CN106156464A - The temperature rise calculation method of metalwork overcurrent and device - Google Patents

Abstract

The invention discloses temperature rise calculation method and the device of a kind of metalwork overcurrent, comprise determining that parameter, described parameter includes: by the current value of metalwork, the coefficient of heat transfer of described metalwork local environment, and the girth that the resistivity of described metalwork, specific heat capacity, density, cross-sectional area are corresponding with described cross-sectional area；According to Joule's law, specific heat capacity formula and Newton's law of cooling, and combine described parameter, calculate the temperature rise in the case of time long enough and in the default supervision time of the described metalwork overcurrent.The invention has the beneficial effects as follows: propose temperature rise calculation method and the device of a kind of metalwork overcurrent, thus metalwork is after galvanization uses and lasts different time, its temperature rise can be determined by calculating, and then be assessed the fitness that metalwork uses immediately.

Description

The temperature rise calculation method of metalwork overcurrent and device

Technical field

The present invention relates to lithium battery test applied technical field, be specifically related to the temperature rise of a kind of metalwork overcurrent Computational methods and device.

Background technology

Lithium ion battery (abbreviation lithium battery) has running voltage height, operating temperature width, long circulation life etc. Advantage, is used widely, and lithium battery was fast-developing as onboard power power supply the most in recent years. Lithium battery mainly by both positive and negative polarity active substance, electrolyte and prevent both positive and negative polarity short circuit barrier film form.Generally will Both positive and negative polarity active substance is coated in aluminum, copper foil current collector, then that barrier film is direct between both positive and negative polarity collector Make battery core by lamination or the mode that turns around, battery core is loaded rustless steel, aluminum hull or plastic housing, reinjects electricity Solve liquid-tight envelope and make square or cylindrical battery.

In the test and application process of lithium battery, such as when carrying out lithium battery combo, no matter inside battery or Person is between battery or battery is with outside, is required for metalwork as connecting line, is then electrified stream and carries out It is the most suitable to determine battery behavior and the metalwork used to test.

Metalwork will produce heat in the case of alive, i.e. occur that temperature raises phenomenon.But, raise Temperature would potentially result in serious consequence.Such as, for the lithium battery as vehicle power, it used Cheng Zhongxu supports different multiplying current discharge, and wherein internal battery core and extraneous conducting are to weld on collector The lug connect is connected with housing cover and is drawn, when electric current flows through cover plate due to cover plate by riveting pole Material selects difference, riveting gap etc. factor to affect cover plate pole heating when causing overcurrent, easily draws Play electric automobile security incident.

At present when carrying out lithium battery test, it is common that the temperature rise being empirically worth determines used metalwork Material, the most empirically determined possible temperature rise use Copper Foil as connecting line, and then determine battery Design whether meet and use requirement.But, this side determining metalwork according to the estimation of temperature rise empirical value Formula easily causes the wasting of resources, and manufacturing cost increases.

Summary of the invention

According to the first aspect of the invention, the present invention provides the temperature rise calculation method of a kind of metalwork overcurrent, Comprise determining that parameter, described parameter include: by the current value of metalwork, described metalwork local environment The coefficient of heat transfer, and the resistivity of described metalwork, specific heat capacity, density, cross-sectional area and described transversal The girth that area is corresponding；According to Joule's law, specific heat capacity formula and Newton's law of cooling, and combine described ginseng Number, calculates the temperature rise in the case of time long enough and in the default supervision time of the described metalwork overcurrent.

According to the second aspect of the invention, the present invention provides the temperature rise of a kind of metalwork overcurrent to calculate device, Including: parameter determination module, it is used for determining that parameter, described parameter include: by the current value of metalwork, The coefficient of heat transfer of described metalwork local environment, and the resistivity of described metalwork, specific heat capacity, density, The girth that cross-sectional area is corresponding with described cross-sectional area；Temperature rise computing module, for according to Joule's law, ratio Thermal capacitance formula and Newton's law of cooling, and combine described parameter, calculate described metalwork overcurrent at time foot Temperature rise in the case of enough length and in the default supervision time.

