Cooling device (15) for cooling semiconductor switching elements (10, 11), comprising a first wall (17) having a first side (18) for carrying the semiconductor switching elements (10, 11) and having a second side (19) being opposite the first side (18), a second wall (20) having a first side (21) that forms a main cooling channel (22) together with the second side (19) of the first wall (17) and having a second side (25) being opposite to the first side (21) of the second wall (20), and a third wall (23) that forms an auxiliary cooling channel (24) together with the second side (25) of the second wall (20), wherein the second wall (20) comprises a connection means (26) that connects the auxiliary cooling channel (24) with the main cooling channel (22) in a fluid-conductive manner.

A constant density heat exchanger and system for energy conversion is provided. The constant density heat exchanger includes a housing extending between a first end and a second end and defining a chamber having an inlet and an outlet. A first flow control device is positioned at the inlet of the chamber and movable between an open position in which a working fluid is permitted into the chamber and a closed position in which the working fluid is prevented from entering the chamber. A second flow control device is positioned at the outlet of the chamber and movable between an open position in which the working fluid is permitted to exit the chamber and a closed position in which the working fluid is prevented from exiting the chamber. A heat exchange fluid imparts thermal energy to the volume of working fluid as the first flow control device and the second flow control device hold the volume of working fluid at constant density within the chamber.

A flexible sealing tube is described that is adapted to be installed in and extend along a bore in the ground for use in a system for exchanging of energy with the ground. The flexible sealing tube has a first tube end to be installed at an inner part of said bore, and the flexible sealing tube is closed in the first tube end. The flexible sealing tube also has a first channel and a second channel extending in a longitudinal direction (L) of the flexible sealing tube, the first and second channels being in fluid connection with each other. The first and second channels are formed by the flexible sealing tube.

There is disclosed a heat exchanger comprising a first channel, for communicating between a first channel inlet and a first channel outlet, a second channel for communicating between a second channel inlet and a second channel outlet, a third channel for communicating between a third channel inlet and a third channel outlet, a first conduit interconnecting the first channel and the third channel, and thereby defining a first group of interconnected channels, the first conduit extending through the second channel.

There is disclosed a heat exchanger comprising: a plurality of first fluid channels, a plurality of conduits for interconnecting the first fluid channels, a plurality of second fluid channels, a plurality of conduits for interconnecting the second fluid channels, wherein the heat exchanger is configured as a plurality of repeating units, each repeating unit comprising: a base plate comprising a first opening, and a first conduit extending from the plate, the shape of the opening corresponding to the shape of the conduit.

A constant density heat exchanger is provided. The constant density heat exchanger includes a housing extending between a first end and a second end and defining a chamber having an inlet and an outlet. A first flow control device is positioned at the inlet of the chamber and movable between an open position in which a working fluid is permitted into the chamber and a closed position in which the working fluid is prevented from entering the chamber. A second flow control device is positioned at the outlet of the chamber and movable between an open position in which the working fluid is permitted to exit the chamber and a closed position in which the working fluid is prevented from exiting the chamber. A heat exchange fluid imparts thermal energy to the volume of working fluid held at constant density within the chamber by the first and second control devices.

An energy conversion apparatus may include an engine assembly, such as a monolithic engine assembly. The engine assembly may include a first monolithic body segment and a plurality of second monolithic body segments directly coupled or directly couplable to the first monolithic body segment. The first monolithic body segment may define a combustion chamber and a recirculation pathway in fluid communication with the combustion chamber. The recirculation pathway may be configured to recirculate combustion gas through the combustion chamber. The plurality of second monolithic body segments may respectively define at least a portion of a piston chamber and a plurality of working-fluid pathways fluidly communicating with the piston chamber.

A heat exchanger includes a body, a plurality of first flow channels defined in the body, and a plurality of second flow channels defined in the body. The second flow channels are fluidly isolated from the first flow channels. At least two of the second flow channels are adjacent each other and are separated from each other by at least one common fin, wherein the at least one common fin includes an opening defined therein for permitting flow between the adjacent second flow channels.

An engine body may include a piston body comprising a piston chamber and a regenerator body comprising a regenerator conduit. An engine body may include a working-fluid heat exchanger body comprising a plurality of working-fluid pathways fluidly communicating between the piston chamber and the regenerator conduit. Additionally, or alternatively, an engine body may include a heater body comprising a plurality of heating fluid pathways and the plurality of working-fluid pathways. The heating fluid pathways may have a heat transfer relationship with the working fluid pathways. The working-fluid pathways may fluidly communicate between the piston chamber and the regenerator conduit. The engine body may include a monolithic body defined at least in part by the piston body, the regenerator body, and the working-fluid heat exchanger body, and/or defined at least in part by the piston body, the regenerator body, and the heater body.

A heating apparatus comprising a tank having a tank inlet, a tank outlet, a heat exchanger inlet and heat exchanger outlet. A heat exchanger is located in the tank and comprises a hollow body having a mouth coupled to the heat exchanger inlet and a flue outlet coupled to the heat exchanger outlet. A burner device has a burner head that is located at least partly located in the mouth inside said hollow body.