摘要:
A thermal sub-system for a fuel cell system that uses pump characteristics to determine a required cooling fluid volume flow. An algorithm controls the speed of the pump to provide the desired volume flow of the cooling fluid for the system parameters. The algorithm determines a motor efficiency value based on a pump input power value and a pump speed value. The algorithm then determines a coefficient of power value based on the motor efficiency value, the pump input power value and the pump speed value. The algorithm then uses a look-up table to convert the coefficient of power value to a coefficient of flow value. The algorithm then calculates the volume flow based on the coefficient of flow value and the pump speed value.
摘要:
A thermal sub-system for a fuel cell system that employs an algorithm using feed-forward control. The algorithm calculates a Reynolds number based on the velocity of the cooling fluid, a diameter of a coolant loop pipe and a kinematic viscosity (temperature) of a cooling fluid. The algorithm also uses a pressure loss number based on the Reynolds number and a position of a by-pass valve. The algorithm also defines a pressure loss value based on the pressure loss number, the density of the cooling fluid and the velocity of the cooling fluid. The algorithm then calculates a delivery head value based on the pressure loss value, the fluid density and a gravitational acceleration. The algorithm then uses the delivery head value and a predetermined set-point value of the volume flow to determine a desired pump speed based on the current operating parameters of the system.
摘要:
A method and system for controlling a pressure regulator in a gas storage system using a pressure switch as a pressure measurement device. A controller uses supply pressure data and gas flow demand data to compute a feed-forward control term, and uses data from a pressure sensor downstream of the pressure regulator to compute a feedback control term. During normal operation, with pressure downstream of the regulator oscillating about a set point pressure, on-time and off-time periods of a pressure switch are monitored, and an adaptive control term is computed which balances on-time and off-time. If the pressure sensor fails, excessive switch on-time or off-time will be detected; in response to this, the feedback control term is disregarded, and an adaptive control term is computed which aims to restore balanced on-time and off-time of the switch, thus indicating that the actual pressure is oscillating about the set point.
摘要:
A thermal sub-system for a fuel cell system that employs an algorithm using feed-forward control. The algorithm calculates a Reynolds number based on the velocity of the cooling fluid, a diameter of a coolant loop pipe and a kinematic viscosity (temperature) of a cooling fluid. The algorithm also uses a pressure loss number based on the Reynolds number and a position of a by-pass valve. The algorithm also defines a pressure loss value based on the pressure loss number, the density of the cooling fluid and the velocity of the cooling fluid. The algorithm then calculates a delivery head value based on the pressure loss value, the fluid density and a gravitational acceleration. The algorithm then uses the delivery head value and a predetermined set-point value of the volume flow to determine a desired pump speed based on the current operating parameters of the system.
摘要:
A method and system for controlling a pressure regulator in a gas storage system using a pressure switch as a pressure measurement device. A controller uses supply pressure data and gas flow demand data to compute a feed-forward control term, and uses data from a pressure sensor downstream of the pressure regulator to compute a feedback control term. During normal operation, with pressure downstream of the regulator oscillating about a set point pressure, on-time and off-time periods of a pressure switch are monitored, and an adaptive control term is computed which balances on-time and off-time. If the pressure sensor fails, excessive switch on-time or off-time will be detected; in response to this, the feedback control term is disregarded, and an adaptive control term is computed which aims to restore balanced on-time and off-time of the switch, thus indicating that the actual pressure is oscillating about the set point.
摘要:
A thermal sub-system for a fuel cell system that calculates a desired volume flow or mass flow of a cooling fluid pumped through a fuel cell stack solely on thermal stack power loss and cooling fluid temperature. An algorithm calculates a power loss of the stack and then calculates the temperature of the stack based on the power loss and dissipated heat power from the stack. The algorithm uses the temperature of the stack and the temperature of the cooling fluid out of the stack to determine the dissipated heat power. The algorithm then uses the temperature of the stack, the temperature of the cooling fluid into the stack and the temperature of the cooling fluid out of the stack to determine the flow.
摘要:
High pressure gas vessels can have a sensitivity to temperature of the compressed gas. Over-temperature conditions in particular may cause decreased durability and/or vessel damage, including gas leakage to the environment. Articles of manufacture, methods, and systems are provided for over-temperature protection using a passive device. The passive closing device does not require electrical power and no controller, sensors, or wiring is needed. This affords cost savings in comparison to other systems. Pressure vessels using the passive closing device can protect themselves, independent of the compressed gas fueling station configuration.
摘要:
A system and method for determining whether a shut-off valve in a cabin heating by-pass line of a thermal sub-system associated with an engine has failed that uses the pump current for a pump that pumps the cooling fluid through the by-pass line. The method includes setting a predetermined constant speed of the pump and then providing a valve command that opens the by-pass valve. The method then determines if the pump current has increased or remained substantially the same when the by-pass valve is commanded open, and determines that the by-pass valve has not opened if the pump current remains substantially constant when the by-pass valve is commanded open.
摘要:
A communication interface for communication between a storage tank and a refueling station is described. One embodiment of the communication interface includes a control unit; an optical transmitter comprising an IR-LED, the optical transmitter directly integrated into the control unit or mounted on the control unit; and an optical frontend optically connected to the optical transmitter.
摘要:
An angle sensor includes two measuring pinions which rotate in the same direction in response to a drive pinion rotating. The measuring pinions have different absolute angular positions after rotating. The absolute angular position of the drive pinion is determinable from the absolute angular positions of the measuring pinions. A delta wheel between the measuring pinions has two coaxially arranged rings. One ring engages the second measuring pinion and the other ring engages the first measuring pinion such that the rings rotate relative to one another in the same direction in response to the measuring pinions rotating in the opposite direction. A spring connecting the rings together biases the rings to move in opposite directions toward one another after the rings have been rotated relative to one another in the same direction such that the rings respectively press the measuring pinions against the drive pinion.