CN102324205B - Experimentally runnable pressurized water reactor and steam generator simulation model thereof - Google Patents

Abstract

The invention belongs to the technical field of nuclear power and particularly relates to a dynamic simulation model for a pressurized water reactor and a steam generator thereof, which can be used for conducting teaching experiments and simulating the normal operation and the loss-of-coolant accident of the pressurized water reactor. The dynamic simulation model consists of the steam generator, a pressure vessel, a pressure stabilizer, pipelines, a measurement system and a heating element. The lower head of the steam generator is divided into a water inlet chamber and a water outlet chamber through a baffle, wherein the water inlet chamber is connected with the upper part of the pressure vessel through a water inlet pipeline and the water outlet chamber is connected with the lower part of the pressure vessel through a water outlet pipeline. The water inlet pipeline is connected with the pressure stabilizer by arranging a bypass on the water inlet pipeline. The top of the pressure stabilizer is respectively connected with the tops of four liquid column manometers through the pipelines. The bottoms of the four liquid column manometers are respectively connected with four outlets which are evenly distributed on the side wall of the pressure vessel along the height direction. The model has the advantages that the structure is simple, the implementation is easy, the model not only is safe and reliable, but also can be operated by students in person, the perceptual and rational knowledge of the students to a nuclear reactor is improved and the goals of teaching and conducting scientific researches are achieved.

Description

Can test the presurized water reactor and the steam generator dynamic simulation model thereof of operation

Technical field

The invention belongs to the nuclear power energy technology field, the particularly a kind of presurized water reactor and steam generator dynamic simulation model thereof that can carry out education experiment, the normal operation of simulation presurized water reactor and loss of-coolant accident (LOCA).

Background technology

Nuclear power station is a great system engineering, because the closure of nuclear island, also unlikely see concrete core structure even if arrived nuclear power plant, this has just caused the student of nuclear power specialty and its object of learning seriously to separate, and a lot of students did not meet nuclear reactor up to graduation yet.At present, the demonstrating model that nuclear power teaching is used to demonstrate the nuclear reactor principle mostly is the static model that plastics or foam are made, be merely able to show that equipment constitutes in the nuclear island, but can not demonstrate the ANALYSIS OF COOLANT FLOW process in the loop, one, the diabatic process of secondary circuit, the production process of steam in the steam generator, and process is flooded in the reactor core dehydration again.

Summary of the invention

The present invention is directed to the shortcoming of existing pressurized-water reactor nuclear power plant static model, a kind of presurized water reactor and steam generator dynamic simulation model thereof of testing operation is provided.

The technical solution used in the present invention is:

Be made of steam generator, pressure vessel, voltage stabilizer, pipeline, measuring system and heating element, it is characterized in that, the low head of steam generator adopts semisphere, is divided into intake chamber and water-supplying chamber by dividing plate; Described intake chamber is connected with the top of pressure vessel by inlet pipeline, and described water-supplying chamber is connected with the bottom of pressure vessel by outlet pipeline; On described inlet pipeline,, be connected with voltage stabilizer by bypass is set; The top of voltage stabilizer is connected with the top of 4 liquid column gauges respectively by pipeline, and the bottom of 4 liquid column gauges is connected with equally distributed 4 outlets of pressure vessel sidewall upper edge short transverse respectively; This model adopts Natural Circulation, and the electrically heated rod in the pressure vessel heats the cooling medium in the loop, and cooling medium is passed to the working medium of secondary circuit to heat by steam generator, makes the water generates steam of secondary circuit.

Described steam generator, voltage stabilizer, pressure vessel and pipeline are made by glass.

The cooling medium in a described loop and the working medium in the secondary circuit are water.

In the described pressure vessel, with electrically heated rod simulation fuel assembly for nuclear reactor, and the adjustable power of described electrically heated rod.

On the described steam generator sidewall, on the pressure vessel inside, inlet pipeline, thermopair all is set on the outlet pipeline.

The manual adjustments angle valve is set on the described outlet pipeline, the leakage valve is set in the bypass of outlet pipeline.

