CN113673112A - Method and system for determining water production cost of water-electricity cogeneration unit - Google Patents
Method and system for determining water production cost of water-electricity cogeneration unit Download PDFInfo
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Abstract
The invention provides a method and a system for determining the production cost of water production of a water-electricity cogeneration unit, aiming at the specific water-electricity cogeneration unit, a coal-electricity cogeneration unit forms elements and a calculation model through the production cost of fresh water supplied by seawater desalination; dividing different power generation load working conditions, calculating a standard coal consumption difference value of a water supply working condition and a straight condensing working condition, and taking the ratio of the standard coal consumption difference value to the water supply as the average coal consumption for water supply; testing the main steam flow change under the pure condensation working condition and different water supply load working conditions, and calculating the water consumption increment for desalting caused by water supply to be used as the consumption of the desalted water for supplying water; introducing a coal-fired calorific value correction coefficient, and respectively calculating the power consumptions of the water supply system, the cold end, the steam turbine side and the boiler side to obtain the power consumption of the water supply plant; and counting the ratio of the dosage of the medicament under different water supply load working conditions to the water supply amount to be used as the medicament consumption for water supply. And determining the production cost of the external fresh water supply according to the economic relevant boundary parameters such as the price of power on the internet, the price of coal marked, the price of desalted water and the price of medicament.
Description
Technical Field
The invention belongs to the technical field of multi-effect distillation seawater desalination, and relates to a method and a system for determining the production cost of water production of a cogeneration unit.
Background
Fresh water resources in coastal areas are short, the cost of main flow south-to-north water transfer engineering is relatively high, supply is not sufficient, and seawater desalination can be used as an important guarantee for local water resources. According to the technical line division, the main commercial technologies are Reverse Osmosis (RO), multi-stage flash evaporation (MSF) and multi-effect distillation (MED).
RO technology is the process of counteracting natural osmosis by artificially applying pressure on the seawater side, causing water to migrate through a reverse osmosis membrane from the seawater side to the fresh water side.
In the MSF technology, seawater is heated in flash chambers, which are usually arranged in series, the temperature and pressure are gradually decreased with the number of stages, and the steam is cooled by the remaining concentrated seawater to form fresh water.
In the MED technology, evaporation occurs on the outer surface of the heating tube, seawater is heated by the compressed hot steam in the tube, each heating chamber is called an effect, the steam of the former effect is used as the heat source of the next effect, such heat integration arrangement can realize very high energy utilization efficiency of the whole system, in order to further improve the energy efficiency of the process, the MED unit can also be coupled with a steam recovery device, and the hot steam compression (TVC) and the mechanical steam compression (MVC) are the most common steam recovery device. Compared with the MSF technology, the MED technology has higher energy utilization efficiency and lower operating temperature, the corrosion and scaling risks in the desalination process are lower than those of the MSF, and the application performance scale and the prospect are higher than those of the MSF technology.
The MED system generally needs to provide heat energy and electric energy at the same time, has high energy consumption, is often coupled with facilities having waste gas heat sources, such as thermal power plants and chemical plants, and is coupled with a coal-electric unit, which is called cogeneration, and currently has many application performances.
The coal-electric machine set accurately evaluates the cost of the fresh water of the coal-electric machine set which leaves factory by transforming the fresh water supplied externally and purchasing the fresh water outside in municipal administration or enterprises, and is the key for reasonably and comprehensively planning the rights and interests of both parties of supply and demand and promoting the healthy development of the water supply market.
The gas supply cost is composed of production cost and non-production cost.
The non-production cost comprises depreciation, financial interest, newly added staff compensation and the like, and the existing calculation method is mature and scientific.
The production cost is composed of less power supply loss, coal consumption, service power consumption and demineralized water consumption caused by water supply.
The research on the desalination of seawater of a coal-electric machine set is more by overseas and overseas scholars, colleges and research institutions, but the research is more focused on heat source selection, process architecture, operation energy consumption analysis and the like (the typical summary is as follows), but the research on the production cost of fresh water supplied by the coal-electric machine set is only rarely reported in public at present.
