The experimental installation for identification of coefficient of heat conductivity of the wood that models the running of processes similar to operating conditions of devices for pyrolysis of wood is offered. The description of installation elements and their functional purpose is given. The dependence of coefficient of heat conductivity of a pine on temperature expressed in polar coordinates is received

Mironov, A.

Saipov, A.

Satayev, M.

Ved, V. E.

Electronic National Technical University &quot;Kharkiv Polytechnic Institute&quot; Institutional Repository (eNTUKhPIIR)

Ved V., Satayev M., Mironov A., Saipov A. Installation for Identification of Heat Conductivity Coefficient of Wood   Industrial Technology and Engineering. 2016, 2(19): 31-35 31  INSTALLATION FOR IDENTIFICATION OF HEAT CONDUCTIVITY COEFFICIENT OF WOOD  Ved V.1, Satayev M.2, Mironov A.1, Saipov A.2  1 National Technical University “Kharkiv Polytechnic Institute” 2 M.Auezov South Kazakhstan State University, Shymkent, Kazakhstan  E-mail: valeriy.e.ved@gmail.com  ABSTRACT   The experimental installation for identification of coefficient of heat conductivity of the wood that models the running of processes similar to operating conditions of devices for pyrolysis of wood is offered. The description of installation elements and their functional purpose is given. The dependence of coefficient of heat conductivity of a pine on temperature expressed in polar coordinates is received.  INTRODUCTION  Development of production of charcoal by a pyrolysis method requires improvement of technology at all stages. To have the process of pyrolysis to be most productive and energy efficient, it is necessary to operate with value of coefficient of heat conductivity for wood raw materials of each breed. Uniqueness of the offered installation is in the use of a known method of determination of heat conductivity coefficient of solid bodies in industry [1,2]. The installation allows taking into account not only the nonlinear dependence of heat conductivity coefficient of wood on temperature with its increase till 600 °C, but also anisotropy of heat-conducting capacity of a material [3]. Determination of coefficient of heat conductivity of wood as a function of its breed and temperature will allow to use most reasonably the required amount of energy at each stage of production of pyrolysis products. It will cause economy of energy and, as a result, essential reduction of the enterprise expenses connected with losses of heat [4]. Besides, reduction of waste emissions from use of fuel during production will favorably affect an ecological component of technology [5]. It is obvious that the value of coefficient of wood heat conductivity has to correlate with the value of temperature at which this parameter is defined. Due to features of pyrolysis process the coefficient of wood heat conductivity can change even in isothermal conditions since wood is continuously transformed with removal of volatile components from its structure. Different breeds of a tree have individual thermal properties due to the structure of wood [6] therefore their behavior at heating to high temperatures cannot be the same for all considered  breeds (even for similar types of wood from the botany point of view). Ved V., Satayev M., Mironov A., Saipov A. Installation for Identification of Heat Conductivity Coefficient of Wood   32 Industrial Technology and Engineering. 2016, 2(19): 31-35  For correct determination of temperature dependence of thermal conductivities of wood it is necessary to neglect the geometry of the body during heat transfer through the body whose heat conductivity is measured. Such problem is solved by using methods of mathematical modeling and the corresponding algorithms of indirect searching of magnitudes.  Statement of experiment objectives For studying the heat-conducting capacity of wood during pyrolysis it is necessary to create the corresponding experimental installation. The analysis of the existing installations showed that the most suitable method for determination of heat conductivity of materials [7-9] is the method of creation of a radial heat flux. This method requires the use of wood sample of a cylindrical form 70 mm high, external diameter of 64 mm and internal – 10 mm. Around the sample the ceramic heater of block type creates the heat flux directed from the periphery of the cylinder to its center where by pumping of a cooling liquid through a copper tube a sink of the heat that travelled through the wood sample. The temperature difference of a coolant at an input and exit of the installation is determined by signals of thermocouples (see below) and corresponds to the amount of heat that passed through a wood sample during a particular time interval of measurements. By variation of the amount of heat it is possible to change the inside temperature of the sample. The fullest transfer of heat to the  surface of the heat receiving objects is provided at their side-by-side contact with the heat generating elements. For this purpose the ceramic heaters of contact type were manufactured using the original technology [10] and mounted by high-temperature heat-transmitting glues on external surfaces of wood samples. The heat flux produced by heaters passes through the body of the sample and creates in it a temperature field. Temperatures are fixed in the volume of a cylindrical sample along and across of fibers, as shown in Fig. 1, by means of thermocouples in a quartz braid with a diameter of 0,1 mm of graduation of THA. Thermocouples were placed at the distance of 35 mm from a face surface and at the distances of 14, 23 and 32 mm from the sample axis. Thermocouples 1-3 were placed along wood fibers, and 4–6  were placed perpendicular to the first three ones (Fig. 1).     