GB2595200A

GB2595200A - Apparatus for cooling of habitat of automobiles

Info

Publication number: GB2595200A
Application number: GB2000924.7A
Authority: GB
Inventors: Cassells Sharp Allan; Gabriel Georghiou Elena
Original assignee: Marr Ramsay
Current assignee: Marr Ramsay
Priority date: 2020-01-21
Filing date: 2020-01-21
Publication date: 2021-11-24
Anticipated expiration: 2040-01-21
Also published as: GB2595200B; GB202000924D0; GB2595200A8; GB2595200B8

Abstract

A thermo-electric generator (TEG) (3, Fig 1) that is attached to the underside of a vehicle roof panel (1, Fig 1) which powers an on-board cooling unit 6. The cooled air (12, Fig 1) is conveyed through ducting 8 to a heatsink (4, Fig 1) that cools the underside of the TEG and also through duct 7 to cool the vehicle interior environment. The vehicle roof panel may have a heat-absorbing coating such as a matt-black surface. The air may be exhausted out of the vehicle via ducts 9 and exit vent 11. The TEG may be used to power the heating ventilation air conditioning (HVAC) unit when the vehicle is switched off or the primary power unit is not in operation. The apparatus may have a ECU operated check valve 10 to ensure that warm air (15, Fig 1) flows uni-directionally out of the exit vent 11.

Description

SPECIFICATION

APPARATUS FOR COOLING OF HABITAT OF AUTOMOBILES

1. Field of the Invention

The present invention relates to the field of air-conditioning of the habitats of automobiles with saloon cars at the lower end of the range and coaches at the upper end, though this is not to be construed as a deliberate limitation to wider applications but more as indicative to the scope of work undertaken to-date by the applicants. The Thermo-Electric Cooling process for automobiles is based on the use of thermo-electric generators (TEGs) to provide energy for a cooling unit of which the output of cooler air shall be provided to the interior of the automobile to which it is fitted, either integrally at manufacture or as an add-on to automobiles which are already in use. TEGs require a heat differential across their section to create a potential difference (Voltage) which is harnessed for power, sufficient power for a cooling unit of up to 40W for a medium-size saloon car with appropriate scaling for larger vehicles such as coaches. Two TEGs, each of circa 20W output at service temperatures, arranged in series in the roof with a cooling duet on the underside shall suffice for power generation to the cooling unit, said unit to operate whilst the saloon car is not in use. The invention has application to vehicles of combustion engines or electric-powered or any combination thereof.

2. Description of the Prior Art.

The habitats of automobiles are maintained in the comfortable temperature range by cooling units of which the fan is powered by the primary battery, said battery having its charge maintained by the alternator driven by the car engine in the case of combustion engines, and the compressor is driven by the engine via a belt-drive arrangement. For the recently-developed electric motors, the cooling units are driven directly from the main battery. When the automobile is not in use, the air-conditioning is disabled to prevent the drainage of power from the primary battery thus allowing the habitat to reach uncomfortable and often life-threatening temperatures within the habitat when weather conditions permit. Additionally, when driver and/or passengers return to said automobile, the engine and associated air-conditioning would necessarily run for a period until the habitat is comfortable, thus consuming fuel.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features of this invention are set against the background of its applications in the detailed description which follows and in conjunction with accompanying drawings wherein; Figure 1 depicts a saloon car, with roof-integrated Thermo-electric generators and ducting.

Figure 2 depicts a section through the roof of the saloon car with corresponding sections through a TEG showing air flow, the heat flow being explained in corresponding text.

