CN103995017B

CN103995017B - A kind of experimental technique measuring cyclical heat transmission coefficient

Info

Publication number: CN103995017B
Application number: CN201410139701.3A
Authority: CN
Inventors: 赵增武; 张亚竹; 胡强
Original assignee: Inner Mongolia University of Science and Technology
Current assignee: Inner Mongolia University of Science and Technology
Priority date: 2014-04-04
Filing date: 2014-04-04
Publication date: 2016-08-17
Anticipated expiration: 2034-04-04
Also published as: CN103995017A

Abstract

The invention discloses a kind of experimental technique measuring cyclical heat transmission coefficient, for measuring the coefficient of heat transfer in various heat exchange cycle.The device that this experimental technique is used includes: scalable rotating speed rotate cylinder, scalable spray angle and the nozzle of jetting height, be placed in the heater of drums inside, the thermocouple being embedded in roller tube, temperature collection device are electrically connected to thermocouple, and are exported by the temperature signal of thermocouple.The method of experiment includes the foundation of mathematical model, discrete model, and according to indirect problem algorithm Numerical heat transfer coefficient, and according to steps such as default convergency value checking data.It is fast that this experimental technique has calculating speed, the advantage that result degree of accuracy is high, and can select the material of test as required, and can simulate the multiple state of cooling, the surface coefficient of heat transfer under the different cooler environment of test, applied widely.

Description

A kind of experimental technique measuring cyclical heat transmission coefficient

Technical field

The present invention relates to the coefficient of heat transfer and measure this technical field, a kind of experiment measuring cyclical heat transmission coefficient Method.

Background technology

In industry cooling processing procedure, the size of the coefficient of heat transfer decides the size of intensity of cooling, it is possible to determine difference Cooling water inflow, different spray nozzles jetting height, relation between different spray angle and the coefficient of heat transfer, have regulation intensity of cooling Important meaning, to formulating rational cooling system, the quality improving product has conclusive effect.

Cyclical heat transmission is present in the production procedure of commercial production batch (-type) cooling, i.e. allows cooled workpiece once pass through The cooling nozzle arranged, workpiece is in cooled state through nozzle, is transmitted to next spray when leaving nozzle spray regime Non-cooled or backheat state it is in during mouth.Such as in the secondary cooling process of continuous casting, steel billet is through cooling twice region Time, the nozzle that steel billet is arranged once cools down, the non-cooled region between nozzle, and the wick-containing of steel billet can be to unofficial biography Heat, allows billet surface rise again.Cyclical heat transmission has cooling uniformly, the feature that workpiece thermal stress is little, the test various heat exchange cycle, The heat transfer characteristic of different intensities of cooling suffers from important finger to the arrangement of nozzle, workpiece transfer rate, air pressure hydraulic pressure setting etc. Lead meaning.

The mensuration of cyclical heat transmission coefficient uses heating steel sheet mostly at present, and the method moving horizontally nozzle cools down, There is significant limitation in this method.The geometrical property being primarily due to steel plate can not well process thermal stress, cooled Being easily deformed in journey, and the cooling testing time of steel plate is limited, change frequently, Meteorological is higher.Secondly the method cannot Carry out continuous print injection, can only reciprocating spray, do not meet the injection feature of cyclical heat transmission.Steel plate type moving nozzle again Method cannot freely regulated spray angle, it is impossible to measure the heat transfer characteristic of angle of inclination injection.

Therefore, considering testing expense, testing range of accommodation, on the basis of measuring accuracy, it is provided that one effectively measures week The experimental technique of the phase property coefficient of heat transfer formulates rational cooling system in producing industry cooling positive effect.

Summary of the invention

The technical issues that need to address of the present invention are that the defect overcoming prior art, it is provided that a kind of mensuration is periodically changed The experimental technique of hot coefficient, is used for testing unlike material raw material heat flow under different cycles heat exchange, the coefficient of heat transfer, reaches meter Calculation speed is fast, and computational accuracy is high.

