GB2505910A

GB2505910A - Thermostatically controlling water flow through a central heating system having at least one radiator

Info

Publication number: GB2505910A
Application number: GB1216416.6A
Authority: GB
Inventors: Alan Rodney Henderson
Original assignee: IPOCAUST Ltd
Current assignee: IPOCAUST Ltd
Priority date: 2012-09-14
Filing date: 2012-09-14
Publication date: 2014-03-19
Also published as: GB201216416D0

Abstract

A central heating system 401 has at least one radiator supplied with a flow of water, the flow preferably being heated by a condensing boiler 402 of the system. A device 404 is arranged to restrict the flow of water through the at least one radiator when the temperature of water flowing through the radiator exceeds a predetermined temperature. Where multiple radiators are present across a plurality of rooms 403A-D, the device preferably includes a plurality of inlets, with each inlet corresponding to a respective room. The device may restrict the flow of water through each inlet by way of a cam acting upon a follower (506A-D, figure 5). Each inlet can be closed if the temperature of water at that inlet exceeds the predetermined temperature, and therefore the radiator(s) associated with the room of that inlet. The temperature may be determined by an electronic temperature sensor (509A-D, figure 5) or a temperature-sensitive wax element. The device may include a common outlet (505, figure 5) that feeds return water to the boiler. The system can be used to ensure that boiler return water is at a temperature suitable for the boiler to run in a condensing mode, thereby improving efficiency.

Description

Controlled Heating System

CROSS REFERENCE TO RELATED APPLICATIONS

This application represents the first application for a patent directed towards the invention and the subject matter.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a central heating system for controlling the flow of water and a method of controlling the flow of water in such a central heating system.

2. Description of the Related Art

Standard central heating systems are known to operate at around 75% efficiency. An alternative to these systems which aims to improve the efficiency involves the, use of condensing boilers which have the potential to operate at around 98% efficiency.

In practice, condensing boilers in radiator systems rarely achieve this value as they are dependent on the temperature in the return flow of the heating system. Condensing boilers extract the latent heat of condensation, however, the boiler will not condense if the return flow temperature rises above its condensing temperature. Thus, when used in conventional radiator systems, the system only operates at full condensing efficiency for a limited period of the heating cycle, that is, when the return temperature is below a given temperature i.e. in the warming up period of the system. The overall effect is that the efficiency drops below its full potential.

Alternative proposals include the use of lower temperature radiators in the system by utilising much larger radiators. However, in practice, these are not practical and there remains a need to ensure the return temperature in such a system is kept below a given temperature to provide a more efficient heating system.

Thus, there remains a desire to improve the overall efficiency and viability of current heating systems which utilise condensing boilers by addressing these problems.

BRIEF SUMMARY OF THE INVENTION

According to an aspect of the present invention, there is provided apparatus for controlling the flow of water in a central heating system comprising: at least one radiator; and a device for restricting the flow of water through said central heating system; wherein said device retains the flow of water in said at least one radiator when the temperature of said flow of water through said radiator is above a predetermined temperature.

According to a further aspect of the present invention, there is provided a method of controlling the flow of water in a central heating system comprising at least one radiator and comprising the steps of: filling a device for restricting the flow of water in said central heating system; and retaining the flow of water in said at least one radiator when the temperature of said flow of water through said radiator is above a predetermined temperature.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 shows a typical scenario in a building utilising a central heating system; Figure 2 shows a control device capable of sending the temperature of the water flow through a central heating system; Figure 3 shows the control device of Figure 2 in a closed position; Figure 4 shows a schematic diagram of a central heating system; Figure 5 shows an example embodiment of a single cam arrangement for a control device which may be utilised in the present invention; Figure 6A shows a cross sectional view of a four zone multiport control device; Figure 6B shows an alternative cross sectional view of a four zone multipart control device; and Figure 7 shows a flow chart describing the operation of the control system for the control device described herein.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

Figure 1 A typical scenario in a building utilising a central heating system is shown in Figure 1. Figure 1 shows a zone or room, indicated generally by the numeral 101 which includes a radiator 102 which is configured to emit heat to the surrounding area of room 101 thereby providing warmth to user 103. In this example embodiment, zone 101 is a single room comprising a single radiator 102. However, it is appreciated that a zone may comprise seeraI rooms with either a single radiator or a plurality of radiators which are substantially similar to radiator 102 and which also emit heat to user 103. In one embodiment, zone 101 comprises a single room with a plurality of radiators for example.

