KR100905120B1 - Ebergy saving system utilizing waste heat of heating tank in hot rolling mill - Google Patents

Abstract

The present invention is to minimize the water quality defects generated during the regeneration and supply of the pure water used to extend the life of the skid pipe which is a slab transfer device of the hot-rolled heating furnace, in particular to recover the waste heat of the hot-rolled heating furnace hot water using the same The present invention relates to a power reduction device using waste heat in a hot rolled furnace configured to control and maintain a temperature of an associated heating tank in a heating manner.

In the present invention, a furnace circulating water heat exchanger (50) capable of recovering waste heat from the furnace, and a furnace circulating circuit for increasing heat exchange efficiency in the furnace circulating water heat exchanger (50) and controlling primary skid pipe temperature and flow rate Shut off the hot water supply to inlet and shut off the water control valve 110, the heating furnace waste heat recovery control valve 111 to control the flow rate and temperature of the oil line circulation hot water, and the oil line circulation hot water to the heating tank 1. At the time of abnormality of the valve | bulb 95, the valve for controlling the heating tank temperature 93 which can always maintain the temperature of the heating tank 1 to a target value, and the hot water supply shutoff valve 95 and the valve for controlling the heating tank hot water 93 And a manual valve (96) capable of blocking circulation water during repair, a shutoff valve return blocking valve (94) for returning the heat exchanged oil line circulating hot water back to the return line and preventing backflow to the heating tank (1), and return Oil shut off valve (94) Manual valve 97 for blocking the circulating water, hot water heater 130 for heating the heating tank, thermometer 32 for detecting the temperature of the heating tank 1, control panel 90 and the field heating tank Provided is a power reduction device using waste heat from a hot-rolled heating furnace characterized by a configuration including an operator graphic panel 91 for monitoring and managing the temperature of (1).

Description

Power saving device using waste heat in hot rolled furnace {EBERGY SAVING SYSTEM UTILIZING WASTE HEAT OF HEATING TANK IN HOT ROLLING MILL}

1 is a schematic view of a pure water regeneration apparatus according to the present invention;

2 is a schematic diagram of a heating tank temperature control installed in the pure water regeneration device;

3 is a schematic view of the waste water recovery apparatus for circulating hot water of the hot rolling furnace;

4 is a schematic diagram of a hot water line for supplying hot water recovered from waste heat to hot rolling;

5 is a general configuration diagram of an apparatus according to the present invention;

6 is a heating tank control loop and algorithm block diagram in the apparatus of the present invention;

7 is a flowchart of a heating tank control program in the apparatus of the present invention.

Explanation of symbols on the main parts of the drawings

1: heating tank 2: caustic soda tank

3: hydrochloric acid tank 4: caustic soda neutralization tank

5: hydrochloric acid neutralization tank 6: filter tank

7: Resin Ion Tower 8: Pure Storage Tank

10: pump for hot water supply 11: oil line circulation pump

12: furnace circulating water cooling pump 13: hot rolling mill circulation pump

14: expansion tank level transmitter 15: steam thermometer                 

16: Factory circulating water flow transmitter 17: Factory circulating water pressure transmitter

20: cutoff valve for water supply of the filter tank 21: cutoff valve for water supply of the mixed phase ion tower

22: blocking valve for pure water supply tank 23: blocking valve for caustic soda supply

24: blocking valve for hydrochloric acid supply 25: blocking valve for neutralizing hydrochloric acid

26: blocking side for caustic soda neutralization 27: blocking side for supplying mixed-phase ion tower caustic soda

28: Blocking valve for supplying hydrochloric acid in a mixed-phase ion tower 29: Blocking valve for switching the circulation water in a heating furnace

30: heater power supply panel 31: heater control panel

32: thermometer for controlling the heating tank 33: heater

40: hot rolling furnace body 50: heating furnace circulating water heat exchanger

60: furnace circulating water cooling tower 70: expansion tank

80: steam heat exchanger 90: heating control panel

91: monitoring graphics panel 92: communication cable

93: valve for heating tank hot water control 94: return shutoff valve

95: hot water supply shutoff valve 96: manual valve for hot water supply

97: manual valve for return 98: bypass manual valve for hot water supply

99: return bypass manual valve 101: roughing mill

102: slab cutter 103: finishing mill

110: valve for controlling the furnace circulating water 111: control valve for recovering the waste heat of the furnace

112: expansion tank level control valve 113: pressure control valve

114: valve for steam temperature control 115: valve for flow control                 

120: thermometer input card 121: temperature control valve output card

122: multi-point analog input and output processing card 123: central processing unit

130: hot water heater device

The present invention relates to a power reduction device using waste heat of a hot-rolled furnace configured to maximize energy consumption of waste heat generated in a hot-rolled furnace of a steel mill, thereby contributing to energy saving and improving productivity.

