Description:TITLE OF THE INVENTION:
Solar operated bulk milk cooler module with thermal storage system

FIELD OF THE INVENTION:
The present invention relates to the field of bulk milk coolers which are used to store fresh milk at low temperature until it is ready for distribution, which is operated using electricity directly generated from solar energy and has a thermal storage system.

BACKGROUND OF THE INVENTION:
Cooling is a process in which heat is removed from one source and moved to another source. This process of cooling is performed in many places like household refrigerators, industrial freezers, cryogenics, air conditioners etc. Industrial freezers or coolers are usually big vessels which are used to cool various products. Cooling of these products in big vessels require the working of refrigeration systems with great capacities. Such refrigeration systems require large amount of electric power to operate. In absence of electricity, such cooling systems become inoperative, causing harm to stored products or perishable food items. Moreover the large amount of electricity used is mostly produced from non-renewable sources of energy, thus contributing to environmental pollution.
Milk and milk products are daily necessities throughout the world. Dairy industries collect milk from suppliers located at remote places in the country and dispense milk and milk products to the consumers. India being an agricultural country, the Indian dairy industry contributes a lot to the economy of the country. India occupies first position in the world milk production with 19% share in global milk output. Most of the milk in the country is produced by small, marginal farmers and landless labourers. Co-operative milk unions procure milk from these people for selling it as well as for manufacturing milk products and selling them. However the process of distributing and selling the procured milk or manufacturing milk products from it requires time. As per Codex Alimentarius, milk must be cooled preferably to 40C, immediately after milking. This is because milk gets spoiled within 3-4 hours of milking in hot environment due to the rapid multiplication of bacteria. So if fresh milk isn’t used within 2 hours of milking, it should be cooled to 40C or lower temperature. The quicker the milk is cooled after leaving an animal’s body, the better remains its quality. So the collected milk is stored in bulk milk cooling tanks.
Bulk milk tanks are large storage tanks for cooling and holding milk at a low temperature. These tanks increase the shelf life of milk, facilitates systematic and simple way of milk procurement, arrests bacterial growth, retains freshness and enhances the keeping quality of the milk, avoids economic losses to the producers due to spillage or curdling of milk, makes quality milk available for the production of quality products and ensures clean milk production and sale. Such tanks are one of the most important equipment of dairy farm. These tanks are generally made from stainless steel and used to store raw milk. Refrigeration systems are provided in such tanks to cool the milk to a very low temperature. These refrigeration systems consume a large amount of electricity to reduce the temperature of large quantities of milk. This electricity is obtained through grid supply. But milk is usually collected from remote locations where grid power may be either partially available or not available at the time of milk collection. So chilling of the milk is done by refrigeration systems operating with the help of diesel generators or transporting the milk to a nearby chilling centre which may result in the deterioration of the quality of milk. Moreover electricity is also required for functioning of the co-operative society administrative office, milk sample collection process, sample analyzer, pumps for transfer of milk from tanks to vehicles and operation of tube lights and fans. This electricity consumption is also added to the overall chilling cost for farmers. Conventional sources of electricity as well as diesel generators harm the environment as well as cause depletion of non-renewable sources of energy. So cooling systems utilizing renewable sources of energy, are being developed. Different kinds of such cooling units are available in the prior art.

US Patent 6469487 discloses a solar powered vapor compression refrigeration system which is made practicable with thermal storage and novel control techniques. In one embodiment, the refrigeration system includes a photovoltaic panel, a variable speed compressor, an insulated enclosure, and a thermal reservoir. The photovoltaic (PV) panel converts sunlight into DC (direct current) electrical power. The DC electrical power drives a compressor that circulates refrigerant through a vapor compression refrigeration loop to extract heat from the insulated enclosure. The thermal reservoir is situated inside the insulated enclosure and includes a phase change material. As heat is extracted from the insulated enclosure, the phase change material is frozen, and thereafter is able to act as a heat sink to maintain the temperature of the insulated enclosure in the absence of sunlight. The conversion of solar power into stored thermal energy is optimized by a compressor control method that effectively maximizes the compressor's usage of available energy. A capacitor is provided to smooth the power voltage and to provide additional current during compressor start-up. A controller monitors the rate of change of the smoothed power voltage to determine if the compressor is operating below or above the available power maximum, and adjusts the compressor speed accordingly. In this manner, the compressor operation is adjusted to convert substantially all available solar power into stored thermal energy.
