OPERATION

Button Frame and Start Tab

This window is starting point for Operation Heat Balance calculation.

Operation Heat Balances show how the turbine cycle operates, when the turbine cycle is designed according to a Design Heat Balance.

The base Design Heat Balance is the lately run of the Design Heat Balance shown currently in "Design" combo box, regardless the lately run is List Updated or not.  Therefore, it is recommended to "Update List" and save the file of the base Design Heat Balance prior to Operation Heat Balance run.

 

Short Cut Icon Box ------------------------------------------------------------------------------------------------------------------

Design combo box

To show and select the list of Design Heat Balances that User is now working.

ES_Rankine save all the heat balances that User has worked in a file including Operation Heat Balances.

 

Oper.  combo box

To show and select the list of Operation Heat Balances that User is now working.

Operation Heat Balance shows how the turbine cycle works if the cycle is designed according to the Design Heat Balance, which the Operation Heat Balance is based on.   Heater Out of Operation heat balance is a kind of Operation Heat Balance.   A Design Heat Balance may have several Operation Heat Balances.

 

Button Frame -----------------------------------------------------------------------------------------------------------------------------

DESIGN button

To open DESIGN window.   When DESIGN window opens, the back ground color of DESIGN button changes to green, and the other buttons for Design Heat Balance are shown below.

 

OPERATION button

To open OPERATION window.   When OPERATION window opens, the back ground color of OPERATION button changes to green, and the other buttons for Operation Heat Balance are shown below.   

 

Run button

To execute calculation of Operation Heat Balance.   A progress bar is shown at the bottom of screen during calculation.

 

Graphic Output... button

To show a graphic output screen of Operation Heat Balance.

A Print button is provided in the graphic output screen, by which the graphic output can be printed out.

Graphic output screens are provided each for DESIGN and OPERATION separately, so that User can compare the results of both at sight.

 

Text Output... button

To show a text output screen of Operation Heat Balance.

Text output uses Note Pad software that is provided with Windows.   Note Pad execution file should be located in the file path of "C:\Windows\notepad.exe".

Text output is saved and overwritten automatically in the file name of "ES_Rankine_PLoad_e.txt" in the directory where ES_Rankine execution file is located.   Therefore, if User wants to save the text output, please save the text output file as another name by using file save function of Note Pad software.

 

Text output can be filed as Excel file of Microsoft Office software, by selecting a so-named option in the Text Output Option form which is shown by clicking the menu of "Option -> Text Output...".

The Excel file is saved and overwritten automatically in the file name of "ES_Rankine_PLoad_e_xls" in the directory where ES_Rankine execution file is located.   Therefore, if User wants to save the text output, please save the text output Excel file as another name by using file save function of Excel software.

Please note that the Excel file format saved by ES_Rankine may be different from a regular Excel file.   Therefore, after opening the file in Excel, please save it again as regular Excel format.

 

Add to List, Update List, Delete List buttons

Add to List to add the lately-executed operation heat balance to the "Oper." combo box list.

Update List to update the operation heat balance selected now in the "Oper." combo box with the lately-executed calculation results.

Delete List to delete the operation heat balance selected now in the "Oper." combo box.

 

Listing and file saving are independent in ES_Rankine.   Therefore, User has to save the file after listing Design(or Operation) heat balances in order to keep the data permanently.

Please refer to the relevant page of listing and file saving for details.

 

+ File Save check box

To save the list data into a file simultaneously when User clicks "Add to List", "Update List" or "Delete List".

Although this function has disadvantage of no chance to recover if there is a mistake in listing, recommended is the use of this function to secure the saving of data User made.

 

Start Tab --------------------------------------------------------------------------------------------------------------------------------

Title text box

To input the title of Operation Heat Balance.  The maximum length of the title is 70 characters.

 

Load Basis option buttons

.To select the load basis of Operation Heat Balance.   There are three options as below.

-

% Design Tbn. Gen. Power

 -> To input the load basis as the percent of Design Heat Balance generator output

-

Turbine Generator Output

 -> To input the load basis as the generator output itself.

