Patent classifications
F22D5/26
Feedwater control for a forced-flow waste-heat steam generator
A method for operating a forced-flow steam generator constructed as a waste-heat steam generator having a pre-heater, including pre-heater heating surfaces, and having an evaporator including evaporator heating surfaces connected downstream on the flow medium side of the pre-heater heating surfaces. A device for adjusting a feed water mass flow has a set point for the feed water mass flow. During the creation of the set point for the feed water mass flow, a waste-heat flow transferred to a fluid in the evaporator heating surfaces is determined, and mass storage and energy storage in the fluid in the evaporator heating surfaces is detected during non-steady-state plant operation. A behaviour over time of a mass storage in the evaporator is coupled with a behaviour over time of a mass storage in the pre-heater, wherein scaling is carried out with a ratio of the density changes in the evaporator and pre-heater.
METHOD FOR SETTING PARAMETERS OF LOAD FEEDFORWARD CONTROLLER FOR SUPERHEATED STEAM TEMPERATURE CONTROL
Disclosed is a method for setting parameters of a load feedforward controller for superheated steam temperature control, which belongs to the technical field of thermal automatic control. This method adds a load feedforward controller to the conventional boiler superheated steam temperature spray desuperheating cascade control system. The application provides a structure of the load feedforward controller, and a method for designing the parameters of the load feedforward controller according to the dynamic characteristics of the superheated steam temperature related to feed coal flow disturbance, feedwater flow disturbance and desuperheating water spray disturbance. The method of the application could effectively reduce the superheated steam temperature deviation in the process of unit load rise or drop, and the design method is simple, effective and easy to realize in engineering.
Steam generator for fuel cell applications
A steam vaporizer assembly includes an internal steam generator having a vessel configured to hold water, a vaporizer unit having a heating element configured to heat the water to generate saturated steam; and a controller configured to: cause the heating element to heat the water to a stand-by temperature; and while maintaining a water level of the water in the vessel between two control points: maintain the water in the vessel at the stand-by temperature until steam generation is required, and when steam generation is required, heating the water in the vessel from the stand-by temperature to a temperature at or above a vaporization temperature of the water using a heating element, to generate the steam.
Steam generator for fuel cell applications
A steam vaporizer assembly includes an internal steam generator having a vessel configured to hold water, a vaporizer unit having a heating element configured to heat the water to generate saturated steam; and a controller configured to: cause the heating element to heat the water to a stand-by temperature; and while maintaining a water level of the water in the vessel between two control points: maintain the water in the vessel at the stand-by temperature until steam generation is required, and when steam generation is required, heating the water in the vessel from the stand-by temperature to a temperature at or above a vaporization temperature of the water using a heating element, to generate the steam.
Method for improving efficiency of Rankine cycle
A method for improving the efficiency of a Rankine cycle by reducing cold end loss, comprising: for a Rankine cycle with a reheat-cycle, reducing temperature of reheat steam or removing a reheat steam system, and for a Rankine cycle with regenerative steam extraction-heat, reducing temperature of main steam and increasing humidity of main steam.
STEAM COOKING APPARATUS AND METHOD
Provided is a cooking apparatus (10). The cooking apparatus comprises a food chamber (12), and a steam supply (16, 20, 23) for supplying steam to the food chamber. A control arrangement (22, 28) controls the steam supply to maintain a steam concentration in air inside the food chamber which is below saturation. Further provided is a method of cooking.
ELECTRONIC COOKING APPARATUS HAVING STEAM SUPPLY DEVICE
An electronic cooking apparatus having a steam supply device for supplying steam to a cooking chamber of an oven is provided. The electronic cooking apparatus may include a steam generating device including a steam supply portion that generates steam and supplies the steam to a cooking chamber, and a water level sensing module that senses a level of water inside of the steam supply portion using a low water level sensor and a high water level sensor. In addition, the electronic cooking apparatus may include a water supply pump that supplies water from a water tank to the steam supply portion; a drain pump that collects condensed water from the steam supply portion to the water tank; and a controller that controls on/off operations of the water supply pump or the drain pump according to a change in the level of water in the steam supply portion sensed by the water level sensing module.
STEAM BOILER SYSTEM AND METHOD OF CIRCULATING WATER AND STEAM IN A STEAM BOILER SYSTEM
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.
STEAM BOILER SYSTEM AND METHOD OF CIRCULATING WATER AND STEAM IN A STEAM BOILER SYSTEM
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.
Control method for optimizing generated power of solar-aided coal-fired power system under off-design working conditions
A control method for optimizing generated power of a solar-aided coal-fired power system under off-design working conditions sets maximizing generated power without changing main steam flow rate as a control goal. A solar-coal feedwater flow distribution ratio is adjusted to adjust water flow rate heated by a solar heat collection system, so as to achieve the control goal. Control steps include reading relevant information; calculating the water flow rate range heated by the solar heat collection system, and an applicable solar-coal feedwater flow distribution ratio range; establishing a correspondence between the generated power and the solar-coal feedwater flow distribution ratio within this range; selecting a solar-coal feedwater flow distribution ratio corresponding to the maximum generated power; and adjusting the water flow rate entering the solar heat collection system to an optimized value. The present invention can flexibly control the solar-coal coupling and improve the economy.