US Patent 10280903 describes concentrated solar power systems using solar receivers, and related devices and methods in which low pressure solar receivers are provided that function to convert solar radiation energy to thermal energy of a working fluid, e.g., a working fluid of a power generation or thermal storage system. In some embodiments, low pressure solar receivers are provided herein that are useful in conjunction with gas turbine based power generation systems.
US Patent Application relates to a solar-powered freezer truck. Power for the refrigeration system may be provided by photovoltaic solar cells with battery storage. The refrigeration system may be adapted to run off the Direct Current System Voltage as an efficiency measure to avoid electrical conversion. The powered elements of the refrigeration system, the compressor, defroster, and condenser and evaporator fans may be configured to run on the System Voltage, which may be 24 volts Direct Current.
WO 2019222820 is directed to a motorized milking machine developed with a view to improving the manual, automatic and robotic milking machines currently on the market, said milking machine being characterized in that it comprises a milking machine and a cooler (condenser and evaporator) that are coupled to the actual system and which are driven by a power generator that runs on electrical or solar energy and/or a fuel of diesel-oil type, the generator in turn being driven by a motor, all these items of equipment being transported by vehicles, such as a truck, a pickup or a tractor, and taken to the grazing pasture in order for the milk to be collected and stored.
RU 2005123134 relates to a thermal regulator for milk which has cold source formed as reservoir containing cooling agent and connected through filter and pump with coiled cooling unit positioned within reservoir, electric regulation device, and control unit. Thermoelectric cooler provides additional cooling by feeding therefrom of cooled water into additional coiled heat-exchanger positioned within reservoir containing milk. Regulating device of thermal regulator allows various milk cooling patterns to be effectuated at different environmental temperatures.
JP 2011089722 provides a refrigerating/air conditioning system reducing CO2emission by using heat by a heat pump and a solar heat collector using natural energy. A regenerator 52 of an absorption type refrigerating machine 58 at least including an absorber 50, the regenerator 52, a condenser 54 and an evaporator 56 and a heat pump water heater 68 are interconnected via a hot water storage tank 70 and a hot water supply pipe 74. The solar heat collector 80 is connected to the hot water storage tank 70 via a heat exchanger 78, and hot water generated by the solar heat collector 80 and hot water generated by the heat pump water heater 68 are used for at least part of a drive heat source of the absorption type refrigerating machine 58.
KR 20170054395 discloses a medicinal storage container includes: a desiccant unit including external walls forming a gas-impermeable barrier around an interior desiccant region and including an aperture; a heating element; a controller operably attached to the heating element; a cooling unit; a compressor system including at least one evaporator coil unit, the compressor operably connected to the controller; a vapor conduit, the vapor conduit attached to a the desiccant unit at a first end, the vapor conduit attached to the evaporative cooling unit at a second end, the vapor conduit forming an internal, gas-impermeable passageway between the desiccant unit and the cooling unit; a vapor control unit attached to the vapor conduit and operably attached to the controller; and a medicinal storage unit including external walls encircling a medicinal storage region including a temperature sensor operably connected to the controller.
