic mode and a recirculation mode. In an embodiment of FIG. 1, the heat recovery system (100) includes the automatic mode. In the automatic mode, a supply of the fresh air is controlled with respect to a temperature gradient of the hot air and the fresh air. Further, the supply of the fresh air through the supply fan (110) is controlled by a variable frequency drive (VFD) of the supply fan (110) using one or more feedback temperature sensors (not shown) disposed at inlet and outlet of the fresh air. In the automatic mode, the heat recovery system (100) works automatically with the help of automation and controlled programmable logic controller (PLC).
In an embodiment of FIG. 2, the heat recovery system (100) includes the recirculation mode. In the recirculation mode, the humidifier uses the pre-heated water to maintain threshold relative humidity range of the fresh air. More particularly, the exhaust fan (108) is switch off and the hot air is allowed to pass through the heating coil (116) of the heat exchanger (114) to preheat the water before humidification process of the fresh air through the humidifier. This recovered heat is used to heat water in the water tank of the of the air supply unit (112). The air supply unit (112) provides a conditioned air to the supply fan (110) at threshold temperature range and at threshold relative humidity range. The air supply unit (112) provides the conditioned air between the threshold temperature range of 22⁰C to 25⁰C. The air supply unit (112) provides the conditioned air between the threshold relative humidity range of 65% to 75%.
The present invention provides an improved heat recovery system (100) for recovery of waste heat from the exhaust air through the heat exchanger (114) disposed in the air supply unit (112) of the heat recovery system (100). In recirculation mode, the exhaust fan (108) is turned off and the hot air is passed through the heat exchanger (114) which transfer heat to the air supply unit (112) to pre-heat the water. Moreover, the heat recovery system (100) reduces the fuel consumption and increases the overall efficiency of the process, thereby, reducing the overall cost of the process.
While aspects of the present disclosure have been particularly shown and described with reference to the embodiments above, it will be understood by those skilled in the art that various additional embodiments may be contemplated by the modification of the disclosed machines, systems, and methods without departing from the spirit and scope of what is disclosed. Such embodiments should be understood to fall within the scope of the present disclosure as determined based upon the claims and any equivalents thereof.
, Claims:
1. A heat recovery system (100) for a cooling zone for a paint shop for cooling a vehicle part (102), the heat recovery system (100) for the cooling zone comprising:
at least one exhaust fan (108) to exhaust a hot air from the cooling zone to an atmosphere;
at least one supply fan (110) to supply a fresh air into the cooling zone from the atmosphere; and
an air supply unit (112) having:
at least one heat exchanger (114) to recover heat from the hot air, the heat exchanger (114) includes air to water heat exchanger; and
an enclosure adapted at the supply fan (110) having:
a prefilter section to filter dust particles in the fresh air;
a burner section for maintaining a predefined temperature of the filter fresh air; and
a humidifier to sprinkle the hot water from the heat exchanger into the fresh air thereby providing a conditioned air to the supply fan (110) at threshold temperature range and at threshold relative humidity range.

2. The heat recovery system (100) as claimed in claim 1, wherein the air supply unit (112) provides the conditioned air between the threshold temperature range of 22⁰C to 25⁰C.

3. The heat recovery system (100) as claimed in claim 1, wherein the air supply unit (112) provides the conditioned air between the threshold relative humidity range of 65% to 75%.

4. The heat recovery system (100) as claimed in any of the preceding claims 1 to 3, wherein the air supply unit (112) has at least one water tank to store water.

5. The heat recovery system (100) as claimed in claim 4, wherein the water is circulated from the water tank to the heat exchanger (114) through the pump to pre-heated the water.

6. The heat recovery system (100) as claimed in any of the preceding claims 1 to 5, wherein the heat recovery system (100) includes an automatic mode and a recirculation mode.

7. The heat recovery system (100) as claimed in claim 6, wherein in the automatic mode, a supply of the fresh air is controlled with respect to a temperature gradient of the hot air and the fresh air.

8. The heat recovery system (100) as claimed in claim 6, wherein in the automatic mode, the supply of the fresh air through the supply fan (110) is controlled by a variable frequency drive (VFD) of the supply fan (110) using one or more feedback temperature sensors disposed at inlet and outlet of the fresh air.

9. The heat recovery system (100) as claimed in claim 6, wherein in the automatic mode, the heat recovery system (100) works automatically with the help of automation and controlled programmable logic controller (PLC).

10. The heat recovery system (100) as claimed in claim 6, wherein in the recirculation mode, a humidifier used the pre-heated water to maintain threshold relative humidity range of the fresh air.