A steam generation apparatus includes: a heat medium flow passage through which a heat medium flows; a primary economizer disposed in the heat medium flow passage; a secondary economizer disposed in the heat medium flow passage at an upstream side of the primary economizer with respect to a flow direction of the heat medium; a primary evaporator disposed in the heat medium flow passage at an upstream side of the secondary economizer with respect to the flow direction of the heat medium; a first flash tank for generating flash steam; a first feed water line configured to supply water heated by the primary economizer to the secondary economizer; and a second feed water line disposed so as to branch from the first feed water line and configured to supply the water heated by the primary economizer to the first flash tank.

A steam generation apparatus includes: a heat medium flow passage through which a heat medium flows; a primary economizer disposed in the heat medium flow passage; a secondary economizer disposed in the heat medium flow passage at an upstream side of the primary economizer with respect to a flow direction of the heat medium; a primary evaporator disposed in the heat medium flow passage at an upstream side of the secondary economizer with respect to the flow direction of the heat medium; a first flash tank for generating flash steam; a first feed water line configured to supply water heated by the primary economizer to the secondary economizer; and a second feed water line disposed so as to branch from the first feed water line and configured to supply the water heated by the primary economizer to the first flash tank.

A control method for operating a heat recovery steam generator having a flue gas channel in which an evaporator, having at least two evaporator heating surfaces arranged successively in the flue gas channel and at least one intermediate heating surface arranged between the evaporator heating surfaces, is provided, the method including determining a characteristic value characteristic of the heat absorption in the evaporator for the evaporator heating surfaces, additionally determining for the at least one intermediate heating surface, an additional characteristic value for the heat absorption of the intermediate heating surface, and subtracting this additional characteristic value from the characteristic value characteristic of the heat absorption in the evaporator.

A control method for operating a heat recovery steam generator having a flue gas channel in which an evaporator, having at least two evaporator heating surfaces arranged successively in the flue gas channel and at least one intermediate heating surface arranged between the evaporator heating surfaces, is provided, the method including determining a characteristic value characteristic of the heat absorption in the evaporator for the evaporator heating surfaces, additionally determining for the at least one intermediate heating surface, an additional characteristic value for the heat absorption of the intermediate heating surface, and subtracting this additional characteristic value from the characteristic value characteristic of the heat absorption in the evaporator.

The steam boiler system comprises a steam boiler comprising a burner and a chimney for exhausting flue gases, a feedwater line for leading feedwater to said steam boiler for producing steam, a steam line leading from said steam boiler to at least one application heat exchanger for feeding steam to said application heat exchanger, said application heat exchanger for heating an application fluid, and a condensate line leading away from said application heat exchanger for recuperating condensate from said application heat exchanger. An economizer heat exchanger is provided in said chimney, wherein at least one of said condensate return line and said feedwater line circulates through said economizer heat exchanger for allowing at least one of said condensate and said feedwater to be in heat exchange relationship with the flue gases for simultaneously cooling the flue gases while heating at least one of the condensate and the feedwater.

The steam boiler system comprises a steam boiler comprising a burner and a chimney for exhausting flue gases, a feedwater line for leading feedwater to said steam boiler for producing steam, a steam line leading from said steam boiler to at least one application heat exchanger for feeding steam to said application heat exchanger, said application heat exchanger for heating an application fluid, and a condensate line leading away from said application heat exchanger for recuperating condensate from said application heat exchanger. An economizer heat exchanger is provided in said chimney, wherein at least one of said condensate return line and said feedwater line circulates through said economizer heat exchanger for allowing at least one of said condensate and said feedwater to be in heat exchange relationship with the flue gases for simultaneously cooling the flue gases while heating at least one of the condensate and the feedwater.

The present application provides a method of adjusting a feedwater mass flow rate to maintain a constant steam temperature in an evaporator section. The method may include the steps of determining a change in a number of operational parameters, predicting a change in steam temperature based on the number of operational parameters, combining the predicted changes in steam temperature, determining a feedforward signal based on dynamically offsetting the combined predicted changes in steam temperature, and changing the mass flow rate of feedwater based on the feedforward signal.

Systems and methods are disclosed for producing a superheated steam having a specified ratio of water vapor to combustion gases for injection into a well to enhance heavy oil production. Embodiments comprise indirect-contact steam generators and direct-contact steam generators.

An economizer having a structure capable of efficiently warming water and facilitating inspection and cleaning is obtained.

In an economizer for warming water by combustion exhaust gas generated by a boiler, to a cylindrical water pipe in which an inflow port and an outflow port are formed on a side surface and through which the water passes, a plurality of gas pipes erected for circulating the combustion exhaust gas are arranged in corresponding fan-shaped portions of the water pipe. The combustion exhaust gas introduced from a bottom surface side of the water pipe folds back at an upper part of the water pipe and flows downward, then folds back at a lower part of the water pipe, flows upward, and flows out from an upper surface side of the water pipe, whereby the plurality of gas pipes efficiently warms the water in the water pipe.

An economizer having a structure capable of efficiently warming water and facilitating inspection and cleaning is obtained.

In an economizer for warming water by combustion exhaust gas generated by a boiler, to a cylindrical water pipe in which an inflow port and an outflow port are formed on a side surface and through which the water passes, a plurality of gas pipes erected for circulating the combustion exhaust gas are arranged in corresponding fan-shaped portions of the water pipe. The combustion exhaust gas introduced from a bottom surface side of the water pipe folds back at an upper part of the water pipe and flows downward, then folds back at a lower part of the water pipe, flows upward, and flows out from an upper surface side of the water pipe, whereby the plurality of gas pipes efficiently warms the water in the water pipe.