Stirling cycle machine

Abstract

An external combustion engine including a burner element, a heater head, a piston cylinder containing a piston, a cooler and a crankcase. The crankcase includes a crankshaft, a piston rod connected to the piston, a drive mechanism for converting the linear motion of the piston rod to rotary motion of the crankshaft and a linear cross-head bearing that is connected rigidly to the piston rod at one end and to the drive mechanism at the other end. Also the external combustion engine includes a piston clearance seal and a piston rod seal unit that has floating rod seals. The piston includes a inner dome to reduce axial heat transfer via radiation and convection.

1 - 29 . (canceled) 
     
     
         30 . A method for managing operation of a heating element in an external combustion engine, the heating element having at least one burner and an associated combustion chamber, the method comprising:
 initiating a start-up mode for achieving ignition in the combustion chamber, the startup mode further comprising;
 setting a blower speed to a first speed; 
 supplying a fuel to achieve a first fuel-air ratio; 
 attempting ignition using at least one ignitor; 
 detecting presence of a flame, and 
 resetting the start-up mode when the flame is not detected after a trial period; 
 switching to an operation mode when the flame is detected, the operation mode further comprising; 
 increasing the blower speed to support the flame in the combustion chamber; 
 supplying the fuel to achieve a second fuel-air ratio; 
 monitoring the operation of the external combustion engine to check for one or more pre-determined failsafe conditions, the one or more pre-determined failsafe conditions divided into a first set and a second set; 
 switching to a shut-off mode on determining one or more pre-determined failsafe conditions in the first set, and 
 switching to a stop mode on determining one or more failsafe conditions in the second set. 
   
     
     
         31 . The method according to  claim 30 , wherein detecting presence of the flame in the heating element comprises using an ultraviolet sensor. 
     
     
         32 . The method according to  claim 30 , wherein detecting presence of the flame in the heating element comprises sensing an oxygen level in an exhaust of the combustion chamber. 
     
     
         33 . The method according to  claim 30 , wherein detecting presence of the flame in the heating element comprises sensing a temperature. 
     
     
         34 . The method according to  claim 30 , wherein resetting the start-up mode further comprises blowing out a remaining quantity of the fuel from the combustion chamber and in the exhaust. 
     
     
         35 . The method according to  claim 30 , wherein the pre-determined first set of failsafe conditions comprises exceeding a predetermined temperature range of the external combustion engine. 
     
     
         36 . The method according to  claim 30 , wherein the pre-determined first set of failsafe conditions comprises exceeding a predetermined oxygen level range. 
     
     
         37 . The method according to  claim 30 , wherein the pre-determined first set of failsafe conditions comprises failure to detect the presence of the during the operation mode. 
     
     
         38 . The method according to  claim 30 , wherein the pre-determined first set of failsafe conditions comprise exceeding a speed range of the external combustion engine. 
     
     
         39 . The method according to  claim 30 , wherein the pre-determined first set of failsafe condition comprises exceeding a cooler temperature range in the external combustion engine. 
     
     
         40 . The method according to  claim 30 , wherein the pre-determined first set of failsafe condition comprises exceeding a generator temperature range in the external combustion engine. 
     
     
         41 . The method according to  claim 30 , wherein the pre-determined first set of failsafe condition comprises a repeated failure in igniting the flame. 
     
     
         42 . The method according to  claim 30 , wherein the pre-determined second set of failsafe conditions comprises a fall in a power output of the external combustion engine below a predetermined power value. 
     
     
         43 . The method according to  claim 30 , wherein the pre-determined second set of failsafe conditions comprises a fall in an oil pressure inside a crankcase of the external combustion engine below a predetermined crankcase oil pressure. 
     
     
         44 . The method according to  claim 30 , wherein the pre-determined second set of failsafe conditions comprise a decrease in an airlock pressure differential of the external combustion engine below a predetermined airlock pressure differential value. 
     
     
         45 . The method according to  claim 30 , wherein switching to the shut-off mode comprises stopping the supply of fuel. 
     
     
         46 . The method according to  claim 30 , wherein switching to the stop mode comprises stopping the supply of fuel and commanding the engine speed to approximately zero. 
     
     
         47 . A method for managing operation of a heating element in an external combustion engine, the heating element having at least one burner, an associated combustion chamber and an associated prechamber, the method comprising:
 initiating a start-up mode for achieving ignition in a prechamber, the startup mode further comprising;
 setting a blower speed to input air at a first speed; 
 supplying a fuel to achieve a first fuel-air ratio; 
 attempting ignition using at least one ignitor; 
 detecting presence of a flame in the prechamber, 
 monitoring an incoming air temperature in the combustion chamber, and 
 increasing the blower speed for advancing the flame from the prechamber to the combustion chamber when the flame is detected and the incoming air temperature exceeds a predetermined value, and
 switching to an operation mode to support the flame in the combustion chamber, the operation mode further comprising; 
 
 supplying the fuel to achieve a second fuel-air ratio, and 
 monitoring a plurality of failsafe conditions in the combustion chamber. 
   
     
     
         48 . The method according to  claim 47 , wherein detecting presence of the flame in the prechamber comprises using an ultraviolet sensor. 
     
     
         49 . The method according to  claim 47 , wherein detecting presence of the flame in the prechamber comprises sensing an oxygen level in an exhaust of the combustion chamber. 
     
     
         50 . The method according to  claim 47 , wherein detecting presence of the flame in the prechamber comprises sensing a temperature. 
     
     
         51 . The method according to  claim 47  further comprises increasing the flow of fuel when the increasing the blower speed. 
     
     
         52 . The method according to  claim 47  wherein the set of failsafe conditions comprises a first set and a second set; 
     
     
         53 . The method according to  claim 52  further comprising switching to a shut-off mode on confirming one or more pre-determined failsafe conditions in the first set. 
     
     
         54 . The method according to  claim 52  further comprising switching to a stop mode on confirming one or more failsafe conditions in the second set.