Abstract: It is challenging to detect end of stroke for hydraulically actuated, reciprocating piston pumps for a variety of reasons. When the pump pressurizes a process fluid to a 10 relatively low pressure the magnitude of hydraulic fluid pressure is not as distinct compared to the magnitude of a pressure drop across a shuttle valve employed to detect end of stroke, which makes detecting the end of stroke event difficult. A method is disclosed for detecting end of a piston stroke in a hydraulic motor comprising a reciprocating piston with a shuttle valve. The method comprises 1 detecting end of piston stroke when a magnitude of a rate of change of hydraulic fluid pressure is substantially greater than a magnitude of a mean rate of change of hydraulic fluid pressure over said piston stroke; and noise in a hydraulic fluid pressure signal is substantially negligible.

Abstract: A reciprocating piston cryogenic pump has been suspended from stroking when process fluid discharge temperature from a vaporizer dropped below a threshold to prevent freezing of a heat exchange fluid circulating through the vaporizer and damage to downstream components. Suspension of the pump results in a decrease of process fluid pressure downstream of the vaporizer, which is undesirable. In the present technique, a temperature is monitored correlating to process fluid temperature downstream of the vaporizer. The amount of process fluid discharged from the pump in each cycle is adjusted as a function of the temperature such that the average residence time of the process fluid in the vaporizer is increased as the discharge amount decreases, increasing process fluid discharge temperature. The average mass flow rate of the process fluid through the vaporizer is unchanged regardless of pump discharge amount such that process fluid pressure downstream of the vaporizer is maintained.

Abstract: The problem arises of how to control a plurality of hydraulic pumps to achieve desired performance criteria, such as reduced wear and/or power consumption. The hydraulic pumps are operated in a hydraulic system for delivering hydraulic fluid to a hydraulic motor in a cryogenic pumping apparatus in an engine system fuelled with a gaseous fuel. A controller is operatively connected with the plurality of hydraulic pumps and is programmed to periodically determine a priority for each hydraulic pump as a function of predetermined criteria such as respective cumulative pumping cycles. Higher priority hydraulic pumps are operated before lower priority hydraulic pumps, that is in descending order of priority, to supply hydraulic fluid to the hydraulic motor. Hydraulic pumps are selected to operate according to the desired performance criteria.

Abstract: A method and system is disclosed for delivering a cryogenically stored fuel in a gaseous state into the air intake system of a gaseous fuelled internal combustion engine. The method comprises determining the flow rate capacity in the engine system's fuel delivery line, comparing the determined flow rate capacity to a required flow rate demand and supplying fuel in gaseous state directly from the vapor space of the cryogenic storage vessel to the fuel delivery line that supplies fuel to the engine, when the flow rate capacity is equal to or higher than the required flow rate demand. The method further comprises activating a cryogenic pump to deliver fuel to the internal combustion engine from the liquid space of the cryogenic storage vessel when the determined flow rate capacity is lower than the required flow rate demand.

Abstract: An apparatus and method estimate fluid mass in a cryogenic tank that holds a multiphase fluid comprising a liquid and a vapor. The apparatus comprises a level sensor, a pressure sensor and a computer. The level sensor provides a parameter representative of a level of the liquid. The pressure sensor provides a pressure signal representative of vapor pressure inside the cryogenic tank. The computer is operatively connected with the level sensor and the pressure sensor to receive the parameter and the pressure signal, and is programmed to determine the level from inputs comprising the parameter, to calculate a first volume of the liquid from inputs comprising the level, and to calculate a first mass of the liquid from inputs comprising the first volume and the pressure signal.

Abstract: It is challenging to detect end of stroke for hydraulically actuated, reciprocating piston pumps for a variety of reasons. When the pump pressurizes a process fluid to a 10 relatively low pressure the magnitude of hydraulic fluid pressure is not as distinct compared to the magnitude of a pressure drop across a shuttle valve employed to detect end of stroke, which makes detecting the end of stroke event difficult. A method is disclosed for detecting end of a piston stroke in a hydraulic motor comprising a reciprocating piston with a shuttle valve. The method comprises 1 detecting end of piston stroke when a magnitude of a rate of change of hydraulic fluid pressure is substantially greater than a magnitude of a mean rate of change of hydraulic fluid pressure over said piston stroke; and noise in a hydraulic fluid pressure signal is substantially negligible.