Cyclic water tank is set, and the outlet of cyclic water tank is connected with the water inlet of a loop and secondary circuit respectively; Between the outlet of cyclic water tank and inlet, jetting pump is set, and an outlet of jetting pump enters the mouth with the top of steam generator and is connected; By the negative pressure that jetting pump produces, make the working medium in the secondary circuit be lower than 100 ℃ of boilings down.

The invention has the beneficial effects as follows: for strengthening nuclear power Major and related work personnel understanding PWR nuclear power plant nuclear island part critical piece, and one, the understanding of the diabatic process between the secondary circuit, cooperate teaching by setting up the dynamically transparent mock-up reactor, electrically heated rod simulation fuel assembly for nuclear reactor with scalable power, adopt pipelines such as core pressure vessel that heat-resisting withstand voltage glass container and pipeline come mock-up reactor, voltage stabilizer, steam generator, heat transfer U-shaped pipe, be equipped with monitoring sensor and electrical heating regulating device simultaneously.This model can be finished four kinds of experimental teachings: the hot arm flow velocity experiment in a loop; The experiment of pressure vessel void fraction; The experiment of electrically heated rod surface coefficient of heat transfer; The process lecture experiment is flooded in the reactor core dehydration again.This model structure is simple, and cost is low, and is easy to implement, both safe and reliable, can allow the student operate in person again, thereby strengthens perception and the rational knowledge of student to nuclear reactor, reaches teaching, scientific research purpose.

Description of drawings

Fig. 1 is presurized water reactor and the steam generator dynamic simulation structure of models figure thereof that tests operation of the present invention;

Fig. 2 is a line arrangement system diagram of the present invention;

Fig. 3 is a U-shaped pipe Pareto diagram.

Number in the figure:

The 1-steam generator; The 2-voltage stabilizer; The 3-pressure vessel; 4-steam generator water inlet; 5-steam generator water delivering orifice; 6-the 8th thermopair; 7-one loop water inlet; 8-manual adjustments angle valve; The 9-leak valve; 10-secondary circuit pressure gauge; 11-the 6th thermopair; 12-the 7th thermopair; 13-one circuit pressure meter; The 14-safety valve; 15-ink syringe; 16-the 5th thermopair; 17-the 4th thermopair; The 18-three thermocouple; 19-second thermopair; 20-first thermopair; 21-first liquid column gauge; 22-second liquid column gauge; 23-the 3rd liquid column gauge; 24-the 4th liquid column gauge; The 25-jetting pump; The outlet of 26-cyclic water tank; 27-steam generator top; 28-cyclic water tank inlet; 29-secondary circuit water inlet.

Embodiment

The invention provides a kind of presurized water reactor and steam generator dynamic simulation model thereof of testing operation, the present invention will be further described below in conjunction with accompanying drawing and concrete experimental procedure and principle.

As shown in Figure 1, according to the presurized water reactor principle, this experimental apparatus is by steam generator, voltage stabilizer, three major equipments of pressure vessel, and pipeline, valve, measuring system and heating element constitute.

The low head of steam generator 1 adopts semisphere, is divided into intake chamber and water-supplying chamber by dividing plate, and 8 parallel U-shaped pipes wherein in parallel have increased heat interchanging area, thus the heat transfer efficiency that improves; Described intake chamber is connected by the top of inlet pipeline with pressure vessel 3, and described water-supplying chamber is connected by the bottom of outlet pipeline with pressure vessel 3; On described outlet pipeline,, be connected with voltage stabilizer 2 by bypass is set; The top of voltage stabilizer 2 is connected with the top of first liquid column gauge 21, second liquid column gauge 22, the 3rd liquid column gauge 23, the 4th liquid column gauge 24 respectively by pipeline, and the bottom of 4 liquid column gauges is connected with equally distributed 4 outlets of pressure vessel sidewall upper edge short transverse respectively; In the pressure vessel 3, the electrically heated rod of 7 scalable power is set, every peak power is 250W, and the simulation fuel assembly for nuclear reactor is used for heating the cooling medium in the loop.Steam generator 1 and wherein U-shaped pipe, voltage stabilizer 2, pressure vessel 3 and pipeline are all made by glass.Consider that glass container can not be high pressure resistant, so this experimental apparatus do not have main circulation pump, adopt Natural Circulation, with the working medium of water as the cooling medium and the secondary circuit in a loop.

