CENTRAL HEATING

Abstract: A central heating reservoir (1) has heated liquid inlets (4) and cooled liquid outlets (5) and is formed for engagement on or about a central heating cylinder (20) such that heat is transferred from liquid passing between the inlets (4) and the outlets (5) to the heating cylinder (20). The reservoir (1) defines a cylinder-receiving cavity (21) that allows for retro fitting to an installed cylinder (20). Independent or interconnected radiator heating circuits are connected between the inlets (4) and the outlets (5) and additional circuits can be easily connected.

Description: CENTRAL HEATING The invention relates to central heating and more particularly to the interaction between a central heating system and a domestic water heating system. Traditionally the interaction between these systems occurs when water heated by a central heating boiler is passed through an internal coil of a domestic water-heating cylinder. The coil allows heat from the central heating system to be transferred to the water stored in the cylinder. There are a number of problems associated with the use of such coils. When this method of heating domestic water is used the delays can be excessive. This is true even when zone isolation techniques are employed. Additionally, retrofitting coils of this type to existing cylinders is not possible as the cylinders are of necessity sealed. Furthermore, the number of central heating circuits which can be efficiently connected to the coil is limited. There is therefore a need for a central heating system, which will overcome the aforementioned problems. Accordingly, there is provided a central heating reservoir of the type having a heated liquid inlet and a cooled liquid outlet, the reservoir being formed for engagement on or about a heating cylinder such that heat is transferred from liquid passing between the inlet and outlet to the heating cylinder. In this way water or oil based heat carriers can be passed around the cylinder so that heat is efficiently transferred to the cylinder. As the reservoir is designed to engage on an exterior surface of the cylinder the system can be easily fitted to existing systems. Preferably, the central heating reservoir defines a cavity for receiving the cylinder. In this way the cylinder can be snugly mounted within the cavity and securely held in position. Heat is transferred from the reservoir to the cylinder about the entire contact surface, this increased contact area greatly enhances the efficiency of heat transfer. This will reduce the time required to heat the water in the cylinder thus improving responsiveness of the water heating system. Preferably, the reservoir is formed as a hollow U-Section shell structure. Forming the reservoir as a shell structure results in a light component part that can be easily installed or removed. Ideally, the water heating system is provided as a one-piece unit. This reduces the overall number of parts and allows for ease of manufacture and installation inherently reducing the overall cost of the product. In one embodiment, a heat transferring facilitator is interposed between the reservoir and the cylinder. This allows for expansion of the component parts and reduces the risk of welding between the cylinder and the reservoir due to high temperatures while providing insulation of the water-heating cylinder to prevent reverse heat transfer. In one embodiment, the facilitator is provided by sand. Ideally, the reservoir is manufactured from stainless steel, copper or aluminum thereby providing the necessary heat transfer characteristic while also delivering the strength and rigidity required. Ideally, the reservoir is provided as a cylinder-housing jacket. Preferably, the liquid is pumped within the jacket between the inlet and the outlet. In a further embodiment, the hot water circulates due to convection. According to another aspect of the invention there is provided a central heating reservoir having a plurality of heated liquid inlets and a plurality of cooled liquid outlets, the reservoir being formed for engagement on or about a heating cylinder such that heat is transferred from liquid passing between the inlets and outlets to the heating cylinder. In this way water or oil based heat carriers can be passed around the cylinder so that heat is efficiently transferred to the cylinder. As the reservoir is designed to engage on an exterior surface of the cylinder the system can be easily fitted to existing systems. Ideally, the reservoir is adaptable for use in conjunction with one or more boilers. Preferably, the reservoir incorporates means for connection to a plurality of independent or interconnected radiator circuits. In one arrangement the reservoir incorporates an anti vacuum valve. Preferably, the reservoir includes a safety release valve to prevent accidental damage to the system. Preferably, the reservoir also includes an automatic air vent. According to one aspect of the invention, there is provided a central heating system incorporating a boiler, a pump and a central heating reservoir. Preferably, the reservoir has one or