Fig. 1. Placement of thermocouples in a wood sample relative to fibers  Ved V., Satayev M., Mironov A., Saipov A. Installation for Identification of Heat Conductivity Coefficient of Wood   Industrial Technology and Engineering. 2016, 2(19): 31-35 33    Fig. 2. Conditional scheme of experimental installation: C1 – the initial capacitance, C2 – capacitance for collecting water, TC – the thermal camera, STC – a set of thermocouples, CTI – the converter of thermometric information, PC – the personal computer.  In the center of each cylinder made from the breed of a tree being studied along its vertical axis there is a hollow channel with a copper tube embedded in it through which water is pumped over. Water discharge is determined by means of rotameters and is regulated by stop valves.  Description of elements of experimental installation Installation for determination of coefficient of heat conductivity of wood includes (Fig. 2): the thermal chamber, two vessels for water, connecting tubes, a set of nine thermocouples, the device for processing thermometric information that transmits signals to the personal computer. The thermal chamber consists of the following elements (Fig. 3): a copper tube (a), the studied sample in the form of the wooden cylinder (b), the heater of a block type (c), a double layer of thermal isolation (d), the MKRV-200 felt with the aluminum foil pasted on its external surface and the case made of the polished foil 0,15 mm thick of an alloy 20X80H (e) Ved V., Satayev M., Mironov A., Saipov A. Installation for Identification of Heat Conductivity Coefficient of Wood   34 Industrial Technology and Engineering. 2016, 2(19): 31-35  and the joints in the case are sealed by a high-temperature silicone germet (for simplicity in the picture the top and lower covers of the case isolated is the same way aren't shown).    Fig. 3. Elements of the thermal chamber: a) the copper tube, b) the sample, c) the block of heaters from current outputs, d) two-layer thermal isolation, e) case  The block of heaters (Fig. 3, c) is made of four ceramic heaters of cylindrical shape connected in series with their external surface covered by the thin layer of a silicone reflecting a radiant component of a heat flux into object being studied [11]. To minimize the thermal losses of the block of heaters due to its heat conductivity and radiant energy emission into its environment, the two-layer thermal isolation (Fig. 3, d), skintight both to external and to face surfaces is used. The case of the thermal chamber (Fig. 4, e) is made with a maximum level of sealing for creation of the conditions corresponding to that in wood pyrolysis devices. The cut of the thermal chamber ready for use  is given in Fig. 4.    Fig. 4. The thermal chamber in cut  Except the thermocouples located directly in the studied wood sample in the thermal chamber there is also a thermocouple that measures temperature in an isolation layer. The registering equipment, as a part of the converter of a signal, the power secondary device and the personal computer, fixes changes during the operation of installation per Ved V., Satayev M., Mironov A., Saipov A. Installation for Identification of Heat Conductivity Coefficient of Wood   Industrial Technology and Engineering. 2016, 2(19): 31-35 35  identical periods of time. These data correlate with the heater power for each temperature and time intervals. With the help of this installation the temperature dependences of a cylindrical sample of a pine have been studied and after the corresponding mathematical processing of these data the following dependences of the coefficient of heat conductivity on temperature expressed in polar coordinates have been received:   CONCLUSION  The experimental installation is developed for identification of coefficient of heat conductivity of wood in the range of temperatures up to 600oC. The installation models the processes similar to functioning conditions of devices of wood pyrolysis. The description of design elements of installation and their functional purpose is given. The dependences of coefficient of heat conductivity of a pine on temperature expressed in polar coordinates are received.  REFERENCES  1 Copyright certificate of the USSR No. 127846, C. G01N25/18, 1960. 2 Copyright certificate of the USSR No. 613232, C. G01N1/18, 1978. 3 Patent for the useful model UA No. 103355, C. G01N25/18, 2015. 4 Ved V. E. Evaluation of energy expenditure on drying process of wood raw materials / Ved V. E., Mironov A.N., Rovensky O.I.. Quarterly scientific and practical journal "The Integrated Technologies and Energy Saving", 2014, no. 4, pp. 34-37. 5 Ved V. E. Modern problems of charcoal-burning and pyrolysis of wood / Ved V. E., Mironov A.N. The Bulletin NTU "KhPI", 2014, no. 49, pp. 88-95. 6 Ved V. E. Study of relationship between structure of wood and kinetics of its drying process / Ved V. E., Mironov A.N. The Bulletin NTU "KhPI", 2015, No. 44 (1153), pp. 47-51. 7 Copyright certificate No. 1557502, C. G01N25/18, 1990. 8 Copyright certificate No. 1821703, C. G01N25/18, 1993. 9 Patent for the invention RU No. 2289126, C. G01N25/32, 2006. 10 Ved V. E.. Ceramic heaters for the power effective directed transfer of heat / Ved V. E., Tovazhnyansky L.L., Guseva N. I., Verba A.G. International information and technical journal "Equipment. Tool". For professionals, 2006, no. 3, pp. 96-98. 11 Ved V. E. Technology of stationary heating of pump and compressor pipes by thermoelectroelements for the purpose of elimination of paraffin deposits / Ved V. E., Khodakovsky V. Yu., Magasevich V. I. Collection of scientific works of the Ukrainian research institute of natural gases UkrScRIGas "Questions of development of the gas industry of Ukraine". Kharkov, 2001, Issue XXIX, pp. 258-261. 

