Disclosed is a two-stage heating geothermal system using geothermal energy. The two-stage heating geothermal system includes a geothermal heat exchanger, a geothermal heat pump, a booster heat pump, a bypass line, and a bypass line opening and closing valve. The operating efficiency of the two-stage heating geothermal system using geothermal energy is significantly improved. Hot water supply, auxiliary heating, and the like are controlled to be completely independent of main heating.

A thermodynamic system and method for performing work includes a working fluid and a fluid pump for pumping the working fluid through a cycle. A thermal input supplies heat to the working fluid. An expansion device downstream of the thermal input converts at least the heat of the working fluid to useful work. A heat exchanger downstream of the expansion device has a first portion to transfer heat from downstream said expansion device to a second portion at or upstream of said thermal input. A conversion device expands the working fluid with constant enthalpy from a higher to a lower pressure.

Regasification systems and processes for converting liquid natural gas (LNG) from a liquid into a gaseous state are described. The process includes a closed-loop system that uses geothermal wells as a heat source. A warming fluid circulates through the closed-loop system coupled with a geothermal well and a LNG heat exchanger. The warming fluid is heated as it passes through the geothermal well and cooled as it passes through the LNG heat exchanger, thus heating and gasifying the LNG. The cooled warming fluid then returns to the geothermal well. The closed-loop system minimizing environmental impact by eliminating the need to discharge the warming fluid.

A direct contact condenser for a steam turbine having an exhaust steam flow hood and a condenser connected to the hood. The condenser includes a downward flow condensing cell having a first liquid distribution assembly a first heat exchange media disposed below the first liquid distribution assembly. The condenser also includes an upward steam flow cooling cell and a second liquid distribution assembly along with a second heat exchange media disposed below the second liquid distribution assembly.

An arrangement for storing thermal energy, including a shaft (1) and at least one tunnel (2), the shaft (1) and the tunnel (2) being in fluid communication with each other. The tunnel (2) includes at least a first (2a), a second (2b), and a third (2c) tunnel section. The second tunnel section (2b) is arranged between and connected to the first (2a) and third (2c) tunnel sections. The second tunnel section (2b) is sealed off at an end (4) connected to the third tunnel section (2c), and the third tunnel section is further connected the shaft (1). The shaft (1) and first (2a) and third (2c) tunnel sections hold fluid for thermal storage. The second tunnel section (2b) is an expansion space should a volume of the fluid expand beyond a volume of the shaft (1) and the first (2a) and third (2c) tunnel sections.

Methods for thermalsiphoning supercritical CO.sub.2 within a geothermal formation includes providing a geothermal energy system that includes an underground hot rock reservoir, a production well, and an injection well that together form a fluid path suitable for circulating supercritical CO.sub.2. The supercritical CO.sub.2 flows by thermosiphoning. Thermosiphoning is maximized by maintaining a pressure between 1400-4000 psia, an injection temperature in a range from 50-200 C and a production temperature in a range from 150-600 where injection temperature and the production temperature differ by at least 50° C.

A refrigeration appliance includes a refrigeration circuit having a condenser and a heat circulation system for heating an element of the refrigeration appliance. The heat circulation system includes a heat conducting region. A heat exchanging element includes the condenser and the heat conducting region. The condenser and the heat conducting region in the heat exchanger element are thermally coupled in order to output heat from the refrigeration circuit to the heat conducting region of the heat circulation system.

A district public water supply pipe network system compatible for ground source heat pump water and reclaimed water comprises a water supply main pipe connected with a reclaimed water outlet side of a sewage treatment system and connected to a plurality of energy stations and a plurality of transmission and distribution station, and a return water main pipe arranged between the adjacent energy stations to connect them. The energy stations are provided with a plurality of shallow geothermal heat exchange system for exchanging heat with shallow geothermal energy in the region. Both the energy stations and the transmission and distribution station are connected with corresponding distribution pipe networks connected with a user terminal water supply system. The system provides the source side water and the reclaimed water to users. It is a district public geothermal pipe network and a reclaimed water pipe network.

A geothermal heat exchange apparatus is disclosed that comprises a flexible assembly of a plurality of pipes twisted on a central conduit. The central conduit has a tubular structure. The plurality of pipes is twisted around the central conduit. The plurality of pipes is adapted to connect to an external environmental control system that supplies a heat exchange liquid for the transfer of heat through the plurality of pipes. The geothermal heat exchange apparatus is adapted for positioning in a hole in the earth for the exchange of heat.

An arrangement for storing thermal energy has at least two tunnels (1a, 1b) for holding a fluid. The tunnels (1a, 1b) are connected to each other by at least one channel (2), such that fluid communication is allowed between the tunnels (1a, 1b). Each of the inner tunnel (1a) and the outer tunnel (1b) is configured as a helix, the inner tunnel (1a) forming an inner helix and the outer tunnel (1b) forming an outer helix.