Scope

The following processes in automobile manufacturing have scope for integrating solar heating:

  • Phosphating Process
  • Parts Washing
  • Paint Shop Drying
  • Sludge Drying
  • Effluent treatment

Solar Integration for Phosphating

Phosphating process is used as a pretreatment method in conjunction with another method for corrosion protection. Phosphate coating is usually applied to the components by immersing them in solution baths as shown below:

Phosphating auto parts

Such baths use electrical heaters or diesel/furnace oil fueled boiler for maintaining the bath temperature around 90 deg C. Concentrating Solar Thermal (CST) technologies can be used to provide the heat required for phosphating process without any change to the process.

Parts Washing using Solar Heat

Parts washer is used to remove contaminants or debris such as dirt, grime, metal chips etc. from the components before they are assembled. These washing machines today used electrical heaters to raise the temperature of the water being used for washing.

Compound Parabolic Collector

The temperature of the water is between 70-90 deg C and this can be provided by Compound Parabolic Collector (CPC) shown above. CPCs can be installed even on the shed roof. Solar heat can also be used during non-solar hours by incorporating hot water storage tank.
CPCs provide low concentration that is suitable for providing pressurized hot water upto 120 deg C. They do not require tracking and can utilize even diffuse radiation from sun. The maintenance requirements are also low and hence, are appropriate for low grade heat requirements (70-120 deg C).

Solar Paint Shop Drying

Paint shop is used for many automobile components, machine components and other made gadgets use paint shop for resistance against exposure to element of nature like chemicals, moisture, rain, dust, and for having an aesthetically appealing product. Paint curing requires heat, mostly in the form of hot air. Today fossil fuel based heating is used in paint shops, to generate curing air temperatures ranging from 80° C to 150° C. Atmospheric air being taken in by the oven can be fed with air pre-heating using solar concentrators.
CPCs or Parabolic Trough Concentrators (PTC) as shown below can be used for such requirements with a suitable thermic fluid to air heat exchanger.

Parabolic Trough Concentrator

Solar Sludge Drying

Waste water sludge needs to be dried to minimize the its mass to reduce the sludge hauling and disposal costs. Today most industries dry sludge using open evaporation method. However, this process can be significantly accelerated by using solar heat in different forms.
Oorja integrates its expertise in Radiant Heating systems and Heat Pumps to design and implement a sludge drying system that further enhances the rate of drying of the sludge.

Solar Effluent Treatment

Many companies are now adopting Zero Liquid Discharge (ZLD) policy for treatment of effluents and a Multi Effect Evaporator (MEE) is generally being used to treat waste water and reuse it for process or other plant needs. MEE requires steam temperature of which is dependent on the number of stages of the evaporator. Today the MEE uses fossil fuels like diesel or natural gas or furnace oil.
Solar Concentrators can provide steam required for MEE to waste water treatment.

steam Boilers

The solar field can be integrated with the existing boiler to operate the system in a hybrid manner. Oorja can provide all required engineering for integration of existing boiler with solar concentrator field.

About Oorja Energy Engineering

Oorja Energy Engineering is a complete Cleantech Heating & Cooling solutions company. We offer energy efficient and renewables based products and solutions for industrial and commercial heating and cooling requirements.
Oorja is a Ministry of New and Renewable Energy (MNRE) approved manufacturer of Concentrating Solar Thermal (CST) systems. We can design & implement cleantech heating and cooling solutions for your specific requirements.

Heating in Food Processing

The following processes in food processing have scope for integrating solar heating:

process_temp_table.png

Solar Drying

Drying is a part of most food processing industries and currently expensive fuels like electricity or diesel are used for drying. Concentrating Solar Thermal (CST) technology can be used in conjunction with the existing drying system to reduce the fuel consumption.

CST systems are versatile and can be integrated with drying systems that use steam or hot water or thermic fluid.

