A three-dimensional pulsating heat pipe includes a pipe member and a connecting member. The pipe member is coiled around an axis to form a plurality of loop portions, and the loop portions are arranged in order along the axis so as to form a three-dimensional coiled structure. The three-dimensional coiled structure has a heat receiving section, and the pipe member has different effective pipe cross-sectional areas on two opposite sides adjacent to the heat receiving section. The connecting member is connected to two ends of the pipe member, such that the connecting member and the pipe member together form a closed loop.

A method to improve thermal performance of vascular composites by using a two-phase working fluid for isothermalization includes the steps of: manufacturing a vascular composite structure optimized for a design point; manufacturing a thermal back end sized for the application; integrating the vascular composite into a fluid loop; and evacuating and filling the fluid loop with working fluid to an amount resulting in two-phase operation at the design point.

A three-dimensional pulsating heat pipe includes a pipe member and a connecting member. The pipe member is coiled around an axis to form a plurality of circular pipe portions, and the circular pipe portions are arranged in order along the axis so as to form a three-dimensional coiled structure. The three-dimensional coiled structure has a heat receiving section, and the pipe member has different effective pipe cross-sectional areas on two opposite sides adjacent to the heat receiving section. The connecting member is connected to two ends of the pipe member, such that the connecting member and the pipe member together form a closed loop.

A pump assisted heat pipe may combine the low mass flow rate required of latent heat pipe transfer loops with a hermetically sealed pump to overcome the typical heat pipe capillary limit. This may result in a device with substantially higher heat transfer capacity over conventional pumped single-phase loops, heat pipes, loop heat pipes, and capillary pumped loops with very modest power requirements to operate. Further, one or more embodiments overcome the gravitation limitations in the conventional heat pipe configuration, e.g., when the heat addition zone is above the heat rejection zone, the capillary forces are required to transfer the liquid from the heat rejection zone to the heat addition zone against gravity.

A water cooling head includes water cooling head includes a casing, a base and a pump. The casing includes an inlet and an outlet. An outer side of the base has a heat-absorbing surface. A thermal conduction structure is disposed on an inner side of the base. An active space is defined by the base and the casing collaboratively. The pump includes a first magnetic element, a second magnetic element, an impeller and a pivotal part. The first magnetic element is located outside the active space. The first magnetic element is arranged between the impeller and the base along a direction perpendicular to the base. The pivotal part, the second magnetic element and the impeller are disposed within the active space. The pivotal part is connected with the impeller and arranged between the impeller and the base. The second magnetic element is installed on the pivotal part.

A cooling device includes a partitioning board abutting inner faces of two boards, respectively. A chamber is defined between the partitioning board and one of the two boards. Another chamber is defined between the partitioning board and another of the two boards and intercommunicates with the chamber via an intercommunication port and a backflow port of the partitioning board. A pump drives a working fluid to circulate in the two chambers. Two welding channels are formed on outer faces of the two boards and surround the two chambers, respectively. The smallest distance between a channel bottom face of each annular welding channel and the inner face of a respective board having the annular welding channel is smaller than that between the inner and outer faces of the respective board. The two boards are coupled to the partitioning board along the annular welding channels by laser welding.

The invention relates to a bypass valve (1), having a valve housing (4) and a slide (3) arranged for longitudinal movement in the valve housing (4). An inlet channel (5), an outlet channel (6), and a further outlet channel (7) are formed in the valve housing (4). The slide (3) interacts with a valve seat (8) formed in the valve housing (4) by means of the longitudinal movement of the slide and thereby opens and closes a hydraulic connection between the inlet channel (5) and the outlet channel (6). Furthermore, the slide (3) interacts with a further valve seat (8b) formed in the valve housing (4) by means of the longitudinal movement of the slide and thereby opens and closes a further hydraulic connection between the inlet channel (5) and the further outlet channel (7). A control surface (3c) is formed on the slide (3), wherein the control surface (3c) delimits a control chamber (34). The pressure in the control chamber can be hydraulically controlled by means of a pilot valve (2).

An improved heat engine includes at least one heat pipe containing a working fluid flowing in a thermal cycle between vapor phase at an evaporator end and liquid phase at a condenser end. The heat pipe may have an improved capillary structure configuration with a continuous or stepwise gradient in pore size along the capillary flow direction. The heat engine may have an improved generator assembly configuration that includes an expander (e.g. rotary/turbine or reciprocating piston machine) and generator along with magnetic bearings, magnetic couplings, and/or magnetic gearing. The expander-generator may be wholly or partially sealed within the heat pipe. A heat engine system (e.g. individual heat engine or array of heat engines in series and/or in parallel) for converting thermal energy to useful work (including heat engines operating from a common heat source) is also disclosed. The system can be installed in a vehicle or facility to generate electricity.

The present invention includes a heat exchanger reactive to external and internal temperatures for carrying a working fluid, including two pairs of nested pipes; each pair including one pipe with a channel portion and a stress relief portion and a second pipe with just a channel portion, one of said pipes enclosing the other with an interference fit and both pipes having different coefficients of thermal expansion. The first pair of pipes positioned co-axially with and encompassing the second pair. A fluid is positioned in the space defined by the inner surface of outer pair of pipes and the outer surface of inner pair of pipes. The two pipe pairs have positions responsive to the internal and external temperatures in which the space defined by pipe pairs is either minimized or maximized by expansion and contraction of the pipe pairs caused by differences in coefficients of thermal expansion.

An evaporator device is provided, including a chamber including an inlet, an outlet, and a surface, the inlet being configured to direct a liquid coolant into the chamber and the outlet is configured to direct a vapor coolant away from the chamber, and the surface is in thermal communication with the liquid coolant or the vapor coolant, and a porous unit disposed adjacent to the surface, the porous unit being configured to (i) absorb the liquid coolant, (ii) bring the liquid coolant into thermal communication with the surface, (iii) subject the liquid coolant to a phase transition to a vapor coolant, and (iv) direct said vapor coolant away from the surface, wherein the surface and the porous unit are of different materials, and the porous unit is thermally insulating.