GB2474454A

GB2474454A - Fuel consumption controller

Info

Publication number: GB2474454A
Application number: GB0917975A
Authority: GB
Inventors: James Mcalorum; Trevor Gordon; Gerard James Shaw
Original assignee: ECOCE ENGINEERING Ltd
Current assignee: ECOCE ENGINEERING Ltd
Priority date: 2009-10-14
Filing date: 2009-10-14
Publication date: 2011-04-20
Also published as: WO2011045776A1; IES20100663A2; GB0917975D0; IE20100662A1

Abstract

A fuel consumption controller, especially for an oil or gas fired domestic heating burner, wherein the amount of fuel burnt in a time period is estimated using the time the burner has been firing and the flow rate specification of a fuel nozzle 9 which delivers fuel to the burner 3, the operation of the burner is limited for the remainder of the time period if the estimated fuel consumption exceeds a volume limit. Preferably the burner is operated by a control waveform, such as a series of pulses each of which represents a fixed volume of fuel, and therefore the duration of the pulses depends on the flow rate specification of the fuel nozzle. The comparison between the estimated fuel use and the volume limit may be worked by counting down the number of pulses allowed within the time period.

Description

"A Fuel Consumption Controller"

Introduction

This invention relates to a fuel consumption controller for a heating installation burner.

The majority of households and premises equipped with a heating installation operate using either an oil-fired burner, or a gas-fired burner. The cost of operating the oil-fired or gas-fired burner can be highly unpredictable. This is due to the fact that the operation of the burner is dependent on weather and climatic conditions and individual preferences relating to desired temperature in the household or premises. Furthermore, the heating installations are often left on as a result of human error for sustained periods of time when it is unnecessary to do so. In addition to the above, the condition of the burner equipment can have a significant bearing on the efficiency of the burner which in turn has a bearing on the amount of oil or gas used by the heating installation to heat the house or premises. This leads to an unpredictable cost of running the heating installation.

Another problem with the known heating installations is that due to the unpredictable rate of consumption of the burner, it is quite common for the heating installation to run out of fuel. Research has shown that approximately nine out of ten people have experienced unexpectedly running out of fuel to heat their household at some stage. Various devices have been proposed to monitor the amount of fuel remaining in an oil tank and to alert the household owner when the amount of fuel falls below a predetermined limit, thereby reminding the household owner to order more fuel. However, these known controllers do not allow the home owner to control or preset the rate of consumption of the fuel.

It is an object of the present invention to provide a fuel consumption controller for a heating installation burner that enables the owner of the household or premises to carefully control fuel consumption by the burner and provide a more predictable operating cost of the burner.

Statements of Invention

In accordance with the invention there is provided a fuel consumption controller for a heating installation burner comprising: means to set a fuel consumption volume limit for a time period; means to monitor when the burner is firing in that time period; means to estimate the amount of fuel that has been burnt in that time period using the amount of time that the burner has been firing in that time period and a flow rate specification of a fuel nozzle through which the fuel is delivered into the burner; means to compare the estimated amount of fuel that has been burnt in that time period with the fuel consumption limit for the time period; and means to limit the operation of the burner for the remainder of the time period, on the amount of fuel estimated to have been burnt in the time period reaching the fuel consumption limit for that time period.

In one embodiment of the invention there is provided a controller in which the controller comprises means to receive the flow rate specification of the fuel nozzle.

In another embodiment of the invention there is provided a controller in which the controller has a male plug and a female socket.

In a further embodiment of the invention there is provided a controller in which the controller has a flow rate table with a flow rate for the time period for the flow rate

specification.

In one embodiment of the invention there is provided a controller in which the means to limit operation of the burner comprises means to generate a control waveform for the burner. The control waveform is a continuous signal that turns off to interrupt the burner. Ideally, the waveform is a square waveform. Effectively therefore, the control waveform operates the on/off control of the burner when the estimated fuel consumption limit has been reached for that time period.

In one embodiment of the invention there is provided a controller in which the control waveform comprises a plurality of pulses.

In one embodiment of the invention there is provided a controller in which each pulse represents a fixed volume of fuel to be delivered to the burner.

In one embodiment of the invention there is provided a controller in which the number of fix width pulses is determined by the flow rate specification of the fuel nozzle.

In one embodiment of the invention there is provided a controller in which the means to compare the estimated amount of fuel that has been burnt in that time period with the fuel consumption limit for the time period comprises a pulse count-down counter.

