RU2608065C2 - Method of determining and evaluating thermal conditions in zones of heating and keeping of young animals - Google Patents

Abstract

FIELD: agriculture.

SUBSTANCE: invention relates to agriculture, namely to livestock sector, and can be used to assess efficiency of using specific types of sources of infrared heaters. Method of determining and evaluating thermal conditions in zones of heating and content of young animals involves measuring of radiation intensity E_meas. [W/m²], generated by radiation heaters. Measurement is performed at least in two or more points within heated area of specified specific norms of process parameters for animals of specific type and age. Wherein taking into account normal component of radiation intensity vector E_meas. to area of heating. By results of measuring of radiation intensity distribution E_meas. is determined in heating zone. Required calculated radiation intensity E_calc. [W/m²] is determined by formula E_calc(Q_r/F_an-Cϕb_m-n(τ_an-t_r))/ε, where Q_r is explicit heat release by animal [W], C is powered coefficient of radiation (4.65 W/m²K⁴), ϕ is coefficient of illumination of elementary animal surface on fencing room structures (rad), b_m-n=0.81+0.01τ_av is correction temperature coefficient of [°C], τ_av=0.5(τ_an+t_r) [°C], τ_an is average temperature of animal surface [°C], t_r is average temperature of room fencing [°C], F_an is animal surface [m²]. Values of apparent heat generation Q_r of specific type and age (weight) of animal, surface temperature τ_an are taken from homeothermal or thermoneutral temperature zone, and coefficient b_m-p and radiation temperature of room t_r by standards of technological design for specific method of growing animals and climatic parameters. Calculated radiation intensity E_calc.l is defined for values of critical temperature t_cr.l and apparent heat generation Q_r(t_cr.l) at t_cr.l. Calculated radiation intensity E_calc.l is defined for values of lower neutral temperature t_n.l and apparent heat generation Q_r(t_n.l) at t_n.l. Calculated radiation intensity E_calc.u is defined for values of upper neutral temperature t_n.u. and apparent heat generation Q_r(t_n.u) at t_n.u. calculated radiation intensity E_calc.u is determined for value of upper critical temperature t_cr.u and apparent heat generation Q_r(t_cr.u) at t_cr.u. Values of radiation intensity E_meas obtained by measurement are compared with calculated required parameters of radiation intensity, wherein ratio E_calc.tcr.l≤E_meas.min≤E_meas.max≤E_calc.tcr.u, where E_meas.min is minimum value of measured radiation intensity E_meas on heated area, E_meas.max is maximum value of measured radiation intensity E_meas on heated area, favorable thermal conditions are established for livestock management, ratio E_calc.tn.l≤E_meas.min≤E_meas.max≤E_calc.tnu establishes optimally comfortable temperature conditions for livestock management, at ratios E_meas.min≤E_calc.tcr.l<E_meas.max≤E_calc.tcr.u, E_meas.min≤E_calc.tcr.l≤E_calc.tcr.u≤E_meas.max, E_calc.tcr.l≤E_meas.min≤E_calc.tcr.u≤E_meas.ma set relatively favorable temperature conditions for livestock management.

EFFECT: invention allows to provide required temperature conditions and permissible degree of non-uniformity of heating of young animals in area of keeping.

1 cl, 1 dwg, 1 ex, 2 tbl

Description

The invention relates to agriculture, in particular to livestock, and can find application in the creation of new means of heating, the development of algorithms and operating modes of control systems to create thermal comfort when heating animals, for example, calves, piglets, etc., as well as evaluating the effectiveness use of various types of heaters.

To determine the thermal state of animals, a method is known that establishes comfort conditions / Ya.A. Kungs, A.G. Lapitsky et al .; under the general. Ed. N.V. Tsuglenka. - Krasnoyarsk: Publishing house of Krasnodar State Agrarian University, 2008., Rastimeshin S.A. Local heating of young animals (theory and technical means), - M .: Agropromizdat, 1991). The first condition of comfort determines the area of combinations of the temperature of the internal air t _in and the radiation temperature of the room t _r , at which the animal, being in the recreation area, does not experience either overheating or hypothermia. The second condition for comfort determines the permissible temperatures of heated and chilled surfaces in close proximity to animals. The second comfort condition for describing the thermal state of animals is not defined or is formulated by the following sentence: the apparent heat transfer from all surface areas should be as uniform as possible (Heating of rural residential and livestock buildings with infrared sources. / Ya.A. Kungs, A.G. Lapitsky, etc. .; under the general editorship of N.V. Tsuglenka. - Krasnoyarsk: Publishing House of KrasGAU, 2008, Rastimeshin S.A. Local heating of young animals (theory and technical means), - M .: Agropromizdat, 1991).

