Patent Description:
Heating systems and cooling systems are known that comprise a fluid circuit through which a fluid circulates under pressure. An example of this type of system is a closed circuit central heating system, in which system water flows in a loop from a boiler, through a series of hot-water radiators, and then back to the boiler.

A problem found with closed circuit systems is that the circulating liquid can become contaminated, resulting in a reduction in the performance efficiency of the heating or cooling system and possibly also leading to total system failure. The most common sources of contaminants in the circulating liquid are: corrosion, lime scale and microbiological growths (bacteria or fungi). Debris and sludge in the circulating liquid of a heating or cooling system can lead to blockages, leakage, and premature system failure.

Approaches to addressing the problem of circulating liquid contamination include flushing of the system to remove any debris in the fluid circuit, and introducing a treatment additive, such as an inhibitor, into circulating liquid for the purpose of preventing or resolving contamination build-up.

Fluid treatment apparatus for treating fluid in a fluid circuit of a heating or cooling system, and a method of treating fluid in a fluid circuit of a heating or cooling system, are disclosed in UK Patent No. <CIT>.

Heating systems and cooling systems are usually manufactured from steel and other common metals, and when these metals come into contact with the circulated fluid, they often corrode. Corrosion in such systems is common and unless the incidence thereof is inhibited or resultant rust or detritus particles removed, system components can become clogged or blocked, which can eventually lead to a severe loss of system efficiency and further deterioration that can result in leaks arising in the system and a total system failure. Thus, corrosion impacts negatively on the efficiency of heating and cooling systems, and causes the primary energy input required to run such systems to increase.

A known practice is to add a corrosion inhibitor into the system water to alleviate the further corrosion of internal parts of system components and materials, and it is industry recommended to add an inhibitor whenever there is a loss of pressure in the system fluid, at which point new, untreated fluid will be introduced into the system to top it up.

The introduction of bacteria, such as Pseudomonas, into a heating system or especially a cooling system via incoming mains fresh water used as a system top-up fluid is another commonly known problem.

These bacteria can and do multiply within the system fluid, resulting in the formation of a 'slime', which can eventually lead to the blocking of internal parts of system components and can result in failures. Thus, the presence of bacteria impacts negatively on the efficiency of heating and cooling systems, and causes the primary energy input required to maintain the original design criteria to increase.

Also, many heating and cooling systems are sealed from the environmental atmosphere and are designed to be at a positive pressure to function properly. During the lifetime of the system, it may be drained for maintenance purposes or may suffer from small leaks of system fluid from the system joints and components. The loss of system fluid will result in a lowering of the designed pressure of the system fluid, resulting in poor system fluid circulation and potential catastrophic failure of some of the system components. Therefore, pressure loss is a critical factor in the efficiency of these types of systems.

<CIT> discloses means for making up, automatically, losses of water from a sealed and pressurised boiler heated water system, which includes a pump for pumping water into the system and timing means to prevent operation of the pump continuously, for more than a predetermined period. <CIT> discloses a modular treatment apparatus configured, in use, to treat a heating and/or cooling system, which comprises two or more modules selected from: (i) a filter module; (ii) a sampling module; (iii) a power flushing module; (iv) a combined sampling and power flushing module; (v) a UV module; and (vi) a dosing module.

According to a first aspect of the invention there is provided a heating or a cooling system comprising a fluid circuit and apparatus to supply a flow of top-up liquid to the fluid circuit of the heating or the cooling system, said apparatus comprising: a liquid reservoir comprising an inlet port connected to a liquid source for supplying the liquid reservoir with a liquid, and an outlet; an outlet port connected to the fluid circuit, and a pump operable to move liquid from said liquid reservoir to said outlet port along a flow path; characterised in that said apparatus further comprises a light source configured to emit ultraviolet light incident on liquid flowing from said liquid reservoir to said outlet port along said flow path.

The light source may comprise one or more lamps configured to emit UV light.

The light source may be configured to emit ultraviolet light incident on liquid flowing from the liquid reservoir to the outlet port at a position along the flow path that is upstream of the pump.

The apparatus may further comprise a dosing valve for connection to an outlet of an additive reservoir such that the dosing valve is operable to supply a flow of an additive from the additive reservoir to liquid flowing from the liquid reservoir to the outlet port along the flow path.

