Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23N—REGULATING OR CONTROLLING COMBUSTION
  • F23N1/00—Regulating fuel supply
  • F23N1/08—Regulating fuel supply conjointly with another medium, e.g. boiler water
  • F23N1/082—Regulating fuel supply conjointly with another medium, e.g. boiler water using electronic means
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24D—DOMESTIC- OR SPACE-HEATING SYSTEMS, e.g. CENTRAL HEATING SYSTEMS; DOMESTIC HOT-WATER SUPPLY SYSTEMS; ELEMENTS OR COMPONENTS THEREFOR
  • F24D19/00—Details
  • F24D19/10—Arrangement or mounting of control or safety devices
  • F24D19/1006—Arrangement or mounting of control or safety devices for water heating systems
  • F24D19/1009—Arrangement or mounting of control or safety devices for water heating systems for central heating
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24H—FLUID HEATERS, e.g. WATER OR AIR HEATERS, HAVING HEAT-GENERATING MEANS, e.g. HEAT PUMPS, IN GENERAL
  • F24H15/00—Control of fluid heaters
  • F24H15/10—Control of fluid heaters characterised by the purpose of the control
  • F24H15/144—Measuring or calculating energy consumption
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24H—FLUID HEATERS, e.g. WATER OR AIR HEATERS, HAVING HEAT-GENERATING MEANS, e.g. HEAT PUMPS, IN GENERAL
  • F24H15/00—Control of fluid heaters
  • F24H15/10—Control of fluid heaters characterised by the purpose of the control
  • F24H15/156—Reducing the quantity of energy consumed; Increasing efficiency
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24H—FLUID HEATERS, e.g. WATER OR AIR HEATERS, HAVING HEAT-GENERATING MEANS, e.g. HEAT PUMPS, IN GENERAL
  • F24H15/00—Control of fluid heaters
  • F24H15/20—Control of fluid heaters characterised by control inputs
  • F24H15/212—Temperature of the water
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24H—FLUID HEATERS, e.g. WATER OR AIR HEATERS, HAVING HEAT-GENERATING MEANS, e.g. HEAT PUMPS, IN GENERAL
  • F24H15/00—Control of fluid heaters
  • F24H15/20—Control of fluid heaters characterised by control inputs
  • F24H15/212—Temperature of the water
  • F24H15/219—Temperature of the water after heating
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24H—FLUID HEATERS, e.g. WATER OR AIR HEATERS, HAVING HEAT-GENERATING MEANS, e.g. HEAT PUMPS, IN GENERAL
  • F24H15/00—Control of fluid heaters
  • F24H15/20—Control of fluid heaters characterised by control inputs
  • F24H15/242—Pressure
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24H—FLUID HEATERS, e.g. WATER OR AIR HEATERS, HAVING HEAT-GENERATING MEANS, e.g. HEAT PUMPS, IN GENERAL
  • F24H15/00—Control of fluid heaters
  • F24H15/30—Control of fluid heaters characterised by control outputs; characterised by the components to be controlled
  • F24H15/355—Control of heat-generating means in heaters
  • F24H15/36—Control of heat-generating means in heaters of burners
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24H—FLUID HEATERS, e.g. WATER OR AIR HEATERS, HAVING HEAT-GENERATING MEANS, e.g. HEAT PUMPS, IN GENERAL
  • F24H15/00—Control of fluid heaters
  • F24H15/40—Control of fluid heaters characterised by the type of controllers
  • F24H15/414—Control of fluid heaters characterised by the type of controllers using electronic processing, e.g. computer-based
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23N—REGULATING OR CONTROLLING COMBUSTION
  • F23N2225/00—Measuring
  • F23N2225/08—Measuring temperature
  • F23N2225/19—Measuring temperature outlet temperature water heat-exchanger
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23N—REGULATING OR CONTROLLING COMBUSTION
  • F23N2225/00—Measuring
  • F23N2225/22—Measuring heat losses
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
  • F23N—REGULATING OR CONTROLLING COMBUSTION
  • F23N2227/00—Ignition or checking
  • F23N2227/10—Sequential burner running

