CN102867113A - Method for determining feed water flow through deaerator inlet condensed water flow - Google Patents

Abstract

The invention relates to a method for determining a feed water flow through a deaerator inlet condensed water flow, which is simple and direct, and has the capability of obtaining an iterative calculation result automatically, quickly and directly. The method comprises the following steps: step 1, acquiring initial parameters of each high-pressure heater and deaerator; step 2, programming in an Excel electronic form, respectively calculating steam inlet enthalpy, water inlet enthalpy, water outlet enthalpy and draining enthalpy of each high-pressure heater and deaerator by using add-ins Water and steam property function; step 3, carrying out high heating balance calculation by using a supposed feed water flow so as to obtain a steam inlet flow of each high-pressure heater; step 4, carrying out deaerator heat balance and flow balance calculation so as to obtain a feed water flow value after passing through the high-pressure heater; step 5, taking the supposed feed water flow as the calculated feed water flow; and step 6, starting an iteration function of Excel, so that the calculation can be completed by the Excel.

Description

Determine the method for feedwater flow by oxygen-eliminating device entrance condensing water flow

Technical field

The present invention relates to determine by oxygen-eliminating device entrance condensing water flow in a kind of heating power calculating the method for feedwater flow.

Background technology

According to " ASME PTC6-2004 Turbine Performance Test rules ", feedwater flow draws by Gao Jia and oxygen-eliminating device heat Balance Calculation take oxygen-eliminating device entrance condensing water flow as benchmark, has used iterative computation in calculating.Usually, people adopt two kinds of methods to finish the iterative computation of feedwater flow in calculating, and first method is to use computer advanced language (such as C language or formula translation etc.), realizes iterative computation by programmed method; Second method is to utilize Excel to carry data analysis tool " goal seek " to finish.

These two kinds of methods have shortcoming separately: it is neither easy to programme with computer advanced language, also not directly perceived, needs simultaneously the heating power computing staff to possess stronger program capability and debugger capability; And utilize Excel to carry data analysis tool " goal seek " when finishing, and when the related calculating parameter of goal seek has arbitrary changing, need manually recomputating, the automaticity of program is lower.

Summary of the invention

Purpose of the present invention is exactly in order to address the above problem, provide a kind of easy, directly perceived, automatically recomputate pass through the method that oxygen-eliminating device entrance condensing water flow is determined feedwater flow.

For achieving the above object, the present invention adopts following technical scheme:

Determine the method for feedwater flow during a kind of heating power calculates by oxygen-eliminating device entrance condensing water flow, its step is:

The first step, measure respectively that each height adds and initial steam pressure, throttle (steam) temperature, leaving water temperature, inflow temperature, the drain temperature of oxygen-eliminating device, measure simultaneously oxygen-eliminating device incoming condensing water flow, desuperheating water of superheater flow, reheater desuperheating water flow and deaerator level and change equivalent flow;

Second step is programmed in the excel spreadsheet lattice, utilize to load grand " water and steam character character function " and tries to achieve respectively that each height adds and oxygen-eliminating device admission enthalpy, water inlet enthalpy, water outlet enthalpy, hydrophobic enthalpy;

In the 3rd step, the initial value of a feedwater flow of arbitrary assumption carries out the calculating of high heating balance with the feedwater flow of supposition, obtains the admission flow that each height adds;

The 4th step, the reheater desuperheating water flow of the oxygen-eliminating device entrance condensing water flow of the admission flow that each height that utilization calculates adds, actual measurement, the desuperheating water of superheater flow of actual measurement, actual measurement, deaerator level change equivalent flow and take the feedwater flow that adds by height as unknown quantity, carry out oxygen-eliminating device thermal equilibrium and flow equilibrium and calculate, calculate the feedwater flow value that adds by height;

The 5th step, the feedwater flow that equals to calculate with the feedwater flow of supposing.

The 6th goes on foot, and enables the iterative function of Excel, and Excel can finish calculating automatically, until the feedwater flow value that the feedwater flow value of supposition equals to calculate.