For solving the problems referred to above, the present invention adopts the following technical scheme that

A kind of experimental technique measuring cyclical heat transmission coefficient, it includes an experimental provision, and this device includes that scalable turns The rotating cylinder, scalable spray angle and the nozzle of jetting height, be placed in the heater of drums inside, be embedded in cylinder of speed Thermocouple in cylinder, it is electrically connected to thermocouple and temperature collection device that temperature signal is exported；

Specific experiment method comprises the following steps:

The first step: utilize the material needing test to make rotation cylinder, be placed on experimental provision, need regulation according to test The rotating speed of good cylinder；According to the cooler environment of required simulation, regulate jetting height and the spray angle of nozzle；Utilize heating Cylinder is heated by device；

Second step, utilizes temperature collection device record inner barrel temperature data, it is thus achieved that cylinder quenching temperature lowering curveN is the temperature collection point number set, and utilizes thermometer to record temperature T of nozzle cooling water_cW；

3rd step, composes drum surface hot-fluid initial valueδ is constant, i=1 ..., n；Calculate internal temperature field

4th step, meter sensitivity coefficient X_ik, utilize second stepAnd temperature fieldSubstitute into formula and try to achieve sensitivity coefficient:

X_{i k} = \frac{\partial}{\partial q_{k}} (T_{i}^{c} (q_{k})) \approx \frac{T_{i}^{c} (q_{1}^{0} ..., q_{k}^{0} + {δq}_{k}^{0}, ... q_{n}^{0}) - T_{i}^{c} (q_{1}^{0} ..., q_{k}^{0}, ... q_{n}^{0})}{{δq}_{k}};

5th step, solvesFirst three step is utilized to obtainX_ikSubstitute into formula and try to achieve optimal value

q_{i}^{1} = q_{i}^{0} + {({X_{i k}}^{T} X_{i k})}^{- 1} {X_{i k}}^{T} (T_{i}^{m} - T_{i}^{c} (q_{i}^{0}));

6th step, it is judged thatWhether meet convergence to sentence

| \frac{q_{i}^{1} - q_{i}^{0}}{q_{i}^{1}} | < ϵ, i = 1, ..., n;

Such as satisfied convergence, then substitute into formula and obtain heat transfer coefficient h_i, terminate；

h_{i} = \frac{q_{i}^{1}}{T_{i}^{m} - T_{c W}}

As being unsatisfactory for convergence, then make

q_{i}^{0} = q_{i}^{1}, i = 1, ..., n;

It is back to second step, until meeting till convergence gauge calculates h.

Further, the material of described rotation cylinder can need corresponding selection according to test.

Further, in described 3rd step, each point for measuring temperature of cylinder is utilized to set up the method for mathematical Model of Heat Transfer as follows:

ρ c \frac{\partial T}{\partial t} = \frac{1}{r} \frac{\partial}{\partial r} (r λ \frac{\partial T}{\partial t}) + \frac{1}{r} \frac{\partial}{\partial θ} (\frac{λ}{r} \frac{\partial T}{\partial θ}) (r &Element; (s_{1}, s_{2}), θ &Element; [0, 2 π), t > 0)

Initial condition: T (r, 0)=T₀(r∈[s₁,s₂], t=0)

Boundary condition T |_R=s=T_f(r=s₁, t ＞ 0)

- λ \frac{\partial T}{\partial r} |_{r = s_{2}} = q (t) (r = s_{2}, t > 0)

In formula: λ is cylinder heat conductivity/w (m DEG C)^-1；ρ is cylinder density/Kg m^-3；C is the level pressure ratio of cylinder Thermal capacitance/J (kg DEG C)^-1；T be temperature/DEG C；T is the moment；R is radial coordinate, and θ is circumferencial direction coordinate.

