A heating system (1) has a turbine (20) for burning a fuel to provide flue gas and electrical energy. A flue gas heat exchanger (25) receives the flue gas and uses it to heat water in three of stages. An air conduit (2) receives inlet air (3) and gases from secondary inlets (5, 26) from within the system to elevate the temperature in the main conduit (2) above ambient. An evaporator (8) recovering heat from the air flow of the main conduit, and provides energy via an evaporator coil to an air source heat pump ASHP (50). A water source heat pump WSHP (60) receives a water feed at an elevated temperature from the ASHP (50), and it cools the flue gas in a third heat exchanger stage (25(c)). Hence, WSW efficiency is high and it provides product water, as do the first and second stages of the flue gas heat exchanger (25)

A method and an arrangement for recovering heat from flue gas of a boiler (10). The method comprises passing the flue gas (G) of the boiler though a flue gas cooling unit (1), cooling the flue gas (G) by transferring heat from the flue gas (G) into a circulation (3) of a flue gas cooling liquid (CL), transferring heat energy of said flue gas cooling liquid (CL) into a heat pump (2), and arranging the heat pump (2) for receiving heat energy also from a circulation arrangement (8) of a district cooling system. The heat pump (2) is coupled to a circulation arrangement (6) of a district heating system, wherein the method further comprises transferring in the heat pump (2) heat energy (H) received from said cooling liquid (CL) and from said circulation arrangement (8) of district cooling system into said circulation arrangement (6) of district heating system, for lowering the temperature of said flue gas cooling liquid (CL) and cooling fluid of said district cooling system, and raising the temperature of heating fluid of said district heating system.

A dual heating process is performed in the absence of an open flame. Heat is created by a rotating prime mover(s) driving a fluid shear heater. Heat is also collected from a cooling system of the prime mover, and from any exhaust heat generated by the prime mover. The heat energy collected from all of these sources is transmitted through heat exchangers to a fluid where heat energy is desired. The fluid being heated may be glycol or air, depending on the type of heat desired.

A dual heating process is performed in the absence of an open flame. Heat is created by a rotating prime mover(s) driving a fluid shear heater. Heat is also collected from a cooling system of the prime mover, and from any exhaust heat generated by the prime mover. The heat energy collected from all of these sources is transmitted through heat exchangers to a fluid where heat energy is desired. The fluid being heated may be glycol or air, depending on the type of heat desired.

An energy system includes a turbine flue heat exchanger feeding a storage tank arranged to deliver water on a high temperature (90° C.) line to supply circuits. A heat pump and storage tank are arranged to deliver lower temperature (45° C.) water on a low temperature line to the supply circuits. A number of the supply circuits are each arranged to receive high temperature water, receive low temperature water, and use these flows to deliver a process water supply at a desired high, low or intermediate temperature (65° C.). In some each supply circuits the blending is controlled by control of a low temperature line pump according to temperature of the process outlet. The low temperature tank is supplied by a heat pump the inlet of which is fed by a heat recovery heat exchanger which recovers waste heat from a plant, and so it is more efficient than if it received cold water. Electrical energy for the heat pump is at least partly supplied by the high temperature heater gas turbine. Overall, the system has excellent energy efficiency due to the manner in which waste heat is utilized, improved efficiency of a heat pump, and real time control of the high and low water lines.

A water heater according to the present invention includes: a heating unit that includes a burner provided to cause a combustion reaction from air and fuel, and that is provided to generate heated water by using heat generated by the combustion reaction; and a humidifier unit that generates water steam by evaporating water using a combustion gas generated by the combustion reaction and discharged from the heating unit, and provides the water steam together with the air to the burner.

A hybrid heating system having a heat recovery apparatus in fluid communication with a heat pump and a furnace is provided. The apparatus recovers heat from flue gas discharged from the furnace and transfers the recovered heat to a stream of refrigerant in the heat pump. The apparatus includes a shell disposed in fluid communication with the furnace and tubes disposed in fluid communication with the shell and the heat pump. The system includes valves for regulating access between the apparatus and the stream of the refrigerant in the heat pump, and a control unit in communication with the valves to regulate access between the apparatus and the heat pump during a heating mode based on operating parameters of the system.

Heat from a rotating prime mover(s) driving a fluid shear pump, heat from the prime mover and any exhaust heat generated by the prime mover is collected. The heat energy collected from all of these sources is transmitted through heat exchangers to a fluid where heat energy is desired. This fluid heating process is performed in the absence of an open flame.

The present disclosure discloses a heat exchange pipe, a heat exchanger and a water heating apparatus. The heat exchange pipe comprises: a pipe body and a plurality of fins fixedly disposed to sleeve the pipe body; a flow guiding structure is provided at a partial outer edge of the fin; and a flow guiding flue is formed between the flow guiding structure and an outer wall of the pipe body. The heat exchange pipe, the heat exchanger and the water heating apparatus provided by the present disclosure can improve the flue gas flow path and the heat exchange efficiency.

A hybrid heating system having a heat recovery apparatus in fluid communication with a heat pump and a furnace is provided. The apparatus recovers heat from flue gas discharged from the furnace and transfers the recovered heat to a stream of refrigerant in the heat pump. The apparatus includes a shell disposed in fluid communication with the furnace and tubes disposed in fluid communication with the shell and the heat pump. The system includes valves for regulating access between the apparatus and the stream of the refrigerant in the heat pump, and a control unit in communication with the valves to regulate access between the apparatus and the heat pump during a heating mode based on operating parameters of the system.