In a further embodiment of the invention there is provided a method of controlling a heating installation burner comprising the steps of: setting a fuel consumption rate limit for a time period for the burner; monitoring the fuel consumption of the burner in that time period; comparing the monitored fuel consumption of the burner with the fuel consumption rate limit; and limiting the fuel consumption of the burner on the amount of fuel calculated to have been burnt in that time period reaching the fuel consumption limit for that time period.

In one embodiment of the invention there is provided a method in which the step of monitoring the fuel consumption of the burner comprises: monitoring when the burner is firing in the time period; and estimating the fuel consumption using the duration of time for which the burner has been firing in that time period and a flow rate specification of a fuel nozzle through which the fuel is delivered into the burner.

In another embodiment of the invention there is provided a method in which the method comprises the initial step of: setting a flow rate specification of the fuel nozzle.

In a further embodiment of the invention there is provided a method in which the step of limiting the fuel consumption of the burner comprises the steps of: generating a control waveform for the burner.

In one embodiment of the invention there is provided a controller in which the step of generating a control waveform for the burner comprises generating a plurality of pulses.

In one embodiment of the invention there is provided a controller in which the step of generating a pulse comprises generating a number of pulses dependant on the

flow rate specification of the fuel nozzle.

In one embodiment of the invention there is provided a controller in which the step of generating a plurality of pulses comprises generating a plurality of pulses each of which is representative of a fixed volume of fuel to be delivered to the burner.

In one embodiment of the invention there is provided a controller in which the step of comparing the monitored fuel consumption of the burner with the fuel consumption rate limit comprises the steps of: setting a pulse count-down counter with an integral number equal to the number of pulses corresponding to the fuel consumption rate limit; on each pulse, decrementing the pulse count-down counter by one until the pulse count-down counter reaches zero.

In one embodiment of the invention there is provided a heating installation comprising a burner, a water heating system heated by the burner and a controller limiting the amount of fuel burnt by the burner in a time period based on a estimation of the fuel burnt in a given time period, estimated using the amount of time that the burner has been firing in that time period and a flow rate specification of a fuel nozzle through which the fuel is delivered into the burner.

Detailed Description of the Invention

The invention will now be more clearly understood by the following description of an embodiment thereof, given by way of example only in which: Figure 1 is a diagrammatic representation of a heating installation according to the present invention; Figure 2 is a diagrammatic representation of a fuel consumption controller in accordance with the invention; Figure 3 is a diagrammatic representation of the implementation of the fuel consumption controller in a heating installation; Figure 4 is a table showing how dipswitches may be used to set the fuel limit; Figure 5 is a table showing how dipswitches may be used to generate the control pulse from the controller; Figure 6 is a table showing the oil/fuel rate in US Gallons per hour for different nozzle sizes; and Figures 7(a) and 7(b) are pulse trains for two different nozzle sizes and two different fuel consumption rates.

Referring to Figure 1 there is shown a heating installation, indicated generally by the reference numeral 1, comprising a heating installation burner 3 which receives a control signal 5 from a controller (not shown) and a fuel feed 7 from a fuel tank (not shown). The burner 3 has a nozzle 9 which is a calibrated device that delivers a fixed quantity of fuel per hour dependent on the size and design of the nozzle. The heating installation further comprises a boiler 11 containing a fluid, in this case water that is heated by the burner 3 and a pump 13 that pumps the heated water through a heating system (not shown).

In use, fuel is delivered from the fuel tank through the fuel feed line 7 and out through nozzle 9 where it is combusted using a burner flame. The combusted fuel is used to heat the fluid in the boiler 11. The heated water in the boiler 11 is then circulated through the heating system to heat the house or premises.

Referring to Figure 2, there is shown a diagrammatic representation of a fuel consumption controller for a heating installation burner indicated by the reference numeral 21. The fuel consumption controller 21 comprises a casing 23 having a female socket connection 25, a male socket connection (not shown) and various control switches 26, 27, 28, 29. Control switch 29 is a fuel consumption limit set switch which may be operated to allow a user to determine the amount of fuel that is to be burnt by the burner in a given time period, usually an hour time period. The control switch 28 is a nozzle flow rate specific switch which allows the flow rate of a particular nozzle to be input into the controller. Control switch 27 comprises an override switch and control switch 26 comprises a calibrate switch.

