Fuel-operated heater
AssigneeJ. Eberspächer GmbH & Co. KG
InventorsMichael Humburg, Harald Sailer, Andreas Alber
Life of this patent
Estimating the term…
Abstract
A fuel-operated heater, especially an auxiliary heater for a motor vehicle, with a fuel feed pump and/or with a combustion air fan, the heater, being operated in a predetermined lambda range. The heater is associated with a pressure sensor, by which the controllable fuel feed pump and/or the controllable combustion air fan can be energized via a control device. The pressure sensor may be arranged externally or also in the heater, especially on the pressure side of the fan. Not only changes in air pressure caused by atmospheric conditions, but also system-dependent changes in air pressure can be corrected in the case of the arrangement of a sensor on the pressure side of the fan.
Claims17
A process for operating a combustion heater, the process comprising the steps of:
- providing a combustion chamber;
- providing a fan means for delivering combustion air to said combustion chamber;
- providing a fuel means for delivering fuel to said combustion chamber;
- setting said fan means and said fuel means to operate the heater in a desired lambda range at an initial ambient pressure;
- measuring actual ambient pressure;
- determining an ambient difference between said actual ambient pressure and said initial ambient pressure;
- adjusting said fuel means to an amended setting based on said ambient difference to operate the heater in said desired lambda range;
- operating said fan means, and said fuel means with said amended setting, to cause combustion in said combustion chamber.
A process for operating a fuel-operated heater, the process comprising the steps of:
- providing a combustion chamber;
- providing an adjustable fuel feed pump connected to said combustion chamber;
- providing an adjustable combustion air fan connected to said combustion chamber;
- providing a pressure sensor arranged in said heater on a high pressure side of said fan for sensing ambient air pressure, sensor pressure and system back pressure;
- providing a control operating the heater according to a defined control having a defined control setting with relative settings of said air fan and said fuel feed pump based on an initial value of said ambient air pressure (po amb), an initial value of said sensor pressure (po sens) and an initial value of said system back pressure (po syst);
- operating said heater for a period with said fan shut off;
- operating said fan for a period with the fan in operation;
- changing said defined control from said control setting to a modified control setting with said feed pump frequency (f) reduced when both p sens is less than po sens when said heater is operated with said fan shut off and p sens is less than po sens when said heater is operated with the fan in operation;
- and
- changing said defined control from said control setting to a modified control setting with said feed pump frequency (f) increased when both p sens is greater than po sens when said heater is operated with said fan shut off and p sens is greater than po sens when said heater is operated with the fan in operation.
A combustion heater comprising:
- a combustion chamber;
- a fan means for feeding combustion air to said combustion chamber;
- a fuel means for delivering fuel to said combustion chamber;
- a pressure sensor means for measuring actual ambient pressure;
- control means for storing a setting of said fan means and said fuel means to operate the heater in a desired lambda range at an initial ambient pressure, said control means adjusting said setting of said fuel means based on a comparison of said initial ambient pressure and said actual ambient pressure.
Dependencies are inferred from the claim text.