The dosing valve may be configured to supply a flow of an additive from the additive reservoir to liquid flowing from the liquid reservoir to the outlet port along the flow path at a position along the flow path that is downstream of the pump.

The dosing valve may be a proportional dosage valve.

The liquid source may be a cold mains water supply.

According to a second aspect of the invention there is provided a method of supplying a flow of top-up liquid to a fluid circuit of a heating or a cooling system, the heating or a cooling system according to the first aspect, said method comprising the steps of: (a) measuring a pressure level of system liquid in the fluid circuit to obtain a pressure level indication; (b) comparing the pressure level indication obtained at step (a) with a pressure level threshold to determine whether the pressure level indication exceeds the pressure level threshold; and (c) in response to determining at step (b) that the pressure level indication exceeds the pressure level threshold, repeating steps (a) and (b), or (d) in response to determining at step (b) that the pressure level indication does not exceed the pressure level threshold, generating an activation signal to initiate a system filling routine to supply a flow of liquid from the liquid reservoir to the outlet port connected to the fluid circuit, wherein the flow of liquid from the liquid reservoir is treated by ultraviolet light incident thereon before passing through said outlet port.

The method may further comprise the steps of: (e) measuring a pressure level of system liquid in the fluid circuit to obtain a subsequent pressure level indication; (f) comparing the subsequent pressure level indication obtained at step (e) with said pressure level threshold to determine whether the subsequent pressure level indication exceeds the pressure level threshold; and (g) in response to determining at step (f) that the subsequent pressure level indication does not exceed the pressure level threshold, repeating steps (e) and (f), or (h) in response to determining at step (f) that the subsequent pressure level indication exceeds the pressure level threshold, generating a deactivation signal to conclude said system filling routine and repeating steps (a) and (b).

During the system filling routine, a flow of an additive from an additive reservoir may be supplied to the flow of liquid from the liquid reservoir to the outlet port along the flow path.

During the system filling routine, the flow of liquid from the liquid reservoir to the outlet port may be supplied under the operation of the pump, and the flow of an additive is supplied to the flow of liquid from the liquid reservoir to the outlet port at a position along the flow path that is downstream of the pump.

The additive may comprise a corrosion inhibitor.

The liquid reservoir may be connected to a cold mains water supply.

Further particular and preferred aspects of the invention are set out in the accompanying dependent claims.

The present invention will now be more particularly described, with reference to the accompanying drawings, in which:.

Illustrative embodiments and examples are described below in sufficient detail to enable those of ordinary skill in the art to embody and implement the apparatus, systems and/or processes described herein. It is to be understood that embodiments and examples can be provided in many alternate forms and the invention should not be construed as limited to the embodiments and examples set forth herein but by the scope of the appended claims.

A fluid circuit <NUM> of an example heating system <NUM> is shown in <FIG>. The direction of circulating flow of system liquid around the fluid circuit <NUM> is indicated by arrows <NUM>. Heating system <NUM> comprises a heat source <NUM>, such as a boiler, and at least one heat emitter <NUM>, such as a radiator. A main system flow pipe <NUM> extends from the heat source <NUM> to the at least one heat emitter <NUM>, and a main system return pipe <NUM> extends from the at least one heat emitter <NUM> to the heat source <NUM>.

Heating system <NUM> comprises a system pump <NUM>, which is disposed along main system flow pipe <NUM> between the heat source <NUM> and the at least one heat emitter <NUM>, and which is operable to circulate system liquid around the fluid circuit <NUM> in the direction of circulating flow <NUM>. In this illustrated example, heating system <NUM> further comprises an expansion vessel <NUM>, which is disposed along main system return pipe <NUM> between at least one heat emitter <NUM> and the heat source <NUM>.

Apparatus <NUM> is also shown in <FIG>, which is illustrated in further detail in <FIG>.

As will be explained, the apparatus <NUM> is usable to supply a flow of liquid to a fluid circuit of a heating or a cooling system, in particular to supply a flow of top-up liquid to a fluid circuit of a heating or a cooling system.