-

Tbn. Inlet Flow (M1)

 -> To input the load basis as (HP) turbine inlet flow.

 

Turbine Inlet Pressure Control frame

To select and input Turbine Inlet Pressure Control method.

 

Constant Pressure option button

To select for maintaining the (HP) turbine inlet pressure of Operation Heat Balance to be same with that of Design Heat Balance.

 

Sliding Pressure option button

To select for having the (HP) turbine inlet pressure of Operation Heat Balance varied according to (HP) turbine inlet steam flow rate.   It simulates that the (HP) turbine inlet throttle valves are kept at a fixed opening position regardless of turbine output.

 

Throttle Valve Opening text box

To input throttle valve opening to be kept in sliding pressure operation.

For pure sliding, please input "100"% so that (HP) turbine inlet steam pressure starts to decrease as soon as turbine output decreases from Design Heat Balance output.

In case of modified sliding pressure operation, please input less than "100"% so that Design Heat Balance pressure is maintained down to a part load, and then starts to decrease after the part load.   For example, if User inputs "85"%, Design Heat Balance pressure is maintained down to approximately 90% load, and then starts to decrease at 90% load and below.   The modified sliding pressure operation is used in Super-critical pressure power plants in order to meet Grid Frequency Response requirements.

 

Minimum Throttle Pressure text box

To input the minimum throttle pressure to be maintained regardless of load in sliding pressure operation.   Input should be percent of Design Heat Balance pressure.

If (HP) turbine inlet pressure drops below the minimum throttle pressure in sliding pressure operation, the minimum throttle pressure is maintained.

 

Tbn. Inlet Temp.(T1) / Same with Design text box and check box

To select or input (HP) turbine inlet steam temperature.   If "Same with Desine" is checked, the (HP) turbine inlet steam temperature of Design Heat Balance is maintained.

 

Reheat Steam Temp. / Same with Design text box and check box

To select or input reheat turbine inlet steam temperature.   If "Same with Desine" is checked, the reheat turbine inlet steam temperature of Design Heat Balance is maintained.

 

Stop BFP Turbine Operation check box

To select stop of BFP Turbine Operation even though Turbine Driven BFP is selected in Design Heat Balance.   If this check box is checked, BFP driving steam turbine is simulated as stopped in Operation Heat Balance and BFP is driven by stand-by electric motor.

 

Variable Speed BFP check box

To select BFP as driven by a variable speed driver, such as VVF electric motor or variable speed coupling.

If Turbine Driven BFP is selected in Design Heat Balance, this check box is checked and inactivated.

In case of variable speed BFP, the discharge pressure of BFP at Operation Heat Balance(= Part Load)is calculated as below.

 

P_BFPDisPR_PLoad = P_HPTbn_PLoad x Pct_BFPDisPR / 100

wherein :

 

- P_BFPDisPR_PLoad

: BFP discharge pressure at part load

- P_HPTbn_PLoad

: (HP) turbine inlet steam pressure at part load

- Pct_BFPDisPR

: BFP Discharge Press % input in "Pump" tab of DESIGN window

 

In case of constant speed BFP, i.e. "Variable Speed BFP" check box unchecked, the discharge pressure of BFP at part load is calculated as below.

P_BFPDisPR_PLoad = P_HPTbn_Design x Pct_BFPDisPR / 100 x PLoad_H-Q_Pct_Builtin / 100

wherein :

 

- P_BFPDisPR_PLoad

: BFP discharge pressure at part load

- P_HPTbn_Design

: (HP) turbine inlet steam pressure at Design Heat Balance

- Pct_BFPDisPR

: BFP Discharge Press % input in "Pump" tab of DESIGN window

- PLoad_H-Q_Pct_Builtin

: Head rise % at  part load according to built-in standard pump H-Q Curve

 

For BFP pump efficiency, the BFP Efficiency input value for Design Heat Balance is used as it is in case of Variable Speed BFP.   In case of Constant Speed BFP, the efficiency according to built-in standard pump efficiency is used.

 


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