Claims:CLAIMS:
We Claim:
1. A long-tail boat with heat exchanger, comprising:
an electric drive module;
a reservoir enclosing said drive module configured to store a coolant;
a long tail propulsion shaft connected to said drive module;
plurality of circulation conduits extending along the length of said long-tail propulsion shaft configured to said reservoir on one end;
a chamber configured on other end of the circulation conduits, to exchange heat from said coolant, and
at least one partition wall is positioned parallel to said long-tail propulsion shaft inside said chamber to provide a barrier for circulation of said coolant throughout said chamber and to divide said chamber into at least two compartments to achieve temperature drop in said coolant before outflow;
wherein said heat exchanger discharges heat and provide cooling for said long-tail boats.
2. The heat exchanger for cooling in long-tail boat drives as claimed in claim 1, wherein said plurality of circulation conduits comprises an inlet and outlet conduits form a closed-loop cooling system to circulate said coolant between said reservoir and said chamber.
3. The heat exchanger for cooling in long-tail boat drives as claimed in claim 1, wherein said plurality of circulation conduits extend along length of said long-tail propulsion shaft either longitudinally, or spirally, or helical, or any other form for heat transfer and fitted around said long-tail propulsion shaft.
4. The heat exchanger for cooling in long-tail boat drives as claimed in claim 1, wherein shape of said chamber comprises either cylindrical, or square, or spiral or any other similar shape to exchange heat from said coolant.
5. The heat exchanger for cooling in long-tail boat drives as claimed in claim 1, wherein said long-tail propulsion shaft and said chamber are arranged to achieve contact with water and to transfer heat from said coolant.
6. The heat exchanger for cooling in long-tail boat drives as claimed in claim 1, wherein said coolant is a fluid coolant which includes either a gas or a liquid or a nanofluid or combinations thereof.
7. The heat exchanger for cooling in long-tail boat drives as claimed in claim 1, wherein said partition wall is configured with at least one hole on rear end for transfer of said coolant to plurality of compartments.
8. The heat exchanger for cooling in long-tail boat drives as claimed in claim 1, wherein material of said chamber comprises copper or aluminum or any similar materials with optimum thermal properties and corrosion resistance. , Description:DESCRIPTION:
Field of the invention:
[0001] The present disclosure generally relates to the technical field of cooling systems for marine drives, and in specific relates to an electric long-tail boat with a heat exchanger designed to drive fishing or touring boats and to assist continuous removal of heat from a drive unit to function continuously for long period of time.
Background of the invention:
[0002] Water transportation is an important means of transportation in many countries since ancient times. Many regions of the countries are seaside or have thousands of rivers and canals around the cities. People usually transport goods and passengers by rivers, canals and coasts. In the past, small to large boats have been developed with low cost, and are easy to build with local material and easy maintenance aspects. Such boats have been slowly improving over the past centuries.

[0003] Over the last few years, the latest developments use modern materials such as aluminum, plastic, and fiber-reinforced plastic. Most of them, traditional or new designs, are equipped with an engine. Some of them use small general-purpose engines, the others use automotive diesel or gasoline engines. Nowadays, there is a spike in the development of electric boats (E-boat).

[0004] A significant problem faced by the marine drives is heating issues during operation. Marine drives that are operated at higher temperatures are more likely to fail. Furthermore, at high temperatures, marine drives may not fail catastrophically, but they may decrease in performance. High-temperature operation can result in power fluctuations, which can permanently damage the marine motor's propulsion system and the battery unit.

[0005] Conventionally, in the case of electric boats, it is often necessary to cool not only the electric motor but also the battery which provides the electrical supply for the electric motor. U.S. Pat. No. 8,535,104 B1 has disclosed a cooling system for a boat battery, wherein the battery is cooled by means of cooling air, which in turn is cooled by seawater. Cooling of the battery by convection that is to say by means of air flowing past, necessitates relatively large cooling surfaces, which are generally not available in the long-tail boat.

[0006] Further, a cooling water system is used to remove or conduct heat out of hot surfaces or materials from the engine, either directly or indirectly. Water is drawn in by means of a pump and supplied to the motor via a coolant line. The coolant line is in thermal contact with the motor, such that the motor and the coolant exchange heat and the motor is cooled. However, using seawater directly to cool engine component causes highly corrosive, and it contains significant amount of impurities which deteriorate engine working performance, and it contains calcium carbonate which causes difficulties to heat transfer process.

[0007] In existing technology, an electric stern board drive for marine electric propulsion comprises a closed-loop cooling system. A closed-loop liquid cooling system uses an underwater heat exchanger to dissipate excess heat through the surrounding water. In a closed-loop cooling system, the coolant circulated continuously in the system as needed to cool the motor. However, the system does not exactly indicate the cooling system for long-tail boats.

