DESC:Preamble to the Description
The following specification particularly describes the invention and the manner in which it is to be performed:
DESCRIPTION OF THE INVENTION:
Technical field of the invention
[0001] The present invention relates to an air-cooling system for a saddle type vehicle, and more particularly, an air-cooling system configured for using the ram air for dissipating heat generated from battery pack.
Background of the invention
[0002] Electric vehicle requires higher power density to be packed into a battery pack. It is always expected that the battery can be arranged as much as possible, however, which leads to the serious thermal management issue due to the heat generation inside the battery packs.
[0003] The performance of Lithium-Ion battery cells is greatly impacted by their temperature, they suffer from the Goldilocks effect, they do not perform well when too cold or too hot, which can lead to permanent and extreme damage of the cells or accelerated degradation. So in addition to cooling, heating of the cells may also be required at lower ambient temperatures to prevent damage during fast charging when the cells are too cold; this is because the internal resistance of the cells rises when they are cold. Most lithium battery cells cannot be fast-charged when they are less than 5oC and cannot be charged at all when they are below 0oC. Lithium cells also begin to degrade quickly when their temperature is above 45oC.
[0004] In the past, the largest battery packs did not necessarily need any special cooling as the physical size of the packs was sufficient and the relative flow of current was not large compared to the overall capacity of the pack. As ever faster battery charging rates are demanded with recharge power of over 200kW to deliver times of 30 minutes or less, higher performance electric vehicles with a requirement for consistent performance and adequate durability in global markets has meant that special thermal management methods for the battery pack are now required.
[0005] Heat is a major battery killer and Lithium secondary cells need careful temperature control. Operating at high temperatures brings on a set of different problems which may result in the destruction of the cell: unless heat is removed faster than it is generated, a thermal runaway may occur
[0006] A thermal management system is required for a battery to attain effective operation and long life in all environmental conditions. Although several types of thermal management system are available, there remains a need to address various issues like high power consumption, narrow optimum temperature range and operation in varying climates.
[0007] There are four main sources of heat production in working batteries, namely, reaction heat (RH), side reaction heat (SRH), joule heat (JH) and polarization heat (PH). The total calculation of the heat generation is shown in Equation - Ptotal = Pre + Psr + Pjo + Ppo
[0008] Where Ptotal represents the power of the total heat, Pre represents the power of RH, Pse represents the power of SRH, Pjo represents the power of JH, and Ppo represents the power of PH.
[0009] RH refers to the heat generated by the chemical reaction in the electrodes in charging and discharging. Generally, the charging process of LIB absorbs energy to reduce ambient temperature and in reverse, its discharging process releases heat. These results in a side reaction, that is, heat is generated by a series of chemical reactions other than the main chemical reaction, such as the partial decomposition of electrolyte at high temperature and self-discharge caused by the change in electrode material structure.
[0010] These side reactions are intensified in the period before the battery fails. However, during the life of the battery, the side reactions are so weak that the heat of the side reaction is usually ignored. JH is the work done by the current on the internal resistance (IR). This part of the heat can be calculated by Joule’s law as shown in Equation-Pjo = I 2R?, where R? is IR, and I refers to the current on R?.
[0011] PH refers to the heat generated when the positive and negative electrode potential deviates from the equilibrium potential. When polarization occurs, the voltage difference between the battery’s open circuit voltage and the terminal voltage generate PH. Generally, it is assumed that there is a polarization IR Rp, and the heating power is calculated by Joule’s law, as shown in Equation- Ppo = I 2Rp.
[0012] An effective thermal management system is required in order to optimize the performance of the battery pack by maintaining battery temperature within operating range and reducing temperature non-uniformity in battery packs. A thermal management system would ensure that the cell temperatures are kept in the operating range so as to provide sufficient power capability while also ensuring temperature uniformity within cells so as to prevent degradation and faster aging of cells.

