System of protection of gardens and vineyards from frosts

Project

 "System of protection of gardens and vineyards from frosts"

Introduction

The main scourge of wine growing and gardening are cold winters, late spring and early autumn frosts.

Especially suffer from frosts vineyards and the gardens located in lowered places and at feet of slopes . Fabrics of young escapes of grapes and young leaves are damaged at a temperature a minus 1 degree С. The late frosts which have come after blooming of kidneys, during growth of young escapes are especially dangerous.

In confirmation of them are frosts of 2012 in Krasnodar Krai, Russia were rather harmful for vineyards and gardens. Low temperatures kept more than two weeks and fell in some areas to - 25C.

Freezing of the soil reached 40-45 cm. The considerable damage was brought by autumn and spring frosts. Completely the considerable part of open vineyards was lost. And, according to forecasts, the shortage of a crop will make nearly a third - about 40 thousand tons of amber berry. In money it is more than 20 million US. There will be no also full-fledged crop of an apricot, a peach, a cherry plum and so on.

Unknown frosts destroyed more than 80% of vineyards of the republic.

To hard frosts underwent not only plantations of Krasnodar Krai, but also Stavropol Territory. By estimation, losses of wine makers in the south of Russia can make to a half of all crop of grapes. Wine-growers need to worry not so much about the current crop, how many about long-term damage to vineyards. On restoration of wine farms years, especially after severe winters be required.

However it is necessary to notice that similar frosts, critical for rewintering of grape plants, happen in the southern areas of wine growing and gardening rather often: in different areas – time in three years or five years, and frosts in the first half of April happen almost annually. In the second half — is much more rare, once in 2-3 years at early spring.

Justification of need of work

Protection against freezing is an important element of a commercial component of wine growing and gardening.  Almost all vineyards and gardens in various regions of the world can be damaged to spring and autumn frosts.  Prevention of freezing can be reached at the expense of use of passive or active methods.  Passive methods, such as a platform choice, a variety of a choice of grades of grapes and fruit-trees, a choice of agrotechnical technologies are less expensive, than active methods, but can provide only a few extents of protection.  On the other hand, active methods (of heaters, a wind car or their combinations) are more expensive, but can give 2,8-3,3 °C of protection in ideal conditions. 

The combination of passive and active methods, most likely, is the most effective method of protection against freezing.

Physical process of formation of abnormally low winter temperatures at night and especially in the morning (so-called "morning performances"), spring and autumn frosts in principle same.  It is connected with process of formation of temperature inversion in ground layers of the atmosphere. 

Temperature inversion – (from lat. inversio — shift), air temperature increase with height in some layer of the atmosphere, instead of its usual decrease. Meets in a ground layer of air and in these cases ground temperature inversion is called. Ground temperature inversion are most often formed in windless nights (in the winter sometimes and in the afternoon) as a result of the intensive radiation of heat by a terrestrial surface that leads to cooling as her, and an adjacent layer of air. Besides ground temperature inversion arises at night cooling of air over the soil, a snow and ice cover, a congestion of cold air in hollows and valleys, inflows of cold air. Thickness ground temperature inversion makes tens - hundreds meters. The increase in temperature in an inversion layer fluctuates from the tenth shares of degrees to 15-20 °C and more.

Heat transfer from a terrestrial surface in an upper atmosphere is carried out by three ways: molecular heat conductivity, thermal convection and by means of turbulent hashing of air. Molecular heat conductivity of air is very small therefore this way of heating of the atmosphere doesn't play a big role. Thermal convection and turbulence in the atmosphere in this regard has the greatest value.

The origin of temperature inversions happens various. They can be formed as a result:

• runnings off of the cooled air from slopes of mountains in the closed hollows,

•  owing to the strong radiation of a terrestrial surface (radiation inversion), 

• at advection of warm air, in usually early spring, over snow cover (snow inversion),

• at approach of cold mass of air on warm (front inversion), thanks to turbulent hashing of air (turbulence inversion).

Radiation frosts are formed as a result of cooling at night a spreading surface owing to terrestrial radiation or because of running off from slopes of heights in falls of cold air with a temperature below 0 °. Emergence of radiation frosts is promoted by lack of clouds at night, small humidity of air and windless weather.

Advective frosts result from invasion on this or that territory of cold air masses (the Arctic or continental polar masses). In these cases of a freezing have steadier character and cover the considerable areas.

However most often disturb radiation frosts.  For a frost the clear and still night when effective radiation from a surface of the soil is great is necessary, and turbulence is small also the air which is cooling from the soil, isn't transferred to higher layers, and is exposed to long cooling.  Such clear and calm weather is usually observed in internal parts of areas of high atmospheric pressure, anti-cyclones.  The surface of the soil and ground layers of air thus quickly cool down. 

