DESC:FIELD OF THE INVENTION:
This invention relates to the field of thermal engineering.

Particularly, this invention relates to an apparatus to determine thermal conductivity of volatile liquids

BACKGROUND OF THE INVENTION:
The thermal conductivity of a material is a measure of its ability to conduct heat.

There are a number of possible ways to measure thermal conductivity, each of them suitable for a limited range of materials, depending on the thermal properties and the medium temperature.

Most of the prior art apparatus, for measurement of thermal conductivity of liquids, involve heating from one end and cooling from the other end in order to cause heat transfer through the specimen. These methods face problems when the specimen is a volatile liquid. Due to heating involved in their setups, evaporation and bubble formation of volatile measurement leads to erroneous result/s and it may also be unsafe in cases where a highly volatile liquid fuel is used as a specimen.

Besides this problem, many of the prior art apparatus, which are generally found in college laboratories, need to achieve steady state of heat transfer which requires longer time (generally in the order of 150 minutes) for experimentation.

Prior art, transient-state-based, apparatus which, mostly, do not face the above problems are very expensive as they need highly sophisticated instrumentation data, processing sensors, and the like elements.

Prior art apparatus gives thermal conductivity at only one temperature in a single experiment; thus, measurement of thermal conductivity, at different temperatures, require stabilizing the specimen at a temperature and conducting experiments those many times which is time consuming.

Therefore, there is a need for an economical and good solution.

OBJECTS OF THE INVENTION:
An object of the invention is to provide an apparatus which measures thermal conductivity.

Another object of the invention is to provide an apparatus which measures thermal conductivity of volatile liquids.

Another object of the invention is to provide an economical apparatus which measures thermal conductivity; obviating the need to use highly sophisticated instrumentation data, processing sensors, and the like elements.

Yet another object of the invention is to avoid problems of evaporation of volatile specimen during experimentation to determine thermal conductivity of the specimen.

SUMMARY OF THE INVENTION:
According to this invention, there is provided an apparatus to determine thermal conductivity of volatile liquids, said apparatus comprising:
a liquid cooling system consisting, essentially of,
a specimen cooling block configured to hold specimen liquid to be cooled with coolers; and
a coupled water circulation block in order to create a continuous flow of water for said system, said liquid cooling system configured to hold liquid to be cooled,
a first temperature sensor configured to measure temperature of said specimen in said specimen cooling block;
said liquid cooling system, along with said cooler, being provisioned in an inclined manner so as to natural convection of specimen liquid for faster cooling and to be able to drain the specimen by gravity;
a spherical shell assembly consisting, essentially of,
a spherical shell configured to receive said specimen from said a specimen cooling block;
temperature sensors in order to measure temperature of said specimen, at a core of said assembly and an inner surface of said assembly, in order to compute thermal conductivity of said test specimen;
a capillary connected to said spherical shell in order to inject said specimen into said spherical shell in order to give minimal contact to the spherical shell area and in order to minimize heat transfer through said capillary;
a data handling unit consisting, essentially of,
data handling unit configured to receive temperature data from said first sensor in order to determine when to stop cooling, said second sensor in order to determine thermal conductivity of said specimen, said third sensor in order to determine thermal conductivity of said specimen.

In at least an embodiment, said coolers are Peltier coolers.

In at least an embodiment, said water circulation block being mounted on a heat sink to assist removal of heat in order to cool said liquid held in said cooling block.

In at least an embodiment, said liquid cooling system comprising a pump configured to pump water in order to create a continuous flow of water through said water circulation Block.

In at least an embodiment, said cooling block being a cuboidal shape made of high thermal conductivity material for faster heat removal from the liquid specimen and being insulated from the surrounding to minimize heat ingress to the test specimen.

In at least an embodiment, said cooling block having various ports and outlets, in that, being provisioned:
a port to inject / transfer said specimen into said cooling block;
a port to insert a first temperature Sensor in said cooling block for said specimen cooling temperature measurement;
an outlet connected to a direction control valve for injecting said specimen to said spherical shell; and
an outlet connected to a drain valve to drain said specimen out of said cooling block.

In at least an embodiment, said temperature sensors being a second temperature sensor and a third temperature sensor.

In at least an embodiment, said apparatus comprising a tube being a Temperature Sensor Guide in order to provide rigid support to said spherical shell assembly and in order to enable insertion of said temperature sensors into said spherical shell.

In at least an embodiment, a direction control valve is configured between said specimen cooling block and said spherical shell in order to control the direction of transfer of the test specimen between said specimen cooling block and said spherical shell, in that, said direction control valve being a 3-way direction control valve such that:
a first tube, connected to said 3-way direction control valve, being used to connect to said specimen cooling block;
a second tube, connected to said 3-way direction control valve, being used to connect to a specimen injector; and
a third tube, connected to said 3-way direction control valve, being used to connect to said spherical shell.
such that said direction control valve being configured to connect any two paths at a time, while blocking a third path.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS:
The invention will now be described in relation to the accompanying drawings, in which:
FIGURE 1 illustrates an isometric view of the apparatus of this invention;
FIGURE 2 illustrates a front view of the apparatus of this invention;
FIGURE 3 illustrates a top view of the apparatus of this invention;
FIGURE 4a illustrates test specimen cooling arrangement (Front View;
FIGURE 4b illustrates test specimen cooling arrangement (Top View); and
FIGURE 5 illustrates spherical shell assembly with Temperature Sensor 2 (17) and Temperature Sensor 3 (18).

