A system for converting thermal energy into electrical power includes a temperature-sensitive element held in a frame by its two ends between a heat source and a cold source producing a thermal gradient. A piezoelectric element is positioned between the frame and at least one end of the temperature-sensitive element. The temperature-sensitive element is configured to deform cyclically between two states under the action of the thermal gradient. With each cyclic deformation, a stress is applied to the piezoelectric element via the one end.

The present invention discloses a device capable of converting thermal energy into kinetic energy, in particular a thermal-powered device, including a housing (1) and a transmission device (2) disposed in the housing (1). Alloy sheets (3) are disposed at the transmission device (2). The housing (1) is formed with a heat source interface (6). In the present invention, thermal energy or other energy in the automobile exhaust gas is converted into kinetic energy output by virtue of the memory function of memory alloys, thus reducing emission of greenhouse gas, protecting the atmosphere environment, and conforming to the strategies and policies of economy of energy, environmental protection, and harmonious development between man and nature.

A method and system for providing an engine for producing mechanical energy through the absorption and evaporation of moisture uses a hygroscopic material in one or more configurations to do mechanical work. The hygroscopic material can include microbial spores, plant cells and cell materials, silk and hydrogel materials that absorb moisture and expand or swell when exposed to high relative humidity environments and shrink or return to nearly their original size or shape when exposed to low relative humidity environments wherein the moisture evaporates and is released. By exposing the hygroscopic material to a cycle of high relative humidity environments and low relative humidity environments, useful work can be done. One or more transmission elements can be used to couple the hygroscopic material to a generator that converts the mechanical energy to, for example, electrical energy. The hygroscopic material can be applied to flexible sheet materials that flex as the hygroscopic material absorbs or evaporates moisture. The hygroscopic material can also be applied to elastic conductive materials, such that the plates of a capacitor mechanically change the capacitance of the device.

Evaporation-driven engines are disclosed herein. An example engine can include a water source having a high humidity zone proximate the surface of the water source, a supporting structure, and a hygroscopic material disposed on the supporting structure and configured to generate mechanical force in response to a changing relative humidity. The hygroscopic material can be repeatedly exposed to the high humidity zone and removed from the high humidity zone thereby causing the hygroscopic material to generate mechanical force.

The invention relates to a solar-powered apparatus, comprising a housing (1), a shield panel (5) disposed on the housing (1), and a transmission apparatus (2) disposed inside the housing (1). The transmission apparatus (2) is provided with eight or more memory alloy sheets (3). The housing (1) is also provided with a ratchet pawl (13). The shield panel (5) is provided with a light-focusing apparatus (51) used for focusing light. The apparatus is capable of converting solar energy into mechanical energy.

A thermal energy system includes a heat source configured to produce heat, a device configured to use the heat produced by the heat source to produce energy, and a thermal battery configured to store the heat produced by the heat source and transfer the heat to the device for use by the device. The thermal battery includes a thermal-storage mass having coal ash.

An aircraft propulsion system includes a core engine assembly that generates an exhaust gas flow, a bottoming cycle that includes a bottoming fluid flow that is expanded through a bottoming turbine, a first heat exchanger where heat from the exhaust gas flow is transferred to heat the bottoming fluid flow, and a second heat exchanger where heat from a secondary heat source is transferred to heat the bottoming fluid flow. The second heat exchanger is disposed upstream of the first heat exchanger such that heat from the secondary heat source preheats the bottoming fluid flow prior to accepting heat from the exhaust gas flow in the first heat exchanger.

A method of operating a nuclear power system includes generating heat in a nuclear reactor core, transmitting the heat to a heat engine, generating electricity with a generator operatively coupled to the heat engine. The method further includes detecting a no-load condition, and stopping the heat engine. The method also includes transferring heat from an outer surface of the nuclear reactor to the environment through a heat transfer system if a temperature of the nuclear reactor rises above a threshold temperature. The method further includes preventing heat from transferring from the outer surface of the nuclear reactor to the environment through the heat transfer system if the temperature of the nuclear reactor is below the threshold temperature. Nuclear power systems and nuclear reactors are also disclosed.

A shape memory material element configuration. The element includes a shape memory material element, and a capillary line extending to the element, and positioned to apply an activation fluid to the element.

A flow control system for controlling multiphase formation fluid flow in a wellbore may comprise an electric submersible pump, an intake screen, a controller, a sensor, and a heating component, wherein: the intake screen comprises a shape memory alloy (SMA) mesh configured to perform a reversible modification between a first shape and a second shape; the sensor is configured to measure one or more fluid properties; the controller is communicably coupled to the sensor and the heating component and is configured to: determine whether the one or more fluid properties fall outside a predetermined tolerance at the controller, and actuate the heating component upon determining the one or more fluid properties fall outside the predetermined tolerance; and the heating component is configured to modify the SMA mesh from the first shape to the second shape when actuated, and thereby to control the multiphase formation fluid flow through the intake screen.