Essay Example on Heater and Wind Machine One of the Active frost protection Method

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Heater and Wind Machine One of the Active frost protection method is the Heater to help replacing energy losses from plants we must provide a heat source the heating source either from operate as open fires or using one of the Heater types such as Return stack oil fuel heaters by increase the temperature of metal objects the released heat from the heaters transfer to the plants by convection and from the heater the radiant energy travels directly to the plants due to the large amount of smoke and emissions some heaters may not be legal to use to make sure that all the energy losses are replaced we should add enough heater to cover all the crop area The orchard heaters and wind machines are extremely high costs labor intensive for example Labor required to refill liquid fuel heaters and environmental pollution is a major disadvantage Koc et al 2000 the mechanism of orchard propane heaters by circulating hot air mixing up the cold air near the ground with the latter being able to warm up the ground temperature up to 21ºF 6 1 C Orchard heaters replace the energy loss by adding the heat to the orchard However orchard heaters are not an efficient method as a large portion of energy is lost in the sky wind frequently interferes and the heaters contribute to air pollution for this reason the oil fired heaters have been banned in many areas 



Evans 2000 and the heat loss of orchard heaters may reach up to 85 due to radiation to the sky by convection above the plants The use of oil fired heaters is banned in many areas and air pollution by smoke can be a significant problem Poling 2008 The heaters can be used alone to prevent the frost damage and temperature drop up to 2 5 C Stamps et al 2010 reported that using combustion heaters for the Foliage Plants in shade houses and Greenhouses that the disadvantage high cost of operation fuel and maintenance other disadvantages of burning fuel the environmental pollution if there is no smoke ventilation inside the greenhouse and shade house the environmental contamination because of the fuel spills or leakages and releases An early Electrical Heater frost protection method first developed by French patent Heurteau 1998 by using electrical heating cables were wrapped to the vines plant the mechanism by conducting the heating from the electrical heater cable to vine wood then to all the other parts of plant Lamb 2009 also successfully modified Electrical Cable Heaters for the early flowering from frost damage by reducing the frost damage to 30 but this work for smaller vineyards During the mechanical harvesting it is hard to use the electrical heater cables and during the vines clipping it would be necessary to prevent the cables from damage while mechanical and hand harvesting it may be necessary to remove the cables from the vines Figure 3 Top Picture a showing vine tree with electrical heater cable red Picture b showing the electrical heater cable through the entire vineyard Lamb 2009 Massah Noorolahi Torki 2011 It has been shown experimentally that the developed

Electrical heater that used for frost protection will reduce the spring temperature by 6 C which will help to prevent frost damage by using two outer layers of waterproofing rubber and with glass wool layer inside there are thermal wires for the tree side layer by convection and radiation the heat will transfer from the heater to the tree The other kinds of heaters the Oil burn heaters which is free standing unit connected to oil pipeline network or natural gas propane and liquid petroleum controlled by adjusting the central pumping station by controlling the rate of burning Poling 2008 have shown that About the 75 of the heat energy from stack heaters by heating the air because of the hot gas emitted to the crop area and mixing with air and with inversion layer and the other 25 of energy released by radiation by transferring from the heater to the plant The wind machine disadvantage such as noise which is a big problem for growers so we can't install it close to the residential area we can say that it is highly installation cost if we compare it with other methods it is not working if there is no temperature inversion also we can use it if there wind speed exceed 5 miles hour or the weather had supercooled fog and need maintenance the temperature reduced to the wind machine between 1 4 C it means that it is not practical when we need to raise that temp more than 4 C Poling 2007 it will not effective under freeze conditions if it used under this condition it may increase the buds injury and damage the wind machine fan also the wind machines relatively expensive to purchase and install In the weak inversion weather conditions the wind machines are less efficient for cold injury to reduce the cold damage the heater need to add to the wind machine to help to reduce the cold injury Snyder et al 2005 reported that the Heaters will not an effective method to prevent the frost damage when there no inversion and high speed of wind or when there is a little inversion for up to 4 5 ha crop area needs to install wind machine with about 75 Kw this will cost about 20 000 for each wind machine in additional to installation labor fuel cost the fuel cost is 5 10 of fuel used by the fuel oil heater system


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