DESC:FIELD OF THE INVENTION
This invention relates to the field of refrigeration system for cooling of liquid container. More particularly, the present invention related to quick cooling of liquid container within few minutes.
BACKGROUND OF THE INVENTION
Global warming causes an increase in the temperature of the earth. Therefore summer is getting hotter and winters are getting less cold. Because of hotter summer, the demand for cool beverages and water, has increased. With the increase in demand for cool beverages and water, demand for refrigeration system has also increased. The compressor runs continuously and consumes huge energy. The conventional refrigeration system uses a fixed speed heat pump/compressor which runs constantly at a rated speed all the time dragging a certain amount of power continuously to cool beverages and water at particular temperature. Once attaining the set temperature the compressor trips and when it starts again it drags
a heavy amount of starting current resulting in jerk load. Some existing methods of refrigeration system have been developed from time to time to reduce energy. But the current refrigeration system is costly in operation for beverage vendor and also take long to cool down the beverages.
US10024586B2 discloses A compact rapid liquid chilling apparatus and method are provided. A liquid is placed in a container having an inherent void volume. The housing includes a container-securing space dimensioned to receive ice and maintain substantially all of the ice atop the container placed therein and in thermal communication with the container without allowing substantially any of the ice to fall below the container. A rotating mechanism disposed in the housing rotates the container placed in the container-securing space. As the ice melts as it chills the rotating container, the resulting water falls freely below the container as substantially all of the unmelted ice remains above the container. A lid preferably closes around the container to form a portion of the container-securing space when closed. The lid preferably includes an ice supply window, and an ice measuring bin preferably is attachable to the window..
The existing invention lack in the innovation as the existing inventions are not able to overcome the problem associated with energy consumption and are unable to reduce temperature of liquid quickly. Thus there is a need for the present invention to overcome the above mention problems.
OBJECTIVE OF THE INVENTION
The main objective of the present invention is to develop a fast cooling refrigeration system.
Another objective of the present invention is to develop an easy and cost-effective refrigeration system to quickly cool down the liquid container with low energy consumption.
Yet another objective of the present invention is to quickly cool down the liquid container with less energy.
Yet another objective of the present invention is to effectively help the user.
Yet another objective of the present invention is to provide a cleaner environment.
Yet another objective of the present invention is to provide a system that can cut down cost of operation of refrigeration system for beverage vendor by reducing energy consumption.
Further objectives, advantages, and features of the present invention will become apparent from the detailed description provided hereinbelow, in which various embodiments of the disclosed invention are illustrated by way of example
SUMMARY OF THE INVENTION
The present invention relates to a fast cooling system for quick cooling of a liquid container, the includes a fast cooling compartment, a refrigeration compartment, and a motor. The fast cooling compartment includes a rotary housing, a liquid container holder, a lid, and an evaporator coil. The rotary housing is a container a a that is surrounded by cooling medium which cools the liquid containers. The liquid container holder is placed inside the rotary housing. The liquid container holder holds the liquid container, where the rotation motion is transferred to the liquid container thus separating the cooling medium from the liquid container through a thin wall of the liquid container holder. The lid covers the top part of the rotary housing from where the liquid container is placed inside the rotary holder. The evaporator coil wrapped around the external surface of the rotary housing. The evaporator coil exchanges heat from the cooling medium and thus refrigerant inside the evaporator coil becomes superheated vapor refrigerant and the cooling medium gets cooled down. The evaporator coil includes a suction pipe, and a discharge pipe. The suction pipe, and the discharge pipe are connected to the evaporator coil of the rotary housing. The shaft of the motor is connected to the rotary housing through rotary shaft that is rotated by the motor to quickly cool down the liquid containers inside the rotary holder. Herein, the motor rotates the rotary housing clockwise and anti-clockwise, by doing so the cooling medium inside the rotary housing, gets stirred to cool the liquid container placed inside the rotary holder. The refrigeration compartment is attached to the fast cooling compartment. The refrigeration compartment includes a refrigeration unit. The refrigeration unit is used to cool down the cooling medium cool inside the rotary housing through the evaporator coil. The refrigeration unit includes a condenser, and a compressor. The condenser is connected to the discharge pipe of the evaporator coil. The compressor is connected to the suction pipe of the evaporator coil. The compressor compresses the superheated refrigerant coming from the evaporator coil and passes the suction pipe to the condenser. Herein, the condenser cools down and converts superheated vapor refrigerant to the saturated liquid refrigerant and then passed the saturated liquid refrigerant through an expansion valve to the evaporator coil to cool down the cooling medium. The present invention cools down the liquid container from 38 Degree Celsius to 1 Degree Celsius within 2 minutes with help of the cooling medium.
The main advantage of the present invention is that fast cooling refrigeration system develops a fast-cooling refrigeration system.
Another advantage of the present invention developed an easy and cost-effective refrigeration system that quickly cool down the liquid container with low energy consumption.
