SU765604A1 - Device for automatic protecting of air heater from freezing - Google Patents

Description

relay 3 has a normally open contact 14 that is connected to the power supply circuit of winding 7, and a normally closed contact 4 is connected to the power supply circuit of winding 6.

By means of the automaton 15 with the power supply through the button 16 Stop and the button 17 Start, the magnetic starter 18 is connected, the contact button 17 of the Start button is blocked by the normally open contact 19, and the normally closed contact 20 by the intermediate relay 3 is connected to the power supply network. The main contacts 21, 22 and 23 of the magnetic actuator 18 connect the electrical supply network to the motor 24 of the fan 25. The actuator 8 is connected to the air temperature controller 26 in the room. The control voter 27 changes the mode of operation of the drive, 8, which can operate in automatic control mode and in manual mode. In manual mode, the actuator 8 is controlled by a key 28. To improve the accuracy of controlling the air temperature in the room, a step pulse interrupter 29 is included in the temperature regulator circuit 26. The device operates as follows. If the ventilation system is operating in automatic mode, the automat 15 and the magnetic starter 18 are turned on, the main contacts 21, 22 and 23 of the starter are closed, the normally open contact 19 is closed, the normally closed contact 20 is open, the fan 25 is turned on. In this case, the anti-freeze protection device is disabled. The actuator 8 by the regulator 9 is connected to the temperature controller 26, which controls the operation of the regulator. In order to increase the control accuracy, the actuator 8 is supplied via a stepped pulse interrupter 29. In the manual mode, the actuator 8 is controlled by the key 28 as follows: the control selector 27 is switched to the Manual control position and through the control key 28, the temperature controller 26 and the stepped pulse interrupter 29 electric current is fed to the actuator 8.

The shutdown of the ventilation system is accomplished with the Stop button 16, at this time the starter 18 turns off and opens its main contacts 21, 22 and 23, the normally open contact 19 and closes the normally closed contact 20, then the current to the motor 24 does not flow and the fan 25 stops, accordingly, the regulator 26 of temperature and the pulse chopper 29 are de-energized. The closed contact 20 turns off the heater unit's anti-freeze protection device. On the winding of the intermediate relay 3, the current flows through pin 2 of the sensor-relay 1, or through

pin 13 of the sensor-relay 12, pin 14 of the intermediate relay 3 is closed, and pin 4 is opened. Accordingly, a current flows to the winding 7 of the actuator 9, and the regulator 9 closes.

When the outdoor temperature is in the range (+3) - (+ 40) ° C, the sensor-relay 1 closes its contact 2 and opens it at temperatures below.

At temperatures above (+20) - (+ 30) ° C, the sensor-relay 12 closes its contact 13 and opens it if the temperature is below the specified value.

Thus, if before a heater

the air temperature is higher, the regulator 9 will always be closed, since the current through the contact 2 of the sensor-relay 1 will flow to relay 3 and, accordingly, through the closed contact 14 of the relay 3 to the winding 7 to close the drive 8. The regulator 9 will be in that position until those then until the outdoor temperature is above -1-30 ° C. If the air temperature falls below + 3 ° С, i.e. the threat of freezing will come

the heater, the sensor-relay 1 opens its contact 2, the relay 3 is de-energized, contact 4 is closed and contact 14 is opened. At that, the current through contact 20 of the magnetic starter 18 and contact 4 of the intermediate relay 3 will go to the winding 6 to open the drive 8, and the regulator 9 by step; j opens the coolant enters the heater 11. The flow rate of the coolant in this case will be maximum. Pin 2 of sensor-relay 1 will be

open until the outdoor temperature is higher.

As soon as the temperature of the return heat carrier exceeds the setpoint, the sensor-relay 12 closes its contact 13, the current flows to the relay 3, which opens the contact 4 and closes the contact 14. Then the current flows to the winding 7 to close the actuator 8 and accordingly the regulator 9 closes heat carrier access to the heater.

When the heater cools (to a temperature below + 3 ° C), the sensor-relay 12 will again open the regulator 9.

Thus, the heating of the heater will be carried out intermittently, i.e. discretely

when the heating periods will be determined by the outside air temperature and their frequency by the cooling rate of the heater, i.e. the economic expense of the heat carrier will be provided.

Claims (1)

Invention Formula  An automatic anti-freeze heater protection device containing a sensor-reliance of the temperature of the outside air, the contact of which is included in the supply circuit of the intermediate relay with a normally closed contact, installed in the relay unit connected to the power supply circuits of the windings of the regulator mounted on A return heat carrier pipe of the heater, characterized in that, in order to ensure an economical consumption of the coolant, the device further comprises a temperature sensor relay of inverse heat transfer fluid, the contact of which is included parallel to the contact sensor 46 relays temperature of external air, an intermediate relay has HopManikHo open contact is included in one of the windings prnvoda supply chain, and normally closed contact is incorporated in the power circuit other windings recently. Sources of information taken into account during the examination 1. USSR Author's Certificate No. 399688, cl. F 24 F P / OO, 1971. at I P 2S L V - (d I j phi &,} -but B F