Document 3, chenhaiping, lanjunjie, and the like, energy consumption characteristics of a seawater desalination system of a thermal power generating unit and thermal power cost analysis [ J ], a report of dynamic engineering, 2013 ", for example, a subcritical 600MW thermal power generating unit of a certain power plant and a seawater desalination system thereof, energy consumption characteristics of the thermal power generating unit and the seawater desalination system are researched based on a thermodynamic basic principle, an electricity-water heat consumption allocation model and a seawater desalination thermal power cost calculation model based on a quality unit are constructed, and sensitivity analysis is performed by taking unit operation load, a water generation ratio of the seawater desalination system, coal price, and the like as sensitive elements. The results show that: when the co-production steam extraction amount is constant, the cost of desalinating water is increased along with the reduction of the load of the unit; when the load is constant, the cost of desalinating water is reduced along with the increase of the steam extraction amount, but the change amplitude is not large; the total cost of seawater desalination water making is increased along with the increase of the unit price of standard coal, and the unit price of the standard coal has a large influence on the water making cost; the thermal cost of the fresh water is greatly influenced by the fresh water making ratio, and the thermal cost of the fresh water under different loads is sharply reduced along with the increase of the fresh water making ratio. The research uses a calculation method of a cogeneration unit about heat supply energy consumption for reference, provides a principle of water treatment of benefits, the treatment method is essentially still an equivalent heat drop analysis method, and the additional influence of seawater desalination steam extraction on the self-circulation energy consumption of the coal-electric unit is not taken into account; on the other hand, the research only accounts for the thermodynamic cost, does not account for electricity, water and the like, and has incomplete production cost composition.
Disclosure of Invention
The invention aims to solve the problems in the prior art and provides a method and a system for determining the production cost of water production of a water-electricity cogeneration unit.
In order to achieve the purpose, the invention adopts the following technical scheme to realize the purpose:
a method for determining the production cost of water production of a water-electricity cogeneration unit comprises the following steps:
determining the correlation characteristics of the power output and the water supply load of the water and power combined supply unit under the rated output condition of the boiler;
constructing a component and a calculation model of the production cost for water supply according to the correlation characteristics of the electric power output and the water supply load;
determining the little power generation loss caused by external supply fresh water in the constituent elements of the production cost for water supply;
determining the consumption of fire coal for water supply, the consumption of demineralized water and the consumption of a medicament for water supply in the components of the production cost for water supply by adopting a contrast method;
and classifying according to classes, and determining the service power consumption for supplying water to the water and electricity cogeneration unit in the constituent elements of the production cost for supplying water.
The invention is further improved in that:
the specific method for determining the correlation characteristics of the power output and the water supply load of the water and power combined supply unit under the rated output condition of the boiler comprises the following steps:
given a combined water and power generating unit, the boiler output is the main steam flow DmsCharacterised by a rated output of Dms0；
Output of low-temperature multi-effect seawater desalination preparation system is product fresh water mass flow QwCharacterizing, design rated output of Qw0；
Adjusting operation parameters to maintain boiler output Dms0And the mass flow of the fresh water of the product of the low-temperature multi-effect seawater desalination preparation system is respectively 0 and 0.2Q in the testw0、0.4Qw0、0.6Qw0、0.8Qw0And Qw0The unit electric output NgeObtaining the rated output D of the boiler through fittingms0Electric power output NgeAnd water supply load QwThe correlation characteristics of (2):
Nge＝f1(Dms0,Qw) (1)。
the concrete method for constructing the calculation model of the production cost for the water supply comprises the following steps:
the method comprises the following steps of constructing the components of the production cost, including: little power generation loss awCoal consumption cost bwDemineralized water consumption wwService power consumption ewAnd drug consumption dw；
Constructing a calculation model:
M＝x×aw×e+(1-x)bw×b+ww×c+ew×e+dw×d (2)
wherein x is a small power generation loss awWeight of (1-x) is the coal consumption cost bwThe weight of (c);