Radiator 102 is connected to any conventional type central heating system which typically includes heat emitters, such as radiator 102, and a boiler, as illustrated in the example shown in Figure 4.

Figure 2 Figure 2 shows a control device 201 capable of sensing the temperature of the water flow. In a preferred embodiment, control device 201 is used in a central heating system comprising a single zone with a single radiator. Alternatively, the control device 201 can be used in the alternative system as shown in Figure 4.

Control device 201 includes a temperature sensitive device 202 enclosing a temperature sensitive wax capsule which is responsive to a predetermined temperature. Control device 201 further comprises an actuator 203 and a piston 204. The actuator 203 is connected to piston 204 such that as the water temperature increases, the wax capsule in the temperature sensitive device 202 expands and the actuator 203 pushes on piston 204 such that spring 205 is compressed.

In the example shown in Figure 2, control device 201 is shown in an open position, such that a water flow through the device (as indicated by the arrows 206) can pass from an inlet port 207 to an outlet port 208. Thus, the water flow entering the inlet port 207 is the water from a radiator or zone on its return back to the boiler and the temperature of this water flow dictates the expansion of the temperature sensitive wax capsule 202 in the control device 201.

In an embodiment, control device 201 is constructed so that it is fitted on to the outlet connection of the radiator. The wax capsule of the control device 201 is also positioned inside the radiator enabling the actual return water flow temperature to be monitored effectively.

In the open position of Figure 2, the control device 201 is operating at a temperature below a predetermined temperature such that water is permitted to flow through the control device 201. The temperature sensitive wax capsule is responsive to the predetermined temperature such that control device 201 closes when the temperature is above this predetermined value, as is shown in Figure 3.

Figure 3 Control device 201 is shown further in Figure 3 in the closed position.

As described previously in Figure 2, control device 201 comprises a temperature sensitive device 202 including a wax capsule contained therein for monitoring the temperature of the water flow. The wax capsule is temperature sensitive and is responsive to a predetermined temperature. The wax capsule is connected to an actuator 203 which is in turn connected to piston 204.

As shown in Figure 3, the actuator 203 has moved as the wax capsule has expanded in response to a change in water temperature. Thus, spring 205 has been compressed and piston 204 has moved so as to close control device 201 With the increased volume created by the expansion of the wax capsule, the piston 203 abuts against housing 301 thus preventing water flow between the inlet 207 and outlet 208. The water can then be maintained in position in each of the plurality of zones or, more specifically, in any one of the radiators in each of the plurality of zones until the temperature drops below the predetermined temperature. The closure of control device 201 is assisted by means of a sealing ring 302. The temperature is thus monitored by means of the wax capsule which responds to a reduction in temperature by contracting, thus reopening control device 201 and returning to the position as shown in Figure 2.

In an embodiment, the predetermined temperature is configured to be compatible with operating temperatures of condensing boilers and is set to ensure return temperatures below 55°C. It is appreciated that, subject to operational requirements, the predetermined temperature may be any other suitable temperature for the central heating system in question.

Control device 201 is suitable for installation in a central heating system comprising a single radiator or a central heating system with a plurality of radiators. When a plurality of radiators is present, however, a plurality of control devices substantially similar to control device 201 would be positioned in each individual radiator to enable control over each individual zone and each individual radiator.

In a preferred embodiment, control device 201 is fitted in the discharge pipe on a radiator and operates as described. In an alternative embodiment, the control valve further comprises an isolating or balancing valve substantially similar to the type conventionally used on radiator discharge pipes. This allows further control of the heating rates of each of the radiators.

