Westport Research Inc.

Westport Power Inc.

Process Systems International, Inc.

Process System International, Inc.

Anker Gram

Mihai Ursan

Stephen Duncan Noble

Sandeep Munshi

John W Bonn

Randall T Mark

Ian Lockley

Gabriel Gavril

Shahin Hessami

Reduced emissions of nitrogen oxides can be achieved if engines are fuelled with mixtures of gaseous fuels such as hydrogen and natural gas. Storing the gaseous fuels separately is desirable so that the fuel mixture ratio can be changed responsive to engine operating conditions. The present apparatus increases the storage density of gaseous fuels such as hydrogen by storing them in gaseous form at high pressures and at sub-ambient temperatures. A first thermally insulated space for holding a first gaseous fuel in a liquefied form is separated from a second thermally insulated space for holding a second gaseous fuel by a thermally conductive fluid barrier. The second gaseous fuel liquefies at a lower temperature than the first gaseous fuel such that the second gaseous fuel can be stored within the second thermally insulated space in a gaseous form at a sub-ambient temperature.

Multi-fuel storage system and method of storing fuel in a multi-fuel storage system

A method is provided for compressing a gas in a single cycle and in a single cylinder to a pressure of at least 17.2 Mpa with a compression ratio of at least about five to one. The method further comprises dissipating heat from the cylinder during the compression stroke whereby the gas is discharged with a temperature significantly less than isentropic. The apparatus comprises a hollow cylinder and a reciprocable free-floating piston disposed therein. The piston divides the cylinder into: (a) a compression chamber within which a gas can be introduced, compressed, and discharged; and, (b) a drive chamber, into which a hydraulic fluid can be introduced and removed for actuating the piston. The apparatus further comprises a piston stroke length to piston diameter ratio of at least seven to one. For operating the apparatus with a compression ratio of at least five to one, an outlet pressure of at least 17.2 Mpa, and a gas discharge temperature significantly less than isentropic, the apparatus can further comprise a variable displacement hydraulic pump for controlling piston velocity, an electronic controller for maintaining an average piston velocity that is less than 0.5 feet per second, and a heat dissipator for dissipating heat from the cylinder.

Method and apparatus for compressing a gas to a high pressure

A re-fueling station is provided for selectively dispensing fuel in the form of liquefied gas or compressed gas. The re-fueling station comprises a storage tank for storing liquefied gas; a positive displacement fuel pump operable to draw fuel from the storage tank and discharge fuel to a flow diverter, which is operable to selectively direct fuel through one of a first outlet or a second outlet; and conduits through which fuel may flow from the first outlet to a heat exchanger and then to a first dispenser for dispensing compressed gas, or from the second outlet to a second dispenser for dispensing liquefied gas. A method is provided comprising operating the fuel pump in a low speed mode when fuel is directed to the first dispenser and operating the fuel pump in a high speed mode when fuel is directed to the second dispenser.

Combined liquefied gas and compressed gas re-fueling station and method of operating same

A reciprocable piston comprises a cylindrical body reciprocable within a hollow cylinder and at least two spaced ring seals disposed around the circumference of the cylindrical body. Within the cylindrical body there is a scavenging system that comprises: an internal chamber that is in fluid communication with a space between the spaced ring seals; and a one-way fluid passage that allows one-way fluid flow from the internal chamber to the cylinder chamber when fluid pressure within the internal chamber is greater than fluid pressure within the cylinder chamber. A method of scavenging fluid comprises collecting fluid that leaks by a piston seal and returning the collected fluid to the cylinder chamber from which it originated, through a scavenging system disposed within the piston.

Reciprocable piston with a fluid scavenging system and method of scavenging a fluid

A medium and high pressure pump systems supplies a cryogenic fluid from a storage tank. The system comprises a pump that is operable to pump cryogenic liquid or a mixture of cryogenic liquid and vapor. The pump preferably comprises an inducer with at least two chambers and means for recycling excess fluid within the inducer instead of returning excess fluid to the storage tank. The reciprocating pump is preferably double acting such that fluid is discharged from the pump during both extension and retraction strokes.

High pressure pump system for supplying a cryogenic fluid from a storage tank

A method and apparatus is provided for supplying both cryogenic liquid and vapor from a storage tank to a pump to reduce the need for venting. The pump is operable to pump cryogenic liquid or a mixture of liquid and vapor. Different operating modes are selectable to control mass flow rate through the pump. With one operating mode a high flow rate is achieved by supplying only cryogenic liquid to the pump. By selecting another operating mode, a lower mass flow rate is achieved by simultaneously supplying liquid and vapor from the storage tank to the pump. The pump preferably has an inducer with at least two chambers and valves for recycling excess fluid within the inducer instead of returning it to the storage tank. The reciprocating pump is preferably double acting such that fluid is discharged from the pump during both extension and retraction strokes.

In the present method and apparatus, cryogenic liquid and vapor are pumped from a storage tank and the proportion of liquid and vapor is controlled so as to influence flow rate through the apparatus. In an induction stroke, the piston of a reciprocating pump is retracted and cryogenic fluid is drawn from the storage tank into a piston chamber associated with the piston. Flow rate is controlled through the apparatus by controlling the proportion of liquid and vapor supplied to the pump during the induction stroke by supplying substantially only vapor to the pump during a portion of the induction stroke. In a compression stroke, the pump compresses and condenses vapor into liquid and then compresses any liquid within the piston chamber; compressed cryogenic fluid is ultimately discharged from the pump. The apparatus preferably includes a pump with a liquid supply line connecting a pump inlet to a storage tank, a vapor supply line connecting an ullage space with a pump inlet, an automatically actuated valve that opens and closes to control the flow of vapor to the pump inlet, and a controller that controls the valve to achieve a desired flow rate.