Yet another advantage of the present invention that present invention effectively help the user.
Yet another advantage of the present invention is that the present invention provides provide a system that can cut down cost of operation of refrigeration system for beverage vendor by reducing energy consumption.
Further objectives, advantages, and features of the present invention will become apparent from the detailed description provided herein below, in which various embodiments of the disclosed invention are illustrated by way of example.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings are incorporated in and constitute a part of this specification to provide a further understanding of the invention. The drawings illustrate one embodiment of the invention and together with the description, serve to explain the principles of the invention.
Fig1.illustrates a fast cooling system for quick cooling of a liquid container.
Fig2.illustrates an embodiment of fast cooling system for quick cooling of a liquid container.
DETAILED DESCRIPTION OF THE INVENTION
Definition
The terms “a” or “an”, as used herein, are defined as one or as more than one. The term “plurality”, as used herein, is defined as two as or more than two. The term “another”, as used herein, is defined as at least a second or more. The terms “including” and/or “having”, as used herein, are defined as comprising (i.e., open language). The term “coupled”, as used herein, is defined as connected, although not necessarily directly, and not necessarily mechanically.
The term “comprising” is not intended to limit inventions to only claiming the present invention with such comprising language. Any invention using the term comprising could be separated into one or more claims using “consisting” or “consisting of” claim language and is so intended. The term “comprising” is used interchangeably used by the terms “having” or “containing”.
Reference throughout this document to “one embodiment”, “certain embodiments”, “an embodiment”, “another embodiment”, and “yet another embodiment” or similar terms means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearances of such phrases or in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics are combined in any suitable manner in one or more embodiments without limitation.
The term “or” as used herein is to be interpreted as an inclusive or meaning any one or any combination. Therefore, “A, B or C” means any of the following: “A; B; C; A and B; A and C; B and C; A, B and C”. An exception to this definition will occur only when a combination of elements, functions, steps or acts are in some way inherently mutually exclusive.
As used herein, the term "one or more" generally refers to, but is not limited to, singular as well as the plural form of the term.
The drawings featured in the figures are to illustrate certain convenient embodiments of the present invention and are not to be considered as a limitation to that. The term "means" preceding a present participle of an operation indicates the desired function for which there is one or more embodiment, i.e., one or more methods, devices, or apparatuses for achieving the desired function and that one skilled in the art could select from these or their equivalent is given the disclosure herein and use of the term "means" is not intended to be limiting.
Fig.1 illustrates a fast cooling system(100) for quick cooling of a liquid container. The fast cooling system(100) includes a fast cooling compartment(118), a refrigeration compartment(106), and a motor(124). The fast cooling compartment(118) includes a rotary housing(102), a liquid container holder(120), a lid(122), and an evaporator coil(112). The rotary housing(102) is a container that contains a cooling medium that cools the liquid container. The liquid container holder(120) is placed inside the rotary housing(102) . The liquid container holder(120) holds the liquid container, thus separating the cooling medium from the liquid container through a thin wall of the liquid container holder(120). The lid(122) covers the top part of the rotary housing(102) from where the liquid container is placed inside the liquid container holder(120). The evaporator coil(112) wrapped around the external surface of the rotary housing(102). The evaporator coil(112) includes a suction pipe(114), and a discharge pipe(116). The suction pipe(114), and the discharge pipe(116) are connected to the evaporator coil(112) of the rotary housing(102). The shaft of the motor(124) is connected to the rotary housing(102) that is rotated by the motor(124) to quickly cool down the liquid container inside the liquid container holder(120). The refrigeration compartment(106) is attached to the fast cooling compartment(118). The refrigeration compartment(106) includes a refrigeration unit(104). The refrigeration unit(104) includes a condenser (108), and a compressor(110). The condenser(108) is connected to the discharge pipe(116) of the evaporator coil(112). The compressor(110) is connected to the suction pipe(114) of the evaporator coil(112).
Fig.2 illustrates an embodiment of fast cooling system(100) for quick cooling of a liquid container. The fast cooling system(100) includes a fast cooling compartment(118), a refrigeration compartment(106), and a motor(124). The fast cooling compartment(118) includes a rotary housing(102), a liquid container holder(120), a lid(122), and an evaporator coil(112). The rotary housing(102) is a container that contains a cooling medium that cools the liquid container. The liquid container holder(120) is placed inside the rotary housing(102). The liquid container holder(120) holds the liquid container, thus separating the cooling medium from the liquid container through a thin wall of the liquid container holder(120). The lid(122) covers the top part of the rotary housing(102) from where the liquid container is placed inside the liquid container holder(120). The evaporator coil(112) wrapped around the external surface of the rotary housing(102). The evaporator coil(112) includes a suction pipe(114), and a discharge pipe(116). The suction pipe(114), and the discharge pipe(116) are connected to the evaporator coil(112) of the rotary housing(102). The shaft of the motor(124) is connected to the rotary housing(102) that is rotated by the motor(124) to quickly cool down the liquid container inside the liquid container holder(120). The refrigeration compartment(106) is attached to the fast cooling compartment(118). The refrigeration compartment(106) includes a refrigeration unit(104). The refrigeration unit(104) includes a condenser (108), and a compressor(110). The condenser(108) is connected to the discharge pipe(116) of the evaporator coil(112). The compressor(110) is connected to the suction pipe(114) of the evaporator coil(112).