the unit price of standard coal is b, yuan/ton; the unit price of desalted water production is c, yuan/ton; the price of the power on the internet e, yuan/kWh; the unit price of the medicament is d, yuan/ton;
counting the number H of operating hours of the coal electric unit in the last natural yeartThe electric output is more than or equal to Nge,maxNumber of operating hours H0And calculating x:
the specific method for determining the loss of less power generation caused by the external supply fresh water comprises the following steps:
little power generation loss caused by external fresh water supplywThe unit fresh water causes the drop value of the electric output, and the loss a of the small power generation caused by the external supply fresh water is calculated according to the formula (1)w：
The specific method for determining the coal consumption, the desalted water consumption and the medicament consumption for water supply by adopting the contrast method comprises the following steps:
constructing a test working condition according to the distribution of the power generation load of the coal-electric machine set: 0.4Nge,0、0.5Nge,0、0.6Nge,0、0.7Nge,0And 0.8N ge,05 in total;
test water and electricity federationThe power output of the generator set is respectively 0.4Nge,0、0.5Nge,0、0.6Nge,0、0.7Nge,0And 0.8Nge,0Water production load Q under conditionsw,maxAnd fitting to obtain the maximum water supply load Q of the hydropower cogeneration unitw,maxAnd an electric force NgeThe correlation characteristics of (2):
Qw,max＝f2(Nge) (5)
aiming at the given working conditions of the 5 types of electrical loads, the coal quality is calculated according to the heat value q1Characterization, ambient temperature taRunning back pressure PcAnd an electric force NgeSetting boundary parameters, and adjusting the operation parameters of the water and electricity cogeneration unit to construct the following six operation conditions to supply water load QwThe characteristics that parameters of main steam and reheat steam of the unit are adjusted according to a set sliding pressure curve at the moment, and each working condition stably runs for 1 hour:
working condition 1: the power generation load NgeMaximum water supply load Q under the conditionw,max：Qw1＝Qw,max＝f2(Nge)，t/h；
Working condition 2: qw2＝0.8×Qw,max，t/h；
Working condition 3: qw3＝0.6×Qw,max，t/h；
Working condition 4: qw4＝0.4×Qw,max，t/h；
Working condition 5: qw5＝0.2×Qw,max，t/h；
Working condition 6: qw6Setting the working condition as 0, and operating under pure condensation condition;
according to the performance test rules of the boiler and the steam turbine, the efficiency eta of the constructed working condition boiler is testedbThe total heat consumption rate HR of the steam turbine and the total standard coal consumption B of 6 working conditions are calculated1、B2、B3、B4、B5、B6，t/h：
In the formula, hms、hrh、hrc、hgs、hzjAnd hgjRespectively calculating a main steam enthalpy value at an outlet of a boiler superheater, a main steam enthalpy value at an outlet of a boiler reheater, an inlet steam enthalpy value, a boiler inlet feed water enthalpy value, a boiler reheater and superheater desuperheating water enthalpy value, kJ/kg through field pressure and temperature measurement values;
eta b is the thermal efficiency of the boiler, different boilers are different, and the eta b is obtained according to field special tests:
ηb＝f3(Dms) (7)
ηpfor pipeline efficiency, a fixed value of 0.99 is taken;
calculating the average coal consumption b for water supply under the given working condition of each electric loadw1～bw5：
According to the electricity load conditions of the water and electricity cogeneration unit, the specific calculation method for weighted calculation of the average coal consumption for water supply of the water and electricity cogeneration unit comprises the following steps:
bw＝y1×bw1+y2×bw2+y3×bw1+y4×bw4+y5×bw5 (9)
wherein, y 1-y5Respectively 0.4N for the power output of the water and electricity cogeneration unitge,0、0.5Nge,0、0.6Nge,0、0.7Nge,0And 0.8Nge,0The weight of (c);
according to the electricity load conditions of the water and electricity cogeneration unit, the average desalted water consumption w for supplying water to the water and electricity cogeneration unit is calculated in a weighted modew：
ww＝y1×ww1+y2×ww2+y3×ww1+y4×ww4+y5×ww5
In the formula etaleakThe loss of working medium of steam-water thermodynamic cycle composed of boiler, steam turbine and heat regenerative system for water and electricity cogeneration unit is percentage of main steam flow, eta of different unitsleakThe values are different, and are 0.1-0.3%;
ww1～ww5respectively, an electric load of 0.4Nge,0、0.5Nge,0、0.6Nge,0、0.7Nge,0And 0.8Nge,0Corresponding water supply is consumed by average desalted water, t/t;
electric load of 0.4Nge,0、0.5Nge,0、0.6Nge,0、0.7Nge,0And 0.8Nge,0Each electric load working condition is represented by i, and the value is 1-5 respectively;
the fresh water and the medicament consumption of the external water supply of the water and power cogeneration unit under the test working conditions are counted, and the medicament consumption d for water supply in the constructed working conditions is calculatedw：
In the formula: j is the jth test condition of the ith electrical load segment.