The invention has the beneficial effects as follows: propose temperature rise calculation method and the device of a kind of metalwork overcurrent, from And metalwork is after galvanization uses and lasts different time, its temperature rise can be determined by calculating, and then Assessed the fitness that metalwork uses immediately.

Detailed description of the invention

An embodiment of the present invention provides the temperature rise calculation method of a kind of metalwork overcurrent, and the method is according to Jiao Tumour of external auditory meatus rule, specific heat capacity formula and Newton's law of cooling, and combine law of conservation of energy, be determined by about The relevant parameter of metalwork determines temperature rise situation during metalwork overcurrent.

The energy Q1 (i.e. Joule's law) that in this embodiment, produced due to impedance by conductor according to electric current, (i.e. newton is cold for the energy Q3 that the chemical conversion heat energy Q2 (i.e. specific heat capacity formula) of conductor, exterior materials heat transfer are scattered and disappeared But law), draw three below equation:

Q₁=I²Rt,

Q₂=cm Δ T,

Q₃=KF Δ T^*t。

Wherein, I is the current value by metalwork, and R is the resistance of metalwork, and t is the time, and c is specific heat capacity, M is the quality of metalwork, and Δ T is temperature difference after metalwork overcurrent the most in the same time, i.e. Δ T=T_{Conductor temperature this moment}-T_{A moment temperature on conductor}, Δ T^*For the temperature after metalwork overcurrent and local environment Temperature difference, i.e. Δ T^*=T_{Conductor temperature this moment}-T_{Exterior materials temperature}, K is the coefficient of heat transfer, and F is heat exchange area.

According to law of conservation of energy, electric current is equal to change into by the energy that conductor produces due to impedance The energy sum that the heat energy of conductor and conductor and exterior materials heat transfer are scattered and disappeared, i.e. obtains following equation:

Q₁=Q₂+Q₃

Above-mentioned equation is substituted into above equation, obtains:

I²Rt=cm Δ T+KF Δ T^*t (1)

Due toF=C^*L, wherein, ρ_ResistivityFor the resistivity of metalwork, l For the length of metalwork, S is the cross-sectional area of metalwork, ρ_DensityFor the density of metalwork, C^*For metalwork Girth corresponding to cross-sectional area, substitute into formula (1), obtain:

Thus, in default supervision time t, metalwork by under constant current different time temperature rise (from Initial temperature starts) be:

Additionally, by formula (1) both sides simultaneously divided by time t, obtain:

$I^{2}R=\frac{\mathrm{Cm\ΔT}}{t}+\mathrm{KF\ΔT}*$

If imagination time t is sufficiently large,Can obtain following formula:

I²R=KF Δ T^*

Thus formula can be learnt: when time long enough, electric current by energy produced by object equal to scattering and disappearing Energy, conductor reaches thermal balance, and conductor temperature is constant unrelated with the time, and i.e. metalwork overcurrent is when calculating Between temperature rise in the case of long enough be

$\mathrm{\ΔT}*=\frac{I^{2}R}{\mathrm{KF}}$

To sum up, present embodiments provide a kind of very simple temperature rise calculating metalwork overcurrent accurately, keep away Exempt to estimate by empirical value the mode of temperature rise, and involved calculating be made without the data analysis of complexity, Have only to know used material includes the base attribute such as resistivity, specific heat capacity, can calculate exactly Go out the temperature rise value of metalwork, most important to the reliability of the use improving metalwork, and increase related application The reliability of design.

Additionally, based on preceding method embodiment, present invention also offers the temperature rise meter of a kind of metalwork overcurrent Calculate device, including:

Parameter determination module, is used for determining that parameter, described parameter include: by the current value of metalwork, institute State the coefficient of heat transfer of metalwork local environment, and the resistivity of described metalwork, specific heat capacity, density, horizontal stroke The girth that sectional area is corresponding with described cross-sectional area；

Temperature rise computing module, is used for according to Joule's law, specific heat capacity formula and Newton's law of cooling, and combines Described parameter, calculates described metalwork overcurrent in the case of time long enough and in the default supervision time Temperature rise.

