A method for operating a waste heat steam generator, in particular one designed according to the forced flow principle, having an evaporator, through which a flow medium flows; an economizer having a number of economizer heating surfaces, and having a bypass line, which on the flow medium side is connected in parallel to a number of economizer heating surfaces. A variable that is characteristic of the heat energy supplied to the waste heat steam generator for controlling or regulating the flow rate of the bypass line is used, wherein the regulating or controlling of the flow rate of the flow medium through the bypass line takes place at the inlet of the evaporator subject to a supercooling target value. The regulating or controlling of the flow rate of the flow medium through the bypass line also takes place at the outlet of the evaporator subject to an overheating target value.

A thermochemical energy storage system. The system includes a membrane-based thermochemical reactor having a solution channel having an absorbent-containing solution flowing therethrough and a refrigerant channel having a refrigerant flowing therethrough along with first and second fluid channels. A porous membrane is positioned between the refrigerant channel and the solution channel; the porous membrane permits flow of vapor molecules therethrough while restricting flow of absorbent molecules. The system further includes a solution storage repository in fluid communication with the solution channel and a refrigerant repository in fluid communication with the refrigerant channel. The system can be used in high-density, high-efficiency, and low-temperature energy storage systems. The membrane-based reactor offers a large specific surface area and integrates solution/refrigerant flows, which enables formation of a highly compact reactor exhibiting strong heat/mass transfer. In some embodiments, direct diffusion of water molecules through the membrane makes it possible to lower the required charging temperatures.

A hot water system and method are provided. The system includes a tank configured to receive hot water, a heat recovery system for heating water, and a controller configured to use the heat recovery system to maintain the hot water in the tank at a temperature within a predetermined range of temperatures. The method involves receiving a flow of water and heating the water using the hot water system.

A heating apparatus comprises a housing (10) with an apparatus volume (15) enclosed thereby. The apparatus comprises a liquid supply (13) for a liquid flow and a liquid discharge (14) for the liquid flow at an increased liquid temperature. The apparatus further comprises a gas inlet (11) for a gas flow. and a gas outlet (12). A heat exchanger (W2) is provided between the gas flow and the liquid flow. A compressor (30) driven by a drive (40) brings the gas flow to an increased pressure and temperature upstream of the heat exchanger (W2). Provided upstream of the gas outlet is a turbine (50) which is driven by the gas flow and which produces an output capacity which is supplied to the drive of the compressor (30). The compressor (30) comprises a mechanical drive (40) which supplements the power supplied by the turbine (50) up to the power consumed by the compressor (30).

A heat exchanger device is disclosed herein. The heat exchanger device includes a dryer-exhaust interface configured to releasably couple with the exhaust port of the clothes dryer and to receive the hot air from a clothes dryer, a heat exchanger configured to exchange heat from the dryer's exhaust to ambient air, and an exhaust outlet that discharges heated air from the exhaust. The device is may useful for recycling hot air from a clothes dryer into a home and help with heating the home.

A passive heat recovery or defrosting apparatus features an evaporator, a condenser, and vapour and liquid conveyance lines connected therebetween. The vapour and liquid conveyance lines respectively connect to upper and lower ends of the evaporator and condenser. The evaporator and/or condenser has a ring-shaped body for fitting around or inline with a pipe to achieve heat exchange relation with a fluid passing therethrough. The evaporator is installed on or inside a warm pipe or duct (e.g. waste drain pipe, clothes dryer exhaust duct, flue pipe, or indoor section of a sewer vent stack) at a lower elevation than the condenser. The condenser is placed on an outdoor end of either a sewer stack or air intake duct for defrosting purposes, or is placed on a water supply line or air intake of a hot water tank, clothes dryer, etc. Working fluid circulates passively between the evaporator and condenser.

A deployable kitchen includes an enclosure, an appliance within the enclosure, and a recapture plenum. The appliance includes a housing and a burner unit that is within the housing. The appliance defines cooling passage between the housing and the burner unit. The cooling passage is in thermal communication with the burner unit such that an airflow through the cooling passage establishes an air buffer between the burner unit and the housing. The housing includes a face that defines an outlet of the cooling passage. The recapture plenum encloses the face of the housing such that the recapture plenum receives an exhaust portion of the airflow after the airflow is conveyed through the cooling passage. The recapture plenum is configured to be in fluid communication with a heating vent within the deployable kitchen.

A preheating heat exchanger allows heat exchange between cooling water on an outlet side of an auxiliary cooling heat exchanger and supply water that has passed through a preheating bypass path.

The invention relates to a method and apparatus for low temperature waste heat utilization. In the scope of the hot water plant (HWP) there are few low temperature sources, which cannot be used by heat consumer (HC) directly. The method and apparatus for hot water power plant (HWP) waste heat recovery comprises at least one, preferably condensing type heat exchanger (HE), which collects the waste heat for water source high temperature heat pump (HP) employment, wherein a low temperature heat is upgraded to a high temperature heat, hence heat pump (HP) hot water outlet is fed to the boiler in a return line or in a supply line of hot water plant (HWP), wherein the thermal energy balance adjustment of generated heat is executed by adapting the power of said heat pump (HP) and/or by adapting the power of said furnace and/or by adapting the mass flow of the primary heat transfer medium in at least one open loop heating network and/or in at least one closed loop heating circuit in the scope of heat distribution network.

There is herein described energy storage systems. More particularly, there is herein described thermal energy storage systems and use of energy storable material such as phase change material in the provision of heating and/or cooling systems in, for example, domestic dwellings.