A counterflow heat transfer system comprises a heat exchanger and a flow controller arranged to convey a first fluid through the heat exchanger in a first flow direction and a second fluid through the heat exchanger in a second counterflow direction. The heat exchanger comprises at least one first thermally conductive tube conveying the first fluid and at least one second thermally conductive tube conveying the second fluid. The first and second tubes are wound around one another and in contact with one another in an entwined tubular arrangement.

Systems and methods described herein are directed to rotary heat exchangers configured to transfer heat to a heat transfer medium flowing in substantially axial direction within the heat exchangers. Exemplary heat exchangers include a heat conducting structure which is configured to be in thermal contact with a thermal load or a thermal sink, and a heat transfer structure rotatably coupled to the heat conducting structure to form a gap region between the heat conducting structure and the heat transfer structure, the heat transfer structure being configured to rotate during operation of the device and flow a heat transfer medium in a substantially axial direction through the heat transfer structure. In example devices heat may be transferred across the gap region from a heated axial flow of the heat transfer medium to a cool stationary heat conducting structure, or from a heated stationary conducting structure to a cool axial flow of the heat transfer medium.

An apparatus and method of forming a heat exchanger can include a first manifold that defines a first fluid inlet to the heat exchanger and a second manifold that defines a second fluid inlet to the heat exchanger. A lattice cell body can be provided in the heat exchanger that can form a first set of flow passages and a second set of flow passages. The first and second sets of flow passages can be intertwined with one another.

An apparatus and method of forming a heat exchanger can include a first manifold that defines a first fluid inlet to the heat exchanger and a second manifold that defines a second fluid inlet to the heat exchanger. A lattice cell body can be provided in the heat exchanger that can form a first set of flow passages and a second set of flow passages. The first and second sets of flow passages can be intertwined with one another.

A method for forming a crystal nucleus in a latent heat storage material contains a solvent and a dissolved substance. The solvent contains water as the main ingredient. The latent heat storage material retains latent heat in a supercooled state. The method includes: (a) separating out an anhydride of the dissolved substance by heating or cooling part of the latent heat storage material in the supercooled state; and (b) supplying a droplet comprising water to the anhydride, to terminate the supercooled state of the latent heat storage material, and make the latent heat storage material dissipate heat.

The present disclosure discloses a defrosting device, including a heating unit provided in an evaporator; and a heat pipe, both end portions of which are connected to an inlet and an outlet of the heating unit, respectively, and at least part of which is disposed adjacent to a cooling tube to dissipate heat to the cooling tube of the evaporator due to high-temperature working fluid heated and transferred by the heating unit, wherein the heating unit includes a heater case provided with a vacant space therein, and provided with the inlet and the outlet at positions separated from each other, respectively, along a length direction; and a heater attached to an outer surface of the heater case to heat working fluid within the heater case.

Energy storage and retrieval systems are disclosed, along with methods of storing and retrieving the energy. The systems include an energy storage system and a trilateral cycle. The energy storage system includes low- and high-temperature energy storage tanks storing one or more energy storage media that exchange heat with a working fluid in both a gradient heat exchanger and a substantially isothermal heat exchanger in the trilateral cycle. Pressure changing devices transport the energy storage medium/media between the storage tanks and through the heat exchangers. The working fluid rejects heat to the energy storage medium and drives a turbine when the system is charging, and the energy storage medium rejects heat to the working fluid when the system is discharging. In some embodiments, the energy storage medium drives a second turbine when the system is discharging.

A tracer panel that is easily installed on a structure (e.g., process pipe, vessel, or the like) in the proper locations and orientations. The tracer panel may be made of tubes of particular sizes (e.g., lengths, orientation, bend(s), or the like), which may be partially pre-formed and/or partially formed on site (e.g., cut, bent, assembled, or the like on-site) into the tracer panel. The tracers of the tracer panel may be connected by stiffener members to aid in restricting deformation of the panel or may use flexible members to allow installation on different curved surfaces. The tracer panel may be connected with other tracer panels to form a tracer system. Heat transfer elements and/or heat transfer panels (e.g., made up of multiple heat transfer elements) may be assembled to the tracer panel to improve the heat transfer between the tracer panel and the structure.

A method for making a heat exchanger includes providing a first outer tube, and an inner tube disposed in the first outer tube; placing a first coiled heat-transfer tube in a space defined between the inner tube and the first outer tube without being fixed to either one of an outer peripheral surface of the inner tube and an inner peripheral surface of the first outer tube, the first coiled heat-transfer tube including a plurality of coiled sections, an inside space of the heat-transfer tube defining a first flow path, a coiled space defined between coiled sections of the heat-transfer tube in the space, defined between the inner tube and the first outer tube, defining a second flow path, wherein heat is exchanged between two fluids.

A heat exchanger includes a body shaped to integrate with one or more system structural elements and a plurality of first flow channels defined in the body. The heat exchanger also includes a plurality of second flow channels defined in the body. The second flow channels are fluidly isolated from the first flow channels. The first flow channels and the second flow channels have a changing flow direction characteristic along a direction of flow within the first flow channels and the second flow channels.