US 5,967,097 A · Once-through steam generator and a method of configuring a once-through steam generator

Abstract

The combustion chamber of a once-through steam generator is formed with walls of vertical tubes through which a flow medium flows from the bottom upwards. The tubes have a surface structure on their inner wall surfaces. Particularly favorable mass flow density m is established in the tubes at the load at which critical pressure prevails in the tubes according to the formula: ##EQU1## wherein q.sub.i is a heat flow density on an inner tube wall surface, T.sub.max is a maximum permissible material temperature of the tubes, T.sub.crit is a temperature of the flow medium at the critical pressure, .DELTA.T.sub.W is a temperature difference between the outer and inner wall surfaces of the tubes, and C is a constant.

Claims16

Dependent claims

A once-through steam generator, comprising:

a containing wall enclosing a combustion chamber, said containing wall being formed from a multiplicity of substantially vertical tubes connected to one another in a gas-tight manner;
said tubes being adapted to conduct therein a flow medium from a bottom upwards, and said tubes being formed with a surface structure on an inner wall thereof;
and
wherein a mass flow density m in said tubes, at a load at which a critical pressure prevails in said tubes, is defined by the following relationship:
##EQU8## where q.sub.i (kW/m.sup.2) is a heat flow density on an inside of said tubes, T.sub.max (.degree. C.) is a maximum permissible material temperature of said tubes, T.sub.crit (.degree. C.) is a temperature of the flow medium at the critical pressure (p.sub.crit) , .DELTA.T.sub.W (K) is a temperature difference between an outer wall and the inner wall of said tubes, and C.gtoreq.7.3.multidot.10.sup.-3 kWs/kgK is a constant.

2 more elements

A method of configuring a once-through steam generator with a combustion chamber surrounded by a containment wall composed of substantially vertical tubes connected to one another in a gastight manner, wherein the tubes are adapted to conduct therethrough an upwardly flowing flow medium during an operation of the once-through steam generator, the method which comprises:

forming the tubes with a surface structure on an inner wall surface thereof, and configuring the tubes such that, under an operational load at which a critical pressure p.sub.crit prevails in the tubes, a mass flow density m through the tubes is defined by:
##EQU12## where q.sub.i (kW/m.sup.2) is a heat flow density on an inside of the tubes, T.sub.max is a maximum permissible material temperature of the tubes, T.sub.crit is a temperature of the flow medium at the critical pressure, .DELTA.T.sub.W is a temperature difference between an outer wall and the inner wall of the tubes, and C.gtoreq.7.3.multidot.10.sup.-3 kWs/kgK is a constant.

Dependencies are inferred from the claim text.

Once-through steam generator and a method of configuring a once-through steam generator

Life of this patent

Once-through steam generator and a method of configuring a once-through steam generator

Life of this patent

Abstract

Claims16