Fig. 5 illustrates an embodiment of a rotary housing(102). The rotary housing(102)includes a rotary holder(126), the liquid container holder(120), a rotary shaft(128). The liquid container holder(120) is placed inside the rotary holder(126). The shaft of the motor(124) is connected to rotary holder(126). The rotary holder(126), the rotary shaft(128), are surrounded by cooling medium which cools the liquid container
Fig. 6 illustrates an exploded view of an embodiment of a rotary housing(102). The rotary housing(102)includes a rotary holder(126), the liquid container holder(120), a rotary shaft(128), wheel(130). The liquid container holder(120) is placed inside the rotary holder(126). The shaft of the motor(124) is connected the rotary holder(126) through rotary shaft(128) that is rotated by the motor(124) to quickly cool down the liquid container inside the liquid container holder(120). The liquid container holder(120) holds the liquid container, and the liquid container holder(120) is placed inside the rotary holder(126) where the rotation motion is transferred to the liquid container. The rotary holder(126), the rotary shaft(128), and the least one wheel(130) are surrounded by the cooling medium which cools the liquid container.
The present invention relates to a fast cooling system for quick cooling of a liquid container, the includes a fast cooling compartment, a refrigeration compartment, and a motor. In an embodiment, herein, the fast cooling compartment, and the refrigeration compartment are filled with insulation material to protect the cooling medium from external heat. The fast cooling compartment includes a rotary housing, a liquid container holder, a lid, and an evaporator coil. The rotary housing is a container that contains a cooling medium that cools the liquid container. The rotary housing is including liquid container holder. The liquid container holder is placed inside the rotary housing. The lid covers the top part of the rotary housing from where the liquid container is placed inside the liquid container holder. The evaporator coil wrapped around the external surface of the rotary housing. The evaporator coil exchanges heat from the cooling medium and thus refrigerant inside the evaporator coil becomes superheated vapor refrigerant and the cooling medium gets cooled down. The evaporator coil includes a suction pipe, and a discharge pipe. The suction pipe, and the discharge pipe are connected to the evaporator coil of the rotary housing. In an embodiment, the evaporator coil has the following dimensions outer diameter: 7.94mm, thickness: 0.7mm, length: 9.2 m and is made of mild steel. The shaft of the motor is connected to the rotary housing . Herein, the motor rotates the liquid container holder clockwise and anti-clockwise, by doing so the cooling mediums inside the rotary housing, gets stirred to cool the liquid container placed inside the liquid container holder. In an embodiment, herein, the motor is rotated alternatively clockwise and anti-clockwise with 110 RPM. The refrigeration compartment is attached to the fast cooling compartment. The refrigeration compartment includes a refrigeration unit. The refrigeration unit is used to cool down the cooling medium to cool the rotary housing through the evaporator coil. The refrigeration unit includes a condenser, and a compressor. The condenser is connected to the discharge pipe of the evaporator coil. The compressor is connected to the suction pipe of the evaporator coil. The compressor compresses the superheated refrigerant coming from the evaporator coil and passes the suction pipe to the condenser. In an embodiment, the compressor is controlled with a PLC controller that switches on-off the compressor as per the requirement to save energy. In the preferred embodiment, the compressor in case of a mixture of water and glycol thereof as cooling medium has cooling capacity: 420W @ASHRAE 32LMBP and uses Refrigerant: R290 50gm. In an embodiment, the compressor(110) in case of water as cooling medium has cooling capacity: 552W @ASHRAE 32LMBP and uses Refrigerant: R290 65gm. In an embodiment, coils of the compressor have the following dimension outer diameter: 9.52 mm, thickness: 0.7mm, length: 6.4-7.4 m and is made of copper, and coils of the compressor has fins that are made of aluminum. Herein, the condenser cools down and converts superheated vapor refrigerant to the saturated liquid refrigerant and then passed the saturated liquid refrigerant through an expansion valve to the evaporator coil to cool down the cooling medium. In an embodiment, the cooling medium is including, but not limited to, a water, mixture of water and glycol thereof.

In an embodiment, the rotary housing includes a rotary holder, the liquid container holder, a rotary shaft, a wheel. The liquid container holder is placed inside the rotary holder. The shaft of the motor is connected to the rotary holder through rotary shaft that is rotated by the motor to quickly cool down the liquid container inside the liquid container holder. The motor rotates the rotary holder in clockwise and anti-clockwise, by doing so the cooling medium inside the rotary housing, gets stirred to cool the liquid container placed inside the liquid container holder. The liquid container holder holds the liquid container, the liquid container holder is placed inside the rotary holder where the rotation motion is transferred to the liquid container. The rotary holder, the rotary shaft, and the wheel are surrounded by cooling medium which cools the liquid container.