DETAILED DESCRIPTION OF THE ACCOMPANYING DRAWINGS:
According to this invention, there is provided an apparatus to determine thermal conductivity of volatile liquids.

FIGURE 1 illustrates an isometric view of the apparatus of this invention.
FIGURE 2 illustrates a front view of the apparatus of this invention.
FIGURE 3 illustrates a top view of the apparatus of this invention.
FIGURE 4a illustrates test specimen cooling arrangement (Front View).
FIGURE 4b illustrates test specimen cooling arrangement (Top View).
FIGURE 5 illustrates spherical shell assembly with Temperature Sensor 2 (17) and Temperature Sensor 3 (18).

In at least an embodiment, the apparatus, of this invention, comprises a liquid cooling system. The function of Liquid Cooling System is to store and cool the (liquid) test specimen to the required cooling temperature.
In at least an embodiment of the liquid cooling system, the following components are provided:
Peltier Coolers: Peltier Coolers (1) are used to cool the test specimen to required temperature. However, other methods of cooling may also be applicable.
Power Supply Unit: The Peltier Coolers (1) are powered by a Power Supply Unit (2).
Water Circulation Block: While the Peltier Coolers (1) remove heat at their cold surface, they need to reject heat at the opposite hot surface. The Peltier Coolers (1) work more efficiently when heat is rejected at faster rate from the hot surface. Therefore, a Water Circulation Block (3) is used to remove the heat from hot surface of the Peltier Coolers (1) by forced water cooling. However, other arrangements such as a heat sink for air cooling may also be possible.
Heat Sink: The Water Circulation Block (3) is mounted on a Heat Sink (4) to assist removal of heat.
Pump: To create a continuous flow of water through the Water Circulation Block (3), a water Pump (5) is used.
Water Container: The Pump (5) circulates water in a closed loop such that it draws water from a Water Container (6), circulates it through the Water Circulation Block (3), and the water goes back to the Water Container (6).
Specimen Cooling Block: Mounted over the Peltier Coolers (1) is the Specimen Cooling Block (7) to hold the specimen for cooling. It is made of high thermal conductivity material for faster heat removal from the liquid specimen. It is insulated from the surrounding to minimize heat ingress to the test specimen. A cuboidal design is made such that the Specimen Cooling Block (7) has larger area in contact with the cooling surface of the Peltier Coolers (1). An inclined arrangement of the Specimen Cooling Block (7), Peltier Coolers (1) and the Water Circulation Block (3) is made so as to achieve natural convection of specimen for faster cooling and to be able to drain the specimen by gravity. The Specimen Cooling Block (7) has ports and outlets for various functions:
A port to inject / transfer the specimen in the Specimen Cooling Block (7).
A port to insert Temperature Sensor 1 (16) in the Specimen Cooling Block (7) for the specimen cooling temperature measurement.
An outlet connected to a Direction Control Valve (DCV) (8) for injecting the specimen to a Spherical Shell (13).
An outlet connected to a Drain Valve (9) to drain the test specimen out of the Specimen Cooling Block (7).

In at least an embodiment, the apparatus, of this invention, comprises a liquid injection and drain arrangement. The liquid injection and drain arrangement comprises the following components to handle and control the test specimen flow between the specimen cooling block and the spherical shell.
In at least an embodiment of the liquid injection and drain arrangement, the following components are provided:
Direction Control Valve (DCV): In order to control the direction of transfer of the test specimen between the Specimen Cooling Block (7) and the Spherical Shell (13) using a Specimen Injector (10), a 3-way DCV (8) is used. There are three Tubing (11) that connect to the DCV (8), one from the Specimen Cooling Block (7), second from the Specimen Injector (10) and third from the Spherical Shell (13). The DCV (8) can connect any two paths at a time, while blocking the third.
Drain Valve: It connects to the Specimen Cooling Block (7) outlet and used to drain the test specimen after completion of test.
Specimen Injector: It is used to transfer (draw and inject) the test specimen between the Specimen Cooling Block (7) and the Spherical Shell (13).
Tubing: To carry the test specimen between different parts of the apparatus.
Drain Box: There is a Drain Box (12) to collect the drained test specimen after completion of test.