As follows by the programming process of Gao Jia and oxygen-eliminating device heat Balance Calculation feedwater flow take oxygen-eliminating device entrance condensing water flow as benchmark:

1, utilizes Excel to load grand " water and steam character character function " and try to achieve respectively that each height adds and oxygen-eliminating device admission enthalpy, water inlet enthalpy, water outlet enthalpy, hydrophobic enthalpy;

2, initial feedwater flow G _Fw1

3、G ₁＝G _fw1×(h _t1-h _t2)/(h _i1-h _ts1)；

4、G ₂＝(G _fw1×(h _t2-h _t3)-G ₁×(h _ts1-h _ts2))/(h _i2-h _ts2)；

5、 $G_n=(G_{\mathrm{fw}1}\×(h_{\mathrm{tn}}-h_{\mathrm{tn}+1})-\underset{i=1}{\overset{n-1}{\mathrm{\Σ}}}{G}_i\×(h_{\mathrm{tsn}}-h_{\mathrm{tsn}-1}))/(h_{\mathrm{in}}-h_{\mathrm{tsn}});$

6、

$G_{\mathrm{fw}2}=\frac{(G_{\mathrm{rhs}}+G_{\mathrm{shs}}-G_{\mathrm{da}}-G_{\mathrm{ns}}-\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{G}_i)\×h_{\mathrm{ic}}+\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{G}_i\×h_{\mathrm{tsn}}+G_{\mathrm{ns}}\×h_{\mathrm{tci}}-(G_{\mathrm{rhs}}+G_{\mathrm{shs}}-G_{\mathrm{da}})\×h_{\mathrm{tco}}}{h_{\mathrm{tco}}-h_{\mathrm{ic}}};$

7、G _fw1＝G _fw2；

G _Fw1---initial feedwater flow; G _Fw2---calculate feedwater flow; h _T1---the #1 height adds the water outlet enthalpy; h _T2---the #2 height adds the water outlet enthalpy; h _Tn---the N number high water outlet enthalpy that adds; h _Tn+1---N number high adding into the water enthalpy; h _Tco---oxygen-eliminating device water outlet enthalpy; h _Tci---oxygen-eliminating device water inlet enthalpy; h _Ts1---#1 HP heater drainage enthalpy; h _Ts2---#2 HP heater drainage enthalpy; h _Tsn---N HP heater drainage enthalpy; h _I1---the #1 height adds the admission enthalpy; h _I2---the #2 height adds the admission enthalpy; h _In---the N number high admission enthalpy that adds; h _Ic---oxygen-eliminating device admission enthalpy; G _Ns---oxygen-eliminating device entrance condensing water flow; G _Shs---the desuperheating water of superheater flow; G _Rhs---reheater desuperheating water flow; G _Da---deaerator level changes equivalent flow (water level just drops to); G ₁---the #1 height is added the steam flow amount; G ₂---the #2 height is added the steam flow amount; G _n---the N number high steam flow amount of adding.

The invention has the beneficial effects as follows: the excel spreadsheet lattice are office tools that people commonly use, and the heating power computing staff is very easy to left-hand seat; Utilize Excel to programme and determine the method for feedwater flow by oxygen-eliminating device entrance condensing water flow, the interface is easy, directly perceived, and can automatically, fast, directly obtain the iterative computation result.

Description of drawings

Fig. 1 is system architecture and measures and calculate synoptic diagram;

Below in conjunction with accompanying drawing and embodiment the present invention is done a progressive explanation.

Fig. 1 has provided the present invention determines the feedwater flow method by oxygen-eliminating device entrance condensing water flow system diagram, in order to calculate each well heater throttle flow, and then calculate feedwater flow according to oxygen-eliminating device entrance condensing water flow, measured that each height adds and initial steam pressure, throttle (steam) temperature, leaving water temperature, inflow temperature, the drain temperature of oxygen-eliminating device, measured simultaneously desuperheating water of superheater flow, reheater desuperheating water flow and deaerator level and changed equivalent flow.Each height adds admission enthalpy, hydrophobic enthalpy, water inlet enthalpy and water outlet enthalpy, and oxygen-eliminating device admission enthalpy, water inlet enthalpy and water outlet enthalpy load grand the realization by calling the water and steam character function that is embedded among the Excel.

Application example: take certain N330/C275-16.67/0.4/537/537 of factory type steam extraction and condensing formula steam turbine as example, its height add with oxygen-eliminating device therrmodynamic system structural drawing as shown in Figure 1, result of calculation sees the following form.