Installation for identification of heat conductivity coefficient of wood

Library of National Technical University "Kharkiv Polytechnic Institute"

Ved V., Satayev M., Mironov A., Saipov A. Installation for Identification of Heat Conductivity Coefficient of 
Wood 
 
 
Industrial Technology and Engineering. 2016, 2(19): 31-35 31 
 
INSTALLATION FOR IDENTIFICATION OF HEAT CONDUCTIVITY 
COEFFICIENT OF WOOD 
 
Ved V.
1
, Satayev M.
2
, Mironov A.
1
, Saipov A.
2
 
 
1
 National Technical University “Kharkiv Polytechnic Institute” 
2
 M.Auezov South Kazakhstan State University, Shymkent, Kazakhstan 
 
E-mail: valeriy.e.ved@gmail.com 
 
ABSTRACT  
 
The experimental installation for identification of coefficient of heat conductivity of the 
wood that models the running of processes similar to operating conditions of devices for 
pyrolysis of wood is offered. The description of installation elements and their functional 
purpose is given. The dependence of coefficient of heat conductivity of a pine on temperature 
expressed in polar coordinates is received. 
 
INTRODUCTION 
 
Development of production of charcoal by a pyrolysis method requires improvement of 
technology at all stages. To have the process of pyrolysis to be most productive and energy 
efficient, it is necessary to operate with value of coefficient of heat conductivity for wood raw 
materials of each breed. Uniqueness of the offered installation is in the use of a known 
method of determination of heat conductivity coefficient of solid bodies in industry [1,2]. The 
installation allows taking into account not only the nonlinear dependence of heat conductivity 
coefficient of wood on temperature with its increase till 600 °C, but also anisotropy of heat-
conducting capacity of a material [3]. 
Determination of coefficient of heat conductivity of wood as a function of its breed and 
temperature will allow to use most reasonably the required amount of energy at each stage of 
production of pyrolysis products. It will cause economy of energy and, as a result, essential 
reduction of the enterprise expenses connected with losses of heat [4]. Besides, reduction of 
waste emissions from use of fuel during production will favorably affect an ecological 
component of technology [5]. 
It is obvious that the value of coefficient of wood heat conductivity has to correlate with 
the value of temperature at which this parameter is defined. Due to features of pyrolysis 
process the coefficient of wood heat conductivity can change even in isothermal conditions 
since wood is continuously transformed with removal of volatile components from its 
structure. 
Different breeds of a tree have individual thermal properties due to the structure of 
wood [6] therefore their behavior at heating to high temperatures cannot be the same for all 
considered  breeds (even for similar types of wood from the botany point of view). 
Ved V., Satayev M., Mironov A., Saipov A. Installation for Identification of Heat Conductivity Coefficient of 
Wood 
 
 
32 Industrial Technology and Engineering. 2016, 2(19): 31-35 
 
For correct determination of temperature dependence of thermal conductivities of wood 
it is necessary to neglect the geometry of the body during heat transfer through the body 
whose heat conductivity is measured. Such problem is solved by using methods of 
mathematical modeling and the corresponding algorithms of indirect searching of magnitudes. 
 