Characterized in that, the fast cooling system cools down the liquid container from 38 Degrees Celsius up to 1 Degree Celsius within a range of 2 to 5 minutes with the help of the cooling medium. In the preferred embodiment, the cooling medium is a mixture of Propylene glycol and water thus lowering the freezing point temperature of the cooling medium that helps in the fast cooling of the liquid container from 38 degrees Celsius to 1 Degree Celsius within 2 minutes. In the preferred embodiment, herein, adding 35% glycol by volume in water reduces the cooling medium freezing point to -16°C and helps in cooling the liquid container within 2 minutes.
In an embodiment, herein, the cooling medium as water is cooled down to 0°C helps in cooling the liquid container from 38 Degree Celsius to below 10 Degree Celsius within 5 minutes. In an embodiment, herein, the cooling medium as a mixture of glycol and water is cooled down to -12°C helps in cooling the liquid container from 38 Degree Celsius to 1 Degree Celsius within 2 minutes

In an embodiment, the present invention relates to a fast cooling system for quick cooling of a liquid container, the includes a fast cooling compartment, a refrigeration compartment, and a motor. In an embodiment, herein, the fast cooling compartment, and the refrigeration compartment are filled with insulation material to protect the cooling medium from external heat. The fast cooling compartment includes a rotary housing, a liquid container holder, a lid, and an evaporator coil. The rotary housing is a container that contains a cooling medium that cools the liquid container. The rotary housing includes liquid container holder. The liquid container holder is placed inside the rotary housing. The lid covers the top part of the rotary housing from where the liquid container is placed inside the liquid container holder. The evaporator coil wrapped around the external surface of the rotary housing. The evaporator coil exchanges heat from the cooling medium and thus refrigerant inside the evaporator coil becomes superheated vapor refrigerant and the cooling medium gets cooled down. The evaporator coil includes a suction pipe, and a discharge pipe. The suction pipe, and the discharge pipe are connected to the evaporator coil of the rotary housing. In an embodiment, the evaporator coil has the following dimensions outer diameter: 7.94mm, thickness: 0.7mm, length: 9.2 m and is made of mild steel. The shaft of the motor is connected to the rotary housing. Herein, the motor rotates the liquid container clockwise and anti-clockwise, by doing so the cooling medium inside the rotary housing, gets stirred to cool the liquid container placed inside the liquid container holder. In an embodiment, herein, the motor is rotated alternatively clockwise and anti-clockwise with RPM. The refrigeration compartment is attached to the fast cooling compartment. The refrigeration compartment includes a refrigeration unit. The refrigeration unit is used to cool down the cooling medium cool inside the rotary housing through the evaporator coil. The refrigeration unit includes one or more condensers, and one or more compressors. The one or more condensers are connected to the discharge pipe of the evaporator coil. The one or more compressors are connected to the suction pipe of the evaporator coil. The compressor compresses the superheated refrigerant coming from the evaporator coil and passes the suction pipe to one or more condensers. In an embodiment, the one or more compressors are controlled with a PLC controller that switches on-off the one or more compressors as per the requirement to save energy. In the preferred embodiment, the one or more compressors in case of a mixture of water and glycol thereof as cooling medium has cooling capacity: 420W @ASHRAE 32LMBP and uses Refrigerant: R290 50gm. In an embodiment, the one or more compressors in case of water as cooling medium has cooling capacity: 552W @ASHRAE 32LMBP and uses Refrigerant: R290 65gm. In an embodiment, coils of the one or more compressors have the following dimension outer diameter: 9.52 mm, thickness: 0.7mm, length: 6.4-7.4 m and is made of copper and coils of the one or more compressors have fins that are made of aluminum. Herein, one or more condensers cool down and convert superheated vapor refrigerant to the saturated liquid refrigerant and then passed the saturated liquid refrigerant through an expansion valve to the evaporator coil to cool down the cooling medium. In an embodiment, the cooling medium is including, but not limited to, a water, mixture of water and glycol thereof.

In an embodiment, the rotary housing includes a rotary holder, the liquid container holder, a rotary shaft, one or more wheel. The liquid container holder is placed inside the rotary holder. The shaft of the motor is connected to rotary holder through rotary shaft that is rotated by the motor to quickly cool down the liquid container inside the liquid container holder. The motor rotates rotary holder in clockwise and anti-clockwise, by doing so the cooling medium inside the rotary housing, gets stirred to cool the liquid container placed inside the liquid container holder. The liquid container holder holds the liquid container, the liquid container holder is placed inside the rotary holder where the rotation motion is transferred to the liquid container. The rotary holder, the rotary shaft, and the one or more wheel are surrounded by cooling medium which cools the liquid container.