Referring to Figure 3 there is shown a diagrammatic representation of the controller implemented in a heating installation indicated generally by the reference numeral 31, the controller 35 is located between a thermostat 33 and a safety thermostat 37 which supply the control signal to the burner 3 via a fuse 39.

In use, an owner of the heating installation sets the nozzle flow rate specification switch 28 to correspond to the flow rate specification of the nozzle 9 in the burner 3.

They then set the amount of fuel that they wish to burn by adjusting the fuel consumption limit switch 29. The user presses the calibrate switch and the unit begins to monitor the fuel consumed by an internal counter which counts control pulses sent to the burner. Each pulse represents 10cc of fuel being delivered to the burner. A clock is provided that counts out a desired time period, for example an hour, in which the amount of fuel being consumed is monitored. Therefore, by knowing the amount of pulses in a particular time period, it is possible to determine the amount of fuel that has been consumed in that time period. The controller estimates the fuel consumption based on the time that the burner is operating and the flow rate specification of the fuel nozzle.

An algorithm extrapolates the volume of fuel consumed and when the volume exceeds the desired limit the unit will inhibit the burner until the next time period begins. Once the time period has elapsed, the unit will allow the burner to operate again provided that the burner is called to operate. It is envisaged that it is preferable to set the time period as an hourly time period as in this way, the heating system will not have sufficient time to cool down thereby conserving fuel required to bring the system back up to temperature. The override switch 27 allows the user to override the unit and run the burner in the normal mode without any restriction of fuel which may be desired in certain circumstances. If the override switch has been used, the unit has to be recalibrated before calculation can begin again.

It can be seen from the above that the user can set the duration of time that they wish the fuel to last. For example, they may say that they wish 1000 litres of fuel to last 1000 operating hours of the burner, in which case they can limit the amount of fuel to one litre per hour. The controller will thereafter prevent more than one litre of fuel being consumed in any hour of operation of the heating installation burner.

Referring to Figures 4 to 6 inclusive, there are shown various tables used by the controller to operate the heating installation. Referring specifically to Figure 4 there is shown a table for dipswitches that set the fuel limit setting. In the table 41, a number of fuel limit settings in increments of 100cc (lOOmL) from 100 cc to 1000 cc (1L) is provided and depending on the position of the four dipswitches (not shown), the fuel limit setting is provided. Other switches instead of dipswitches could be used however the dipswitches offer a relatively inexpensive option. As an alternative to the dipswitches a multi-position rotating knob, a larger set of switches each with an individual setting or a digital keypad could be used. Indeed, other types of switches could be used if desired.

Referring specifically to Figure 5 of the drawings, there is shown a table indicated generally by the reference numeral 51 which shows a fuel pulse generator responsive to the dipswitch settings. Depending on the dipswitch settings, the fuel pulse generator will generate a control pulse to limit operation of the boiler to the fuel limit setting chosen in previous steps.

Referring to Figure 6, there is shown an oil fuel rate in litres per hour for various different nozzle sizes, indicated generally by the reference numeral 61. For example, it can be shown that for a nozzle size of 0.40 USgal/Hr (the nozzle size is rated in USgal/Hr, United States gallons per hour), using the standard pressure for a heating system, 100 psi pressure (6.895 bar), the fuel burn rate would be 1.51 litres per hour.

Therefore, if the user stipulates that only 0.5 litres is to be burned in any given hour, it will be understood that the heating installation burner will be operated for no more than 19 minutes 52 seconds every hour ((0.5 ÷ 1.51) = 0.3311 *Hour) Referring to Figures 7(a) and 7(b), there is shown a pair of pulse trains 71, 73 respectively, for different nozzle sizes and different quantities of fuel to be consumed.

Each pulse represents a volume of 10cc of fuel. Every time there is a pulse, a pulse count-down counter is decremented by one. When the pulse count-down counter reaches zero, no more pulses will be allowed for that time period. For example, the fuel burn rate may be set to 1 litre per hour and this will equate to 100 pulses (100 x 10cc = 1 litre). Therefore, the pulse count-down counter will be set to 100. Each time there is a pulse, the counter is decremented by one and after 100 pulses the counter will reach 0. Once it reaches 0, the burner will be inhibited to run for the remainder of the chosen time period, for example for the remainder of that hour. Once the remainder of the hour has elapsed, the clock will be reset and the pulse count-down counter will be reset so that the fuel can again be delivered to the burner for the next time period until the amount of fuel allotted for that time period has been consumed.

