A heat exchanger for supplying heat includes a housing, a bundle of helical fin-coil tubes, and a flue channel. The housing includes a burner, a water inlet, a water outlet and a flue gas outlet. The burner is disposed on a top portion of the housing and connected to an air/gas mixture unit. The bundle of helical fin-tube coils is disposed tightly, circularly, and coaxially around the burner. The flue channel is disposed below the burner and is formed by a plurality of serpentine bent fin-tube coils. A flow of flue gas vents from the flue channel to the flue gas outlet. The water inlet is connected to the plurality of serpentine bent fin-tube coils which forms the flue channel below the burner. The plurality of serpentine bent fin-tube coils below the burner are connected to the bundle of helical fin-tube coils. The bundle of helical fin-tube coils are connected to the water outlet.

A heat pump system is provided that uses MCM to provide for heating or cooling. The heat pump can include one or more stages of MCM, each stage having an original peak Curie temperature. In the event the magneto caloric response of one or more stages of MCM degrades, the present invention provides for operating the heat pump system so that one or more stages of MCM are held at a different temperature from the original peak Curie temperature so as to restore the MCM to its original peak Curie temperature or to within a certain interval thereof. The present invention can be used with e.g., an appliance, air-conditioning systems (heating or cooling), or other devices using such a heat pump system as well.

A wall construction formed of solid wood members. The wall construction provides for a heating and cooling system that synergistically works with the inherent insulative properties of solid wood members. The wall construction comprises channels formed in the solid wood members to accommodate conduits for heating and cooling. The conduits are routed through multiple solid wood members of a wall and are positioned to efficiently heat and cool the interior of a building. Other grooves may be formed in the top side of the solid wood members to accommodate conduits for heating, cooling electrical service and communications carriers.

Provided is a heat exchanger. The heat exchanger may include a plurality first through third heat exchange pipes connected between a first side part and a second side part, each of which comprising a path of moving heat-exchanger fluid inside; first blisters formed on the outer side surfaces of the first side part and the second side part, thereby connecting gaps between each neighboring first heat exchange pipe; second blisters formed on the outer side surface of the first side part, thereby connecting the first heat exchange pipes with the second heat exchange pipes or the second heat exchange pipes with the third second heat exchange pipes; and third blisters formed on the outer side surface of the second side part, thereby connecting neighboring second heat exchange pipes or neighboring third heat exchange pipes. The second heat exchange pipes may be spaced apart from the first heat exchange pipes and formed above the first heat exchange pipes and the third heat exchange pipes may be spaced apart from the second heat exchange pipes and formed above the second heat exchange pipes.

A water heater includes a primary heat exchanger, a secondary heat exchanger disposed above the primary heat exchanger, a flow path member, and a flow restriction member. The secondary heat exchanger includes a case and heat transfer pipes arranged in the case. The case includes a wall having a gas inlet through which combustion exhaust gas discharged from the primary heat exchanger is introduced into the case. The flow path member connects the primary heat exchanger and the secondary heat exchanger and is disposed adjacent to the gas inlet and is configured to introduce the combustion exhaust gas discharged from the primary heat exchanger into the secondary heat exchanger through the gas inlet. The flow restriction member is disposed on the wall of the case to suppress upward flowing of the combustion exhaust gas that is introduced into the case through the gas inlet.

A magnetocaloric heat generator having an assembly of at least two magnetocaloric modules with a heat transfer fluid flowing through them. The cold ends of the modules are in fluidic communication via a cold transfer circuit and the hot ends are in fluidic communication via a hot transfer circuit. The cold transfer circuit is arranged so that the fluid exiting the cold end of one of the magnetocaloric modules with an exit temperature enters the cold end of the other magnetocaloric module with an entry temperature that is substantially equal to the temperature of the cold end. The hot transfer circuit modifies the temperature of the fluid so that the fluid exiting the hot end of one of the magnetocaloric modules with an exit temperature enters the hot end of the other magnetocaloric module with an entry temperature that is substantially equal to the temperature of the hot end.

A module for warming and, alternately, for cooling, this module comprising an electrocaloric capacitor, an electrical energy storage device and a controllable circuit for transferring electrical energy between the electrocaloric capacitor and the energy storage device. The controllable circuit comprising an inductor connected between the electrocaloric capacitor and the storage device and at least one controllable switch. There is further included a unit programmed to control the switch so as to cause the transfer circuit to toggle successively into the following states and in the following order: an energy recovery state, a disabled state in which it electrically isolates the electrocaloric capacitor and the energy storage device, an energy release state and the disabled state, and each time to maintain the transfer circuit in the disabled state for a duration greater than a predetermined threshold.

The invention relates to a device for cleaning the pipes of the drinking water circuit of an aircraft, in which the device is independent of the aircraft and is connected to the circuit intermittently and supplied with liquid. The device is characterized in that it comprises a mobile chassis supporting a plurality of functional sub-assemblies required to produce a hot liquid, including a closed-furnace gas condensing boiler. The invention can be used to clean the pipes of aircraft.

In various aspects, methods of making perovskite manganese oxide particles are provided as well as perovskite manganese oxide particles made therefrom. The perovskite manganese oxide particles exhibit a strong magnetocaloric effect, making them well suited for applications in power generation and magnetic refrigeration, especially at or near room temperature. The methods can include forming an aqueous mixture of (i) a low-molecular-weight polymeric polyalcohol gel precursor, (ii) a stoichiometric amount of metal salts or hydrates thereof, wherein the metal salts or hydrates thereof comprise at least a Manganese (Mn), and (iii) a polybasic carboxylic acid; polymerizing the aqueous mixture to form a gel containing perovskite manganese oxide nanoparticles entrapped therein; and calcining the gel to remove at least a portion of organic material in the gel and form the perovskite manganese oxide particles. Method and systems are also provided for power generation and magnetic refrigeration using the perovskite manganese oxide particles.

An oil boiler includes an outer container having openings at opposite ends, a combustion chamber that covers an opening at an upper end of the outer container and in which a combustion reaction occurs, a lower cover that covers an opening at a lower end of the outer container, a plurality of flue tubes to heat heating water flowing in the outer container by guiding combustion gas, a burner including a fuel nozzle that sprays fuel, an air nozzle that injects air, and a spark plug that ignites a mixture of the fuel and the air, and a flame tube part that defines a tube space by surrounding a partial space in which the mixture is ignited, the flame tube part including a flame tube having an open lower end and a recirculation hole formed through the flame tube such that the combustion gas is introduced into the flame tube.