A device including a liquid's flow path having an upstream side and a downstream side, a plurality of flow restrictive elements providing material communication between the upstream side to the downstream side, a thermoelectric generator or a thermophotovoltaic cell in thermal connection with a portion of the device located at the downstream side with respect to the plurality of flow restrictive elements. The portion is provided with roughness elements for, in use, contacting a fluid flowing through the device and facilitating collapse of cavitation bubbles.

A device including a liquid's flow path having an upstream side and a downstream side, a plurality of flow restrictive elements providing material communication between the upstream side to the downstream side, a thermoelectric generator or a thermophotovoltaic cell in thermal connection with a portion of the device located at the downstream side with respect to the plurality of flow restrictive elements. The portion is provided with roughness elements for, in use, contacting a fluid flowing through the device and facilitating collapse of cavitation bubbles.

An apparatus is provided having a heat generation device such as a boiler. A hypersonic energy harvester is provided having a first input and a second input. The first input and the second input are fluidly coupled to the heat generation device. A variable speed pump is fluidly coupled to supply liquid from the heat generation device to the hypersonic energy harvester. A deaerator is fluidly coupled to receive condensate from the hypersonic energy harvester.

A mobile heating system includes an enclosure defining a plenum that houses a fan and an internal combustion engine. The heating system also includes a hydraulic circuit including a hydraulic pump operably coupled to the internal combustion engine and a first heat exchanger located in the plenum and in fluid communication with the hydraulic pump. The hydraulic circuit also includes a hydraulic motor operably coupled to the fan wherein the hydraulic motor is in fluid communication with and driven by the hydraulic pump. A first valve is disposed between the hydraulic pump and the heat exchanger and is configured to restrict fluid flow and to increase a fluid pumping pressure of the hydraulic pump. A second valve is located upstream of the first valve and is configured to selectively direct hydraulic fluid between the first valve and the hydraulic motor.

A device including a liquid's flow path having an upstream side and a downstream side, a plurality of flow restrictive elements providing material communication between the upstream side to the downstream side, a thermoelectric generator or a thermophotovoltaic cell in thermal connection with a portion of the device located at the downstream side with respect to the plurality of flow restrictive elements. The portion is provided with roughness elements for, in use, contacting a fluid flowing through the device and facilitating collapse of cavitation bubbles.

A device including a liquid's flow path having an upstream side and a downstream side, a plurality of flow restrictive elements providing material communication between the upstream side to the downstream side, a thermoelectric generator or a thermophotovoltaic cell in thermal connection with a portion of the device located at the downstream side with respect to the plurality of flow restrictive elements. The portion is provided with roughness elements for, in use, contacting a fluid flowing through the device and facilitating collapse of cavitation bubbles.

A mobile heating system is disclosed. In one embodiment, the system includes an enclosure defining a plenum that houses a fan and an internal combustion engine. The heating system also includes a hydraulic circuit including a hydraulic pump operably coupled to the internal combustion engine and a first heat exchanger located in the plenum and in fluid communication with the hydraulic pump. The hydraulic circuit also includes a hydraulic motor operably coupled to the fan wherein the hydraulic motor is in fluid communication with and driven by the hydraulic pump. A first valve is disposed between the hydraulic pump and the heat exchanger and is configured to restrict fluid flow and to increase a fluid pumping pressure of the hydraulic pump. A second valve is located upstream of the first valve and is configured to selectively direct hydraulic fluid between the first valve and the hydraulic motor.

A hot water pressure washer employs a high-pressure pump for generating a stream of high pressure fluid and a hydrodynamic heater operable for heating the fluid stream. The hydrodynamic heater includes an inlet port fluidly connectable to a fluid source and an outlet port fluidly connected to an inlet port of the high-pressure washer. An outlet port of the high-pressure washer is connectable to a handheld wand operable for discharging the fluid stream to atmosphere. A prime-mover provides rotational torque for driving the hydrodynamic heater and the high-pressure pump. An unloader valve is used to control distribution of the fluid stream discharged from the high-pressure pump. An exhaust gas recovery heat exchanger operates to transfer heat from the prime-mover exhaust gas to the fluid stream. A pre-heat tank is used to temporarily store a quantity of heated fluid for future use.

A transonic two-phase reaction turbine for use with low and high temperature fluid flow mediums includes at least two wheels that are configured to rotate in opposite directions, at least one of the at least two wheels being equipped with one or multiple kinetic energy harvesters.

A flameless heater includes a diesel engine, a hydraulic or electric load that is powered by the diesel engine thereby generating heat, a heat exchanger that transfers heat to air flowing through the air from the flameless heat source, and possibly other heat exchangers for heating the air flowing therethrough with engine coolant and/or with exhaust gases. The system may be operated to maintain relatively high load on the engine for at least the majority of the time so as to reduce or negate the need for parked regeneration. The system may also control airflow through the system and possibly other system parameters to obtain a given setpoint such as a given discharge air temperature. In one embodiment, airflow through the system is controlled by louvers under the power of an electric motor or other actuator controlled by the system's controller.