PhilOos
Mechanical
- Oct 4, 2006
- 28
Hi,
I've build a dynamic two-phase flow model (with heat-transfer) in order to simulate the process inside a "Main Steam Warming Line" for a power station. The aim of the exercise is to determine the characteristics of the throttling valve at the downstream side of the line. According to standard the rate of change during cold startup is in the order of 3 [deg C/min].
The problem is as follows: Initially the main steam line and warming line is filled with air at 25 [deg C]. At a steam temperature of 130 [deg C], the isolation valve opens and steam starts to flow into the main steam line. But as soon as I introduce steam to the cold pipe it condenses against the cold wall and an increase in the wall temperature of almost 200 [deg C/min] is observed. This phenomenon only prevails for a short period (about 5 minute). Does this happen in normal practice?
If it does, why do I then need to consider a throttling valve?
Kind regards
Philip Oosthuizen
Company info:
SteinMuller Engineering Services
I've build a dynamic two-phase flow model (with heat-transfer) in order to simulate the process inside a "Main Steam Warming Line" for a power station. The aim of the exercise is to determine the characteristics of the throttling valve at the downstream side of the line. According to standard the rate of change during cold startup is in the order of 3 [deg C/min].
The problem is as follows: Initially the main steam line and warming line is filled with air at 25 [deg C]. At a steam temperature of 130 [deg C], the isolation valve opens and steam starts to flow into the main steam line. But as soon as I introduce steam to the cold pipe it condenses against the cold wall and an increase in the wall temperature of almost 200 [deg C/min] is observed. This phenomenon only prevails for a short period (about 5 minute). Does this happen in normal practice?
If it does, why do I then need to consider a throttling valve?
Kind regards
Philip Oosthuizen
Company info:
SteinMuller Engineering Services