Pressurized Hot Water with Solar

Solar Compound Parabolic Collectors (CPCs) can be used to generate pressurized hot water that can be used for pre-heating Boiler Feed Water (BFW).

pre-heating_boiler_feed

Pasteurization uses steam or thermic fluid for generating temperature around 90 Deg C to 150 Deg C using fossil fuel based heating systems. Concentrating Solar Thermal (CST) technologies can be used to provide the heat required for pasteurization process without any change to the process.

Solar Pasteurisation in Milk Industry

Solar Boiler

Parabolic Trough Concentrator (PTC), like the one shown below, can be used to generate temperatures up to 350 deg C and can be used as solar boiler. The heat generated from such solar boiler can be used for various food processing needs.

parabolic trough concentrator

Heat from the PTC field can be provided to the processes using any of the following steps:

  • Use thermic fluid in the PTC field and use hot thermic fluid to generate steam in a heat exchanger.
  • Steam can then be given to the process directly or can be integrated into a common steam header.

Since the output from solar field will vary depending on the radiation available, it is critical to design appropriate controls for efficient integration of solar and conventional boiler outputs.

Solar Heat can also be stored in an appropriately sized storage system for extending the usage of heat to non-solar hours.

Solar Sludge Drying

Oorja’s Solar Sludge Drying solution enhances the drying rate of an open pit sludge drying. Reducing the water content from the sludge significantly reduces the associated hauling and disposal costs.

Oorja’s solution integrates its expertise in solar heating, radiant heating and heat pumps to offer a unique solution that can help organisations reduce the drying time of the sludge significantly.

solar sludge drying

About Oorja Energy Engineering

Oorja Energy Engineering is a complete Cleantech Heating & Cooling solutions company. We offer energy efficient and renewables based products and solutions for industrial and commercial heating and cooling requirements.

Oorja is a Ministry of New and Renewable Energy (MNRE) approved manufacturer of Concentrating Solar Thermal (CST) systems. We can design & implement cleantech heating and cooling solutions for your specific requirements.

Radiant Cooling for Industrial Buildings

There are primarily three sources of heat in an industrial building:

  • Solar Heat Gains through Structure
  • Internal Machinery, Lighting & Occupancy
  • Ventilation

Of the above, solar heat gains forms much of the load during peak season, especially if the roof is made of GI or Galvanium sheets. The thermograph below shows the temperature profile for inside surface of the roof of an industrial building.

Thermograph_hot

The roof absorbs all the solar radiation during the day. However, a metal roof has very low thermal mass compared to a RCC roof and therefore, the rise in temperature of the roof is much higher for a metal roof.

Though insulation can reduce the amount of solar heat gains, the surface temperature of the roof is still significantly high during summer months.

Radiant Cooling

Cooling is the process of taking the heat away and there are only three ways of heat transfer as shown below:

Types of Heat Transfer

Air conditioning uses convection as a means of heat transfer whereas Radiant Cooling uses radiant heat transfer as the primary means of heat transfer. Radiant Cooling uses “heat sinks” in ceiling or floor to take the heat away from the space as shown below.

Radiant Cooling

Radiant Ceiling Cooling

Radiant Ceiling Panels have been used in many industrial buildings in Europe & North America for heating and cooling. Oorja has poineered and provides radiant cooling solutions.

Radiant Ceiling Cooling

These panels act as heat sinks or sources depending on whether they are being used for cooling or heating. These cooling panels block the heat radiated from the metal roof and absorb the heat from the space below, thus cooling the space.

Thermograph_cool

The above thermograph shows the radiant panel temperature that workers are exposed to compared to much higher temperatures without them.

Radiant Floor Cooling

Radiant Cooling can also be done by embedding specialized pipes in the floor to make it a heat sink as shown below.

radiantCooling_Floor

Such installation can be planned for greenfield projects.

Energy Efficiency

Radiant Cooling offers 30-50% energy savings over conventional air based cooling systems due to:

  • Savings on fan motors due to very low air recirculation requirement.
  • Savings on chiller operation due higher temperature water requirement (16-20 deg C) compared to 7 deg C in conventional system.

About Oorja Energy Engineering

Oorja Energy Engineering is a complete Cleantech Heating & Cooling solutions company. We offer energy efficient and renewables based products and solutions for industrial and commercial heating and cooling requirements.

