SU1751626A1 - Method for starting two-stage turbocompressor refrigerating plant - Google Patents

Abstract

Usage: in the petrochemical industry. The invention: according to the start-up method, before evaporation of the liquid refrigerant, the evaporators are disconnected, which are reconnected after the working pressure in the condenser is reached. 1 silt

Description

The invention relates to refrigeration technology, as well as to turbo-compressor installations.

A known method of automatically starting a two-stage compression unit with a common drive motor and intermediate vessel, with a bypass valve on a second-stage compressor and a bypass valve on an intermediate vessel and a first-stage compressor by turning on the electric motor when both bypass valves open and unload the first and second compressor stages and the intermediate vessel and then closing them after the motor has reached the nominal speed.

The disadvantage of this method is that it does not allow the first and second stages of the compressor to be unloaded in the event of the start-up of the thermal installation due to the increased vapor density of the refrigerant in the suction into the compressor, which leads to an overload of the electric motor.

In addition, the bypassing of the freon vapors from the injection to the suction in the second stage of the compressor without their intermediate cooling is associated with the danger of a strong overheating of the freon.

The closest to the proposed method is the start-up of a two-stage refrigeration unit of a turbo-compression unit (DHTU) by draining the liquid refrigerant from the condenser-compressor azostat with the industrial vessel to the receiver, starting the turbocharger, increasing the pressure in the condenser to the operating one, supplying the liquid refrigerant to the industrial vessel.

The disadvantage of this method is low efficiency, starting at high pressure drops during suction and discharge in the low-temperature and high-temperature stages, due to the presence of liquid freon in the condenser and the industrial vessel at operating pressures, which leads to an overload of the compressor electric motor

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at start-up and significant loss of electric power, to a sharp increase in the leakage of freon vapors

The purpose of the invention is to increase efficiency

This goal is achieved by the fact that according to the method of launching a two-stage refrigeration unit of a turbo-compressor unit by draining a liquid refrigerant from a condenser-compressor aerostat with projectile into a receiver. starting the turbocharger, increasing the pressure in the condenser to a working one, and giving the liquid refrigerant to the industrial vessel, before discharging the liquid refrigerant, turn off the evaporators, which are reconnected after movement in the working pressure condenser

The drawing shows a diagram of a two-stage refrigeration turbo-compressor installation (DHTU), which implements the proposed method.

The installation contains a two-stage centrifugal compressor (PPM) consisting of a low-temperature stage (NTS) 1 and a high-temperature stage (VTS) 2, with rotary vanes of diffusers in each of the sections, driven through a multiplier 3 from a synchronous electric motor 4, one evaporator 5 of a high-temperature stage (VTS). two evaporators of the low-temperature stage NTS 6 and 7 of the industrial vessel 8, condenser 9, subcooler 10 liquid freon, receiver 11, anti-surge pipelines 12 and 13 connecting respectively the condenser with suction lines of the NTS and BTS pulp and paper mill, valves 14-25 with electric drive pipelines, check valves 26 and 27 on the discharge pipelines of the NTS Pulp and Paper Mill and the Pulp and Paper Mill, actuation and compaction valves 28 and 29 on the anti-surge piping of the NTS and VTS, regulating the valves 30,31 and 32 at the suction in the NTS Pulp and Paper Mill and the PTS and the inlet of liquid freon in the evaporator VTS automatic throttle valves 33 and 34

The installation that implements the proposed method for the start of DHTU, works as follows

When stopping the DHTU by closing the electrically driven valves 14,15,16,23 and 24 are divided into two circuits, the first circuit consisting of the VTS evaporator No. V and the NTS evaporators - V and VII, and the second circuit consisting of the NTS 5 and VTS 6 pulp and paper mill, condenser 9, subcooler 10 liquid freon, industrial vessel 8 and receiver 11 At the same time, the pressure of freon in the evaporators of the NTS and BTC

is set equal to the nominal R shutdown process; this pressure changes slightly due to good evaporation of the evaporators. All liquid freon from

the second circuit is drained into the receiver 11, while the freon vapors from the industrial vessel 8 are pumped out of the pulp mill and after condensation in the condenser 9 are also drained into the receiver 11. As a result, the vapor pressure of the freon into heat

the secondary circuit exchangers become equal to the suction pressure in the NTS. This starts up in the following order

In the second circuit open the valve

17-21 electrically operated control valves 30 and 31 on suction in the NTS of the pulp and paper mill and pulp and paper mill and anti-overflow valves 28 and 29 on the antispection pipelines connecting the capacitor with the suction lines of the NTS and BTS pulp and paper mills the diffuser vanes of the NTS and BTC pulp mills closed on position. open the regulating throttle valve 33. After the locking and regulating equipment is installed at the indicated position, the electric motor is started, and after the latter reaches the synchronous rotation, the valve 22 is opened in the pipeline connecting the receiver with the industrial vessel through the throttle

33 supply of freon from the receiver to the industrial vessel as the pressure drops in it

The operation of the second circuit DHTU continues until the working condensation pressure is established in the condenser when, by opening the valves 14-16,23 and 24 with electric drive, the first and second circuits are combined, simultaneously opening the regulating valve at the inlet of the liquid freon to the evaporator 32 and

control valve 34, providing the output of the plant to a mode that will operate in the usual two-stage compression cycle with full intermediate cooling

Claims (1)

Invention Formula The method of starting a two-stage refrigeration unit of a turbo-compressor unit by draining a liquid refrigerant from a condensing unit with industrial vessel to the receiver, starting the turbocharger, increasing the pressure in the condenser to the operating one, supplying the liquid refrigerant to the industrial vessel, characterized in that. in order to increase efficiency, before draining the liquid refrigerant, evaporators are disconnected, which are reconnected after the working pressure in the condenser has reached