Multi-phase modular comfort controlled heating system

A gas-fired system for heating an enclosed space, comprising:

• a heating chamber;
• a blower for driving air through the heating chamber to said space;
• first heat exchanger means disposed in said heating chamber for transferring heat from heated water contained therein to the air in said chamber, said first heat exchanger having an outlet and an inlet;
• a plurality of gas-fired burner assemblies each including:
• a housing having a vent opening for exhausting combustion gases to the atmosphere;
• a burner heat exchanger mounted in the housing for carrying the water for heating;
• and
• a gas burner mounted in the housing for heating the water in the burner heat exchanger;
• a water pump for circulating the water in a closed loop between said first heat exchanger means and said plurality of burner heat exchanger means, the outlet of the first heat exchanger means being coupled to its inlet by said closed circulation loop including said plurality of burner heat exchanger means and said water pump;
• means for measuring the temperature of the air in the space into which air from the heating chamber is exhausted;
• firing means for individually firing the gas burner in each burner assembly to effect heating of the associated burner heat exchanger and water circulating therethrough to effect incremental increase in the heat transferred to the water circulated through said first heat exchanger means;
• and
• means for comparing said measured air temperature with a reference temperature and for activating the firing means to fire one or more of said burners as a function of the incremental heat required to maintain the temperature in said space at said reference temperature.

A gas-fired, multi-phase heating system for a space, comprising:

• a heating chamber;
• means for forcing air through the chamber and to said space;
• a first heat exchanger for transferring heat from a heated fluid to the air in said chamber, said first heat exchanger being mounted in the chamber and having an outlet and an inlet;
• a plurality of gas-fired burner assemblies each including:
• a housing defining an upper chamber having a vent opening for exhausting combustion gases and defining a lower chamber,
• a burner heat exchanger mounted in the housing intermediate the upper and the lower chamber for transferring heat to the fluid contained therein, and
• a gas burner for heating a fluid in the burner heat exchanger mounted in the lower chamber of the housing, which lower chamber in a typical crosssection tapers from the general vicinity of the gas burner to the location of the burner heat exchanger, whereby heated combustion gases from the gas burner are focused on the burner heat exchanger;
• circulating means for circulating the fluid in the first heat exchanger through the burner heat exchangers and back to the first heat exchanger, the outlet of the first heat exchanger being coupled to its inlet by the burner heat exchangers and said circulating means;
• means for measuring the temperature of the air in the space into which air from the heating chamber is exhausted;
• firing means for individually firing the gas burner of each said burner assembly to effect heat transfer to the fluid circulating through the burner heat exchanger associated therewith to thereby change the heat transferred to said first heat exchanger in discrete increments;
• and
• means for comparing said measured air temperature with a reference temperature and for activating the firing means to fire different numbers of said gas burners in accordance with the magnitude of the difference between said temperatures.

A heating arrangement, comprising:

• a heating chamber;
• means for forcing a first fluid from the heating chamber to a second chamber;
• a first heat exchanger for carrying a heated second fluid, said first heat exchanger being mounted in the heating chamber and having an outlet and an inlet;
• a plurality of burner assemblies each including:
• a housing,
• a burner heat exchanger mounted in the housing for carrying said second fluid and for transferring heat to said second fluid, and
• a burner mounted in the housing for heating that portion of said second fluid in the burner heat exchanger;
• means for circulating said second fluid from the first heat exchanger through all the burner heat exchangers and back to the first heat exchanger, the outlet of the first heat exchanger being coupled to its inlet by the burner heat exchangers and said circulating means;
• means for measuring the temperature in said second chamber;
• firing means for individually firing the burner of each said burner assembly;
• means for comparing said second chamber temperature with a selected reference temperature and for activating said firing means to fire one or more of said burners according to the difference between said temperatures to effect an incremental increase in the temperature of said second fluid circulating through said first heat exchanger in response to the firing of each burner;
• a clock;
• means for storing a plurality of reference temperatures and an associated time and for selecting a reference temperature from the plurality of reference temperatures dependent upon the time associated with the clock.

A method for heating an enclosure to maintain the temperature of the enclosure generally uniform by burning fuel while optimizing the utilization of the fuel, comprising the steps of:

• (a) locating a plurality of spaced apart modular burner assemblies in a parallel array so as to define a first assembly and an oppositely disposed last assembly, each of said burner assemblies including
• a walled housing,
• heat exchanger means for transferring heat to a first fluid, and
• burner means mounted in said housing for heating said heat exchanger means, whereby the heat produced by said burner means is used to increase the temperture of the first fluid;
• (b) circulating substantially all of said first fluid in parallel through all said burner heat exchangers and then circulating the fluid flowing out of said burner heat exchangers through said enclosure in a generally closed loop, said fluid entering said burner heat exchangers at one end of said array adjacent said first assembly and leaving at the opposite end of the array adjacent said last assembly;
• (c) transferring at least a portion of the heat added to the circulating first fluid from said incrementally fired burner assemblies to the interior of said enclosure, whereby heat is transferred to said fluid by a forced circulation system disposed in a reverse parallel flow relationship;
• (d) sizing the burner assemblies such that the steady state thermal energy produced by all of said burner assemblies when transferred to the interior of said enclosure by the forced circulation of said first fluid being generally equal to that heat transferred from the interior of said enclosure to the exterior of said enclosure for a selected first temperature difference between the interior and the exterior of said enclosure, the steady state thermal energy produced by one of said burner assemblies when transferred to the interior of said enclosure through the forced circulation of said first fluid being generally equal to the heat transferred from the interior of said enclosure to the exterior of said enclosure for a selected second temperature difference between the interior of said enclosure and the exterior of said enclosure, said second temperature difference being a fractional part of said first temperature difference, whereby the temperature in said enclosure is maintained relatively constant by firing at least one and less than all of said burner assemblies when said temperature difference has a value generally less than said first temperature difference and greater than or equal to said second temperature difference;
• (e) measuring the temperature at the interior of said enclosure;
• (f) comparing the temperature at the interior of said enclosure with a selected reference temperature;
• (g) activating one or more of said burner assemblies according to the difference between said reference temperature and the temperature at the interior of said enclosure, said last burner assembly being activated when the difference in temperature between said reference temperature and the exterior of said enclosure is generally greater than said second temperature difference, whereby heat is transferred to the interior of said enclosure almost instantaneously;
• (h) operating at least one burner assembly at its highest combusion efficiency during a substantial portion of the heating operation to minimize start-up losses, and standby losses;
• (i) activating additional burner assemblies one at a time in response to the difference between said reference temperature and the temperature at the interior of said enclosure when the heat lost from said enclosure exceeds the amount of heat transferred to the interior by the forced circulation of said first fluid, all of said burner assemblies being activated when the difference between said reference temperature and the exterior of said enclosure is generally greater than said first temperature difference, whereby the interior temperature of said enclosure is maintained relatively constant by changing the heat transferred to the interior of said enclosure in discrete increments, each increment being generally a fraction of the total energy transferred to said enclosure when all of the assemblies burner are operated;
• and
• (j) sequentially deactivating said burner assemblies one at a time when the heat added to said enclosure exceeds the heat lost to the exterior of the enclosure.

A heating system for an enclosure, comprising:

• (a) an array of spaced apart modular burner assemblies each including
• a walled housing,
• a burner heat exchanger carried by said housing for ducting a first fluid through said housing and for transferring the heat therein to said first fluid, and
• burner means, mounted in said housing, for heating the interior of said housing, whereby the heat produced by said burner means is used to heat said first fluid flowing through said housing;
• (b) forced circulation heating means for circulating substantially all of the mass of that portion of said first fluid to be heated in parallel through said burner heat exchangers and all of the fluid flowing out of said burner heat exchangers through said enclosure, said forced circulation means defining a plurality of conduit elements the volume of which is on the order of the volume of said burner heat exchangers, whereby the time rate of temperature change at the interior of said enclosure due to the firing of one additional burner means is proportional to the time rate of flow of said first fluid, startup losses are minimized, and each gas burner is operated at its highest combustion efficiency soon after being placed in operation;
• (c) measuring means for measuring the temperature at the interior of said enclosure;
• (d) firing means for individually firing the burner means in each of said burner assemblies;
• (e) comparison means, operatively associated with said measuring means and said firing means, for comparing the temperature at the interior of said enclosure with a selected reference temperature and for activating and de-activating one or more of said firing means sequentially and cumulatively according to the difference between said reference temperature and the temperature at the interior of said enclosure to increase the heat transferred to the interior of said enclosure in discrete increments and maintain the interior temperature of said enclosure relatively constant with at least one of said burner means being operated at its highest combustion efficiency, each subsequent firing means being activated by said comparison means when the heat lost from said enclosure exceeds the amount of heat transferred to its interior by said forced circulation means by said burner means then activated, the relative volume of fluid occupying the non-activated burner assemblies decreasing in discrete fractional amounts as the relative temperature difference between the circulating fluid in the non-activated burner assemblies and the interior of the associated walled housing increases as additional burner assemblies are placed in service, whereby the relative amount of standby losses does not substantially increase,
• the activated burner assemblies being sequentially de-activated when the heat added to said enclosure exceeds the heat lost.

A heating system for an enclosure, comprising:

• (a) an array of spaced apart modular burner assemblies each including
• a walled housing,
• a burner heat exchanger carried by said housing for ducting a first fluid through said housing and for transferring the heat therein to said first fluid, and
• burner means, mounted in said housing, for heating the interior of said housing, whereby the heat produced by said burner means is used to heat said first fluid flowing through said housing;
• (b) forced circulation heating means for circulating substantially all of the mass of that portion of said first fluid to be heated in parallel to contact said burner heat exhangers and for circulating all of the fluid flowing from said burner heat exchangers to effect heating of said enclosure, whereby the time rate of temperature change at the interior of said enclosure due to the firing of one additional burner means is proportional to the time rate of flow of said first fluid, startup losses are minimized, and each gas burner is operated at its highest combustion efficiency soon after being placed in operation;
• (c) measuring means for measuring the temperature at the interior of said enclosure;
• (d) firing means for individually firing the burner means in each of said burner assemblies;
• (e) comparison means, operatively associated with said measuring means and said firing means, for comparing the temperature at the interior of said enclosure with a selected reference temperature and for activating and de-activating one or more of said firing means sequentially and cumulatively according to the difference between said reference temperature and the temperature at the interior of said enclosure to increase the heat transferred to the interior of said enclosure in discrete increments and maintain the interior temperature of said enclosure relatively constant with those of said burner means having been fired being operated at their highest combustion efficiency, each subsequent firing means being activated by said comparison means when the heat lost from said enclosure exceeds the amount of heat transferred to its interior in response to the burner means then activated, the relative volume of fluid in contact with the non-activated burner assemblies decreasing in discrete fractional amounts as the relative temperature difference between the circulating fluid in contact with the non-activated burner assemblies and the interior of the associated walled housing increases as additional burner assemblies are placed in service, whereby the relative amount of standby losses does not substantially increase,
• the activated burner assemblies being sequentially de-activated when the heat added to said enclosure exceeds the heat lost.