SU1359603A1 - Method of controlling cryogenic unit modes of operation - Google Patents

Abstract

The invention makes it possible to reduce energy consumption at a variable compressor capacity, using expanders with brake stages, making part of the expanders in the form of turbines, and one - piston with intake and exhaust valves. For this purpose, sensors 31 and 32 t-ry and pressure sensors 39 and 40 measure t-ru and pressure at the inlets and outlets of all expanders. Their efficiency is determined and maintained at maximum values by affecting the brake stage of the turbines and measuring the cut-off angle of the intake and exhaust valves 22 of the piston expander 21. Measured by the sensor 42 i -py of the heat exchanger S installed in front of the de- struktro. m 21, and for this t-re corrects the xslow-productivity of the latter by acting on the brake with a stupid 6 yy ,. 2 Il. u Gg. I j I nA I & p SHZH D40 GTGLD / On Qm iTm I & Sch% III, i, ii F &JLL;; : ChstroyshVo se (by a subject / 1 / AMLi} G iLuuueK / iii. (KANAK) W || HAitH AND i I t I I I I Sh I i | ELV I I 1 Figure 1 O5 SL C «

Description

113

The invention relates to refrigeration engineering, in particular to methods for controlling cryogenic plants.

The purpose of the invention is the abbreviation ::. energy consumption at a variable compressor capacity, the use of expanders with brake stages, some of the expanders being made in the form of turbines, and one - piston with inlet and exhaust valves.

Fig. 1 schematically illustrates a system implementing the described control method; Fig. 2 shows a T-B diagram for determining the efficiency of the expanders.

The system contains an adjustable compressor with a thyristor unit 2, which changes the capacity of compressor 1, heat exchanger 3-8 through which turboexhaust flow 9 passes, main flow 10 and reverse flow 11, adjustable turbo expander L 12-14 and oil distribution valves 15-17 and sensors 18–20 rpm, respectively, piston expander 21 with intake and exhaust valves 22 and electromagnetic clutch brake 23, adjustable throttle 24, temperature sensors 25–3 installed at the inputs and backs of the expanders, 33–40 pressure sensors, micro computers 41 and t rmometr 42 mounted on tegshoob 8. Melnik level sensor 43 measures the urs, Shade 44 in the collection liquid gels gazg ol- der 45 is designed for collecting the helium gas.

T is the S-diagram of pressure and the values of the temperature that determine the source gas at the inlets and out, according to which the calculation,

5tJ 7-- j

those refrigerant sherathures at the inlet and outlet of the expander are consistent with the pressure of the refrigerant at the inlet and outlet of the expander; respectively, j enthalpy and input and output expander, respectively,

o

The enthalpy 1 during the isentropic process of expanding the refrigerant is determined by conducting from the point with the coordinate P of the isentropic to the front of the j1 of the j section of the

Bh

isobar P

VC /.

thirty

The system implementing the method of controlling a variable mode cryogenic plant operates as follows.

Compressor 1 compresses helium vapors, coming from the gas tank 45 and reverse flow 11, and directs the forward flow where the helium under pressure / pressure is distributed to two streams — the expander 9 and the main 10. Compressor capacity 1 set by the thyristor unit 2. The expander flow 9 passes through the heat exchanger 3 and expands in the turbine e-thunder 12. The temperature is measured. sensors 25 and 26 and pressure sensors 33 and 34 at the inlet and outlet according to the output of turboexpander 12, and using the values of these parameters, microcomputer 41 calculates the enthalpy by T-B-diagram, shown in Fig. 2, and determines the efficiency turboexpander 12, which is brought to its maximum value, for example, by the m-method of sequential approximation by acting on the braking stage, namely, the mass distribution of the turboexpander 12. Reception is carried: . Change the oil consumption through the oil distributor 15, determine ij, compare it with t determined in the previous step, burn the maximum value j, then

 this operation is repeated many times and is found, after which the effect on the oil dispenser 15 is stopped. In a similar way, they are calculated and given; To the maximum, the efficiency of the remaining turboexpanders 13 and 14 is affected by their distribution on the oil distributors 1bi I 7, respectively.

The main stream 10 passes through the headen exchangers and the new expander 21 is fed to the piston Q. The optimization of the operation of expander 2 is carried out by measuring the temperatures of the sensors 31 and 32 at the inlet and the output, as well as the powerings of the sensors 39 and 40, respectively, but calculates using the values of these parameters. T-S-diagram enthalpy, determines the efficiency of the piston expander 21, which ngH- is led to the maximum by the method of approximation by the action on the inlet and outlet clamps 22. The temperature is measured by sensor 42 of the last heat exchanger 8 in front of the piston expander 21, and the cooling capacity of the piston expander 21 is corrected by the value of this temperature. In addition, by the sensor 43 of the os level, the correction of the throttle flow is influenced by the throttle 24.

The capacity of the installation can be changed at the request of the consumer of liquid gels, while the consumer sets the specified compressor 1 performance by affecting the thyristor unit 2, and the microcomputer 41 calculates the performance of the installation from known dependencies and displays the operating parameters of the installation on the display. Sensor 18

20 maximum values by the impact on turbine brake stages and by changing the cut-off angle of the intake and exhaust valves of the piston expander, in addition, measure the temperature of

20 turns protected

turbine expanders from exceeding the fault of the exchanger installed before

of a high number of revolutions. The piston expander, and according to it the formula of the invention, recites the cooling capacity.

The method of controlling the modes of operation of the latter by influencing

cryogenic unit with compressor, brake stage.

adjustable expander, direct and reverse heat exchangers, choke and liquid collector

of refrigerant by raising the flow rate of the return flow after l ossel according to the level of liquid refrigerant in the collector, with the fact that, in order to reduce energy consumption at a variable compressor capacity, the use of expander with brake stages, the NRP-1 part of the expander in the form of turbines, and one - the piston with intake and

exhaust valves, additionally measure the temperature and pressure at the inlets and outlets of all expanders, determine their efficiencies and maintain them at maximum values by affecting the turbine brake stages and changing the cut-off angle of the inlet and outlet valves of the piston expander, in addition, heat up

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FIR.

Compiled by E.BiniorpaAOB

Editor L. Ogar

Tehred M. Khodanych

Order 6142/41, Circulation 476 Subscription

VNISh of the USSR State Committee for Inventions and Discoveries 113035, J ocKBa, Ж-35, Rau1isk nab. 4/5

Production and printing company, Uzhgorod, Projecto st., 4

Proof.P.Korol

Claims (1)

Claim A method for controlling the operating modes of a cryogenic installation with a compressor, adjustable expanders, direct and return heat exchangers, a throttle and a liquid refrigerant collector by influencing the return flow after the throttle according to the level of liquid refrigerant in the collector, which differs from the fact that, with. the purpose of reducing energy consumption with variable compressor performance, using expanders with brake stages, performing part of the expanders in the form of turbines, and one piston with inlet and outlet valves, additionally measure the temperature and pressure at the inlets and outlets of all expanders, determine their efficiency and support them at maximum values by acting on the brake stages of turbines and changing the cutoff angle of the inlet and outlet valves of the piston expander, in addition, The temperature of the heat exchanger installed in front of the piston expander is determined, and the cooling capacity of the latter is adjusted by it by acting on its brake stage.