more heated liquid inlets and one or more cooled liquid outlets. Ideally, the reservoir has a radiator flow tapping and a radiator return tapping. Ideally, the reservoir is adaptable for use in conjunction with one or more boilers. Preferably, the reservoir incorporates means for connection to a plurality of independent or interconnected radiator circuits. In one arrangement the reservoir incorporates an anti vacuum valve. Preferably, the reservoir includes a safety release valve to prevent accidental damage to the system. Preferably, the reservoir also includes an automatic air vent. The provision of a central heating system reservoir ensures that a larger volume of water is available in the overall system, the temperature throughout is thus balanced and the risk of air being drawn into the system during unnecessary venting caused by inaccurate temperature readings is eliminated. The system reduces water oxygen content throughout the system as air is not drawn in and agitation of water in the system is eliminated. The reservoir also reduces pressure in the system and eliminates the risk of pitching associated with the pressure on the water as it passes through the coil. It is an important feature of the invention that the reservoir can be connected to a number of independent or interconnected radiator circuits by the simple addition or blocking of inlet and outlet tapping combinations. The system thus overcomes reconfiguration or augmentation problems by the relatively simple expedient of allowing additional circuits to be added. According to another aspect of the invention, the system incorporates a pump controller the controller being operatively connected to the pump and being formed for gradually ramping the pump up to and down from operating speed to enhance system stability. In one arrangement the controller has a large proportional control term. In another arrangement, the controller incorporates an inverter arrangement to control operating frequency. According to a further another aspect of the invention the system incorporates an aperture controller for opening and closing an inlet and or an outlet of a coil of a domestic water cylinder. Beneficially, this enhances system stability and prevents pitching associated with pressure in the coil. The invention will hereinafter be more particularly described with reference to the accompanying drawings, which show by way of example only, one embodiment of central heating reservoir according to the invention. In the drawings: - Fig. 1 is an elevation view of a central heating reservoir in accordance with the invention; Fig. 2 is a plan view of the central heating reservoir of Fig. 1; Fig. 3 is a view of the central heating reservoir of Fig. 1 in combination with a water-heating cylinder; Fig. 4 is a plan view of a water heating system as shown in Fig. 3; Fig. 5 is an elevation view of an alternative central heating reservoir in accordance with the invention; and Fig. 6 is an elevation view of an alternative central heating system in accordance with the invention; Fig. 7 is a plan view of the central heating reservoir of Fig. 6; Fig. 8 is a schematic view of a central heating system in accordance with the invention; and Fig. 9 is a perspective view of a central heating system reservoir in accordance with another aspect of the invention. Referring to the drawings and initially to Figs. 1 and 2 there is shown a central heating reservoir in accordance with the invention indicated generally by the reference numeral 1. The reservoir 1 has two heated liquid inlets 4 and two cooled liquid outlets 5, the reservoir 1 being formed for engagement on or about a central heating cylinder 20 such that heat is transferred from liquid passing between the inlets 4 and the outlets 5 to the heating cylinder 20. The reservoir 1 defines a cylinder-receiving cavity 21 between a hollow base 2 and a connected upstanding liquid carrying sidewall 3 on the base 2. The sidewall 3 is terminated in an annular top section 6 away from the base 2, the top section carrying an anti vacuum valve 7, a safety valve 8 and an automatic air vent 9. In use, hot water from a standard boiler system (not shown) is pumped or gravity fed via the inlets 4 through the reservoir 1 to the outlets 5. Liquid emerging from the outlets 5 can then be routed into domestic radiator circuits (not shown) supplying heating for a house. Referring now to Figs. 3 and 4 there is shown a water heating system in accordance with the invention indicated generally by the reference numeral 100. The water heating system 100 has the reservoir 1 connected and carrying a water-heating cylinder 20. The cylinder 20 fills the cavity 21 to ensure a maximum contact area between the reservoir 1 and the cylinder 20. In use, hot water is pumped through the water inlets 4 and circulates within the reservoir 1. Heat is transferred through the wall of the reservoir 1 to the contact surface of the cylinder 20 thereby heating the water in the cylinder 20 from locations around the entire surface area of the cylinder. Hot water from the reservoir 1 is tapped off to radiator circuits through