SU908749A1 - Multistage evaporation plant - Google Patents

Description

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The invention relates to a power system and can be used) in thermal power plants.

(tes)

A multi-stage evaporator unit is known, containing boiling-type vertical tube evaporators communicated via a heating pair with steam extraction pipelines from a turbine, and via a secondary steam line with a regeneration system of the joint venture.

The disadvantage of this setup is that only deeply dried water is used as nutrient thieves, the cost of which is relatively high.

Also known is a multistage evaporative installation comprising a head preheater and circulation circuits of a concentrate, each of which contains a series-connected circulation pump, regenerative preheaters located in the regeneration steps, gond.ng

heaters placed in the steps of heat release and communicated through the overflow devices of the regeneration step and the heat release stage of heat, and the heat release steps of the last circulation circuit are connected through a heating pair with end heaters 21.

A disadvantage of the known installation is its high cost due to the large heat exchange surfaces of the heaters.

The purpose of the invention is to reduce metal consumption by reducing the total heating surface.

This goal is achieved by the fact that the installation is equipped with additional end heaters, communicated through a heating pair with heat release stages, in which the circulation loop head heaters are located.

The drawing shows a schematic diagram of a lot of gunnagchch and xiaaritel. 1 st installation with three circulation circuits of the concentrate.

The installation; the NKA contains evaporation stages 1, the first of which is connected to the main 1-heater heater 2, communicated via a heating pair with pipe 3 of the turbine steam extraction, to which the regenerative turbine of the condensate of the turbine unit is connected. The plant has 5 circuits of concentrate circulation, each of which contains a series-connected scrubbing pump 6, regenerative heaters 7 located in stages 8 of regeneration, head heaters 9 placed in stages 10 of heat release. Steps 8. and 10 of regeneration and heat release are interconnected by unregulated overflow devices 11. Stage 10 heat release of the last concentrate circulation circuit 5 through the heating pair is communicated with end heaters 12 included in path 13 of the main condensate of the turbine plant, which also includes additional end heaters 14. The latter are connected along a heating pair to the heat removal stages 10, in which the head heaters of 9 circuits 5 of circulation are placed. The discharge nozzle 15 of the circulation pump 6 of the circulation circuits 5, except for the latter, is communicated through an adjustable overflow device 16 with a regeneration stage 8. The plant is equipped with pipelines 17 and 18 for purging and supplying feed water.

The installation works as follows.

The concentrate of the last stages 1 of evaporation (steps 10 of the heat release) of the circuits 5 of the circulation of the concentrate is pumped by the circulation pumps 6 through the regenerative heaters 7. Next, the concentrate flow passes through the head heaters 9. Heated in the regenerative and head heaters 7 and 9 concentrate enters the first the evaporation stage 1 (regeneration stage 8) of the corresponding concentrate circulation circuit 5. Then concentrate through HeperyjmpyeMbie overflow devices 11 flow from the first CTyiTf .; 1 isttsarsnn in the second of the second and third, etc. until the last. In each of the evaporation stages 1, the concentrate instantaneously forms with the formation of secondary steam due to pressure drop over the stages r - 1 evaporation. The secondary steam from the regeneration stages 8 of each circulation loop 5 enters the regenerative heaters 7. The secondary steam of the first and second heat discharge stages 10

Circuit 5 Circulation is supplied

to the corresponding additional end heaters 14 and head heaters 9, and in the third circulation circuit 5 to the end heaters 12. The heating steam from the extraction line 3 of the turbine is supplied to the main head preheater 2. Feed water is supplied through supply line 18 in the first step 8

regeneration, and the purge concentrate is discharged from the last stage 10 of the heat release. With the help of adjustable overflow devices 16, the required amount of concentrate from the previous circulation circuit 5 can be diverted to the regeneration step 8 of the next circulation circuit 5. The presence of several circuits 5 of the concentrate circulation ensures a different degree of concentrate concentrate along the contour 5. If the operating conditions of the installation require equal temperature differences of the evaporation stages, then the flow rate of the concentrate in each of the circuits 5 of the circulation should be different. Moreover, in the first circulation loop 5, the concentrate flow should be the largest and refer to the concentrate flow in the second, third circuits 5 as 3: 2 and 3: 1, respectively (if the flow in the third circuit 5 is equal to the cooling water flow). In the same case, when, according to the operating conditions, it is required to ensure equal consumption of circulating concentrate along circuits 5, the temperature difference in the third circuit 5 should be the smallest and relate to temperature differences in the second and first circuits 5, respectively, as 1: 2 n 1: 3 (if the concentrate flow is equal to the cooling water flow).

5 The presence of additional end heaters under other conditions (equality of production, number of contour, number of evaporation stages in each circuit and equality of concentrate costs in the contours) allows reducing the metal intensity of the installation by reducing the total heating surface of the heaters. With equal costs in all three circuits, the temperature difference in the second and third circuits can be significantly reduced. It reduces temperature drops

and increases the underheating in the heaters, which reduces the specific (related to 1 t / h capacity) installation surface and its cost.

Claims (2)

1. Sterman L.S. Evaporators. M., Mashgiz, 1956, p. 12. 2. A breath of L.10. Use of marine -. waters for thermal power stations M., Energie, 1974, p. 125-133 (prototype).