GB2478181A

GB2478181A - Electronic controller for use with a heat supply unit

Info

Publication number: GB2478181A
Application number: GB1102664A
Authority: GB
Inventors: Patrick Broderick
Original assignee: Individual
Current assignee: Individual
Priority date: 2010-02-25
Filing date: 2011-02-16
Publication date: 2011-08-31
Anticipated expiration: 2031-02-16
Also published as: EP2539640A2; GB201014595D0; GB2478181B; GB201102664D0; WO2011104505A2; WO2011104505A3

Abstract

The controller 4 is suitable for use with a heat supply 2 unit supplying heat to a heating system. The controller includes a control circuit adapted to provide a sequence of control signals to periodically turn the heat supply unit on and off during successive operational periods of the controller. Each operational period is started and ended by respective activation and deactivation signals provided to the controller from an external device 8, 10. During an operational period, at least one period of time for which the heat supply unit is turned on is of differing duration to at least one other period of time for which the heat supply unit is turned on. The heat supply unit may be a boiler. The external device may be a timer 8 or thermostat 10. The initial period of time for which the heat supply unit is turned on may be longer than any subsequent period of time for which the supply unit is turned on. The controller provides a more energy efficient boiler. A method of controlling a heat supply unit suitable for supplying heat to a heating system is also claimed.

Description

TITLE

Controllers for heat supply units

DESCRIPTI ON

Technical Field

f he present imention ielates to contiollers for heat supply umts (e g gas or oil-fired boilers) that form part of a heating system.

Summary oftbe invention

Ihe present invention prosides a controller for a heat supply unit (c g a boiler) foi supplying heat to a heating vs stem, the c ontioller including a control circuit that is adapted to ptovide a sequence of control signals to penodically turn the hcat supply unit ON and OFF during succcssn e operational penods of the ontroller, each operational period being started by an activation signal provided to the controller from an external device and being ended by a deactivation signal provided to the controller from an external device, wherein at least one period of time for which the heat supply unit is turned ON is longer than at least one other period of tune for which the heat supply unit is turned Ots during a particulai operational period The eontrol]ei may be connected to an existing central healing (or primary) controller or integrated with the main boiler coIltroller.. for example. The control circuit n'iplerncnts a softs ate control progiam that provides savings in fuel consumption and reduces CQ emissions There are three heating phases in a typical heating cycle Phase I is when the heat suppl unit (e g boiler) runs full bote to heat the water in the heating system to its desired (01 target') temperature Phasc 2 is afiei the tai get temperature of the water has beth reached, but the heat supply unit remains activated until a desued (or target I building rooni temperature is rcached and the heat supph unit is deactivated by a thermostat, Phase 3 is after the thermostat has been engaged and peHodieally activates and deactivates the heat supply unit to maintain the huilding'room at its target temperature The control program particularly saves fuel during phase I and phase 2 of the heating cycle In a typical an'angement the sequence ot cont ol signals will turn the heat suppl\ unit ON for a longer period of time at the start of each operational period. After this initial longer period of time the heat supply unit may be turned ON for shorter periods of time or turned ON for one or more longer periods of time before being turned ON for shorter periods of time.

The contiollei ieeenes actn afton signals and deactivation signals fron extcrnal de\ices, optionally from the same external device An aetis anon signal may be pios med b a conventional timer to turn the heat supply unit ON at a particulir time or by a thernio stat to turn the heat supply unit ON when a measured temperature (e g a buildingiroom temperature) falls below a sdpoint temperature Similarly, the deactivation signal may be provided by a eorwentional timer to turn the heat supply unit OFF at a particular time or by a thermostat to turn the heat supply unlt OFF when a measared temperature rises above a setpoint temperature Actis ation and deactivation signals may also be provided in response to unscheduled heating demands made bs the user These activation and deacnv4tloii signals would typically be used to turn tnt heat supply unit ON and OFF but during these cycles the actis ation periods an.. interrunted by the controllci ot the present invention which provides its own sequence of eontiol signals to control the ON OFF op.ation of the heat supply unit Each succe\sive opeiational period of the controller will be started by an activation signal and ended by a deactivation signal.

The heat supply unit is preferably controlled in the same way during each opeiational period Hos ever, ditlerent control progi ains (c g timings) can be applied during different operational periods.