[0008] As noted previously, heat is removed from electric stern board drives with closed-loop heat exchanger easily accomplished in outboards, appears to be impossible in long-tail shafts. The reason for this is, outboards are mounted outside the ship's stern and have a heat exchanger on the base that is completely submerged. The long-tail engine, unlike outboards, is mounted above the boat and does not have a provision for a cooling chamber system for the electric drives. Therefore, it is desired to have a heat exchanger which is a different shape which may more easily fit into the long-tail boats.

[0009] Therefore, there is a need for an electric drive system consisting of cost-effective equipment’s with sustainable and budget friendly operation and maintenance. The system designed needs to be economically viable long-term drive associated with future technologies. Further, the system should be one of its kind with shaft integrated liquid cooling system that will aid in the transition of conventional diesel-powered long tail boats to electrically powered drives. The system requires a means which aids for continuous removal of heat, allowing the drive to function continuously for longer period of time. Further there is a need for a system which can avoid usage of outside water there by avoiding corrosion etc. to the parts of the cooling system and other components situated in the boat.
Objectives of the invention:
[0010] The primary objective of the invention is to provide a heat exchanger for an electric long-tail boat, which improves cooling of a drive unit or of other components present in the boat.

[0011] Another objective of the invention is to provide a heat exchanger for an electric long-tail boat that assist in the continual removal of heat and ensures that the temperature of the main engine/drive unit and control module within acceptable limits for optimal performance during operations.

[0012] The other objective of the invention is to provide a shaft mounted heat exchanger for effective heat transfer using a coolant for efficient cooling of the drive unit in electric long-tail boats.

[0013] Yet another objective of the invention is to provide a coolant in the heat exchanger for uniform cooling of the drive unit and the controller. The coolant returned from the heat exchanger chamber is further cooled by air surrounding the conduits.

[0014] Further objective of the invention is to provide a liquid cooling for electric long-tail boat drive to keep less noise of the drive unit as compared with air-cooled engines, as it has water for damping noise.

[0015] Another objective of the invention is, the temperature of drive unit or coolant is controlled irrespective of seawater’s temperature, the stable temperature is maintained such as to reduce machinery wear down.

[0016] The other objective of the invention is to provide great reliability and temperature control of the system offered by the shaft mounted heat exchanger makes it an ideal choice for electric long-tail boats.
Summary of the invention:
[0017] The present disclosure proposes heat exchanger for electric long-tail boat drives. The following presents a simplified summary in order to provide a basic understanding of some aspects of the claimed subject matter. This summary is not an extensive overview. It is not intended to identify key/critical elements or to delineate the scope of the claimed subject matter. Its sole purpose is to present some concepts in a simplified form as a prelude to the more detailed description that is presented later.

[0018] In order to overcome the above deficiencies of the prior art, the present disclosure is to solve the technical problem to provide a cooling systems for marine drives, and in specific relates to an electric long-tail boat with a heat exchanger designed to drive fishing or touring boats and to assist continuous removal of heat from a drive module to function continuously for long period of time.

[0019] According to an aspect, the invention provides a heat exchanger for cooling in an electric long-tail boat drives. The electric long-tail boat comprises an electric drive module, a reservoir enclosing the drive module configured to store a coolant, a long-tail propulsion shaft connected to the drive module. A plurality of circulation conduits extending along the length of the long-tail propulsion shaft configured to the reservoir on one end of the circulation conduits. The circulation conduits comprises an inlet and outlet conduits to form a closed-loop cooling system to circulate the coolant between said reservoir and the chamber. The circulation conduits extend along length of the long-tail propulsion shaft either longitudinally, or spirally, or helical, or any other form to achieve required heat transfer and fitted around said long-tail propulsion shaft.

[0020] A chamber configured on other end of the circulation conduits, to exchange heat from the coolant. The shape of the chamber comprises either cylindrical, or square, or spiral or any other similar shape to exchange heat effectively from the coolant. Further, the chamber made of either copper or aluminum or any similar alloys or materials with optimum thermal properties and corrosion resistance. The long-tail propulsion shaft and the chamber are arranged to achieve contact with water and to transfer heat from the coolant.

[0021] According to another aspect of the invention, inside the chamber, at least one partition wall is positioned parallel to the long-tail propulsion shaft to divide the chamber into a plurality of compartments. The partition wall provides a barrier for circulation of the coolant throughout the chamber and to divide the chamber into at least two compartments to achieve temperature drop in the coolant before outflow. Furthermore, the partition wall is configured with at least one hole on the rear end for transfer of the coolant to a plurality of compartments to achieve effective heat transfer from the coolant.

[0022] Further, objects and advantages of the present invention will be apparent from a study of the following portion of the specification, the claims, and the attached drawings.
Detailed description of drawings:
[0023] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate an embodiment of the invention, and, together with the description, explain the principles of the invention.