[0013] There are four common battery thermal management methods used today
a) Convection air either passively or forced
b) Cooling by flooding the battery with a dielectric oil which is then pumped out to a heat exchanger system.
c) Cooling by the circulation of water-based coolant through cooling passages within the battery structure.
d) Phase change material cooling
[0014] Although liquid cooling and PCM cooling ensure better cooling effect, air cooling is highly favored for its overall performances (light weight, low cost, long life, etc.)
[0015] In the Air-cooling battery thermal management solution, the air is the cooling medium and removes the heat generated by the battery cell. This cooling method classified into Passive cooling (Natural convection) and Active cooling (Forced Convection). The former passive (only ambient environment used) typically used for low-density batteries, and the latter active (special components provide for heating or cooling at cold or hot temperatures) use fans/blowers to enhance convection.
[0016] Reference can be made to US5613569 which discloses about an electric motor vehicle which permits reduction of the width of the lower side of the battery, and which is capable of cooling the battery effectively and removing magnetic dusts from cooling air for the electric motor without resorting to a filter.
An electric motor vehicle includes a battery unit mounted on the vehicle body to supply current to the electric motor. The battery unit is formed in an elongated shape in outer configuration and located under the vehicle body with the lengthy side of the battery unit disposed in the longitudinal direction of the vehicle body.
[0017] Reference can be made to US8739908 which discloses about a motor driven vehicle including a swing arm swingably mounted to a vehicle body of the motor driven vehicle and housing an electric motor driving a drive wheel of the motor driven vehicle. A pipe-like duct can have one end side connected to a hole communicating with an inside space of the swing arm, and the other end side extending toward the vehicle body side. A harness, used to drive the electric motor, is inserted through the duct.
[0018] Reference can be made to JP20010191388 In order to achieve the above object, the present invention provides a scooter type vehicle having a step floor at the front lower part of a seat, and a battery for an electric vehicle in which a battery unit in which a plurality of batteries are integrated is mounted under the step floor. The device has a first feature in that a cooling fan for cooling the battery unit is provided at two locations in the front-rear direction of the vehicle body. Further, the present invention has a second feature in that one of the cooling fans provided on the rear side of the vehicle body is disposed on the upper part of the battery unit, and among the cooling fans, on the front side of the vehicle body. What is provided is coupled to the front surface of the battery unit, and among the cooling fans, the one provided on the rear side of the vehicle body is coupled to the rear surface of the battery unit via a duct.
[0019] Reference can be made to EP2726311A2 which discloses about a duct by which ambient air can be introduced by means of the wind in the duct. This is achieved in particular by aligning the air shaft and / or at least the air inflow region or an inlet opening of the air shaft in the longitudinal direction of the vehicle, so that during operation of the vehicle, at least in the case of longitudinal movement of the vehicle, the air surrounding the vehicle in the air channel due the vehicle movement is flowing.
Brief Description of drawings
[0020] Fig.1 illustrates a left side view of the vehicle, in accordance with an embodiment of the present subject matter.
[0021] Fig.2 depicts an exploded view of the cooling pathway
[0022] Fig. 3 depicts frontal view of the cooling pathway
[0023] Fig. 4 depicts the graph plotted for analysis of battery temperature without cooling system.
[0024] Fig. 5 depicts the graph plotted for analysis of battery temperature with cooling system.

PROBLEM TO BE SOLVED
[0025] In the above mentioned prior arts, battery device is cooled using a cooling fan, a large cooling fan or multiple cooling fan is required. It may be difficult to secure the space. In addition, it is necessary to devise a technique for uniformly cooling the entire large-capacity battery and simultaneously keeping the cooling structure less complicated with use of ram air.

OBJECT OF INVENTION
[0026] Main object of the invention is to provide a method for providing uniform cooling effect for the entire battery without adding any additional cooling devices.
[0027] Another object of the present invention is to use environmental air for the purpose of cooling of the battery pack.
[0028] Another object of the present invention is to utilize the existing layout for routing of the air to the battery pack.
[0029] Yet another object of the present invention is to replace costlier system which involves forced cooling or other methods of cooling as they require regular maintenance and is costlier than our simple conventional cooling method.

GENERAL STATEMENT OF INVENTION
[0030] The lowest cost method for EV battery cooling is with air. A passive air-cooling system uses outside air and the movement of the vehicle to cool the battery. Air cooling eliminates the need for cooling loops and any concerns about liquids leaking into the electronics. The added weight from using liquids, pumps and tubing is also avoided.
[0031] Further, to devise a technique for uniformly cooling the entire large-capacity batteryand simultaneously keeping the cooling structure less complicated with use of ram air.

SUMMARY OF THE INVENTION

[0032] Dual air intake in vehicle frontal area is provided for natural airflow during vehicle drive condition, air is channelized using ram air intake affect to feed into battery area for convection cooling.

