The crankcase of internal combustion engines is a source of blow-by gases arising from leakage at the piston rings, turbocharger seals, and valve stems. In engines equipped with a closed crankcase ventilation system (CCV), the crankcase gases are typically vented before the turbocharger inlet. If not regulated, the suction effect of the turbocharger would cause high vacuum in the crankcase.
Crankcase pressure
Too high crankcase vacuum would suck air and contaminates into the crankcase and overload the oil mist separator. Too high crankcase pressure would cause oil and gas leaks from the crankcase and cause engine shutdowns.
The optimum solution would be to have a regulated crankcase pressure. The UT99 Electronic Pressure Regulator (EPR) with flowmeter option (FlowSpin) was developed to maintain optimum crankcase pressure to ensure economical and sustainable engine operation. UT99 crankcase ventilation solutions reduce engine service frequency, increase operational lifetime, and enable advanced smart features including engine monitoring, predictive maintenance and diagnostics.
Electronic control
The EPR-CCV is a mechatronic throttle that controls crankcase pressure by regulating the open cross-section through which the blow-by flow can pass. The device must be supplied with the current crankcase pressure signal and the set pressure so that the internal control logic / data processing unit can adjust the throttle valve to the correct position. A spring-loaded mechanism ensures that the throttle opens in case of power or signal loss.
All EPR-CCVs feature identical port sizes and dimensions but use different throttle valve geometries that are chosen based on the blow-by flow rate and the actual pressure profile in the crankcase ventilation system. The functionality of the device can be expanded by the FlowSpin option that enables blow-by flow monitoring. Additional information on the requirements and properties of EPR-CCV and FlowSpin are listed in the specifications document.
Benefits
- EPR-CCV avoids unfavorable engine crankcase over-/under pressure resulting in less lube oil leakage as well as avoidance of oil contamination by suction from outside environment into the crankcase.
- EPR-CCV supports operational lifetime of oil mist filter as well as reduces backpressure.
- Low pressure drop of EPR-CCV (fully opened) enables compact and efficient oil mist filter designs.
- Various digital output signals via CANopen® bus communication:
- Useable for engine monitoring, maintenance, diagnosis
- ready for IoT and Cloud Analysis Platforms (IoT Gateway not included)
- Error detection: A rapid increase in crankcase pressure from e.g., a broken piston ring is not interfered by means of EPR-CCV.
- EPR-CCV is fail-safe. In the unlikely event of power loss, the regulator opens fully (spring loaded mechanism).
- Optional FlowSpin enables advanced engine and oil mist filter diagnosis
Blow-by flow measurement
The blow-by flow not only influences the operating behavior of the crankcase ventilation system, but also provides insights into engine wear. In addition, the blow-by flow can be used to detect and even predict engine malfunctions. Measuring this crucial parameter is a standard practice in engine development and presents the opportunity to enhance operational reliability in series applications.
With the FlowSpin for the EPR and the FlowSpin SA (stand-alone), UT99 offers two solutions that reliably determine the blow-by volume flow of engines up to 5 MW. The basic measuring principle is that of an impeller anemometer. Two different impeller geometries are available to optimally cover the expected volume flow range. The design of the FlowSpin enables a drastic reduction in the required run-in distance and ensures a linear relationship between impeller speed and blow-by volume flow.