Overcritical heat supply unit secondary condensate pump system
Technical field
The utility model relates to a kind of overcritical heat supply unit secondary condensate pump system.
Background technology
As overcritical heat supply unit; As still by the Subcritical Units mode, the hydrophobic direct entering oxygen-eliminating device of heat exchangers for district heating, Unit Steam Water systemic circulation medium will have less than 20% through condensed water precision processing system; 80% above medium is without the chemical water desalination; Just be difficult to guarantee the boiler feedwater quality, can produce the safety of boiler and have a strong impact on, therefore; Overcritical heat supply unit does not generally recommend to adopt system's connected mode of the hydrophobic direct entering oxygen-eliminating device of heat exchangers for district heating, but gets into the condensate system before the precision processing device.But because condensate precision processing resin can not bear too high temperature, heat exchangers for district heating is hydrophobic can not directly to be entered unit and condenses before the polishing unit, needs through cooling.
For this reason in the middle of the prior art; Design proposes heat supply network is hydrophobic through the external drain cooler of one-level is set; The leader condensate is cooled to it to return condenser after certain temperature; Heated condensate continues to return therrmodynamic system, thereby has promptly satisfied hydrophobic requirement through precision processing, has also taken into account economy simultaneously.
But above-mentioned heat supply network draining system scheme faces with next problem, and that is exactly the selection issue of external drain cooler, and in order to improve heat-economy, the drain temperature that further reduces back condenser just needs to select the plate type heat exchanger of low side difference; Simultaneously, based on the consideration of arranging, also pay the utmost attention to and select plate type heat exchanger for use.Through measuring and calculating, if select pipe heat exchanger for use, its size will be suitable with original heat exchangers for district heating, and this makes Gateway Station in Heating Network arrange very difficulty, and because the increase of heater weight causes the civil engineering initial cost to increase.Therefore from economy and saving floor space, the external drain cooler of heat supply network should be selected plate type heat exchanger for use.
Yet ultra (surpassing) critical heat supply unit condensate pressure rating all meets or exceeds PN4.0, and common plate type heat exchanger can't meet the demands, and must select all-welded structure for use.But consider that there are following two problems in the all-welded structure plate type heat exchanger: one of which, apparatus expensive, the price of separate unit all-welded structure plate type heat exchanger almost are 4 to 5 times of common plate type heat exchanger price; Its two, its reliability is still waiting further raising.It is reported that problem has in various degree all appearred in the all-welded structure plate type heat exchanger that domestic how tame power plant adopts.
The utility model content
The technical problem that the utility model solved is promptly providing a kind of ultra (surpassing) critical heat supply unit secondary condensate pump system, especially refers to low and ultra (surpassing) the critical heat supply unit secondary condensate pump system of operation of a kind of initial cost.
The technical scheme of the utility model is: a kind of overcritical heat supply unit secondary condensate pump system, include condenser, and also include: the one-level condensate pump, the one of which end links to each other with condenser, and the other end links to each other with gland heater; Gland heater, it comprises first water side, second water side and the 3rd water side, and first water side links to each other with heat supply network drain cooler water intake end, and second water side links to each other with first group of low-pressure heater, and the 3rd water side links to each other with condenser; The heat supply network drain cooler, its water side links to each other with the secondary condensate pump, the hydrophobic entering condenser of the heat supply network after the heat exchange; First group of low-pressure heater, its other end links to each other with the secondary condensate pump; The secondary condensate pump, the condensate of reception heat supply network drain cooler and first group of low-pressure heater is delivered to condensate the second group of low-pressure heater that is attached thereto.This one-level condensate pump adopts the vertical preposition condensate pump of low lift, and this secondary condensate pump adopts the more high-lift horizontal pump booster that coagulates.
The beneficial effect of the utility model is: ultra (surpassing) critical heat supply unit secondary condensate pump system that the utility model provides changes traditional single-stage condensate pump into secondary, and promptly the vertical preposition condensate pump of one-level low lift adds the horizontal pump booster that coagulates of the higher lift of upper level.
After adopting the utility model, can bring following positive variation at least:
(1) the relevant low-pressure heater and the pressure rating of gland heater will be that PN4.0 reduces to PN1.6 by original pressure rating, bring the wall thickness of equipment to reduce thus, and then the weight of equipment can alleviate, and the initial cost of equipment also will reduce.
(2) can attenuate from coagulating pump discharge to the wall thickness of booster inlet duct, the tubing consumption can reduce about 25% thus.