CN 106032918 discloses an intelligent solar air-conditioning system mainly comprises a heat collecting system, a refrigeration system, an energy storage system, a control system, an end air conditioning system, a circulation water pump and a circulation pipeline. The intelligent solar air-conditioning system is characterized in that the heat collecting system comprises a heat collecting device and an auxiliary heating device; a refrigeration unit in the refrigeration system is a refrigeration unit which can be driven by thermal energy, such as a lithium bromide refrigeration unit; the energy storage system comprises a hot water storage tank and a cold water storage tank; the control system is provided with a centralized control electric box therein, with heat collection and refrigeration being automatically and intelligently controlled by a microcomputer program; and the end air conditioning system comprises a fan coil. With high stability and high real-time performance, the intelligent solar air-conditioning system of the invention integrates the automatic control function, performs automatic intelligent control of heat collection and refrigeration by the microcomputer program according to the ambient temperature and the temperature of water from a heat collector, a cold water tank and a hot water tank, is able to run around the clock, and achieves the effects of energy saving and environmental protection.
CN 202842284 gives a raw milk collecting and treating equipment, and in particular relates to a raw milk quick-cooling device. The raw milk quick-cooling device comprises a milk collecting tank, a first heat exchanger and a thermal-insulation milk storage tank, wherein the milk collecting tank is used for storing the fresh squeezed raw milk; the thermal-insulation milk storage tank is used for storing the quickly-cooled milk liquid; the milk collecting tank is connected to a hot medium channel inlet of the first heat exchanger; a pump is arranged on the pipeline; the thermal-insulation milk storage tank is connected to a hot medium channel outlet of the first heat exchanger; the raw milk quick-cooling device further comprises a thermal-insulation water tank which is stored with low-temperature cooling water, wherein an inlet of the thermal-insulation water tank is connected to a cold medium channel outlet of the first heat exchanger by a pipeline; an outlet of the thermal-insulation water tank is connected to a cold medium channel inlet of the first heat exchanger by a pipeline; the cold medium channel inlet is provided with a pump for circulating the cooling water; the raw milk quick-cooling device further comprises a cooling system which keeps the cooling water in the thermal-insulation water tank at a low temperature, wherein the cooling system comprises a water cooler and a condenser,; the thermal-insulation water tank is connected with the water cooler by the pipeline; and the condenser is connected with the water cooler by the pipeline. The raw milk quick-cooling device has a reasonable structure and a good quick-cooling effect to the raw milk.
Indian Patent Application 2179/MUM/2011 relates to a solar powered bulk milk cooler storage system which is useful for storage facility for milk which are kept under cool temperature for preservation to retain its freshness and nutrient facts for 1 day.
Indian Patent Application 3268/MUM/2011 gives a cold storage with roof Integrated solar dryer and waste heat recovery which includes solar hot air panels integrated with the roof of the cold storage building and waste heat generated from the condenser of refrigeration system is also utilized for drying applications.
Indian Patent Application 3613/CHE/2013 describes a portable milk cooling system which includes a can and a refrigeration system. The can stores milk therein. The refrigeration system cools milk stored inside the can. The refrigeration system includes a compressor, a condenser, an expansion system and an evaporator coil. The compressor compresses a low pressure gaseous refrigerant to a high pressure gaseous refrigerant. The condenser facilitates condensation of high pressure gaseous refrigerant to a high pressure liquid refrigerant. The expansion system facilitates expansion of high pressure liquid refrigerant thereby reducing high pressure liquid refrigerant to a low pressure liquid refrigerant. The evaporator is functionally connected to the can and converts the low pressure liquid refrigerant into a low pressure gaseous refrigerant by absorbing heat from milk stored in the can, wherein the refrigeration system is powered by at least one of at least one solar photovoltaic cell and a single phase electric power.
Although a number of solar operated cooling units, refrigeration units, air-conditioning units etc are available in the prior art, a solar operated refrigeration system which generates and stores the thermal energy in thermal storage system with minimum loses and discharges this thermal energy to chill the fresh milk rapidly, when received, in the absence of sunlight and without the requirement of conventional electricity to chill and maintain the chilled milk at 40C, is the need of the day.