A safety valve 14 and a circuit pressure meter 13 are set on the voltage stabilizer 2, and the pressure when a loop surpasses safe pressure, then safety valve releasing pressure automatically.One circuit pressure meter 10 is set on the steam generator 1.

Manual adjustments angle valve 8 is set on the outlet pipeline, in the bypass of outlet pipeline, is provided with and reveals valve 9.

Measuring system comprises: near the hot arm pressure vessel 3 outlets ink syringe 15 is set, can measures the flow velocity of cooling medium at hot arm by the distance that ink in the record certain hour flows; Eight thermopairs are set in the model altogether, be distributed in respectively: the three thermocouple 18, second thermopair 19 and first thermopair 20 that from top to bottom set gradually on the electrically heated rod of pressure vessel 3 inside, the 4th thermopair 17 of pressure vessel 3 inflow points, the 5th thermopair 16 in pressure vessel 3 exits, the 6th thermopair 11 on steam generator 1 chamber wall, the 7th thermopair 12 of steam generator 1 inflow point, the 8th thermopair 6 in steam generator 1 exit; One circuit pressure meter 13 and secondary circuit pressure gauge 10 are installed in voltage stabilizer wall and steam generator wall respectively, are used for measuring one, the first pressing of secondary circuit.On the wall vertical height of pressure vessel 3, be uniform-distribution with four pressure tap that are connected with liquid column gauge, be used for the void fraction α of estimated pressure container section.

As shown in Figure 2, cyclic water tank is set, cyclic water tank outlet 26 is connected with the water inlet 29 of a loop water inlet 7, secondary circuit respectively; Between cyclic water tank outlet 26 and cyclic water tank inlet 28, jetting pump 25 is set, and an outlet of jetting pump 25 is connected with steam generator top inlet 27; By the negative pressure that jetting pump 25 produces, make the working medium in the secondary circuit be lower than 100 ℃ of boilings down.

Cooling medium flows in a loop by Natural Circulation, enters the intake chamber in steam generator 1 low head, enter then in the U-shaped pipe in parallel, by tube wall the heat transferred secondary circuit.Because in the loop be normal pressure, temperature can not surpass 100 ℃, so the secondary circuit temperature can be above 100 ℃ yet.For making the water generates saturated vapour in the secondary circuit, connect jetting pump at the top of steam generator.The negative pressure that produces by jetting pump reduces the secondary side pressure of evaporator, thereby the boiling point of water is reduced, and is being lower than the water boiling that makes steam generator secondary side under 100 ℃ the temperature.

Use the experimental procedure of this model as follows:

(1) determines each valve state of experimental facilities: the valve opening at pressure vessel 3 tops; Voltage stabilizer 2 blowdown valves are opened; Manual adjustments angle valve 8 is closed; Leak valve 9 is opened.

(2) to a loop water filling, require cooling medium with certain velocity flow through a loop, be as the criterion with the bubble that can wash out top in 1 li U-shaped pipe of steam generator.

(3) open each thermopair, display shows the temperature of three thermocouple 18.

(4) open water delivering orifice on the voltage stabilizer 2, so that the water level of 2 li of voltage stabilizers reaches suitable height.

(5) rap the glass tube of four liquid column gauges, remove bubble wherein, because the valve opening on voltage stabilizer 2 tops, and be connected, so the air of the inside all is an atmospheric pressure with four liquid column gauges.The initial water level of four liquid column gauges should be contour.

The initial temperature of (5) first thermopairs 20, second thermopair 19, three thermocouple 18, the 4th thermopair 17 and the 5th thermopair 16 should be the same.

(6) closeall valve is only opened manual adjustments angle valve 8.

(7) general power of electrically heated rod in the pressure vessel 3 is brought up to 500W, open jetting pump 25.

(8) wait for that three thermocouple 18 reaches balance, the water boiling that steam generator is 1 li, if water level drops to below the U-shaped pipe, timely supplementing water.