In Figure 7(a), in order to generate the pulse train 71, the nozzle size is 0.40 USgal/Hr and the pulse is set at setting one (Figure 4). In this way, the fuel limit setting is set at 100cc of fuel in one hour. Each pulse has a duration of 23.84 seconds in order to dispense 10cc of fuel. There will be 10 pulses allowed per hour to reach the 100cc limit. Once the ten pulses have been carried out, no further pulses will be allowed until the next time period.

Therefore, if the burner is operated continuously, there will be 100 pulses after 2384 seconds, just under forty minutes, and if the burner has been operated continuously, the burner will have burnt 1 litre of fuel in that time and the burner will be inhibited for the remainder of the time period, for example the remainder of the hour. It will be understood that the burner may not operate continuously due to the fact that the user, a thermostat device or other device may cut off the burner during the time period when it is not required and therefore the controller only monitors the length of time that the burner is in operation. In the present example, for each 23.84 seconds that the burner is in operation, a pulse is generated and the pulse counter is decremented by one.

In Figure 7(b), in order to generate the pulse train 73, the nozzle size is 1.20 USgal/Hr and the setting is set at setting ten (Figure 4). In other words, the amount of fuel to be consumed in an hour will be 1000cc of fuel. Each pulse will have a duration of 7.93 seconds and again each pulse will dispense 10cc of fuel. In this way, the duration of time between the metering pulses is dependant on the nozzle size and the number of the pulses in a given period will be dependent to an extent on the size of the nozzle.

The number of pulses is monitored to determine the amount of fuel consumed.

In other words, every time that the burner has burnt 10cc of fuel, a pulse is generated.

A nozzle size of 1.20 USgal/Hr will dispense 10cc of fuel in 7.93 seconds thereby causing a pulse to be generated every 7.93 seconds during continuous operation of the burner. Similarly, a nozzle size of 0.40 USgal/Hr will dispense 10cc of fuel in 23.84 seconds thereby causing a pulse to be generated every 23.84 seconds during continuous operation of the burner. Once the desired limit of fuel has been burnt in a given time period, a signal is sent to shut off the burner for the remainder of the time period.

Preferably the unit will be lightweight and relatively diminutive in structure having a height of approximately 50 mm, a depth of approximately 75 mm and a length of approximately 150 mm. Furthermore, the device will be provided with a female socket and a male socket so that it may be inserted directly in line with the thermostats in existing systems so that it can be retro-fitted into existing systems. Alternatively, suitable wiring may be provided so that it may be wired up to a system. In the embodiment shown, various switches are provided and it will be understood that these could be provided by way of a keypad or other type of user interface and indeed there may be a graphical user interface such as an LCD screen, a touch screen or other like screen that can display current settings to the user and allow the user to programme the device using the LCD and/or the keypad which may be an alphanumeric keypad, an alphabetic keypad, a pictogram keypad or simply a numeric keypad.

Furthermore, in the embodiment shown, the user is able to set the nozzle size.

However, it will be understand that the nozzle size may be fixed for a particular type of controller and in certain embodiments the nozzle size may not be set by the user. In this way different controllers will be provided for the different nozzle sizes to take this responsibility away from the user. The device can be mains operated, or alternatively a battery supply could be provided.

It will be understood that by incorporating a fuel consumption controller such as that described, the owner of a household or premises can set the number of burn hours that they wish their tank of fuel to last and therefore this gives them some control over the usage and cost of operating the heating installation. This will reduce the likelihood of the user running out of fuel inadvertently and will also allow them to operate their heating installation in a more effective and efficient manner.

It is envisaged that the method and the controller could be applied to a wide range of disparate areas of endeavour where it is desirable to monitor the amount of fluid that is being dispensed through the nozzle in a given time period. Put simply, the method could be applied to any area where a pulse is generated based on the nozzle size and the amount of time that the nozzle has been dispensing fluid through the nozzle. The number of pulses is monitored and when the desired number of pulses has been reached, indicative of a fluid limit being reached, the flow of fluid is restricted.

In the specification the terms "comprise, comprises, comprised and comprising" or any variation thereof and the terms "include, includes, included and including" are deemed to be totally interchangeable and they should be given the widest possible interpretation.

The invention is in no way limited to the embodiment hereinbefore described which may be varied in both construction and detail with the scope of the claims. -12-