OBJECT OF THE INVENTION:
The main object of the invention is to provide a solar operated bulk milk cooler module with thermal storage system which uses solar power to generate thermal energy and operate a refrigeration system to chill the procured fresh milk to 40C and maintain the milk at that temperature until it is to be dispensed or used.
Another object of the invention is to provide a solar operated bulk milk cooler module with thermal storage system which stores the produced thermal energy in the thermal storage system and uses the stored thermal energy to chill the milk received during 1st milking cycle and 2nd milking cycle in the absence of solar energy.
Still another object of the invention is to provide a solar operated bulk milk cooler module with thermal storage system which facilitates immediate chilling of milk and maintaining it at the required temperature thereby preventing its deterioration.
Yet another object of the invention is to provide a solar operated bulk milk cooler module with thermal storage system which can function in absence of electricity without the requirement of fossil fuel for the cooling process.
A still another object of the invention is to provide a solar operated bulk milk cooler module with thermal storage system which stores thermal energy sufficient to chill milk procured from two milking cycles and maintain it at the chilled temperature.
A yet another object of the invention is to provide a solar operated bulk milk cooler module with thermal storage system which uses renewable source of energy (solar energy) for its operation and thus supports the use of clean energy.
A further object of the invention is to provide a solar operated bulk milk cooler module with thermal storage system which uses solar operated refrigerant pump to chill the milk wherein all the ancillary equipment at the milk collection unit operate using solar power thereby reducing the dependency on grid power.
A still further object of the invention is to provide a solar operated bulk milk cooler module with thermal storage system which is economical.

SUMMARY OF THE INVENTION:
The present invention relates to a solar operated bulk milk cooler module with thermal storage system which utilizes solar power to generate D.C. power to operate the refrigeration system and generate and store thermal energy by changing the phase of the refrigerant from liquid to solid. When fresh milk is received in this bulk milk cooler, the stored thermal energy is discharged in the cooler using a solar power operated refrigerant pump which chills the milk rapidly below 40C within the time range specified by ISO 5708 and BIS 3661. The chilled milk is stored at the said temperature until it is to be dispensed or used. During the storage if the temperature of the stored milk rises above 50C due to heat loss, the controller of the system automatically starts the working of the refrigerant pump until the milk is chilled back to 40C. The thermal storage system can store thermal energy sufficient to chill milk obtained in two milking cycles namely evening and morning, both of which are performed in the absence of sunlight. All the equipment of the system are solar operated and hence can function at locations and at occasions when conventionally used electricity is not available.

BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 gives the layout drawing of the solar operated bulk milk cooler module with thermal storage system
Fig. 2 gives the three dimensional view of the solar operated bulk milk cooler module with thermal storage system.
Fig. 3 gives the piping and instrumentation diagram of the solar operated bulk milk cooler module with thermal storage system.
Fig. 4 gives the table displaying the charging cycle of the thermal storage system.
Fig. 5 gives the table displaying the milk chilling time in the first milking cycle.
Fig. 6 gives the table displaying the milk chilling time in the second milking cycle.
Fig. 7 gives the table displaying the electrical load and operational charges of a conventional bulk milk cooler of 1 KL capacity running on grid electricity.
Fig. 8 gives the table displaying the electrical load and operational charges of a conventional bulk milk cooler of 1 KL capacity running on D.G. set.

DETAILED DESCRIPTION:
The nature of the invention and the manner in which it is performed is clearly described in the complete specification. The invention has various components and they are clearly described in the detailed description.
Bulk milk cooler systems are systems in which raw milk is stored until its dispensing or usage. As raw milk deteriorates very fast at ambient temperature, it needs to be cooled and stored at lower temperature until dispensing. Usually bulk milk coolers comprise of large tanks to store huge quantities of collected milk at low temperature. Fast cooling of this milk is essential to prevent its deterioration. This fast cooling of milk is done using refrigeration systems. These refrigeration systems comprise of compressors, condensers, controllers etc. and utilize a large amount of electricity to run the components and chill the milk rapidly.