Apparatus <NUM> is arranged to receive liquid via a fluid conduit I I I that is connected to a liquid source <NUM>, in a direction of inflow <NUM>, and to supply liquid to the fluid circuit <NUM> via a fluid conduit <NUM> that is connected to the main system return pipe <NUM>, in a direction of outflow <NUM>.

The apparatus <NUM> is provided for supplying a flow of liquid to the fluid circuit <NUM> of the heating system <NUM>, in particular for supplying a flow of top-up liquid to the fluid circuit <NUM>.

Features of apparatus <NUM> will now be described in further detail with reference to <FIG>.

Apparatus <NUM> comprises a liquid reservoir <NUM>, which comprises an inlet port <NUM> and an outlet <NUM>. The inlet port <NUM> of the liquid reservoir <NUM> is fluidly connectable to a liquid source for supplying the liquid reservoir <NUM> with a liquid. In the shown arrangement, the liquid reservoir <NUM> is connected to liquid source <NUM> via fluid conduit <NUM>. According to this illustrated embodiment, liquid source <NUM> is a cold mains water supply. The liquid source may however be any suitable alternative source of any suitable alternative liquid. The liquid reservoir <NUM> may be any suitable type, for example a storage tank.

The apparatus <NUM> also comprises an outlet port <NUM> connectable to the fluid circuit <NUM>. In the shown arrangement, the outlet port <NUM> is connected to fluid circuit <NUM> via fluid conduit <NUM>.

Apparatus <NUM> further comprises a pump <NUM>, which is operable to move liquid <NUM> from the liquid reservoir <NUM> to the outlet port <NUM> along a flow path, indicated generally by arrows <NUM> that also indicate the direction of flow. In the shown arrangement, the pump <NUM> is located downstream of the outlet <NUM> of the liquid reservoir <NUM>. The pump <NUM> may be any suitable type.

Advantageously, the apparatus <NUM> further comprises a light source <NUM> configured to emit ultraviolet (UV) light incident on liquid <NUM> flowing from the liquid reservoir <NUM> to the fluid circuit <NUM> along the flow path <NUM>. Thus, liquid <NUM> from the liquid reservoir <NUM> is treated with UV rays before entering the fluid circuit <NUM>. This UV light functions to destroy bacteria present within liquid <NUM> flowing from the liquid reservoir <NUM> before it is introduced into the fluid circuit <NUM>. This ensures that a desired bacteria-free condition of the system water is maintained.

As previously stated, according to this illustrated embodiment, the liquid <NUM> flowing along the flow path <NUM> originates from a cold mains water supply, and the UV beam incident thereon from the light source <NUM> functions to kill bacteria within this fresh water. In this way, bacteria are prevented from entering the system fluid when the fluid circuit <NUM> is being topped-up.

This feature of the apparatus <NUM> is of significant benefit when the temperature of the system fluid is not high enough to kill bacteria through heat alone. For example, bacteria in liquid flowing into a fluid circuit of a heating system in which the system fluid is at a temperature of <NUM> degrees or higher can be destroyed by the heat of the existing system fluid but bacteria in liquid flowing into a fluid circuit of a cooling system in which the system fluid is at a temperature of below <NUM> degrees would not be destroyed in the same way.

According to the shown arrangement, the light source <NUM> is configured to emit ultraviolet light incident on liquid <NUM> flowing from the liquid reservoir <NUM> to the fluid circuit <NUM> at a position along the flow path <NUM> that is upstream of the pump <NUM>. This particular siting of the light source <NUM> serves to inhibit the flow of live bacteria into the pump <NUM>, which hinders bacterial growth on internal surfaces of the pump <NUM>. However, it is to be appreciated that the light source <NUM> may be sited at any suitable location to ensure that liquid <NUM> from the liquid reservoir <NUM> is subjected to UV light emitted therefrom before entering the fluid circuit <NUM>. Thus, the light source <NUM> may be located downstream of the pump <NUM>.