Statement of experiment objectives 
For studying the heat-conducting capacity of wood during pyrolysis it is necessary to 
create the corresponding experimental installation. 
The analysis of the existing installations showed that the most suitable method for 
determination of heat conductivity of materials [7-9] is the method of creation of a radial heat 
flux. This method requires the use of wood sample of a cylindrical form 70 mm high, external 
diameter of 64 mm and internal – 10 mm. 
Around the sample the ceramic heater of block type creates the heat flux directed from 
the periphery of the cylinder to its center where by pumping of a cooling liquid through a 
copper tube a sink of the heat that travelled through the wood sample. 
The temperature difference of a coolant at an input and exit of the installation is 
determined by signals of thermocouples (see below) and corresponds to the amount of heat 
that passed through a wood sample during a particular time interval of measurements. By 
variation of the amount of heat it is possible to change the inside temperature of the sample. 
The fullest transfer of heat to the  surface of the heat receiving objects is provided at their 
side-by-side contact with the heat generating elements. For this purpose the ceramic heaters of 
contact type were manufactured using the original technology [10] and mounted by high-
temperature heat-transmitting glues on external surfaces of wood samples. The heat flux 
produced by heaters passes through the body of the sample and creates in it a temperature 
field. Temperatures are fixed in the volume of a cylindrical sample along and across of fibers, 
as shown in Fig. 1, by means of thermocouples in a quartz braid with a diameter of 0,1 mm of 
graduation of THA. Thermocouples were placed at the distance of 35 mm from a face surface 
and at the distances of 14, 23 and 32 mm from the sample axis. Thermocouples 1-3 were 
placed along wood fibers, and 4–6  were placed perpendicular to the first three ones (Fig. 1).  
 
 
 
Fig. 1. Placement of thermocouples in a wood sample relative to fibers 
 
Ved V., Satayev M., Mironov A., Saipov A. Installation for Identification of Heat Conductivity Coefficient of 
Wood 
 
 
Industrial Technology and Engineering. 2016, 2(19): 31-35 33 
 
 
 
Fig. 2. Conditional scheme of experimental installation: 
C1 – the initial capacitance, C2 – capacitance for collecting water, TC – the thermal camera, 
STC – a set of thermocouples, CTI – the converter of thermometric information, PC – the 
personal computer. 
 
In the center of each cylinder made from the breed of a tree being studied along its 
vertical axis there is a hollow channel with a copper tube embedded in it through which water 
is pumped over. Water discharge is determined by means of rotameters and is regulated by 
stop valves. 
 
Description of elements of experimental installation 
Installation for determination of coefficient of heat conductivity of wood includes (Fig. 
2): the thermal chamber, two vessels for water, connecting tubes, a set of nine thermocouples, 
the device for processing thermometric information that transmits signals to the personal 
computer. 
The thermal chamber consists of the following elements (Fig. 3): a copper tube (a), the 
studied sample in the form of the wooden cylinder (b), the heater of a block type (c), a double 
layer of thermal isolation (d), the MKRV-200 felt with the aluminum foil pasted on its 
external surface and the case made of the polished foil 0,15 mm thick of an alloy 20X80H (e) 
Ved V., Satayev M., Mironov A., Saipov A. Installation for Identification of Heat Conductivity Coefficient of 
Wood 
 
 
34 Industrial Technology and Engineering. 2016, 2(19): 31-35 
 
and the joints in the case are sealed by a high-temperature silicone germet (for simplicity in 
the picture the top and lower covers of the case isolated is the same way aren't shown). 
 