In further embodiment, the control device also includes a room temperature control mechanism similar to the type used on conventional thermostatic radiator valves to allow room temperatures in particular zones to be specified. The system may also include a remote control enabling the temperature to respond to a time sequence. In one embodiment of this type, the remote control system further includes an electronic temperature sensor which allows the control device to be shut off completely if required (and reopened after a specified period as required).

Figure 4 A schematic diagram of a central heating system in accordance with that previously discussed in Figure 1, is shown in Figure 4. Central heating system 401 is an example of a zoned heating system and comprises a boiler 402 and a plurality of zones 4014, 403B, 403C, and 403D. Each zone 403 relates to a particular area, zone or room of a property or a building which requires heating. This would typically include a room such as room 101 as shown in Figure 1. In an example embodiment, 403A is a living room, 4036 is a bedroom, 403C is a bathroom and 403D is a study area.

Each of the zones 403 includes at least one heat emitter for providing warmth to the zone, such as radiator 102 or similar. Each one of the plurality of zones 403 receives water from a boiler 402 which is used to heat the zones to the temperature requested by a user. The water is then configured to flow back into the boiler 402 and circulates around the heating system as required and indicated by the arrows shown in Figure 4.

Central heating system 401 further comprises a control device 404 which restricts the flow of water through the central heating system 401.

Device 404 is configured to retain the flow of water in at least one of the radiators in any one of the plurality of zones 403 when the temperature of the flow of water through any given radiator is above a predetermined temperature.

It is appreciated that while the central heating system 401 as shown in Figure 4 shows four separate zones 403, an alternative number of zones may be present in alternative central heating systems. For example, in an alternative embodiment, the central heating system comprises a single zone which receives a flow of water from the boiler and outputs a flow of water to the control-device before returning the flow of water back to the boiler. The single zone includes a single radiator and may be substantially similar to the room shown in Figure 1; however, it is appreciated that a plurality of radiators may also be present. Similarly, it is appreciated that the single zone may be substantially similar to any one of zones ito 4 shown in Figure 4.

In the illustrated embodiment of Figure 4, control device 404 is positioned in the return flow of central heating system 401 and configured to control the water flow return to the boiler 402 from the individual zones. Control device 404 is also configured to remain closed to retain the water of the water flow in the individual zoned areas when the temperature of the water is above a predetermined temperature.

In an embodiment, the boiler 402 is a condensing boiler which utilises a system which extracts the latent heat of condensation to provide maximum efficiency. A condensing boiler of this type operates at an optimum efficiency when the return temperature is below 55°C. In a particular embodiment, the temperature at which the control device 404 is configured to close at is set to 55°C such that flow through control device 404 is permitted only when the temperature is below this figure. Consequently, when the temperature rises above this predetermined temperature, flow is prevented through the control device.

Figure 5 Figure 5 shows an example embodiment of a single cam arrangement for a control device 501 which may be utilised in the present invention, and covered substantially in the Applicant's co-pending British patent application.

The cam arrangement shown comprises a single cam 502 positioned in a housing 503. Control device 501 comprises a plurality of distribution ports 504A, 504B, 504C and 504D and a shared port 505. Each of the distribution ports 504 correspond to one of a plurality of zones, such as the zones described previously in Figure 4.

Control device 501 as shown in Figure 5 corresponds to a central heating system which includes four separate zones and thus indicates four distribution ports 504, each distribution port corresponding to one of the plurahty of zones. For example, it can be seen that distribution port 504A could correspond to zone 403A shown in Figure 4 and1 similarly, zone 403B could correspond to distribution port 504B and so on.

