Device and Method for Operational and Safety Control of a Heat Engine

Abstract

A device and a method are for the operational and safety control of a heat engine, which has a working-fluid path including a high-pressure path and a low-pressure path. The heat engine uses a condensable working fluid which, at least in part of the high-pressure path, is in the liquid phase. A fluid-drainage path, which is selectably open or closed, is connected to a portion of the high-pressure path in which the working fluid is mainly in the liquid phase.

1 . A heat engine which has a working-fluid, path including a high-pressure path and a low-pressure path, the heat engine using a condensable working fluid, which, at least in part of the high-pressure path, is in the liquid phase, wherein a fluid-drainage path, which is selectably open or closed, is connected to a portion of the high-pressure path in which, during normal operation, the working fluid is mainly in the liquid phase. 
     
     
         2 . The heat engine in accordance with  claim 1 , wherein the fluid-drainage path is connected to the high-pressure path at a connection point which is located downstream of the fluid pump. 
     
     
         3 . The heat engine in accordance with  claim 1 , wherein, in its downstream portion, the fluid-drainage path is connected to the low-pressure path. 
     
     
         4 . The heat engine in accordance with  claim 1 , wherein the fluid-drainage path is provided with a drain valve. 
     
     
         5 . The heat engine in accordance with  claim 4 , wherein the drain valve is closed to fluid flow in its activated state and is open to fluid flow in its non-activated state. 
     
     
         6 . A method for the operational and safety control of a heat engine, which has a working-fluid path including a high-pressure path and a low-pressure path, the heat engine using a condensable working fluid, which, at least in part of the high-pressure path, is in the liquid phase, wherein the method comprises:
 providing the heat engine with a fluid-drainage path which is selectably open or closed, and which is connected to a portion of the high-pressure path in which, during normal operation, the working fluid is mainly in the liquid phase;   detecting an operational condition in the heat engine that may cause working fluid present in the high-pressure path of the heat engine to reach an undesirably high pressure and/or an undesirably high temperature, or, detecting that the working, fluid present in the high-pressure path has reached an undesirably high pressure and/or an undesirably high temperature, or, detecting an operational condition in which it is otherwise desirable to stop the operation of the heat engine in the quickest way possible;   opening the fluid-drainage path; and   letting an amount of working fluid be drained and thereby evacuated from the high-pressure path via the fluid-drainage path.   
     
     
         7 . The method in accordance with  claim 6 , wherein the method comprises, providing the fluid-drainage path with a drain valve and driving the drain valve into its open position whenever there is a need to drain fluid from the high-pressure path. 
     
     
         8 . The method in accordance with  claim 6 , wherein the method comprises, letting an amount of working fluid be drained from the high-pressure path, the flow direction of the portion of the working fluid which is being evacuated and is still in the high-pressure path mainly having been reversed in relation to the flow direction during normal operation. 
     
     
         9 . The method in accordance with  claim 6 , wherein the method further comprises connecting the fluid-drainage path to the low-pressure path and letting the working fluid be drained from the high-pressure path to the low-pressure path. 
     
     
         10 . The method in accordance with  claim 9 , wherein the method comprises:
 letting working fluid be drained into the low pressure path at a connection point which is placed in one of the following positions in the low-pressure path;   upstream of a recuperator;   upstream of a condenser;   upstream of a working-fluid reservoir; or   on the working-fluid reservoir and with connection into it in terms of fluid.