Claims (2)

1. determine the method for feedwater flow during a heating power calculates by oxygen-eliminating device entrance condensing water flow, it is characterized in that its step is:

The first step, measure respectively that each height adds and initial steam pressure, throttle (steam) temperature, leaving water temperature, inflow temperature, the drain temperature of oxygen-eliminating device, measure simultaneously oxygen-eliminating device incoming condensing water flow, desuperheating water of superheater flow, reheater desuperheating water flow and deaerator level and change equivalent flow;

Second step is programmed in the excel spreadsheet lattice, utilize to load grand " water and steam character character function " and tries to achieve respectively that each height adds and oxygen-eliminating device admission enthalpy, water inlet enthalpy, water outlet enthalpy, hydrophobic enthalpy;

In the 3rd step, the initial value of a feedwater flow of arbitrary assumption carries out the calculating of high heating balance with the feedwater flow of supposition, obtains the admission flow that each height adds;

The 4th step, the reheater desuperheating water flow of the oxygen-eliminating device entrance condensing water flow of the admission flow that each height that utilization calculates adds, actual measurement, the desuperheating water of superheater flow of actual measurement, actual measurement, deaerator level change equivalent flow and take the feedwater flow that adds by height as unknown quantity, carry out oxygen-eliminating device thermal equilibrium and flow equilibrium and calculate, calculate the feedwater flow value that adds by height;

The 5th step, the feedwater flow that equals to calculate with the feedwater flow of supposing;

The 6th goes on foot, and enables the iterative function of Excel, and Excel can finish calculating automatically, until the feedwater flow value that the feedwater flow value of supposition equals to calculate.

2. determine the method for feedwater flow during heating power as claimed in claim 1 calculates by oxygen-eliminating device entrance condensing water flow, it is characterized in that, described as follows by the programming process of Gao Jia and oxygen-eliminating device heat Balance Calculation feedwater flow take oxygen-eliminating device entrance condensing water flow as benchmark:

1) utilizes Excel to load grand " water and steam character character function " and try to achieve respectively that each height adds and oxygen-eliminating device admission enthalpy, water inlet enthalpy, water outlet enthalpy, hydrophobic enthalpy;

2) initial feedwater flow G _Fw1

3）G ₁＝G _fw1×(h _t1-h _t2)/(h _i1-h _ts1)；

4）G ₂＝(G _fw1×(h _t2-h _t3)-G ₁×(h _ts1-h _ts2))/(h _i2-h _ts2)；

$5)G_n=(G_{\mathrm{fw}1}\×(h_{\mathrm{tn}}-h_{\mathrm{tn}+1})-\underset{i=1}{\overset{n-1}{\mathrm{\Σ}}}{G}_i\×(h_{\mathrm{tsn}}-h_{\mathrm{tsn}-1}))/(h_{\mathrm{in}}-h_{\mathrm{tsn}});$

$6)G_{\mathrm{fw}2}=\frac{(G_{\mathrm{rhs}}+G_{\mathrm{shs}}-G_{\mathrm{da}}-G_{\mathrm{ns}}-\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{G}_i)\×h_{\mathrm{ic}}+\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{G}_i\×h_{\mathrm{tsn}}+G_{\mathrm{ns}}\×h_{\mathrm{tci}}-(G_{\mathrm{rhs}}+G_{\mathrm{shs}}-G_{\mathrm{da}})\×h_{\mathrm{tco}}}{h_{\mathrm{tco}}-h_{\mathrm{ic}}};$

7）G _fw1＝G _fw2；

G _Fw1---initial feedwater flow; G _Fw2---calculate feedwater flow; h _T1---the #1 height adds the water outlet enthalpy; h _T2---the #2 height adds the water outlet enthalpy; h _Tn---the N number high water outlet enthalpy that adds; h _Tn+1---N number high adding into the water enthalpy; h _Tco---oxygen-eliminating device water outlet enthalpy; h _Tci---oxygen-eliminating device water inlet enthalpy; h _Ts1---#1 HP heater drainage enthalpy; h _Ts2---#2 HP heater drainage enthalpy; h _Tsn---N HP heater drainage enthalpy; h _I1---the #1 height adds the admission enthalpy; h _I2---the #2 height adds the admission enthalpy; h _In---the N number high admission enthalpy that adds; h _Ic---oxygen-eliminating device admission enthalpy; G _Ns---oxygen-eliminating device entrance condensing water flow; G _Shs---the desuperheating water of superheater flow; G _Rhs---reheater desuperheating water flow; G _Da---deaerator level changes equivalent flow, and water level just drops to; G ₁---the #1 height is added the steam flow amount; G ₂---the #2 height is added the steam flow amount; G _n---the N number high steam flow amount of adding.

Images