Characterized in that, the fast cooling system(100) cools down the liquid container from 38 Degree Celsius up to 1 Degree Celsius within range of 2 to 5 minutes with help of the cooling medium. In the preferred embodiment, The cooling medium is a mixture of Propylene glycol and water thus lowering the freezing point temperature of the cooling medium that helps in the fast cooling of the liquid container from 38 degrees Celsius to 1 Degree Celsius within 2 minutes. In the preferred embodiment, herein, adding 35% glycol by volume in water reduces the cooling medium freezing point to -16°C and helps in cooling the liquid container within 2 minutes.
In the preferred embodiment, herein, the cooling medium as water is cooled down to 0°C helps in cooling the liquid container from 38 Degree Celsius to below 10 Degree Celsius within 5 minutes. In an embodiment, herein, the cooling medium as mixture of glycol and water is cooled down to -12°C helps in cooling the liquid container from 38 Degree Celsius to 1 Degree Celsius within 2 minutes
WORKING EXAMPLE:
Methodology of System Design for 38°C Ambient for Present Invention
The system is used to cool PET bottle within minutes. The initial temperature of liquid within the PET bottle is 38°C and our aim to cool it to below 10°C in the range of 5 to 2 minutes Vapor compression refrigeration system is used as cooling cycle. Below is method of selecting the various components of the present invention to get the desired results.
Compressor:
Compressor is the heart of any vapor compressor based refrigeration cycle. It provides the necessary flow to the refrigerants within the closed loop. For selecting a suitable compressor below is the mathematical modelling of simulation.
A PET bottle filled with liquid (either cold drink or water) is taken as main cooling object to cool below 10°C from 38°c in 5 minutes. Total heat load for fluid inside the PET bottle is calculated as below:
Q_liquid=m_liquid*?cp?_liquid*(T_a-T_b) (i)
Where:
Q_liquid is the heat load of liquid inside the bottle in jules
?cp?_liquid is the specific heat of liquid inside the bottle in J/kgK
T_a is the initial temperature of bottle in °C
T_b is the final temperature of bottle in °C
m_liquid is the mass of liquid inside the bottle in kg.
m_liquid=v_liquid*?_liquid (ii)
v_liquid is the volume of liquid inside the bottle in m^3
?_liquid is the density of liquid inside the bottle in kg/m^3
Heat load came from equation (i) is only liquid heat load.
Now heat load of bottle alone is calculated as per below equation
Q_b=m_b*?cp?_b*(T_a-T_b) (iii)
Where
Q_b is heat load of bottle material in Jules
?cp?_liquid is the specific heat of liquid inside the bottle in J/kgK
T_a is the initial temperature of bottle in °C
T_b is the final temperature of bottle in °C
m_liquid is the mass of liquid inside the bottle in kg
Cold tank is cylindrical in shape so heat leakage is calculated as per below equation.
Q_l=2*p*k*h*((T_a-T_b))/(Ln r_o/r_i ) (iv)
Where
Q_l is the heat leakage from outside to inside in W
k is thermal conductivity of insulating material W/mK
r_o is outer radius of tank in m
r_i is inner radius of tank in m
h is the height of tank in m
Equation (i) and (iii) is added and divide with time in s to calculate the heat transfer rate.
q=(?(Q?_liquid+Q_b))/t (v)
Equation (iv) and (v) is added to calculate the total required cooling capacity of compressor in W
Q_compressor= Q_l+q (vi)
Where
Q_compressor is the cooling capacity of compressor required
Condenser:
Condenser rejects the heat taken from the evaporator and also it rejects the heat required to raise the pressure from suction pressure to discharge pressure. To get the required cooling capacity at high ambient. Below is the step by step methodology we followed
Condenser heat rejection is calculated from pressure enthalpy chart of refrigerant used and the mass flow rate of required compressor.
Below is the cycle temperature where compressor need to balance to get the desired cooling capacity.
Evaporator temperature -25°C
Condenser temperature 54°C
Discharge temperature 95°C
Suction temperature 35°C

Q_C=m_ref*(h_d-h_l )*1000 (vii)
Where
Q_C is condenser heat rejection
m_ref is mass flow rate of refrigerant kg/s
h_d is the enthalpy of refrigerant at discharge temperature in kJ/kg
h_l is the enthalpy of refrigerant at condenser outlet in kJ/kg
m_ref is calculated as per below equation
m_ref=(n_eff*V_c*rps)/v_s (viii)
Where
n_eff is the volumetric efficiency
V_c is volume of cylinder of compressor in m^3
rps is the frequency of the compressor
v_s is the specific volume of refrigerant at suction temperature and pressure in ?m/kg?^3
From equation (vii), we calculated the condenser heat rejection. From this heat rejection we will calculate the area of condenser required.
