Steam generating apparatus and methods
AssigneeThe Garrett Corporation
InventorEdward A. Mock
Life of this patent
Estimating the term…
Abstract
Steam generating apparatus and methods wherein a liquid is recirculated within a boiler by use of a constant speed dynamic feed water pump acting both to feed the boiler and to effect recirculating therein by a jet pump with its jet nozzle in liquid flow series with the dynamic pump. The jet pump also receives water from a steam drum for recirculation through the boiler. In the event of excess feed water supply to the boiler a step-function level control for the steam drum bypasses liquid to a condenser. A second jet pump acts to utilize excess feed water to supply cool water from the condenser well under pressure to the dynamic pump so that no water is bypassed to the condenser under on-design operating conditions. For waste heat recovery to provide shaft power automatically with simplified controls.
Claims50
Apparatus comprising heat exchange means for placing a liquid in heat exchange relation with a source of heat to promote boiling of said liquid, collecting means in association with said heat exchange means for receiving heated liquid from the latter and collecting the vapor resulting from boiling of said liquid, liquid feed means for pressurizing liquid from a low pressure source thereof and for delivering a flow of said pressurized liquid to said heat exchange means, and means for recirculating liquid from said collecting means to said heat exchange means in response to said flow of pressurized liquid, said apparatus further includes a sensor responsive to a liquid level in said collecting means to produce a signal, means defining a liquid flow path from said collecting means to said low pressure liquid source, and valve means opening and closing said liquid flow path in response to said signal thereby to limit the liquid level in said collecting means, wherein said liquid feed means draws liquid from said low pressure liquid source via a jet pump for delivery to said heat exchange means, said liquid flow path including a branch upstream of said valve means which communicates with a high pressure inlet of said jet pump, whereby pressurized liquid flow from said collecting means to said liquid feed means via said jet pump entrains liquid from said low pressure liquid source and flows therewith to said liquid feed means.
In a steam generator comprising a boiler with steam receptacle means receiving both pressurized liquid and vapor for substantially separating same, the method of controlling the liquid level within said steam receptacle means comprising the steps of:
- utilizing a dynamic liquid pressure generating pump to supply pressurized liquid from a relatively low pressure source to said boiler;
- utilizing a flow-restricting orifice between said dynamic pump and said boiler to regulate the liquid flow rate to the latter;
- sensing said liquid level within said steam receptacle;
- and
- draining liquid from said steam receptacle to said low pressure source in response to said sensed liquid level;
- utilizing pump means responsive to said supply of pressurized liquid from said dynamic pump to said boiler for recirculating liquid from said steam receptacle means through the remainder of said boiler;
- utilizing a jet pump to define said pump means;
- utilizing a nozzle of said jet pump to define said flow-restricting orifice;
- employing said jet pump nozzle to form said supply of pressurized liquid into a relatively high velocity liquid jet;
- utilizing said liquid jet entrain liquid from said steam receptacle for recirculating same through the remainder of said boiler;
- conserving thermal energy carried from said steam receptacle toward said low pressure source by liquid draining from the former toward the latter by transferring said thermal energy to said supply of pressurized liquid;
- and
- conserving pressure energy carried from said steam receptacle toward said low pressure source by liquid draining from the former toward the latter by using said pressure energy to induce liquid flow from said low pressure source to said dynamic pump.