D in the formula (6)m、Drh、Drc、Dgs、DzjAnd DgjRespectively representing main steam flow at an outlet of a boiler superheater, outlet of a boiler reheater, inlet steam flow, feed water flow at an inlet of the boiler, and desuperheating water flow of the boiler reheater and the superheater, wherein t/h is the flow rate of the boiler reheater and the superheater;
the above parameters are not independent of each other but follow a certain correlation:
Dms＝Dgs+Dgj (12)
Drh＝Drc+Dzj
Drc＝Dms-Dex1-Dex2-Dleak
in the formula, Dex1、Dex2And DleakRespectively performing 1-section steam extraction, 2-section steam extraction and shaft seal external leakage quantity of the high-pressure cylinder, t/h; wherein Dex1And Dex2Can be obtained by calculating the heat balance and the material balance of the high-pressure heater of the regenerative system corresponding to the 1-section extraction steam and the 2-section extraction steam, DleakIndicating main steam flow DmsAnd main steam pressure PmsThe binary function of (c):
Dleak＝f4(Dms,Pms) (13)。
y in the formula (9)1～y5The determination method comprises the following steps:
counting the number H of operating hours of the coal electric unit in the last natural yeartAccording to the electric output N of the coal electric machine setgeAccording to the following method, 0.4N is countedge,0、0.5Nge,0、0.6Nge,0、0.7Nge,0、0.8Nge,0Number of operating hours H1～H5；
Electric output Nge＜0.45Nge,0To score 0.4Nge,0Corresponding to H1；
Electric output of 0.45Nge,0≤Nge＜0.55Nge,0Score 0.5Nge,0Corresponding to H2；
Electric output of 0.55Nge,0≤Nge＜0.65Nge,0Score 0.6Nge,0Corresponding to H3；
Electric output of 0.65Nge,0≤Nge＜0.75Nge,0Score 0.7Nge,0Corresponding to H4；
Electric output of 0.75Nge,0≤NgeScore 0.8Nge,0Corresponding to H5；
Calculating y1～y5：
y1+y2+y3+y4+y5＝1 (14)。
H1+H2+H3+H4+H5＝Ht
The specific method for determining the service power consumption for supplying water to the cogeneration unit by classifying according to the classes comprises the following steps:
ew＝y1×ew1+y2×ew2+y3×ew1+y4×ew4+y5×ew5 (15)。
the specific method for determining the service power consumption for supplying water to the water and power cogeneration unit comprises the following steps:
the classifying by category includes classifying by water supply direct and indirect relevance:
equipment and system power consumption E only related to seawater desalination water supply systemdi；
The related power consumption of the pure water supply is recorded as E under 6 working conditionsdi-1、Edi-2、Edi-3、Edi-4、Edi-5And Edi-6In which Edi-60, the partial water supply consumes ediThe calculation method is as follows:
water supply is indirectly related, and water supply causes a decrease in power consumption:
Ecthe power consumption of cold-end system equipment is represented, and the power consumption of the cold-end system under 6 working conditions is respectively Ec-1、Ec-2、Ec-3、Ec-4、Ec-5And Ec-6The amount of electricity consumption reduction e of the cold end system caused by water supplyrc：
Water supply is indirectly related, and water supply causes increased power consumption:
characterised by the working medium flow, EtIndicating power consumption of auxiliary machinery on the steam turbine side, EbRepresenting the power consumption of the auxiliary machine on the boiler side;
the power consumption of 6 working conditions is respectively Et-1、Et-2、Et-3、Et-4、Et-5And Et-6Calculating the power consumption increment e of the auxiliary engine on the side of the steam turbine caused by external water supplyrt：
The power consumption of 6 working conditions is respectively Eb-1、Eb-2、Eb-3、Eb-4、Eb-5And Eb-6Introducing heat value correction coefficient of coal
Calculating the increase e of the power consumption of the side auxiliary machine of the boilerrb：
In the formula (I), the compound is shown in the specification,
the calculation method comprises the following steps:
in the formula, qiIs the calorific value of a certain coal;
calculating the power consumption e of the external supply of the desalted waterw：
ew＝edi-erc+ert+erb (21)。
A system for determining the production cost of water production of a water-electricity cogeneration unit comprises:
the correlation characteristic module is used for determining the correlation between the power output and the water supply load of the hydropower combined supply unit under the rated output condition of the boiler;
the calculation model module is used for calculating the production cost for water supply;
the power generation loss reduction module is used for determining that the external supply fresh water causes power generation loss reduction;
a comparison module for determining coal consumption, demineralized water consumption, and agent consumption for water supply;
the system comprises a classification module, and the classification module is used for determining service power consumption for water supply of the water and power cogeneration unit through specific power consumption equipment.
