JPH05223207A - Drain reducing device for auxiliary vapor system - Google Patents

Abstract

PURPOSE:To reduce an operating cost by preventing total drain of supply water and reducing the supply water. CONSTITUTION:An auxiliary vapor system having an auxiliary boiler 21 has a condensed water flow-control system for continuously supplying condensed water to a feed water drain tank 26 so as to constantly control a water level of a condensed water tank 23, a supply water flow-system for controlling a flow rate of supply water to the tank 26 in response to the level of the tank 26, and a closed coolant system for cooling the supply water to be supplied to a blow water cooler 35 and circulating it.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an auxiliary steam system for supplying steam to a steam load inside a plant, and more particularly to an auxiliary steam system drain for reducing the amount of drain discharged to the drain system of an auxiliary boiler. It relates to a reduction device.

[0002]

2. Description of the Related Art Generally, an auxiliary steam system supplies steam to a steam load in a plant. As shown in FIG. 2, steam generated in an auxiliary boiler 1 is supplied to various loads 2 in the plant. After that, most of the water becomes condensed water and is collected in the condensed water tank 3.

The condensate water level collected in the condensate tank 3 is detected by the condensate level switch 4, and when the condensate level rises to a predetermined level, the condensate pump 5 is started to operate.
Water is supplied to the water supply drain tank 7 through the condensate pump outlet valve 6.

The water supply stored in the water supply drain tank 7 is supplied to the auxiliary boiler 1 by a water supply pump 8.

The overflow water of the water supply drain tank 7 and the continuous blow water of the auxiliary boiler 1 are sent to the blow tank 11 by the overflow pipe 9 and the blow pipe 10, respectively, and are temporarily stored therein.

The hot water temporarily stored in the blow tank 11 is cooled by the blow water cooler 12, and the cooling water is discharged to the drain pits 13, 13.

Further, as described above, most of the steam from the steam load 2 becomes condensate and is recovered in the condensate tank 3, but the replenishment water pipe 14 is used to replenish the water that has not been recovered. When the water supply level switch 15 is connected to the tank 7 and detects that the water level of the water supply drain tank 7 has dropped to a predetermined water level, the makeup water valve 16 is fully opened,
The required amount of makeup water is supplied to the water supply drain tank 7 through the makeup water pipe 14.

The makeup water is also supplied to the feed water pump 8 and the blow water cooler 12 through the cooling water pipe 17, so that the makeup fluid can lower the internal fluid of the feed water pump 8 or the like to a predetermined temperature. The supplied makeup water is completely discharged to the drain pits 13, 13.

[0009]

However, in such a conventional auxiliary steam system, the condensate recovered from the condensate tank 3 to the feed water drain tank 7 returns intermittently with a time delay and replenishment. Since the entire amount of water was discharged to the drain pits 13 and 13, there were the following inconveniences.

That is, the condensate returned to the water supply drain tank 7 is temporarily stored in the condensate tank 3, and the condensate pump 4 is turned on and off by the High and Low signals of the condensate level switch 4. By repeating the operation, the water intermittently returns to the water supply drain tank 6.

However, even if the amount of water supplied from the water supply drain tank 7 is reduced by the water supply pump 8 and the water level rises, a large amount of condensed water returns to the water supply drain tank 7 with a time delay. Often, the water level in the water supply drain tank 7 suddenly rose and the water supply overflowed from the overflow pipe 9.

When the water level in the water supply drain tank 7 is lowered, the water level switch 4 is set to High or Low.
The makeup water is intermittently supplied to the feed water drain tank 7 by repeating the full-open-full-close operation of the makeup water valve 16 by the (high and low) signals, so that the above-mentioned condensate is accompanied by a time delay. When returning to the water supply drain tank 7, the water level of the water supply drain tank 7 rises sharply and overlaps with the condensate, and the water supply overflows from the overflow pipe 9.

Further, the makeup water is also supplied to the water supply pump 8 and the blow water cooler 12 through the cooling water pipe 17, and the supplied makeup water is completely discharged to the drain pits 13, 13.

Therefore, the drained or overflowed drain is discharged to the drain pits 13 and 13 and transferred to the wastewater treatment facility in the plant (not shown), but the drainage discharged from the auxiliary steam system is, for example, about 20 tons. A large amount of water costs equivalent to the amount of drain,
There is a problem that wastewater treatment costs are extremely high and operating costs are high.

The present invention has been made in view of these circumstances, and an object thereof is to reduce the amount of drainage discharged to the drain system of the auxiliary boiler to reduce the operating cost of the auxiliary steam system. It is to provide a drain reduction device.

[0016]

The present invention is configured as follows to solve the above problems.