Shared port 505 is configured to receive a flow of water from each of the distribution ports 504 such that the flow of water in a central heating system flows between the plurality of distribution pods and the shared port 505. Control device 501 is configured to restrict flow through each of the distribution ports 504 such that flow can be prevented to any number of these zones. Specifically, control device 501 is configured such that a flow through distribution port 504 can be either permitted or prevented, irrespective of whether flow is flowing through any of the other distribution pods 504B, 504C or 504D. In contrast, shared port 505 remains open to permit a flow whenever one enters the control device.

In the embodiment shown, each of the distribution ports are fed water from a particular zone in the central heating system such that the water flows from these ports.to the shared port 505 and thus returns to the boiler. The control device is positioned in the return flow which enables the temperatures in the return flow to be monitored easily and advantageously allows the monitoring system (including the appropriate sensors) to be integrated into the control device itself. This in turn allows for a more compact control device to be used in the system.

The flow through each of the distribution ports 504 is restricted, by means of the cam 502 which operates a plurality of cam followers, indicated at 506A, 506B, 506C and 5060. The cam followers 506 are each configured to activate a valve positioned in each of the distribution ports.

Cam 502 is, in this embodiment, a single cam comprising a plurality of high profile sections, such as high profile section 507 and a plurality of low profile sections such as low profile section 508. The high profile sections and low profile sections are configured to open and close the distribution ports 504 such that, as the cam 502 rotates, the high profile sections push the cam followers 506 away from the centre of cam 502 and the low profile sections allow the cam followers 506 to retract towards the centre of cam 502.

In this illustrated embodiment, the number of distribution ports is four which corresponds to a four zone central heating system. In an alternative embodiment, the number of distribution ports is three which corresponds to a three zone central heating system. In a further embodiment1 the number of distribution ports is two, thus corresponding to a two zone central heating system, such as the example referred to previously of a zoned heating system whereby the zones correspond to the upstairs and the downstairs of a building.

In further embodiments, the number of distribution ports is increased with increase of zones required.

Each of the distribution pods 504 includes a temperature sensing device 509 which are configured to monitor the temperature in each of the distribution ports. Shared port 505 also includes a temperature sensing device 510 which is configured to monitor the return temperature in shared port 5D5.

In an embodiment, the temperature sensing devices are electrical sensors.

The distribution pods as shown can be considered as being arranged in two pairs. A first pair comprising distribution port 504A and distribution port 504C are arranged 135°C apart. Similarly, a second pair comprising distribution pod 504B and distribution port 504D are also arranged 135°C apart. From a central point indicated at 511 and moving in an anticlockwise direction around the cam, the distribution ports are arranged around cam 502 at intervals of 22.5°C, 112.5°C, 247.5°C, and 337.5°C. The nature of this geometric arrangement allows for the distribution ports to be arranged in the embodiment shown in Figures GA and 6B.

Figures 6A & 6B Figures 6A and 6B each show cross sectional views of a four port control device in accordance with an aspect of the present invention. In the embodiment shown in Figures GA and GB, the distribution ports have been adjusted from the embodiment shown in Figure 5 to provide an improved and compact control device which functions under the same principles. Figure 6A shows a cross sectional view when viewed from above the device and Figure 6B shows a cross sectional view from the side of the device. The four port control device (or valve) is substantially similar to that described in the Applicant's co-pending British patent application for a Control Device.

Control device 601 comprises a plurality of distribution ports 602 whereby each distribution port 502 corresponds to one of the plurality of zones such as the zones shown in Figure 4. Control device 601 further comprises a shared port 603 and the flow of water is configured to flow from the plurality of distribution ports 602 to the shared port 603. Control device 601 is configured to restrict flow through each of the distribution ports 602 such that flow can be prevented to any number or all of these zones.

In this illustrated example, control device 601 controls four separate zones of a zoned heating system with the return flow from each of the central heating system zones configured to enter the device at each of the distribution ports 602. The device is further configured to discharge the common flow at shared port 603.

As shown in Figures 6A and 6B, temperature sensors are positioned in each of the distribution ports 602, and indicated by the numeral 604. The temperature sensors 604 monitor the return temperature in each of the zones.