Definitions

• the present invention relates to a method and apparatus for improving heating system efficiency, particularly in heating systems which utilize a boiler to heat a fluid such as water or steam for transfer of heat via a heat exchanger to a space to be heated.
• Heating systems utilizing burners and boilers are at their least efficient when starting up. Prior to achieving operating temperature, the burner burns less cleanly. Heating systems generally operate at their peak efficiency when they are fully loaded. But heating systems generally are sized for the area to be heated in such a fashion that the only time the boiler is properly matched to the heating load is when the outside temperature is the value for which the system was designed for. A system is usually sized for the worst case temperature conditions as expected in a given geographic area. The net effect of this is that whenever the outside temperature exceeds this design temperature, the boiler is oversized for the heating load and is thus less efficient. Evidence of this is the cycling on and off of the burner which heats the boiler.
• Boilers have, as part of their inherent design, a heating media which is transferred throughout the heating load as a means of transferring the heat and subsequently heating the area. This heating media has a mass which retains heat even after the boiler shuts down.
• Various schemes have been used to take advantage of this thermal inertia to prolong off times and run times under certain load conditions. 2
• time and water temperature controlled means to cause energization of the heater at the start of the off-peak period m case less than a predetermined fractional part of the water content of a tank is hot at the start of an off-peak period , to delay energization of the heater for an adjustably predetermined length of time after start of an off-peak period in case said predetermined fractional part of the water content is hot at the start of an off-peak period.”
• CONTROLLING HEATING BOILERS which purports to "measure the time between exceeding of the second temperature level and underpassmg of the first level” and “to delay the start of the heating means” on the next cycle, after a boiler thermostat call, for a time interval which is a function of the measured time.
• the patent refers also to detecting tap water temperature and stopping the delay below a predetermined tap water temperature
• the present invention seeks to reduce the number of cycles without measuring ambient temperatures or measuring or relying on past off times to calculate delays.
• the invention is a microprocessor controlled device which, when properly connected to a gas or oil fueled hot water or steam boiler will render the effect of more fuel efficiency (because of less total burner on time) which correlates directly to fuel, energy and money savings.
• the invention intercepts and interrupts the signal sent by the boiler's built-in thermostat, which activates the burner
• the boiler thermostat is still responsible for the maximum temperature setting of the boiler.
• the invention determines the optimum instance of allowing the electrical path to be completed and subsequent starting of the boiler's burner, by taking a temperature reading (by invention sensors located as close as possible to the discharge of the boiler and/or domestic hot water heating coil) at the instant of a "call for heat" by the boiler thermostat, and storing these readings in the invention. These stored readings are compared to those of subsequent temperature readings via the same sensor (s). When the desired amount of difference (user adjustable) between either of the temperature readings, as compared to its corresponding stored value, is surpassed the electrical circuit will be completed.
• the temperature sensors also perform 5
• the temperature sensor may be replaced or run in parallel with a pressure dependent switch or thermostat or any other means by which the sensor signal leads are electrically shorted when the desired minimum temperature is reached.
• the number of sensors is determined by the particular installation and depends on the application (i.e. Heating only, Heating and Domestic hot water generation, or Domestic Hot Water generation only.)
• the invention intercepts and interrupts the signal sent by the boiler's built-in pressuretroll and/or domestic hot water thermostat which activates the burner.
• the boiler's built-in pressuretroll/thermostat is never overridden by the invention, it is simply interrupted.
• the boiler pressuretroll is still responsible for the maximum pressure setting of the boiler and domestic hot water thermostat the maximum water temperature.
• the invention determines the optimum instance of allowing the electrical path to be completed and subsequent starting of the boiler's burner, by taking a pressure/temperature reading (by invention sensors located as close as possible to the discharge of the boiler and/or domestic hot water heating coil) at the instant of a "call for heat" by either the boiler pressuretroll or hot water thermostat, and storing these readings in the invention.
• the pressure/temperature sensor may be replaced or run in parallel with a pressure dependent switch, thermostat, pressuretroll or any other means by which the sensor signal leads are electrically shorted when the desired minimum pressure is reached.
• the number of sensors is determined by the particular installation and depends on the application, (i.e. Heating only. Heating and domestic.
• Fig 1 is a system diagram showing the invention installed in a heating system.
• Fig. 2 is a circuit diagram showing the invention installed m a boiler burner circuit .
• Fig. 3 is a circuit diagram of the control circuit of the invention.
• Fig. 4 is a set of graphs correlating various system temperatures, without and with the invention operating.
• a heating system As shown in Fig.l, a heating system, generally designated 2, is designed to heat a space 4.
• the system includes a boiler 6.
