SU1722302A1 - Method for controlling microclimate in farm buildings - Google Patents

Abstract

The invention relates to agricultural production and can be used in greenhouses, poultry houses and other agricultural premises equipped with a calorific heating system and supply and exhaust ventilation. The purpose of the invention is to reduce energy costs and improve the reliability of the microclimate maintenance system and its sustainability. The invention relates to agricultural production, and can be used in greenhouses, poultry houses and other agricultural premises equipped with a radiator heating system and supply and exhaust ventilation . The purpose of the invention is to reduce energy costs and increase the reliability of the microclimate maintenance system and the stability of its operation. Figure 1 shows a flowchart that implements the proposed method; at work. This is achieved in order to maintain the microclimate in room 1 for agricultural purposes, containing a supply heating and ventilation unit 2 and exhaust ventilation unit 8, measure the air temperature te in the room and compare it with the set temperature t.d. t - t.3 0, then maintain the flow of the exhaust unit 8 at the level of the sanitary rate of air exchange and smoothly reduce the flow of hot water through the heater 3. At the same time, if overheating is not eliminated, then fix the moment of valve section 5 on th whose water, and then gradually increase the supply of an exhaust installation. And under the condition t - Тз 0 fixes the flow of exhaust unit 8 at the level of sanitary standards and then smoothly increases the flow of hot water through the heater 3. The setpoint of the setpoint 15 of the regulator 13 of the axial flow fans 8 is set greater than the setpoint of the regulator 13 heating unit 2 on the half-sum of the ranges of the adjustment characteristics of both the regulators 12 and 13. 2 Il. Fig. 2 is a timing diagram providing algorithms for the interaction of the regulators. The system for maintaining the temperature in room 1 includes a heating and ventilation unit 2 containing a heater 3, a centrifugal fan 4, a valve 5 with electric drive 6 and a heating battery 7. The exhaust ventilation unit consists of exhaust axial fans 8 equipped with an electric drive 9. The automatic control device contains sensors 10 and 11 of the air temperature in the room, proportional to the regus of air.

Description

Lorers 12 and 13, the outputs of which are connected respectively to the motors of the fans 8 and the control valve 5. The dials 14 and 15 of the electronic regulators are mounted on the external panel of the control panel 16, and the dials 17 and 18 of the values of the control characteristics inside the temperature controllers . Ventilation shafts 19 serve to supply fresh outside air.

The system of maintaining an optimal microclimate, which implements the proposed method, works as follows.

The unit 2 supplies the supply air to room 1, the fans 8 emit warm internal air from the room, which contributes to the flow of cold outside air (the method is used during the cold season) through shafts 19 and fan 4 due to the dilution of air (with the valve 5 turned off coolant). The supply of fans 8 depends on the magnitude of the imbalance between the required temperature t3 and the current temperature of the hot water in the room. If the temperature in the room exceeds the set point txey, then the fan flow smoothly changes from minimum to maximum; when the temperature in the room decreases to the border of the regulation zone, the supply of the fan 8 decreases to a minimum (sanitary standard, usually 0.2-0.3 of the nominal supply of the fan). Similarly, the operation of valve 5 of the coolant occurs: when the temperature in the room decreases, the trey valve opens slightly and when the temperature rises more than the trey valve closes up to a minimum (usually 0.05-0.1 of the nominal flow rate, which is caused by the need to protect the heater from freezing).

Suppose a room temperature varies from tgi to tgs. At the tgi point, the valve 5 on hot water (KGB) opens slightly, and the capacity of the axial exhaust fans (DOM) is fixed at the sanitary standard.

At point tg2, the low pressure valve is in the middle position, and the 0V feed is the same; at the tgs point, the KGB is covered to a minimum, the CID remains unchanged; In the 94 KGB covers up to a minimum, the STB gradually grows; At the tgs point, the KGB is covered to a minimum, the CID is increased to a maximum.

The diagram (see Fig. 2) shows that the separation of the setpoints of the tasks of the KGB and TWA controllers automatically blocks the increase in performance (supply) of exhaust fans 8 until the moment when the hot

water (taking into account trouble-free operation of the heater) in the heating system 2 without introducing additional electrical) (or mechanical, etc.) connections between the controllers

12 and 13. This increases the reliability of the microclimate control system. In addition, lowering the setpoint of the dial for the KGB. relative to the unit for supplying exhaust system ensures the stabilization of the process of maintaining the microclimate. To illustrate, consider the process of operating the regulators at the tgs point. With the proposed control method at this point, the valve 5 on hot water is closed and the supply of the exhaust unit is minimal. If the txey and trey settings are swapped, i.e. trey txey, then at the hdz point the control system goes to a different one: the SIL controller increases the flow of cold, and the KGB controller increases the heat supply, which

leads to irrational energy consumption to maintain the microclimate and increase the oscillations of the control system as a whole, i.e. to reduce the quality of the regulatory process. The choice of the magnitude of the reduction of charter

ki tgv value

DXB + Ore

due to

with the following circumstances: if the settings of the TCU and trey are combined, then there is uncertainty in the operation of the regulators, if trey txsy, then there is a different work of the regulators (in the zone between the settings), if

Dxb + ogv

trs decrease more than. for example, the room is overcooled as KGV starts

D

GW

open only with trey + -4f-, therefore

The arrangement of the control zones of both controllers 12 and 13 is the most rational one, since the joint of the cooTBeTCTByef ranges minimizes the supply of 0V and HGV, which is equivalent to the physical interlock of the controllers (meaning electrical or mechanical

5 connection between them).

Using the proposed method of maintaining a microclimate helps to reduce energy consumption by 15-20% during the cold season.

0

Claims (1)

The method of maintaining the microclimate in agricultural premises, which consists in measuring the current value of the air temperature in the room and comparing it with the target, while raising the temperature to the predetermined value is done by increasing the supply of hot water through the heating and air heater at fixed minimum capacity of the exhaust ventilation system, and lowering the temperature to a predetermined value - an increase in the performance of the exhaust ventilation Fitting for a fixed minimum flow of hot water through the heating air heater unit, characterized in that, in order to reduce energy costs and increasing the reliability of the system and maintain the microclimate stability of its operation, I / / fi / J, 7 Editor T. Gor chev FIG. 2 Compiled by B. Kuzmich Tehred M. Morgenthal An increase in the supply of hot water through the heating unit or the capacity of the exhaust ventilation unit begins with unequal set temperatures of the air in the room, and the setpoint value of the capacity control unit of the exhaust ventilation unit is set greater than the setpoint of the hot water supply controller heating calorific installation on the half-sum of the ranges of adjustment characteristics of both regulators. Proofreader T. Malets