The disadvantage of this method and the determination of thermal conditions in the zones of heating and keeping young animals is that it does not allow to determine the permissible degree of unevenness of the heat flow from heated and cooled surfaces located in the immediate vicinity of animals.

The task of the invention is to provide the required temperature conditions and permissible uneven heating of young animals in the detention area.

As a result of the use of the present invention, it is possible to determine conditions for a comfortable thermal state of animals with changing climatic parameters of the environment, age-related changes, requirements for the developed technical means for creating thermal zones with permissible uneven heating, as well as evaluating already known technical systems.

The above technical result is achieved by the fact that the proposed method for determining and evaluating thermal conditions in the zones of heating and keeping young animals includes measuring the radiation intensity E _ISM. [W / m ² ] created by radiation heaters, at least at two or more points within the heated area defined by specific norms of technological parameters for a specific type and age of animals, and take into account the normal component of the radiation intensity vector E _IS to the heating area, according to the measurement results determine the distribution of radiation intensity E _ISM. in the heating zone, while the required calculated radiation intensity E _calc. [W / m ² ], determined by the formula

_Calc E = (Q _YaV / F _w -Sφb _m-p (τ _w -t _r)) / ε,

where Q _JAV - the apparent heat of the animal [W],

C is the reduced emissivity (4.65 W / m ² K ⁴ ),

ϕ is the coefficient of irradiation of the elementary surface of the animal on the building envelope (rad),

b _m-p = 0.81 + 0.01τ _cf - correction temperature coefficient [° С],

τ _cf = 0.5 (τ _W + t _r ) [° C],

τ _W - the average surface temperature of the animal [° C],

t _r is the average temperature of the enclosure [° C],

F _W - the surface of the animal [m ² ],

moreover, the values of the apparent heat release Q _{Jav of a} particular type and age (weight) of the animal, the surface temperature τ _W are taken from the region of the homothermal or thermoneutral temperature zone, and the coefficient b _mp and the radiation temperature of the room t _r according to the technological design standards for a specific method of keeping animals and climatic parameters, the calculated radiation intensity E _rasch.kr.n values determined for the lower critical temperature and t _kr.n apparent heat release Q _YaV (t _kr.n) at t _kr.n, pa countable radiation intensity E _rasch.n.n determined to lower the neutral temperature t _NN apparent heat release values and _YaV Q (t _NN) at t _NN, the calculated radiation intensity E _rasch.n.v determined values for the upper neutral temperature t _nv and explicit heat release Q _JAV (t _NV ) at t _NV , calculated radiation intensity E _calc. value determined for the upper critical temperature t and apparent heat release _{kr.v YaV} Q (t _kr.v) at t _kr.v obtained measurement values of the radiation intensity E _rev, is compared with the calculated desired parameters of the radiation intensity, the ratio E _{rasch.tkr. n} ≤E _measurement min _≤E measurement.max _≤E calculation _tcr

wherein E _izm.min - minimum value of measured radiation intensity E _edited in the heated area,

E _izm.max - the maximum value of the measured radiation intensity E _edited in the heated area,

establishes a favorable thermal environment for keeping animals, the ratio of E _calc. tnn _≤E meas. _min ≤E _meas. max _≤E calc. _tnv sets the optimum comfortable temperature for keeping animals, with the ratios E _meas. min _≤E calc. _tcr <E _{meas.max ≤E} calculation _tcrv , E _meas. Min _≤E calculation _tcrn ≤E _{calculation tcrv} ≤E _meas.max , E _calculation tcrn _≤E meas. _Min ≤E _calc. tcr in _≤E meas. _m establish a relatively favorable temperature environment for keeping animals.

For a specific age and type of animal determine the permissible boundaries of changes in climatic environmental factors. Any warm-blooded organism at a certain temperature of the environment is in full temperature equilibrium, while the chemical processes in the tissues of the body ensure its vital activity, and additional energy is not spent on maintaining a normal body temperature. When environmental conditions change, the thermal balance of the body is disturbed, and the animal reacts with an increase or decrease in the rate of oxidative processes that generate heat (Panteleev P.A. Bioenergetics of small mammals. M: Nauka, 1983; V.M. Yurkov. Microclimate of livestock farms and complexes. M: Rosselkhozizdat, 1985), while the body temperature of the animal within the lower critical temperature t _cr.n and the upper critical temperature t _cr.v (the zone of homeothermy) is kept constant as a result of chemical oh thermoregulation. Within the boundaries of the thermoneutral zone, metabolism and heat production are carried out in minimal sizes, in this range animals give the highest gains (gains). The homeothermic zone U _g includes a thermoneutral region U _n , analytically this is expressed by t _{so called} ≤U _n ≤t _tv ∈ t _cr.n ≤U _g ≤t _cr.v , where t _n.n , t _{n. c} - the lower and upper values of the temperature boundary of the thermoneutral zone, t _cr.n , t _cr.v - the lower and upper critical temperature of the homeothermal zone.

