GB2537105A

GB2537105A - Air conditioning system

Info

Publication number: GB2537105A
Application number: GB1505406.7A
Authority: GB
Inventors: Mcgowan Gregory
Original assignee: Individual
Current assignee: Individual
Priority date: 2015-03-30
Filing date: 2015-03-30
Publication date: 2016-10-12
Also published as: WO2016156777A1; GB201505406D0

Abstract

An air conditioning system 1 having a housing and comprises a first cooling chamber 5 with an air inlet 11 and air outlet 13 whereby a fan 17 creates a current of air within the first chamber towards a container 15 containing a quantity of refrigerant gas. A pipe 31 extends from the gas container through a wall 9 into a second chamber 7, passing an adjacent defrosting coil 33 before returning into the first chamber and to the gas container. A first valve 25 releases a quantity of gas from the gas container into the pipe when the gas pressure reaches a predetermined level thereby lowering the temperature of the contained gas, and a second valve 45 selectively permits gas to re-enter said gas container to increase the pressure within. The system does not require a compressor and is therefore lighter and less bulky than conventional air conditioners.

Description

Air Conditioning System

Field of the Invention

This invention relates to an air conditioning system.

Background of the Invention

Air conditioning systems are used worldwide to control air temperature, usually in an indoor space such as a home, shop or supermarket. A typical system uses a refrigeration cycle whereby heat is transported from the indoor space to the outside. A circulating refrigerant vapour is compressed by a compressor which raises its temperature. It is then routed through a condensing coil which cools and condenses the vapour into liquid using cool air passing over the coil. The heat is carried away by the air. The liquid is then routed through an expansion valve which reduces the pressure, lowering its temperature, and the colder liquid passes to an evaporator coil. A fan blows the air to be cooled over the evaporator causing the cool refrigerant material to cool further. The warm air is therefore cooled.

Such systems therefore require a gas compressor, making the system relatively bulky and also energy inefficient. The type of refrigerant used is typically a hydro chlorofluorocarbon (HCFC), which substance is relatively expensive and known to contribute to climate change.

It is an aim to provide an improved air conditioning system.

Summary of the Invention

A first aspect of the invention provides an air conditioning system, comprising: a housing having first and second chambers, with an air inlet and air outlet to allow the respective ingress and egress of air to and from the first chamber; a container within the first chamber which contains a quantity of refrigerant gas; a fan or the like for creating in the first chamber a current of air generally towards the gas container; a pipe or series of pipes that extend from the gas container at a first location through a wall into the second chamber, passing adjacent a defrosting means in the second chamber, and returning into the first chamber and to the gas container at a second location; a first valve arranged in use to release a quantity of gas from the gas container into the pipe when the gas pressure reaches a predetermined level thereby to lower the temperature of the contained gas and at least part of the container, and a second valve which selectively permits gas to re-enter said gas container to increase the pressure within.

The refrigerant gas may be refrigerant-grade carbon dioxide, e.g. 002 8744.

The system may further comprise a secondary air cooling unit 20 or coil containing a quantity of refrigerant gel or liquid which is located within the first chamber, adjacent the gas container, between it and the air outlet.

The defrosting means may comprise a fan or the like arranged 25 in use to create in the second chamber a current of air in the direction of the pipe and an extractor outlet.

The defrosting means may further comprise a heater.

The second valve may be arranged so as to permit gas to reenter the gas container when the gas pressure rherewithin reaches a predetermined lower level.

The system may further comprise a gas supply tank for supplying gas to the pipe re-entering the gas container.

The gas container may comprise a plurality of diffuser 5 elements in the region of its second location.

The gas container may comprise a metallic cooling coil element at or near its base.

The system may comprise plural gas containers. Each gas container may have its own pressure release valve and outlet pipe for releasing gas into the common pipe or series of pipes which enter the second chamber. The system may be arranged such that a further valve is provided upstream from the 15 location where the plural outlet pipes join the common pipe or series thereof. The system may be arranged such that the pressure release valves of the containers are selectively controlled so that pressure is released from only a subset of the containers. The system may be arranged such that the pressure release valves and re-entry valves are controlled to release and increase pressure in different containers according to a predetermined order, e.g. using a control system.

