GB2361307A

GB2361307A - Air conditioning systems

Info

Publication number: GB2361307A
Application number: GB0009174A
Authority: GB
Inventors: Dominic Adam Simler
Original assignee: Individual
Current assignee: Individual
Priority date: 2000-04-14
Filing date: 2000-04-14
Publication date: 2001-10-17
Also published as: GB0009174D0

Abstract

An air conditioning system for an enclosed space which comprises an oxygen dispenser (1) for dispensing substantially pure oxygen or highly oxygen-enriched air into the air being conditioned by the air conditioning system, which oxygen dispenser comprises an oxygen accumulated (12) having an activation means or a flow control valve (18) to control directly or indirectly the generation or flow of the oxygen-enriched air from the dispenser, the activation means or flow control valve being under the control of control signals from a controller (8) responsive to oxygen level sensors (9) operatively linked to the controller to sense the level of oxygen in the air of the enclosed space. The dispenser (1) includes a compressor (11), sieve beds (18), filter (14) for particulates, pressure regulator (19), filter (16) for bacteria, and a flow meter (17). An air-conditioning unit (2) for cooling, dehumidifying or filtering air and including the oxygen dispenser (1), has an additional pump (5).

Description

2361307 IMPROVEMENTS TO AIR CONDITIONING SYSTEMS

Field of the Invention

The present invention relates to air conditioning systems and includes within 5 its scope not only air conditioning for buildings but also air conditioning/climate control for motor vehicles and other enclosed spaces.

Backaround to the Invention

Air conditioning systems are nowadays in widespread usage around the world most especially in those countries where climatic conditions of heat and humidity can make working intolerable. Although historically the UK market has tended to ignore air conditioning for any but the largest and most prestigious buildings and cars, economy of scale and price competition have brought down the cost of the more basic air conditioning systems to the level where the majority of new cars sold nowadays are offered with air conditioning as standard or as a low cost option and where even the smallest of offices may now be equipped with air conditioning.

Generally these air conditioning systems are configured to control the temperature of air in the internal environment by taking in air from the exterior at intervals and, as necessary, cooling it and then recirculating it cyclically around the internal environment within the building or vehicle. Other aspects of the air that may be conditioned include the humidity and pollutant content, amongst others.

The induction of air from the external environment to intermittently replace the internal air is, of course, generally necessary to replenish the oxygen levels in the air in the internal environment since this will eventually be depleted by the occupants of the internal environment and induction of external air from other sources will generally be prevented by closure of any windows or doors in order to maintain the internal circulatory flow of air and operation of the conditioning system, Despite intermittent or continuous induction of air from the external environment, maintenance of satisfactory oxygen levels may prove difficult.

The benefits of inhaling substantially pure oxygen for limited duration's to compensate for hypoxia are becoming increasingly broadly appreciated. Most commonly, individuals suffer from hypoxia following high levels of exertion in a relatively poorly ventilated environment. However, in an air conditioned environment the ventilation may often be so poor or unreliable that even the relatively inactive may suffer.

It is a general objective of the present invention to provide an improved air conditioning system which is able to appropriately compensate for diminished oxygen levels in a safe, reliable and economical manner.

Summa[V of the Invention According to a first aspect of the present invention there is provided an air conditioning system for an enclosed space which comprises an oxygen dispenser for dispensing substantially pure oxygen or highly oxygen- enriched air into the air being conditioned by the air conditioning system, which oxygen dispenser comprises an oxygen concentrator having an activation means or a flow control valve to control directly or indirectly the generation or flow of the oxygen-enriched air from the dispenser, the activation means or flow control valve being under the control of control signals from a controller responsive to oxygen level sensors operatively linked to the controller to sense the level of oxygen in the air of the enclosed space.

The controller is preferably adapted to regulate the oxygen level of the air in the enclosed space within a range of about 21 % to about 40% oxygen content and more preferably to between about 21 % and under about 30%.

2 The dispenser incorporates an oxygen concentrator to provide a substantially inexhaustible supply of oxygen-enriched air. An oxygen concentrator in its broadest sense is any device that concentrates the oxygen already present in air.