[0024] FIG. 1 illustrates an exemplary isometric view showing a heat exchanger connected to a long-tail propulsion shaft of electric long-tail boat in accordance to an exemplary embodiment of the invention.

[0025] FIG. 2A illustrates an exemplary schematic view of a heat exchanger connected to a long-tail propulsion shaft of long-tail boat in accordance to an exemplary embodiment of the invention.

[0026] FIG. 2B illustrates an exemplary detailed view of a heat exchanger with a partition wall connected to a long-tail propulsion shaft of electric long-tail boat in accordance to an exemplary embodiment of the invention.

[0027] FIG. 2C illustrates an exemplary detailed side view of a heat exchanger with a partition wall connected to a long-tail propulsion shaft of electric long-tail boat in accordance to an exemplary embodiment of the invention.

[0028] FIG. 3 schematic view of a spiral heat exchanger on the rear end of a long-tail propulsion shaft of long-tail electric boat in accordance to an exemplary embodiment of the invention.
Detailed invention disclosure:
[0029] Various embodiments of the present invention will be described in reference to the accompanying drawings. Wherever possible, same or similar reference numerals are used in the drawings and the description to refer to the same or like parts or steps.

[0030] The present disclosure has been made with a view towards solving the problem with the prior art described above, and it is an object of the present invention to provide a heat exchanger designed to drive fishing or touring boats and to assist continuous removal of heat from a drive module to function continuously for a longer period of time.

[0031] According to an exemplary embodiment of the invention, FIG. 1 refers to an isometric view showing a heat exchanger connected to a long-tail propulsion shaft of electric long-tail boat 100. The long-tail boat is designed to run on the electric power. The battery packs provide the necessary input power to run the entire system, and the system's input is regulated via a throttle arrangement. The electric drive setup, which consists of an electric drive module 104 and a controller 108, is contained in a robust enclosure 102 capable of delivering the required power without interruption.

[0032] The robust enclosure 102 comprise an electric drive module 104, a reservoir 106, and a controller 108. The reservoir 106 enclosing the drive module 104 configured to store a coolant. Further, the robust enclosure 102 comprises a power transmission shaft to connect the drive module 104 with the long-tail propulsion shaft 114. A plurality of circulation conduits (112 and 110) extending along the length of the long-tail propulsion shaft 114 configured to the reservoir 106 on one end. The whole unit 100 is easily mounted on the rear end of the long-tail boat and provide the required thrust needed to drive.

[0033] The heat exchanger with a chamber 116 configured on other end of the circulation conduits (112 and 110) extend along the length of the long-tail propulsion shaft 114 to exchange heat from the coolant in the electric long-tail boat. The shape of chamber is cylindrical or any other shape to achieve similar rate of exchange of heat from the coolant. One end of the long-tail propulsion shaft 114 equipped with a propeller and other end connected to the power transmission shaft. The power transmission shaft is placed in the robust enclosure 102 where the drive module 104 is installed. The power transmission shaft configured to transfer power from the drive module 104 to the long-tail propulsion shaft 114 utilizing a belt drive.

[0034] Further, the heat exchanger comprises plurality of circulation conduits (112 and 110) extending along the length of the long-tail propulsion shaft 114 configured to reservoir 106 on one end and with a cylindrical chamber 116 on the other end. The plurality of circulation conduits comprises an inlet 112 and outlet 110 conduits to form a closed-loop cooling system to circulate the coolant between the reservoir 106 and cylindrical chamber 116. The inflow conduit 112 configured to receive the hot coolant circulated in the drive module 104 with the controller 108 to the cylindrical chamber 116 of the heat exchanger. The outflow conduit 110 configured to send the coolant from the cylindrical chamber 116 of the heat exchanger to the reservoir 106. The inflow and outflow conduits (112 and 110) with respect to the cylindrical chamber 116 provides a channel for flow of the coolant along the length of a long-tail propulsion shaft 114 of the long-tail boat. The cylindrical chamber 116 is placed in such a way that it gets in contact with water to increase the heat transfer rate from coolant to water in the water body.

[0035] A submersible pump is mounted on reservoir 106 to ensure the circulation of coolant throughout the cylindrical chamber 116. The coolant in the reservoir 106 absorbs heat from the drive module 104 and the controller 108. The temperature of the coolant rises when in contact with the drive module 104 and the controller 108. This hot coolant then flows through the inflow conduit 112 to the heat exchanger with cylindrical chamber 116. The heat exchanger with cylindrical chamber 116 is installed on the long-tail propulsion shaft's 114 rear end, which is always submersed inside the water. The hot coolant in the cylindrical chamber 116 exchanges heat with its surrounding water, releases significant amounts of heat from the coolant, and thus lower its temperature.