As shown in FIG. 1, an auxiliary device for regenerating and servicing pure water and supplying it to the skid pipe is used for the purpose of extending the life of the skid pipe, which is a slab feeder installed in the furnace, and preventing corrosion. The device is configured to continue to operate until the level of the pure storage tank 8 becomes high by supplying pure water by operating the shutoff valves 20, 21, and 22 when the level of the pure storage tank 8 becomes below the minimum value. It is configured to sample the pure water in the pure water storage tank (8) and request water quality analysis to perform pure resin regeneration when the water quality is found to be low. The system is configured so that the resin recycling step is performed when the resin recycling step in the column 7 is performed and the heating tank 1 is at a temperature control value of 40 ° C. or lower.

2 is a conventional temperature control device to detect the temperature by the heating tank control thermometer 32 so that the temperature of the heating tank 1 can be always maintained at 40 ℃ and the heater control panel 31 is the set value of the field operation panel and Indication device can be monitored and heater 33 is operated by heater power supply panel 30 according to the temperature control (PLC) program. Fuses, conductors, relays, heaters, etc. are damaged, and when the resin is regenerated, management temperature (40 ℃) or less is generated, and automatic operation is stopped during resin regeneration. The pure water is designed to be about 200㎥, and the industrial water consumed during the resin regeneration is about 70㎥, so when the regeneration is poor, the pure water in the pure water storage tank 8 needs to be replaced again. To the consumption of the office it is weighted, and there is a problem such that the first resin is at least 5 hours for a long time is required to play the load's operation time increases.

3 is a device for returning the circulating water (pure water) in the pipe to protect the skid pipe inside the hot-rolled heating furnace. The furnace circulating water pump 11 is turned on by the shutoff valve 29 for switching the furnace circulation water. It is configured to continue to return the circulating water by selecting, and the waste heat of the circulating water is first recovered from the circulating water heat exchanger (50) for heating oil tank heating, heating, etc. The valve 110 and the control valve 111 for recovering waste heat of the furnace are configured to control the temperature and flow rate. The furnace circulating water cooling tower 60 is a target value of the circulating hot water supplied to the furnace skid pipe. It is a device for cooling so that the circulating water passed through the furnace circulating water cooling tower 60 is supplied to the skid pipe installed in the hot-rolled furnace body 40, the skid wave in the furnace furnace It is configured to be able to prevent the deterioration of print occurs.

4 is a device for reconstituting hot water recovered primarily in a circulating hot water line of a heating furnace to configure hot water used in a hot rolling mill, for example, for oil tank heating, wherein the hot water circulated in a furnace is heated in a circulating furnace. The heat is first recovered by the heat exchanger device 50, the furnace 110 control valve 110 for controlling the circulation water and the furnace waste heat recovery control valve 111 are configured to control temperature and flow rate, respectively, The circulating water for the oil line primarily heated in the circulating water heat exchanger 50 is a device configured to be heated to the secondary in the steam heat exchanger 80 to become a target value. This device is configured to control the temperature to the target temperature by the steam temperature control valve 114, the oil line circulation hot water detected by the steam thermometer 15 and heated to the target temperature for each process The hot rolled furnace was supplied to the main body 40, the rough rolling mill 101, the slab cutter 102, the finishing mill 103, and then recovered and collected again and collected in the expansion tank 70 to perform oil line circulating water level control. It is configured to monitor the level in the expansion tank 70 and to operate the expansion tank level control valve 112 by automatic level control by the expansion tank level control valve 112 and the expansion tank level transmitter 14, The hot water circulated in the line is a device configured to recycle by the pump 13 because the pressure is reduced.