According to heat balance principle, under unsteady state condition, enter the generation of the heat flow of cylinder any point p with heat-conducting mode Count and equal to its thermal change amount, the method setting up heat transfer discrete model be as follows:

\{\begin{matrix} \frac{λ (r_{P} - Δ r / 2)}{r_{P} {Δr}^{2}} T_{S}^{k + 1} + \frac{λ}{r_{P}^{2} {Δθ}^{2}} T_{W}^{k + 1} - (\frac{λ (r_{P} - Δ r / 2)}{r_{P} {Δr}^{2}} + \frac{2 λ}{r_{P}^{2} {Δθ}^{2}} + ρ c) T_{P}^{k + 1} = - {ρcT}_{P}^{k} - \frac{q (r_{P} + Δ r / 2)}{r_{P} Δ r} \\ (m = 1) \\ \frac{λ (r_{P} - Δ r / 2)}{r_{P} {Δr}^{2}} R_{S}^{k + 1} + \frac{λ}{r_{P}^{2} {Δθ}^{2}} T_{W}^{k + 1} - (\frac{λ (r_{P} - Δ r / 2)}{r_{P} {Δr}^{2}} + \frac{2 λ}{r_{P}^{2} {Δr}^{2}} + ρ c) T_{P}^{k + 1} + \frac{λ}{r_{P}^{2} {Δθ}^{2}} T_{E}^{k + 1} + \frac{λ (r_{P} + Δ r / 2)}{r_{P} {Δr}^{2}} T_{N}^{k + 1} = - {ρcT}_{P}^{k} \\ (m = 2, 3, ..., N - 1) \\ \frac{λ}{r_{P}^{2} {Δθ}^{2}} T_{W}^{k + 1} - (\frac{λ (r_{P} - Δ r / 2)}{r_{P} {Δr}^{2} / 2} + \frac{2 λ}{r_{P}^{2} {Δθ}^{2}} + \frac{λ (r_{P} + Δ r / 2)}{r_{P} {Δr}^{2}} + ρ c) T_{P}^{k + 1} + \frac{λ}{r_{P}^{2} {Δθ}^{2}} T_{E}^{k + 1} + \frac{λ (r_{P} + Δ r / 2)}{r_{P} {Δr}^{2}} T_{N}^{k + 1} = - {ρcT}_{P}^{k} - \frac{λ (r_{P} - Δ r / 2)}{r_{P} {Δr}^{2} / 2} T_{f} \\ (m = N) \end{matrix}

M is the number of plies of p place, arbitrfary point grid；Temperature for k moment p point；The temperature value minute of the four direction of p point Other T_W,T_E,T_S,T_N；r_PRadius for p point；Relevant parameter is substituted into above-mentioned solving equationsThus It is apparent from the temperature at the grid of thermocouple place

Further, described ε < 0.001 is set.

Further, described temperature collection point number n=24, its distribution foundation is time step Δ τ=1s, spatial mesh size Δ θ=π/12, Δ r=1mm.

Beneficial effects of the present invention:

(1) owing to using the form rotating cylinder in apparatus of the present invention, the deformation problems of thermal stress is overcome well, existing The deformation having technology light plate to cool down is relatively big, and after experiment, deformation is serious for several times, it is impossible to experiment is repeated several times, and cylinder solves well Determined this problem, it is possible to experiment be repeated several times, and use the form of cylinder make drums inside closer to adiabatci condition, with reality In the cooling twice of border, the middle adiabatci condition of steel billet is consistent.

(2) cylinder of the present invention can be made up of the material of required measurement, it is adaptable to the heat transfer of multiple unlike material blank is The mensuration of number.

(3) drum rotation speed of the present invention is adjustable, and jetting height and the spray angle of nozzle are the most adjustable, therefore can simulate multiple Methods for cooling, it is achieved periodically cooling test, such that it is able to test out the cooling characteristics of different cooling cycle.

