GB2174510A

GB2174510A - Heating system controller

Info

Publication number: GB2174510A
Application number: GB08508743A
Authority: GB
Inventors: Paul Telco
Original assignee: Individual
Current assignee: Individual
Priority date: 1985-04-03
Filing date: 1985-04-03
Publication date: 1986-11-05
Also published as: GB8508743D0; GB2174510B

Abstract

This invention relates to a heating system controller for connecting to control any one of a plurality of heating systems. The controller comprises a logic array 6 having outputs connected to drivers 7 for operating various elements of a heating system 1. Elements 3 to 5 of the heating system produce time varying output responses which are fed directly into the logic array 6. Temperature sensors 2 of the system are fed through a processing unit 8 prior to being relayed to the logic array 6. The logic array 6 includes an EPROM having a look-up table containing a number of directing instructions for actuating the drivers 7 to operate the various elements of the system 1. Different pages of instructions are examined depending upon the input valves fed from elements 3 to 5 and 8. After accessing the appropriate page of system directing instructions, the controller initiates the driver 7 to operate the appropriate elements 1 of the heating system. <IMAGE>

Description

SPECIFICATION Heating system controller This invention relates to heating system controllers.

Heating systems are employed in for example domestic and commercial properties such as hotels and factories. With the advent of higher fuel costs users of the systems have sought methods of reducing the running costs. Initially, such controls for heating systems were a simple mechanical thermostat and a clock fairing a rotatable cam for actuating adjustable contacts to determine heating periods and levels. Such forms of control were relatively crude and particularly for larger heating systems a more sophisticated control was desirable in order to effect greater efficiency in fuel usage.

Thus, newly installed heating systems now incorporate sophisticated controllers which can achieve savings of typically up to 45% in fuel costs compared with the above type of controls. Each newly installed heating system incorporates a controller specifically designed for the type of heating system. By incorporating an advanced type of controller using energy regulation theory the aforementioned fuel cost savings can be attained.

However, each type of newly installed heating system requires a respective controller designed specifically for that type of system. Thus, a number of different controllers must be manufactured and the particular type of controller matched to the particular type of heating system. Furthermore, the controllers currently available are mainly designed to be installed simultaneously with the heating systems i.e. as a composite specification. This completely ignores already installed heating systems and if the aforementioned fuel savings are to be effected then not only must the controller be matched with the type of heating system already installed but the heating system installed must frequently be re-configured in order to suit the controller.Consequently, it can be seen that heating system controllers available are inflexible and make it difficult to apply the advanced heating system control techniques to heating systems already installed.

It is an object of the invention to provide a heating system controller of an advanced type which is fittable to a variety of heating systems.

According to the invention there is provided a heating system controller for connecting to control any one of a plurality of heating systems and comprising : store means storing a look-up table of system directing instructions for said plurality of heating systems; control means connected in use to receive both time varying and temperature sensitive input signals to indicate for said one heating system the user and system heat demand together with the cause thereof and the control means in response thereto accessing said store means to retrieve system directing instructions dependant on said input signals; and output means connected to the control means to receive the retrieved system directing instructions to produce output signals for directing operation of elements of said one heating system; wherein the control means includes access variation means manually adjustable to define said one heating system, whereby the access variation means restricts the control means access to said look-up table to system directing instructions relating only to that one heating system.

In this way, the heating system controller of the invention can be connected to already installed elements producing time varying and temperature sensitive input signals and can be connected to apparatus for operating elements of the heating system regardless of the particular heating system since the system directing instructions therefor are already stored in the store means and a user, by manually adjusting the access variation means, can limit the control means to access the system directing instructions relating only to that particular heating system. It can therefore be seen that the heating system controller of the invention is very flexible and can be used with a number of different heating systems and requires only simple alteration of the access variation means.Therefore, the controller of the invention can be applied to both already installed heating systems and brand new systems. Thus, an advanced type of controller using energy regulation theory can be simply connected to already installed heating systems.

Preferably, the controller includes a processing means to process the temperature sensitive input signals in accordance with a predetermined algorithm. Thus, particularly advanced forms of heat control techniques can be applied to an already installed heating system. Conveniently, the control means comprises a logic array.

An example of the invention will now be described with reference to the accompanying drawing. The drawing illustrates a heating system controller embodying the present invention. Heating system 1 includes, for example, a number of mixer valves or diverter valves, circulation flow controls, a controllable heat source, and pump controls. All of these elements of the heating system include suitable electrically operated actuators.