In at least an embodiment, the apparatus, of this invention, comprises a spherical shell assembly.
In at least an embodiment of the spherical shell assembly (13), the following components are provided:
Spherical Shell: A Spherical Shell (13) is used, which is made of high thermal conductivity material and thin walls for negligible wall thermal resistance (as per the assumption from the mathematical model). Temperature Sensor 2 (17) and Temperature Sensor 3 (18) are used to measure the test specimen temperature at the core and the inner surface of the Spherical Shell (13) respectively, which are used in the mathematical model to calculate thermal conductivity of the test specimen (note that the mathematical model uses outer surface of spherical mass of liquid, which can be obtained by measuring the temperature at inner surface of the Spherical Shell, therefore, temperature at the inner surface of Spherical Shell (13) is measured)
Capillary: A Capillary (14) is connected to the Spherical Shell (13) to inject the test specimen into the Spherical Shell (13). A Capillary (14) is used as it gives minimal contact to the Spherical Shell (13) area, to minimize the heat transfer through the Capillary (14) (thus minimizing the errors due conduction through the Capillary (14) walls)
Temperature Sensor Guide: To insert the Temperature Sensor 2 (17) and Temperature Sensor 3 (18) into the Spherical Shell (13) for temperature measurement at the core and surface of the Spherical Shell (13) respectively, a tube is used as Temperature Sensor Guide (15). The Temperature Sensor Guide (15) also provides rigid support to the Spherical Shell (13) Assembly.

In at least an embodiment, the apparatus, of this invention, comprises a data handling unit. This unit functions to collect the temperature data, process the data and display various inputs for the operator of the apparatus and to display the experimental thermal conductivity value.
In at least an embodiment of data handling unit, the following components are provided:
Temperature Sensor 1: To measure the temperature of specimen in the Specimen Cooling Block (7). This indicates when required cooling temperature is achieved and the cooling needs to stop.
Temperature Sensor 2: To measure the temperature at the core of the Spherical Shell (13). Its temperature is used in the mathematical model to calculate thermal conductivity of the test specimen.
Temperature Sensor 3: To measure the temperature at the inner surface of the Spherical Shell (13). This temperature is used in the mathematical model to calculate thermal conductivity of the test specimen.
Data Processor and Display: Data from the Temperature Sensor 1 (16), Temperature Sensor 2 (17) and Temperature Sensor 3 (18) is given to a Data Processor and Display (19) unit. This unit may perform functions as below
Display the specimen temperature on a Display while cooling
Indication when specimen is cooled to the required temperature
Indication when the specimen completely fills the Spherical Shell (13) while Injection
Recording the core and inner surface temperature data with time
Calculate thermal conductivity from the collected data and display its value on the Display.

In at least an embodiment, the apparatus, of this invention, comprises a structural unit.
In at least an embodiment of structural unit, the following components are provided:
Base Frame: A Base Frame (20) provides structural support and rigidity to the apparatus.
Test Chamber: A Test Chamber (21) encloses the Spherical Shell (13) Assembly to avoid effects of external air movements and maintain stable natural convection of air around the Spherical Shell (13).

WORKING OF THE APPARATUS:
Below steps show the working of the apparatus to determine thermal conductivity of a liquid test specimen.
Test specimen is transferred to the Specimen Cooling Block (7).
Data Processor and Display (19) is turned ON to display Temperature Sensor 1 (16), Temperature Sensor 2 (17) and Temperature Sensor 3 (18) temperatures.
Power Supply Unit (2) is turned on to Operate the Peltier Coolers (1) and the Pump (5).
Temperature is monitored for the Temperature Sensor 1 (16) in the Specimen Cooling Block (7). Cooling is stopped when the test specimen temperature reaches to a required value.
The DCV (8) is operated to connect the Specimen Cooling Block (7) and the Specimen Injector (10) paths, while blocking the Spherical Shell (13) path.
The Specimen Injector (10) is used to draw the cooled specimen from the Specimen Cooling Block (7).
The DCV (8) is operated to connect the Specimen Injector (10) and the Spherical Shell (13) paths, while blocking the Specimen Cooling Block (7) path.
The specimen is injected into the Spherical Shell (13) by using the Specimen Injector (10).
The Data Processor and Display (19) unit collects temperature vs time reading at the core and the surface of the Spherical Shell (13), calculates thermal conductivity of the test specimen with the calculation program, and displays the test specimen thermal conductivity value on the display.
The specimen is pulled from the Spherical Shell (13) back into the Specimen Injector (10).
The DCV (8) is operated to connect the Specimen Cooling Block (7) and the Specimen Injector (10) paths, while blocking the Spherical Shell (13) path.
The test specimen is pushed to the Specimen Cooling Block (7) using the Specimen Injector (10).
The Drain Valve (9) is operated to drain the test specimen out of the Specimen Cooling Block (7).

In at least an embodiment, the apparatus, of this invention, a processor is provided to record temperature at a core and surface. Temperatures at the core and surface of the thin spherical shell (13) are recorded, with respect to time, and are used in a mathematical model of transient state heat transfer between the thin spherical shell (13) and surrounding to find thermal conductivity of the specimen in the thin spherical shell (13).

The method uses transient state heat transfer model of a spherical body. To understand the modelling of this method, assume a body of spherical shape initially at uniform temperature T_i. At time t=0, the sphere is suddenly exposed to a surrounding at a temperature of T_8 and heat transfer coefficient h as shown in FIGURE 6.
FIGURE 6 illustrates a spherical body heat transfer with surrounding.