(4) include the proof procedure of indirect problem algorithm during experimental technique of the present invention, just demonstrate indirect problem algorithm Really property and feasibility so that experiment the data obtained is relatively reliable.

(5) experimental technique of the present invention take into account input hot-fluid Annual distribution, all channel errors of all moment to experiment The impact of precision, controls experimental error average rank 10^-14The order of magnitude, precision is high.

Accompanying drawing explanation

Fig. 1 be mathematical model of the present invention set up schematic diagram；

Fig. 2 is mathematical model stress and strain model schematic diagram of the present invention；

Fig. 3 is method for inverse calculation flow chart of the present invention；

Fig. 4 is that method for inverse calculation of the present invention verifies flow chart；

Fig. 5 is that the present invention inputs hot-fluid time distribution map；

Fig. 6 is error validity lab diagram of the present invention；

Fig. 7 is the schematic diagram of experimental provision of the present invention；

Detailed description of the invention

The invention provides a kind of experimental technique measuring cyclical heat transmission coefficient, its experimental provision used such as Fig. 7 Shown in (being diagrammatically only by delivery nozzle and cylinder), rotate cylinder, scalable spray angle and jetting height including scalable rotating speed Nozzle, it is placed in the heater of drums inside, the thermocouple being embedded in roller tube, is electrically connected to thermocouple and by temperature signal The temperature collection device of output.

Concrete method of testing is as follows:

First, utilize the material needing test to make rotation cylinder, be placed on experimental provision, regulate according to test needs The rotating speed of cylinder；

Secondly, according to the cooler environment of required simulation, jetting height and the spray angle of nozzle are regulated；

Finally, utilize heater that cylinder is heated, record the temperature value of 24 points for measuring temperature on cylinder.

Concrete calculation procedure is as follows:

The first step, utilizes temperature collection device record inner barrel temperature data, it is thus achieved that cylinder quenching temperature lowering curveUtilize thermometer to measure in nozzle to cool down temperature T of water_cW；

Second step, composes drum surface hot-fluid initial valueCalculate internal temperature ?

Mathematical Model of Heat Transfer is set up according to 24 point for measuring temperature data, as it is shown in figure 1,

1、

ρ c \frac{\partial T}{\partial t} = \frac{1}{r} \frac{\partial}{\partial r} (r λ \frac{\partial T}{\partial t}) + \frac{1}{r} \frac{\partial}{\partial θ} (\frac{λ}{r} \frac{\partial T}{\partial θ}) (r &Element; (s_{1}, s_{2}), θ &Element; [0, 2 π), t > 0)

2, initial condition: T (r, 0)=T₀(r∈[s₁,s₂], t=0)

3, boundary condition T |_R=s=T_f(r=s₁, t ＞ 0)

- λ \frac{\partial T}{\partial r} |_{r = s_{2}} = q (t) (r = s_{2}, t > 0)

θ direction has 24 position measurement points, takes time step Δ τ=1s, spatial mesh size Δ θ=π/12, Δ r= 1mm, initial temperature T₀=1200 DEG C, physical parameter, the present embodiment chooses 304 rustless steels, as follows: ρ=7800kg m^-1；λ= 0.0147T+15w·(m·k)^-1；C=0.15T+505J (kg k)^-1；

According to heat balance principle, under unsteady state condition, enter the generation of the heat flow of cylinder any point p with heat-conducting mode Count and equal to its thermal change amount, set up heat transfer discrete model, as shown in Figure 2:

\{\begin{matrix} \frac{λ (r_{P} - Δ r / 2)}{r_{P} {Δr}^{2}} T_{S}^{k + 1} + \frac{λ}{r_{P}^{2} {Δθ}^{2}} T_{W}^{k + 1} - (\frac{λ (r_{P} - Δ r / 2)}{r_{P} {Δr}^{2}} + \frac{2 λ}{r_{P}^{2} {Δθ}^{2}} + ρ c) T_{P}^{k + 1} = - {ρcT}_{P}^{k} - \frac{q (r_{P} + Δ r / 2)}{r_{P} Δ r} \\ (m = 1) \\ \frac{λ (r_{P} - Δ r / 2)}{r_{P} {Δr}^{2}} R_{S}^{k + 1} + \frac{λ}{r_{P}^{2} {Δθ}^{2}} T_{W}^{k + 1} - (\frac{λ (r_{P} - Δ r / 2)}{r_{P} {Δr}^{2}} + \frac{2 λ}{r_{P}^{2} {Δr}^{2}} + ρ c) T_{P}^{k + 1} + \frac{λ}{r_{P}^{2} {Δθ}^{2}} T_{E}^{k + 1} + \frac{λ (r_{P} + Δ r / 2)}{r_{P} {Δr}^{2}} T_{N}^{k + 1} = - {ρcT}_{P}^{k} \\ (m = 2, 3, ..., N - 1) \\ \frac{λ}{r_{P}^{2} {Δθ}^{2}} T_{W}^{k + 1} - (\frac{λ (r_{P} - Δ r / 2)}{r_{P} {Δr}^{2} / 2} + \frac{2 λ}{r_{P}^{2} {Δθ}^{2}} + \frac{λ (r_{P} + Δ r / 2)}{r_{P} {Δr}^{2}} + ρ c) T_{P}^{k + 1} + \frac{λ}{r_{P}^{2} {Δθ}^{2}} T_{E}^{k + 1} + \frac{λ (r_{P} + Δ r / 2)}{r_{P} {Δr}^{2}} T_{N}^{k + 1} = - {ρcT}_{P}^{k} - \frac{λ (r_{P} - Δ r / 2)}{r_{P} {Δr}^{2} / 2} T_{f} \\ (m = N) \end{matrix}

Internal node P at r direction adjacent node N, S, is W, E with it at θ direction adjacent node with it, and each temperature can use phase The node temperature T answered_N, T_S, T_W, T_ERepresent.

Relevant parameter is substituted into above-mentioned solving equationsThus it is apparent from thermocouple place grid The temperature at place

3rd step, meter sensitivity coefficient X, utilize second stepAnd temperature fieldSubstitute into formula and try to achieve sensitivity coefficient:

X_{i k} = \frac{\partial}{\partial q_{k}} (T_{i}^{c} (q_{k})) \approx \frac{T_{i}^{c} (q_{1}^{0} ..., q_{k}^{0} + {δq}_{k}^{0}, ... q_{n}^{0}) - T_{i}^{c} (q_{1}^{0} ..., q_{k}^{0}, ... q_{n}^{0})}{{δq}_{k}};

4th step, solvesFirst three step is utilized to obtainX substitutes into formula and tries to achieve optimal value

q_{i}^{1} = q_{i}^{0} + {({X_{i k}}^{T} X_{i k})}^{- 1} {X_{i k}}^{T} (T_{i}^{m} - T_{i}^{c} (q_{i}^{0}));

5th step, it is judged thatWhether meet convergence criterion

| \frac{q_{i}^{1} - q_{i}^{0}}{q_{i}^{1}} | < ϵ, i = 1, ..., 24;

ε=0.001, such as satisfied convergence, then substitutes into formula and obtains heat transfer coefficient h, terminate；

h_{i} = \frac{q_{i}^{1}}{T_{i}^{m} - T_{c W}}

As being unsatisfactory for convergence, then make

q_{i}^{0} = q_{i}^{1}, i = 1, ..., 24;

It is back to second step, until meeting till convergence gauge calculates h.

Proof procedure is as shown in Figure 4:

Experimentation is the temperature information being obtained cylinder body top layer discrete point by experiment, draws surface by inverse problem calculation Hot-fluid or the curve of temperature and distribution, we need to verify inverse problem model before the experiments, and simulation is by supposing Hot-fluid feature modeling goes out temperature field, extracts surface temperature discrete point information and is used as experimental temperature discrete points data, by rhetorical question Topic calculates surface heat flux value, compares calculating heat flow density and supposes heat flow density to verify that indirect problem dallies die change in time Type and the feasibility of program.

