CN103795190A - Filter-type ventilation system of large lamp bulb tubular pump unit and determining method of economical efficiency thereof - Google Patents

Abstract

The invention discloses a filter-type ventilation system of a large lamp bulb tubular pump unit and a determining method of the economical efficiency of the filter-type ventilation system of the large lamp bulb tubular pump unit. The filter-type ventilation system comprises a ventilator, a matched motor of the ventilator, the lamp bulb tubular pump unit, an air inlet pipe, an air outlet pipe, and a lamp bulb tubular pump unit motor inside a lamp bulb shell, wherein the ventilator is arranged outside the tubular pump unit and is connected with an air inlet, corresponding to the air inlet end of the lamp bulb tubular pump unit motor, of the lamp bulb shell through the air inlet pipe; an air outlet, corresponding to the air outlet end of the lamp bulb tubular pump unit motor, of the lamp bulb shell is connected with the air outlet pipe to be outside a station building. Filter materials are arranged at the air inlet of the ventilator, and pressure difference measurement devices are arranged in front and at back of the filter materials. As the filter materials are arranged at the air inlet of the ventilator, sucked air is filtered, the aim of purifying the tubular pump unit to achieve ventilation cooling is achieved, the ventilation cooling effect of the motor is improved, the heavy maintenance period is prolonged, the heavy maintenance expenses and ventilation operation expenses are saved, the additionally arranged filter materials are low in cost, replacement is convenient, and the ventilation system has good comprehensive economical performance.

Description

Large-scale bulb through-flow pump assembly filtering type ventilating system and economy thereof are determined method

Technical field

The present invention relates to a kind of Motor Ventilation Cooling System, relate in particular to a kind of large-scale bulb through-flow pump assembly filtering type ventilating system, belong to the electromechanical equipment cooling field that ventilates.

Background technology

Large-scale bulb through-flow pump assembly open type ventilating system, comprise motor, bulb through-flow pump assembly bulb housing and blast pipe, the discharge pipe of ventilation blower and driving thereof, in bulb housing, be provided with bulb through-flow pump assembly motor, on bulb housing, the two ends of corresponding motor internal are provided with air inlet and air outlet.Ventilation blower is arranged on tubular through flow pump unit outside, is connected with the inlet end of bulb housing motor by blast pipe, is connected with discharge pipe to station in the outlet side of bulb housing motor.

When the work of open type ventilating system, ventilation blower air inlet air amount supercharging, passes through successively blast pipe, bulb housing motor air intake in station, enters motor stator and rotor and absorbs heat, arrive bulb housing motor outlet air end, then from discharge pipe is discharged to station.Open type ventilation cooling system, directly gets the cold air of ambient air as low-temperature receiver, and cold air enters motor and absorbs after heat, enters again atmosphere.Compared with traditional closed ventilation cooling system, the advantage such as open type ventilation cooling system has without aerial cooler and cooling water system thereof, and cost of equipment is low, and system is simple and reliable, and operating cost is low.But there is following subject matter in open type ventilation cooling system:

It is cooling that outside air directly enters motor ventilation, airborne dust can be adsorbed on motor radiating surface, particularly airborne dust granule mixes with the oil vapour that bearing lubrication forms, and is attached to motor coil, iron core, ventilation slot and air gap surface, forms grease, motor radiating surface resistance of heat transfer increases, reduce the radiating effect of motor, destroy electrical machine insulation, therefore, laying dust, grease must be removed in time, can only in the time of motor overhaul, carry out and remove motor grease.Result causes the major overhaul cycle short, and overhaul cost is high, and electrical machinery life is short.Therefore, need a kind of new ventilating system.

Summary of the invention

The object of this invention is to provide a kind of large-scale bulb through-flow pump assembly filtering type ventilating system and economy thereof and determine method, this ventilating system can be tackled the dust granule in outside air, assurance enters the cleanliness factor that in bulb, motor is carried out cooling air, greatly reduce gathering of electric machine iron core, winding, ventilation slot and air gap surface dirt and grease, guarantee ventilation cooling effect, reduce the impact on electrical machine insulation, extend overhaul life and the useful life of unit, save overhaul cost.