In the homoothermal region U _{g, there} is a range of values of heat production Q _{g of} the animal organism, part of which is spent on maintaining homeostasis of the internal environment and heat exchange with the environment, the main component of which is the apparent heat loss Q _Jav , and include energy loss by convection, radiation and conduction. For the particular species and age (weight) of the animal introduces the concept of average specific heat with q = Q _ud body surface _YaV / F _w, whereas the thermal state of the animal will correspond zone temperature parameters U _r provided _YaV Q (t _kr.n) / F _w> Q _YaV / F _w> Q _YaV (t _kr.v) / F _w, i.e. the body will develop normally and adapt to external conditions, if the average specific heat transfer q _beats does not go beyond the specified limits, this corresponds to the concept of the first comfort condition. The main requirement when designing a microclimate system in livestock buildings is to create such thermal conditions in the animal habitat that will provide optimal thermal comfort in the recreation and animal welfare areas, this corresponds to the main exchange in the thermoneutral region t _n.n ≤U _n ≤t _{n. c} . In real conditions, heated and cooled surfaces, in particular cold floors, on which animals, various heaters of radiant, conductive type, etc., or a combination thereof, exert a thermal effect on the animal’s body. The determining value in this case is the heat transfer intensity q _i = dQ _i / dF _i on the most disadvantaged and sensitive part of the animal surface dF _i , which is influenced by heated or cold surfaces in the habitat of young animals. Heat balance must be such that for every elementary area, of the surface of the animal, the value of the intensity of heat transfer q _i does not exceed the limit values of average specific heat at the boundaries of the zone U _g.

In accordance with the above provisions determine the conditions of thermal comfort:

- such a general temperature situation in the animal zone will be relatively favorable that corresponds to the homeothermal temperature _range t _cr.n ≤U _g ≤t _cr.v , all the apparent heat is given _away , the animal’s body does not experience overheating or hypothermia, and the average specific heat transfer Q _JAV / F _W does not exceed the limit values of the average heat transfer at the boundaries of the region U _g

_YaV Q (t _kr.n) / F _w> Q _YaV / F _w> Q _YaV (t _kr.v) / F _w. ,

_YaV where Q (t _{kr.n) YaV} and Q (t _kr.v) - obvious heat animal at a lower critical temperature and t _kr.n upper critical temperature t _kr.v gomoyotermalnoy region [W], F _w - the surface of the animal [ m ² ]

- such a general temperature situation in the zone of animals, corresponding to the homeothermal temperature _range t _cr.n ≤U _g ≤t _cr.v , in which all apparent heat is given off, the animal’s body does not experience overheating or supercooling, and at the same time the specific heat transfer rate, will be favorable q _i = dQ _i / dF _i from different parts of the animal’s body should not exceed the limiting average values of the specific heat transfer at the boundaries of the homothermal zone U _g

q _i <Q _YaV (t _kr.n) / F _w and q _i> Q _YaV (t _kr.v) / F _w,

analytical expression of favorable thermal comfort

_YaV {Q (t _kr.n) / F _w> Q _YaV (U _z) / F _w> Q _YaV (t _kr.v) / F _w} ∧ {Q _YaV (t _kr.n) / F _w> q _i> Q _YaV (t _kr.v) / F _w};

- comfortable to such a general temperature conditions in animals finding the area corresponding to the area thermoneutral temperature t _{N NN} ≤U ≤t _NV at which heat is given to all apparent without experiencing overheating or overcooling and wherein the average specific heat transfer

Q _JAV / F _W does not exceed the limit values of the average heat transfer at the boundaries of the thermoneutral region U _n

_YaV Q (t _NN) / F _w> Q _YaV / F _w> Q _YaV (t _N.V.) / F _w. ,

_YaV where Q (t _{NN) YaV} and Q (t _N.V.) - obvious heat animal at lower temperature t _NN and upper temperature t _N.V. thermoneutral zone [W],

and (∧) in this case, the specific heat transfer intensity q _i = dQ _i / dF _i from different parts of the animal’s body should not exceed the limiting average values of the specific heat transfer at the boundaries of the region U _g , the analytical expression of thermal comfort has the form:

_YaV {Q (t _NN) / F _w> Q _YaV (U _n) / F _w> Q _YaV (t _N.V.) / F _w} ∧ {Q _YaV (t _kr.n) / F _w> q _i> Q _YaV (t _kr.v) / F _w};

- optimally comfortable will be such a general temperature situation in the zone where animals are located, corresponding to the region of thermoneutral temperatures U _n , at which all apparent heat is released without experiencing overheating or overcooling and the average specific heat transfer Q _jav / F _w does not exceed the limit values of average heat transfer by the boundaries of the thermoneutral region U _n

_YaV Q (t _NN) / F _w> Q _YaV (U _n) / F _w> Q _YaV (t _N.V.) / F _w. ,

and the specific heat transfer intensity q _i = dQ _i / dF _i from different parts of the animal’s body does not exceed the limiting average values of the specific heat transfer at the boundaries of the region U _n , the analytical expression of the optimal thermal comfort has the form

_YaV {Q (t _NN) / F _w> Q _YaV (U _n) / F _w> Q _YaV (t _N.V.) / F _w)} ∧ {(Q _YaV (t _NN) / F _w > q _i > Q _jav (t _n.v ) / F _g )}.

When exposed to radiant heaters in the heating (resting) zone, the second comfort condition should limit the heat exchange rate of the animal. The radiant heating system should ensure radiation balance in such a way that any elementary area on the surface of the animal on the most disadvantageous part of the body located to the radiation, gives out radiation to the surrounding surfaces, depending on the age and type of the animal, thermal energy within the limits determined by a favorable, comfortable and optimally comfortable temperature the situation in the heating zone.

The equation of radiant heat transfer for an elementary site on the surface of an animal has the form (Bogoslovsky V.N. Construction Thermophysics. - M.: Higher School, 1982)

q _i = Cφb _m-p (τ _w -t _r) -εE,

where C is the reduced emissivity (4.65 W / m ² K ⁴ ); ϕ is the coefficient of irradiation of the elementary surface of the animal on the building envelope (rad); b _n-m = 0.81 + 0.01τ _cp - temperature correction coefficient, τ _cp = 0.5 (τ _w + t _r); t _r is the average temperature of the enclosure; ε is the radiation absorption coefficient; E is the vector of energy irradiation from the emitter or heated surfaces and normally directed to the considered elementary area (W / m ² ), τ _W is the surface temperature of the animal (° C).

Exposure limits:

for the homeothermal zone -

_Rasch.kr.n E = (Cφb _m-p (τ _w (t _kr.n) -t _r) -Q _YaV (t _kr.n) / F _w) / ε,

_Raschkr.v E = (Cφb _m-p (τ _w (t _kr.v) -t _r) -Q _YaV (t _kr.v) / F _w) / ε,

where τ _W (t _red ) and τ _W (t _red ) are the values of the surface temperature of the animal at a temperature of t _red and t _red , Q _YaV (t _{kr.n) YaV} and Q (t _kr.v) - obvious heat animal at a lower critical temperature and t _kr.n upper critical temperature t _kr.v gomoyotermalnoy region [W]

for the thermoneutral zone -

_Rasch.n.n E = (Cφb _m-p (τ _w (t _NN) -t _r) -Q _YaV (t _NN) / F _w) / ε,

_Rasch.n.v E = (Cφb _m-p (τ _w (t _N.V.) -t _r) -Q _YaV (t _N.V.) / F _w) / ε,

where τ _w (t _NN) and τ _w (t _N.V.) - values of the surface temperature of the animal at the temperature t and t _{NN N.V.} thermoneutral zone, Q _YaV (t _{NN) YaV} and Q (t _nv ) - the apparent heat of the animal at the lower boundary of the temperature t _n.n and the upper boundary of the temperature t _{n in the} thermoneutral zone [W],

In FIG. 1. shows the results of measurements of the distribution of the values of irradiation E _meas. [W / m ² ] from sources of infrared heating LEO-250 and IKZK on a heated surface. The abscissa axis shows the distance from the central axis of the irradiator suspension, the ordinate axis shows the irradiation values. The horizontal lines indicate the calculated values of the radiation intensity E _calc. corresponding to the zones of the goyothermal U _r ⊂ E _{calc. cr} ... E _{calc. cr.} and thermoneutral U _n ⊂ E _{calculation n} ... E _{calculation n.} for calves. Values of E _{meas .} enclosed within the boundaries of E ... E _{raschtkr.n raschtkr.v.} and E _calc . _n ... E _calc. , determine the portion of the heated surface where the radiators create conditions for a favorable, comfortable and optimally comfortable temperature environment.