The light source <NUM> may be any suitable light source operable to emit ultraviolet light. The light source <NUM> may comprise only one or more than one UV light emitting lamps, of any suitable type. The light source <NUM> may have any suitable shape and dimensions. The light source <NUM> may be arranged relative to the flow path <NUM> in any suitable way. It is to be appreciated that any physical barrier between a UV light emitting lamp of the light source <NUM> and liquid <NUM> flowing from the liquid reservoir <NUM> will allow an appropriate transmission of the desired light wavelength or wavelengths therethrough. It is hence to be understood that the selection of a material or materials for defining a conduit through which liquid <NUM> can travel from the liquid reservoir <NUM> to the outlet port <NUM> will involve the identification of a material having suitable light transmittance properties.

Beneficially, in this embodiment, the apparatus <NUM> further comprises a dosing valve <NUM> for connection to an outlet <NUM> of an additive reservoir <NUM> such that the dosing valve <NUM> is operable to supply a flow of an additive <NUM> from the additive reservoir <NUM> to liquid <NUM> flowing from the liquid reservoir <NUM> to the outlet port <NUM> along the flow path <NUM>. Thus, liquid <NUM> from the liquid reservoir <NUM> is dosed with an additive before entering the fluid circuit <NUM>. This ensures that a desired additive-concentration condition of the system water is maintained.

As previously stated, according to this illustrated embodiment, the liquid <NUM> flowing along the flow path <NUM> originates from a cold mains water supply, and the dosing valve <NUM> functions to dose this fresh water with the additive <NUM>. In this way, the additive <NUM> is introduced into the liquid <NUM> prior to entering the system fluid when the fluid circuit <NUM> is being topped-up.

This feature of the apparatus <NUM> is of significant benefit when system fluid may be lost through leakage or maintenance draining. For example, introducing an amount of additive <NUM> as liquid <NUM> enters the fluid circuit <NUM> serves to ensure that protection is provided at the earliest stage and also enables an amount of additive <NUM> to be introduced into the existing system fluid to supplement an existing concentration of the additive <NUM> therein.

The dosing valve <NUM> may be any suitable type. In an embodiment, the dosing valve <NUM> is a proportional dosage valve. The additive <NUM> may be any suitable type. In an embodiment, the additive <NUM> is a corrosion inhibitor. According to the shown arrangement, a fluid conduit <NUM>, which in this example is a flexible fluid conduit, extends from the dosing valve <NUM> into the additive <NUM>. The additive reservoir <NUM> may be any suitable type, for example a chemical container.

In the shown arrangement, the dosing valve <NUM> is located downstream of the pump <NUM>. It is to be appreciated however that the dosing valve <NUM> may be sited at any suitable position for introducing the additive <NUM> to liquid <NUM> flowing to the fluid circuit <NUM>.

The apparatus <NUM> further comprises a controller <NUM>. The controller <NUM> is operable to control steps in a method of supplying a flow of top-up liquid to a fluid circuit of a heating or a cooling system. The controller <NUM> may be any suitable device, for example a programmable logic controller (PLC).

Controller <NUM> is configured to receive an input from a pressure sensing arrangement <NUM>, which comprises at least one pressure sensor arranged to sense the pressure of system water within the fluid circuit <NUM>. The or each pressure sensor of the pressure sensing arrangement <NUM> may be of any suitable type and may be located at any suitable position. It is to be appreciated that a pressure sensor of the pressure sensing arrangement <NUM> may be located within the flow path <NUM> or alternatively the fluid circuit <NUM>.

According to this illustrated embodiment, the apparatus <NUM> comprises the pressure sensing arrangement <NUM>, and the pressure sensing arrangement <NUM> comprises a plurality of pressure sensors <NUM>, <NUM>, <NUM>. In this specific example, the pressure sensing arrangement <NUM> comprises a low-pressure transducer/switch <NUM>, a high-pressure transducer/switch <NUM> and a pump pressure transducer/switch <NUM>. As shown, these pressure sensors <NUM>, <NUM>, <NUM> are arranged in series along the flow path <NUM>. In the specific illustrated arrangement, the pressure sensors <NUM>, <NUM>, <NUM> are positioned between the dosing valve <NUM> and the outlet port <NUM>, ordered in the direction of flow from the liquid reservoir <NUM> to the fluid circuit <NUM>.

As indicated, controller <NUM> is also in communication with the pump <NUM> and the light source <NUM>.