A second aspect of the invention provides an air conditioning system, comprising: first and second chambers, the first chamber having an air inlet and outlet, a means of generating an airflow within the first chamber towards the outlet, and, disposed in the first chamber, a cooling element containing refrigerant, which cooling element is connected to a pipe or pipes providing a fluid pathway which extends into the second chamber which is arranged to have, in use, a raised temperature relative to the first chamber, and then back into the first chamber where it extends back to the cooling element, one or more valves being provided in the fluid pathway to control (i) the venting of refrigerant into the fluid pathway and (ii) the input of refrigerant back into the cooling element.

A third aspect of the invention provides an air conditioning system, comprising: a first, cooling chamber; and a second, defrosting chamber, wherein the first chamber comprises a fan for generating an air current towards one or more cooling containers within the first chamber, the or each container being located between the fan and an air outlet of the first chamber and comprising a refrigerant gas the pressure of which is adjustable by means of a control system arranged to detect an upper threshold pressure to effect venting of refrigerant gas to a container outlet, and to detect a lower threshold pressure to effect ingress of refrigerant gas through a container inlet, and wherein a pipe or pipe network extends between the container outlet and intlet, and at least partially through the defrosting chamber, thereby to carry the vented gas into the defrosting chamber which is arranged to have a raised temperature so that in use any solidification of the vented refrigerant gas within the pipe(s) is returned to a gaseous state prior to being returned by the control system to the container through its inlet.

Brief Description of the Drawings

The invention will now be described, by way of non-limiting example, with reference to the accompanying drawings, in 30 which: Figure 1 is side-sectional view of an air conditioning system according to the invention; is a perspective view of a gas container of the system, with the interior visible; is a perspective view of part of an alternative air conditioning system which employs plural gas containers; and Figure 4 is a plan view of the plural cylinders shown in Figure 3, in relation to an air outlet.

Detailed Description of Preferred Embodiments(s)

A first embodiment air conditioning (AC) system 1 is shown in Figure 1. The AC system 1 is shown from the side, fixed to a wall 3, with the room interior to the left-hand side of the wall, and the exterior to the right-hand side. The AC system 1 comprises two distinct chambers, namely a cooling chamber 5 and a defrosting chamber 7. The two chambers 5, 7 are mechanically connected, or integrally formed, but separated by an insulating wall 9.

The cooling chamber 5 comprises separate air inlet and outlet ducts 11, 13. As is conventional, the AC system 1 is fitted to the wall 3 with the inlet duct 11 positioned generally above the outlet duct 13 owing to the fact that cooled air exiting the outlet duct 13 will rise as it gets warmer and some will re-enter the system via the inlet duct 11.

Cooling is primarily effected within the cooling chamber 5 by a primary cooling element, in the form of one or more containers 15, which contain a quantity of refrigerant grade CO2 R744 in gas form. The container(s) 15 are positioned at or near the bottom of the cooling chamber 5, relatively close to the outlet duct 13. In overview, when the gas reaches a predetermined pressure (due primarily to ambient temperature) some gas is vented to pipework which reduces the pressure of the gas in the container 15 and therefore reduces the temperature of the gas. A fan 17 or similar device is Figure 2 Figure 1 Figure 3 positioned adjacent the inlet duct 11 and operates to generate airflow towards the container(s) 15 where it is cooled before leaving the outlet duct 13.

Although not essential, a secondary cooling element 19 is provided between the primary cooling element 15 and the outlet duct 13; this secondary element may be in the form of a coil or similar unit, having gaps or apertures therewithin to allow air to pass through to the outlet duct 13. The secondary element 15 is a sealed unit containing refrigerant liquid or gel, and is positioned very close to the primary element 15 so that it freezes in use by the action of the cooling gas in the container 15, and therefore provides a means of cooling the exiting air even if the gas temperature rises.

Particulate air filters 21, 23 are mounted over the inlet and outlet ducts 11, 13.

Each primary cooling container 15 is a metallic cylinder with 20 an outlet 25 and an inlet 27 for the controlled egress and ingress of gas. The outlet 25 is connected to a discharge pipe 31 via a controllable expansion valve 25, e.g. a pressure control valve (PCV). The expansion valve 25 is controlled electronically to open and close depending on the sensed pressure within the gas cooling container 15. Initially, the gas pressure is assumed to be at a reference level. The gas pressure will be raised by ambient temperature, which will be room temperature in warmer climates, or by the application of heat, e.g. by a heating element or similar source. When the pressure reaches an upper threshold, the expansion valve 25 is opened. When the pressure (or temperature) returns to below another, lower, threshold, the expansion valve 25 is closed. Opening of the expansion valve 25 results in venting of the CO2 gas into the discharge pipe 31. The opening and closing control may be effected according to alternative criteria.