Temperature of the body as a function of time and radial distance from core of the sphere is given by the following equation (1)
?_r=(T(r,t)-T_8)/(T_i-T_8 )=A.exp?(-?^2 t).sin?(?r/R)/(?r/R)
Eq. (1)

Where,
A,? are functions of Biot number only
t = Fourier’s number.
t= time
r= radial distance of point where instantaneous temperature T(r, t) is being considered
R= radius of the sphere
?_r = dimensionless temperature at radius r and time t

Applying Eq. (1) at the core of the sphere (r = 0),
?_o=(T(0,t)-T_8)/(T_i-T_8 )=A.exp?(-?^2 t) (lim-(r?0)??sin?(?r/R)/(?r/R)? )=A.exp?(-?^2 t)
Taking ratio of dimensionless temperature at any radius r to that at core, we get
?_r/?_o =sin?(?r/R)/(?r/R)
At the surface of the sphere, r=R, above formula reduces to equation (2),
?_R/?_o =sin?(?)/?
Eq. (2)

It shows that if temperature at the core and at the surface of the sphere is measured, ? can be calculated.
? is a function of Biot number only, as given in Eq.(3)
(1-? cot???)=Bi? Eq. (3)

From equation (3), if ? is known, Biot number can be obtained.
Bi=hL /k ?k=hL/Bi
Eq. (4)

L= characteristic length which is equal to radius of the sphere R
k= thermal conductivity of the material of sphere
From equation (4), with known values of h, L and Bi, Thermal Conductivity of the spherical body can be calculated.
If the spherical body is of a liquid, contained in a thin spherical shell, the above mathematical model can be applied with following assumptions
The spherical shell containing the liquid has negligible thermal resistance, which can be a valid assumption if the shell is made of high thermal conductivity material (e.g. Cu) and thickness is small enough to have negligible temperature drop across it.
Natural convection inside the spherical mass of liquid is negligible, which can be a plausible assumption if the sphere diameter is designed to be slightly above the diameter required to overcome lumped capacity.

As the temperature of the sphere during heat transfer is non-uniform, the calculated thermal conductivity can be considered to be at average of the core and surface temperature of the sphere.
The average of the core and surface temperature of the sphere changes with time, thus the calculated thermal conductivity also changes, which gives thermal conductivity values for the liquid at various temperatures.

In accordance with a non-limiting exemplary embodiment, an apparatus, of this invention was commissioned and tests were carried out on the set up. Results obtained, for thermal conductivity of the specimen, were in very good agreement with literature values. Being a transient-state-based apparatus, experimentation times were about 15 to 20 minutes which are much less than the experimentation times required in most of the prior art apparatus for liquid thermal conductivity measurement. It was also observed that the apparatus, of this invention, only requires temperature measurement for determining thermal conductivity of the specimen and data processing is also fairly simple. This eliminates the need of higher level of sophistication as demanded by prior art transient-state-based apparatus; thereby, giving economic advantage over prior art apparatus.

Also, as only temperature, and no other parameters like heat flow, determines thermal conductivity measurement, the apparatus, of this invention, is less prone to measurement errors. The apparatus has a unique feature that it can measure thermal conductivity variation with temperature in a single experiment; this makes the apparatus time efficient when it comes to measuring thermal conductivity of specimen at various temperatures.

It was observed that:
the apparatus, of this invention, works in transient state, and therefore allows faster experimentation than prior art (steady state) apparatus;
the apparatus, of this invention, is especially suitable for volatile liquids while prior art methods tend to give erroneous results with volatile test specimen
the apparatus, of this invention, allows measurement of thermal conductivity at various temperatures (i.e. k variation with T), in a single experiment, which is not possible with prior art apparatus;
the apparatus, of this invention, is economical.

According to a first non-limiting exemplary embodiment, Test was conducted with water as specimen. Average ambient temperature around the sphere was recorded. Temperature of the cooled liquid at the sphere center (T0) and at inner surface of sphere (TR) was recorded.
Table 1, below, shows readings and Table 2 shows the corresponding test results:

Ambient Temperature (Tambient), °C 31.38

TEST DATA
T0 (°C) TR (°C) ?0 = Tambient - T0 (°C) ?R = Tambient - TR (°C) ?R/?0
19.50 20.38 11.88 11.005 0.926347
20.00 21.38 11.38 10.005 0.879174
19.75 21.88 11.63 9.505 0.817283
20.00 21.88 11.38 9.505 0.835237
19.75 21.88 11.63 9.505 0.817283
20.00 21.63 11.38 9.755 0.857206
19.75 22.13 11.63 9.255 0.795787
19.75 21.63 11.63 9.755 0.838779
20.00 21.88 11.38 9.505 0.835237
19.75 21.88 11.63 9.505 0.817283
19.75 21.13 11.63 10.255 0.881771
20.25 21.63 11.13 9.755 0.876460
19.50 21.13 11.88 10.255 0.863215
20.00 21.38 11.38 10.005 0.879174
20.25 21.13 11.13 10.255 0.921384
20.25 21.63 11.13 9.755 0.876460
20.00 21.88 11.38 9.505 0.835237
20.25 21.63 11.13 9.755 0.876460
20.00 21.38 11.38 10.005 0.879174
20.25 21.63 11.13 9.755 0.876460
20.25 21.38 11.13 10.005 0.898922
20.00 21.38 11.38 10.005 0.879174
20.50 21.38 10.88 10.005 0.919577
19.75 21.13 11.63 10.255 0.881771
20.25 21.38 11.13 10.005 0.898922
20.50 21.38 10.88 10.005 0.919577
20.50 21.38 10.88 10.005 0.919577
20.00 21.63 11.38 9.755 0.857206
20.50 21.13 10.88 10.255 0.942555
20.25 21.38 11.13 10.005 0.898922
20.25 21.38 11.13 10.005 0.898922
19.75 21.38 11.63 10.005 0.860275
20.00 21.13 11.38 10.255 0.901142
20.25 21.38 11.13 10.005 0.898922
20.25 21.63 11.13 9.755 0.876460
20.50 21.38 10.88 10.005 0.919577
20.25 21.38 11.13 10.005 0.898922
20.50 21.13 10.88 10.255 0.942555
20.50 21.13 10.88 10.255 0.942555
20.25 21.38 11.13 10.005 0.898922
20.50 21.13 10.88 10.255 0.942555
20.50 21.63 10.88 9.755 0.896599
20.75 20.88 10.63 10.505 0.988241
20.00 21.13 11.38 10.255 0.901142
20.50 21.63 10.88 9.755 0.896599
20.75 21.13 10.63 10.255 0.964722
20.50 21.63 10.88 9.755 0.896599
20.50 21.63 10.88 9.755 0.896599
20.25 21.13 11.13 10.255 0.921384
20.75 21.13 10.63 10.255 0.964722
20.50 21.13 10.88 10.255 0.942555
20.75 21.38 10.63 10.005 0.941204
20.50 21.13 10.88 10.255 0.942555
20.25 21.38 11.13 10.005 0.898922
20.00 21.13 11.38 10.255 0.901142
20.25 21.38 11.13 10.005 0.898922
20.75 21.13 10.63 10.255 0.964722
20.00 20.88 11.38 10.505 0.923111
20.75 21.38 10.63 10.005 0.941204
19.75 21.38 11.63 10.005 0.860275
20.75 21.88 10.63 9.505 0.894167
20.50 21.13 10.88 10.255 0.942555
20.50 21.63 10.88 9.755 0.896599
20.75 21.63 10.63 9.755 0.917686
20.50 21.38 10.88 10.005 0.919577
20.75 21.63 10.63 9.755 0.917686
20.75 21.63 10.63 9.755 0.917686
20.25 21.38 11.13 10.005 0.898922
20.75 21.63 10.63 9.755 0.917686
20.75 21.63 10.63 9.755 0.917686
20.50 21.38 10.88 10.005 0.919577
20.50 21.38 10.88 10.005 0.919577
20.75 21.38 10.63 10.005 0.941204
20.75 21.63 10.63 9.755 0.917686
21.00 21.63 10.38 9.755 0.939788
21.00 21.63 10.38 9.755 0.939788
20.50 21.38 10.88 10.005 0.919577