(9) temperature of eight thermopairs of record, the water level of four liquid column gauges and voltage stabilizer 2, the pressure of a circuit pressure meter 13 and secondary circuit pressure gauge 10, the hot arc flow rate of water flow also has the phenomenon of steam generator and pressure vessel.

(10) general power of electrically heated rod in the pressure vessel 3 is transferred to 700W, 900W and 1200W repeat above step.

(11) the power set to zero, close jetting pump.

The experimental principle of this model is:

Experiment one: ask the hot arc flow velocity

Method is 1.: the dyestuff velocity determination

$v=\frac{l}{t};$

Wherein: t is the time of dyestuff through unit distance

Method is 2.: Bernoulli equation

For the closed-loop path of a Natural Circulation, the fluid buoyancy of loop each several part i equals the droop loss that it causes because of friction.Therefore Bernoulli equation can be expressed as:

$\underset{i}{\mathrm{\Σ}}{\left(\underset{z_i}{\overset{z_i-1}{\∫}}\mathrm{\ρgdz}\right)}_i=\underset{i}{\mathrm{\Σ}}{\left({\mathrm{\ρ}}_0{f}_i\frac{L_i}{D_i}\frac{U_i^2}{2}\right)}_i+\underset{i}{\mathrm{\Σ}}{\left({\mathrm{\ρ}}_{0}K\frac{U_i^2}{2}\right)}_i;$

ρ ₀Be the average density of fluid, g is a local gravitational acceleration, and z is the vertical height of fluid, and f is the friction factor of runner, and K is the local losses coefficient, L _iFor causing the flow channel length of linear loss, D _iBe hydraulic diameter, U _iMean flow rate for the i part.

For the runner that xsect changes, should consider to introduce the invariant of runner, i.e. flow Q.Q=U _iA _iWith Bring into, can be written as:

$\underset{i}{\mathrm{\Σ}}{\left(\underset{z_i}{\overset{z_i-1}{\∫}}\mathrm{\ρgdz}\right)}_i=\underset{i}{\mathrm{\Σ}}{\left({\mathrm{\ρ}}_0{f}_i\frac{{8L}_i{Q}^2}{{\mathrm{\π}}^2{D}_i^5}\right)}_i+\underset{i}{\mathrm{\Σ}}{\left({\mathrm{\ρ}}_{0}K\frac{8Q^2}{{\mathrm{\π}}^2{D}_i^1}\right)}_i;$

The buoyancy of this model Natural Circulation can be drawn by following Equation for Calculating:

$\underset{i}{\mathrm{\Σ}}\left(\underset{z_i}{\overset{z_i-1}{\∫}}\mathrm{\ρgdz}\right)={\mathrm{\ρ}}_{\mathrm{CL}}g{H}_{\mathrm{DC}}-\underset{0}{\overset{H_{\mathrm{DC}}}{\∫}}{\mathrm{\ρ}}_{\mathrm{core}}\mathrm{gdz}=g{H}_{\mathrm{DC}}({\mathrm{\ρ}}_{\mathrm{CL}}-{\stackrel{\‾}{\mathrm{\ρ}}}_{\mathrm{core}}).$

ρ _CLBe the coolant density of cold section of experimental apparatus, H _DCBe the vertical height of cooling medium decline passway (downcomer), ρ _CoreBe the coolant density of each height of reactor pressure vessel,

Average density for the pressure vessel cooling medium.Exactly because the fluid of the system that the density difference of cooling medium causes flows, and the density difference of cooling medium can be estimated by local temperature: Δ ρ=-β Δ T ρ ₀β is the thermal expansivity of cooling medium, and the coefficient of volumetric expansion of water is 3.6 * 10 in the time of 40 ℃ ^-4℃ ^-1Δ T=T _CL-T _Core≈ T _CL-(T _HL+ T _CL)/2, T _HLBe the hot arc temperature.More than can draw the buoyancy size.