The discharge pipe 31 forms part of a pipework system that 5 passes through the insulating wall 9 into the defrosting chamber 7 as shown. A tight seal surrounds the pipe 31 as it passes through the wall 9. More specifically, the discharge pipe 31 is in fluid communication with, and extends to a defrosting coil 33, which itself connects to a return pipe 35 10 which passes back through the wall 9 into the cooling chamber 5. In use, as vented CO2 gas passes into the defrosting chamber 7, it tends to solidify in a phase-change process called deposition. In order to reverse the phase-change back into gas (sublimation) another fan 37 (which may be associated with a heater) blows warmer air over the defrosting coil 33 and the CO2 gas flows onwards through the return pipe 35.

In the return pipe 35 is a non-return valve 39, e.g. a solenoid-controlled valve, which prevents backflow of gas. A further valve 45 is arranged to controllably return a quantity of the vented gas back into the primary cooling container 15, thereby returning the gas pressure to its prior (i.e. reference) level. At the time the valve 45 is opened, the expansion valve 25 is usually closed.

It will therefore be appreciated, that no compressor of the type employed in conventional air conditioner units is required, allowing the AC system 1 to be lighter, less bulky and more efficient. Here, we take advantage of the falling pressure/temperature effect of venting gaseous refrigerant CO2 which is then defrosted from its solid state and returned in a controlled manner to the previous reference pressure, or thereabouts. The AC system 1 offers particular advantages in warmer climates whereby the ambient temperature will tend to raise the pressure of the gaseous refrigerant CO2 in the gas cooling container 15 to initiate the venting phase.

One or more sensors (not shown) are provided in the gas 5 cooling container 15 to determine in real-time, or near real-time, the current gas pressure. A computer or electronic control system is provided, and is in signal communication with the valves 29, 45 to control the opening and shutting of said valves dependent on the sensed pressure. Alternatively, a separate control system can be provided for each valve 29, 45.

The warm air flow created by the second fan 37 exits the defrosting chamber through a louvered outlet 41 which may have 15 a particulate filter 43.

As shown in Figure 1, a supply tank 36 for the refrigerant CO2 is provided in the defrosting chamber 7 part of the loop, between the non-return valve 39 and the valve 45. Within the tank 36, the refrigerant may be stored for a time as a liquid, possibly for just a short time, but it will convert back into gas before it re-enters the container 15 to top-up the pressure.

Referring to Figure 2, the cooling container 15 comprises a cylindrical metal body 51 having an upper portion 53 which houses the refrigerant CO2 gas, and a base portion 55 within which is arranged a metallic cooling coil 56. The upper end of the body 51 comprises an aperture 57 to which the valve 25 is attached, and the lower inlet 27 is provided close to the base portion 55, which is connected to the return pipe 35. In order to reduce noise that will otherwise tend to occur from gas re-entry through the lower inlet 27, a plurality of vertical diffusers 61 extend from the upper surface of the base portion 55. These serve to diffuse the incoming gas to reduce noise overall. Alternative forms of diffusers can be used.

Referring now to Figures 3 and 4, in another embodiment, multiple such cooling containers 15 can be provided in the cooling chamber 5. These are labelled 15A, B and C, with their respective outlet valves 25, outlet pipes 31, and inlet valves 24 suffixed accordingly. The outlet pipes 31A-C feed to a combining point 65 connected to the common pipe 31'. Similarly, a dividing point 67 splits incoming gas from pipe 35 into three separate inlet pipes which return gas to respective ones of the cooling containers 15A-C. Otherwise, the AC system 1 remains identical to that in Figure 1.

In terms of operation, any combination of the three cooling containers 15A-C can be used. For example, where significant cooling is required, all three can be switched on. Where less cooling is required, just a subset, e.g. the centre container 15B may be switched on. Where cooling to just one side of a room is required, the left or right -hand one may be the only cooling container 15A-C switched on. Where more than one cooling container 15A-C is employed, the control system may operate so that different containers vent in a phased manner, e.g. in the manner of pistons in a car engine, with one venting whilst the other(s) are closed-off and/or receiving feed-back gas.

Figure 4 shows the Figure 3 embodiment from above, indicating 30 the relative positions of the multiple container 15A-C arrangement in relation to the outlet duct 13. It will also be noted that the secondary coil 19 has apertures or slots 70 therewithin to permit airflow to the outlet duct 13.