the outlets 5. Referring now to Fig. 5 there is shown another embodiment of a water heating system in accordance with the invention indicated generally by the reference numeral 500. In this arrangement a heat transferring facilitator 501 is interposed between the reservoir 1 and the cylinder 20. This allows for expansion of the component parts and reduces the risk of welding between the cylinder and the reservoir due to high temperatures while providing insulation of the water-heating cylinder to prevent reverse heat transfer. Referring now to Figs. 6 and 7 there is shown an alternative central heating system in accordance with the invention indicated generally by the reference numeral 600. The system 600 has a reservoir 601 and a domestic water cylinder 620. The central heating reservoir 601 has heated liquid inlet tappings 610, 611, 612 and 613 and cooled liquid outlet tappings 614, 615, 616 and 617. The reservoir 601 is formed with a U shaped section to define a cavity for engagement on and about the heating cylinder 620 such that heat is transferred from liquid passing between the inlet tappings 610, 611, 612, 613 and the outlet tappings 614, 615, 616 and 617 to the heating cylinder 620. The reservoir 1 may optionally be fitted with a heat exchanger shown as 603 and with an electric immersion heater 604. Heated water from the system 600 is drawn from the hot water outlet 605 and is supplied from the cold water inlet 606. As illustrated in previous embodiments this system has a safety valve 607 an automatic air vent or open vent 608 and an anti vacuum valve 609. When the system is not used to heat water in the cylinder 620 this may be achieved using a conventional immersion 618. It is an important feature of the current invention that the reservoir is adaptable for use in conjunction with one or more boilers. This can be achieved by connecting additional tappings to the reservoir. It is also an important feature of the invention that the reservoir incorporates means for connection to a plurality of independent or interconnected radiator circuits by way of inlet and outlet tapping combinations. It will be understood that the invention is not limited to the U section shape of reservoir described and that it may equally be implemented with a base providing a seat for the cylinder. Similarly it will be appreciated that the reservoir may fully enclose the cylinder as a sealed unit. Depending on system requirement the reservoir may also be equipped with a variety of heating devices either interactively connected to a cylinder immersion or acting independently. Referring now to Fig. 8 there is shown a central heating system in accordance with the invention indicated generally by the reference numeral 801. The system 801 has a boiler 802 connected to a coil inlet 803 of an indirect cylinder 804 on an outward circuit indicated generally at 805. The outward circuit 805 also has an expansion tank 806. A return circuit indicated generally at 807 connects a coil outlet 808 to the boiler 802 through a pump 809 and a central heating system reservoir 810. In more detail and referring now to Fig. 9 the reservoir 810 has an inlet 811 for receiving water from the cylinder 804 and an outlet 812 for delivering water from the reservoir 810 to the pump 809. The reservoir 810 has two radiator flow tappings 814, 815 and two radiator return tappings 816, 817. In use, water heated by the boiler 802 is pumped under pressure from the pump 809 on the outward circuit 805 to the inlet 803 and through the cylinder 804. This uses water heated by the central heating system 801 to heat domestic water in the same way as known systems operate. The water then passes through the coil to the outlet 808 and to the reservoir inlet 811. The water in the reservoir 810 is thus heated and cooled water is drawn from the outlet 812 back through the pump 809 to the boiler 802. The provision of a central heating system reservoir 810 in this way has a number of distinct advantages and technical improvements over known systems. By providing a larger volume of water in the overall system the temperature throughout is balanced, thus eliminating the risk of air being drawn into the system during unnecessary venting occasioned by inaccurate temperature readings. In operation, the system reduces the oxygen content of the water in the system as there air is not drawn in and agitation of water in the system is eliminated. The provision of the central heating system reservoir 810 also reduces pressure in the system and eliminates the risk of pitching associated with the pressure on the water as it passes through the coil of the cylinder 804 between the inlet 803 and the outlet 808. In the embodiment described the central heating system reservoir 810 draws heated water from each of the radiator flow tappings 814 and 815. This heated water is passed trough a series of radiator circuits (not shown) before being returned to the radiator return tappings 16 and 17 respectively. It is an important feature of the current invention that the reservoir is adaptable for use in conjunction with one or more boilers. This