SU1521380A1 - Method and apparatus for regulating oxygen in phytochamber - Google Patents

Abstract

The invention relates to agriculture and serves to regulate the oxygen in the phytochamber and measure the photosynthetic oxygen exchange of plants. The purpose of the invention is to improve the accuracy of oxygen regulation in the volume of the phyto chamber. The adjustable parameter is the generalized oxygen concentration in the sealed fitocamera 1, determined on the basis of the balance ratio for the 3-component gas mixture, based on current measured values of volume, pressure, temperature and concentration, provided that the specified amount of the neutral component of the regulated gas mixture — nitrogen. By the same data, the photosynthetic oxygen gas exchange of plants is also determined. The device contains temperature and pressure sensors 2 and 3 and a carbon dioxide gas analyzer 4. A flexible calibrated container 6, a volume change rate sensor 9 and a restriction device 8 are connected to the phytochamber 1. A computing device 11 is included in the device, the output of which is A regulator 12 and an actuator 5 are selectively connected, selectively affecting the oxygen balance in the phytacamera. 2 sec. and 1 z. p. f-ly 1 ill.

Description

 Pff

1 b f l

(L

sd y

00 00

)

of the current gas mixture, based on the data on the current measured values of volume, pressure, temperature and concentration, provided that the control of the neutral component of the regulated gas mixture, nitrogen, is maintained at a constant initial setting level. The photosynthetic oxygen gas exchange of plants is determined using the same data. The device contains sensors 2 and 3 hemperature and pressure and carbon dioxide

The invention relates to the field of agriculture, in particular to the regulation of the gas regime in vegetation climatic installations: cabinets, chambers, phytotrons.

The purpose of the invention is to increase the accuracy of oxygen regulation in the volume of the photocell.

The drawing shows a block diagram of a device for regulating oxygen in a phytochamber.

The method is carried out as follows.

The generalized oxygen concentration in the hermetic hermetic chamber is determined from the balance ratio for a three-component gas mixture based on current measurements of the volume change values: pressure, temperature and carbon dioxide concentration, while maintaining the control process at a constant, initially specified, level the amount of neutral component of the regulated gas mixture - nitrogen. Based on the same data, photosynthetic oxygen exchange is determined.

A device for implementing the method comprises a hermetic phyto chamber 1, equipped with sensors 2 and 3 of temperature and pressure, a carbon dioxide gas analyzer 4, an actuator 5 for controlled selective influence on the oxygen balance in phyto chamber 1 and a pressure compensator consisting of a flexible calibrated container 6 and a connecting gas line 7 with in-line tapering device 8. The pressure compensator is equipped with a sensor 9 for the rate of change of volume. The actuator 5 has a sensor 10 of the magnitude of the control action on the oxygen balance in the phytochamber. The device includes a computing device 11, the input of which is connected in parallel with sensors 2 and 3 of temperature, pressure, carbon dioxide analyzer 4, sensor

gas analyzer 4. To measure the value of the regulated volume of oxygen, a calibrated tank 6, a sensor 9 of the rate of change in volume and a restriction device 8 are connected to the phytocame 1. The device includes a computing device 11, to the output of which a regulator 12 and an actuator 5 selectively affecting the oxygen balance in the phytochamber. 2 sec. and 1 h. the item of f-ly, I ill.

9 of the rate of change of volume and the sensor 10 of the magnitude of the control action on the oxygen balance, and the output is connected to the oxygen controller 12, which, in turn, is connected to the actuator 5.

The device works as follows. The object of regulation is a three-component gas mixture consisting of nitrogen, a neutral component, the amount of which does not change during the adjustment process, as well as

0 carbon dioxide and oxygen. Moreover, the amount of carbon dioxide due to the photosynthetic activity of plants tends to decrease, while the amount of oxygen for the same reason, on the contrary, tends to increase. The constriction of the adjustable gas mixture is monitored using temperature and pressure sensors 2 and 3 and a carbon dioxide gas analyzer 4, which measures the volume concentration of carbon dioxide in a separate sample of the total gas sample. A flexible calibrated container 6, connected to the camera by means of a gas line 7, has substantially less rigid walls compared to the walls of the phyto chamber. Thanks to this, it is carried out

5 monitoring the change in the value of the regulated gas volume, for which the sensor 9 of the rate of change in volume is installed. At the same time, to reduce the fluctuation of the flow rate in the gas line 7, a restriction device 8 is installed. The total oxygen concentration is calculated from the balance ratio

Y (t) + X (t) -f Z (t) 100,

5 where -t is the current time;

Y-concentration of oxygen, vol.%;

Y is the concentration of carbon dioxide, vol.%,

Z is the concentration of nitrogen, vol.%.

In turn, from the condition of constant nitrogen content in the regulated volume, we get:

Z (t) Z (to)

P (t.) Ta) Y

T (t;). P (t) t

V (tJ + j v (t) dt

where -to is the start time of regulation;

P- pressure;

T is the temperature;

V- volume;

V is the rate of change of volume. As a result, the computing device 11, based on the measured current values of temperature, pressure, carbon dioxide concentration and volume change, taking into account the specified initial conditions, determines the current value of Y (t) using the following formula

Y (t) 100-X (t) -Z (t.).