It will be appreciated that the above described embodiments are purely illustrative and are not limiting on the scope of the invention. Other variations and modifications will be apparent to persons skilled in the art upon reading the 5 present application.

Moreover, the disclosure of the present application should be understood to include any novel features or any novel combination of features either explicitly or implicitly disclosed herein or any generalization thereof and during the prosecution of the present application or of any application derived therefrom, new claims may be formulated to cover any such features and/or combination of such features.

Claims

CLAIMS1. An air conditioning system, comprising: a housing having first and second chambers, with an air 5 inlet and air outlet to allow the respective ingress and egress of air to and from the first chamber; a container within the first chamber which contains a quantity of refrigerant gas; a fan or the like for creating in the first chamber a 10 current of air generally towards the gas container; a pipe or series of pipes that extend from the gas container at a first location through a wall into the second chamber, passing adjacent a defrosting means in the second chamber, and returning into the first chamber and to the gas container at a second location; a first valve arranged in use to release a quantity of gas from the gas container into the pipe when the gas pressure reaches a predetermined level thereby to lower the temperature of the contained gas and at least part of the container, and a second valve which selectively permits gas to re-enter said gas container to increase the pressure within.
2. A system according to claim 1, wherein the refrigerant gas is refrigerant-grade carbon dioxide, e.g. 002 R744. 25
3. A system according to claim 1 or claim 2, further comprising a secondary air cooling unit or coil containing a quantity of refrigerant gel or liquid which is located within the first chamber, adjacent the gas container, between it and the air outlet.
4. A system according to any preceding claim, wherein the defrosting means comprises a fan or the like arranged in use to create in the second chamber a current of air in the direction of the pipe and an extractor outlet.
5. A system according to claim 4, wherein the defrosting 5 means further comprises a heater.
6. A system according to any preceding claim, wherein the second valve is a non-return valve.
7. A system according to any preceding claim, wherein the second valve is arranged so as to permit gas to re-enter the gas container when the gas pressure therewithin reaches a predetermined lower level.
8. A system according to any preceding claim, further comprising a gas supply tank for supplying gas to the pipe reentering the gas container.
9. A system according to any preceding claim, wherein the 20 gas container comprises a plurality of diffuser elements in the region of its second location.
10. A system according to any preceding claim, wherein the gas container comprises a metallic cooling coil element at or 25 near its base.
11. A system according to any preceding claim, comprising plural gas containers.
12. A system according to claim 11, arranged such that each gas container has its own pressure release valve and outlet pipe for releasing gas into the common pipe or series of pipes which enter the second chamber.
13. A system according to claim 12, arranged such that a further valve is provided upstream from the location where the plural outlet pipes join the common pipe or series thereof.
14. A system according to any of claims 11 to 13, arranged such that the pressure release valves of the containers are selectively controlled so that pressure is released from only a subset of the containers.
15. A system according to any of claims 11 to 14, arranged such that the pressure release valves and re-entry valves are controlled to release and increase pressure in different containers according to a predetermined order.17. An air conditioning system, comprising: first and second chambers, the first chamber having an air inlet and outlet, a means of generating an airflow within the first chamber towards the outlet, and, disposed in the first chamber, a cooling element containing refrigerant, which cooling element is connected to a pipe or pipes providing a fluid pathway which extends into the second chamber which is arranged to have, in use, a raised temperature relative to the first chamber, and then back into the first chamber where it extends back to the cooling element, one or more valves being provided in the fluid pathway to control (i) the venting of refrigerant into the fluid pathway and (ii) the input of refrigerant from the fluid pathway back into the cooling element.18. An air conditioning system, comprising: a first, cooling chamber; and a second, defrosting chamber.wherein the first chamber comprises a fan for generating an air current towards one or more cooling containers within the first chamber, the or each container being located between the fan and an air outlet of the first chamber and 5 comprising a refrigerant gas the pressure of which is adjustable by means of a control system arranged to detect an upper threshold pressure to effect venting of refrigerant gas to a container outlet, and to detect a lower threshold pressure to effect ingress of refrigerant gas through a 10 container inlet, and wherein a pipe or pipe network extends between the container outlet and inlet, and at least partially through the defrosting chamber, thereby to carry the vented gas into the defrosting chamber which is arranged to have a raised temperature so that in use any solidification of the vented refrigerant gas within the pipe(s) is returned to a gaseous state prior to being returned by the control system to the container through its inlet.