The object of the invention is to be achieved through the following technical solutions, large-scale bulb through-flow pump assembly filtering type ventilating system, comprise bulb through-flow pump assembly motor in ventilation blower and necessary electromotor thereof, bulb through-flow pump assembly and blast pipe, discharge pipe, bulb housing, on bulb housing, the two ends of corresponding its bulb inside tubular through flow pump unit motor are provided with air inlet and air outlet.Ventilation blower is arranged on bulb through-flow pump assembly outside, ventilation blower outlet is connected with the bulb housing air inlet of bulb through-flow pump assembly motor inlet end by blast pipe, is connected with discharge pipe to station at the bulb housing air outlet of bulb through-flow pump assembly motor outlet side.At described ventilation blower air inlet, filtrate is set, the air inlet of open type machine ventilation cooling system is filtered, stop it to enter in the motor in bulb housing.Before and after filtrate, section is provided with differential pressure measurement device, and pressure difference is shown to record, when pressure difference exceedes set point, is pointed out, and exceedes the more alarm of set point.According to the pressure reduction before and after ventilation blower air inlet filtrate, judge filter clogging situation, remove in time the dust of filter clogging or change filtrate.

Large-scale bulb through-flow pump assembly ventilation system of motor expense mainly comprises ventilating system cost of equipment, ventilating system operation power cost and consumptive material expense.The dust and the grease that affect host groups motor due to draft type gather situation, thereby affect major overhaul cycle, overhaul cost and useful life.

In order to analyze the quality of more different ventilation cooling systems, choose reasonable ventilating system, large-scale bulb through-flow pump assembly ventilating system economy of the present invention is determined method, in the research regular period, guaranteeing under the prerequisite that electric machine temperature rise evenly, does not exceed standard, the installation cost of unit ventilating system, operation expenditure on power and consumptive material takes and unit maintenance overhaul expense, preferentially select the ventilating system that total cost is few, cooling performance is good.Comprise following aspect:

A. motor ventilation heat radiation is calculated

Stator shaft orientation ventilation slot area

S ₁=2z ₁l ₁(h _n+b _n) （1）

In formula: h _nfor groove high (mm); b _nfor groove width (mm); l ₁for stator core length (mm); z ₁for number of stator slots.

Stator winding end film-cooled heat

S ₂=4πD ₁l _H （2）

In formula: D ₁for the diameter (mm) at stator winding place; l _hfor axis of winding extension elongation (mm).

The average temperature rising of stator core to inner air

$\mathrm{\Δ}{t}_{\mathrm{Fe}}=\frac{k_1{P}_{\mathrm{Fe}}+P_{\mathrm{Cu}}}{{\mathrm{\α}}_1{S}_n}---\left(3\right)$

In formula: P _fefor stator core caloric value (W); P _cufor stator winding caloric value (W); k ₁for coefficient, conventionally get 0.72～0.84, its physical significance is: in stator core caloric value, what in motor, air was taken away is only part caloric value, and remaining caloric value is directly taken away by the current in outside runner through stator casing; α ₁for stator core surface coefficient of heat transfer (W/(m ²℃)); S _nfor stator face of cylinder film-cooled heat (m ²).

The average temperature rising of stator winding to motor internal air

$\mathrm{\Δ}{t}_{\mathrm{Cul}}=\frac{c_1{P}_{\mathrm{Cu}}{R}_{\mathrm{CF}}{l}_t+(1-c_1)P_{\mathrm{Cu}}{R}_E{l}_E}{l_t+l_E}---\left(4\right)$

In formula: R _cFfor the thermal resistance (m between winding copper cash and iron core ²k/W); R _efor stator coil end thermal resistance (m ²k/W); c ₁for stator copper heating in winding amount is passed through the stator face of cylinder by the cooling shared ratio of air; l _tfor the live part length (mm) of stator winding; l _efor (2l _h) tip lengths (mm).