(3) will be reduced to PN1.6 from coagulating pump discharge by original PN4.0 to the valve pressure grade of booster inlet duct, along with the reduction of valve grade, the price of valve also can correspondingly reduce, and so also can save a not little initial cost.
(4) the condensate accurate process equipment will become low-pressure system by original medium voltage network, and investment of equipment is also with corresponding reduction.
(5) heat supply network drain cooler type selecting is produced very active influence; This heat exchanger can be selected for use with the similar common plate type heat exchanger of closed Water System; And then the equipment investment of having avoided selecting for use full welded plate formula heat exchanger to bring is high; The problem that operational reliability is low has fundamentally solved the selection issue of drain cooler, has guaranteed the reliability service of heat supply network draining system.
(6) positive impact that utilizes system also to bring to the fume afterheat that possibly go up future makes the whole system pressure rating all reduced to the pressure rating of PN1.6 by the middle pressure grade of original PN4.0, and initial cost can be saved quite big one again.
Following table is to be example with the overcritical heat supply unit of separate unit 350MW, and the contrast condensate system adopts one-level condensate pump scheme and secondary condensate pump scheme initial cost.
Can find out from last table; For the overcritical heat supply unit of separate unit example 350MW; Adopt the secondary condensate pump system of this patent, can save closely 4,000,000 than separate unit unit one-level condensate pump full welded plate formula heat exchanger scheme, also economize nearly 2,000,000 than one-level condensate pump pipe heat exchanger scheme.
Description of drawings
Fig. 1 secondary condensate pump system principle power system diagram hot in nature.
The specific embodiment
As shown in Figure 1, the overcritical heat supply unit of the utility model secondary condensate pump system includes condenser 1; One-level condensate pump 2,3, the first groups of low-pressure heaters 4 of gland heater; Heat supply network drain cooler 5,6, the second groups of low-pressure heaters of secondary condensate pump 7 and oxygen-eliminating device 8.This one-level condensate pump adopts the vertical preposition condensate pump of low lift, and this secondary condensate pump adopts the more high-lift horizontal pump booster that coagulates.These one-level condensate pump 2 one ends link to each other with condenser 1, and the other end links to each other with gland heater 3.Gland heater 3; It comprises first water side 31, second water side 32 and the 3rd water side 33; First water side 31 links to each other with heat supply network drain cooler 5 water intake ends 51, and second water side 32 links to each other with first group of low-pressure heater 4, and the 3rd water side 33 links to each other with condenser 1.Heat supply network drain cooler 5, its water side 52 links to each other with secondary condensate pump 6, the hydrophobic entering condenser 1 of the heat supply network after the heat exchange.First group of low-pressure heater 4 other end links to each other with secondary condensate pump 6; Secondary condensate pump 6 receives the condensate of heat supply network drain cooler and first group of low-pressure heater, condensate is delivered to the second group of low-pressure heater 7 that is attached thereto.
In the present embodiment, first group of low-pressure heater comprise No. 6 and lowly add, lowly add and lowly add three low-pressure heaters No. 8 for No. 7, and No. 5 low add of second group of low-pressure heater for showing among the figure, according to the different situations of system, the number of low-pressure heater can be different.
The operation principle of native system is following: condensate is boosted through first order condensate pump (being preposition condensate pump) earlier from condenser 1 outlet; Again through gland heater heating, and draw a part of condensate net drain cooler (common plate type heat exchanger) that reduces phlegm and internal heat, absorb and turn back to No. 6 behind the hydrophobic part heat of heat supply network and lowly add outlet in the gland heater outlet; With remaining successively through 8; The residue condensate of 7, No. 6 low heating is mixed, and boosts through second level condensate pump (being condensate booster pump) after the mixing again; Get into low adding No. 5, advance the oxygen-eliminating device deoxygenation afterwards again.Heat supply network is hydrophobic then in heat supply network drain cooler (common plate type heat exchanger), be cooled after, be back to condenser.
The above only supplies the usefulness of explanation the utility model, but not the utility model is done any pro forma restriction; The technical staff in relevant technologies field; Under the situation of spirit that does not break away from the utility model and scope; Can also utilize the technology contents of above-mentioned announcement to change or be modified as the equivalent instance of equivalent variations; Therefore, all technical schemes that are equal to also should belong to the category of the utility model, all still belong in the scope of technical scheme of the utility model.