A device and method for treating a wound of a patient with negative pressure is provided. The device comprises a heat-assisted pump system. The pump system can be powered in part by heat derived from the patient. The pump system may be configured to be highly planar, light weight, and portable. The pump system may comprise a Stirling engine or a thermal acoustic engine.

The subject of this invention is a method of heat transfer in the embedded structure of a heat regenerator and the design thereof. It regards the related heat regenerators, which operate on the principle of the described method and enable a reduction of the pressure drop due to the fluid flow through the heat regenerator and consequently an increase of the power density. The concept of the operation of the heat regenerator by this invention, in which for the oscillation of the flow of the primary (first) fluid (P), electromechanical elements are applied. In the housing (1) between the elements (2) for the oscillation of the primary (first) fluid (P), there are positioned a primary hot heat exchanger (PT) and a primary cold heat exchanger (PH). In the direction of the arrow (A) the unidirectional flow of the secondary (second) fluid (S) flows from the heat sink into the primary cold heat exchanger (PH). In the direction of the arrow (B) the unidirectional flow of the secondary (second) fluid (S) exits from the primary cold heat exchanger (PH) and flows towards the heat source. Meanwhile, in the direction of the arrow (C), the unidirectional flow of the secondary (second) fluid S enters the primary hot heat exchanger (PT) and exits in the direction of the arrow (D) as the unidirectional flow of the secondary (second) fluid S of the primary hot heat exchanger (PT) towards the heat sink. Between both primary heat exchangers, (PT) and (PH), the porous regenerative material is positioned, which is part of the regenerator 4, with the hydraulically separated segments.

A modular thermal apparatus for performing transformation between thermal and acoustic energy is disclosed and includes a housing, first and second fluid ducts extending therethrough, and a regenerator having axially extending regenerator fluid passages. A first heat exchanger conducts thermal energy in the axial direction and includes transversely oriented fluid passages extending through a thermally conductive body and changing direction within the body to terminate axially aligned with the regenerator fluid passages. The apparatus also includes a second heat exchanger having fluid passages extending through a thermally conductive body and terminating in fluid communication with the regenerator fluid passages. Thermal energy is transferred between the heat exchangers and an external thermal energy source or sink. The housing withstands a pressure associated with a pressurized working gas and the fluid ducts provide for connection of the apparatus as a module within an acoustic power loop.

A thermoacoustic device includes a stage coupled to a bar, wherein the stage includes a first heating component on a first terminus of the stage. The stage further includes a first cooling component on a second terminus of the stage. A thermal conductivity of the stage is higher than a thermal conductivity of the bar. A heat capacity of the stage is higher than a heat capacity of the bar.

A device and method for treating a wound of a patient with negative pressure is provided. The device comprises a heat-assisted pump system. The pump system can be powered in part by heat derived from the patient. The pump system may be configured to be highly planar, light weight, and portable. The pump system may comprise a Stirling engine or a thermal acoustic engine.

A thermoacoustic transducer apparatus is disclosed including at least one thermal converter operable to provide power conversion between acoustic power and thermal power in a pressurized working gas contained within a working volume, a portion of which extends through the thermal converter. The thermoacoustic transducer is operable to cause a periodic flow in the working gas during operation. The apparatus also includes a reservoir volume in fluid communication with the working volume through a conduit having a working volume end in fluid communication with the working volume and a reservoir volume end in fluid communication with the reservoir volume. The conduit has a bore size and length operable to cause pressure oscillations at the working volume end to be converted to flow oscillations at the reservoir volume end such that periodic fluid flow at the reservoir volume end is at least twice as large as periodic fluid flow at the working volume end thereby facilitating a steady fluid flow along the conduit for equalization of working gas static pressures between the working volume and the reservoir volume while providing a sufficiently high acoustic impedance at the working volume end to minimize losses due to periodic flows of working gas within the conduit.

Disclosed are a thermoacoustic engine with high conversion efficiency from heat energy to acoustic energy and a designing method for the thermoacoustic engine. A stack of the thermoacoustic engine has a plurality of flow passages extending through a thermoacoustic piping section. A hot heat exchanger is coupled to one end in a longitudinal direction of the stack. A cold heat exchanger is coupled to the other end in the longitudinal direction of the stack. And a length in the longitudinal direction of the hot heat exchanger is greater than a length in the longitudinal direction of the stack, and is greater than a length in the longitudinal direction of the cold heat exchanger.

A thermoacoustic device includes a loop tube in which a working gas is sealed; a stack in which a temperature gradient is generated in a tube axis direction of the loop tube, the stack being provided in the loop tube; and a diaphragm structure including a diaphragm provided in the loop tube and an operating unit, the diaphragm having a surface extending in a direction intersecting the tube axis direction and being configured to vibrate with a component of vibration in the tube axis direction, and the operation unit being configured to apply a physical quantity that is required, to the diaphragm to change a rigidity of the diaphragm in the tube axis direction.

An apparatus for performing energy transformation between thermal energy and acoustic energy is in a thermoacoustic transducer apparatus is disclosed. The acoustic energy is associated with a periodic flow of a working fluid within an acoustic power loop of the thermoacoustic transducer. The apparatus includes a common central plenum having a first fluid port for providing fluid communication with the acoustic power loop, and a plurality of discrete cylindrical thermal converters radially arranged about the plenum, each thermal converter including a regenerator. The apparatus also includes a second fluid port for providing fluid communication between the thermal converter and the acoustic power loop, and fluid flow passages in fluid communication with the plenum and extending through the regenerator to the second fluid port.

An energy conversion device includes a first acoustic wave generator, a second acoustic wave generator, and an output unit which are provided in a pipe member. The first acoustic wave generator has a thermal energy generator configured to generate thermal energy from electric energy, and converts the thermal energy generated by the thermal energy generator into acoustic energy to generate acoustic wave in working gas by a self-excited thermo acoustic vibration. The second acoustic wave generator converts thermal energy supplied from a heat supply source into acoustic energy and generates acoustic wave in working gas by a self-excited thermo acoustic vibration. The output unit converts the acoustic energy of the acoustic waves from the first acoustic wave generator and the second acoustic wave generator into cold energy to output.