SU51673A1 - Pr wire boiler with a separator - Google Patents

Description

As is well known, the main disadvantage of conventional steam boilers is their sensitivity to feed water quality. Flush boilers require pure condensate for feeding, with soluble salts up to 10 mg per liter. Even with this amount of feedwater salts, periodic washing of the boiler is required, the issue of which is not fully resolved from the point of view of its cheapness and reliability. In stationary installations, especially when installing direct-flow boilers with high condensate losses, to obtain the required amount of feedwater, installation of dumpfumformers and evaporators is required, and particularly reliable sealing of condensers and other equipment, where sucked uncleaned water can occur. and distillate. Different designs of rotary boilers differ mainly in solving the problem of combating salt precipitation in the so-called transition zone between the evaporative and superheating parts. This issue is mostly resolved by improving the quality of nutrition.

water and periodic flushing. In Benson's boilers and some of the Ramzin's boilers, the transition zone is transferred to the zone of low gas temperatures, and washing of individual coils is performed while the boiler is running. In other constructions, for example, Sulzer, a vapor separator is installed into which wet steam enters, in which salts are still dissolved in moisture. The moisture is separated and removed from the boiler along with the dissolved salts through the expansion vessel and condensation pots to the outside, and clean steam enters the superheater.

The disadvantage of this system is a large loss of feed water in the purge (up to 10%), the need for a corresponding significant increase in water treatment, an increase in consumption for auxiliary power needs (within), a reduction in the station operation efficiency by 1–2 ° / o. for reducing the amount of steam taken for regeneration from the turbines, and increasing the heating surface of the heating part of the boiler unit due to the increase in the amount of water heated in it. Natural circulation units have the advantage of being less sensitive to feedwater quality, but they are much more cumbersome due to the large size of the boiler drums and the excessive parasitic weight of recirculation pipes that are poorly or not heated at all. Aggregates with forced multiple circulation (syst. La Montté) are also of little sensitivity to the quality of feedwater, but require the installation of an additional transfer pump and are less convenient for assembly than a direct flow boiler.

Less sensitive to the quality of feedwater in boilers with multiple natural and forced circulation is due to the fact that when fed with water containing soluble salts, steam is always released in the presence of significant amounts of water, in which salts that fall out of steam dissolve . Significant salt concentrations can be obtained in the boiler, but with a relatively small percentage of blowdown (1-2 ° / o), sufficient purity of the superheating heating surfaces can be achieved. The decisive factor is the quality of operation of the separating devices, which basically determine the question of the required size of the extraction solution of a concentrated salt solution, i.e., boiler water.

The proposed steam steam boiler scheme tends to maximally combine the advantages of boilers with single forced circulation and the advantages of boilers with multiple water circulation in relation to sensitivity to feed water quality. To this end, it is proposed to maximize the principle of flow in the entire zone where there is no danger of precipitating soluble salts from moisture, and to use the advantages of multiple circulation only where it really is necessary, i.e., to prevent the precipitation of salts.

The drawing shows a diagram of a flow boiler with a separator.

The boiler layout basically resembles a conventional boiler layout.

with the separation of moisture from the steam, but with the main difference that the moisture released from the steam produced in the steam generating elements 5 of the flow boiler is not completely removed, but is evaporated in special evaporation pipe elements 2 heated by the boiler gases (in the furnace or flues). Pipe elements 2 are included in a separator 7 located between the heating surface of the steam generator and superheater 4. These elements are under the same pressure as the boiler, but to prevent the salt from falling in them, repeated natural or forced circulation is created to prevent the soluble salts from falling out. heating surfaces. It was possible to raise the question of the implementation of these flow elements with secondary separation, but the circulation scheme in this case is more flexible and reliable.

Since the concentration of salts in the boiler water of the circulating elements can increase all the time, by blowing a part of the water this concentration is maintained in the maximum but permissible limits. The choice of the scheme of forced or natural circulation in their elements is determined only by the conditions of the constructive arrangement of the boiler unit and does not have a decisive fundamental importance.

The steam produced in the circulation elements is separated from moisture and, together with the steam, is fed from the recirculating boiler to the superheater 4, in which the danger of salt excretion no longer exists. Consequently, the quality of feedwater for such an aggregate, in its overwhelming majority of the flow, may be approximately the same as for La Mont or natural circulation boilers (permuted water). Thus, the main difficulties associated with the use of recirculating boilers are eliminated.

Thus, the dangerous transition zone between the evaporating and superheating part of the heating surface is carried out with repeated circulation and continuous blowing. The separated moisture is evaporated in a separator with natural circulation. Excess salt is removed from the separator by conventional purging.

The low load (maximum total power) of the natural circulation separator makes it easy to arrange it in a common unit with a flow element without significant increase compared with a conventional flow boiler.

The subject matter of the invention.

A continuous boiler with a separator connected between the heating surface of the steam generator and the superheater, characterized by the use of pipe elements 2 with natural or forced circulation, included in the same cenapafop 7, which includes steam generating elements in the straight part of the boiler.

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