20.75 21.88 10.63 9.505 0.894167
21.00 21.38 10.38 10.005 0.963873
21.00 21.38 10.38 10.005 0.963873
21.00 21.13 10.38 10.255 0.987958
21.00 21.88 10.38 9.505 0.915703
21.00 21.38 10.38 10.005 0.963873
20.75 21.38 10.63 10.005 0.941204
21.00 21.63 10.38 9.755 0.939788
21.00 21.63 10.38 9.755 0.939788
20.75 21.63 10.63 9.755 0.917686
21.00 22.13 10.38 9.255 0.891618
21.00 21.38 10.38 10.005 0.963873
21.00 21.63 10.38 9.755 0.939788
20.50 21.88 10.88 9.505 0.873621
21.25 21.88 10.13 9.505 0.938302
21.25 21.63 10.13 9.755 0.962981
21.00 21.38 10.38 10.005 0.963873
20.75 21.38 10.63 10.005 0.941204
21.00 21.38 10.38 10.005 0.963873
20.75 21.88 10.63 9.505 0.894167
21.00 21.38 10.38 10.005 0.963873
20.75 21.63 10.63 9.755 0.917686
20.75 21.88 10.63 9.505 0.894167
21.25 21.63 10.13 9.755 0.962981
20.75 21.88 10.63 9.505 0.894167
21.00 21.63 10.38 9.755 0.939788
21.25 21.88 10.13 9.505 0.938302
21.25 21.38 10.13 10.005 0.987660
21.25 21.38 10.13 10.005 0.987660
20.75 21.63 10.63 9.755 0.917686
20.50 21.63 10.88 9.755 0.896599
20.75 21.38 10.63 10.005 0.941204
21.25 21.38 10.13 10.005 0.987660
21.00 21.88 10.38 9.505 0.915703
20.75 21.88 10.63 9.505 0.894167
21.00 21.38 10.38 10.005 0.963873
21.00 21.63 10.38 9.755 0.939788
21.25 21.88 10.13 9.505 0.938302
21.25 21.63 10.13 9.755 0.962981
20.75 22.13 10.63 9.255 0.870649
21.25 21.63 10.13 9.755 0.962981
21.25 21.88 10.13 9.505 0.938302
21.25 21.63 10.13 9.755 0.962981
21.50 21.88 9.88 9.505 0.962045
21.00 21.88 10.38 9.505 0.915703
20.75 21.63 10.63 9.755 0.917686
21.25 22.13 10.13 9.255 0.913623
21.25 22.13 10.13 9.255 0.913623
20.75 22.13 10.63 9.255 0.870649
21.25 21.63 10.13 9.755 0.962981
20.75 21.63 10.63 9.755 0.917686
20.50 22.13 10.88 9.255 0.850643
21.25 21.38 10.13 10.005 0.987660
21.25 21.88 10.13 9.505 0.938302
21.25 21.88 10.13 9.505 0.938302
21.25 22.13 10.13 9.255 0.913623
21.25 22.13 10.13 9.255 0.913623
21.00 21.63 10.38 9.755 0.939788
21.25 21.88 10.13 9.505 0.938302
21.50 22.13 9.88 9.255 0.936741
21.25 21.88 10.13 9.505 0.938302
21.50 21.88 9.88 9.505 0.962045
21.25 22.13 10.13 9.255 0.913623
21.25 22.13 10.13 9.255 0.913623
21.00 22.13 10.38 9.255 0.891618
21.00 21.63 10.38 9.755 0.939788
21.00 22.13 10.38 9.255 0.891618
21.50 21.88 9.88 9.505 0.962045
21.25 21.88 10.13 9.505 0.938302
21.25 21.88 10.13 9.505 0.938302
21.00 21.63 10.38 9.755 0.939788
TABLE 1
TEST RESULT
Average ?R/?0 0.916632
? (solving equation ?R/?0 = sin(?)/?) 0.71639
Bi (from equation Bi = 1 - ?.cot(?) ) 0.177226209
Surrounding heat transfer coefficent (h), W/m2.°C 5.9789
Sphere radius (L), meter 0.018
k (experimental) (from equation k = h.L/Bi) 0.607247656
k (theoretical) 0.6
error % 1.2079427
TABLE 2