Compared with the prior art, the invention has the following beneficial effects:
the invention provides a method and a system for determining the production cost of water production of a water-electricity cogeneration unit, the method provided by the invention is in line with the practical production and strong operability, and the coal-electricity cogeneration unit constructs a production cost component and a calculation model of external fresh water supply through seawater desalination aiming at the specific water-electricity cogeneration unit; obtaining the ratio of the difference value between the electric output and the nameplate output caused by desalting the external fresh water through the seawater and the water supply quantity under the rated output condition of the coal-electric unit boiler through a field test as the low power generation cost for water supply; dividing different power generation load working conditions, testing the total heat consumption rate and the boiler efficiency of the steam turbine under the pure condensing working condition and different water supply load working conditions under the condition that boundary parameters such as coal quality, operation backpressure, power generation load and the like are the same, calculating a standard coal consumption difference value of the water supply working condition and the pure condensing working condition and a ratio of the standard coal consumption difference value to the water supply quantity, and taking the standard coal consumption difference value to the water supply quantity as the average coal consumption for water supply; testing the main steam flow change under the pure condensation working condition and different water supply load working conditions, and calculating the water consumption increment for desalting caused by water supply to be used as the consumption of the desalted water for supplying water; respectively recording the service power of the coal-electric power unit under the pure condensation working condition and the water supply working condition, respectively calculating the power consumptions of the water supply system, the cold end, the steam machine side and the boiler side according to three categories of reduction of the service power caused by a pure water supply system and water supply and increase of the service power caused by water supply, and respectively introducing a coal-fired heat value correction coefficient to obtain the power consumption of the water supply plant; and counting the ratio of the dosage of the medicament under different water supply load working conditions to the water supply amount to be used as the medicament consumption for water supply. And determining the production cost of the external fresh water supply according to the economic relevant boundary parameters such as the price of power on the internet, the price of coal marked, the price of desalted water and the price of medicament.
Drawings
In order to more clearly explain the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention, and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.
FIG. 1 is a schematic diagram of a cogeneration process employing multi-effect distillation technology;
fig. 2 is a flow schematic of the method for determining the production cost of the water produced by the cogeneration unit.
Wherein: 1-a boiler; 2-high pressure cylinder; 3-a medium pressure cylinder; 4-low pressure cylinder; 5-a generator; 6-a condenser; 7-a condensate pump; 8-low pressure heater group; 9-a deaerator; 10-a feed pump; 11-high pressure heater group; 12-a raw seawater pump; 13-low-temperature multi-effect seawater desalination device; 14-fresh water storage tank; 15-fresh water supply pump; 16-water ring vacuum pump; 17-booster pump.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.
Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.
In the description of the embodiments of the present invention, it should be noted that if the terms "upper", "lower", "horizontal", "inner", etc. are used for indicating the orientation or positional relationship based on the orientation or positional relationship shown in the drawings or the orientation or positional relationship which is usually arranged when the product of the present invention is used, the description is merely for convenience and simplicity, and the indication or suggestion that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and thus, cannot be understood as limiting the present invention. Furthermore, the terms "first," "second," and the like are used merely to distinguish one description from another, and are not to be construed as indicating or implying relative importance.