Abstract: A method and system is disclosed for delivering a cryogenically stored fuel in a gaseous state into the air intake system of a gaseous fuelled internal combustion engine. The method comprises determining the flow rate capacity in the engine system's fuel delivery line, comparing the determined flow rate capacity to a required flow rate demand and supplying fuel in gaseous state directly from the vapor space of the cryogenic storage vessel to the fuel delivery line that supplies fuel to the engine, when the flow rate capacity is equal to or higher than the required flow rate demand. The method further comprises activating a cryogenic pump to deliver fuel to the internal combustion engine from the liquid space of the cryogenic storage vessel when the determined flow rate capacity is lower than the required flow rate demand.

Abstract: The problem arises of how to control a plurality of hydraulic pumps to achieve desired performance criteria, such as reduced wear and/or power consumption. The hydraulic pumps are operated in a hydraulic system for delivering hydraulic fluid to a hydraulic motor in a cryogenic pumping apparatus in an engine system fuelled with a gaseous fuel. A controller is operatively connected with the plurality of hydraulic pumps and is programmed to periodically determine a priority for each hydraulic pump as a function of predetermined criteria such as respective cumulative pumping cycles. Higher priority hydraulic pumps are operated before lower priority hydraulic pumps, that is in descending order of priority, to supply hydraulic fluid to the hydraulic motor. Hydraulic pumps are selected to operate according to the desired performance criteria.

Abstract: A module for managing mass flow and dampening pressure pulsations in the supply line of a gaseous fuelled internal combustion engine comprises a hollow body defining an expanded volume that is fluidly connected directly to a pressure sensor and a temperature sensor. The module is placed along the supply line of a gaseous fuel engine between a fuel pressure increasing device and the fuel rail that supplies fuel to the engine. The module can comprise a filter that filters the impurities from the gaseous fuel supplied to the engine and an overpressure protection device that can vent some of the gaseous fuel from the module to protect it from over-pressurization.

Abstract: An apparatus and method estimate fluid mass in a cryogenic tank that holds a multiphase fluid comprising a liquid and a vapor. The apparatus comprises a level sensor, a pressure sensor and a computer. The level sensor provides a parameter representative of a level of the liquid. The pressure sensor provides a pressure signal representative of vapor pressure inside the cryogenic tank. The computer is operatively connected with the level sensor and the pressure sensor to receive the parameter and the pressure signal, and is programmed to determine the level from inputs comprising the parameter, to calculate a first volume of the liquid from inputs comprising the level, and to calculate a first mass of the liquid from inputs comprising the first volume and the pressure signal.

Abstract: A reciprocating piston cryogenic pump has been suspended from stroking when process fluid discharge temperature from a vaporizer dropped below a threshold to prevent freezing of a heat exchange fluid circulating through the vaporizer and damage to downstream components. Suspension of the pump results in a decrease of process fluid pressure downstream of the vaporizer, which is undesirable. In the present technique, a temperature is monitored correlating to process fluid temperature downstream of the vaporizer. The amount of process fluid discharged from the pump in each cycle is adjusted as a function of the temperature such that the average residence time of the process fluid in the vaporizer is increased as the discharge amount decreases, increasing process fluid discharge temperature. The average mass flow rate of the process fluid through the vaporizer is unchanged regardless of pump discharge amount such that process fluid pressure downstream of the vaporizer is maintained.

Abstract: A module for managing mass flow and dampening pressure pulsations in the supply line of a gaseous fuelled internal combustion engine comprises a hollow body defining an expanded volume that is fluidly connected directly to a pressure sensor and a temperature sensor. The module is placed along the supply line of a gaseous fuel engine between a fuel pressure increasing device and the fuel rail that supplies fuel to the engine. The module can comprise a filter that filters the impurities from the gaseous fuel supplied to the engine and an overpressure protection device that can vent some of the gaseous fuel from the module to protect it from over-pressurization.

Abstract: An apparatus and method estimate fluid mass in a cryogenic tank that holds a multiphase fluid comprising a liquid and a vapor. The apparatus comprises a level sensor, a pressure sensor and a computer. The level sensor provides a parameter representative of a level of the liquid. The pressure sensor provides a pressure signal representative of vapor pressure inside the cryogenic tank. The computer is operatively connected with the level sensor and the pressure sensor to receive the parameter and the pressure signal, and is programmed to determine the level from inputs comprising the parameter, to calculate a first volume of the liquid from inputs comprising the level, and to calculate a first mass of the liquid from inputs comprising the first volume and the pressure signal.