The average temperature rising of motor internal air to extraneous air

${\mathrm{\θ}}_B=\frac{P_{\mathrm{Fe}}+P_{\mathrm{Cu}}+P_f}{S_M{\mathrm{\α}}_B}---\left(5\right)$

In formula: P _ffor ventilation blower caloric value (W); S _mfor motor ventilation area of dissipation (m ²); α _bfor the surface coefficient of heat transfer (W/(m of motor internal and air ²k)).

The approximate air quantity of radial ventilation system

$Q_B=3.5{\left(\frac{n}{1000}\right)}^{3/4}{\left(\frac{{\mathrm{<figure-callout\; id="2"\; label="D\; H"\; filenames="140217174246.png"\; state="\{\{state\}\}">D</figure-callout>}}_H}{100}\right)}^2(z_k{l}_k+100)\&times;{10}^{-2}---\left(6\right)$

In formula: the rotating speed (r/min) that n is motor; D _h2for motor housing diameter (mm); z _kfor radial passage number; l _kfor the width (mm) of radial passage.

Radial ventilation system air pressure head

$\mathrm{\&Delta;}{p}_1=785{(n/1000)}^2{\mathrm{<figure-callout\; id="2"\; label="D\; H"\; filenames="140217174246.png"\; state="\{\{state\}\}">D</figure-callout>}}_H^2---\left(7\right)$

Equivalent windage Δ p with from centrifugal fan shaft to ventilating system ₂can draw by Fig. 1 P is that the motor feels hot power.

B. the Cooling calculation of the outer current of bulb to hot-air in bulb

If motor ambient air temperature is t ₀, the temperature t of runner water _w=t ₀-(3～5) ℃, with the hot air temperature of runner hydrothermal exchange be t _q.The surface film thermal conductance of runner water and bulb housing outer wall

$h_w=0.023{\mathrm{Re}}_w^{0.8}{\mathrm{Rr}}_w^{0.4}\frac{{\mathrm{\&lambda;}}_w}{D_w}{\mathrm{\&epsiv;}}_{\mathrm{ew}}---\left(8\right)$

In formula: Pr _w, λ _wbeing respectively temperature is t _wprandtl criterion number and the conductive coefficient of Shi Shui; Re _wfor the Reynolds number of current; D _wfor equivalent diameter; ε _ewfor correction factor.

The surface film thermal conductance of air and bulb housing inwall

$h_a=0.023R{e}_a^{0.8}P{r}_a^{0.4}\frac{{\mathrm{\&lambda;}}_a}{D_a}{\mathrm{\&epsiv;}}_{\mathrm{ea}}---\left(9\right)$

In formula: Pr _a, λ _abeing respectively temperature is t _qtime Prandtl criterion number and the conductive coefficient of hot-air; Re _afor the Reynolds number of air; D _afor equivalent diameter; ε _eafor correction factor.

The surface film thermal conductance of air and ventilation hole

$\left\{\begin{array}{cc}{h}_v=h(1+1.2\sqrt{v})& v>65m/s\\ h_v=h(1+k_{0}v)& v\&le;65m/s\end{array}\right.---\left(10\right)$

In formula: v is air velocity; H is smooth air surface film thermal conductance, relevant with heating surface, span 1.33～1.67; k ₀for air-flow brushes efficiency factor, conventionally select 0.1.

The thermal conduction resistance of the cylindrical shape Gu Bi such as stator, rotor, support is obtained by following formula

$R=\frac{1}{2\mathrm{\&pi;L\&lambda;}}\&CenterDot;\ln \frac{D_2}{D_1}---\left(11\right)$

In formula: the conductive coefficient that λ is Gu Bi; L is the length of Gu Bi, D ₁, D ₂for the internal-and external diameter of Gu Bi.

