A temperature sensor and a relative humidity sensor are placed in an environment allowing air to flow and are displaced in an upstream-downstream direction of the airflow. An absolute humidity acquisition unit acquires absolute humidity of air from outputs from the temperature sensor and the relative humidity sensor. A delay adjustment unit delays an output from one of the temperature sensor and the relative humidity sensor placed upstream and to reconcile change-behaviors of outputs from the temperature sensor and the relative humidity sensor in response to a state change in air. The absolute humidity acquisition unit acquires the absolute humidity based on the output from the other of the temperature sensor and the relative humidity sensor placed downstream and an output acquired from the one sensor placed upstream and delayed in the delay adjustment unit.

According to the conventional knowledge, a thermal humidity measurement device has problems in which the direction of air flow is limited to one direction is too hard to handle in securing the humidity responsiveness because there are limitations on the mounting direction of the thermal humidity measurement device and the state of air flow. An introduction guide protrudes from an air introduction surface to the outside of a measurement chamber, is parallel to a humidity introduction port surface, and has a portion not in contact with an inlet surface of a humidity introduction tube as seen from any direction to guide the flow of air to the humidity introduction tube from any direction of 360°.

To obtain a physical quantity detection apparatus that can reduce the outer shape of a housing in size. A physical quantity detection apparatus 300 detects a plurality of physical quantities of gas 30 to be measured flowing in a main passage 124. The physical quantity detection apparatus 300 has a housing 302 disposed in the main passage 124, a circuit substrate 400 insert molded in the housing 302, and a plurality of detection sensors 452, 453, 454, 455, and 456 each mounted on each of one face and the other face of the circuit substrate 400.

A humid air system (HAS) for reducing NOx emissions of an LPG-powered forklift and other heavy equipment is disclosed. A humid air system (HAS) uses distilled water and heat of exhaust to generate steam, injected at the intake air of the engine to increase humidity and reduce temperature and NOx emission. The system includes a pipe with a coiled-tube insert that is attached to the exhaust. A water pump connected to a solenoid valve supplies distilled water from a container to the exhaust coil, generating steam that is fed to a mixing box at the engine air intake in order to increase intake air humidity. A feedback control system controls the solenoid valve opening to adjust the water flow rate for maintaining humidity level between 90% to saturation.

A humid air system (HAS) for reducing NOx emissions of an LPG-powered forklift and other heavy equipment is disclosed. A humid air system (HAS) uses distilled water and heat of exhaust to generate steam, injected at the intake air of the engine to increase humidity and reduce temperature and NOx emission. The system includes a pipe with a coiled-tube insert that is attached to the exhaust. A water pump connected to a solenoid valve supplies distilled water from a container to the exhaust coil, generating steam that is fed to a mixing box at the engine air intake in order to increase intake air humidity. A feedback control system controls the solenoid valve opening to adjust the water flow rate for maintaining humidity level between 90% to saturation.

A device which measures a physical quantity of a gas flowing through a main passage is described. The device includes a flange for fixing to the main passage; a housing that protrudes toward an inside of the main passage from the flange; and a printed circuit board fixed to the housing on which a measuring element that measures the physical quantity is mounted. Wiring of the printed circuit board has a plurality of irregularities formed along one direction of a surface, and the wiring is arranged such that a formation direction of the irregularities is oriented along a protruding direction of the housing toward an inside of the main passage. The irregularities may be polishing marks formed using a cylindrical polishing wheel or rolling marks of the wiring of the printed circuit board.

A precleaner system for an air intake system. The precleaner system includes precleaners each having flow paths that induce a rotation to air flow and separate out particulate matter. The particulate matter is ejected from an outlet port in each of the flow paths and out of a dust ejector. The precleaned air is collected into a plenum from each of the precleaners. The precleaned air can flow from the plenum to a precleaner system outlet and the precleaned air can be received by an air intake system. A cover can be used to block air flow through one of the precleaners to tune the precleaner system to the desired airflow.

A system and method of integrating an engine having dynamic skip fire control with an exhaust gas recirculation system in a turbocharged internal combustion engine is described. An engine control system determines an appropriate firing pattern based at least in part on a desired exhaust gas recirculation flow rate. Signals from sensors in the intake manifold and exhaust system may also be used as part of a feedback loop to determine a desired exhaust gas recirculation flow rate.

According to the conventional knowledge, a thermal humidity measurement device has problems in which the direction of air flow is limited to one direction is too hard to handle in securing the humidity responsiveness because there are limitations on the mounting direction of the thermal humidity measurement device and the state of air flow.

An introduction guide protrudes from an air introduction surface to the outside of a measurement chamber, is parallel to a humidity introduction port surface, and has a portion not in contact with an inlet surface of a humidity introduction tube as seen from any direction to guide the flow of air to the humidity introduction tube from any direction of 360°.

Embodiments for controlling condensate in a charge air cooler are provided. In one example, a charge air cooler comprises an inlet to admit charge air, a plurality of heat exchange passages to remove heat from the charge air, an outlet configured to discharge the charge air from the heat exchange passages to an intake passage upstream of an intake manifold of an engine, and a dispersion element extending at least partially across the outlet.