Furthermore, the term "horizontal", if present, does not mean that the component is required to be absolutely horizontal, but may be slightly inclined. For example, "horizontal" merely means that the direction is more horizontal than "vertical" and does not mean that the structure must be perfectly horizontal, but may be slightly inclined.
In the description of the embodiments of the present invention, it should be further noted that unless otherwise explicitly stated or limited, the terms "disposed," "mounted," "connected," and "connected" should be interpreted broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.
The invention is described in further detail below with reference to the accompanying drawings:
referring to fig. 1, the embodiment of the invention discloses a water and power cogeneration structure schematic diagram adopting a multi-effect distillation technology, and a steam-water circulation module for power generation of a coal-electric machine set comprises: steam at the outlet of a superheater of the boiler 1 enters a high-pressure cylinder 2 to do work, exhaust steam enters a reheater of the boiler 1 to be subjected to secondary temperature rise and then enters an intermediate-pressure cylinder 3 to do work, the exhaust steam enters a low-pressure cylinder 4 to do work, and the exhaust steam enters a condenser 6 to be condensed. The high pressure cylinder 2, the intermediate pressure cylinder 3 and the low pressure cylinder 4 are coaxially connected and drive a generator 5 to generate electricity together. After being pressurized by a condensate pump 7, the condensate at the outlet of the condenser 5 sequentially rises in temperature and pressure by a low-pressure heater group 8, a deaerator 9, a water feed pump 10 and a high-pressure heater group 11, and then enters the boiler 1 to complete thermodynamic cycle.
A low-temperature multi-effect seawater desalination system is additionally arranged, the original seawater is pressurized by an original seawater water taking pump 12, enters a low-temperature multi-effect seawater desalination device 13, is divided into two paths after being driven by exhaust steam in a coal-electric machine set, one path is fresh water, enters a fresh water storage tank 14 as a product, and is driven by a fresh water supply pump 15 to be supplied outwards; one path is high-temperature strong brine discharge. The electric water ring vacuum pump 15 pumps out non-condensable gas in the low-temperature multi-effect seawater desalination device 16 so as to maintain the heat exchange effect of the low-temperature multi-effect seawater desalination device. The drained water of the extracted steam in the coal electric machine set after the heat release of the low-temperature multi-effect seawater desalination device 16 is returned to the thermodynamic system of the coal electric machine set through the booster pump 17.
Referring to fig. 2, a method for determining the production cost of water production of a cogeneration unit disclosed in the embodiment of the present invention:
step 1: determining that the water and electricity combined supply unit is in the potElectric output N under rated output of furnacegeAnd water supply load QwAnd (6) associating the characteristics.
Given a combined water and power generating unit, the boiler output is the main steam flow DmsCharacterised by a rated output of Dms0。
Output of low-temperature multi-effect seawater desalination preparation system is product fresh water mass flow QwCharacterizing, design rated output of Qw0。
The technical method of field test is adopted, and the operation parameters are adjusted to maintain the boiler output Dms0And the mass flow of the fresh water of the product of the low-temperature multi-effect seawater desalination preparation system is respectively 0 and 0.2Q in the testw0、0.4Qw0、0.6Qw0、0.8Qw0And Qw0The unit electric output NgeObtaining the rated output D of the boiler through fittingms0Electric power output NgeAnd water supply load QwThe correlation property is shown in formula (1).
Nge＝f1(Dms0,Qw) (1)。
Step 2: and constructing a water supply production cost M calculation model.
The coal-electricity unit supplies fresh water while supplying power to the outside by additionally arranging a low-temperature multi-effect seawater desalination system, but the power grid still carries out electric load scheduling according to the state of the pure condensing unit, and the water-electricity cogeneration unit supplies water Q to the outsidewCausing a maximum electrical output Nge,maxLower than the nameplate value Nge,0And the power grid dispatching can not be met, and the small power generation loss a in the periodw(MW/t) is considered to be one of the components of the production cost M for water supply.