Similarly the common return temperature is monitored by a further temperature sensor 605, positioned in shared port 603. The control device further includes a double cam 606, which is configured to open or close any one of the distribution ports 602 independently of each other. Cam 606 also provides the means by which flow can be restricted through each of the distribution ports 602 such that flow to all zones can be permitted.

With reference to the alternative cross sectional view shown in Figure 6B, control device 601 further comprises a printed circuit board (PCB) 607 and an actuator motor 608.

The distribution ports 602 are configured to include temperature sensing devices for monitoring the temperature of water flow through their respective distribution ports 602. In one embodiment, the temperature sensing device is an electrical temperature sensor 604 which records the temperature of the water flow through the distribution ports 602. In a preferred embodiment, each of the distribution ports, as well as the shared port, include a temperature sensor of this type such. that the temperature of the water flow can be recorded from each of the distribution ports and the shared port to determine whether any of the distribution ports should remain open or closed.

Any such temperature sensors positioned in the distribution ports or the shared port are connected to the printed circuit board (PCB) 607 which is enabled to maintain a record of temperature and signal to adjust the cam 606 in order to control the opening and closing of the distribution ports via the actuator motor 608. The process showing of the opening and closing of the ports is described in detail in Figure 7.

In an embodiment, the temperature in the shared port 603 is monitored primarily and, if an indication is received that the temperature exceeds a predetermined temperature, the system analyses the temperature in each of the distribution ports to determine which of the corresponding zones are above the predetermined temperature. By positioning the temperature sensors in the distribution ports the information can be directly transmitted to the control circuitry and software within the PCB, 607. In the event that PCB 607 receives a signal indicating that the return temperature in the shared pod is above the predetermined temperature, PCB 607 can then determine which of the distribution pods has a water temperature above the predetermined temperature and activate the control circuitry to close the relevant distribution ports. This will be explained in further detail in Figure 7.

Figure7 The central heating system and control device as described herein is configured to enabie the temperature of a flow of water through a central heating system to be monitored effectively such that water which is above a predetermined temperature can be prevented from flowing to a boiler. This would prevent the situation where, for example, a condensing boiler suffered from a water temperature which was too high to enable it to condense effectively.

Thus, the operation of the control system for the control device described herein previously is shown in the flow chart in Figure 7.

At step 701, a question is asked to determine if the common return temperature to the boiler is above a predetermined temperature. In an embodiment, this may be monitored directly within the control device by means of the shared port. However, in an alternative embodiment this may be recorded from another position in the return flow elsewhere in the system. The predetermined temperature is set as any suitable temperature which the user requires the system to operate at, an example being a temperature of around 55°C for a condensing boiler. It is appreciated that other condensing boilers may operate at significantly different temperatures to 55°C, however, such a system is appreciated to work under the same principles as described herein.

If the question at step 701 is answered in the negative, the control device remains open and allows the water flow to return to the boiler.

Alternatively, if the question is answered in the positive (i.e. that the return temperature is above the predetermined temperature and is too hot for the boiler to process at its optimum efficiency) then steps are performed to ascertain which of the distribution ports require closing to prevent water which is above the predetermined temperature from entering the boiler.

At step 702, the temperature is measured and monitored in all of the zones of the heating system by monitoring the flow into each of the distribution ports described previously. At step 703 the temperatures in each of the zones is compared to the predetermined temperature in order to identify which zones are above the predetermined temperature. The zones which are above this predetermined temperature (hot' zones) are thus flagged and, at step 704, the distribution ports corresponding to a particular zone which has registered as over the predetermined temperature are then closed. The system is configured to close the zones in which the temperature is above the predetermined temperature for a set period of time to enable the water temperature to cool down. When this happens, the water is held in the radiators of these zones such that the control device is closed to prevent water flow when the predetermined temperature is exceeded in that particular zona Thus, in the case of a condensing boiler, the step maintains the return temperature to the boiler below the predetermined temperature to allow the condensing boiler to condense. For a user in the rooms in each of the zones the temperature drop will remain unnoticed as the radiators in the zones will still feel hot to the touch as they will still emit a substantial proportion of heat as the zones will be at or near their required temperature.