Insulating barrier, anticorrosive coat and coil and between the thermal conduction resistance of air gap etc. (planomural) obtain by following formula

$R=\frac{\mathrm{\&delta;}}{\mathrm{s\&lambda;}}---\left(12\right)$

In formula: the conductive coefficient that λ is planomural; S is the heat exchange area of planomural, the thickness that δ is planomural.

The actual amount of cooling water of outer wall runner water

$P=\frac{(t_Q-t_w)}{\mathrm{\&Sigma;R}}\&CenterDot;\frac{1-e^{-K}}{K}---\left(13\right)$

In formula: Σ R is the entire thermal resistance of heat exchange between water and bulb and air; K=10 ^-3/ (Σ RQC _a).

Cold junction air themperature

t _c=(t _Q-t _w)e ^-K+t _w （14）

Ventilation quantity

Q _B=P/[C _a(t _Q-t _c)] （15）

In formula: C _afor the volumetric specific heat capacity (J/(m of air ³k)).

Windage in bulb housing

$\mathrm{\&Delta;}{p}_3=\mathrm{\&Sigma;}[{\mathrm{\&lambda;}}_i\frac{1}{R_{\mathrm{si}}}\&CenterDot;\frac{v_i^2\mathrm{\&rho;}}{2}\&CenterDot;l_i+{\mathrm{\&xi;}}_i\frac{v_i^2\mathrm{\&rho;}}{2}]---\left(16\right)$

In formula: λ is on-way resistance coefficient; L is along Cheng Changdu (m); ξ is coefficient of partial resistance; ρ is fluid density (kg/m ³); R _sfor hydraulic radius (m).Subscript " i " represents i item on-way resistance or local resistance.

C. filtrate dedusting resistance calculates

The resistance of filtrate dedusting is

$\mathrm{\&Delta;}{p}_4={\mathrm{\&xi;}}_0{\mathrm{\&mu;}}_a{v}_F+{\mathrm{\&alpha;}}_m{\mathrm{\&mu;}}_a\mathrm{y\&tau;}{v}_F^2---\left(17\right)$

In formula: μ _a, v _fbe respectively air force viscosity and flow velocity; ζ ₀for filtering material resistance coefficient; a _mfor the average resistivity of dust layer; τ is filtrate stream time; Y is filtrate import department dust content.

D. ventilation circuit resistance calculates

The effective pressure reduction of ventilation blower

$\mathrm{\&Delta;p}=K_3\underset{i=1}{\overset{4}{\mathrm{\&Sigma;}}}\mathrm{\&Delta;}{p}_i---\left(18\right)$

In formula: K ₃for ventilation coefficient, K ₃get 1.05～1.15.

Can be obtained by formula (18), when motor operation, ventilation blower effective power is P _t=Δ pQ _b

E. selection of filtering material

According to room air standard, being suspended in the dust that equivalent diameter in air is less than 10 μ m is 0.15mg/m ³, can select medium effeciency filter, ash removal efficiency is 70%, dust containing capacity is 600g/m ².The total initial resistance of filter is 50Pa, and whole resistance is 100Pa, and required ventilation blower pressure reduction increases.Pressure reduction before and after monitoring filtrate, the replacing cleaning filtrate cycle is about continuous operation 1152h, also can adopt beating, vibration to remove dust, extends filtrate life cycle.

F. economic analysis

System total cost is cost of equipment, operation power cost and consumptive material expense and three sums of overhaul cost, and the minimum system of total cost is for selecting system.

The present invention has following beneficial effect:

Large-scale bulb through-flow pump assembly filtering type ventilating system, arranges filter dirt material at ventilation blower air inlet, and the air that ventilating system is directly taken from station filters.In the present invention, air, via filtrate, centrifugal blower, blast pipe, tubular through flow pump unit motor, discharge pipe, is then discharged station.Air inlet in ventilating system adds filtrate, and the dust granule in interception outside air guarantees to enter the cleanliness factor that in bulb, motor is carried out cooling air, has greatly reduced gathering of electric machine iron core, winding, ventilation slot and air gap surface dust and grease.Therefore, the present invention has following beneficial effect:

First, reduce along with the surface heat exchanging performance on the passing motor radiating surface of running time and the decline of heat-conductive characteristic, substantially do not need to increase ventilation quantity to moving the later stage, still can guarantee the cooling effect that ventilates, thereby save the operating cost that traditional open type ventilating system increases because of operation later stage increase ventilation quantity.