In the presence of an electric force Nge,maxThe coal-electric machine set can be adjusted by the output of the boiler to meet the requirements of the power grid on the electric load and the park on the air load, and one of the factors of the production cost M for supplying air is the coal consumption cost bw(t/t)。
In addition to this, the constituent factor is the demineralized water consumption ww(t/t) service Power consumption ew(MW/t), drug consumption dw(t/t) is shown in formula (2).
M＝x×aw×e+(1-x)bw×b+ww×c+ew×e+dw×d (2)
Wherein x is a small power generation loss awWeight of (1-x) is the coal consumption cost bwThe weight of (c).
The unit price of standard coal is b, yuan/ton; the unit price of desalted water production is c, yuan/ton; yuan per ton; the price of the power on the internet e, yuan/kWh; the dosage is d, yuan/ton.
Counting the number H of operating hours of the coal electric unit in the last natural yeartThe electric output is more than or equal to Nge,maxNumber of operating hours H0X is calculated according to equation (3).
And step 3: determining the loss of a little power generation caused by external fresh water supplyw
Little power generation loss caused by external fresh water supplywThe unit fresh water causes the drop value of the electric output, and the loss a of the small power generation caused by the external supply fresh water is calculated according to the formula (1)wSee formula (4).
And 4, step 4: determining the coal consumption b for water supply by comparison methodwDemineralized water consumption ww。
(1) Determining maximum air supply load Q of water-electricity cogeneration unitw,maxAnd an electric force NgeThe correlation characteristic of (2).
The power output of the test water and electricity cogeneration unit is respectively 0.4Nge,0、0.5Nge,0、0.6Nge,0、0.7Nge,0And 0.8Nge,0Water production load Q under conditionsw,maxAnd fitting to obtain the maximum water supply load Q of the hydropower cogeneration unitw,maxAnd electrical output NgeSee equation (5).
Qw,max＝f2(Nge) (5)
(2) Constructing test conditions
The water production performance of low-temperature multi-effect seawater desalination is greatly influenced by heat source steam parameters, the heat source steam parameters are influenced by the electrical load of the coal-electric machine set, and the heat source steam parameters are adjusted by throttling through a medium-low pressure communicating pipe regulating valve in a low electrical load section.
Firstly, establishing a test working condition according to the distribution of the power generation load of the coal-electric machine set: 0.4Nge,0、0.5Nge,0、0.6Nge,0、0.7Nge,0And 0.8Nge,0There are 5 major classes.
Coal quality (in terms of heat value q) under given working conditions of the 5 major types of electric loads1Characterization), ambient air temperature taRunning back pressure PcAnd an electric output NgeSetting parameters of an equilateral boundary, and adjusting the operation parameters of the water and electricity cogeneration unit to construct the following six operation conditions so as to supply water load QwAnd (5) characterizing. At the moment, the parameters of main steam and reheat steam of the unit are adjusted according to a set sliding pressure curve, and each working condition stably runs for 1 hour.
Working condition 2: qw2＝0.8×Qw,max，t/h；
Working condition 3: qw3＝0.6×Qw,max，t/h；
Working condition 4: qw4＝0.4×Qw,max，t/h；
Working condition 5: qw5＝0.2×Qw,max，t/h；
Working condition 6: qw6Setting the working condition as 0, and operating under pure condensation condition;
(3) according to the performance test rules of the boiler and the steam turbine, the efficiency eta of the boiler under the six working conditions is testedbAnd calculating the total standard coal consumption B of the 6 groups of working conditions by using the total heat consumption rate HR of the steam turbine1、B2、B3、B4、B5、B6T/h, see formula (6).
In the formula, hms、hrh、hrc、hgs、hzjAnd hgjThe enthalpy values of main steam at an outlet of a boiler superheater, steam at an outlet of a boiler reheater and an inlet of the boiler, the enthalpy value of feed water at an inlet of the boiler, and the enthalpy values of desuperheating water of the boiler reheater and the superheater are kJ/kg respectively. Can be calculated from in situ pressure and temperature measurements.
ηbThe thermal efficiency of the boiler is shown in formula (7), and different boilers are different and need to be obtained according to field special tests.