V (to)

  i

V (to) + v (t) dt tt,

The calculated value of Y (t) is an adjustable parameter in the oxygen control channel, which is formed by the following successively included elements: a computing device 11, an oxygen regulator 12 and an actuation device 5. This channel acts selectively on the oxygen balance in the phytocalon, and there is a reverse communication in the form of a signal w (t), entering the computing device 11 from the sensor 10 of the magnitude of the control action on the oxygen balance in the phytochamber. As a result, parallel with the calculation of Y (t) using the computing device 1, the photosynthetic oxygen gas exchange of plants is calculated on the basis of the same data. The corresponding calculation formula is obtained as follows.

The last formula for Y (t) can be rewritten as

 (1) .Vo ((tVV. (T)

100 zlto). Yit .. Is.

100

T (tJ

PC

where V «(t) V (l.) + | v (t)

Kuschee value of regulated volume, reduced to standard values of temperature T, and pressure P.

The product Tin is the amount of oxygen present in

regulated volume. Derived by this quantity will be equal to

rY (t) -Vc (t)

1 122G

dt dX (t)

X (t) s

100

 -}

dt

100 dt

V (t).

ten

As a result, the calculation formula for the photosynthetic oxygen gas exchange of plants will be as follows:

"(" (,). BU) jsui ,, "(". ",",

where l7 (-t) is the generalized intensity of photosynthetic oxygen gas exchange, reduced to standard values of temperature Td and pressure FJ,;

w (-t) -controlling effect on the oxygen balance in the phytacamera. In the particular case, when P (to) P (t) const, T (to) T (t) const, X (t) const,

Xf-t)

w 0 and 1 the corresponding calculation formulas for Y (t) and U (t) will be

Y (t) 100 - X (t) - Z (to) X

thirty

.Y (t ..)

V (to) + j v-dt

35

U (t) - di

Consequently, control over the intensity of photosynthetic oxygen gas exchange of plants is carried out in the simplest way - by measuring the rate of change of the controlled gas volume.

Thus, the goal of the invention is achieved: an increase in the accuracy of oxygen regulation in the volume of the phyto chamber, as well as a concomitant increase in the measurement accuracy of the generalized photosynthetic oxygen gas exchange of plants.

Claims (3)

1. A method for regulating oxygen in a phytochamber, including measuring the volume concentration of carbon dioxide, temperature and pressure in a phytochamber while maintaining the concentration of the third neutral component nitrogen in the phytochamber and controlling the volume concentration of oxygen in the phytochamber, characterized in that increase the accuracy of regulation oxygen in the volume of the phyto chamber, the latter through a gas line with a restriction device communicates with the calibrated tank and measure the amount of change in the volume of the calibrated capacitance and the volume concentration of the neutral component, and the volume concentration of oxygen at each current time Y (t) is determined by the formula Y (t) 100 - X (t) - Z (t.) P (t ") - T (t)  P (t) -T (t,) X V (to) V (to) + J v (t) dt where Y is the volume concentration of oxygen; fc is the current time; to- start adjustment time; X is the volume concentration of carbon dioxide; Z is the volume concentration of the neutral component (nitrogen); Tbg is the current temperature value; P (- e) is the current pressure value; Vt is the initial value of the controlled volume at the initial values of temperature T (to) and pressure P (c5 (4) is the rate of volume change. 2. The method according to claim 1, characterized in that the photosynthetic oxygen gas exchange of plants is determined by the formula (t) N dVoU). dX (t) 100 dtdt v (t) (1 X Vc (t) + w (t), where 7 (4) generalized intensity of photosynthetic oxygen gas exchange, Pt Vo (t) V ((t) .dtj | b -Ti Pp five 0 five 0 five the current value of the regulated volume, reduced to standard values of temperature Te, and pressure P ,,; w (-t) -controlling effect on the oxygen balance in the phyto-chamber. 3. A device for regulating oxygen in a phyto chamber containing a hermetic phyto chamber, temperature sensors, pressure and a carbon dioxide gas analyzer, an actuator and a regulator connected to it, which is equipped with a flexible, calibrated capacity to increase the oxygen regulation in the phyto chamber. , a gas line, a restricting device, a sensor for the rate of change of the volume, a computing device, and a sensor for the magnitude of the control action on the oxygen balance, the outputs temperature and pressure ticks are connected to the inputs of the computing device, to the other inputs of which are connected the outputs of the carbon dioxide gas analyzer, the volume change rate sensor and the sensor value of the controlling influence on the oxygen balance, the input of which is connected to the sealed phytocamera and the output of the actuator , a flexible calibrated container is connected to a sealed phyto chamber by a gas line through a narrowing device, the input of a volume change velocity sensor is connected to a flexible calibrated container, wherein the calculation unit output is connected to the input of the regulator.