SU826155A2 - Apparatus for regulating water temperature in water heating boller output - Google Patents

Description

(54) DEVICE FOR REGULATING WATER TEMPERATURE AT THE OUTLET OF A WATER BOILER

one

This invention relates to the control and regulation of hot water boilers.

According to the main author. St. No. 682735 discloses a device for controlling the temperature of the water at the outlet of a hot water boiler, comprising a temperature controller with two sensors, the first of which is installed at the outlet of the boiler, and a metering block for the vehicle’s lag, whereby the unit for lagging the boiler is taken as a hydraulic delay line, connected in parallel to the boiler, and the second sensor is installed at the output of this line. The delay line includes a parallel tube bundle, the hydraulic resistance of which is equal to the hydraulic resistance of the boiler 1.

This device provides a simplification of the regulation process, however, it cannot provide an increase in the regulation accuracy of the boiler operation in the prescribed mode with an accuracy of 0.15-0.2 ° C due to random disturbances caused by a change in the water flow rate at the boiler inlet, which leads to a decrease in quality regulation. The accuracy of the adjustment is in the range of 0.3-0.6 ° C.

The purpose of the invention is to improve the quality of regulation.

This goal is achieved by the fact that the device for regulating the water at the outlet of the boiler additionally contains a gas temperature sensor in the convective part of the boiler, and the temperature controller is provided with feedback to the memory unit to the second input of which the specified temperature sensor is connected.

FIG. 1 shows a diagram of the device; in fig. 2 - static characteristics of the boiler.

Claims (1)

A device for regulating the water at the inlet of the boiler 1 contains a temperature controller 2 with two sensors 3 and 4, the first of which is installed at the water outlet of the boiler 1, and the second at the outlet of the transport delay metering 5. A temperature sensor 6 installed in the cutting of the convective part of the boiler 1 is connected to the input to the memory block 7, which, in turn, is connected to the input and output of the temperature controller 2, and the output of the latter is connected to the flow control mechanism 8 air into the boiler. The unit 5 is taken into account of the transport delay of the boiler in the form of a hydraulic delay line and is connected parallel to the boiler. The delay line includes a bundle of pipes whose hydraulic resistance is equal to the hydraulic resistance of the boiler. Tyj (is the flue gas temperature in the convective part of the boiler; Atco is the difference between water temperatures at the outlet, е and at the boiler inlet; Gftoa is the air consumption in the boiler furnace at Gn, oa con-st; Gfnofv: fuel consumption in the boiler; a - the point of maximum difference in water temperature at the boiler inlet and outlet for a given optimal operation of the boiler, a is the temperature of the flue gases in the convective part of the boiler, corresponding to the optimum operation of the boiler. The device works as follows: water entering boiler 1 and water arriving at unit 5 for transport clearance reaches simultaneously the sensors 3 and 4 of the temperature, since the hydraulic resistance of the boiler 1 and the block 5 are equal.This reduces the random disturbances caused by the change in water flow through the boiler and the change in water temperature at the entrance to the boiler 1. Signals from sensors 3 and 4 arrive at The temperature controller 2 controls the supply of air or fuel to the boiler furnace, while the temperature controller 2 performs a step-by-step search for the maximum temperature difference between the water inlet and outlet from the boiler (point a, fig. 2) corresponding to the optimal combustion mode, affecting the executive mechanism for supplying air or fuel to the boiler furnace 1. If this effect causes the water temperature difference to rise, the system takes a step in the same direction until it reaches the optimum point, and if there is a decrease in temperature difference Ato), the system reverses. Having reached the optimal combustion mode, the controller 2 is turned off, and the memory unit 7 from the temperature controller 2 receives a command to memorize the flue gas temperature measured by the sensor 6 in the cutting of the convective part of the boiler (point b, fig. 2) corresponding to the optimum burning mode. This optimal mode is subsequently (in the established mode) monitored by the flue gas temperature sensor 6 and analyzed by memory block 1 When the flue gas temperature changes in memory block 7 from sensor 6, a signal is received about a change in the boiler operation. The memory unit 7 turns on the temperature controller 2 to search for the new optimal operation mode of the boiler 1. Upon reaching the new optimum mode, the temperature controller 2 is turned off again. In memory block 7, the flue gas temperature is recorded, which corresponds to the already new optimal mode, which later controls the operation of the boiler, etc. Therefore, in the steady state, the effect of random disturbances caused by changes in water flow through the boiler and by changing the water temperature at the boiler inlet. This leads to an increase in boiler efficiency, since in the steady-state mode, search losses caused by the listed disturbances, which do not affect the boiler burning mode, are ensured, which ensures accurate control of the boiler operation within 0.15-0,2 ° C. The sensitivity of the control system of the boiler temperature; flue gases (caused by a change in the combustion mode) with respect to sensitivity from; changes in the difference in water temperature at the inlet and outlet of the boiler A1 is higher. When the temperature difference changes by 0.2 ° C, the flue gas temperature changes by about 1 ° C. Therefore, the flue gas temperature is a more preferable parameter for controlling the operation mode of the boiler. The sign of the increment in the temperature of flue gases, in contrast to the increment of the difference in the temperature of the water Atto, gives additional information about the direction of change in the combustion mode on the boiler from the optimal one and indicates the direction the system searches for the optimal mode. When the flue gas temperature changes in the direction of increase (point B2, Fig. 2), the mode on the boiler changes towards the area of excess air and the system takes a step, reducing the air supply to the boiler. When decreasing (dot el, fig. 2) - to the side of the underburning region and the system takes a step. increasing the air supply to the boiler. This eliminates the false first step in the direction of the system searching for the optimal operation mode of the boiler. The invention The device for controlling the temperature of the water at the outlet of the boiler according to ed. St. No. 682735, characterized in that, in order to improve the quality of regulation, the device further comprises a gas temperature sensor in the convective part of the boiler, and the temperature controller is provided with feedback to the memory unit to the second input of which the specified temperature sensor is connected. Sources of information taken into account during the examination 1. USSR Author's Certificate No. 682735, cl. F 24 H 9/20, 1978. Leaving Guz Gas Air