The second, the degree of gathering of motor radiating surface dirt and grease is the major control sexual factor in large pump major overhaul cycle.The significantly minimizing that motor radiating surface dirt and grease gather, has greatly extended the major overhaul cycle, has saved overhaul cost.

The 3rd, the minimizing that motor radiating surface dirt and grease gather, has reduced the impact on electrical machine insulation, has extended the useful life of unit.

The 4th, pressure reduction before and after observation ventilation blower air inlet filtrate, judges stopping state, removes in time filter clogging dust or changes filtrate, can realize the optimization of filter material replacement frequency, reduces ventilation circuit resistance, reduces filtrate consumptive material.

Accompanying drawing explanation

Fig. 1 is embodiment of the present invention tubular through flow pump unit axial ventilation system equivalence windage;

Fig. 2 is the general arrangement of large-scale bulb through-flow pump assembly filtering type ventilating system of the present invention;

Fig. 3 is the structural representation of filtrate in Fig. 2;

In figure: 1 filtrate, 1-1 filtrate, 1-2 dust, 2 bolts, 3 differential pressure measurement devices, 4 ventilation blowers, 5 ventilation blower necessary electromotors, 6 ventilation blower outlets, 7 blast pipes, 8 tubular through flow pump unit motor stators, 9 tubular through flow pump unit rotors, 10 stators, 11 air inlets, 12 air outlets, 13 discharge pipes, 14 buttresses, 15 bulb housings, 16 impellers.

Embodiment

Below in conjunction with accompanying drawing, the invention will be further described.

As Fig. 2,3, bulb through-flow pump assembly shell is supported on buttress 14.Bulb through-flow pump assembly critical piece comprises impeller 16, pump shaft, stator 10, bulb housing 15, tubular through flow pump unit motor stator 8, tubular through flow pump unit rotor 9.

Large-scale bulb through-flow pump assembly filtering type ventilating system, comprises ventilation blower necessary electromotor 5, ventilation blower 4 and bulb through-flow pump assembly and into and out of airduct.Ventilation blower necessary electromotor 5 drives and connects ventilation blower 4.Filtrate 1 is installed in ventilation blower 4 imports, and filtrate 1 use bolt 2 is fixed on ventilation blower import.Differential pressure measurement device 3 is installed in filtrate 1 front and back.Ventilation blower exports 6 connecting lamp cell-shell blast pipes 7.On bulb housing 15, be respectively equipped with air inlet 11 and air outlet 12 at the two ends of motor.Blast pipe 7 is connected with bulb housing air inlet 11.After bulb housing air outlet 12, pick out airduct 13 to station.

After pump assembly operation, ventilation blower 4 under the driving of ventilation blower necessary electromotor 5 by air intake ventilation blower 4.In air with dust 1-2 just blocked thereon attached by filtrate 1-1.Through filtered air, under the effect of ventilation blower 4, stator 8, the rotor 9 that enters the interior tubular through flow pump unit of bulb housing 15 motor through ventilation blower outlet 6, blast pipe 7, air inlet 11 ventilates cooling, finally discharges station from air outlet 12, discharge pipe 13.Pressure tester 3 is set, observation pressure reduction before and after filtrate.More the filter wash material cycle is about continuous operation 1152h, also can adopt the methods such as beating, vibration to remove the dust on filtrate, extends filtrate life cycle.