Most oxygen concentrators use PSA (Pressure Swing Adsorption) technology to concentrate the oxygen. PSA consists of a process where a gas is fed at an elevated pressure to a vessel containing an adsorbent matrix. The adsorbent matrix selectively adsorbs one or more of the non oxygen gas components such as nitrogen and carbon dioxide. Thus, the produced gas is enriched in the oxygen and any other components that have had least absorption. The adsorbent bed is regenerated by: 1) reducing the pressure in the vessel and 2) flowing some high purity gas through the adsorbent particles. At least two adsorbent beds are used so that continuous flow of the enriched gas can be obtained. When one vessel is adsorbing gas, the adsorbent in the other vessel is being regenerated. Typical adsorbent materials which are used to comprise carbon molecular sieves, zeolite molecular sieves, activated carbon, silica gel and activated alumina.

As noted above, the term air conditioning system, relates to a system for improving the quality of air in an enclosed space. The oxygen dispenser is suitably installed in the air conditioning system in such a way as to receive air that is drawn into the air conditioning system from outside of the confined space and so that the oxygen dispenser can dispense oxygen or oxygen enriched air into the enclosed space but expel oxygen depleted air (particularly nitrogen andlor carbon dioxide gases) externally of the confined space. Alternatively but less preferably, the air that is fed to the oxygen concentrator of the oxygen dispenser may be the air of the internal space that is re-circulated through the air conditioning system, but again it is 3 e desirable that the oxygen depleted air from the oxygen concentrator is exhausted externally of the enclosed space in order to create a net gain in the oxygen level in the enclosed space.

Fundamentally, the oxygen level in the confined space must not be allowed to exceed a safe operating level of, for example, greater than appropriately 40% that could be harmful to health or that would create too high an increased risk of combustion in the enclosed space. In sizeable internal spaces such as the interior of a suite of offices the impact of the oxygen dispenser may be restricted to some extent by low capacity of the oxygen dispenser in terms of its oxygen dispensing 10 rate relative to the rate of replenishment of the air by the air conditioning system. For the smaller spaces, however, there is a substantially greater risk of excessive oxygen levels being reached.

In a particularly preferred embodiment of the invention, the air conditioning system of the invention is part of a re-circuiatory air conditioning system for controlling the temperature of air within an enclosed space andlor dehumidifying the air within an enclosed space.

Preferably the system comprises a plurality of oxygen level sensors. Suitably at least one oxygen level sensor is positioned in the enclosed space remote from the oxygen dispenser or upstream of the oxygen dispenser within the line of re20 circulatory flow of air through the air conditioning system.

The capacity andlor number of oxygen concentrators of the air conditioning system of the present invention is suitably chosen to suit the size of space to be air conditioned. For small volumes such as the interior of a car, for example, the oxygen concentrator may be relatively compact and may be adapted to be powered by the battery of the car, for example and possibly via the cigarette lighter.

4 The air conditioning system may have a separate air moving means - fan, pump or the like - to draw air into the oxygen concentrator of the oxygen dispenser from the air moving means for the re-circulatory flow of air through the air conditioning system as a whole. Alternatively, the oxygen dispenser could be configured such that the air moving means responsible for the primary recirculatory flow of air or induction of air into the air conditioning system draws or pushes air into the oxygen concentrator.

Brief Description of the Drawings

A preferred embodiment of the present invention will now be more particularly described, by way of example, with reference to the accompanying drawings, wherein:

Figures 1 and 2 are, respectively a side part sectional view of an oxygen dispenser embodying the first aspect of the present invention; and a schematic diagram illustrating components of a conventional oxygen concentrator.

Description of the Preferred Embodimen

Referring firstly to Figure 2, the conventional oxygen concentrator 1 illustrated here comprises an inner casing 10 within which is housed a compressor 11 to draw in air through the module air inlet 50 and supply it to an oxygen accumulator 12 via sieve beds 13 and filters 14 for particulates. The oxygen enriched air or substantially pure oxygen in the accumulator is then delivered to an outlet 15 of the concentrator 1 via a bacterial filter 16, flow meter 17 and check valve 18. A pressure regulator 19 at the oxygen accumulator 12 maintains the oxygen gas within appropriate pressure levels prior to dispensing of the oxygen.

The oxygen concentrator module 1 receives air flowing through the air conditioning system unit 2, either being air that is continuously recirculated through the air conditioning system unit 2, entering the air conditioning system unit 2 via internal inlet 3; or air freshly inducted from outside of the enclosed space through air inlet vent 4 in the wall of the enclosed space. A pump 5 is illustrated generically as a means for moving the air through the system although its precise position, 5 configuration and mode of operation may vary to suit the needs of the system.