During the cooling process, the compression of the refrigerant as well as its condensation is done using electricity. In the cooling process, the refrigerant initially arrives in the compressor at a low temperature as a low-pressure gas. The compressor squeezes the refrigerant fluid due to which the molecules of the fluid come close together. The closer these molecules get, the higher becomes their energy and temperature. This refrigerant leaves the compressor and enters the condenser at a high temperature and high pressure in gaseous state, which when leaves the condenser, is a condensed liquid under high pressure. This process of condensation uses a lot of energy. The refrigerant is then passed through an expansion device to an evaporator, i.e. the bulk milk cooler, where heat transfer takes place causing the chilling of the milk and vaporization of the refrigerant.
These conventional refrigeration systems are in-operable in the absence of electricity or grid power supply, due to which rapid milk deterioration of milk takes place. In the absence of electricity, diesel operated generator systems are used to run the refrigeration systems for chilling milk which lead to higher operational costs, environmental pollution as well as depletion of non-renewable resources.
The present invention relates to a solar operated bulk milk cooler module with thermal storage system which utilizes solar energy for the operation of all the components of the bulk milk cooler module and consists of a thermal storage system which stores the energy to be used for chilling the milk procured after each milking cycle, when solar energy is not available.
This solar operated bulk milk cooler module utilizes solar energy which is a renewable source of energy, for its working. Solar panels are present on top of the whole unit, which generate D.C. power with the help of solar radiation. This generated D.C power is used to run a specially designed refrigeration system, which utilizes solar power to generate thermal energy and can modulate its speed based on the variation in solar radiation with time from morning to evening. The generated thermal energy is stored in the thermal storage system and a part of the generated electrical energy is stored in electrical storage system to operate components which will be required to function in absence of sunlight i.e. milking cycles which take place in late evenings and early mornings. This storage system has the capacity to chill milk of two consecutive milking cycles, in the absence of sunlight. The capacity and design of the thermal storage system is pre-calculated based on the cooling capacity required for cooling the quantity of milk obtained in two milking cycles. The refrigeration system operates continuously during the day and keeps on generating thermal energy till solar radiation is available, after which it stops automatically.
The thermal energy storage system is designed such that minimum loss of stored energy occurs and the storage is sufficient to chill milk obtained from two milking cycles. Electrical energy generated from solar power is stored to operate the components of the system in the absence of solar and grid power. The thermal energy is stored by converting a food grade fluid from liquid state to solid state in which the thermal energy is stored in the form of latent heat.
After the first milking cycle, when the procured fresh milk is added to the bulk milk cooler module, the temperature in the bulk milk cooler is more which is sensed by the controller. The controller then initiates the main control panel which operates the refrigerant circulation pump, taking power from the battery in which electrical energy is stored during the day from solar panels. This pump transfers the refrigerant to the bulk milk cooler and chills the milk rapidly from approximately 350C to 40C. After the milk achieves 40C temperature, the controller senses this temperature and stops the circulation pump. The chilled milk is stored in this condition till the next milking cycle. During the 2nd milking cycle, as soon as milk is added to the bulk milk cooler, the controller senses the rise in temperature and starts the refrigerant circulation pump due to which the milk starts chilling. The circulation stops once milk attains the desired 40C temperature. At any time during the storage of the milk, if the temperature of the milk rises above 50C, the controller automatically starts the circulation pump which keeps circulating the refrigerant till the milk is chilled back to 40C.
In the absence of solar power (for eg. during monsoon season), the system has a provision to run on grid power too, such that the milk chilling process is not disturbed or delayed.