[0036] According to another exemplary embodiment of the invention, FIG. 2A, 2B and 2C refers to a detailed view of a heat exchanger 200. The heat exchanger comprises a cylindrical chamber 216 configured on other end of the circulation conduits (210 and 212) to exchange heat from the coolant. The cylindrical chamber 216 on the rear end of the long-tail propulsion shaft 214 of the long-tail boat.

[0037] Further, the heat exchanger 200, comprises two circulation holes (218 and 220) on one end of the cylindrical chamber 216. The other end or the rear end of the cylindrical chamber 216 is completely sealed on the long-tail propulsion shaft 214. The circulation holes (218 and 220) configured for inflow and outflow of the coolant through an inflow and outflow conduits (212 and 210).

[0038] Furthermore, the heat exchanger 200, comprises a pair of partition walls 222 to divide the cylindrical chamber 216 into two chambers. The partition walls 222 divides the cylindrical chamber 216 in such a way that the inflow circulation hole 218 is in one compartment and the outflow circulation hole 220 is in the other compartment. The partition walls further configured with a passage hole 224 at the opposite end of the inflow and outflow circulation holes (218 and 220) to ensure the coolant flows through the entire cylindrical chamber 216 before entering into the outflow conduit 210.

[0039] The coolant from the reservoir module absorbs heat from the drive module and the controller. The temperature of the coolant rises when in contact with the drive module and the controller. This hot coolant then flows through the inflow conduit 212 to the heat exchanger 200 with cylindrical chamber 216. The heat exchanger200 with cylindrical chamber 216 is installed on the long-tail propulsion shaft's 214 at rear or distal end, which is designed to submerse inside the water.

[0040] The coolant enters the cylindrical chamber 216 from the inflow conduit 212 through an inflow circulation hole 218. Once the coolant enters the cylindrical chamber 216, the hot coolant flow throughout the cylindrical chamber 216. Further, a passage hole 224 is provided on the partition walls 222 at the opposite end of the inflow and outflow circulation holes (218 and 220) to maintain the flow. Due to the partition walls 222 the coolant flows through the entire cylinder 216 before moving out of the cylindrical chamber 216. This ensures a large drop in the coolant temperature before entering into the outflow conduit 210.

[0041] According to another exemplary embodiment of the invention, FIG. 3 refers to a schematic view of a spiral heat exchanger on the rear end of a long-tail propulsion shaft 300. The hot coolant from the inflow conduit travel across the entire length of the spiral heat exchanger 316. The spiral heat exchanger 316 extend along the length of the long-tail propulsion shaft 314 at the distal end. The spiral heat exchanger 316 fitted spirally to the long-tail propulsion shaft 314, which is always submersed inside the water. As spiral heat exchanger 316 increases the surface area significantly, this in turn increases the heat transfer rate occurred due to forced convection from the surface. The hot coolant upon entering the spiral heat exchanger 304, exchanges heat with its surrounding water, releases significant amounts of heat from the coolant and thus lower its temperature before entering the outflow conduit.

[0042] Numerous advantages of the present disclosure may be apparent from the discussion above. In accordance with the present disclosure, an electric long-tail boat with a heat exchanger is described in accordance with the present disclosure, which allows for improved cooling of a drive module or other components in the boat. The heat exchanger aids in the continual removal of heat to keep the temperature of the drive module and the controller within acceptable limits for maximum performance throughout the operation of the boat.

[0043] The proposed heat exchanger provides a coolant for uniform cooling of the drive module and the controller. The coolant returned from the heat exchanger after cooling the drive module is cooled by surrounding water. The liquid coolant heat exchanger for long-tail boat drive to keep less noise of the drive module as compared with air-cooled engines, as it has water for damping noise. Moreover, the present disclosure provides a great reliability and temperature control of the system offered by the shaft mounted heat exchanger makes it an ideal choice for long-tail boats.

[0044] In an alternative embodiment, the material of a heat exchanger with cylindrical chamber may comprise copper or aluminum or alloys or any similar materials with optimum thermal properties and corrosion resistance. The coolant may comprise a fluid coolant comprising either a gas or a liquid or a nanofluid or combinations thereof to achieve the required temperature change at the drive module. The shape of the heat exchanger may be rectangular or square or any similar shapes which can easily mount on the long-tail propulsion shaft. To produce a high temperature drop from the coolant, the cylindrical chamber may prolong the length of the long-tail propulsion shaft. Any sort of heat exchanger, such as a shell and tube heat exchanger, a double pipe heat exchanger, or a plate heat exchanger, can be used. Different flow-based heat exchangers, such as concurrent flow, counter flow, cross flow, or hybrid flow heat exchangers, may be used as heat exchanger.

[0045] It will readily be apparent that numerous modifications and alterations can be made to the processes described in the foregoing examples without departing from the principles underlying the invention, and all such modifications and alterations are intended to be embraced by this application.