Certain large-scale bulb through-flow pump assembly, if employing system 1---traditional open type ventilating system, motor adopts stator adherence formula shell current cooling segment heat, and most of heat is cooling by open type forced ventilation cooling system.If the bulb housing life-span calculated by 16 years, centrifugal blower efficiency is by 80% calculating, and matched with blower electric efficiency is calculated by 86%, and year running time, electricity price was by 0.7 yuan/(kWh) calculating by 5000h.Overhaul cost of single pump unit is about 160,000 yuan, and the 1 host groups overhaul life of ventilating system is 4 years.Consider in unit running process, due to the increase of motor radiating surface dirt and grease thickness, need to increase ventilation quantity guarantee ventilation effect.If along with the increase of running time, to operation the end of term (after 4 years), ventilation quantity is linear increases 50%.If adopt system 2 of the present invention---filtering type ventilating system, only increased little filtrate consumptive material expense, but the host groups overhaul life can extend to 8 years, and saved ventilation operating cost.System 1 compares as table 1 with the comprehensive economy of system 2.

The comparison of two kinds of cooling system economy of table 1 bulb through-flow pump assembly motor

Can find out, system of the present invention (system 2) is compared with cooling system described in background technology (system 1), and annual operating cost reduces 0.275 ten thousand yuan, and single unit reduces 2.2 ten thousand yuan in 8 years.System 2 single unit is saved 160,000 yuan of overhaul costs in 8 years, and therefore, single unit 8 annual total costs are saved approximately 18.14 ten thousand yuan.Therefore, adopt filtering type ventilating system of the present invention, extended the major overhaul cycle, reduced overhaul cost and ventilating system operating cost, filtrate is cheap, replacing is convenient, and, motor, for a long time in the good ventilation state of cooling, is conducive to extend the useful life of unit.

Claims (8)

1. large-scale bulb through-flow pump assembly filtering type ventilating system, comprise ventilation blower and necessary electromotor thereof, bulb through-flow pump assembly and blast pipe, discharge pipe, bulb through-flow pump assembly motor in bulb housing, the bulb housing at corresponding bulb through-flow pump assembly motor two ends is provided with air inlet and air outlet, ventilation blower is arranged on bulb through-flow pump assembly outside, ventilation blower outlet is connected with bulb housing air inlet by blast pipe, bulb housing air outlet connects discharge pipe, it is characterized in that, described ventilation blower import is provided with the filtrate that air inlet is filtered, before and after filtrate, be provided with differential pressure measurement device, according to the pressure reduction of measuring, judge filter clogging situation, remove in time the dust of filter clogging or change filtrate.

2. large-scale bulb through-flow pump assembly filtering type ventilating system economy as claimed in claim 1 is determined method, it is characterized in that, described definite method comprises the following steps:

A. motor ventilation heat radiation is calculated;

B. the Cooling calculation of the outer current of bulb to hot-air in bulb;

C. filtrate dedusting resistance calculates;

D. ventilation circuit resistance calculates;

E. selection of filtering material;

F. economic analysis.

3. large-scale bulb through-flow pump assembly filtering type ventilating system economy according to claim 2 is determined method, it is characterized in that, motor ventilation heat radiation is calculated as described in steps A:

Stator shaft orientation ventilation slot area

S ₁=2z ₁l ₁(h _n+b _n)

In formula: h _nfor groove high; b _nfor groove width; l ₁for stator core length; z ₁for number of stator slots;

Stator winding end film-cooled heat

S ₂=4πD ₁l _H

In formula: D ₁for the diameter at stator winding place; l _hfor axis of winding extension elongation;

The average temperature rising of stator core to inner air

$\mathrm{\&Delta;}{t}_{\mathrm{Fe}}=\frac{k_1{P}_{\mathrm{Fe}}+P_{\mathrm{Cu}}}{{\mathrm{\&alpha;}}_1{S}_n}$

In formula: k ₁for coefficient, conventionally get 0.72～0.84, its physical significance is: in stator heat is calculated, what in motor, air was taken away is only effectively loss of part, and remaining part loss is directly taken away by current in outside runner through stator casing; P _cu, P _febe respectively stator copper loss, iron loss; α ₁for stator core surface coefficient of heat transfer; S _nfor stator face of cylinder film-cooled heat;