can be achieved by connecting additional tappings to the reservoir. It is also an important feature of the invention that the reservoir incorporates means for connection to a plurality of independent or interconnected radiator circuits by way of inlet and outlet tapping combinations. The system overcomes the reconfiguration or addition problems described by the relatively simple expedient of allowing additional circuits to be added by addition of radiator flow and radiator return tapping combinations. According to one aspect of the invention, the system incorporates a pump controller (not shown). The controller operates to gradually ramp the pump up to operating speed rather than allowing the impulse associated with full power to throw the system into instability. The controller also operates to reduce the speed in the same way thus improving overall system stability. The controller may optionally use a large proportional control term or an inverter arrangement to control operating frequency. According to another aspect of the invention the system incorporates an aperture controller for opening and closing the inlet 803 and the outlet 808. This further enhances system stability and prevents pitching associated with pressure in the coil. By way of an illustrative example of the ability of the system to reduce oxygen from water in the system was conducted and is now described. Apparatus The system illustrated in Fig. 8 was filled with 140.8 litres of water. The working head of the expansion tank was 2.44 meters high. The distance between the boiler and cylinder was 0.915 meters. A dissolved Oxygen test on a sample of water from the reservoir on itialisation yielded 5.7 mg/1. The boiler was then set at a temperature of 65 degrees Celsius and the speed of the pump was reduced the lowest setting. The system was operated for 27 hours over five days. Day 1 3 hrs. Day 2 5 hrs. Day 3 9 y 2 hrs Day 4 5 hrs On day six the dissolved oxygen test was repeated and yielded l.lmg/1. It will be understood that the reservoir described above may equally be connected to an underfloor heating system. It will also be understood that the a number of reservoirs may be connected in the context of an overall system. For example, one reservoir may be used with an underfloor heating system and another used for radiator circuits. It is to be understood that the invention is not limited to specific details described herein which are given by way of example only and that various modifications and alterations are possible without departing from the scope of the invention.

Claims: CLAIMS: 1. A central heating reservoir of the type having a heated liquid inlet and a cooled liquid outlet, the reservoir being formed for engagement on or about a heating cylinder such that heat is transferred from liquid passing between the inlet and outlet to the heating cylinder. 2. A central heating reservoir as claimed in claim 1 in which a U-shaped section defining a cavity for receiving the cylinder provides the central heating reservoir. 3. A central heating reservoir as claimed in claim 1 or claim 2 and in which a heat transfer facilitator is interposed between the reservoir and the cylinder. 4. A central heating reservoir as claimed in any preceding claim incorporating means for operative connection with a plurality of central heating boilers. 5. A central heating reservoir as claimed in any preceding claim having a plurality of heated liquid inlets and a plurality of cooled liquid outlets. 6. A central heating reservoir as claimed in claim 5 in which the reservoir incorporates means for connection to a plurality of radiator circuits. 7. A central heating reservoir as claimed in any preceding claim incorporating safety release means. 8. A central heating system incorporating a boiler, a pump and a central heating reservoir, the reservoir having a heated liquid inlet, a cooled liquid outlet, a radiator flow tapping and a radiator return tapping. 9. A central heating system as claimed in claim 8 in which the reservoir is formed for use with one or more central heating boilers. 10. A central heating reservoir as claimed in claim 8 or claim 9 in which the reservoir incorporates means for connection to a plurality of radiator circuits. 11. A central heating system as claimed in any of claims 8 to 10 incorporating a pump controller the controller being operatively connected to the pump and being formed for gradually ramping the pump up to and down from operating speed to enhance system stability. 12. A central heating system as claimed in claim 11 wherein the controller has a large proportional control term. 13. A central heating system as claimed in claim 11 or 12 wherein the controller incorporates an inverter arrangement to control operating frequency. 14. A central heating system as claimed in any of claims 8 to 13 incorporating an aperture controller for opening and closing an inlet and or an outlet of a coil of a domestic water cylinder.

Inventors: CREMIN TIMOTHY, CREMIN, TIMOTHY
Applicants: CREMIN TIMOTHY, CREMIN, TIMOTHY
Application year: 2000
Main classification: F24D3
IPC codes: F24D3