The pipeline Reynolds number is:

${\mathrm{Re}}_D=\frac{{\mathrm{\ρ}}_0{U}_i{D}_i}{\mathrm{\μ}}\≅\frac{{\stackrel{\‾}{\mathrm{\ρ}}}_{\mathrm{core}}{D}_i}{\mathrm{\μ}}{U}_i.$

U _iBe the flow velocity of tube-cooled agent, get maximal value 0.1m/s.D _iBe pipe diameter, be 0.019m.

${\mathrm{Re}}_D=\frac{{\stackrel{\‾}{\mathrm{\ρ}}}_{\mathrm{core}}{D}_i}{\mathrm{\μ}}{U}_i\≤\frac{\left({10}^3\right)(2\×{10}^{-2})\left({10}^{-1}\right)}{{10}^{-3}}=2000,$

So ducted flowing is laminar flow: f=64/Re _D

$\underset{i}{\mathrm{\Σ}}{\left({\mathrm{\ρ}}_0{f}_i\frac{L_i}{D_i}\frac{U_i^2}{2}\right)}_i+\underset{i}{\mathrm{\Σ}}{\left(K\frac{U_i^2}{2}\right)}_i$

$={\mathrm{\ρ}}_0[\underset{i}{\mathrm{\Σ}}{\left(\frac{64\mathrm{\μ}}{{\mathrm{\ρ}}_0{U}_i{D}_i}\frac{L_i}{D_i}\frac{U_i^2}{2}\right)}_i+\underset{i}{\mathrm{\Σ}}{\left(K\frac{U_i^2}{2}\right)}_i]$

$=\underset{i}{\mathrm{\Σ}}{\left({\mathrm{\ρ}}_{0}K\frac{U_i^2}{2}\right)}_i+\underset{i}{\mathrm{\Σ}}{\left(\frac{32\mathrm{\μ}{L}_i{U}_i}{D_i^2}\right)}_i$

Can calculate U by buoyancy again _i

Method is 3.: conservation of energy

P=ρ _HA _TubeUC _p(T _H-T _C) A wherein _TubeFor cross-section of pipeline amasss, C _pFor specific heat of water holds, T _H-T _CBe the cold and hot section temperature difference.

Experiment two: the void fraction α of estimation RPV

Can know pressure distribution on the pressure vessel vertical direction by the reading of four liquid column gauges, wherein the pressure of ordering of the i on the short transverse is:

P _i＝P _ref+ρ _wg(H _i-H _io)，

P wherein _RefBe system's first pressing, can read ρ by the pressure gauge reading on the voltage stabilizer that is attached thereto _wBe the density of cooling medium under the room temperature, H _IoBe the distance of i point apart from the pressure vessel bottom, H _iBe the height of water level in the liquid column gauge.

Void fraction can be calculated by following two formula:

P _j-P _i＝ΔP _loss+ρ _mixg(H _io-H _jo)≈ρ _mixg(H _io-H _jo)，

ρ _mix＝(1-α)ρ _w+αρ _s，

Δ P wherein _LossBe the sky mobile energy loss of ducking in drink, ρ _MixBe the hybrid density of two-phase flow, ρ _sDensity for water vapor.

P _j-P _i＝ρ _wg(H _j-H _jo)-ρ _wg(H _i-H _io)＝ρ _wg[(H _j-H _i)-(H _jo-H _io)]，

ρ _mixg(H _jo-H _io)＝ρ _wg[(H _j-H _i)-(H _jo-H _io)]，

${\mathrm{\ρ}}_{\mathrm{mix}}={\mathrm{\ρ}}_w\frac{(H_j-H_i)-(H_{\mathrm{jo}}-H_{\mathrm{io}})}{H_{\mathrm{io}}-H_{\mathrm{jo}}}={\mathrm{\ρ}}_w[1-\frac{H_j-H_i}{H_{\mathrm{jo}}-H_{\mathrm{io}}}],$

Can get void fraction α is:

$\mathrm{\α}=\frac{{\mathrm{\ρ}}_w}{{\mathrm{\ρ}}_w-{\mathrm{\ρ}}_s}\frac{H_j-H_i}{H_{\mathrm{jo}}-H_{\mathrm{io}}}.$

Analyze:

If H _j=H _i, ρ then _Mix=ρ _w, be the single-phase water state;

If H _j＞H _i, ρ then _Mix＜ρ _w, be the two-phase flow state;

If H _j＜H _i, ρ then _Mix＞ρ _w, this situation can not appear.

