VEHICLE HEATERS AND CONTROLS THEREFOR
First Claim
1. A heater for a liquid, the heater having a combustion chamber, a jacket for the liquid extending about the combustion chamber and a burner head assembly connected to the combustion chamber, the burner head assembly including a housing having a burner mounted thereon and a hollow interior, a control module and a fan being mounted in the hollow interior, the fan being connected to an electric motor, a compressor and a fuel pump being mounted on the housing, the compressor and the fuel pump being operatively connected to the electric motor, the control module including a speed control for the motor which maintains the heater at a specified level of operation.
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0 Petitions
Accused Products
Abstract
A heater for a liquid has a combustion chamber, a jacket for the liquid extending about the combustion chamber and a burner head assembly connected to the combustion chamber. The burner head assembly includes a housing having a burner mounted thereon and a hollow interior. A control module and a fan are mounted in the hollow interior, the fan being connected to an electric motor. A compressor and a fuel pump are mounted on the housing and are operatively connected to the electric motor. The control module may include controls for exercising components of the heater prior to combustion, thereby verifying operation of these components. Preferably there is a speed control for the motor, such as a closed loop speed control which regulates motor speed and accordingly output of the heater. Preferably there is a backup system using a lookup table in the event that the closed loop speed control fails. Also preferably there is provision for monitoring flame sensor functionality by providing an indicator light which mirrors operation of the flame sensor. The heater may have a selective soft start for the coolant pump which operates only when required so as to reduce unnecessary chatter on the motor relay. A system is also provided for distinguishing true overcurrent faults from overcurrents arising from voltage changes during starting of the vehicle engine. Reignition algorithms are provided to restart the burner in the event of flame sputters caused, for example, by fuel bubbles, but shut off the heater in the event that the fuel is truly cut off.
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Citations
45 Claims
- 1. A heater for a liquid, the heater having a combustion chamber, a jacket for the liquid extending about the combustion chamber and a burner head assembly connected to the combustion chamber, the burner head assembly including a housing having a burner mounted thereon and a hollow interior, a control module and a fan being mounted in the hollow interior, the fan being connected to an electric motor, a compressor and a fuel pump being mounted on the housing, the compressor and the fuel pump being operatively connected to the electric motor, the control module including a speed control for the motor which maintains the heater at a specified level of operation.
- 17. A heater for a liquid, the heater having a combustion chamber, a jacket for the liquid extending about the combustion chamber and a burner head assembly connected to the combustion chamber, the burner head assembly including a housing having a burner mounted thereon and a hollow interior, a control module and a fan being mounted in the hollow interior, the fan being connected to an electric motor, a compressor and a fuel pump being mounted on the housing, the fuel pump and the compressor being operatively connected to the electric motor, the control module including controls for exercising components of the heater prior to combustion, thereby verifying operation of these components.
- 19. A heater for a liquid, the heater having a combustion chamber, a jacket for the liquid extending about the combustion chamber and a burner head assembly connected to the combustion chamber, the burner head assembly including a housing having a burner mounted thereon and a hollow interior, a control module and a fan being mounted in the hollow interior, the fan being connected to an electric motor, a compressor and a fuel pump being mounted on the housing, the compressor and the fuel pump being operatively connected to the electric motor, a flame sensor positioned in the housing to sense combustion in the combustion chamber, and an indicator mounted on the housing and operatively connected to the flame sensor to indicate when the flame sensor is sensing light.
- 21. A heater for a liquid, the heater having a combustion chamber, a jacket for the liquid extending about the combustion chamber and a burner head assembly connected to the combustion chamber, the burner head assembly including a housing having a burner mounted thereon and a hollow interior, a control module and a fan being mounted in the hollow interior, the fan being connected to an electric motor, a compressor and a fuel pump being mounted on the housing, the compressor and the fuel pump being operatively connected to the electric motor, a electric coolant pump connected to the jacket and a pump current modulator which modulates current supplied to the pump when current supply to the modulator is above a specified current and supplying an unmodulated current to the pump when current supplied to the modulator is below the specified current.