Oorja is a Ministry of New and Renewable Energy (MNRE) approved manufacturer of Concentrating Solar Thermal (CST) systems. We can design & implement cleantech heating and cooling solutions for your specific requirements.

Air conditioning and refrigeration today consumes more than 50% of the energy for many buildings. India’s Air Conditioning penetration is between 3-6% today against the world average of 60%. With increased affordability of air conditioners, there is going to be severe strain on the availability of electricity. Therefore, cooling systems that do not depend on electricity have to be adopted.

Adsorption cooling uses hot water to provide chilled water used for central air conditioning. The source of hot water required for adsorption cooling can be either solar or some waste heat source, thus reducing the cost of electricity significantly for cooling.

The diagram below shows the working of an adsorption chiller:

Adsorption ChillerAdsorption Chiller

Oorja is now manufacturing adsorption chillers in India and can assist you in any of your solar cooling or waste heat based cooling projects.

There is a growing emphasis on utilising solar energy for industrial processes, cooking and other heat related processes to achieve energy security as well as to combat the menace of climate change and global warming. While there is a larger focus on power-generation aspect of solar energy, there are greater opportunities to deploy solar energy for heating requirements.

The following industries can greatly benefit from adopting solar technologies for their heating needs:

Dairy Food Processing Textiles Pharmaceuticals
Biotech Automotive Leather Hotels
Hospitals Beverages Paper & Pulp Jute

The following processes can benefit from utilization of Solar Heat:

Cooking Pasteurisation Laundry Autoclaving
Drying Boiler Feedwater Preheating Debacterisation Desalination
Industrial Process Heat Cooling Electricity Generation Baking
Oorja offers the following three Solar Concentrators for different uses:
1. PTC 300: can generate heat up to 300 deg C using thermic fluid and up to 250 deg C with steam.

Parabolic Trough ConcentratorLarge Aperture Parabolic Trough Concentrator (PTC72)

2. PTC18: can be used generating heat up to 200 deg C:

Rooftop Parabolic Trough ConcentratorRooftop Parabolic Trough Concentrator

Of three modes of heat transfer – Conduction, Convection & Radiation – the least understood is mode is Radiation, especially with regard to human thermal comfort. Thermal radiation is electromagnetic radiation emitted from the surface of a body as a result of its temperature. The picture below shows three modes of heat transfer:

Radiant Heat Transfer

As can be seen from the above diagram, Radiation does not require any medium unlike Conduction and Convection.

Radiant Cooling is based on the physical principle that bodies with varying temperatures exchange thermal radiation until an equilibrium is achieved. The principle of Radiant Cooling has been around in nature and human beings have using this principle knowingly or unknowingly for ages:

  • Inner walls of the caves are at a lower temperature as the heat from solar radiation does not percolate down to these walls. In addition, these walls are cooled due to the water streams, vegetation etc.
  • Snow-packed walls in buildings in 8th century Mesopotamia
  • Lotus Mahal in Hampi has intricate channels along the walls through which water flowed to take away the heat from the interior.

Modern Radiant Cooling follows the same principle to cool a floor or ceiling (or even walls) by absorbing heat radiated by the rest of the room. As can be seen in the diagram below, a Cooled Ceiling acts as a heat sink for all radiant heat sources in the room (human occupant, solar radiation, equipment, walls etc.).

Radiant Cooling Room

Note that Radiant Cooling is not a “high side” system that replaces Chiller. Radiant Cooling is a “Low Side” technology that relies on chilled water pipes to distribute cooling throughout a building rather than using chilled air and ductwork.

Radiant cooling systems rely mainly on the direct cooling of occupants by radiative heat transfer because the pipes, which are commonly run through ceilings, maintain the surface at temperatures of about 20-22 deg C. Through radiative heat transfer, people in the room will emit heat that is absorbed by the radiant cooling surface.

To manage indoor humidity levels and air quality, a separate ventilation system to supply fresh air is needed. Zoning of building can also be done due to ease of controlling flow of water.

Click here to know how Radiant Cooling works?

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