Experiment three: the surface film thermal conductance of asking heating rod

Method is 1.: conservation of energy

The surface coefficient of heat transfer of heating rod can be used following formulate:

$\frac{P}{A_{\mathrm{rods}}}=h(T_w-T_f),$

Wherein P is the heating power sum of 7 electrically heated rods, A _RodsBe 7 surface areas that electrically heated rod is total, T _wBe the surface temperature of electrically heated rod, T _fBe water temperature.

Method is 2.: the Nusselt number method

$\mathrm{Nu}=0.023{\mathrm{Re}}^{0.8}{\mathrm{Pr}}^{0.4}=\frac{h{D}_h}{k}$

Wherein h is the surface film thermal conductance of electrically heated rod, and k is a coefficient of heat conductivity.

Claims (4)

1. can test the presurized water reactor and the steam generator dynamic simulation model thereof of operation, constitute by steam generator (1), pressure vessel (3), voltage stabilizer (2), pipeline, measuring system and heating element, it is characterized in that, the low head of steam generator (1) adopts semisphere, is divided into intake chamber and water-supplying chamber by dividing plate; Described intake chamber is connected by the top of inlet pipeline with pressure vessel (3), and described water-supplying chamber is connected by the bottom of outlet pipeline with pressure vessel (3); On described inlet pipeline,, be connected with voltage stabilizer (2) by bypass is set; The top of voltage stabilizer (2) is connected with the top of 4 liquid column gauges respectively by pipeline, and the bottom of 4 liquid column gauges is connected with equally distributed 4 outlets of pressure vessel sidewall upper edge short transverse respectively;

Described steam generator (1), voltage stabilizer (2), pressure vessel (3) and pipeline are made by glass;

In the described pressure vessel (3), with electrically heated rod simulation fuel assembly for nuclear reactor, and the adjustable power of described electrically heated rod;

Described measuring system comprises: near the hot arm pressure vessel (3) outlet ink syringe (15) is set, can measures the flow velocity of cooling medium at hot arm by the distance that ink in the record certain hour flows; Eight thermopairs are set in the model altogether, be distributed in respectively: the three thermocouple (18), second thermopair (19) and first thermopair (20) that from top to bottom set gradually on the electrically heated rod of pressure vessel (3) inside, the 4th thermopair (17) of pressure vessel (3) inflow point, the 5th thermopair (16) in pressure vessel (3) exit, the 6th thermopair (11) on steam generator (1) chamber wall, the 7th thermopair (12) of steam generator (1) inflow point, the 8th thermopair (6) in steam generator (1) exit; One circuit pressure meter (13) and secondary circuit pressure gauge (10) are installed in voltage stabilizer (2) wall and steam generator (1) wall respectively, are used for measuring one, the first pressing of secondary circuit;

This model adopts Natural Circulation, and the electrically heated rod in the pressure vessel heats the cooling medium in the loop, and cooling medium is passed to the working medium of secondary circuit to heat by steam generator, makes the water generates steam of secondary circuit.

2. presurized water reactor and steam generator dynamic simulation model thereof of testing operation according to claim 1 is characterized in that the cooling medium in a described loop and the working medium in the secondary circuit are water.

3. presurized water reactor and steam generator dynamic simulation model thereof of testing operation according to claim 1 is characterized in that, manual adjustments angle valve (8) is set on the described outlet pipeline, is provided with to reveal valve (9) in the bypass of outlet pipeline.

4. presurized water reactor and steam generator dynamic simulation model thereof of testing operation according to claim 1 is characterized in that, cyclic water tank is set, and the outlet of cyclic water tank is connected with the water inlet of a loop and secondary circuit respectively; Between the outlet of cyclic water tank and inlet, jetting pump is set, and an outlet of jetting pump enters the mouth with the top of steam generator (1) and is connected; By the negative pressure that jetting pump produces, make the working medium in the secondary circuit be lower than 100 ℃ of boilings down.

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