According to a first non-limiting exemplary embodiment, Test was conducted with water as specimen. Average ambient temperature around the sphere was recorded. Temperature of the cooled liquid at the sphere center (T0) and at inner surface of sphere (TR) was recorded.
Table 3, below, shows readings and Table 4 shows the corresponding test results:
Ambient Temperature (Tambient), °C 33.5

TEST DATA
T0 (°C) TR (°C) ?0 = Tambient - T0 (°C) ?R = Tambient - TR (°C) ?R/?0
20.75 20.88 12.75 12.625 0.990196
20.50 20.88 13 12.625 0.971154
20.75 21.38 12.75 12.125 0.950980
20.00 20.88 13.5 12.625 0.935185
20.25 21.13 13.25 12.375 0.933962
20.50 21.88 13 11.625 0.894231
20.50 21.63 13 11.875 0.913462
20.75 21.63 12.75 11.875 0.931373
20.50 21.38 13 12.125 0.932692
20.75 21.88 12.75 11.625 0.911765
20.75 21.63 12.75 11.875 0.931373
20.75 21.63 12.75 11.875 0.931373
20.50 21.63 13 11.875 0.913462
21.00 21.88 12.5 11.625 0.930000
20.50 21.88 13 11.625 0.894231
20.25 21.88 13.25 11.625 0.877358
21.00 22.13 12.5 11.375 0.910000
21.00 21.88 12.5 11.625 0.930000
19.75 21.88 13.75 11.625 0.845455
20.75 21.88 12.75 11.625 0.911765
20.75 22.13 12.75 11.375 0.892157
20.75 21.88 12.75 11.625 0.911765
20.75 22.13 12.75 11.375 0.892157
21.00 21.63 12.5 11.875 0.950000
20.75 22.13 12.75 11.375 0.892157
20.50 22.13 13 11.375 0.875000
20.50 21.88 13 11.625 0.894231
20.75 21.88 12.75 11.625 0.911765
20.75 21.88 12.75 11.625 0.911765
20.50 21.88 13 11.625 0.894231
20.50 22.13 13 11.375 0.875000
20.75 22.13 12.75 11.375 0.892157
20.75 22.13 12.75 11.375 0.892157
21.00 21.88 12.5 11.625 0.930000
21.00 22.13 12.5 11.375 0.910000
21.25 22.13 12.25 11.375 0.928571
21.00 21.63 12.5 11.875 0.950000
21.00 22.13 12.5 11.375 0.910000
20.75 21.88 12.75 11.625 0.911765
20.50 22.38 13 11.125 0.855769
20.75 22.13 12.75 11.375 0.892157
21.25 22.38 12.25 11.125 0.908163
21.25 22.38 12.25 11.125 0.908163
21.25 22.63 12.25 10.875 0.887755
21.00 22.38 12.5 11.125 0.890000
21.25 22.13 12.25 11.375 0.928571
21.00 22.38 12.5 11.125 0.890000
21.25 22.38 12.25 11.125 0.908163
21.00 21.88 12.5 11.625 0.930000
21.25 22.13 12.25 11.375 0.928571
21.00 22.13 12.5 11.375 0.910000
21.50 22.13 12 11.375 0.947917
21.25 22.13 12.25 11.375 0.928571
21.00 22.38 12.5 11.125 0.890000
21.25 22.38 12.25 11.125 0.908163
21.25 22.38 12.25 11.125 0.908163
21.25 22.38 12.25 11.125 0.908163
21.75 22.63 11.75 10.875 0.925532
21.75 22.63 11.75 10.875 0.925532
21.50 22.13 12 11.375 0.947917
21.50 22.63 12 10.875 0.906250
21.50 22.88 12 10.625 0.885417
21.25 22.88 12.25 10.625 0.867347
21.00 22.38 12.5 11.125 0.890000
21.00 22.38 12.5 11.125 0.890000
21.50 22.38 12 11.125 0.927083
21.50 22.88 12 10.625 0.885417
21.50 22.63 12 10.875 0.906250
21.75 22.88 11.75 10.625 0.904255
21.75 22.63 11.75 10.875 0.925532
21.25 22.88 12.25 10.625 0.867347
21.50 22.88 12 10.625 0.885417
21.50 22.88 12 10.625 0.885417
21.50 22.88 12 10.625 0.885417
21.75 22.63 11.75 10.875 0.925532
21.00 22.63 12.5 10.875 0.870000
21.50 23.13 12 10.375 0.864583
21.50 22.88 12 10.625 0.885417
21.25 22.63 12.25 10.875 0.887755
21.25 23.13 12.25 10.375 0.846939
22.50 23.38 11 10.125 0.920455
22.25 23.13 11.25 10.375 0.922222
21.50 22.63 12 10.875 0.906250
21.50 23.13 12 10.375 0.864583
22.00 23.13 11.5 10.375 0.902174
21.75 23.13 11.75 10.375 0.882979
21.75 22.88 11.75 10.625 0.904255
21.50 22.88 12 10.625 0.885417
22.00 22.63 11.5 10.875 0.945652
21.50 22.88 12 10.625 0.885417
22.00 22.88 11.5 10.625 0.923913
22.00 22.88 11.5 10.625 0.923913
21.50 23.38 12 10.125 0.843750
21.50 22.88 12 10.625 0.885417
21.75 23.13 11.75 10.375 0.882979
22.00 22.88 11.5 10.625 0.923913
21.75 22.88 11.75 10.625 0.904255
22.00 22.88 11.5 10.625 0.923913
21.50 23.13 12 10.375 0.864583
22.25 23.13 11.25 10.375 0.922222
22.00 23.38 11.5 10.125 0.880435
22.00 22.63 11.5 10.875 0.945652
21.75 22.88 11.75 10.625 0.904255
21.75 23.13 11.75 10.375 0.882979
21.75 22.63 11.75 10.875 0.925532
21.75 23.13 11.75 10.375 0.882979
22.25 23.13 11.25 10.375 0.922222
22.25 22.88 11.25 10.625 0.944444
22.25 22.88 11.25 10.625 0.944444
21.75 22.88 11.75 10.625 0.904255
22.50 23.13 11 10.375 0.943182
22.25 22.88 11.25 10.625 0.944444
22.25 23.13 11.25 10.375 0.922222
22.00 23.13 11.5 10.375 0.902174
22.00 23.13 11.5 10.375 0.902174
21.75 22.63 11.75 10.875 0.925532
22.00 22.63 11.5 10.875 0.945652
22.25 22.88 11.25 10.625 0.944444
22.25 23.13 11.25 10.375 0.922222
21.75 23.13 11.75 10.375 0.882979
22.25 23.38 11.25 10.125 0.900000
22.25 23.13 11.25 10.375 0.922222
21.75 23.13 11.75 10.375 0.882979
21.75 23.13 11.75 10.375 0.882979
22.25 23.13 11.25 10.375 0.922222
22.25 23.38 11.25 10.125 0.900000
22.75 23.13 10.75 10.375 0.965116
22.50 22.63 11 10.875 0.988636
22.25 23.38 11.25 10.125 0.900000
22.50 23.13 11 10.375 0.943182
22.25 22.88 11.25 10.625 0.944444
22.25 23.38 11.25 10.125 0.900000
22.50 22.63 11 10.875 0.988636
22.50 23.63 11 9.875 0.897727
22.00 23.13 11.5 10.375 0.902174
22.50 23.13 11 10.375 0.943182
22.50 23.38 11 10.125 0.920455
22.50 23.38 11 10.125 0.920455
22.75 23.38 10.75 10.125 0.941860
22.75 23.13 10.75 10.375 0.965116
22.50 23.38 11 10.125 0.920455
22.75 23.13 10.75 10.375 0.965116
22.50 23.38 11 10.125 0.920455
22.75 23.38 10.75 10.125 0.941860
22.50 23.38 11 10.125 0.920455
22.25 23.13 11.25 10.375 0.922222
22.50 23.38 11 10.125 0.920455
22.00 23.63 11.5 9.875 0.858696
22.75 22.88 10.75 10.625 0.988372
22.75 23.88 10.75 9.625 0.895349
TABLE 3