The components of the system of the proposed invention are as follows:
1 – Thermal storage system
2 – Bulk Milk Cooler module
3 – Solar operated refrigeration system
4 – Refrigerant pump
5 – Condensing unit/refrigeration system mounting stand
6 – System operation and control panel
7 – Battery
8 – Inverter
9 – Solar Panel Mounting Structure
10 – Solar Panel
11 – Milk Transfer Pump
12 – Computer, Fan and Tubelight

Fig. 1 gives the layout drawing of the solar operated bulk milk cooler module with thermal storage system. This diagram displays the components of the Bulk milk cooler module of the present invention which shows that the thermal storage system (1) is connected to the bulk milk cooler (2) through the refrigerant pump (4) which pumps in the refrigerant from the thermal storage system into the bulk milk cooler for cooling the milk to 40C. Milk is transferred through the milk transfer pump (11). The solar operated refrigeration system (3) has a condensing unit stand / refrigeration system mounting stand (5) on which the system is mounted. Battery (7) from which stored power will be used to operate refrigerant pump and inverter (8) to charge the battery, are provided to operate the system using conventional source of electricity in absence of solar energy. System operation and control panel (6) is used to control and operate the entire refrigeration system as well as the bulk milk cooling module. In the absence of solar energy, this panel can be used to switch to conventional source of energy (A.C Power supply). Computer, fan and tubelight (12) are provided in the module for proper visibility and for providing cooling to the computer systems.
Fig. 2 gives the three dimensional view of the solar operated bulk milk cooler module with thermal storage system which shows all the components of the system housed within the module over which are arranged multiple solar panels (10) on solar panel mounting structures (9) which harness the solar energy and produce electricity (D.C. power). This D.C. power is used to run the refrigeration system to generate thermal energy which is later stored in the thermal storage system.
Fig. 3 gives the piping and instrumentation diagram of the complete system wherein the electricity generated from solar power is passed to the solar operated refrigeration system which has a condensing unit comprising of a sight glass, filter/drier, split valve, receiver, condenser and compressor wherein the refrigerant is sucked in the compressor to compress it. This raises the temperature and energy of the refrigerant which is sent to the condenser for condensation. The condensed refrigerant is passed through the receiver, split valve, filter/drier and sight glass and discharged to the thermal storage system. The circuit diagram of the thermal storage system is provided in the fig.3. This thermal storage system stores the energy which is used to chill the added fresh milk after each milking cycle. This energy is passed to the refrigerant pump which pumps in the refrigerant in the bulk milk cooler for chilling the milk.
Fig. 4 gives the table displaying the charging cycle of the solar thermal storage system which shows that the thermal storage system is charged to 100% between 10 am to 4 pm in the presence of sunlight wherein the temperature decreases from 00C to -50C while the D.C. voltage generated per hour is between 720 to 760 volts.
Fig. 5 gives the table displaying the milk chilling cycle after the 1st milking cycle which shows that when milk is added to the bulk milk cooler after the 1st milking cycle, it takes 3 hours to chill 500 liters of milk fed in the bulk milk cooler at 350C and bring its temperature down to 40C. Fig. 6 gives the table displaying the milk chilling cycle after the 2nd milking cycle which shows that when additional 500 liters fresh milk procured after the 2nd milking cycle is added to the bulk milk cooler which already contains 500 liters milk at 40C, the temperature of the 1000 liters milk in the bulk milk cooler rises to 100C. As shown in the table, it takes one and a half hours to bring down the temperature of the milk to 40C.
Fig. 7 gives the table displaying the electrical load and operational charges of a conventional bulk milk cooler of 1KL capacity running on grid power. As the conventional milk collection systems operate on grid supply, a diesel generator has to be provided with the system so that in absence of grid supply due to load-shedding, failures or any such reason, milk, which is a highly perishable product, is chilled and maintained at the chilled temperature soon after its procurement. As shown in the table, the cost of operating a bulk milk cooler of 1 KL capacity using grid electricity is Rs. 4724/- per month which can be saved using the system of the present invention. Moreover while using grid electricity, a diesel generator set of 10KVA needs to be installed which costs around Rs. 1,72,000, which too need not be installed while using the system of the present invention thereby saving money.