Q_C=U_c*A_c*LMTD (ix)
Where
U_c is the overall heat transfer coefficient in W/mK
A_c is the area of condenser in m^2
LMTD is the logarithmic temperature difference in K
Overall heat transfer coefficient is calculated using the below formula
U_c= 1/(A_o/(h_i A_i )+(A_o*r_i*Ln(r_o/r_i ))/(A_i*k_w )+A_o/h_o ) (x)
Where
A_o is the outer area of condenser (tube area + fin area) in m^2
h_o and h_i are the outer and inner convective heat transfer coefficient in W/(m^2 K)
A_i is the inner area of the condenser tube
k_w is the thermal conductivity of the condenser tube material in W/mK
h_o (outer convective heat transfer coefficient is calculated as per below equation.
h_o=(k_a*D_h)/?Nu?_a (xi)
Where
k_a is the thermal conductivity of air in W/mK
D_h is the hydraulic diameter of condenser in m
?Nu?_a is the Nusselt number of air
Nusselt number can be calculated using the below equation
?Nu?_a=0.117*?Re?^0.65*?Pr?^(1/3) (xii)
Where
Re is Reynold number of air
Pr is prandtle number of air
Reynold number can be calculated using below equation
Re=(?_a*v*D_h)/µ_a (xiii)
Where
?_a is the density of air in kg/m^3
v is the face velocity of condenser
µ_a is the viscosity of air in kg/ms
Prandtle number is calculated using below equation
Pr=(µ_a*?Cp?_a)/k_a (xiv)
Where, ?Cp?_a is the specific heat of air in kj/kgK
With the help of equation (xi) we can calculate the outside convection heat transfer coefficient.
Internal Convective boiling heat transfer coefficient is calculated by using Shah’s correlation. According to Shah’s correlation, outside convective heat transfer coefficient is a product of convective heat transfer coefficient given by Dittus-Boelter equation.
h_i=h_l*[(1-x)^0.8+(3.8*x^0.76*(1-x)^0.04)/?Pr?^0.38 ] (xv)
Where, P_r=p/p_critical = Reduced pressure
h_l=(0.023*??Re?_f?^0.8*??pr?_f?^0.4*k_f)/D_i (xvi)
Where, ?Re?_f is the Reynold number of liquid refrigerant and ?Pr?_fis the Prandtl number of liquid refrigerant at condenser temperature.
Selection of Evaporator:
Evaporator is the main component that take out heat from the cooling area and thus reduced the temperature. In the present innovation skin evaporator is used which is wrapped around the inner wall of the cylinder. Below is the step by step process to select the length of the evaporator.
Cooling capacity of the system is calculated from pressure enthalpy chart of refrigerant used and the mass flow rate of required compressor.
Below is the cycle temperature where compressor need to balance to get the desired cooling capacity.
Evaporator temperature -25°C
Condenser temperature 54°C
Discharge temperature 95°C
Suction temperature 35°C
Q_e=m_ref*(h_ge-h_le )*1000 (xvii)
Where
Q_e is cooling capacity of compressor
m_ref is mass flow rate of refrigerant kg/s
h_ge is the enthalpy of vapor refrigerant at evaporator temperature in kJ/kg
h_le is the enthalpy of liquid refrigerant at evaporator temperature in kJ/kg
m_ref is calculated as per below equation
m_ref=(n_eff*V_c*rps)/v_s (xviii)
Where
n_eff is the volumetric efficiency
V_c is volume of cylinder of compressor in m^3
rps is the frequency of the compressor
v_s is the specific volume of refrigerant at suction temperature and pressure in ?m/kg?^3
From equation (vii), we calculated the condenser heat rejection. From this heat rejection we will calculate the area of condenser required.
Q_e=U_e*A_e*LMTD (xix)
Where
U_e is the overall heat transfer coefficient in W/mK
A_e is the area of condenser in m^2
LMTD is the logarithmic temperature difference in K
Overall heat transfer coefficient is calculated using the below formula
U_e= 1/(A_oe/(h_ie A_ie )+(A_oe*r_ie*Ln(r_oe/r_ie ))/(A_ie*k_t )+A_oe/h_oe ) (xx)
Where
A_oe is the outer area of evaporator (tube area + surface) in m^2
h_oe and h_ie are the outer and inner convective heat transfer coefficient in W/(m^2 K)
A_ie is the inner area of the evaporator tube
k_t is the thermal conductivity of the evaporator tube material in W/mK
Internal Convective boiling heat transfer coefficient is calculated by using Shah’s correlation. According to Shah’s correlation, outside convective heat transfer coefficient is a product of convective heat transfer coefficient given by Dittus-Boelter equation.
h_ei=h_li*[(1-x_i )^0.8+(3.8*?x_i?^0.76*(1-x_i )^0.04)/??Pr?_i?^0.38 ] (xxi)
Where,
?P_r?_i=p/p_critical = Reduced pressure for evaporator
h_li=(0.023*??Re?_fi?^0.8*??pr?_fi?^0.4*k_fi)/D_i (xxii)
Where, ?Re?_fi is the Reynold number of liquid refrigerant and ?Pr?_fiis the Prandtl number of liquid refrigerant at evaporator temperature.