• Boiler 6 is fired by burner 8 for heating the boiler.
• the term boiler is conventionally used, whether or not the boiler actually boils water as m steam heat, or merely heats water as in forced hot water heating. 7
• Heat exchanger or radiator 18 is usually located remote from the boiler in space 4. Radiator 18 transfers heat to space 4
• Domestic hot tap water is created by passing cold water from the domestic water supply 19A through coil 19B which absorbs heat from fluid heat transfer medium 16 and outflows through domestic hot water outflow pipe 19C, when demanded, as by hot water tap 19D.
• radiator 18 In a forced hot water heating system the cooled water from radiator 18 returns via return pipe 22 and is pumped by circulator pump 24 back to boiler 6.
• Energy value sensor 26 is a thermostat in a forced hot water system or is a pressuretrol in a steam system. Energy value sensor 26 is within boiler 6 and senses a low energy, either temperature or steam pressure, at which boiler 6 requires more heat.
• the sensor 26 would switch on electrical power from power supply 27 which would supply and fire burner 8 to ignite the oil or gas and 8
• control circuit 28 is interposed between sensor 26 and burner 8 along wires 30 and 34. Control circuit 28 accomplishes the following steps:
• Control circuit 28 opens the circuit from sensor 26, switching the power to burner 8 off.
• outflow energy sensor means 38 should be a sensor capable of sending a signal usable by an electronic circuit.
• the energy value is temperature.
• temperature transducers such as a thermocouple, but the applicant presently prefers a thermistor mounted at the boiler outflow.
• said thermistor has an inherent non-linearity, with greater voltage drops at lower temperatures, which non- linearity serves as means for a control program to respond linearly to thermistor voltage while having non- linear and increased sensitivity to smaller temperature decreases at lower temperatures
• control program can logically induce non-linearity, making the system quicker to fire in response to lower energy drops at lower temperatures.
• the outflow energy sensor means 38 is a pressure sensor.
• Outflow energy sensor 38 senses an energy value of the outflow line 20 at boiler 6.
• Outflow energy sensor 39 senses an energy value of the domestic hot water outflow line 19C at boiler 6.
• Control circuit 28 continuously, or at frequent intervals, monitors the outflow energy values at sensors 38 and 39 .
• Control circuit 28 records the outflow energy values at a first time of the firing signal. When either sensor 38 or 39 communicates a sufficient voltage drop, below the value at the first time of the firing signal, to control circuit 28, circuit 28 allows the burner to fire.
• aomestic hot water ou r- w sensor 39 will not De provided or sensed or monitored by tne con rc
• Fig. 4 illustrates an outflow energy value over time without using tne present invention 40, and illustrates an outflow energy value over time s r.g tne present invention 42.
• ooiier temperature causes thermostat 26 (Fig. 1) to turn off Durner 8 at 180°F ana turn en ourr.er 3 at 170 C F.
• fig. 4 at time TO the ooiier nas ;ust snut off ana --r-e 44 decays slowly oecause tne water remains still inside r.e ooiier.
• Tl room temperature 45 has fallen to a lower limit 68°F ana space thermostat -u rig.
• Thermostat 50 stops the circulator pump 24 wnicn re ⁇ uc ⁇ s boiler load and cycling between T6 (Fig.4) and T7. But notice now 10 many boiler cycles 60 occur between T2 and T6. Each of these cycles has a start-up period of inefficient burning and greater air pollution.
• a s sncw ⁇ m Fig. 2 control circuit 28 interrupts the power supply from co -. ⁇ r t nermostat 26 to Durner 8, and serves as means for preven t ing t ne oo i. --.er energy value sensor from firing the boiler, mclu ⁇ ng a orea-c 4 7 m a power s_pply wire 48 between :
• Bu t vc t age on not wire 30 is sensed in Fig. 3 DV switc. means for actua t ion oy a voltage on the hot wire, which switch means is an elec t ronic circui t capaoie of a wide range of voltage inputs, preferably optoisola t or circui t 7 C
• the w i de range of voltage inputs is between 24 VAC and 240 VAC, wnicr. copes ⁇ -:: any heating system power supply known to the inven t or t nrougnou t the world.
• circuit 28 responds to the change by de-energizing relay 74 to its normally closed condition, and thereby supplying power to fire tr.e burner. (Since relay 74 is normally closed, a failure in the invention will result m normal operation of neatmg system 2.)
• -t can oe seen that, ⁇ y reacting to the outflow energy drop, the invention reacts to the present thermal load on the neatmg system.
• the invention a ⁇ apts itself to load cnanges immediately. Therefore, t can oe sai ⁇ t at the invention serves as self a ⁇ aptive means for reacting to imme ⁇ iate loa ⁇ cnanges to avoid reaenmg a Doiler energy value low limit.
• the -iicroprocesscr program follows on the next four pa ⁇ es .

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Computer Hardware Design (AREA)
• Control Of Steam Boilers And Waste-Gas Boilers (AREA)
• Control Of Combustion (AREA)
• Fluidized-Bed Combustion And Resonant Combustion (AREA)
• Heat-Pump Type And Storage Water Heaters (AREA)
• Regulation And Control Of Combustion (AREA)
• Steam Or Hot-Water Central Heating Systems (AREA)

Applications Claiming Priority (1)

Publications (3)

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• 1998
  • 1998-03-20 CN CN98813982A patent/CN1104590C/zh not_active Expired - Fee Related
  • 1998-03-20 AU AU67684/98A patent/AU742376B2/en not_active Ceased
  • 1998-03-20 CA CA002324462A patent/CA2324462C/en not_active Expired - Lifetime
  • 1998-03-20 AT AT98913036T patent/ATE540267T1/de active
  • 1998-03-20 EP EP98913036A patent/EP1077821B1/de not_active Expired - Lifetime
  • 1998-03-20 WO PCT/US1998/005625 patent/WO1999048713A1/en not_active Ceased
  • 1998-03-20 NZ NZ507617A patent/NZ507617A/xx not_active IP Right Cessation

Non-Patent Citations (2)

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