[Problems to be Solved] An exhaust duct (4) for assembly into a combustion apparatus has: a burner (1) to eject air-fuel mixture downward; and a combustion box (3) disposed on a lower side of the burner (1). The exhaust duct includes: a riser duct section (42) elongated in a vertical direction and having, at a lower portion thereof, an inlet port (41) connected to an exhaust port (35) for combustion gas which is opened in a lower portion of the combustion box (3); and a flat horizontal duct section (43) bent at an upper end of the riser duct section (42) so as to be elongated forward. By restraining the resonance of an upper wall part (431) and a lower wall part (432) of the horizontal duct section (43), noises due to resonance sounds are reduced.

[Solving Means] The natural frequencies in an upper wall part (431) and the lower wall part (432) of the horizontal duct section (43) are varied from each other. For example, the lower wall part (432) is fixed to a burner body (11) in order to vary the natural frequencies of the upper wall part (431) and of the lower wall part (432) from each other.

A turbulence member is made of a flat plate member configured to be inserted into a heat-transfer tube having a substantially elliptical cross-sectional shape. The flat plate member is a generate turbulence in a fluid flowing inside the heat-transfer tube by a plurality of projected pieces projected on both front and back surfaces. A rotation preventing piece configured to prevent rotation of the flat plate member inside the heat-transfer tube is provided in at least one of both side edges along the flow passage direction in the flat plate member. The rotation preventing piece is provided at a predetermined angle to the flat plate member so that a forefront comes into contact with a tube wall inner circumferential surface of the heat-transfer tube. A space through which the fluid can circulate is formed between the rotation preventing piece and the tube wall inner circumferential surface.

Systems and methods of continuous cooling at cryogenic temperatures. One exemplary aspect involves a refrigeration system that includes: a chamber adapted to hold liquid and gaseous coolant received from a cooling pot; a first adsorption pump having an inlet end in fluid communication with the chamber, the first adsorption pump configured to capture gas from the liquid and gaseous coolant when the first adsorption pump is enabled; a second adsorption pump having an inlet end in fluid communication with the chamber, the second adsorption pump configured to capture gas from the liquid and gaseous coolant when the second adsorption pump is enabled; a means for desorbing the gas captured by the first adsorption pump; and a means for desorbing the gas captured by the second adsorption pump.

The invention relates to a module for a heat pump, comprising an adsorption-desorption region, wherein in the region a bundle of pipes through which fluid can flow is arranged and a housing encloses the pipe bundle and a movable working medium in a sealing manner, wherein a supporting structure forms a mechanical support of a wall of the housing against the action of an external pressure.

A fin includes a cut and raised slit and a cut and raised wall portion. The cut and raised slit is formed in a region adjacent to at least one through hole of a plurality of through holes in a first direction and has a tunnel-shaped hole extending in a second direction intersecting the first direction. The cut and raised wall portion is located in the second direction of the cut and raised slit, protrudes toward a main surface of the fin, and extends along the first direction. Thus, a heat exchanger and a water heater capable of sufficiently conducting an amount of heat of a combustion gas to a heat conduction pipe even in a blind spot of a flow of the combustion gas of the heat conduction pipe and suppressing noise can be realized.

A system and method for heating concrete structures to either prevent the build-up of freezing precipitation or eliminate freezing precipitation on a top surface of the concrete structures. The system includes a heating assembly integrally formed with a concrete structure to apply thermal energy to the top surface of the concrete structure. Optionally, the heating assembly includes heating elements formed of carbon fiber tape. Following formation of the concrete structure, the heating assembly is configured for unified movement with the concrete structure. The system optionally includes a control assembly operatively coupled to the heating assembly. The control assembly selectively powers the heating assembly and can be configured for remote operation. In use, the control assembly can be selectively activated from a remote location to power the heating assembly and heat the concrete structure.

In a primary heat exchanger, a heat conduction pipe is arranged as one connected pipe in a lower stage and an upper stage in a manner extending back and forth through a plurality of fins. The heat conduction pipe is arranged such that a pitch between the heat conduction pipes in the upper stage is shorter than a pitch between the heat conduction pipes in the lower stage. In addition, the heat conduction pipe is arranged such that a position in a center of each heat conduction pipe in the upper stage in a second direction orthogonal to a first direction in which the heat conduction pipe extends and a position in a center of each heat conduction pipe in the lower stage in the second direction are displaced from each other.

Provided is a self-heated enclosure with carbon fiber. An example system can comprise an enclosure defining an interior chamber. The system can comprise at least one electrically conductive carbon fiber member configured in relation to the enclosure to provide a thermal output to the interior chamber when a voltage is applied to the at least one electrically conductive carbon fiber member. The system can further comprise a power source electrically coupled to the at least one electrically conductive carbon fiber member. The power source can be configured to selectively apply the voltage to the at least one electrically conductive carbon fiber member.

A solid state cooler device is disclosed that comprises a first normal metal pad, a first aluminum layer and a second aluminum layer disposed on the first normal metal pad and separated from one another by a gap, a first aluminum oxide layer formed on the first aluminum layer, and a second aluminum oxide layer formed on the second aluminum layer, and a first superconductor pad disposed on the first aluminum oxide layer and a second superconductor pad disposed on the second aluminum oxide layer. The device further comprises a first conductive pad coupled to the first superconductor pad, and a second conductive pad coupled to the second superconductor pad, wherein hot electrons are removed from the first normal metal pad when a bias voltage is applied between the first conductive pad and the second conductive pad.