At the start of each operational period the heat supply unit is preferably turned ON for an initial penoo ot time ihis raises the temperature of the water in the heating ss stein -and hence i asses the tempei atm e ot the parts ot the heating system that are used to actually provide space heating (e.g. radiators) to a desired (or target' temperature. Once the initial period of time has elapsed, the control circuit ivill periodically turn the heat supply unit OFF and ON: antil the end of the particular operational period. In other words, during each operational period there will normally be periods or time ihen the heat supply unit will not he supplying heat to tile heating S system e en though heat is being demanded by the external devu.c(1⁄4) The periods of time during which the heat supply unit is turned OFF by the control en cuit are not long inough for the temnerature of the radiators to reduce sign'ficantly and the heating system \%ilI continue to pioiide space heating cen when the heat supply unit is not sunplying heat A small tall in the radiator temperature (e g one oi two °C) is expected when the heating supply unit is turned OFF but this does not have a significant affect on the space heating This means that the timings ate typically pre-programni ed to achieve the target temperature of the heating system lie, the controller is temperature dependent) e en though the heat supply unit is turned ON and OFF in response to contiol signals that are based entuely on an internal timer and are derived independently of temperature Penodically turning the heat supply unit OFF and oN during each operational period results in energy savings without compromising heat output.

In a typical control program, at the stait of each operational period the heat supply unit will he turned ON foi an initial period of 15 minutes to raise the temperature of the heating system to its normal operating temperature The heat supply unit will then be turned OF1 for 5 mrnutcs ON for 10 minutes OFF toi 5 minutes ON for 10 minutes etc. until a deactivation signal is received and the particular operational period ends In another control program, at the start of each operational period the heat supply unit will be turned ON for an initial period of 15 minutes to. raise the temperature of the heating system to its normal operating teinpciature The heat supply unit will then be turned OFF for 5 minutes, ON for a further period of 15 minutes to further raise the tempeiature of the Fearing system, OFF for S minutes ON for 10 minutes, OFF for S -4...

minutes, ON for 10 minutes etc. until a deactivation signal is received and the particular operational period ends The vauous timing1⁄4 will normally be pie-programmed but in sonic circumstances a a user may be able to select from different pre-programmed options.

As soon as a demand for heat is rceei ed by the controller (i. e an acti ation signal is received) then the heat supply unit is turned ON to start and raise the heating system to the desired (or target') tèrnperatnre to maintain user comfort.

I he present in entron further provides a mt1thod of ontrothng a heat supply unit for supplying heat to a heating system dunng successive opuational periods of a controller, each operational period being startud by an acirs ation signal prns ided to the controller from an external device and being ended by a deactivation signal provided to the controller from an external de ice the method comprising the steps of pros iding a sea uen. e of control signals to periodicalry turn the heat supply unit ON and OFF, wherein at least one period of time fur which the heat supply unit is turned ON is longer than at least one other period of time for which the heat supply unit is turned ON during a particular operational period.

The present inventiou further provides a time-based controller that optimises the extradion of latent heat from a heating system, after a heat supply unit is turned OFF nhilst keeping the temperature of the heating system to ithin about 10% of a target temperature Drawinn Figure 1 is a schematic drawing showing a heating system incorporating an electronic controller according to the present invention Figure 2A shows a first example of a control program fur controlling the operation of the heating system; and Figure 2B shos a second example of a control program for controlling the opeiation of the heating system.

With reference to Figure 1, a domestic heating system includes a gas boiler 2 that supplies hot s ater to tadiators (not shon a) An electronic controllu 4 includcs a control circuit that provides ON and OFF signals to the boiler controller 6 that is integrated with the boiler 2 and controls the direct operation of the gas burners etc. Although in Figure 1 the elcctronic controller is shown as a sqarate or stand-alone component, in practice it can he physically integratcd with the boiler controller 6 When thc electronic conti oller 4 sends an ON signal the boner contrnllci 6 turns to boiler ON so that it starts supplying hot v. ater to the radiatois (not shown) for space heating and when the electronic controller sends an OFF Signal the boiler controller turns the boiler OFF.

The electronic controller 4 receives activation (ACT) signals and deactivation (DFACT) signals flom one oi more external des ices Figure 1 shows tsco typical external devices, namely a timer 8 which provides activation and deactivation signals at certain user-defined times of the day and a thermostat 10 which provides activation and deactivation signals depending on whether a measured temperature is above or below user-defined setpninttemperatures. Other external devices clan he used.

