SU1380675A1 - Method of controlling heat supply system of hothouse - Google Patents

Abstract

The invention relates to the field of control and regulation of heat supply processes in greenhouses and warehouses for storing vegetables and fruits. The purpose of the invention is to reduce the uneven temperature fields in the greenhouse. The air temperature is measured around the perimeter of the greenhouses at the exit of each section 1. At the same time, the number of the controlled section is recorded. The mean value of the temperature in the greenhouse room and the deviation of the temperature at the outlet of each of the sections from the calculated mean value along the greenhouse perimeter are calculated. The number of abnormal sections of the greenhouse is determined with values of temperature deviations greater than the allowable one, changed in one direction from the given value. Regulate the flow of coolant into the common collector 12, when the found number of anomalous sections is more than the allowable, and the connection of the heaters 3 separate sections 1 with a deviation of the measured temperature value from the average greenhouse, greater than the allowable value, is made if nai (L

Description

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1380675

The given number of anomalous sections is less than 1 ge permissible. The operation of adjusting the flow of coolant into the common collector 12 and the inclusion of heaters 3 separate sections 1 can be performed automatically or by the operator as recommended at the output of blocks 9 and 16. It is advisable to carry out the analysis of the correlation function of air temperature 1-2 times per shift . on average after 5 h, 2 Il.

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The invention relates to the field of control and regulation of heat supply processes in greenhouses and storage rooms for storing vegetables and fruits.

The aim of the invention is to reduce the irregularity of temperature fields in the greenhouse.

Figure 1 is a diagram explaining how to regulate the system; figure 2 - chart.

A device for implementing the method for controlling the heat supply of a greenhouse contains sections 1 of the greenhouse, in which sensors 2 of air temperature and heaters 3 of individual heat supply are placed. The outputs of the temperature sensors 2 are connected to the inputs of the sampling unit 4, to which the identifier 5 of the section number 1 is also connected.

The output of the sampling unit 4 is connected to the input of the unit 6 for calculating the average temperature, the output of which is connected to the input of the blocks 7 and 8 for estimating the magnitude of the temperature deviation. Unit 7 is connected with one output to one input of a correction output control unit 9, the second input of which receives a signal from the sensor 1a 10 of the threshold value of the coolant supply regulator 11 to the collector 12. A signal is supplied to the third input of the correction output distribution unit 9 from the output of block 13 comparing the signal of the adder 14 to the number of anomalous sections with the signal of the setpoint 15 of the permissible number of anomalous sections. One input of the second unit 16 for issuing a corrective action on the heaters of 3 separate sections 1 of the greenhouse is connected via unit 8 for estimating the magnitude of the temperature deviation

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3 with the output of the sampling unit 4, and the second input with the setting unit 17 of the heater connection threshold 3 3 separate sections 1. The input of the 14 number of anomalous sections is connected with the output of the sampling unit 4, and the output of the unit 9 through the heat supply regulator - with the executive common reservoir mechanism 18.

In the greenhouse (Fig, 1) it is necessary to maintain the desired air temperature. In sections 1 of the greenhouse, temperature sensors 2 are installed, which monitor the temperature of the air in the sections around the perimeter of the greenhouse. To maintain the temperature in the greenhouse, the flow rate of the coolant is controlled by means of the controller 11 and the actuator 18 installed on the coolant supply manifold 12. The connection of heaters 3 is necessary for temperature correction in the anomalous sections.

The adjustment method is implemented as follows.

Initially, using temperature sensors 2, the air temperature in the installation zones of the heaters 3 is changed, in sections 1. Information about the air temperature of all sections of the greenhouse through the sampling unit 4 is fed to unit 6, through which. the temperature value averaged over the sections of the greenhouse is calculated, and in block 7 of the estimation of the magnitude of the deviation. With the help of block 14, the number of sections of the warmth is calculated for which -. air temperature is out: permissible according to the regulations, taking into account only deviations of one sign, i.e. deviation to the big or the smaller side. With the help of the setting device 15 set the permissible number of anomalous sections of the greenhouse with the deviation of one sign.

Then, using block 13, the actually calculated number of anomalous sections is compared with the number specified by block 15. When the actual number of anomalous sections specified by block 15 is exceeded, a control signal is generated to adjust the flow of coolant to the common collector 12. Thereafter, the dosage flow Q coolant in the common manifold 12 is changed in proportion to the deviation

UQ A, (0i -0, a).

where uQ is the change in the flow rate of the heat bodies to the common collector; b; - actual average temperature in the greenhouse;

6 - ,, dd is the set value of the room temperature; And, - proportionality coefficient.

In this case, the issuance of a corrective action from block 9 occurs only if the correction value exceeds the threshold value set by the setting device 10, and if the enabling signal from block 13 is present.

If at least one of the specified conditions is not met, then the feed correction is not performed, but the heaters are connected by connecting 3 individual sections. For this purpose, information about the current value of the temperature CO of all sections is fed to the deviation value estimator 8. In this block, the output temperatures of each of the greenhouse sections are compared with the average value calculated by block 6. Then, using block 16, the calculated actual deviation is compared with the threshold acceptable value set by the setting unit 17. After this, the heaters of 3 separate sections are connected, to implement the algorithm:

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the temperature and the current temperature of the j-th section; A -) is a communication link for the connection between the connection of a cable and a chorifer with temperature deviation.

The need for counting and checking the number of sections at which the temperature value has gone beyond the time limit is explained in Fig.2. In this case, a large error in the mean value introduced only one value, which significantly differs from the tolerance. Adjustment of the coolant supply in the common collector 12 (if adjusted according to the average value) would have caused most of the hot-HHii temperatures to be beyond the allowable limits. The method eliminates the possibility of such an error. In this case, the sections will be adjusted, since the number of anomalous sections does not exceed the permissible value.

The operation of adjusting the flow of coolant to the collector 12 and the inclusion of heaters 3 separate sections 1 can be automatically or by the operator as recommended by the units 9 and 16, as shown by the analysis of the correlation function of air temperature, the way is expediently implemented by the operator 1 -2 times per shift (i.e. on average after 5 hours).

The proposed control method is implemented on standard elements, for example, TLC temperature sensors and АСКР type А701-03 installations or КСМ-4 bridges.

The proposed method, in comparison with the known method, makes it possible to reduce the irregularity of heat moles in heated rooms, which in turn will reduce the loss of vegetables.

Claims (1)

Invention Formula The method of regulating the heat supply systems of greenhouses, mainly multisectional, equipped with individual section heaters, by measuring the air temperature in the greenhouse followed (the correct temperature for the heat carrier is measured depending on the difference in temperature (;; and so that, in order to reduce the uneven temperature fields in the greenhouse, the air temperature is measured around the perimeter of the greenhouses at the output of each of the sections; emoy sec- tion, then dissolved vgchisl average value of the room temperature greenhouses and deflection of the outlet temperature of each section by calculating the average value of the perimeter of the greenhouse, then determining the number of abnormal sections greenhouses with a value otklone9 QL dtt 6 tp ml neither the temperature greater than the allowable one-sided change from the specified value and regulate the flow of heat transfer medium into the common collector when the found number of anomalous sections is greater than the allowable one, and the connection of the heaters of individual sections with a deviation of the measured temperature value from the average greenhouse, greater than the allowable value t, if the found number of abnormal sections of the greenhouse is less than the allowable, 4 Fug.Z t