Radiation frosts cover small sites. Besides, they have prizemny character: height of a layer of air with negative temperatures seldom exceeds 1,5 — 2 m. Therefore the frost quite often strikes gardens, kitchen gardens or vineyards in the low district while on hill slopes they remain intact.

 The radiation (local) frosts which are caused strong night radiation of heat from a surface of the soil and plants, happen usually small (to –1.–2 degree) and short-term. The frost is a short-term decrease in temperature of a surface of the soil and a ground layer of air during vegetation to level of 0 °C and below. At a temperature below 0 °C water, mainly from which plants consist, freezes, and being formed кристаллики ice damage their fabrics and a cage.

For many years producers of grapes and gardeners looked for various options to try to prevent damage from frosts - a smoke, water, a wind or combinations of each of them.

Measures of fight against frosts can be divided into agrobiological receptions and ways of direct protection of plants.

The choice of favorable sites belongs to agrobiological receptions, first of all. The grapes landed near walls of buildings and constructions, fences, are damaged less, than on an open site. To decrease in intensity of frosts on peat soils apply "peskovaniye" (superficial drawing a layer of sand 5 - 8 cm thick).

Direct protection of plants against frosts is use of various materials and adaptations for decrease in intensity of radiation of heat from the soil in the atmosphere. For example, to protect plants from weak and moderate frosts, them cover for the night with various materials. For this purpose use paper, a film, different nonwoven fabrics.

The most known and widespread way of fight against frosts is smoking. From the moment of blooming of kidneys carefully watch temperature at night. Ignition of heaps and checkers begins when air temperature over level of the soil will fall to plus of 1 degree. Smoking in an hour after sunrise comes to an end.

However today it is well known that protection happens from heat allocated from combustion, instead of from a smoke. The size of an average particle of a smoke makes less than 1,0 mm that reduces radiation in the visible range (0,4-0,7 mm), but influences transfer of long-wave radiation a little. Thus, long-wave radiation up from a surface generally passes through a smoke without absorption. Thus, the smoke has insignificant impact on long-wave radiation at night and, therefore, has not enough advantage for protection against freezing. In principle, the smoke brings not enough benefit (or in general any advantage) but only pollutes air. The most correct approach at such way of protection against frosts - to create the maximum thermal efficiency of combustion.

In the southern areas of wine growing to this purpose apply soil watering.   This reception increases temperature of a ground layer of air on 2 — 3 °C.   However, to reach such effect, on 1 sq.m it is necessary to pour out not less than 50 (!) l of water.  

The simplest and effective method of fight against temperature inversion (at protection of protection of gardens and vineyards against suddenly come frosts) - a turbulent (helicopter) way. Helicopter it is called because now in many regions of the world helicopters are used for hashing of warm higher layers of air with ground colder. The screw of the helicopter represents the mobile fan with the power plant. Using onboard indexes of temperature of external air, helicopters find zones of warm air and screws direct air streams on agricultural grounds. The helicopter way of fight against frosts has a number of advantages. First, it is highly mobile, depends on change of the direction and speed of a wind a little and allows to liquidate temperature fall on the big areas. Secondly, this way appears ecologically much purer, than smoke screens. It is known that traditional methods of fight against frosts – fumigating and smoke – lead to that a large number of aerosols is entered into air, a soot, a smoke and other harmful substances.

However mass use of helicopters, of course, is an unacceptable method. Besides, the engine of the helicopter is rather strong pollutant of air.

In recent years more effective and economic measures for fight against frosts in the spring and in the fall are applied. One of them is use of powerful fans which mix warm air (located above) with cold (located below).

On vineyards unique properties have a wind car. In the spring, a wind - the car protects a kidney fruit, in the fall it protects leaves of plants from freezing which help to bring completely mature berries to a maximum level of sugar. In the winter help to protect rods and roots from a vymerzaniye.

The first a wind car for protection against freezing, as we know, appeared in California in the 1920th years. On the first a wind cars wooden support with the power unit on tower top were used. Thousands wind cars on five continents in the USA, Chile are now established, to Australia, New Zealand, Portugal, Japan, Spain, Argentina and Mexico, etc.

In 1957 specially new aerodynamic schemes of fans are developed for movement of large volumes of air with a smaller speed, the covering of the protected area from 5 to 10 hectares on unit doubled at the same power. Today, achievements and improvements in the field of aerodynamics of fans continue to develop, the covering of the protected area became more.