As shossn in Figures 2A and 2B each optiational penod of the electronic controller 4 is started by an activation (AC. 1) signal and ended by a deactivation (DEACT) signal Ne attn ation and deactivation signals can be provided h any of the external devices Each operational period essentially represents a period of time (T0) hen space heating is demanded Within each operationil penod the electronic contioller 4 opeiates a pre-progiammed contiol piogram which sends a sequence of ON and OFF signals to the boiler controller 6 so that the boiler 2 is turned ON arid OFF The electronic controller 4 is optionally pros idcd ith sescral pre-programmed control programs which can be selected by a user.

Ac soon as the electronic controller 4 ieceivs an attn aflon (AC IF) signal from an external device the electronic controller sends:an ON: signal to the boiler controller 6 so that the boiler 2 is turned ON and starts to provide hot water to the radiators (not shown) fhr space heating. The boiler 2 is turned ON for an initial period of time (Ti) and is then subsequently penodically turned OFF and ON by the hoilei controller 6 under the control of the electronic controller 4 as shown in Figure 2. The initial S period of tune (TI) is longer than the othei penod of time (T0) hen thc boiler 2 is turned ON.o that the iadiatois (not sho\kn) are raised to the desued (oi targeV) tempeiatuic to maintain user comfort at the start of each upeiational period The boiler 2 continues to be periodically turned OFF and ON by the boiler controller 6 under the control of the electronic controller 4 until the electronic controller receives a deactis anon (OF ACT) signal from an external device In the typical example shown in Figure 2A the first activation (AC T) signal is recencd from the tunet S it a start tune (e g 7 OOam) The first operational penod will continue until the first deactivation (DEA2T) signal is received from the thermostat 10 when a measured temperature rises above a setpoint temperature. The second operational period will start when the second activation (ACT) signal is rece ed from the thermostat 10 when a measured temperature faIls below a setpomt temperature and continues until the second deaetn ation (OF ACT) signal is received from the thermostat when a measured temperature uses aboi e a setpoint temperature rhe thud oprational penod will start when the thud activation (ACT) signal is received from the thermostat 10 when a measured temperature fails below a setpoint temperatw c and ontmnucs until the third deaetn ation (DEACT) signal is received from the timei 8 at an end tune c g 9 3Oarn) The conhol progiarn tunings fom each operational period are the same: T1 15 minutes T0ft 5 minutes minutes But it will he readily appreciated that nther timings may be used depending on the heating system and its operational requirements. For example, the first time the boiler 2 is turned ON again after the initial period then it may be turned on for a longer penod of time (1) and then each suhsquent time the boiler is turned ON it ma he turned on for a shorter period of time (T). Such an alternative control program shown in Figure 2B would provide two longer periods of time at the start ef each operational period to help raise the temperature of the heating system to its target temperature.

Claims

-CLAIMS1. A controller for a heat supply unit for supplying heat to a heating system, the controller including a control circuit that is adaptcd to pro' ide a st quence of control signals to pen odically turn the heat supp1\ unit ON and 01 F during successis e operational pe1iods of the controller each operational penod being started by an activation signal provided to the controller from an external device and being ended in a deaths ation signal providcd to the controller from an external des icc wherein at least one penod of time for i hich the heat supply unit is turned ON is longer than at least one other penod of time for which the heat supply unit is turned ON during a particular operational period..
2. A controller according to claim 1, wherein the control circuit is adapted to provide a controlS signal to turn the heat supply unit ON for an initial period of time at the start of each operational period, the initial period of time 1or vhtch the heat supply unit is turncd (Is being longei than at least one other penod of time for which the heat supply unit is turned ON during a particular operational period.
3. A method of controlling a heat supply unit for supplying heat to a heating system dunng succcssii e operational periods of a controller, each operational penod being started bs an activation signal pros ided to the controller from an external desne and being ended by a deacus anon signal piouded to the controller from an external des ice, the method comprising the steps of prouding a sequence of control signals to penodreally turn the heat supply unit ON and OFF stherein at least one period of time foi which the heat supply unit is turned ON is longer than at least onc other period of time for which the heat supply unit is turned ON during a particular operational period.
4. A niethod of controlling a heat supply unit according to claim 3, thrther comprising the step of providing a control signal to turn tire heat supply unit ON for an initial period of time at the start of each operational period, the initi& period of time for n hid' the heat supply unit is turned ON being longei than at least one other period of time for which the heat supply unit is turned ON! during a particular operational period.