The present invention is to minimize the water quality defects generated during the regeneration and supply of the pure water used to extend the life of the skid pipe, the slab transfer device of the hot-rolled heating furnace, the heating method of the heating tank currently used in the electric heater type It recovers waste heat by hot-rolled heating and improves it with hot water heating method, and improves energy energy efficiency by maximizing the recovery of waste heat generated in hot-rolled heating furnace, and avoids the conventional electric heating method and consumes used in hot-rolled heating furnace. Not only can the power be reduced, but the excessive use of industrial water can be suppressed by eliminating the trouble factors such as fuses, conductors, relays, and heaters, which are common problems in PLC program heating. Reduce the operator's load and reduce maintenance and material costs. Heating a hot-rolled to provide an effect such as that which is intended to provide a power reduction apparatus using the waste heat.

Hereinafter, with reference to the accompanying drawings, the present invention for achieving the above object will be described in detail.

Figure 5 shows the overall configuration of the device to achieve the present invention, the heater and PLC device used to heat the existing heating tank (1) is configured to be monitored and operated in the heating furnace monitoring graphic panel 91 Then, the temperature is detected by the heating tank control thermometer 32 and the heating tank hot water control valve 93 is operated to control the target temperature (40 ° C.). However, due to the characteristics of the control valve, an internal leak may occur and the temperature of the heating tank 1 may rise. Therefore, a shut-off valve is attached to the front and rear ends of the heating tank hot water control valve 93, and the operation procedure is the heating tank 1 When the temperature falls below the target value, the hot water supply shutoff valve 95 is operated and the next return shutoff valve 94 is operated such that the oil line circulating water flow rate is supplied to the heating tank 1, and the heating tank ( When the temperature of 1) becomes the target value, the valve 93 is closed and the return shutoff valve 94 and the hot water supply shutoff valve 95 are configured to close the temperature of the heating tank 1 so that the temperature is always 40 ° C. The return cut-off valve 94 and the hot water supply cut-off valve by the apparatus of the heating furnace control panel 90, the monitoring graphic panel 91, and the communication cable 92, so that the operator of the cab can monitor and operate. 95, configured to operate the heating tank valve for controlling hot water do.

That is, the present invention is an oil line circulation pump 13 for returning the oil line circulation hot water as shown in FIG. 5, an expansion tank 70 for replenishing the circulating water industrial water consumption and automatic evaporation to the oil line, and an expansion tank 70. Expansion tank level transmitter (14) for monitoring the level of the tank and indicating the site level, expansion tank level control valve (112) for automatically filling when the level decreases, and the furnace for recovering waste heat from the furnace Circulating water heat exchanger (50), heating furnace circulating water heat exchanger (50) can increase the heat exchange efficiency and control the furnace circulating water control valve 110, oil line circulating hot water to control the temperature and flow rate of the primary side skid pipe The control valve 111 for controlling the flow rate and temperature, the hot water supply shutoff valve 95 for controlling the inflow and blocking of the oil line circulation hot water to the heating tank (1), the temperature of the heating tank (1) as a target value I can keep it always The temperature of the heating tank hot water control valve 93, the hot water supply shutoff valve 95 and the heating tank hot water control valve 93 and the manual valve 96, which can block the circulating hot water at the time of repair and repair, Manual valve (98) which can be operated manually, heat exchanger that can raise the temperature of heating tank (1), heat exchanged oil line circulating water is sent back to return line and prevent backflow to heating tank (1) Return shut-off valve (94), return shut-off valve (94), manual valve (97) to shut off the oil line circulating water in case of valve abnormality, heating tank control thermometer (32) to detect the temperature of the heating tank (1), control panel 90, a communication cable 92 for connecting between the control panel and the driver graphic panel, and a graphic panel 91 for monitoring and managing the temperature of the field heating tank 1.

6 is an internal configuration diagram of the control panel 90, from a thermometer input card 120 and a multi-point analog input / output processing card 122 for detecting a temperature indication value of a field heater 32 and converting it into a digital signal. There is a central processing unit 123 to process the signal and calculate the output by comparing the target value and the present value, and the temperature control valve output to send the output value of the on-site heating tank hot water control valve 93 The control of the card 121 and the heating tank temperature control algorithm 124 is configured such that the temperature control can be made.