Further features of the illustrated embodiment will now be mentioned. An isolation valve <NUM> is disposed between the liquid source <NUM> and the inlet port <NUM>, and a pressurised isolation valve <NUM> is disposed between the outlet port <NUM> and the fluid circuit <NUM>. A non-return valve <NUM> is disposed between the pump <NUM> and the dosing valve <NUM>, to prevent the flow of liquid <NUM> back towards the pump <NUM>. The liquid reservoir <NUM> is provided with a float operated valve <NUM> and an overflow connection <NUM>.

A cabinet <NUM> for housing some or all of the various components of the apparatus <NUM> is also shown. According to the illustrated embodiment, connections to componentry within the cabinet <NUM> are made via fluid conduit I I I (connection between liquid source <NUM> and inlet port <NUM>), fluid conduit <NUM> (connection between fluid circuit <NUM> and outlet port <NUM>) and fluid conduit <NUM> (connection between flow path <NUM> and additive reservoir <NUM>). The use of a cabinet <NUM> provides for convenient introduction of the apparatus <NUM> to a heating or a cooling system. The cabinet <NUM> may be any suitable shape and have any suitable dimensions, and may be fabricated from any suitable material or combination of materials.

Apparatus <NUM> functions to assist system fluid of a fluid circuit of a heating or a cooling system to be maintained at a desired pressure and at a desired extent of dosing.

It is to be appreciated that each of the light source <NUM> and the dosing valve <NUM> of an apparatus <NUM> as described herein will be located, with reference to the illustrated arrangement of <FIG>, upstream of the isolation valve <NUM>, to ensure that top-up liquid supplied by the apparatus <NUM> is treated before being introduced into the fluid circuit <NUM> and equally to ensure that system fluid of the fluid circuit <NUM> is exposed to top-up liquid that has already been treated.

Steps in a method of supplying a flow of top-up liquid to a fluid circuit of a heating or a cooling system will now be described.

A pressure level of system liquid in the fluid circuit is measured to obtain a pressure level indication. This pressure level indication is then compared with a pressure level threshold to determine whether the pressure level indication exceeds the pressure level threshold.

In response to determining, from the comparison, that the pressure level indication exceeds the pressure level threshold, the previous steps of measuring a pressure level of system liquid in the fluid circuit to obtain a pressure level indication and then comparing this pressure level indication with the pressure level threshold to determine whether the pressure level indication exceeds the pressure level threshold are repeated.

In response to determining, from a comparison of a pressure level indication with the pressure level threshold, that the pressure level indication does not exceed the pressure level difference threshold, an activation signal is generated to initiate a system filling routine to supply a flow of liquid from a liquid reservoir to an outlet port connected to the fluid circuit.

Thus, the pressure level of system liquid in the fluid circuit is measured and when a drop in the system liquid pressure is detected, a system filling routine is initiated to restore the system liquid pressure to a desired operating pressure level.

Further steps in the method of supplying a flow of top-up liquid to a fluid circuit of a heating or a cooling system will now be described.

A pressure level of system liquid is then measured to obtain a subsequent pressure level indication. This subsequent pressure level of system liquid is then compared with the pressure level threshold to determine whether the subsequent pressure level indication exceeds the pressure level threshold.

In response to determining, from the comparison, that the subsequent pressure level indication does not exceed the pressure level threshold, the previous steps of measuring a pressure level of system liquid in the fluid circuit to obtain a subsequent pressure level indication and then comparing this subsequent pressure level indication with the pressure level threshold to determine whether the subsequent pressure level indication exceeds the pressure level threshold are repeated.

In response to determining, from a comparison of a subsequent pressure level indication with the pressure level threshold, that the subsequent pressure level indication exceeds the pressure level difference threshold, a deactivation signal is generated to conclude the system filling routine and the previous steps of measuring a pressure level of system liquid in the fluid circuit to obtain a pressure level indication and then comparing this pressure level indication with the pressure level threshold to determine whether the pressure level indication exceeds the pressure level threshold are repeated.

Thus, during the period that the system filling routine is active, the pressure level of system liquid in the fluid circuit is measured and when the desired operating pressure level is again detected, when the system liquid has been properly topped-up, the system filling routine is ceased and monitoring of the pressure level of system liquid in the fluid circuit to detect any drop in the system liquid pressure is again performed.

