Improving the energy consumption of compressor with SunTrac USA's Hybrid Air-Conditioning
In India there are many application for HVACR System used for different purposes such as Residential cooling, Industrial cooling & Cold rooms etc.,Also nowadays there are new requirements of Clean rooms emerging with many industries taking the Vendor-ship of European companies,They come with European Standards for manufacturing their products.
As with the case of Jay Precision Pvt. Ltd. ,Their branch of Patalganga,Panvel has Teamed up with Bandai Namco Entertainment to manufacture their toys in India. The manufacturing process requires the Air-Quality level below 50 Microns Meaning that the contaminants more than 50 Microns should be avoided in the manufacturing area and the temperature of the manufacturing area should be maintained at 24+/-2 degree Celsius. The manufacturing area is 2000 Sq. Ft. and has many Heat producing machines which caters to around 40 Tons of Air-Conditioning.
For satisfying their Air-Conditioning requirement they have installed 5 X 8.5 Ton condensing unit to an AHU of 12000 CFM. For Economical operation of their condensing unit and saving in the bill for long term purpose this is my attempt to reduce the bill of operation with the help of SunTrac USA's Hybrid Air-conditoning
Terminology
The above image is a representation of their patalganga factory in Panvel. The 8.5 ton compressor is installed on the roof of their factory and the refrigerant piping is supplied to the Ceiling suspended AHU. The compressor are manufactured by Carrier and have R-22 Refrigerant in them.
Methodology
The proposal for economical working of HVAC System comprises of cutting the outlet pipe of the compressor of outdoor unit and then feeding it to the SunTrac panel as shown in the above image. The outlet of the panel is then brazed to the condenser inlet pipe. The Refrigerant in this case being R-22 is heated in SunTrac Panel and then fed to the condenser
How does it work ?
The use of Solar Panels for air-conditioning system is not new to the industry,the Vapor-Absorption Refrigeration cycle uses NH3 (Ammonia) as a refrigerant (Strong solution) which is heated in the solar panel heaters and then absorbed by water (Weak solution) and then pumped to the expansion valve for refrigeration effect.
But this system is inefficient in many ways as the solar panel heaters does not track the the movement of sun with its azimuth angle meaning that the solar reflectors are not perpendicular to the sun throughout the day.Thus, the radiant heat of solar rays are not efficiently transferred to the refrigerant in the system.
To overcome this problem SunTrac solar has invented a panel with parabolic reflectors enclosed in a glass shield which is then mounted to building structure so that each reflector is perpendicular to the the sun throughout the day.
The refrigerant in the refrigeration cycle (R-22) leaves the compressor with high pressure and high temperature,it then proceeds into the solar thermal panel where additional heat and pressure is added to the refrigerant using radiant energy of sun furthermore when the refrigerant leaves the compressor it is not completely in gaseous state, a partial state of liquid is present and when the radiant energy of sun is applied to the refrigerant the state of refrigerant fully changes from partial liquid to completely gaseous.The high pressure and high temperature refrigerant gases are then admitted to the condenser, the increase in temperature of refrigerant caters to efficient heat exchange to the surroundings in the condenser.This system allows the compressor to be operated at lower stage thus reducing the electricity needed to operate and in-turn reduction in the electricity bills.
The solar tracking of panel caused by a motor energized from a solar switch having light sensing devices which also tracks the sun's position so that in one position of the sun the switch does not energize the motor but in second position the switch receives solar radiation and energizes the motor which changes the angle of the parabolic reflectors.The tracking of reflectors provides efficient radiation which are used to heat the refrigerant.
The solar thermal panel consists of temperature sensors to efficiently control the heat added to the refrigerant it allows the solar thermal panel to maintain the temperature of refrigerant flowing into the system. when the temperature of the refrigerant exceeds the set value, the parabolic reflectors swirl away from the perpendicular angle to the sun reducing the radiation energy being transmitted to the refrigerant
thus reducing the temperature of the refrigerant. when the temperature of the refrigerant falls below the set value the reflectors swirls and comes in a perpendicular angle with the sun to transmit the radiant energy.
The temperature sensing system consists of no. of temperature sensors which measures inlet manifold temperature, outlet discharge temperature, motor temperature, panel temperature and ambient wind temperature which are used to determine current flow, voltage and power from p-v cells to solar panels.
In-addition the east limit,west limit,the radiation on a given surface area in a given time are measured. Also the time from the last movement of solar panel is measured to make sure that the solar thermal panel is not stuck at any point.
To Summarize
This hybrid-thermal approach displaces a portion of the mechanical energy used by compressors in a refrigeration cycle, which keeps the compressor in low stage, low range or low capacity, while delivering full and part-load cooling requirements. This effect creates significant energy savings.