Axial fans with a diameter of driving wheels of 12-25 meters are actually applied. Air movement in them happens at an angle to a horizontal axis and at the same time for some time they make turn round a vertical axis. Thanks to it they can protect rather big area from frosts.

The Ausvat Pty Ltd company uses the so-called SiS technology where axial fans too the big sizes are applied to pumping out of cold layers of air from the bottom layers of the atmosphere where on their place warmer layers preventing frosts arrive.

However the Wind car or SIS systems have as well serious shortcomings:

•  High price Wind car. 

• Costs of service - as a rule, for one big the Wind car it is necessary 65 to 75 kW for each site from 4,0 to 4,5 hectares.

• The temperature effect decreases approximately in inverse proportion to a distance square from a tower.

•  Wind car differ from wind turbines which are intended for electric power creation from wind power.  Wind - cars shouldn't work during a wind because their long thin blades aren't intended for processing of high wind force. 

• The noise created by Wind Machines and SIS fans (as they work generally at night) is a big problem for producers of crops near big and small settlements, and it should be considered at a choice of a method of protection against frosts.

Literature review

The review of literature showed that to active impact on atmospheric processes the huge attention is paid to questions recently that once again confirms relevance of a problem. 

Generally they concern the natural phenomena having one reason (existence of temperature inversion), - frosts, maybe fogs [1-20].  The range of scientific researches includes as fundamental works, for example, on problems of microphysical processes in the cloudy environment, and the practical works directed on development of concrete schemes, devices and ways of impact on frosts. 

Generally articles and patents are devoted to creation of initiation of vertical convection in a ground layer of the atmosphere leading to weakening of the detaining inversion layer or to formation of channels in it for air circulation. It allows "to air" the prizemny layer of the atmosphere closed by a fog. To the main directions of such influence, proceeding from level of equipment as of the present, it is necessary to carry: use of reagents and means of their delivery; electricity application. [41-47] ]

For example, in the patent [26] the way of impact on atmospheric educations by creation of vertical convective draft by means of ionization of air and a zone feeding this draft is offered. Such zone is created on the periphery of a formed zone of vertical convection also by means of air ionization.

In the patent [27] the way based on impact on atmospheric processes by means of sound waves and reagents засева is offered. Sound waves are generated at a vibration mode of burning of the channel solid propellant active elements which movement in the set direction and on the set trajectory is carried out at the expense of the jet force created by products of combustion, expiring on the one hand the channel. Besides, for strengthening of influence of sound waves use dispersion of reagents засева at resonant (for water drops) frequencies.

Other factor testifying to undesirability of use of some reagents, their toxicity negatively influencing ecology of environment is.

Electricity application belongs to the most perspective direction of impact on atmospheric processes from the point of view of ecology.

Ways in which basis introduction in atmospheric educations instead of reagents of koroniruyushchy wires with giving on them electric tension is necessary are known. As well as in case of use of the reagents, the essential lack of the specified technical solutions consists in the big expenses determined by an expense of fuel and energy resources for vehicles, providing delivery in atmospheric formations of koroniruyushchy wires, as served as a cause of failure from their realization.

Considering undoubted advantages of ways of impact on thermal inversion by means of electricity and for elimination of noted shortcoming, koroniruyushchy wires began to place directly with an earth surface. Namely in zones where continuous protection against undesirable manifestations of frosts (the areas occupied with sowing crops) is necessary.

Essence of the invention: over the koroniruyushchy wires executed in the form of electrowire grids, place the grounded conductor on which create the electric potential equal to local capacity of Earth. The conductor is executed in the form of an electrowire grid. During generation by grids electrically the loaded particles establish the wind direction then the grounded grid move in the vertical plane up to the height corresponding to the maximum potential difference between a layer of the atmosphere and a surface of Earth. [31] ]

Fundamental experimental works on application of stationary koroniruyushchy wires are carried out in the USA, and the received results are reflected in the published materials.

In the patent [28] it is offered to use the device, in which damp cold air is started (taken below an inversion layer), by means of a balloon rises up, heats up at the expense of solar energy. Then falls below an inversion layer and is issued. Big dry air bubbles are warmer than air, using energy of atmospheric water vapor, destabilize atmospheric layers of inversion, and allow the air being under it to rise up naturally.

In other way part of a surface of a land cover with a material, differing the thermal and/or radiation properties, for example, an asphalt-like material. The covering from such material will intensively heat up sunshine and to heat air that creates chimney effect: constantly existing convection current of air is fed at the expense of colder air involved in an ascending stream to the place of heated air rising up. This way is however inapplicable if the sun is closed by clouds or a fog. Besides, for obtaining steady (stable) draft it is necessary to cover the territory in some square miles that will demand a large number of a material.