Method and apparatus for pumping a cryogenic fluid from a storage tank

A double-acting reciprocating motor with uni-directional fluid flow path comprises a piston disposed within a cylinder. A first chamber is defined by the cylinder space between the piston and a cylinder base. A second chamber is defined by the cylinder space between the piston and a cylinder head. Fluid is introduced into the motor through an inlet port and into the first chamber. A pass-through valve controls the flow of fluid from the first chamber to the second chamber. An outlet valve regulates the draining of fluid from the second chamber through an outlet port. The outlet port and the inlet port are associated with opposite ends of the motor. Differential fluid pressure urges the piston towards the cylinder head when the pass-through valve is closed and the outlet valve is open. The piston surface facing the second chamber is larger than the piston surface facing the first chamber, so the piston moves towards the cylinder base when the pass-through valve is open and the outlet valve is closed.

Reciprocating motor with uni-directional fluid flow

This invention relates to a medium and high pressure liquid natural gas fuel system for internal combustion engines and for other cryogenic systems. A cryogenic pump comprising: (a) a vessel for containing compressed gas and liquid; (b) a first chamber in said vessel with an inlet therein for receiving gas and liquid; (c) a second chamber communicating with said first chamber for receiving and dispelling gas and liquid; (d) a third chamber communicating with said second chamber for receiving and dispelling gas and liquid; (e) a reciprocating means separating said first, second and third chambers from one another and for drawing and compressing gas and liquid in any one of the first, second and third chambers; (f) one-way inlet means for enabling gas and liquid to pass into the first chamber; (g) one-way means between said first and second chambers for enabling gas and liquid to pass from said first chamber to said second chamber; (h) one-way means for enabling gas and liquid to return from the second chamber to the first chamber; (i) one-way means between said second and third chambers for enabling gas and liquid to be passed from said second chamber to said third chamber; and (j) one-way means for enabling gas and liquid to be expelled from said third chamber to the exterior of the vessel. The invention also relates to a single action suction and double action discharge pump which can be readily removed from a confined space.

High pressure fuel supply system for natural gas vehicles

The invention relates to an apparatus and method for supplying high pressure gaseous fuel from a storage vessel to an internal combustion engine of a vehicle, or for other uses. A reverse cascade fuel supply apparatus for a vehicle comprising: (a) a storage tank for storing high pressure gaseous fuel; (b) an intermediate pressure accumulator for storing high pressure gaseous fuel, connected by a pipe to the storage tank; (c) a high pressure accumulator for storing high pressure gaseous fuel connected by a pipe to the intermediate accumulator and by a pipe to the storage tank; (d) a gaseous fuel compressing intensifier connected by a pipe to the storage tank, the intermediate pressure accumulator and the high pressure accumulator; and (e) a plurality of on-off pressure controlled valves located in the pipes connecting the storage tank, the intermediate accumulator, the high pressure accumulator and the intensifier, for enabling selective pumping to and withdrawal of high pressure gaseous fuel from the storage tank, the intermediate accumulator, the high pressure accumulator, the intensifier or the engine, according to a reverse cascade fuel supply program.

Compressed natural gas cylinder pump and reverse cascade fuel supply

A system and method for the delivery of cryogenic fluid, more particularly a cryogenic fuel, such as, for example, but not limited to an liquified natural gas (LNG), to a cryogenic fluid using source, and more particularly an LNG fuel source, and even more particularly an LNG fuel-operated engine. The system includes a source of a cryogenic fluid, more particularly an underground tank and with a liquid level within the underground tank source. The system includes a delivery pump to deliver cryogenic fluid from the underground tank source, to a cryogenic using source, typically an LNG fuel source above the underground tank source, with the pump located below the liquid level of the cryogenic fluid in the cryogenic fluid fuel tank. The system includes a sump containing cryogenic fluid, and the delivery pump positioned and immersed in the cryogenic liquid in the sump, and a conduit and valve to deliver cryogenic fluid through the use of the cryogenic fluid flow pump from the underground cryogenic fluid tank source to an above-ground or level using source, such as an LNG operated vehicle.

Cryogenic fluid system and method of pumping cryogenic fluid

Cryogenic fluid piston pump functions as stationary dispensing pump, mobile vehicle fuel pump etc., and can pump vapour and liquid efficiently even at negative feed pressures, thus permitting pump location outside a liquid container. Piston inducts fluid by removing vapour from liquid in an inlet conduit faster than the liquid therein can vaporize by absorbing heat, and moves at essentially constant velocity throughout an induction stroke to generate an essentially steady state induction flow with negligible restriction of flow through an inlet port. Stroke displacement volume is at least two orders of magnitude greater than residual or dead volume remaining in cylinder during stroke changeover, and is greater than volume of inlet conduit. Cryogenic tank has a liquid compartment, a vapour compartment, and inlet and overflow conduits. Inlet conduit receives liquid from dispensing pump and widely disperses liquid into liquid tank to contact and condense vapour. Overflow conduit restricts flow of excess liquid from liquid compartment to vapour compartment. Excess pressure in tank or temperature of overflow liquid from conduit is detected to automatically stop dispensing pump. As a fuel pump, the pump selectively receives cryogenic liquid and vapour from respective conduits communicating with tank, and pumps cryogenic liquid to satisfy relatively heavy fuel demand of engine, which, when satisfied, also pumps vapour to reduce vapour pressure in the tank while sometimes satisfying relatively lighter fuel demand.

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Vancouver, Canada

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