 
 
Fig. 3. Elements of the thermal chamber: 
a) the copper tube, b) the sample, c) the block of heaters from current outputs, 
d) two-layer thermal isolation, e) case 
 
The block of heaters (Fig. 3, c) is made of four ceramic heaters of cylindrical shape 
connected in series with their external surface covered by the thin layer of a silicone reflecting 
a radiant component of a heat flux into object being studied [11]. 
To minimize the thermal losses of the block of heaters due to its heat conductivity and 
radiant energy emission into its environment, the two-layer thermal isolation (Fig. 3, d), 
skintight both to external and to face surfaces is used. 
The case of the thermal chamber (Fig. 4, e) is made with a maximum level of sealing for 
creation of the conditions corresponding to that in wood pyrolysis devices. 
The cut of the thermal chamber ready for use  is given in Fig. 4. 
 
 
 
Fig. 4. The thermal chamber in cut 
 
Except the thermocouples located directly in the studied wood sample in the thermal 
chamber there is also a thermocouple that measures temperature in an isolation layer. 
The registering equipment, as a part of the converter of a signal, the power secondary 
device and the personal computer, fixes changes during the operation of installation per 
Ved V., Satayev M., Mironov A., Saipov A. Installation for Identification of Heat Conductivity Coefficient of 
Wood 
 
 
Industrial Technology and Engineering. 2016, 2(19): 31-35 35 
 
identical periods of time. These data correlate with the heater power for each temperature and 
time intervals. 
With the help of this installation the temperature dependences of a cylindrical sample of 
a pine have been studied and after the corresponding mathematical processing of these data 
the following dependences of the coefficient of heat conductivity on temperature expressed in 
polar coordinates have been received: 
  
CONCLUSION 
 
The experimental installation is developed for identification of coefficient of heat 
conductivity of wood in the range of temperatures up to 600oC. The installation models the 
processes similar to functioning conditions of devices of wood pyrolysis. The description of 
design elements of installation and their functional purpose is given. The dependences of 
coefficient of heat conductivity of a pine on temperature expressed in polar coordinates are 
received. 
 
REFERENCES 
 
1 Copyright certificate of the USSR No. 127846, C. G01N25/18, 1960. 
2 Copyright certificate of the USSR No. 613232, C. G01N1/18, 1978. 
3 Patent for the useful model UA No. 103355, C. G01N25/18, 2015. 
4 Ved V. E. Evaluation of energy expenditure on drying process of wood raw materials / Ved 
V. E., Mironov A.N., Rovensky O.I.. Quarterly scientific and practical journal "The 
Integrated Technologies and Energy Saving", 2014, no. 4, pp. 34-37. 
5 Ved V. E. Modern problems of charcoal-burning and pyrolysis of wood / Ved V. E., 
Mironov A.N. The Bulletin NTU "KhPI", 2014, no. 49, pp. 88-95. 
6 Ved V. E. Study of relationship between structure of wood and kinetics of its drying process 
/ Ved V. E., Mironov A.N. The Bulletin NTU "KhPI", 2015, No. 44 (1153), pp. 47-51. 
7 Copyright certificate No. 1557502, C. G01N25/18, 1990. 
8 Copyright certificate No. 1821703, C. G01N25/18, 1993. 
9 Patent for the invention RU No. 2289126, C. G01N25/32, 2006. 
10 Ved V. E.. Ceramic heaters for the power effective directed transfer of heat / Ved V. E., 
Tovazhnyansky L.L., Guseva N. I., Verba A.G. International information and technical 
journal "Equipment. Tool". For professionals, 2006, no. 3, pp. 96-98. 
11 Ved V. E. Technology of stationary heating of pump and compressor pipes by 
thermoelectroelements for the purpose of elimination of paraffin deposits / Ved V. E., 
Khodakovsky V. Yu., Magasevich V. I. Collection of scientific works of the Ukrainian 
research institute of natural gases UkrScRIGas "Questions of development of the gas industry 
of Ukraine". Kharkov, 2001, Issue XXIX, pp. 258-261. 


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Installation for identification of heat conductivity coefficient of wood

Abstract

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Electronic National Technical University "Kharkiv Polytechnic Institute" Institutional Repository (eNTUKhPIIR)

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Installation for identification of heat conductivity coefficient of wood

Abstract

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Full text

Available Versions

Electronic National Technical University &quot;Kharkiv Polytechnic Institute&quot; Institutional Repository (eNTUKhPIIR)

Library of National Technical University "Kharkiv Polytechnic Institute"

Electronic National Technical University "Kharkiv Polytechnic Institute" Institutional Repository (eNTUKhPIIR)