A series of temperature sensing elements 2 provide an indication of the temperature external to the heating system, the temperature of the space heated by the system, a reference temperature (typically the temperature of the heat transfer medium) and a set back temperature which as is known in the art is employed for night time set back. In addition to such temperature sensitive elements a timer 3 provides outputs to indicate that the central heating should be enabled, and/or the hot water service should be enabled. An additional element is responsive to hot water demand by users of the heating system, which can for example comprise a cylinder thermostat. Finally, a further element can be responsive to operating criteria of the heating source, for example detecting upper and lower temperature limits of an oilfired boiler.All the inputs from elements 3 to 5 can either be low voltage or mains.

The heating system controller comprises a logic array 6 having outputs connected to drivers 7 for operating the various elements of the heating system 1. The elements 3 to 5 which produce time varying output responses are fed directly into the logic array 6 whereas the outputs from the temperature sensors 2 are fed through a processing unit 8 prior to being relayed to the logic array 6. The processing unit 8 can for example comprise an analogue system to evaluate flow temperatures for the building having the heating system therein and can also average various space temperatures as is known in the art.

The logic array 6 includes a look-up table containing a number of directing instructions for actuating the driver units 7 to operate the various elements of the system 1. Different pages of instructions are examined depending upon the input values fed from elements 3 to 5 and 8. All these inputs are continuously presented to the logic array which after accessing the appropriate page of system directing instructions initiates the driver to operate the appropriate elements of the heating system.

The logic array 6 has an EPROM which stores a series of such pages of system directing instructions as a look-up table. The series of pages of instructions correspond to the required operating instructions for a plurality of different heating systems. A number of manually adjustable inputs A to D can be altered which by means of the logic array prevents access to pages of the look-up table. By adjusting the inputs A to D correctly the logic array 6 can be restricted to access only the particular pages of system directing instructions suitable for the heating system 1 connected to the driver element 7. If a different heating system is connected to the driver element 7 then the inputs A to D can be again varied so as to now prevent access to the pages suitable for heating system 1 but to allow access to the pages of system directing instructions suitable for the new heating system.

It will therefore be seen that all external components from the known heating system are directly connected to the heating system controller with a minimum of external interwiring. Only one controller type is required regardless of the heating system to which it is connected. By having a logic array the electrical environment for the heating system controller is less critical and the operation is effectively D.C. so it is easily immunised against electrical noise. The inputs A to D can be adjusted for the particular heating system by reading of miniature punched or conductive cards or switches or a combination of cards and switches. As an example, a comination of 32k EPROM can be employed within the logic array to provide 4k x 8 channels of output options.In a preferred embodiment the logic array includes means to fit to the elements 3 to 5 which can either be mains and/or low level and the driver outputs can be volt-free.

Consequently the heating system controller of the invention can be applied to control gas, oil, solid fuel electric or heat pump energy sources merely by adjusting the inputs A to D. Other forms of inputs can also be employed. Distribution can be by means of electricity, hot water or warm air and emission can be by warm air, radiators (with or without fan), underfloor or ceiling panels. The control of such elements will already be listed in the system directing instructions stored in the EPROM. It will be apparent that this makes the heating system controller of the invention particularly suitable for retrofitting without the necessity to reconfigure the heating system to suit the controller. It will be apparent that a microprocessor based system can be employed as an alternative to the logic array.

It will be apparent that if suitable pages for a system are not available on the logic array, an alternative logic array can be employed with other pages for different heating systems.

Claims

1. A heating system controller for connecting to control any one of a plurality of heating systems and comprising: store means storing a look-up table of system directing instructions for said plurality of heating systems; control means connected in use to receive both time varying and temperature sensitive input signals to indicate for said one heating system the user and system heat demand together with the cause thereof and the control menas in response thereto accessing said store means to retrieve system directing instructions dependant on said input signals; and output means connected to the control means to receive the retrieved system directing instructions to produce output signals for directing operation of elements of said one heating system; wherein the control menas includes access variation means manually adjustable to define said one heating system; whereby the access variation means restricts the control means access to said look-up table to system directing instructions relating only to that one heating system.

2. A controller as claimed in Claim 1 including processing means to process the temperature sensitive input signals in accordance with a predetermined algorithm.

3. A controller as claimed in Claim 1 or 2 wherein the control means comprises a logic array.

4. A controller as claimed in any preceding claim wherein said access variation means includes means for reading information stored on hard copy which defines said one heating system.

5. A controller as claimed in any preceding claim wherein said store means comprises an EPROM.

6. A heating system control for connecting to control any one of a plurality of heating systems substantially as herein described with reference to the accompanying drawing.