In a apparatus having heat exchange means for placing a liquid in heat exchange relation with a heat source, collecting means in association with said heat exchange means for receiving heated liquid therefrom and collecting the vapors resulting from boiling of said liquid, and liquid feed pump means for pressurizing liquid from a relatively low pressure source thereof and for delivering a flow of said pressurized liquid to said heat exchange means, the method of providing for recirculation of heated liquid from said collecting means to said heat exchange means, said method comprising the steps of:
- utilizing a circulating pump capable of being powered by a flow of pressurized liquid;
- providing for said circulating pump to receive liquid from said collecting means and to discharge said liquid to said heat exchange means;
- and utilizing said flow of pressurized liquid from said feed pump means to power said circulating pump;
- further including the steps of:
- using two pumps in liquid flow series to substantially define said liquid feed pump means, one of said two pumps including a substantially constant speed dynamic pump whose fluid flow rate is inversely dependent upon the fluid pressure differental thereacross, the other of said two pumps including a jet pump having an inlet receiving a first flow of liquid from said low pressure source, said jet pump also including a high pressure inlet receiving a second flow of liquid from said collecting means and an outlet delivering said first and said second flows together to said dynamic pump;
- and adjusting the flow rate of said second flow in dependence upon the fluid pressure level within said collecting means thereby to adjust the flow rate of said first flow.
In an apparatus having a boiler with a steam drum, and a liquid feed pump providing a flow of pressurized liquid to said boiler, the method of providing liquid recirculation within said boiler comprising the step of using said flow of pressurized liquid to power liquid recirculation from said steam drum through the remainder of said boiler and back to said steam drum;
- utilizing a jet type pump to induce said liquid recirculation;
- utilizing said flow of pressurized liquid to power said jet type pump;
- and utilizing as said liquid feed pump a dynamic type pressure generating pump inherently providing a flow rate of said pressurized liquid flow to said boiler which varies inversely according to the liquid pressure differential across said pump.
A steam generating apparatus including a jet pump defining an inlet receiving a first flow of liquid from a low pressure source thereof, a high pressure inlet receiving a second flow of liquid from a pressurized steam drum of said apparatus, and an outlet discharging said first and said second flows together to a liquid feed pump, said liquid feed pump supplying said first and said second liquid flows pressurized to a boiler portion of said apparatus, said apparatus further including valve means controlling said second liquid flow in dependence upon the fluid pressure level within said steam drum.
A vapor pressure engine comprising:
- a boiler having an inlet and an outlet and being substantially filled with pressurized liquid, said boiler placing said pressurized liquid in heat exchange relation with a source of heat;
- a vapor drum communicating with said boiler outlet to receive a mixed flow of heated liquid and the saturated vapor resulting from boiling of said liquid, said heated liquid filling said vapor drum to a determinate level and the remainder to said steam drum being filled with said vapor;
- a super heater receiving a first flow of saturated vapor from said vapor drum, said super heater placing said first flow of vapor in heat exchange relation with said source of heat to convert said saturated vapor to superheated vapor;
- a fluid pressure operated motor receiving said first flow of superheated vapor and producing shaft power by expansion of said vapor to a relatively low pressure and temperature, said motor including a substantially continuously open fixed-area nozzle assembly controlling the fluid flow rate of said first flow directly according to the fluid pressure in said steam drum;
- a condenser receiving said first flow of vapor from said motor, said condenser placing said vapor in heat exchange relation with a heat absorber to condense said expanded vapor to liquid;
- a liquid well receiving said liquid from said condenser;
- a first jet pump receiving a second flow of liquid from said liquid well and a third flow of pressurized liquid from said vapor drum for admixture with said second liquid flow to increase the pressure thereof, said mixed second and third liquid flows forming a fourth pressurized liquid flow;
- control means in association with said first jet pump for controlling the flow rate of said second and third liquid flows as a function of fluid pressure in said vapor drum;
- a dynamic liquid pump having a substantially constant speed of operation and receiving said fourth liquid flow to increase the pressure thereof to a level greater than the fluid pressure in said vapor drum, the flow rate of said fourth liquid flow through said dynamic pump inherently being inversely related to the fluid pressure differential across the latter;
- and
- a second jet pump receiving a fifth flow of heated and pressurized liquid from said vapor drum and receiving said fourth liquid flow for admixture with said fifth liquid flow to increase the pressure thereof, said mixed fourth and fifth liquid flows forming a sixth liquid flow at a fluid pressure higher than that in said vapor drum, said second jet pump communicating said sixth liquid flow to said boiler inlet.
Dependencies are inferred from the claim text.