JPH11132675A - Control method for condenser - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control the condensate temperature at a constant level regardless of fluctuation in the quantity of inlet steam by detecting the outlet condensate temperature and the outlet condensate pressure, regulating the cooling air volume of a fan and then controlling the outlet pressure such that the degree of supercooling will be constant. SOLUTION: The steam inlet pipe of a steam header 1 is provided with a steam flowmeter 6 and the condensate outlet pipe of a condensate header 3 is provided with a temperature regulator 7 and a pressure regulator 8. The temperature regulator 7 regulates the cooling air volume of a fan and the pressure regulator 8 cantrols a condensate outlet regulation valve 4. Outlet temperature of a condenser can be controlled at a substantially constant level by regulating the outlet pressure and the r.p.m of the fan when the steam flow rate at the inlet of the condenser fluctuates intensely.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling the condensing temperature of a high-pressure steam condenser in a refuse incinerator, a refuse melting furnace or the like having a power generation facility.

[0002]

2. Description of the Related Art Recent waste incinerators, waste melting furnaces, etc.
A power generation facility is provided to recover heat, and the heat recovery facility is provided with a high-pressure steam condenser.

FIG. 3 shows an outline of a high-pressure condenser (steam condenser) described in Japanese Patent Publication No. 6-78868.

[0004] A blower 5 for sending cooling air to the high-pressure condenser main body 2, a water level controller 13 for controlling the condensate outlet control valve 4 to adjust the water level in the machine, and a pressure controller for controlling the blower 5 to adjust the in-machine pressure. Consists of eight. In this high-pressure steam condenser, the internal pressure is controlled by adjusting the amount of cooling air from the blower 5, and the degree of supercooling is controlled by adjusting the condensate outlet control valve 4. With this method, even if the amount of steam flowing into the high-pressure condenser fluctuates, the pressure inside the machine can be kept constant, and at the same time, the degree of supercooling of the condensate can be kept above a certain level. There is a feature that can be.

[0005]

The high-pressure condenser detects the water level and controls the degree of supercooling by level control. However, in a refuse incinerator or a refuse melting furnace, the amount of steam generated fluctuates greatly. In the case of control, it is difficult to accurately detect the level because the pressure loss of the steam passing through the machine fluctuates due to a change in the inlet steam amount. In a small-scale condenser or a recent steam condenser having improved heat transfer efficiency, the head difference between the steam header and the condensate header is 500 to 1.
Since it is as small as about 000 mm, fluctuations in the internal pressure due to changes in the amount of steam at the inlet become large disturbances in level detection and cannot be controlled well. Therefore, it is difficult to control the degree of supercooling by level control in the condenser temperature control of a condenser having a small head difference between the steam header of a small condenser or the like and the condenser header.

Accordingly, the present invention provides a control method for a high-pressure steam condenser for controlling the condensate temperature to be constant without performing level detection and irrespective of a change in the amount of steam at the inlet of the high-pressure steam condenser. Is what you do.

[0007]

The control method of the high-pressure steam condenser according to the present invention detects the outlet temperature of the condensate of the high-pressure steam condenser, adjusts the amount of cooling air from the blower with a temperature controller, and controls the temperature. And the pressure of the high-pressure steam condenser outlet is detected, and the pressure is controlled so that the degree of supercooling of the condenser becomes constant.

[0008] A line graph (horizontal axis: steam volume at the inlet of the condenser, vertical axis: the amount of steam at the inlet of the high-pressure steam condenser, taking into account the changes in the heat transfer efficiency and the internal pressure, which are characteristics of the high-pressure steam condenser.
The condenser outlet pressure setting (S condenser outlet pressure setting)
V value). At this time, a moving average process is performed on the SV value in consideration of a time delay of the pressure fluctuation in the condenser.

[0009]

FIG. 1 is a diagram for explaining a control method according to the present invention. Steam from the refuse incinerator and the refuse melting furnace is supplied from the steam header 1 of the high-pressure steam condenser to the high-pressure steam condenser main body 2, condensed, and discharged from the condensing header 3. A condensate outlet control valve 4 is provided in a condensate outlet pipe of the condensate header 3. A blower 5 is disposed in the high-pressure steam condenser body 2 to send cooling air.

The steam inlet pipe of the steam header 1 is provided with a steam flow meter 6 for measuring the amount of steam, and the condensate outlet pipe of the condensate header 3 is provided with a temperature controller 7 and a pressure controller 8. The temperature controller 7 controls the amount of cooling air from the blower, and the pressure controller 8 controls the condensate outlet control valve 4.

Next, a control method will be described.

The condenser outlet temperature is detected, and the cooling air flow from the blower 5 is adjusted by changing the rotation speed and the blade angle of the blower 5 by the temperature controller 7 so that the condenser outlet temperature becomes the set temperature. Control.

However, there is a time delay in the detected condensate temperature. Regarding the response delay in the temperature detection, a line function (horizontal axis: condenser inlet vapor amount, vertical axis) corresponding to the amount of steam by the steam flow meter 6 is used. (Axis: condenser outlet temperature setting) 9, the temperature compensation amount is calculated by the calculator 10, and added to the operation amount of the temperature controller 7 to perform feedforward control.

Further, the pressure is detected by detecting the outlet pressure of the steam condenser and adjusting the condensate outlet control valve 4 by the pressure controller 8. Here, movement is performed through the steam flow meter 6 and a line function (horizontal axis: condenser inlet steam amount, vertical axis: condenser outlet pressure setting) 11 in consideration of changes in heat transfer efficiency and in-machine pressure of the steam condenser. The averaging process is performed by the arithmetic unit 12 and the set value (SV
Value).

FIG. 2 is a graph showing the results of an operation test performed by the control method of the present invention.

It can be seen that the condenser outlet temperature is controlled to be substantially constant by adjusting the outlet pressure and the number of revolutions of the blower, despite the fact that the condenser inlet steam flow rate fluctuates drastically.

[0017]

According to the present invention, the condenser outlet pressure is controlled so that the condenser efficiency is constant without performing the level control.
Stable condensate temperature control can be realized and controllability can be improved.

[0018] Regardless of a change in the amount of steam at the inlet of the steam condenser, the condenser can be controlled at a pressure at which the degree of supercooling is constant, and the controllability of temperature control is improved.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining a control method of the present invention.

FIG. 2 is a graph showing a result of an operation test performed by the control method of the present invention.

FIG. 3 is a diagram showing an outline of a conventional high-voltage capacitor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Steam header 2 High pressure steam condenser main body 3 Condenser header 4 Condenser outlet control valve 5 Blower 6 Steam flow meter 7 Temperature controller 8 Pressure controller 9 Line function 10 Temperature compensation amount calculator 11 Line function 12 Moving average Processing unit 13 Water level controller

Claims (2)

[Claims] When performing the condensate temperature constant control and the condenser internal pressure constant control, feedforward control is performed in which an inflow steam amount which is a main disturbance is detected and a compensation amount calculated from the detected amount is added. In the control method of the high-pressure steam condenser, the outlet pressure of the high-pressure steam condenser is detected, and this pressure is controlled so that the degree of supercooling of the condenser is constant. Water control method. 2. The feed-forward control according to claim 1, wherein a time delay of pressure fluctuation and a response delay of temperature detection in the high-pressure steam condenser are controlled by a steam flow rate at the inlet of the high-pressure steam condenser. Control method of high-pressure steam condenser.