Examples (of the method):

- for a young piglet weighing g _f = 1 kg, F _f = 0.092 (g _f ) ^2/3 = 0.092 m ² ; surface temperature τ _w = 29.0 + 0.22t _in; thermoneutral zone - t _н.н = 28 ° C≤t _in ≤t _н.в = 30 ° C; homoyothermal zone - t _cr.n = 26 ° C≤t _in ≤t _cr.v = 33 ° C; explicit heat release depending on the temperature of the medium Q _jav (t _in ) = k _q q, here k _q = -0.0357t _at +1.357 (Ministry of Agriculture of the Russian Federation. Moscow, 2009); q = 5.9 W; climatic parameters of the environment - the radiation temperature of the room t _r = 18 ° C.

- for a calf weighing g _f = 40 kg, F _f = 0.104 (g _f ) ^2/3 = 1.2 m ² ; surface temperature τ _w = 24.5 + 0.43t _in; thermoneutral zone - t _н.н = 18 ° C≤t _в ≤t _н.в = 20 ° C; homoyothermal zone - t _cr.n = 15 ° C≤t _in ≤t _cr.v = 25 ° C; Explicit heat depending on the environmental temperature _YaV Q (t _kr.n = 15 ° C) = 59.1 watts, Q _YaV (t _NN = 18 ° C) = 52.2 watts, Q _YaV (t _N.V. = 20 ° C ) = 47.9 watts, Q _YaV (t _kr.v = 25 ° C) = 37.2 watts, climatic environmental conditions - radiation room temperature t _r = 10 ° C.

The calculation results are summarized in table 1 for piglets and table. 2 for calves.

Claims (14)

A method for determining and evaluating thermal conditions in the heating and keeping areas of young animals, including measuring the radiation intensity E _meas. [W / m ² ] created by radiation heaters, at least at two or more points within the heated area defined by specific norms of technological parameters for a specific species and age of animals, and take into account the normal component of the radiation intensity vector E _IS to the heating area, according to the measurement results determine the distribution of radiation intensity E _ISM. in the heating zone, while the required calculated radiation intensity E _calc. [W / m ² ] is determined by the formula E _calculation (Q _JAV / F _W -Cϕb _m-n (τ _W -t _r )) / ε, where Q _JAV - the apparent heat of the animal [W], C is the reduced emissivity (4.65 W / m ² K ⁴ ), ϕ is the coefficient of irradiation of the elementary surface of the animal on the building envelope (rad), b _m-n = 0.81 + 0.01τ _cp - correction temperature coefficient [° С], τ _cf = 0.5 (τ _W + t _r ) [° C], τ _W - the average surface temperature of the animal [° C], t _r is the average temperature of the enclosure [° C], F _W - the surface of the animal [m ² ], moreover, the values of the apparent heat release Q _{Jav of a} particular type and age (weight) of the animal, the surface temperature τ _W are taken from the region of the homothermal or thermoneutral temperature zone, and the value of the coefficient b _m-n and the radiation temperature of the room t _r according to the technological design standards for a specific method of keeping animals and climatic parameter, characterized in that the radiation intensity E calculated _rasch.kr.n determined for the lower critical temperature values t and apparent heat release _{kr.n YaV} Q (t _kr.n) when t _kr.n, the calculated radiation intensity E _rasch.n.n determined to lower the neutral temperature values t and apparent heat release _{NN YaV} Q (t _NN) at t _NN, the calculated radiation intensity E _{rasch.n. in} determine for the values of the upper neutral temperature t _NV and explicit heat release Q _JAV (t _NV ) at t _NV , calculated radiation intensity E _calc. value determined for the upper critical temperature t and apparent heat release _{kr.v YaV} Q (t _kr.v) at t _kr.v obtained measurement values of the radiation intensity E _rev compared with the calculated parameters required radiation intensity, wherein the ratio E _rasch.tkr.n ≤E _measurement min _≤E measurement.max _≤E calculation _tcr wherein E _izm.min - minimum value of measured radiation intensity E _edited in the heated area, E _izm.max - the maximum value of the measured radiation intensity E _edited in the heated area, establishes a favorable thermal environment for keeping animals, the ratio of E _calc. tnn _≤E meas. _min ≤E _meas. max _≤E calc. _tnv sets the optimum comfortable temperature for keeping animals, with the ratios E _meas. min _≤E calc. _tcr <E _{meas.max ≤E} calculation _tcrv , E _meas. Min _≤E calculation _tcrn ≤E _{calculation tcrv} ≤E _meas.max , E _calculation tcrn _≤E meas. _Min ≤E _calc. tcr in _≤E meas. _m establish a relatively favorable temperature environment for keeping animals.

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