TEST RESULT
Average ?R/?0 0.911726
? (solving equation ?R/?0 = sin(?)/?) 0.737743
Bi (from equation Bi = 1 - ?.cot(?) ) 0.188365203
Surrounding heat transfer coefficent (h), W/m2.°C 6.2536
Sphere radius (L), meter 0.018
k (experimental) (from equation k = h.L/Bi) 0.59758808
k (theoretical) 0.6
error % -0.401986666
TABLE 4

The TECHNICAL ADVANCEMENT of this invention lies in providing an apparatus which comprises a cooling block along with arrangement of spherical shell along with the placement of thermocouples in it is unique injection and removal of liquid from both the cooling arrangement and the spherical shell.

While this detailed description has disclosed certain specific embodiments for illustrative purposes, various modifications will be apparent to those skilled in the art which do not constitute departures from the spirit and scope of the invention as defined in the following claims, and it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation.

,CLAIMS:WE CLAIM,

1. An apparatus to determine thermal conductivity of volatile liquids, said apparatus comprising:
- a liquid cooling system consisting, essentially of,
o a specimen cooling block (7) configured to hold specimen liquid to be cooled with coolers (1); and
o a coupled water circulation block (3) in order to create a continuous flow of water for said system, said liquid cooling system configured to hold liquid to be cooled,
o a first temperature sensor (16) configured to measure temperature of said specimen in said specimen cooling block (7);
said liquid cooling system, along with said cooler (1), being provisioned in an inclined manner so as to natural convection of specimen liquid for faster cooling and to be able to drain the specimen by gravity;
- a spherical shell assembly (13) consisting, essentially of,
o a spherical shell (13) configured to receive said specimen from said a specimen cooling block (7);
o temperature sensors (17, 18) in order to measure temperature of said specimen, at a core of said assembly (13) and an inner surface of said assembly (13), in order to compute thermal conductivity of said test specimen;
o a capillary (14) connected to said spherical shell (13) in order to inject said specimen into said spherical shell (13) in order to give minimal contact to the spherical shell (13) area and in order to minimize heat transfer through said capillary (14);
- a data handling unit consisting, essentially of,
o data handling unit configured to receive temperature data from said first sensor (16) in order to determine when to stop cooling, said second sensor (17) in order to determine thermal conductivity of said specimen, said third sensor (18) in order to determine thermal conductivity of said specimen,

2. The apparatus as claimed in claim 1 wherein, said coolers (1) are Peltier coolers.

3. The apparatus as claimed in claim 1 wherein, said water circulation block (3) being mounted on a heat sink (4) to assist removal of heat in order to cool said liquid held in said cooling block (7).

4. The apparatus as claimed in claim 1 wherein, said liquid cooling system comprising a pump (5) configured to pump water in order to create a continuous flow of water through said water circulation Block (3).

5. The apparatus as claimed in claim 1 wherein, said cooling block (7) being a cuboidal shape made of high thermal conductivity material for faster heat removal from the liquid specimen and being insulated from the surrounding to minimize heat ingress to the test specimen.

6. The apparatus as claimed in claim 1 wherein, said cooling block (7) having various ports and outlets, in that, being provisioned:
- a port to inject / transfer said specimen into said cooling block (7);
- a port to insert a first temperature Sensor (16) in said cooling block (7) for said specimen cooling temperature measurement;
- an outlet connected to a direction control valve (DCV) (8) for injecting said specimen to said spherical shell (13); and
- an outlet connected to a drain valve (9) to drain said specimen out of said cooling block (7).

7. The apparatus as claimed in claim 1 wherein, said temperature sensors (17, 18) being a second temperature sensor (17) and a third temperature sensor (18).

8. The apparatus as claimed in claim 1 wherein, said apparatus comprising a tube being a Temperature Sensor Guide (15) in order to provide rigid support to said spherical shell assembly (13) and in order to enable insertion of said temperature sensors (17, 18) into said spherical shell (13).

9. The apparatus as claimed in claim 1 wherein, a direction control valve (DCV) (8) is configured between said specimen cooling block (7) and said spherical shell (13) in order to control the direction of transfer of the test specimen between said specimen cooling block (7) and said spherical shell (13), in that, said direction control valve (DCV) (8) being a 3-way direction control valve (DCV) such that:
- a first tube, connected to said 3-way direction control valve (DCV) (8), being used to connect to said specimen cooling block (7);
- a second tube, connected to said 3-way direction control valve (DCV) (8), being used to connect to a specimen injector (10); and
- a third tube, connected to said 3-way direction control valve (DCV) (8), being used to connect to said spherical shell (13).
such that said direction control valve (DCV) (8) being configured to connect any two paths at a time, while blocking a third path.

Dated this 22nd day of July, 2023

CHIRAG TANNA
of INK IDÉE
APPLICANT’S PATENT AGENT
REGN. NO. IN/PA - 1785