The module related in this device implement the corresponding step referring to preceding method embodiment, at this Do not repeat.

It will be understood by those skilled in the art that in above-mentioned embodiment, all or part of step of various methods can Completing instructing related hardware by program, this program can be stored in a computer-readable recording medium, Storage medium may include that read only memory, random access memory, disk or CD etc..

Above content is to combine specific embodiment further description made for the present invention, it is impossible to recognize Determine the present invention be embodied as be confined to these explanations.Ordinary skill for the technical field of the invention For personnel, without departing from the inventive concept of the premise, it is also possible to make some simple deduction or replace.

Claims (7)

1. the temperature rise calculation method of a metalwork overcurrent, it is characterised in that including:

Determine that parameter, described parameter include: by the current value of metalwork, described metalwork local environment The coefficient of heat transfer, and the resistivity of described metalwork, specific heat capacity, density, cross-sectional area and described cross section Long-pending corresponding girth；

According to Joule's law, specific heat capacity formula and Newton's law of cooling, and combine described parameter, calculate described Temperature rise in the case of time long enough and in default supervision time during metalwork overcurrent.

2. the method for claim 1, it is characterised in that the calculating of described temperature rise includes:

The gross energy that electric current is produced is determined by described metalwork according to Joule's law；

Determine that electric current changes into the heat energy of described metalwork after passing through described metalwork according to specific heat capacity formula；

The lost energy that described metalwork scatters and disappears is determined with the heat transfer of described environment according to Newton's law of cooling；

According to law of conservation of energy, described gross energy is equal to described heat energy and described lost energy sum, in conjunction with Described parameter carries out the calculating of described temperature rise.

3. method as claimed in claim 2, it is characterised in that

The computing formula of described metalwork overcurrent temperature rise in the case of calculating time long enough is:

${\mathrm{\ΔT}}^{*}=\frac{I^{2}R}{\mathrm{KF}},$

Wherein, Δ T^*For the temperature rise of described metalwork overcurrent, I is described current value, F=C^*L, ρ_ResistivityFor described resistivity, l is the length of described metalwork, and S is described cross-sectional area, K For the described coefficient of heat transfer, C^*For described girth.

4. method as claimed in claim 2, it is characterised in that

The computing formula of described metalwork overcurrent temperature rise within the default supervision time is:

Wherein, Δ T is the temperature rise of described metalwork overcurrent, and I is described current value, ρ_ResistivityFor described resistance Rate, t is the described default supervision time, and C is described specific heat capacity, ρ_DensityFor described density, S is described transversal Area, K is the described coefficient of heat transfer, C^*For described girth.

5. the temperature rise of a metalwork overcurrent calculates device, it is characterised in that including:

Parameter determination module, is used for determining that parameter, described parameter include: by the current value of metalwork, institute State the coefficient of heat transfer of metalwork local environment, and the resistivity of described metalwork, specific heat capacity, density, horizontal stroke The girth that sectional area is corresponding with described cross-sectional area；

Temperature rise computing module, is used for according to Joule's law, specific heat capacity formula and Newton's law of cooling, and combines Described parameter, calculates described metalwork overcurrent in the case of time long enough and in the default supervision time Temperature rise.

6. device as claimed in claim 5, it is characterised in that

The computing formula of described metalwork overcurrent temperature rise in the case of calculating time long enough is:

${\mathrm{\ΔT}}^{*}=\frac{I^{2}R}{\mathrm{KF}},$

Wherein, Δ T^*For the temperature rise of described metalwork overcurrent, I is described current value, F=C^*L, ρ_ResistivityFor described resistivity, l is the length of described metalwork, and S is described cross-sectional area, K For the described coefficient of heat transfer, C^*For described girth.

7. device as claimed in claim 5, it is characterised in that

The computing formula of described metalwork overcurrent temperature rise within the default supervision time is:

Wherein, Δ T is the temperature rise of described metalwork overcurrent, and I is described current value, ρ_ResistivityFor described resistance Rate, t is the described default supervision time, and C is described specific heat capacity, ρ_DensityFor described density, S is described transversal Area, K is the described coefficient of heat transfer, C^*For described girth.