The air that enters the air conditioning system unit 2 is generally conditioned within chamber 6 to, for example, cool the air, dehumidify it andlor filter out contaminants. The thus treated air then passes out via direct outlet duct 7 or via a branch outlet duct 8 that passes through the oxygen dispenser/concentrator module 10 1 to be enriched in oxygen content. The oxygen dispenser 1 comprises the oxygen concentrator of Figure 2 further adapted to incorporate an electronic controller 8 to regulate the operation of the oxygen concentrator in dispensing oxygen enriched air into the airstream from the air conditioning system. The controller 8 may be operated to switch on and off the oxygen concentrator 1 or to open or close a suitably solenoid -o pe rated control valve controlling flow of oxygen enriched air from the concentrator 1 or may be adapted to control in flow of air into the oxygen concentrator 1. The command signals from the controller 8 are generated in response to 20 monitoring of the oxygen level within the enclosed space. Oxygen level sensors 9 are positioned within the roomlspace at strategic locations to obtain an accurate reading of the average oxygen level. Suitably they are dispersed around the room but in the simplest system a single such sensor could be provided at the inlet 3 to avoid the need for extensive wiring or remote communications with the controller 8. 25 These oxygen level sensors 9 continuously or intermittently provide sensory information to the controller 8 which then determines whether the oxygen level 6 within the room has exceeded a maximum safety threshold or is significantly below the desired operating level. The preferred operating range is between 21 % and 25% oxygen. This corresponds to the natural oxygen level of ambient air which is generally 21 %.

The exhaust air/gases from the oxygen concentrator 1 are expelled to the exterior of the enclosed space while the oxygen enriched air is entrained into the conditioned air that passes into the room.

The regulatory system of the present invention ensures that the occupants of the room are provided with optimal levels of oxygen for their own health and for the 10 safety of the environment.

7

Claims

1.

2.

3.

An air conditioning system for an enclosed space which comprises an oxygen dispenser for dispensing substantially pure oxygen or highly oxygenenriched air into the air being conditioned by the air conditioning system, which oxygen dispenser comprises an oxygen concentrator having an activation means or a flow control valve to control directly or indirectly the generation or flow of the oxygen-enriched air from the dispenser, the activation means or flow control valve being under the control of control signals from a controller responsive to oxygen level sensors operatively linked to the controller to sense the level of oxygen in the air of the enclosed space.

An air conditioning system as claimed in Claim 1, wherein the controller is adapted to regulate the oxygen level of the air in the enclosed space within a range of about 21 % to about 40% oxygen content and more preferably to between about 21 % and under about 30%.

An air conditioning system as claimed in Claim 1 or Claim 2 wherein the oxygen dispenser is installed in the air conditioning system in such a way as to receive air that is drawn into the air conditioning system from outside of the confined space and so that the oxygen dispenser can dispense oxygen or oxygen enriched air into the enclosed space but expel oxygen depleted air (particularly nitrogen andlor carbon dioxide gases) externally of the confined space.

8

4. An air conditioning system as claimed in any preceding claim, wherein the air conditioning system is part of a re-circulatory air conditioning system for controlling the temperature of air within an enclosed space andlor dehumidifying the air within an enclosed space.

5. An air conditioning system as claimed in any preceding claim, wherein the system comprises a plurality of oxygen level sensors.

6. An air conditioning system as claimed in any preceding claim, wherein at least one oxygen level sensor is positioned in the enclosed space remote from the oxygen dispenser or upstream of the oxygen dispenser within the line of re-circulatory flow of air through the air conditioning system.

7. An air conditioning system as claimed in Claim 1, wherein the air conditioning system is part of the air condition ing/cli mate control system of a motor vehicle.

8. An air conditioning system as claimed in Claim 7 wherein the oxygen concentrator is powered by the battery of the motor vehicle.

9. An air conditioning system as claimed in any preceding claim, wherein the air conditioning system has a separate air moving means - fan, pump or the like - to draw air into the oxygen concentrator of the oxygen dispenser from the air moving means for the re-circulatory flow of air through the air conditioning system as a whole.

9

10. An air conditioning system as claimed in any of claims 1 to 8, wherein the oxygen dispenser is configured such that the air moving means responsible for the primary recirculatory flow of air or induction of air into the air conditioning system draws or pushes air into the oxygen concentrator.

11. An air conditioning system substantially as hereinbefore described with reference to the accompanying drawings.