It should be noted that these drawings are not to scale and should not be construed as being so but where scale is provided, it is done so as indicative only.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The use of thermoelectric generators (TEG's) in automotive applications remains of significant interest. To-date, research has focused on the use of exhaust systems as the primary source of heat to power these devices. This invention presents the use of direct sunlight to offer an alternative using the heat generated at the surfaces of the car as a thermal source. Two alternative system designs were tested and evaluated using a combination of simulation and experimental testing, identifying novel opportunities for this approach. An initial design consisted of a TEG module fitted in free space below a glass panel. Results indicate that per module power generation at scales greater than milliwatts is challenging using this approach. The power provided by solar irradiation scales with area, thus the small surface area of a typical consumer, off-the-shelf (COTS) TEG module significantly limits absolute power input and module temperature differences. Following analysis of results, an alternative design was proposed and evaluated. In this system, a COTS TEG module was mounted directly behind the surface of an aluminium panel 200mm x 250mm in size and intended to replicate a car-body panel. This approach sought to increase input system power by using the increased area of the panel as a solar collector. Results revealed significant increases in TEG performance over that from a TEG module mounted behind a glass plate. The effects of cooling on system performance were also investigated. It has been found that cooling offered an opportunity to control mean system operating temperature but had little impact on temperature differences across the TEG itself. Taken together, these findings confirm theoretical predictions that TEG power output and temperature difference are a function of module geometry, material thermal conductivity and heat input. This suggests practical opportunities to increase system power further by increasing the panel area acting as a solar collector in the first instance, and by increasing TEG element length using custom manufactured modules as a further option. Thus, by placement of a heat sink on the underside of a TEG, the power output could be optimised to facilitate development of supplementary cooling when the primary power source for air-conditioning is not in operation. Such a supplementary cooling system, best termed supplementary heating-ventilation-air conditioning (HVAC) unit, shall be integrated with the on-board Electronic Control Unit (ECU) of the automobile.

The roof 1 of the vehicle of the embodiment is of a material which is thermally conductive to an extent which renders this invention workable, typical materials would be aluminium-alloys and graphene. Solar heat, which would cause unacceptable temperatures in the habitat, also impinges on the roof and, by suitable design with conductive and insulating materials 2, this heat is directed preferentially to the TEG 3 through which it drains to the heat sink 4 on the underside of said TEG 3, and on the under-surface of heat sink 4 is provided a current of air 12 within retaining ducting 5 to remove the surplus heat. The flow of heat through the TEG creates a power output, made available to the supplementary HVAC unit 6 which provides cool air 12 both to the habitat and also to the under-side of the TEG for removal of heat which, by flowing through the roof into the habitat, would otherwise negate the cooling effect of the primary air circulation. This cooling air 12, to the cooling fins of the heat sink 4 located on the underside of the TEG 3, is necessarily exhausted by ducting 9 to the environment and the quantity thus exhausted is recompensed by additional air introduced through suitable matched-venting in the HVAC unit 6.

The manner by which the HVAC unit 6 and its attendant ducting 7,8 to both habitat and heat sink 4 of TEG 3 respectively are incorporated into the automobile is greatly dependent on the design process of the manufacturer and it is emphasised that this embodiment serves only as a means of explaining the general principles of equipment and operation.

An ECU-operated check valve 10 shall ensure that warm air 15 flows uni-directionally out of the habitat through vent Il and that no particulates and debris pass into the controlled enclosure. It is anticipated that variables in the functional sections would include pressure drop across the cooling fins which would be dealt with by way of example, by dimension 'Z'. Of greater interest would be cooling of air before contact with cooling fins, as utilising the Joule-Thomson effect where cooling air in ducting 8 passes through a reduction in the cross-section of the ducting followed by an abrupt expansion, duly verified by testing.

Claims

CLAIMS* We claim: 1. Apparatus for cooling the habitat of automobiles by thermo-electric power, said power provided by Thermo-Electric Generators (TEG) of optimal quantity, with heat from the environment being channelled to flow, by appropriate design and materials' selection, to the hot-end of each TEG duly attached to the underside of the roof panel, and the flow of heat is induced through the TEG by a forced cooling of the underside of the TEG by cool air conveyed by ducting to a heat sink thereby generating power which is available for and directed to an on-board cooling unit which provides cooling air to the habitat of the automobile and the underside of the TEG as aforementioned thereby removing heat from the TEGs 2. The roof panel of claim 1 which is coated in a heat-absorbing coating, typically though not specifically matt-black 3. The underside cooling of claim 1 which is characterised by a stream of cool air from the cooling unit, said air being directed by appropriate ducting to the underside of the TEG and the cooling fins of the heat sink, said air then exhausted out of the vehicle 4. The apparatus of claim 1 as utilised when the primary power unit of the automobile is not in operation.5. The exhaust of claim 3 of warm air from the underside of the heat sink of TEGs conveyed to the exterior by ducting and associated vents configured in a manner as to ensure uni-directional flow, said ducting to have sufficient insulation to prevent a reflux of heat into the interior 6. The ducting of claim 1 which shall include a reduction of cross-section area with abrupt expansion immediately before the heat sink of claim 1