Fig. 8 displays the table displaying the electrical load and operational charges of a conventional bulk milk cooler of 1 KL capacity running on Diesel Generator (D.G.) set. In remote areas where grid power is still not available or partially available, milk chilling is done using a diesel generator (D. G.) set. As shown in the table, the total cost of operating a bulk milk cooler of 1 KL capacity using D.G. set is Rs. 34816 per month which can be saved using the system of the present invention. Moreover a diesel generator set of 10KVA needs to be installed which costs around Rs. 1,72,000. These expenses and their maintenance costs are saved while using the present invention.

The solar operated bulk milk cooler module with thermal storage system of the present invention is highly advantageous as it provides a bulk milk cooler module which is completely operated using solar energy. The system also has a thermal storage system which stores the thermal energy for chilling the milk procured after two milking cycles. In India, milk collection is commonly done in remote villages where cattle rearing is a primary occupation. In many of these villages, grid power is either unavailable or partially available, such that it may not be available at the time of milk collection. Due to this drawback, either diesel generators need to be used for chilling the milk or milk needs to be transported to a nearby chilling centre which may lead to deterioration in the quality of milk due to this delay or during transportation. As the system of the present invention uses solar energy for chilling the milk, dependence on grid electricity is reduced and milk can be chilled at remote locations at the site of collection. Due to this better quality milk is collected at no operational costs. Moreover one of the key features of the proposed invention is that it facilitates rapid chilling of the milk wherein the milk collected is rapidly chilled from 350C to 150C, as compared to conventional chilling systems such that bacterial growth does not occur and the shelf life of the milk increases. The system of the present invention can be easily assembled and automatically operated as well as is economical.

Although the preferred embodiment as well as the construction and use have been specifically described, it should be understood that variations in the preferred embodiment could be achieved by a person skilled in the art without departing from the spirit of the invention. The invention has been described with reference to specific embodiments which are merely illustrative and not intended to limit the scope of the invention as defined in the claims.
, Claims:We claim,
1. A solar operated bulk milk cooler module with thermal storage system which uses solar energy for operating all the components of the bulk milk cooler which mainly comprises of thermal storage system (1), bulk milk cooler module (2), solar operated refrigeration system (3) with capability to run at variable speed depending on variation in generated D.C. voltage, solar operated refrigerant pump (4), system operation and control panel (6), solar panels (10) and solar power operated milk transfer pump (11);
wherein solar energy is harnessed through the solar panels (10) mounted over the bulk milk cooler module on solar panel mounting structures (9) which is used to generate electricity for operating the refrigeration system and also generate thermal energy which is stored in the thermal storage system (1); and
wherein when milk is added to the bulk milk cooler module (2), the controller detects the temperature of the milk automatically and utilizes the thermal energy stored in the thermal storage system (1) to chill the milk to 40C by pumping in the refrigerant in the milk through the refrigerant pump (4).
2. The solar operated bulk milk cooler module with thermal storage system as claimed in claim 1 wherein the solar operated refrigeration system (3) has a compressor which sucks in the refrigerant and compresses it with the help of the received solar energy, thereby raising its temperature and energy and a condensing unit which condenses the refrigerant present in the gaseous form into liquid form which is stored in the thermal storage system (1) to chill the milk.
3. The solar operated bulk milk cooler module with thermal storage system as claimed in claim 1 wherein the control system in the refrigeration system automatically modulates the thermal energy generation based on the variation in solar radiation with time.
4. The solar operated bulk milk cooler module with thermal storage system as claimed in claim 1 wherein the capacity and design of the thermal storage system is calculated based on the quantity of milk to be added to the bulk milk cooling module for two consecutive milking cycles and the amount of cooling required to chill the milk and maintain it at 40C.
5. The solar operated bulk milk cooler module with thermal storage system as claimed in claim 1 wherein the media used to store thermal energy is a food grade fluid.
6. The solar operated bulk milk cooler module with thermal storage system as claimed in claim 1 wherein the system has a provision to run on grid power in absence of solar power.