Fig. 7 is a program for controlling a heating tank, in which automatic control is performed by a control valve for controlling a shutoff valve and temperature control and a temperature sequence installed in the tank.

The apparatus of the present invention is to recover the waste heat of the heating furnace to achieve the temperature control of the heating tank (1) to achieve the present invention, the oil line circulation hot water is composed of a closed loop and at the entrance (2.5kg / cm2) A pump 13 capable of stepping down to the exit side (7.0 kg / cm 2), an expansion tank 70 capable of replenishing a shortage of flow rate of the oil line circulation hot water, and an expansion tank level control valve capable of controlling the level of the tank. (112) is installed, and is configured to automatically fill when the level is low, the heating valve circulation control valve 110 is composed of a valve capable of controlling the flow rate and temperature of the skid pipe circulation hot water on the primary side The heating valve waste heat recovery control valve 111 is configured to enable flow rate and temperature control of the oil line circulation hot water on the secondary side. In the configuration of the temperature control device, the oil line circulating hot water passed through the furnace circulating water heat exchanger 50 is operated by the hot water supply shutoff valve 95 and the shutoff valve of the return shutoff valve 94 to heat the heating tank 1. ) Is configured such that hot water is introduced into the hot water, and the heat exchange is performed in the hot water heater device 130 to heat the heating tank 1 to a target temperature, and the thermometer 32 detecting the temperature of the heating tank 1 measures the current temperature in the tank. When detected and displayed on the cab graphic panel 91 via the communication cable 92 device via the furnace control panel 90, the operator checks and monitors the temperature of the field heating tank 1 and sets the target temperature to control the site. It was configured to control the valve 93 for the heating tank hot water control valve, which is a valve, and the oil line circulating hot water that heated the heating tank 1 is reduced back to the circulating hot water return line via the blocking valve of the return blocking valve 94. Let It is configured to minimize the loss of industrial water.

Looking at the internal computing device of the heating control panel 90 for controlling the temperature of the heating tank 1, the temperature of the heating tank control thermometer 32 is input to the thermometer input card 120 as shown in FIG. , The temperature indication value via the multi-point analog input and output processing card 122 is calculated by comparing the target value with the field detection value and the operator in the central processing unit 123, and the output value corresponding to the deviation is multi-point analog input and output processing card. It is configured to send from the thermometer control valve output card 121 to the heating tank hot water control valve 93 which is an on-site control valve via the valve 122, and the control formula of the central computing unit 123 is a heating tank temperature control. It is programmed to be calculated by algorithm 124.

The present invention as described above is configured to maintain the temperature of the heating tank 1 at all times by using the waste heat generated in the hot-rolled furnace to minimize the poor temperature control of the heating tank (1) and at the same time stabilize the equipment It completely compensates the problems caused by poor temperature control and resin service, and maximizes the waste heat recovery, thereby improving the energy efficiency and restraining excessive use of industrial water. It reduces the load and also reduces the maintenance cost and material cost by suppressing the frequent occurrence of PLC failure, thereby reducing the loss of opportunity cost incurred.

Claims (1)

Valve circulating water control valve for increasing the heat exchange efficiency and controlling the primary skid pipe temperature and flow rate in the furnace circulating water heat exchanger 50 and the furnace circulating water heat exchanger 50 capable of recovering the furnace waste. (110), a heating valve for controlling the flow rate and temperature of the oil line circulation hot water, the control valve 111 for recovering waste heat, and a hot water supply shutoff valve (95) for inflow and blocking of the oil line circulation hot water to the heating tank (1). And abnormality and repair of the heating tank temperature control valve 93 and the hot water supply shutoff valve 95 and the heating tank hot water control valve 93, which can maintain the temperature of the heating tank 1 at a target value at all times. Manual valve (96) which can block the circulation hot water, return shutoff valve (94) for sending heat exchanged oil line circulation hot water back to the return line and preventing backflow to the heating tank (1), and return shutoff valve (94) To shut off the oil line Manual valve (97), a hot water heater (130) for heating the heating tank, a thermometer (32) for detecting the temperature of the heating tank (1), a control panel (90) and an on-site heating tank (1). Power reduction device using waste heat of the hot-rolled heating furnace, characterized in that it comprises a driver graphic panel (91) for monitoring and managing the temperature of.

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