That is, according to the present invention, an auxiliary boiler for supplying steam to a load, a condensate tank for storing condensate from the load, condensate from the condensate tank is stored as feed water, and makeup water is supplied. A water supply drainant for receiving water, a water supply pump for supplying water supply from the water supply drain tank to the auxiliary boiler, a blow tank for storing blow water from the auxiliary boiler and overflow water from the water supply drain tank, and An auxiliary steam system having a blow water cooler for cooling hot water from a blow tank with a part of the makeup water, and the condensate is continuously fed to the condensate drain to control the water level of the condensate tank to a constant level. A condensate flow rate adjusting system for supplying water to the tank, and a make-up water flow rate adjusting system for controlling the amount of make-up water supplied to the water supply drain tank according to the water level in the water supply drain tank. Characterized in that a cooling water system constituting a closed loop for circulating and cooling the makeup water is water in the blow water cooler.

[0018]

[Function] The water level in the condensate tank is controlled to be constant by the condensate flow rate adjusting system, and the condensate is continuously transferred to the water supply drain tank.

Further, the water level of the water supply drain tank is controlled to be constant by the water supply flow rate adjusting system, and the amount of makeup water corresponding to the water supply level is supplied to the water supply drain tank. This allows
It is possible to prevent the water level of the water supply drain tank from rising rapidly and overflowing.

Furthermore, since the cooling water for cooling the blow water from the auxiliary boiler is circulated in the closed loop cooling water system,
In addition to reducing the amount of make-up water supplied, the amount of make-up water discharged to the drain pit as in the conventional example is greatly reduced.
It is possible to save makeup water and reduce operating costs.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG.

FIG. 1 is a block diagram showing the overall construction of an embodiment of the present invention. In the figure, the auxiliary steam system is an auxiliary boiler 21, a load 22, a condensate tank 23, a condensate pump 24,
The condensate pump outlet valve 25, the feed water drain tank 26, and the feed water pump 27 are sequentially connected by a primary loop line 28 to form a primary closed loop for circulating cooling water.

The water supply drain tank 26 is connected to the inlet of the cooling water tank 30 via an overflow pipe 29 for transferring the overflow water, and the outlet of the cooling water tank 30 is connected via a pipe 31 to the cooling water pump 32 and the chiller unit 3.
3 connected in sequence to the outlet side pipe 3 of the chiller unit 33
4 is branched into two forks 34a and 34b, one branch pipe 34a is connected to the secondary side of the blow water cooler 35, and the other branch pipe 34b is connected to the water outlet of the water supply pump 27. .. The chiller unit 33 may be an air-cooled type, a water-cooled type, or an electric type or another type.

On the other hand, the auxiliary boiler 21 has a blow pipe 36a for transferring the continuous blow water connected to the blow tank 36.

The blow tank 36 supplies the continuous blow water to the primary side of the blow water cooler 35, and the blow water cooler 3
5, the cooling water stored in the cooling water tank 30 is passed through the cooling water pipe 34c to cool the continuous blow water by the cooling water, and then the drain pit 3
It is released to 7.

The water supply pump 27 cools the water supply with the cooling water from the cooling water tank 30.

On the other hand, the feed water drain tank 26 is connected to a make-up water source (not shown) through a make-up water pipe 38 on the inlet side thereof to receive make-up water. Is provided with a make-up water master valve 39 for passing a large amount of make-up water and a bypass pipe 40 for bypassing the make-up water, and a make-up water sub-valve 41 for letting a small amount of make-up water pass through the bypass pipe 40. I am intervening. These make-up water parents, child valve 3
9 and 41 are electrically connected so as to be controlled in opening degree by a water supply level control device 42 for controlling the water level of the water supply drain tank 26 at a constant level to form a makeup water flow rate adjusting system.

That is, when the water level drop in the water supply drain tank 26 is small, the opening degree of the makeup water sub-valve 41 is adjusted to a minute opening degree, and when the water level drop is large, the makeup water parent / child valves 39, 4 are provided.
Both 1 are fully opened.

A condensate level control device 43 is provided in the condensate tank 23, and the condensate tank 3 is supplied from the outlet of the condensate pump 24.
By providing the minimum flow pipe 44 for returning the condensate, the condensate flow rate adjusting system is configured, the opening degree of the condensate pump outlet valve 45 can be adjusted, and the condensate pump 24 can be continuously transported. ..

That is, when the water level in the condensate tank 23 is small, the opening of the condensate pump outlet valve 45 is adjusted to a small opening, and the condensate continuously transferred by the condensate pump 24 is a minimum flow pipe. It returns to the condensate tank 23 through 44, and when the water level drops significantly, the condensate pump outlet valve 25 is fully opened to reduce the return of the condensate and to supply almost the entire amount. There is.

The chiller which communicates with the cooling water pipe 34c from the upstream side of the makeup water parent and child valves 39 and 41 so that the cooling water can be supplied even when the operation of the cooling water pump 32 and the chiller unit 33 is stopped. The bypass pipe 46 is connected to the makeup water pipe 38. A chiller unit bypass valve 47 is provided in the middle of the chiller bypass pipe 46. In FIG. 1, reference numeral 48 is a drain pit of the cooling water tank 30.

Next, the operation of this embodiment will be described.