Input hot-fluid Annual distribution such as Fig. 5, substitutes into indirect problem program temperature value and calculates surface heat flow inverse value, Fig. 6 For all channel errors of all moment.It appeared that error is small, error mean rank is about 10^-14The order of magnitude, precision pole High.

It is last that it is noted that obviously above-described embodiment is only for clearly demonstrating example of the present invention, and also The non-restriction to embodiment.For those of ordinary skill in the field, can also do on the basis of the above description Go out change or the variation of other multi-form.Here without also cannot all of embodiment be given exhaustive.And thus drawn What Shen went out obviously changes or changes among still in protection scope of the present invention.

Claims

1. measuring an experimental technique for cyclical heat transmission coefficient, the method uses an experimental provision, and this device includes scalable The rotating cylinder, scalable spray angle and the nozzle of jetting height, be placed in the heater of drums inside, be embedded in rolling of rotating speed Thermocouple in cylinder cylinder, temperature collection device are electrically connected to thermocouple, and are exported by the temperature signal of thermocouple；

Specific experiment method comprises the following steps:

The first step: need to regulate the rotating speed of rotation cylinder according to test；According to the cooler environment of required simulation, regulate nozzle Jetting height and spray angle；Heater is utilized to heat rotating cylinder；

The each point for measuring temperature of cylinder is utilized to set up the method for mathematical Model of Heat Transfer as follows:

ρ c \frac{\partial T}{\partial t} = \frac{1}{r} \frac{\partial}{\partial r} (r λ \frac{\partial T}{\partial t}) + \frac{1}{r} \frac{\partial}{\partial θ} (\frac{λ}{r} \frac{\partial T}{\partial θ}) (r &Element; (s_{1}, s_{2}), θ &Element; [0, 2 π), t > 0)

Initial condition: T (r, 0)=T₀(r∈[s₁,s₂], t=0)

Boundary condition

\begin{matrix} T |_{r = s_{1}} = T_{f} (r = s_{1}, t > 0) & - λ \frac{\partial T}{\partial r} |_{r = s_{2}} = q (t), (r = s_{2}, t > 0) \end{matrix}

In formula: λ is cylinder heat conductivity, unit is w (m DEG C)^-1；ρ is cylinder density, and unit is Kg m^-3；C is cylinder Specific heat at constant pressure, unit is J (kg DEG C)^-1；T is temperature, and unit is DEG C；T is the moment, and unit is s；R is radial coordinate, single Position is mm；θ is circumferencial direction coordinate, and unit is radian；

According to heat balance principle, under unsteady state condition, enter the algebraical sum of the heat flow of cylinder any point p with heat-conducting mode Equal to its thermal change amount, the method setting up heat transfer discrete model is as follows:

\{\begin{matrix} \frac{λ (r_{P} - Δ r / 2)}{r_{P} {Δr}^{2}} T_{S}^{k + 1} + \frac{λ}{r_{P}^{2} {Δθ}^{2}} T_{W}^{k + 1} - (\frac{λ (r_{P} - Δ r / 2)}{r_{P} {Δr}^{2}} + \frac{2 λ}{r_{P}^{2} {Δθ}^{2}} + ρ c) T_{P}^{k + 1} + \frac{λ}{r_{P}^{2} {Δθ}^{2}} T_{E}^{k + 1} = - {ρcT}_{P}^{k} - \frac{q (r_{P} + Δ r / 2)}{r_{P} Δ r} \\ (m = 1) \\ \frac{λ (r_{P} - Δ r / 2)}{r_{P} {Δr}^{2}} T_{S}^{k + 1} + \frac{λ}{r_{P}^{2} {Δθ}^{2}} T_{W}^{k + 1} - (\frac{λ (r_{P} - Δ r / 2)}{r_{P} {Δr}^{2}} + \frac{2 λ}{r_{P}^{2} {Δθ}^{2}} + \frac{λ (r_{P} + Δ r / 2)}{r_{P} {Δr}^{2}} + ρ c) T_{P}^{k + 1} + \frac{λ}{r_{P}^{2} {Δθ}^{2}} T_{E}^{k + 1} + \frac{λ (r_{P} + Δ r / 2)}{r_{P} {Δr}^{2}} T_{N}^{k + 1} = - {ρcT}_{P}^{k} \\ (m = 2, 3, ..., N - 1) \\ \frac{λ}{r_{P}^{2} {Δθ}^{2}} T_{W}^{k + 1} + (\frac{λ (r_{P} - Δ r / 2)}{r_{P} {Δr}^{2} / 2} + \frac{2 λ}{r_{P}^{2} {Δθ}^{2}} + \frac{λ (r_{P} + Δ r / 2)}{r_{P} {Δr}^{2}} + ρ c) T_{P}^{k + 1} + \frac{λ}{r_{P}^{2} {Δθ}^{2}} T_{E}^{k + 1} + \frac{λ (r_{P} + Δ r / 2)}{r_{P} {Δr}^{2}} T_{N}^{k + 1} = - {ρcT}_{P}^{k} - \frac{λ (r_{P} - Δ r / 2)}{r_{P} {Δr}^{2} / 2} T_{f} \\ (m = N) \end{matrix}

M is the number of plies of cylinder any point p place grid；Temperature for k moment p point；The temperature value minute of the four direction of p point Wei T_W,T_E,T_S,T_N；r_PRadius for p point；Relevant parameter is substituted into above-mentioned solving equationsFrom And draw the temperature at the grid of thermocouple place

4th step, meter sensitivity coefficient X_ik, utilize the 3rd stepAnd temperature field Substitute into following formula and try to achieve sensitivity coefficient:

X_{i k} = \frac{\partial}{\partial q_{k}} (T_{i}^{c} (q_{k})) \approx \frac{T_{i}^{c} (q_{1}^{0} ..., q_{k}^{0} + {δq}_{k}^{0}, ... q_{n}^{0}) - T_{i}^{c} (q_{1}^{0} ..., q_{k}^{0}, ... q_{n}^{0})}{{δq}_{k}}

5th step, solvesFirst three step is utilized to obtainX_ikSubstitute into following formula and try to achieve optimal value

q_{i}^{1} = q_{i}^{0} + {({X_{i k}}^{T} X_{i k})}^{- 1} {X_{i k}}^{T} (T_{i}^{m} - T_{i}^{c} (q_{i}^{0})), (i = 1, ..., n)

6th step, it is judged thatWhether meet convergence criterion

| \frac{q_{i}^{1} - q_{i}^{0}}{q_{i}^{1}} | < ϵ, i = 1, ..., n;

Such as satisfied convergence, then substitute into following formula and obtain heat transfer coefficient h_i, terminate；

h_{i} = \frac{q_{i}^{1}}{T_{i}^{m} - T_{c W}}, i = 1, ..., n

As being unsatisfactory for convergence, then make

q_{i}^{0} = q_{i}^{1}, i = 1, ..., n;

Being back to second step, continue to solve, until meeting convergence, calculating h_iTill.

A kind of experimental technique measuring cyclical heat transmission coefficient the most as claimed in claim 1, the material of described rotation cylinder can To need corresponding selection according to test.

A kind of experimental technique measuring cyclical heat transmission coefficient the most as claimed in claim 1, ε < 0.001 in described 6th step.

A kind of experimental technique measuring cyclical heat transmission coefficient the most as claimed in claim 1, described temperature collection point number n= 24, temperature collection point distribution foundation is time step Δ τ=1s, spatial mesh size Δ θ=π/12, Δ r=1mm.