SU735572A1 - Method of thermal distillation process control - Google Patents

Description

(54) METHOD OF MANAGING THE PROCESS OF THERMAL DESPINEMENT

FIELD OF THE INVENTION The invention relates to the control of NIN) multiple-effect evaporator down-pressure plants. It can. to be used for evaporation of seawater for drinking and pro- duction of lazy-goat water supply, for cleaning steam generators of TPPs and ABCj, for purifying polluted waters, as well as for deep evaporation of seawater for the purpose of extracting salt salts.

A known method of controlling the process of thermal desalination in a multi-unit desalination plant, carried out by varying the supply of heating steam by the temperature of the solution in the evaporator with a correction for the density and flow rate of the initial solution 1.

The closest in technical essence to the proposed is a method of controlling the desalination process, in which the impact of the heating pair is influenced by the difference in the measured pressure of the secondary steam and the maximum allowable pressure determined by the measured salt concentration of the initial evaporated solution 2,

However, in the known method, an increase in the productivity of the installation according to the DISTILLATE leads to an increase in the specific heat consumption.

The purpose of the present invention is to reduce the cost of a distillate by increasing the production capacity of the plant, according to the distillate.

To do this, measure the costs of heat,

10 sea water, electricity, multiply the measured values by weights and calculate the relative value of the obtained values to the measured installation capacity by

15 distillate that. By acting on the flow rate of heating steam, the ratio obtained is reduced so that the pressure of the secondary vapors in the separator of the first body does not exceed the allowable

20 values

The drawing shows a functional diagram that implements a method for controlling the process of thermal desalination in a multi-unit air installation.

The method is carried out as follows.

Claims (1)

The signals from the outputs of the flowmeter 1 n thermometer of resistance 2 are fed to the input of the device 3, which you use the q of heat supplied to the installation, according to the formula C-- o ush ochio .. o. I,. where q is the measured value of the heating steam consumption, t / h; tj, and are the measured and lasting temperatures of the thundering steam, C is the current and nominal pressure values of the heating steam, kgf / cm J is the nominal value of the enthalpy of heating steam kcal / kg, a, b, k, correction factors, taking into account the pressure, temperature and density of the heating steam. For saturated steam, P is defined as a known function of t. A signal proportional to the amount of heat applied to heating steam q from device 3, as well as signals from the marine iao flow meter 4. () supplied to the main capacitor, and the signal from the electrical ecology counters 5 spent on desalination (Oe) e to device b, in which the measured values are measured by weighting factors (k ,, Kj, Kj), equal to the prices of units of measured values. The sum of the products obtained and the constant value A are calculated taking into account the conventionally fixed costs of the multi-desalination plant. The output signal of device 6 is equal to QK / q + + KjQ5 + A. The output signal from device b enters the separating device 7, W Kdf 6pOM has been agreed to divide the magnitude of the signal Q by the amount of propitatable distillate signal flow into the device 7 s output of the 8th home decoder 8. C: ignored the cost of the distillate from the output of the device 7 iodine to the input of the automatic optimizer 9, which searches for the minimum determined in the device 7 of the cost by affecting the heat generator Schr, 15 A subsequent pilot control action on the valve valve: HoSch1 re | Shchyog 10 connected to the output of the optimizer 9 depends on the prohibiting: Signal of the logic device 11, the output signal of the logic device 11 f 5 is set by sending a signal from the output9 of the high-frequency conductometer 12 that serves for measuring the concentration of salts of the solution evaporated in the first housing 13 to the input of the nonlinear converter 14, performing non-linear conversion of a signal proportional to the concentration of salts of the evaporated solution I B signal proportional to the maximum permissible pressure of secondary vapors in the separator zone of the first housing 13, according to the known dependence of the sulphate barrier, Signal proportional to the actual secondary vapor pressure in the separator of the first housing 13 from the sensor 15. The input device 11, which determines the magnitude and sign of the difference between the maximum allowable and actual pressure of the secondary vapor. If this difference is positive, then the optimizer 9 gives a control action to the valve 10, otherwise the device 11 forbids the optimizer 9 to increase the steam flow. Thus, when the automatic optimizer 9 searches for the optimal cost value of the secondary vapor pressure in the separator of the first body will not exceed the allowable value. The invention The method of controlling the process of thermal desalination in a multi-unit desalination plant by acting on the flow rate of heating steam by the pressure of the secondary vapor in the separator of the first body, which distinguishes With | that, in order to reduce the cost of one ton of distillate. By increasing the productivity of the ijio installation, they measure the costs of heat, seawater, electricity, multiply the measured values by weights and extract the ratio of the sum of the values obtained to the measured performance of the distillate and by influencing the heating flow rate, the ratio obtained is reduced so that the pressure of secondary vapors in the separator of the first body does not exceed the permissible value, sources of information, etc. n tae into account poi examination 1, USSR Author's Certificate № 441940, cl. B 01 D 1/00, 1972. 2, USSR Author's Certificate of Application 2339456/26, Cl, C 02 B 1/06, 30.03,76.