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28. A method of differentiating overcurrent faults from normal current conditions in an apparatus intended to be mounted to a vehicle and connected to the electrical system thereof, the method comprising monitoring for an overcurrent condition, monitoring voltage levels and determining whether there is a decrease in voltage relative to time exceeding a first specified value of dV/dT, or whether there is an increase in voltage relative to time exceeding a second specified value of dV/dT, declaring no overcurrent fault where there is said decrease in voltage exceeding the first specified value within a first specified time prior to an overcurrent condition or if there is an increase in voltage exceeding the second specified value within a second specified time of the overcurrent condition, and declaring an overcurrent fault where there is an overcurrent condition, but no such decrease in voltage or increase in voltage within the specified times.
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29. The method as claimed in claimed 28 wherein the apparatus is a heater and the method differentiates overcurrent events resulting from the vehicle being started from overcurrent events indicating a fault.
- 30. An apparatus for differentiating overcurrent faults from normal current conditions in a device intended to be mounted to a vehicle and connected to the electrical system thereof, the apparatus comprising controls which monitor for overcurrent conditions, monitor voltage levels and determine whether there is a decrease in voltage relative to time exceeding a first specified value of dV/dT, or whether there is an increase in voltage relative to time exceeding a second specified value of dV/dT, declaring no overcurrent fault where there is said decrease in voltage exceeding the first specified value within a first specified time prior to an overcurrent condition or if there is an increase in voltage exceeding the second specified value within a second specified time of the overcurrent condition, and declaring an overcurrent fault where there is no such decrease in voltage or increase in voltage within the specified times.
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32. A vehicle fitted with a fuel-powered heater for coolant, the heater having a combustion chamber, a jacket for the coolant extending about the combustion chamber and a burner head assembly connected to the combustion chamber, the burner head assembly including a housing having a burner mounted thereon and a hollow interior, a control module and a fan being mounted in the hollow interior, the fan being connected to an electric motor, a compressor and a fuel pump being mounted on the housing, the control module including controls for differentiating overcurrent faults from normal current conditions, the controls monitoring for overcurrent conditions and voltage levels and determining whether there is a decrease in voltage relative to time exceeding a first specified value of dV/dT, or whether there is an increase in voltage relative to time exceeding a second specified value of dV/dT, declaring no overcurrent fault where there is said decrease in voltage exceeding the first specified value within a first specified time prior to an overcurrent condition or if there is an increase in voltage exceeding the second specified value within a second specified time of the overcurrent condition, and declaring an overcurrent fault where there is an overcurrent condition, but no such decrease in voltage or increase in voltage within the specified times.
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33. The vehicle as claimed in claimed 30 wherein the controls differentiate overcurrent events resulting from the vehicle being started from overcurrent events indicating a fault.
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34. A method for determining whether a fault has occurred in a device having a fuel burning with a flame and an ignitor for igniting the flame, the method comprising the steps of:
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sensing periodically whether or not a flame is present; registering a flame on event if the flame is present; actuating the ignitor if no flame is present; registering a flame out event if no flame is present after the ignitor is actuated; and indicating that a fault has occurred when a first plurality of flame out events occurs before a second plurality of flame on events occurs. - View Dependent Claims (35, 36, 37)
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38. An apparatus for determining whether a fault has occurred in a device having a fuel burning with a flame and an ignitor for igniting the flame, the apparatus comprising:
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a flame sensor which periodically senses whether or not a flame is present; a first memory which stores a flame on event if the flame is present; means for actuating the ignitor if no flame is present; a second memory which stores a flame out event if no flame is present after the ignitor is actuated; and a control device which indicates that a fault has occurred when a first plurality of flame out events occurs before a second plurality of flame on events occurs. - View Dependent Claims (39, 40, 41)
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42. A heater for a liquid, the heater comprising a combustion chamber;
- a jacket for the liquid extending about the combustion chamber;
a burner head assembly connected to the combustion chamber, the burner head assembly including a housing having a burner mounted thereon and a hollow interior;
a control module; and
a fan mounted in the hollow interior, the fan being connected to an electric motor, a compressor being mounted on the housing and operatively connected to the electric motor; and
a flame sensor for sensing the presence or absence of a flame in the combustion chamber, the control module including controls for determining whether a fault has occurred, the controls periodically checking the flame sensor to determine whether or not a flame is present, a first memory which registers a flame on event if the flame is present, the controls actuating the ignitor if no flame is present, a second memory which registers a flame out event if no flame is present after the ignitor is actuated, and the control module indicating that a fault has occurred when a first plurality of flame out events occurs before a second plurality of flame on events occurs. - View Dependent Claims (43, 44, 45)
- a jacket for the liquid extending about the combustion chamber;
Specification