Selection of Motor:
DC geared motor is used to generate the turbulence inside the bottle. Motor is used by calculating the torque requires. Our maximum bottle weight is 1 kg and the overall assembly weight is 3 kg.
Total torque require can be calculated using below equation:-
T_L=((µ*F_A*+m.g)*p*D)/2 (xxiii)
Where,
F_A is the viscous force or resistant force of cooling medium in N
m is the total mass to rotate kg
g is the gravitational constant m/s^2
µ is the friction coefficient (0.1~0.3)
D is the outer diameter of casing in m
Now to calculate the desired rpm, we need Reynold number. But we will get the desire result only when there is turbulent flow inside the liquid bottle that is being cooled using the mechanism.
For turbulent flow, Reynold number shall be more than 4000. So consider the value of Reynold number to 4000, we can calculate rpm as per below equation.
?Re?_l=(?_l*?_l*d)/µ_l (xxiv)
Where,
?Re?_l is Reynold number inside the liquid bottle
?_l is the density of liquid inside the bottle in kg/m^3
d is diameter of liquid bottle to be cooled in m
µ_l is the viscosity of liquid inside the bottle in pa.s
From equation (xxiv), we find the velocity of liquid inside the bottle. Using the diameter of bottle to be cooled we can find out the angular velocity as per below equation:
?_l=(?_l*2)/d (xxv)
Using the angular velocity (?_l), we can find out the required rotation of bottle to generate turbulent flow
rpm= ?_l*60 (xxvi)
Cooling medium:
Cooling medium is chosen such that temperature of final solution shall be less than 0°C, but water freeze at 0°C. to lower the temperature of water below 0°C some chemical need to be added but that chemical shall not harm the human body when come in direct contact. Propylene glycol is already available in the market and used in Eutectic freezers. Below is the effect on freezing point with respect to concentration of propylene glycol to water.
Now to select the temperature of propylene glycol and water, a theoretical simulation is carried out for various solution temperature (-15°C, -10°C and -5°C) and results are as mentioned in Fig.4 of Drawing. So from the theoretical simulation as shown in Fig.4, it is found that solution temperature should be -15°C. From Fig.3, it is observed that to obtain freezing temperature below -15°C, 35% glycol by volume to be added in water and which can reduce the solution freezing point to -16°C.
Using the above methodology below are the components specification:
Evaporator tube outer diameter: 7.94mm
Evaporator tube thickness: 0.7mm
Evaporator tube material: mild steel
Evaporator tube length: 9.2 m
Condenser tube outer diameter: 9.52mm
Condenser tube thickness; 0.7 mm
Condenser tube material: Copper
Condenser fin material: Aluminum
Condenser fin thickness: 0.1 mm
Condenser tube length: 7.4 m
Compressor cooling capacity: 420 W @ASHRAE 32LMBP
Refrigerant: R290 50 gm
Motor rpm: 110
Cooling medium solution: Water and propylene glycol
Cooling medium solution ratio: 35 propylene glycol: 65 Water
Cooling medium solution freezing point: -16°C
Cooling medium temperature: -12°C
Result and Discussion:
Using the instant cooling in the present innovation, we got temperature of PET bottle up to 1liter from 38°C to below 10°C within 5 minutes and can of 330ml is cooled from 38°C to below 10°C in 2 minute in case of water as cooling medium. Using the instant cooling in the present innovation, we got temperature of PET bottle up to 1liter from 38°C to 1°C within 2 minutes and can of 330ml is cooled from 38°C to 1°C in 1 minute in case of mixture of glycol and water as cooling medium. So, there is no need to keep storage of cold bottles in a separate refrigerator which consume space and much energy.