The flow of liquid from the liquid reservoir during the system filling routine is treated by ultraviolet light incident thereon before entering the fluid circuit. In an embodiment, the flow of liquid from the liquid reservoir is treated by ultraviolet light incident thereon before passing through an outlet port connected to the fluid circuit.

The UV light serves to destroy bacteria within the top-up liquid before it is supplied into the fluid circuit.

In an embodiment, the step of activating the system filling routine involves the controller <NUM> activating the pump <NUM> to begin pumping liquid <NUM> from the liquid reservoir <NUM> and the step of deactivating the system filling routine involves the controller <NUM> deactivating the pump <NUM> to stop pumping liquid <NUM> from the liquid reservoir <NUM>.

In an embodiment, the step of activating the system filling routine involves the controller <NUM> switching on the light source <NUM> to begin emitting UV light, and activating the pump <NUM> to begin pumping liquid <NUM> from the liquid reservoir <NUM> and the step of deactivating the system filling routine involves the controller <NUM> deactivating the pump <NUM> to stop pumping liquid <NUM> from the liquid reservoir <NUM>, and switching off the light source <NUM> to stop emitting UV light.

In an embodiment, alternatively or additionally, during the period that the system filling routine is active, a flow of an additive is supplied to the flow of liquid from the liquid reservoir before entering the fluid circuit. In an embodiment, the flow of liquid from the liquid reservoir is dosed with an additive before passing through an outlet port connected to the fluid circuit.

In an embodiment, the additive is a corrosion inhibitor, which serves to prevent the creation of corrosion particles that may cause damage to the heating or the cooling system.

In an embodiment, during the system filling routine, the flow of liquid from the liquid reservoir to the outlet port connected to the fluid circuit is supplied under the operation of a pump, and the flow of an additive is supplied to the flow of liquid from the liquid reservoir to the outlet port at a position along the flow path that is downstream of the pump.

Thus, in an embodiment, liquid flowing from the liquid reservoir is treated with UV light before entering the pump and is dosed with an additive after exiting the pump.

It is to be appreciated that in an embodiment in which the apparatus <NUM> comprises the light source <NUM> and additionally the dosing valve <NUM> that only the light source <NUM> may be deployed and therefore liquid flowing from the liquid reservoir during a system filling routine may be treated with UV light via the light source <NUM> and optionally also dosed with an additive via the dosing valve <NUM>.

Further it is to be appreciated that in an embodiment, the apparatus <NUM> comprises only the light source <NUM> and not also the dosing valve <NUM>.

Therefore, in a method of supplying a flow of top-up liquid to a fluid circuit of a heating or a cooling system using apparatus as described, a flow of top-up liquid to the fluid circuit may be treated with UV light or treated with UV light and dosed with an additive.

Apparatus for, and a method of, supplying a flow of top-up liquid to a fluid circuit of a heating or a cooling system is disclosed. A system filling routine initiated in response to detection of a drop in a pressure level of system liquid in the fluid circuit is also disclosed. A light source operable to treat the top-up liquid with ultraviolet light prior to entering the fluid circuit, and a dosing valve operable to dose the top-up liquid with an additive prior to entering the fluid circuit are further disclosed.

Claim 1:
A heating or a cooling system (<NUM>) comprising a fluid circuit (<NUM>) and apparatus (<NUM>) to supply a flow of top-up liquid to the fluid circuit (<NUM>) of the heating or the cooling system (<NUM>), said apparatus (<NUM>) comprising:
a liquid reservoir (<NUM>) comprising an inlet port (<NUM>) connected to a liquid source (<NUM>) for supplying the liquid reservoir (<NUM>) with a liquid (<NUM>), and an outlet (<NUM>);
an outlet port (<NUM>) connected to the fluid circuit (<NUM>), and
a pump (<NUM>) operable to move liquid (<NUM>) from said liquid reservoir (<NUM>) to said outlet port (<NUM>) along a flow path (<NUM>); characterised in that
said apparatus (<NUM>) further comprises a light source (<NUM>) operable to emit ultraviolet light incident on liquid (<NUM>) flowing from said liquid reservoir (<NUM>) to said outlet port (<NUM>) along said flow path (<NUM>).