Heating apparatus controlled to utilize lower cost energy

• US 5,700,993 A
• Filed: 03/15/1996
• Issued: 12/23/1997
• Est. Priority Date: 05/17/1993
• Status: Expired due to Fees

• Current Assignee: EA Technology Limited (EA Technology Ltd. /Exell & Sibley/)
• Original Assignee: EA Technology Limited (EA Technology Ltd. /Exell & Sibley/)
• Inventors: Reeves, John H., Counsell, John M.
• Primary Examiner(s): Paschall, Mark H.
• Application Number:
  US08/549,850
• Time in Patent Office: 648 Days
• Field of Search: 219/483-486, 219/497, 219/505, 219/508, 219/506, 219/501, 219/494, 392/339-345, 165/18, 165/2, 165/28
• US Class Current: 219/483
• CPC Class Codes: F24F 2130/00 Control inputs relating to environmental factors not covered by group F24F2110/00
• CPC Class Codes: F24F 2130/10 Weather information or forecasts
• CPC Class Codes: G05D 23/1923 using thermal energy, the cost of which varies in function of time
• CPC Class Codes: G05D 23/1934 each space being provided with one sensor acting on one or more control means
• CPC Class Codes: G05D 23/20 with sensing elements having variation of electric or magnetic properties with change of temperature G05D23/13 takes precedence

Abstract

A heating control apparatus for use in a heating system having heaters for heating at least one location and temperature sensors for measuring the temperature of each location is disclosed. The heating system is connected to an electricity supply having a tariff which varies with time. The heating control apparatus comprises a data receiving arrangement for receiving data on the tariff and weather prediction information. A selector is provided which is operable by a user to select the desired temperature for each location and a desired time and duration of the desired temperature. A controller includes a memory for storing information on the thermal characteristics of each location and the heaters and is responsive to the data, the measured temperature and the temperature selected by the user as well as the stored information to determine the times at which the heaters are to be energised. The controller then controls the heaters in order to achieve the desired temperature in each location.

Claims

1. Heating control apparatus for use in a heating system having electric heating means for space heating at least one location, said electric heating means comprising storage heating means and direct heating means provided at said location, and temperature measuring means for measuring the temperature at said location, said heating system being connected to an electricity supply having a cost profile indicating variations in electricity cost with time;

said heating control apparatus comprising data receiving means for receiving data on said cost profile and weather prediction information;

user selection means operable by a user to select a desired temperature for said location and a desired time and duration of said desired temperature;

information storage means for storing information defining the thermal response characteristics of said location and said electric heating means; and

control means responsive to said data received by said data receiving means, said temperature measuring means, said user selection means, and said stored information to determine the times at which each of said storage heating means and said direct heating means is energized, said control means being operative to control said heating means accordingly in order to achieve said desired temperature for said desired time and duration at said location, and to energize said storage heating means preferentially when the electricity cost is low.

2. Heating control apparatus as claimed in claim 1 wherein said control means is operative to control said direct heating means to only supply a small amount of the total heat input to said location in order to achieve said desired temperature at said location.

3. Heating control apparatus as claimed in claim 1 wherein said heating system includes respective said storage and direct heating means at each of a plurality of said locations and a respective said temperature measuring means for each said location, said user selection means being adapted to allow a user to select desired temperatures for each said location, and said control means being operative to independently control each said heating means to achieve the desired temperature in each said location.

4. Heating control apparatus as claimed in claim 1 wherein said control means is operative to use said stored information and said weather prediction information to calculate a predicted temperature for said location.

5. Heating control apparatus as claimed in claim 4 wherein said control means is operative to predict the electrical power required by said heating means to achieve said desired temperature by matching a predicted temperature for a power input with said desired temperature.

6. Heating control apparatus as claimed in claim 4 including feedback control means responsive to a difference between a said predicted temperature for said location and a measured temperature for said location to control said direct heating means to achieve said desired temperature at said location.

7. Heating control apparatus as claimed in claim 1 wherein said storage means is adapted to store respective model parameters for heating of said location by said storage heating means, said control means being operative to determine the relationship between direct heating power and measure temperature, and storage heating power and measured temperature using respective models which use respective said model parameters.

8. Heating control apparatus as claimed in claim 1 wherein said storage means is adapted to store values for coefficients of a set of weighted transfer functions.

9. Heating control apparatus as claimed in claim 4 wherein said control means is operative to compare the measured temperature at said location with the predicted temperature, and to modify said stored information adaptively to reduce any difference between the measured and predescribed temperatures.

10. Heating control apparatus as claimed in claim 1 wherein said control means is operative to control the energization of said heating means to reduce total energy consumption utilized in heating said location to achieve said desired temperature.

11. Heating control apparatus as claimed in claim 1 wherein said control means is operative to control the energisation of said heating means to preferentially utilise electricity which maximises the profit margin of the utility.

12. Heating control apparatus as claimed in claim 1 wherein said control means is operative to reduce a cost function comprising a weighted sum of at least two of the total cost, the energy consumption, and the inverse of the profit of the utility, the weights of the sum being selectable by a user.

13. Heating control apparatus as claimed in claim 12 wherein said control means includes weight selection means operable by a user to select the weights for the sum.

14. Heating control apparatus as claimed in claim 6 wherein said storage means contains a model of said thermal characteristics and said control means is operative to measure the power input to the direct heating means required to achieve said desired temperature and to modify said model to reduce said power.