The average temperature rising of stator winding to motor internal air

$\mathrm{\&Delta;}{t}_{\mathrm{Cul}}=\frac{c_1{P}_{\mathrm{Cu}}{R}_{\mathrm{CF}}{l}_t+(1-c_1)P_{\mathrm{Cu}}{R}_E{l}_E}{l_t+l_E}$

In formula: R _cFfor the thermal resistance between winding copper cash and iron core; R _efor stator coil end thermal resistance; c ₁for stator copper loss passes through the stator face of cylinder by the shared ratio of air amount of cooling water; l _tfor the live part length of stator winding; l _efor tip lengths;

The average temperature rising of motor internal air to extraneous air

${\mathrm{\&theta;}}_B=\frac{P_{\mathrm{Fe}}+P_{\mathrm{Cu}}+P_f}{S_M{\mathrm{\&alpha;}}_B}$

In formula: P _ffor ventilation blower caloric value; S _mfor motor ventilation area; α _bfor motor internal and air surface thermal transmission coefficient;

The approximate air quantity of radial ventilation system

$Q_B=3.5{\left(\frac{n}{1000}\right)}^{3/4}{\left(\frac{D_{H2}}{100}\right)}^2(z_k{l}_k+100)\&times;{10}^{-2}$

In formula: the rotating speed that n is motor; z _kfor radial passage number; l _kfor the width of radial passage; D _h2for motor housing diameter;

Radial ventilation system air pressure head

$\mathrm{\&Delta;}{p}_1=785{(n/1000)}^2{D}_{H2}^2$

In formula: the rotating speed that n is motor;

Equivalent windage Δ p with from centrifugal fan shaft to ventilating system ₂can draw by the relation curve of axial equivalent windage and unit motor speed heating power.

4. large-scale bulb through-flow pump assembly filtering type ventilating system economy according to claim 2 is determined method, it is characterized in that, the outer current of bulb to the Cooling calculation of hot-air in bulb are described in step B:

If motor ambient air temperature is t ₀, the temperature t of runner water _w=t ₀-(3～5) ℃, with the hot air temperature of runner hydrothermal exchange be t _q, the surface film thermal conductance of runner water and bulb housing outer wall

$h_w=0.023{\mathrm{Re}}_w^{0.8}{\mathrm{Rr}}_w^{0.4}\frac{{\mathrm{\&lambda;}}_w}{D_w}{\mathrm{\&epsiv;}}_{\mathrm{ew}}$

In formula: Pr _w, λ _wbeing respectively temperature is t _wprandtl criterion number and the conductive coefficient of Shi Shui; Re _wfor the Reynolds number of current; D _wfor equivalent diameter; ε _ewfor correction factor;

The surface film thermal conductance of air and bulb housing inwall

$h_a=0.023R{e}_a^{0.8}P{r}_a^{0.4}\frac{{\mathrm{\&lambda;}}_a}{D_a}{\mathrm{\&epsiv;}}_{\mathrm{ea}}$

In formula: Pr _a, λ _abeing respectively temperature is t _qtime Prandtl criterion number and the conductive coefficient of hot-air; Re _afor the Reynolds number of air; D _afor equivalent diameter; ε _eafor correction factor;

The surface film thermal conductance of air and ventilation hole

$\left\{\begin{array}{cc}{h}_v=h(1+1.2\sqrt{v})& v>65m/s\\ h_v=h(1+k_{0}v)& v\&le;65m/s\end{array}\right.$

In formula: v is air velocity; H is smooth air surface film thermal conductance, relevant with heating surface, span 1.33～1.67; k ₀for air-flow brushes efficiency factor, conventionally select 0.1;

The thermal conduction resistance of the cylindrical shape Gu Bi such as stator, rotor, support is obtained by following formula

