SU979824A1 - Water cooling temperature control method - Google Patents

Description

The invention relates to shipboard power engineering, and specifically to methods for ensuring the uninterrupted supply of outboard cooling water to heat exchangers of power plant systems of an ice-sailing vessel.

A known method of controlling the temperature of the cooling water, according to which the temperature of the cooling water entering the heat exchanger is measured, forms the difference between the measured and set temperature and changes the flow of cooling water passed through the heat exchanger to the ice box in proportion to its value.

The known method does not provide high accuracy in maintaining the temperature of the water cooling the heat exchanger of the power plant in conditions of maneuvering the vessel in ice, when a significant increase in ice and snow in the ice box leads to a drop in water cooling temperature and a breakthrough of ice and snow masses to the heat exchanger, which in a number of cases causes clogging of its surfaces and, accordingly, a decrease or even cessation of water circulation. In these situations, the heat exchanger fails, causing an emergency condition of the power plant.

The aim of the invention is to improve the accuracy of regulation.

This goal is achieved by measuring the temperature of the water in the mixing chamber of the ice box, determining the rate of change and the sign

10 speeds, compare the found speed value with the setpoint and, if this value was exceeded, a given value and a positive speed sign reduce the supply of cooling water, 5 passed through the heat exchanger, to the ice box mixing chamber, and increase it with a negative sign.

The drawing shows a diagram of an apparatus for controlling the temperature of a water cooling system.

Claims (1)

The system contains an ice box 1, divided into a receiving chamber 2, a mixing chamber 3 and a separation chamber 4, a circulation pump 5, a heat exchanger 6, regulating dampers 7 and 8 with a servo drive, a regulator 9 of the cooling water temperature at the heat exchanger inlet, a sensor 10 temperatures, adders 11 and 12, block 13 for shaping the signal according to the speed change of water temperature, temperature sensor 14 and 1 mixing chamber 3. The temperature controller 9 processes the signal of the coolant outboard temperature sensor 10 in front of the heat exchanger b and sends command signals to the adders 11 and 12. The same signal gives the command signals to the signal generation unit 13 on the rate of change of water temperature, processing the signal from the water temperature sensor 14 camera mix The resulting signal of the adder 11 is fed to the servo drive of the regulating valve 7, which changes the water discharge overboard, and the signal of the adder 12 goes to the servo drive, adjusting the valve 8, which changes the water supply after the heat exchanger b to the mixing chamber 3. Water from the side enters the receiving chamber 2 of the Ice Box 1 further into the mixing chamber 3, where it mixes with the heated reagent after heat exchanger b, and into the separation chamber 4, from where it is received circulating, with pump 5, is pumped through the heat exchanger 6 and through the regulating valve 7 is partially discharged beyond the board and through the regulating valve 8 partially enters the mixing chamber. The method is implemented as follows. When sailing a vessel in clear water with a temperature exceeding the setpoint value of the temperature controller 9, the latter, after processing the sensor signal 10 from the meter, sends the control signal to the servo actuator of the regulating valve 7 through the adder 11 to open it completely, and through the adder 12 to the control signal for a complete closure of the regulating valve 8. The block 13 generates at the same time a zero signal due to the constant value of the temperature of the outboard water in the mixing chamber. In this case, the outboard cooling water, taken into the ice box 1, passes through the receiving chamber 2, the mixing chamber 3, the separation chamber 4, and circulating. With a stationary pump 5, which pumps it through a heat exchanger b, and then through a fully open control valve 7, it is thrown overboard. When the water temperature drops overboard the vessel to a value less than the value of the regulator 9 setting, the latter, receiving the corresponding signal from sensor 10, generates and transmits through adders 11 and 12 command signals to cover the regulating valve 7 and open the regulating valve B. В In these conditions, either the clear water or water with ice and snow enters the ice box and the recirculation channel through the regulating valve 8 receives water heated in a heat exchanger 6. If the rate of change in the amount of ice and from The pressure in the mixing chamber is small, then the output signal of unit 13 is zero and does not affect the control process. At the same time, the position of the shutters 7 and 8 depends only on the temperature of the water taken by the EEG board and the content of ice and snow in it. With a sharp change in the content of ice and snow in the seawater entering the mixing chamber 3, the temperature of the water in the latter and the signal of sensor 14 begin to noticeably change. Under these conditions, the absolute value of the signal in terms of the rate of change of the temperature of the water in the mixing chamber, developed in block 13, may exceed its setpoint value. At the same time, at the output of the unit, simultaneously with a change in the water temperature in the mixing chamber 3, signals are generated for a change in the supply of heated water into this chamber in an amount that allows reducing the rate of change in water temperature in the chamber to the dead zone of block 13, and in the case of a negative value the speed of measuring the water temperature in the mixing chamber 3 to the adder 11 will receive an additional signal to cover the valve 7, and to the adder 8 an additional signal to open the valve 12. In the case of a positive value awns additional signals are reversed. The remaining imbalance will gradually work out regulator 9. Thus, block 13 compensates for sharp fluctuations of ice and snow in received water due to an additional change in the supply of heated water at the same time as they occur, which allows controller 9 to maintain the temperature setpoint without noticeable overshoots and, most importantly, without cooling water in ice box. The use of the proposed method allows the heat exchangers of the power plants of icebreaking vessels to provide cooling outboard water in all operating modes of the vessel. Claims The method of controlling the temperature of cooling water in a ship system containing a heat exchanger and an ice box with a mixing chamber by changing the supply of cooling water passed through a heat exchanger to the ice box mixing chamber is proportional to the deviation of the actual value of the cooling water temperature at the inlet to the heat exchanger from the specified value that, in order to increase the accuracy, the temperature of the water in the ice box mixing chamber is measured, the rate of its change and the sign of the velocity are determined; The found speed value with a given value and when this value is exceeded with a given value and a positive speed sign reduces the supply of cooling water, the heat exchanger is placed in the mixing box of the ice box, and with a negative sign, increases. Sources of information taken into account during the examination 1. Alexander MA. Ways to increase reliability by cooling the steam turbine plant in ice flooding conditions. - Shipbuilding, 1973, 8, p. 28