Condenser Evacuation Line Reduces Startup Time
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Solution Overview
Problem
Existing water/steam cycle configurations in thermal power plants face inefficiencies due to suction side pressure losses and prolonged condenser evacuation times during start-up, primarily because of the use of expensive and unreliable auxiliary steam and electric vacuum pumps.
Innovation Solution
Incorporating an additional evacuation line with a motorized isolating valve that connects the external ejector/vacuum pump directly to the condenser shell, allowing for efficient evacuation without auxiliary steam, thereby minimizing pressure losses and condenser evacuation time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If auxiliary steam and electric vacuum pumps are used to evacuate the condenser, then the condenser can be evacuated, but the system becomes expensive and unreliable
Solution Approach 1:
The ejector vacuum pump uses its own exhaust steam to create the vacuum in the condenser, eliminating the need for separate auxiliary steam systems and electric vacuum pumps. The system serves itself by utilizing its operational byproduct (exhaust steam) to perform the evacuation function.
Solution Approach 2:
The ejector vacuum pump performs multiple functions: it condenses steam and simultaneously creates the vacuum in the condenser using its exhaust steam. This multi-functionality eliminates the need for separate dedicated evacuation equipment.
2Device complexity
If no auxiliary components are used, then the system remains simple, but suction side pressure losses substantially increase condenser evacuation time
Solution Approach 1:
The ejector vacuum pump is pre-positioned and connected to the condenser, ready to immediately utilize its exhaust steam for evacuation as soon as it begins operation. This preliminary preparation eliminates delays associated with starting separate evacuation systems.
Solution Approach 2:
The exhaust steam from the ejector vacuum pump continuously serves dual purposes: maintaining the vacuum and facilitating rapid evacuation. This continuous utilization of exhaust steam eliminates idle time and maintains efficient evacuation throughout the startup process.
3Reliability
If air coolers with small orifices are used, then gas separation is achieved, but flow resistance substantially increases pressure loss
Solution Approach 1:
The harmful flow resistance effect of small orifices is extracted and removed from the system. Instead of using restricted orifices for gas separation, the invention uses open drift-type structures that allow free flow while still achieving effective gas-steam separation through condensation and gravity.
4Reliability
If internal piping is added to connect air coolers to vacuum pump, then gas evacuation is enabled, but additional restrictions increase pressure loss
Solution Approach 1:
The harmful internal piping with its inherent restrictions is extracted and removed from the system. The invention achieves gas evacuation without requiring complex internal piping networks, using instead a direct connection from the condenser to the ejector vacuum pump.
Solution Approach 2:
The functions of gas separation and gas evacuation are merged into a simpler configuration where the ejector vacuum pump directly handles both condensation and vacuum creation, eliminating the need for separate air cooler assemblies and their associated piping.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution reduces condenser evacuation time by 33% and eliminates the need for expensive auxiliary steam, maintaining standard condenser configuration without additional costs, thus enhancing the performance and efficiency of the water/steam cycle during start-up.
Implementation Method 1
an external ejector/vacuum pump 25...pumping them down
Implementation Method 2
the pressure mainly has to two causes...substantial pressure drop Δp of app. 25% from the condenser 13 to the ejector/vacuum pump 25
Implementation Method 3
the water cooled condenser 13...converted back into feedwater by means of the water cooled condenser 13
Implementation Method 4
The condensed steam is collected in a hot well 24
Implementation Method 5
feedwater pump 15...pumped to the steam generator 11 by means of the feedwater pump 15
Data Source
AI summary
A water/steam cycle includes a steam generator, a steam turbine, a water cooled condenser and a feedwater pump. The condenser includes within a condenser shell at least one tube bundle with an internal air cooler, which is connected to an external ejector/vacuum pump by means of a suction line. In order to reduce the condenser evacuation time at the start-up of the water/steam cycle without using auxiliary steam, an additional evacuation line with a motorized isolating valve connects the external ejector/vacuum pump with the condenser shell. The action of the isolating valve is controlled by means of a control.