After the set period has passed, the hot' zones are reopened and the question at step 701 is asked again. Thus, the hot' zones will continue to remain closed if they exceed the predetermined temperature until the common return temperature to the boiler is below the predetermined temperature. Thus, when the question at 701 is answered in the negative, the common return temperature has been measured as below the predetermined temperature and a return flow of water is allowed to the boiler, as shown at step 705.

The system, therefore, only allows a flow of heated water which is below the predetermined temperature to return to the boiler such that the boiler can operate at the most efficient setting possible.

It is appreciated that the principle of the invention disclosed herein can be achieved by alternative methods and can be achieved both mechanically (such as by the thermostatic device shown in Figures 2 and 3) or as part of an electrical control system (such as the system described with reference to Figures 6A and 6B).

Claims

Claims 1. Apparatus for controlling the flow of water in a central heating system comprising: at least one radiator; and a device for restricting the flow of water through said central heating system; wherein said device retains the flow of water in said at least one radiator when the temperature of said flow of water through said radiator is above a predetermined temperature.
2. Apparatus for controlling the flow of water in a central heating system in accordance with claim 1, wherein said central heating system is a zoned heating system comprising a plurality of zones.
3. Apparatus for controlling the flow of water in a central heating system in accordance with claim 2, wherein said device comprises: a plurality of distribution ports, each distribution port corresponding to one of said plurality of zones; and a shared port, whereby the flow of water is configured to flow between said plurality of distribution ports and said shared port.
4. Apparatus for controlling the flow of water in a central heating system in accordance with claim 3, wherein flow through each of said plurality of distribution ports is restricted by said device such that flow can be prevented to any number of said plurality of zones.5. Apparatus for controlling the flow of water in a central heating system in accordance with claim 4, wherein said central heating system is further configured to restrict flow through each of said plurality of distribution ports by means of a cam configured such that flow to all of said plurality of zones can be prevented.
5. Apparatus for controlling the flow of water in a central heating system in accordance with claim 4, wherein said central heating system is further configured to restrict flow through each of said plurality of distribution ports by means of a cam configured such that flow to all of said plurality of zones can be permitted.
6. Apparatus for controlling the flow of water in a central heating system in accordance with claim 1, wherein said central heating system further comprises at least one temperature sensing device for monitoring the temperature of the water flow
7. Apparatus for controlling the flow of water in a central heating system in accordance with claim 6, wherein said temperature sensing device includes a temperature sensitive wax capsule responsive to said predetermined temperature.
8. Apparatus for controlling the flow of water in a central heating system in accordance with claim 6, wherein said temperature sensing device is an electrical temperature sensor.
9. Apparatus for controlling the flow of water in a central heating system in accordance with claim 1, wherein said central heating system further comprises a boiler.
10. Apparatus for controlling the flow of water in a central heating system in accordance with claim 9, wherein said boiler is a condensing boiler.
11. A method of controlling the flow of water in a central heating system comprising at least one radiator and comprising the steps of: fitting a device for restricting the flow of water in said central heating system; and io retaining the flow of water in said at least one radiator when the temperature of said flow of water through said radiator is above a predetermined temperature.
12. A method of controlling the flow of water in a central heating system in accordance with claim 11, further comprising the steps of: monitoring the return temperature to a boiler by a temperature sensing device; and closing said device, to prevent water flow when said predetermined temperature is exceeded.
13. A method of controlling the flow of water in a central heating system in accordance with claim 12, wherein said boiler is a condensing boiler and said steps maintain said return temperature below said predetermined temperature to allow said condensing boiler to condense.
14. Apparatus for controlling the flow of water in a central heating system as described herein with reference to the accompanying Figures.
15. A method of controlling the flow of water in a central heating system as described herein with reference to the accompanying Figures.