CS242723B1 - Equipment for heat removal from power plants - Google Patents

Abstract

The purpose is to utilize the advantages of steam-water mixing heaters not only for regeneration, but also for heat extraction from the power plant unit. This is achieved by heating the heating water and regenerative heating of turbine condensate with steam from unregulated extractions intended for heat extraction being carried out in dual-purpose, mixing heaters, with the turbine condensate circuit being separated from the heat network by a surface, tubular, counter-current heat exchanger or the heating, turbine circuit being connected directly to the heat network.

Description

The invention relates to a device for removing heat from power plants.

In the energy sector, there is a trend towards a shift from the power plant operation of large 1 nuclear units to cogeneration. The existing heat exchangers for the heating of the forced water are designed as surface tubular heaters.

Kegenerative heating is also carried out in tubular heaters. Low-pressure regeneration systems of large steam turbines with mixing heat exchangers or in combination with surface heaters are known.

Dual-purpose heating heaters are proposed, where the tubular heat transfer surfaces for regenerative condensate heating and heating of the forced water are stored in a common steam space, respectively. in a common cloak.

Hybrid heating heater is also known, where the surface heat exchanger for the heating of the sieve water forms a unit with a mixing heater of the turbine condensate.

The prior art apparatuses and methods of heating are considerably expensive in terms of material and investment, notwithstanding the energy losses due to the temperature difference between the saturation temperature of the heating steam in the respective consumption and the outlet temperature of the condensate, respectively. forcing water from the respective surface heater.

In all types of known dual-purpose heaters, the question of reliably separating the condensate from the regeneration part and from the hot water part is not solved.

This requirement results from the different water qualities of the turbine circuit and the silo water circuit. The likelihood of leakage and ingress of forced heating water into the turbine circuit increases the relatively high sieve water pressure over the heating steam pressure.

These drawbacks are eliminated by the heat removal device of the thermal power plants according to the invention. SUMMARY OF THE INVENTION The supply of the steam from the uncontrolled steam condensation turbine withdrawals for regenerative heating of turbine condensate and for heating purposes is effected by piping to dual-purpose mixing heaters, the turbine heating circuit including the heating and return pipes being separated from the heat network between the exchanger. heat.

The device according to the invention with dual-purpose mixing heaters allows to reduce the weight and dimensions of the heat exchangers, reduce investment costs and increase the reliability of the device. Another benefit is the reduction of space requirements in exposed areas of the engine room, simplification of the reconstruction of condensation blocks for heating operation and reduction of exergetic losses.

An example of an embodiment of the invention is shown in the drawing, wherein Fig. 1 shows a functional wiring diagram of the device according to the invention and Fig. 2 a diagram of an alternative embodiment, in an application at a nuclear power plant.

The steam from the low pressure, unregulated steam turbine draws J is introduced through line 22,

H1, 25 to dual-purpose mixing heaters 12. 13. JX, Jg, which are disposed so that gradually heated water (condensate) can fall by gravity from heaters 13 to heater 13 and further from heater 13 to heater 14 via syphons g. that prevent backflow of steam.

The height differences of the individual heaters Jg, XJ, JX, 15 gradually increase with the increase of pressure differences in the subsequent steam offtakes. The nominal pressure of the spring in the peak heater 15 is about 0.5 MPa and, for reasons of layout, this heater can no longer be placed in the corresponding height difference below the heater JX.

Therefore, feed pumps 4 are used here. A portion of the heated water is pumped from the starter heater 15 to the degasser 8, and from the feed tank 5 the feed water is passed through the high pressure regeneration to the steam generator.

A second portion of the heated water from the Sink heater 15 is discharged via a duct 26 to a tubular countercurrent exchanger 12. wherein the heat is transferred to a distant heating sieve water circuit and returned via line 28 to the heater.

The sieve water pressure in the intermediate exchanger 12 is maintained equal to or less than the pressure on the turbine condensate side, which is achieved by suitably dimensioning, deploying, and operating the pumping stations 19. This measure reduces the possibility of ingress of force water into the turbine condensate circuit.

Advantageously, in view of the relatively small price differences between the demineralized water of the power plant circuit and the decarbonized water for long-distance transport and the heating network, both demi-water circuits can be operated, and the heat exchanger 17 is eliminated.

In this case, the second part of the heated water from the heater 15 is discharged directly to the heating network 11, as indicated in FIG.

The heated heating water for the heating network can be withdrawn behind the heater 11, depending on operating needs, and in this case the feed pumps 16 are put into operation.

The pressure before entering the first dual-purpose mixing heater is regulated by a valve to prevent evaporation in the intermediate exchanger 12 · "

Excessive pressure lines at the outlet of the intermediate heat exchanger 12, respectively. The return force water, in the alternative without an intermediate heat exchanger, can advantageously be processed in a water turbine instead of throttling and used to drive a suitable pump or electric generator.

Depending on the temperature of the return heating water in line 30, 30, this is fed via line 28 to the mixing heater 16 or to the mixing heater 12. that can serve as a hurry.

The outlet tipping heater 12 can preferably be designed as a surface (tubular) heating heater according to FIG. 2.

The device according to the invention with dual-purpose mixing heaters allows to reduce the weight and dimensions of the heat exchanger, reduce the investment costs and increase the reliability of the device. Another benefit is the reduction of space requirements in exposed areas of the engine room, simplification of the reconstruction of condensing units for heating operation and reduction of energy losses.

Claims (2)

SUBJECT OF THE INVENTION 1. A device for removing heat from thermal power plants, characterized in that the supply of off-take steam from unregulated steam condensation turbine p) for regenerative heating of the turbine condensate and for heating purposes is provided by piping (22, 23, 24, 25) to dual-purpose mixing heaters. (12, 13, 14, 15), wherein the turbine heating circuit including the heating pipe (26) and the return pipe (27, 28) is separated from the heating network (18) by the intermediate heat exchanger (17) or the heating pipe (26) and the return pipe the conduit (27, 28) is directly connected to the thermal network (18) by the conduit (29, 30). Device according to claim 1, characterized in that the output dual-purpose heater (15) is of the surface type.