SU1702944A2 - Apparatus for automatic controlling of temperature conditions in a green house - Google Patents

Abstract

The invention relates to agriculture, in particular to the technique of providing a microclimate in structures of closed and protected soil, primarily in greenhouses, and is an improvement of the invention according to the author. St. No. 1405729. The purpose of the Invention is to improve the accuracy of optimization of the temperature regime by accounting. plant age is achieved by multiplying the signal of the timer 13 of the plant age by a constant value S / 2a in the additional multiplication unit 20 and by summing the result with the luminous indices in the addition unit 21. 1 il.

Description

The invention relates to agriculture, in particular to a technique for providing a microclimate in structures of enclosed and protected soil, primarily in greenhouses, and is an improvement of the invention according to ed. St. No. 1405729,

The purpose of the invention is to increase the accuracy of temperature control by taking into account the age of the grown plants.

The drawing shows a functional diagram of the device.

A device for automatically controlling the temperature in the greenhouse contains a sensor ί of air temperature in the greenhouse 2, a setter 3. a comparing element 4, a conversion-amplifying device 5. a switch 6, a clock generator 7 and an actuator 8 controlling a regulating body, for example, a valve (not shown), in the heating system, as well as the computing unit 9, and whose input signals are sent from the track sensors: air humidity 10, wind speed 11. lightened 12 and timer 13, counting the age of the plant I. ''

The computing block represents co. battle algebraic device consisting of individual elements; performing elementary algebraic operations. The composition of the computing unit 9 includes blocks. ’14-17 calculations of the coefficient of heat loss, blocks 18-20 multiplication, block 21 addition and block 22 subtraction. 35

The device operates as follows; zom. ·., 7 ;,> .. ·. ···. · The outdoor humidity sensor 10 measures the humidity <p, converts it into an electrical signal and enters it into the calculation unit 14 K _v = D φ. The wind speed sensor 11 measures the wind speed V, converts it into an electrical signal and enters it into the block 15 for calculating the coefficient Kv =. . = φ \ /.

In addition, the signals from the humidity sensor 10, and the wind speed sensor 11. dissolved in calculating unit 16 and the product and multiplying by a constant coefficient K -values F. _{ζ mp,} K _o, F φ \ / are supplied to unit 17 - addition determining factor 'K teploloter which is then multiplied at ⁷ v' L1 block T 18 by a constant value of '2aCu

The sensor 12 will measure the illumination E in heat ^: 2 at a certain distance from the surface of the earth And convert it into an electrical signal, which in block 19 of blocks 18 and 21 is supplied to the subtraction block 22. The output of this block is the output of the entire computing unit as a whole. The output signal from the computing unit is fed to the input of the setter 3, the signal from. which, proportional to the optimum temperature, is supplied to the comparison device 4. Another signal to the comparison device is supplied from the sensor 1 of the internal temperature. The mismatch signal received at the output of the comparator 4 is converted in accordance with the necessary control law and amplified by the device 5. then through the switch 6 it enters the actuator 8, which sets in motion a regulatory body that changes the coolant supply. The switch 6 is designed to turn on and off the actuator 8, and the generator 7 clock pulses for the formation of time intervals.

Thus, during the pause between pulses, the actuator must move, and during the pulse, the previous result is reset, • the computing unit is turned on, the optimal temperature is calculated and stored for the next pause. The pause time must also be such that any of the effects can be considered constant over a given interval.

• When the device is operating, the following dependence is realized: 15

h ..

AE - Ц _у АУ - Цт ΔΟ, where Цу - unit price of a product; AE is an economic criterion; Ct - the price of a unit of thermal energy; AU - part of the crop, classified as discrete. time span and equal to

<- ’* ·. · 'U - the size of the crop of Vegetables; g-period of growing vegetables;

Δτ is the time interval during which the magnitude of the perturbation does not change; ,.

'V g1702944

AQ - the energy spent on heating the greenhouse for a period of time Ar.

The dependence of this indicator on the temperature of the air in the greenhouse is extreme.

The device allows you to determine the temperature. at which there is an extremum, an economic indicator, and to maintain this temperature within specified limits.

Since the measurements of AU and AQ are not carried out directly, but with the help of a ma: thematic model, the coefficients * of which remain constant, this condition for the extremum of the function is found from the condition that the derivative of the exponent with respect to temperature tB be equal to zero _; air in the greenhouse, which / 'after mathematical calculations leads to the form /, 1Е ₊ 2а · -. · _2аЦ (N + Dp + pV + FpV) “ ^For Sr _p

2a + _b_)

2a> 'where N is a constant value;

Gy is the age of the plant.

This formula includes two terms, the first of which is proportional to the heat loss coefficient, enclosed in brackets, and the second characterizes the temperature correction depending on the measurement of illumination and the age of the plant.

Claims (1)

Claim Device for automatically controlling the temperature in the greenhouse, according to ed. St. No. 1405729, characterized in that, in order to improve the accuracy of temperature control by taking into account the age of the grown plants, it is additionally equipped with a timer for plant age and a unit for multiplying the plant age by a constant value, the output of which is associated with an additional input of the first addition unit, while the output of the timer the age of the plants is connected to the unit multiplying the age of the plants by a constant value. . / »• V '·> ; · - / 7 * 5. · '- ;. ..:. · ^: . · • “Λ- ' .: ·· * * · * = - · . - - · - X ._,. • - • <g. _h 7. 'V * - * L: '··' · ' ⁵ ·''·''' . h - '; . . . '.. 7.7' '·. ·. · . ... . - .. ·  '7 . * ^: ·· “·; * * - ./Λ? ' _ - 7 - '7 • 7 ... -_- = • -. · -. 7 .7 Z · .. · - •  '· · - .: - · •. -V-. <· * . ' A·. ⁷ * . ·· - · '  A * F - - ' - ’·. · 7 w · / ' ^: . ^: -. 7 .. '- -; · / 7 ·· .... • - * . , - / · '. -:> ·· : · J ,. ///. '- · ^: ./7- \ · * ·. ·, - , -Γ •. ··. H g • shopping mall ·. '‘7' • g '· -. g , '7  : -J - - -  . Λίί ?. th / . · 7 ’to„ ~ 7 , 7-. .g /. i G -ίί. · - · 4 · ·· · * w / l ’.