$R=\frac{1}{2\mathrm{\&pi;L\&lambda;}}\&CenterDot;\ln \frac{D_2}{D_1}$

In formula: the conductive coefficient that λ is Gu Bi; L is the length of Gu Bi, D ₁, D ₂for the internal-and external diameter of Gu Bi;

Insulating barrier, anticorrosive coat and coil and between the thermal conduction resistance of air gap etc. (planomural) obtain by following formula

$R=\frac{\mathrm{\&delta;}}{\mathrm{s\&lambda;}}$

In formula: the conductive coefficient that λ is planomural; S is the heat exchange area of planomural, the thickness that δ is planomural;

The actual amount of cooling water of outer wall runner water

$P=\frac{(t_Q-t_w)}{\mathrm{\&Sigma;R}}\&CenterDot;\frac{1-e^{-K}}{K}$

In formula: Σ R is the entire thermal resistance of heat exchange between water and bulb and air; K=10 ^-3/ (Σ RQC _a); E is natural constant;

Cold junction air themperature

t _c=(t _Q-t _w)e ^-K+t _w

Ventilation quantity

Q _B=P/[C _a(t _Q-t _c)]

In formula: C _afor the volumetric specific heat capacity J/(m of air ³k);

Windage in bulb housing

$\mathrm{\&Delta;}{p}_3=\mathrm{\&Sigma;}[{\mathrm{\&lambda;}}_i\frac{1}{R_{\mathrm{si}}}\&CenterDot;\frac{v_i^2\mathrm{\&rho;}}{2}\&CenterDot;l_i+{\mathrm{\&xi;}}_i\frac{v_i^2\mathrm{\&rho;}}{2}]$

In formula: λ is on-way resistance coefficient; L is along Cheng Changdu; ξ is coefficient of partial resistance; ρ is fluid density; R _sfor hydraulic radius; Subscript " i " represents i item on-way resistance or local resistance.

5. large-scale bulb through-flow pump assembly filtering type ventilating system economy according to claim 2 is determined method, it is characterized in that, filtrate dedusting resistance is calculated as described in step C:

$\mathrm{\&Delta;}{p}_4={\mathrm{\&xi;}}_0{\mathrm{\&mu;}}_a{v}_F+{\mathrm{\&alpha;}}_m{\mathrm{\&mu;}}_a\mathrm{y\&tau;}{v}_F^2$

In formula: μ _a, v _fbe respectively air viscosity and flow velocity; ζ ₀, a _mfor resistance coefficient and the average resistivity of dust layer of filtrate; τ is filtrate stream time; Y is filtrate import department dust content.

6. large-scale bulb through-flow pump assembly filtering type ventilating system economy according to claim 2 is determined method, it is characterized in that, ventilation circuit resistance is calculated as described in step D:

The effective pressure reduction of ventilation blower

$\mathrm{\&Delta;p}=K_3\underset{i=1}{\overset{4}{\mathrm{\&Sigma;}}}\mathrm{\&Delta;}{p}_i$

In formula: K ₃for ventilation coefficient, K ₃get 1.05～1.15;

When motor operation, ventilation blower effective power is P _t=Δ pQ _b.

7. large-scale bulb through-flow pump assembly filtering type ventilating system economy according to claim 2 is determined method, it is characterized in that, selection of filtering material is described in step e:

According to room air standard, being suspended in the dust that equivalent diameter in air is less than 10 μ m is 0.15mg/m ³, select medium effeciency filter, ash removal efficiency is 70%, dust containing capacity is 600g/m ²; The total initial resistance of filter is 50Pa, and required ventilation blower pressure reduction increases, and whole resistance is 100Pa, pressure reduction before and after monitoring filtrate, and the replacing cleaning frequency can be defined as moving 1152h.

8. large-scale bulb through-flow pump assembly filtering type ventilating system economy according to claim 2 is determined method, it is characterized in that, described in step F, economic analysis is: system total cost is cost of equipment, operation power cost and three sums of overhaul cost, and the less system of total cost is possible systems.

Images