Further objectives, advantages, and features of the present invention will become apparent from the detailed description provided herein below, in which various embodiments of the disclosed present invention are illustrated by way of example and appropriate reference to accompanying drawings. Those skilled in the art to which the present invention pertains may make modifications resulting in other embodiment employing principles of the present invention without departing from its spirit or characteristics, particularly upon considering the foregoing teachings. Accordingly, the described embodiment are to be considered in all respects only as illustrative, and not restrictive, and the scope of the present invention is, therefore, indicated by the appended claims rather than by the foregoing description or drawings. Consequently, while the present invention has been described with reference to a particular embodiment, modifications of structure, sequence, materials, and the like apparent to those skilled in the art still fall within the scope of the invention as claimed by the applicant
,CLAIMS:I/WE CLAIM
1. A fast cooling system(100) for quick cooling of a liquid container, the system(100) comprising:
a fast cooling compartment(118), the fast cooling compartment(118) having
a rotary housing(102), the rotary housing(102) is a container that contains a cooling medium that cools the liquid container, the rotary housing(102) having
a liquid container holder(120), the liquid container holder(120) is placed inside the rotary housing(102), and the liquid container holder(120) holds the liquid container, and
a lid(122), the lid(122) covers the top part of the rotary housing(102) from where the liquid container is placed inside the liquid container holder(120), and
an evaporator coil(112), the evaporator coil(112) wrapped around the external surface of the rotary housing(102), the evaporator coil(112) exchanges heat from the cooling medium and thus refrigerant inside the evaporator coil(112) becomes superheated vapor refrigerant and the cooling medium gets cooled down, The evaporator coil(112) having
a suction pipe(114), and
a discharge pipe(116), the suction pipe(114), and the discharge pipe(116) are connected to the evaporator coil(112) of the rotary housing(102);
a motor(124), the shaft of the motor(124) is connected to the rotary housing(102) , wherein, the motor(124) rotates the liquid container holder(120) in clockwise and anti-clockwise, by doing so the cooling medium inside the rotary housing(102), gets stirred to cool the liquid container placed inside the liquid container holder(120);
a refrigeration compartment(106), the refrigeration compartment(106) is attached to the fast cooling compartment(118), the refrigeration compartment(106) having
a refrigeration unit(104), refrigeration unit(104) is used to cool down the cooling medium cool inside the rotary housing(102) through the evaporator coil(112), the refrigeration unit(104) having
an at least one condenser(108), at least one condenser (108) is connected to the discharge pipe(116) of the evaporator coil(112) through,
an at least one compressor(110), the at least one compressor(110) is connected to the suction pipe(114) of the evaporator coil(112) through, and the compressor(110) compresses the superheated refrigerant coming from the evaporator coil(112) and passes to the at least one condenser (108);
wherein, the at least one condenser(108) cools down and converts superheated vapor refrigerant to the saturated liquid refrigerant and then passed the saturated liquid refrigerant through an expansion valve to the evaporator coil(112) to cool down the cooling medium,
Characterized in that, the fast cooling system(100) cools down the liquid container from 38 Degree Celsius up to 1 Degree Celsius within range of 2 to 5 minutes with help of the cooling medium.
2.The rotary housing(102) as claimed in claim 1, the rotary housing(102) comprises:
a rotary holder(126);
the liquid container holder(120), the liquid container holder(120) is placed inside the rotary holder(126);
a rotary shaft(128), wherein, the shaft of the motor(124) is connected to the rotary holder(126) through rotary shaft(128) that is rotated by the motor(124) to quickly cool down the liquid container inside the liquid container holder(120), wherein, the motor(124) rotates the rotary housing(102) in clockwise and anti-clockwise, by doing so the cooling medium inside the rotary housing(102), gets stirred to cool the liquid container placed inside the liquid container holder(120);
an least one wheel(130);
wherein, the liquid container holder(120) holds the liquid container, the liquid container holder(120) is placed inside the rotary holder(126) where the rotation motion is transferred to the liquid container;
wherein, the rotary holder(126), the rotary shaft(128) and the least one wheel(130) are surrounded by cooling medium which cools the liquid container.
3. The system(100) as claimed in claim 1, wherein, the cooling medium is selected from a water, mixture of water and glycol thereof.
4. The system(100) as claimed in claim 1, wherein at least one compressor(110) in case of mixture of water and glycol thereof as cooling medium has cooling capacity: 420W @ASHRAE 32LMBP and uses Refrigerant: R290 50gm, wherein at least one compressor(110) in case of water as cooling medium has cooling capacity: 552W @ASHRAE 32LMBP and uses Refrigerant: R290 65gm.
5. The cooling medium as claimed in claim 1 and 3, wherein, adding 35% glycol by volume in water reduces the cooling medium freezing point to -16°C helps in cooling the liquid container within 5 minutes.
6. The cooling medium as claimed in claim 1 and 3, wherein, the cooling medium as water is cooled down to 0°C helps in cooling the liquid container from 38 Degree Celsius to below 10 Degree Celsius within 5 minutes, wherein, the cooling medium as mixture of glycol and water is cooled down to -12°C helps in cooling the liquid container from 38 Degree Celsius to 1 Degree Celsius within 2 minutes
7. The system(100) as claimed in claim 1, wherein, the fast cooling compartment(118), and the refrigeration compartment(106) are filled with insulation material to protect the cooling medium from external heat.
8. The system(100) as claimed in claim 1, wherein, the motor is rotated alternatively clockwise and anti-clockwise with 110 RPM.
9. The system(100) as claimed in claim 1, wherein, the evaporator coil(112) has the following dimensions outer diameter: 7.94mm, thickness: 0.7mm, length: 9.2 m and is made of mild steel.
10. The system(100) as claimed in claim 1, wherein, coils of the at least one compressor(110) has the following dimension outer diameter: 9.52 mm, thickness: 0.7mm, length: 6.4-7.4 m and is made of copper having and coils of the at least one compressor(110) have fins that are made of aluminum.