After the steam generated in the auxiliary boiler 21 is supplied to various steam loads 22 in the plant, most of the steam becomes condensed water and is collected in the condensed water tank 23. The water level of the water supply tank 23 is constantly controlled by the condensate level control device 43 of the condensate flow rate adjusting system, and the condensate pump 24 and the condensate pump outlet valve 25 continuously transfer the condensate to the water supply drain tank 26.

The water supply stored in the water supply drain tank 26 is supplied again to the auxiliary boiler 21 by the water supply pump 27 as water supply. The water level of the water supply drain tank 26 is constantly controlled by the water supply level control device 42, and a plurality of flow rate adjusting valves, for example, a makeup water master valve 39 capable of passing a large amount of makeup water and a small amount of makeup water are passed. A make-up water valve 41 capable of supplying water supplies an amount of make-up water according to the water supply level.

The cooling water that has cooled the water supply pump 27 and the blow water cooler 35 and has been heated to, for example, about 7 ° C. to 12 ° C. returns to the cooling water tank 30, is pressurized by the cooling water pump 32, and is fed to the chiller unit 33. It is transferred and cooled again to about 7 ° C. In this way, the cooling water circulates in the secondary loop line on the closed loop.

Therefore, according to this embodiment, the water level in the condensate tank 23 is constantly controlled by the condensate level control device 43, and the condensate pump 24 and the condensate pump outlet valve 25 continuously supply condensate water. Not only can it be transferred to the drain tank 26,
The water level of the water supply drain tank 26 is controlled to be constant by the water supply level control device 42, and a plurality of makeup water parent and child valves 39,
Since the supply water amount according to the water level can be supplied by 41, it is possible to prevent the water supply level of the water supply drain tank 26 from rapidly rising and overflowing.

Further, a cooling water pump 32 that circulates the cooling water, a chiller unit 33 that heats the cooling water to lower the temperature, and a cooling water tank 3 that can temporarily store the cooling water.
Since 0 and 0 are circulated in the closed loop secondary loop line, the conventional drain pit 13 (see FIG. 2)
It is possible to save about 20 tons of make-up water that had been completely discharged to Therefore, it is possible to reduce the water supply cost corresponding to the drain amount, which has been extremely high in the past, the wastewater treatment cost, and the like, and it is possible to reduce the operating cost of the entire plant.

Further, a chiller bypass pipe 46 communicating with the cooling water pipe 34 from the upstream side of the makeup water parent and child valves 39 and 41.
Since the chiller unit bypass valve 47 is provided in the middle of the chiller bypass pipe 46, the cooling water can be supplied even when the cooling water pump 32 and the chiller unit 33 stop operating. There is no effect on the original function of storing heat in the water cooler 35.

[0039]

As described above, according to the present invention, the water level of the condensate tank is controlled to be constant, the condensate is continuously transferred to the water supply drain tank, and the amount of makeup water corresponding to the water level is supplied to the water supply drain tank. Since the water is supplied, it is possible to prevent the water level in the water supply drain tank from rapidly rising and overflowing.

Further, since the cooling water of the blow water cooler for cooling the blowing water is circulated in the closed loop cooling water system, it is possible to reduce the amount of make-up water drained to the pit and reduce the operating cost.

[Brief description of drawings]

FIG. 1 is a block diagram showing the overall configuration of an embodiment of an auxiliary steam system drain reduction device according to the present invention.

FIG. 2 is a block diagram showing the overall configuration of a conventional auxiliary steam system.

[Explanation of symbols]

 21 Auxiliary boiler 22 Load 23 Condensate tank 24 Condensate pump 25 Condensate pump outlet valve 26 Water feed drain tank 27 Water feed pump 29 Overflow piping 30 Cooling water tank 32 Cooling water pump 33 Chiller unit 35 Blow water cooler 36 Blow tank 37 Drain Pit 38 Make-up water pipe 39 Make-up water master valve 41 Make-up water child valve 42 Water level control device 43 Condensate level control device 44 Minimum flow pipe 46 Chiller bypass pipe

Claims (1)

[Claims] 1. An auxiliary boiler for supplying steam to a load, a condensate tank for storing condensate from the load, a condensate from the condensate tank for use as feed water, and a make-up water for receiving. A water supply drain tank, a water supply pump for supplying the water supply from the water supply drain tank to the auxiliary boiler, a blow tank for storing blow water from the auxiliary boiler and overflow water from the water supply drain tank, and from this blow tank. To the auxiliary steam system having a blow water cooler that cools the hot water of a part of the makeup water, and continuously supplies the condensate to the feed water drain tank in order to control the water level of the condensate tank to a constant level. A condensate flow rate adjusting system, a makeup water flow rate adjusting system that controls the amount of makeup water to be supplied to the feed water drain tank according to the water level in the feed water drain tank, and the blow water cooling system. A drain reducing device for an auxiliary steam system, comprising: a cooling water system that forms a closed loop that cools and circulates makeup water that is supplied to a waste container.