The simplest and effective method of fight against temperature inversion - a turbulent (helicopter) way. Helicopter it is called because helicopters are used for hashing of warm higher layers of air with ground colder. Them use at protection of protection of gardens and vineyards against suddenly come frosts. The screw of the helicopter represents the mobile fan with the power plant. Using onboard indexes of temperature of external air, helicopters find zones of warm air and screws direct air streams on agricultural grounds. The helicopter way of fight against frosts has a number of advantages. First, it is highly mobile, depends on change of the direction and speed of a wind a little and allows to liquidate temperature fall on the big areas. Secondly, this way appears ecologically much purer, than smoke screens. It is known that traditional methods of fight against frosts – fumigating and smoke – lead to that a large number of aerosols is entered into air, a soot, a smoke and other harmful substances. [32,33] ]

However mass use of helicopters, of course, is an unacceptable method. Besides, the engine of the helicopter is rather strong pollutant of air.

The same principle is used at use of fans (Wind Machines). Axial fans with a diameter of driving wheels of 12-25 meters are actually applied. Air movement in them happens at an angle to a horizontal axis and during and at the same time for some time they make turn round a vertical axis. Thanks to it they can protect rather big area from frosts. [37] ]

The Ausvat Pty Ltd company uses the so-called SiS technology where axial fans too the big sizes are applied to pumping out of cold layers of air from the bottom layers of the atmosphere where on their place warmer layers preventing frosts arrive. [38-41] 

Main idea of the project

The main idea of the project consists in realization of a way of blocking (prevention) of formation of a warm inversion layer in a ground layer of the atmosphere over protected vineyards and gardens and by that to eliminate one of the main reasons for emergence of frosts. 

The solution of this problem is offered to be reached simple, but effective way with use of the unique installations [50], allowing to air (to mix air) considerable volumes of space over objects.

The physical principle consists in the following: 

Radiation frosts are formed as a result of cooling at night a spreading surface owing to terrestrial radiation or because of running off from slopes of heights in falls of cold air with a temperature below 0 °. Emergence of radiation frosts is promoted by lack of clouds at night, small humidity of air and windless weather.

Advective frosts result from invasion on this or that territory of cold air masses (the Arctic or continental polar masses).  In these cases of a freezing have steadier character and cover the considerable areas. 

The following conditions are necessary for formation of the radiation: 

•  Lack of overcast or existence of overcast of the top circle as the increase in overcast and fall of the basis lead to strengthening of counterradiation of the atmosphere and reduction of effective radiation of a terrestrial surface that doesn't promote its cooling; 

• Light breeze (1-2 m/s) and small turbulence which promotes air cooling from an active surface.

The problem of prevention of emergence of a fog can be successfully solved by airing of the bottom ground layer of the atmosphere.

After sunset at temperature fall at a surface of the earth installations which move warmer overlying air down where it mixes up with colder underlying layers join, possibility of fall of air temperature below 0 °C is excluded

Thus, there is a possibility of preservation of a standard type of the atmosphere for all night and morning time on rather big area, emergence of the inversion layer which is at the bottom of frosts, fogs, смогов and other natural phenomena isn't allowed.

Originality of work

The idea of supply of warm air in a ground layer of the atmosphere or removal from it cold air for reduction of influence of an inversion layer is well-known and is used long ago in world practice.  Such decision is applied on vineyards, in airfields for the purpose of fog dispersion, on pits to their airing etc.  However originality of our method consists in application for these purposes of special installations [50]. 

In these installations unique low-speed fans with a dimension of the driving wheel of 10-100 meters which allow to move considerable volumes of air (more than 10 000 m3/s) at the minimum power expenses (10-50 kW) are used. The processes happening during the work of such installations, are ecologically safe and very close to atmospheric processes.

Methodology

When performing work it is supposed to use the complex of methods which is including:  the analysis and synthesis of earlier executed researches on a problem;  laboratory and industrial experiments;  instrument and tool measurements;  mathematical modeling, trial tests of means. 

In each case on creation "Systems of protection of vineyards and gardens from frosts" the concrete model of installation, proceeding from features of geographical, topographical position of a vineyard or a garden has to be selected.

For an example technical characteristics of installations of various dimensions are given in table 1, but at the same power of 30 kW 

Table 1

Expected results

It is supposed to develop highly effective "System of protection of vineyards and gardens from frosts", including a wide tiporazmerny number of the installations differing on the power and productivity, for possibility of their use on various on topography, overall and other dimensions vineyards and gardens. It is thus supposed to consider the demands made to installations: their look, sizes, design, noise, etc.

Introduction of such system will significantly reduce losses of grapes and other crops from severe winters and frosts.

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