DETAILED DESCRIPTION OF THE INVENTION

[0033] Preferred embodiments of the present invention will hereinafter be described in detail with reference to the drawings. In various figures, a vehicle body includes a head pipe or front frame connected to a rear frame. As is well known in the art, a front wheel is supported on a front fork of the head pipe steerably in association with a steering handle. A front cowl and a rear cowl are provided to the vehicle body frame. A seat is mounted on top of the rear cowl. In the drawings, for the sake of simplicity of illustration, the cowls are shown as one unitary body without indicating their boundaries.
[0034] Fig. 1 is a lateral view of an electric vehicle 100 according to an embodiment of the present invention. The electric vehicle 100 can be, for example, a scooter-type straddle-ride two-wheeled vehicle having a flat-floor. A rear wheel WR is driven by hub mounted electric motor. proximal end of the a hose like structure 105 can be seen exposed to the direction of atmospheric air 102, the said proximal end of hose like structure 105 is aligned with the opening 103 provided at the lower front part of the cowl. The said hose like structure 105 is a part of cooling pathway which helps to bring down the temperature of the battery pack module 106 by means air convection.
[0035] Fig.2 is an exploded lateral view showing the cooling pathway for the battery pack module 106, 201 depicts the flow of air from the environment into the vehicle which is transported through the hose like structure having an elongated “S” like bend 202 which opens to the battery pack module 106 for providing environmental air to the said battery pack module 106 for dissipating the heat generated from the battery pack.
[0036] Fig.3 is a frontal view of the vehicle which depicts the routing of the cooling pathway for the battery pack module 106, 301 and 301’ are the integrated portion of the front cowl provided above the front fender of the electric vehicle 100, 301 and 301’ collects the environmental air and passes it to the hose like structure 105 (not shown in figure) which are routed as depicted by 302 and 302’ which are overlapping with the wheel well from the inside of the wheel well and is extended towards the floor board of the vehicle.
[0037] The battery pack used was a 60V 50Ah NMC Battery where we have smart BMS installed, with the help of this BMS we are able to configure and monitor the battery parameters. Parameters such as Pack voltage, Temperatures, Soc etc can be monitored over Bluetooth and CAN 2.0
[0038] For our testing’s, we have configured the BMS with 2 Temperature sensors which are NTC type. The sensors were placed at the point of max heat generation near to pack centre and near output connector.
Table 1- BATTERY TEMPERATURE WITHOUT COOLING SYSTEM
BATTERY TEMPERATURE WITHOUT COOLING SYSTEM
TIME T 1 T2 Pack Volt. SoC
09:32:00 28 24 65.8 99
09:35:00 28 26 63.6 98
09:45:00 31 30 62.6 87
09:55:00 35 35 60.8 75
10:05:00 37 40 59.3 62
10:15:00 40 42 57.4 50
10:25:00 42 48 55.5 37
10:35:00 46 51 53.5 24
10:45:00 51 57 51.9 13
10:46:00 51 57 46 0

Table 2- BATTERY TEMPERATURE WITH COOLING SYSTEM
BATTERY TEMPERATURE WITH COOLING SYSTEM
TIME T 1 T2 Pack Volt. SoC
10:18:00 28 24 65.8 99
10:20:00 28 26 63.7 98
10:30:00 29 29 62.7 88
10:40:00 33 34 61 77
10:50:00 34 36 59.5 63
11:00:00 36 41 57.6 52
11:10:00 38 43 56 38
11:20:00 42 48 54 25
11:30:00 43 49 52 14
11:38:00 44 50 46 0

[0039] Fig. 4 and Fig 5 depicts full discharge cycle, temperature at these points along with battery voltage and SOC were recorded for every 10minute of ride and graph was plotted with and without cooling system. Graph plotted between SOC,T1,T2 and Pack voltage with respect to discharge time clearly shows improved thermal management by our cooling system.
[0040] Without cooling system, for full discharge cycle, temperature of battery raised up to 57degrees whereas with our cooling system temperature raised up to 50 degrees improving thermal management by 7degrees.

List of References-
Electric vehicle-100

Cooling airway path-102

Opening on the front cowl-103

Hose like structure-105

Battery pack module-106

“S” like bend-202

Integrated portion of the front cowl -301 & 301’

Routing of the hose – 302 &302’

,CLAIMS:CLAIMS
What is claimed is:

1. An electrically powered scooter having a step floor, a seat, a body cover mounted under said seat, and a storage compartment located below said seat, said scooter comprising:a battery pack module under said step floor, said battery pack module is open to the surrounding air for allowing the flow of atmospheric air therethrough;a plurality of hoses are connected between one or more openings formed on the front cowl for intake of atmospheric air and said battery pack module, said plurality of hoses forming a passage for said atmospheric air to pass therethrough to form a cooling system.

2. The electrically powered scooter according to claim 1, wherein said plurality of hoses are placed outward of the right and left pair of front forks.

3. The electrically powered scooter according to claim 1, wherein said plurality of hoses are in “S” shaped, wherein it’s proximal end is located towards the opening at the front cowl .

4. The electrically powered scooter according to claim 1, wherein said plurality of hoses are in “S” shaped, wherein it’s distal end is located towards battery pack module located under said step floor.

5. The electrically powered scooter according to claim 2, wherein the said proximal end is located above the front wheel well and which is the longer part of the “S” shaped plurality of hoses.

6. The electrically powered scooter according to claim 3, wherein the said distal end is located beneath the step floor and which is the shorter part of the “S” shaped plurality of hoses.

7. The electrically powered scooter according to claim 1, wherein said front cowl for intake of atmospheric air is positioned in such a manner that it is partially overlapping the upper-bracket of the front forks when viewed from the front.

8. The electrically powered scooter according to claim 1, wherein said front cowl for intake of atmospheric air comprises of hollow chambers on each right and left side of the front cowl above the front fender.

9. The electrically powered scooter according to claim 1, wherein said front cowl for intake of atmospheric air and the said plurality of hoses does not bear a physical connection to avoid any damage due to rattling or the vibrations caused during the travel.

10. The electrically powered scooter according to claim 1, wherein said cooling system helps to improve thermal management of the said battery pack module by 7degrees.

Dated-22 Feb 2023 Signature of the Agent
Rajat Chaudhary IN/PA-3136