System and Method for Sampling Fluid From Piston Top Land Crevice of Piston Engine

摘要

A system and method for sampling fluid from a top land piston crevice of a reciprocating piston engine. Access into the crevice is via a length of tubing inserted into a bore through the piston wall. Two valves, first a relief valve and then a piloted check valve, operate together to capture a sample of fluid from the crevice at a time just before TDC of the piston on its compression stroke. The sampled fluid flows from the check valve into a sample container. The valves further cooperate to close fluid communication from the crevice after a sample is taken, which allows the engine to operate normally.

主权项

1. A system for sampling fluid from a top land piston crevice of a reciprocating piston engine, during operation of the engine, for delivery to analysis equipment, comprising:
a tubing having a first end that provides fluid communication into the crevice via a bore through the piston wall; a piloted check valve whose input end is connected to the second end of the tubing; a relief valve on the tubing between the crevice and the check valve, operable to open fluid flow from the crevice when a compression pressure of the engine results from a near top dead center position of the piston; a sample line connected to the output end of the check valve; a sample container for receiving fluid from the check valve via the sample line; wherein the piloted check valve is operable to close fluid communication between the crevice and the sample container just prior to a predetermined rise in combustion chamber pressure.