ηb＝f3(Dms) (7)
ηpFor pipeline efficiency, a fixed value of 0.99 was taken.
Dm、Drh、Drc、Dgs、DzjAnd DgjThe main steam flow at the outlet of the boiler superheater, the steam flow at the outlet and the inlet of the boiler reheater, the feed water flow at the inlet of the boiler, and the desuperheating water flow of the boiler reheater and the superheater are respectively t/h. The above parameters are not independent of each other, but follow a certain relationship, see equation (12).
Dms＝Dgs+Dgj (12)
Drh＝Drc+Dzj
Drc＝Dms-Dex1-Dex2-Dleak
In the formula, Dex1、Dex2And DleakRespectively 1-section steam extraction, 2-section steam extraction and shaft seal external leakage amount of the high-pressure cylinder, t/h. Wherein Dex1And Dex2Can be obtained by calculating the heat balance and the material balance of the high-pressure heater of the regenerative system corresponding to the extraction steam of the 1 section and the extraction steam of the 2 section, DleakIs the main steam flow DmsAnd main steam pressure PmsThe binary function of (a) is given by the steam turbine manufacturer, see equation (13).
Dleak＝f4(Dms,Pms) (13)。
(4) According to the calculated average coal consumption b for water supply under the given working condition of each electric loadw1～bw5(respective characterization of the Electrical load 0.4Nge,0、0.5Nge,0、0.6Nge,0、0.7Nge,0And 0.8Nge,0Corresponding average coal consumption for water supply), see formula (8)
(5) According to the electricity load conditions of the water and electricity cogeneration unit, the average coal consumption b for water supply of the water and electricity cogeneration unit is calculated in a weighted modewSee type (9)
bw＝y1×bw1+y2×bw2+y3×bw1+y4×bw4+y5×bw5 (9)
In the formula, y1～y5Respectively 0.4N for the power output of the water and electricity cogeneration unitge,0、0.5Nge,0、0.6Nge,0、0.7Nge,0And 0.8Nge,0The weight of (2) is determined as follows.
Counting the number H of operating hours of the coal electric unit in the last natural yeartAccording to the electric output N of the coal electric machine setgeAccording to the following method, 0.4N is countedge,0、0.5Nge,0、0.6Nge,0、0.7Nge,0、0.8Nge,0Number of operating hours H1～H5。
Electric output Nge＜0.45Nge,0To score 0.4Nge,0Corresponding to H1；
Electric output of 0.45Nge,0≤Nge＜0.55Nge,0Score 0.5Nge,0Corresponding to H2；
Electric output of 0.55Nge,0≤Nge＜0.65Nge,0Score 0.6Nge,0Corresponding to H3；
Electric output of 0.65Nge,0≤Nge＜0.75Nge,0Score 0.7Nge,0Corresponding to H4；
Electric output of 0.75Nge,0≤NgeScore 0.8Nge,0Corresponding to H5；
Calculating y from equation (14)1～y5。
y1+y2+y3+y4+y5＝1 (14)。
H1+H2+H3+H4+H5＝Ht
(6) Calculating the demineralized water consumption ww for water supply
The reason why the consumption of demineralized water is increased due to the external supply of fresh water in the water and power cogeneration unit is as follows: the external leakage of a system working medium is increased due to the fact that the external industrial air causes the increase of the flow of water supply and main steam in the steam-water circulation of the cogeneration unit, and in order to maintain the balance of the steam-water circulation working medium of the cogeneration unit, demineralized water with the external leakage amount needs to be added into a condenser. According to the electricity load conditions of the water and electricity cogeneration unit, the water and electricity cogeneration is calculated in a weighting wayAverage coal consumption w for unit water supplywSee type (10)
ww＝y1×ww1+y2×ww2+y3×ww1+y4×ww4+y5×ww5
In the formula etaleakThe heat recovery system is a steam-water thermodynamic cycle consisting of a boiler, a steam turbine and a regenerative system, and the loss of working media accounts for the proportion of the main steam flow due to running, overflowing, dripping, leakage and the like. Eta of different units with different tightness degree of equipment and steam-water pipeline valvesleakThe values are different, and are generally 0.1-0.3%;
ww1～ww5respectively, an electric load of 0.4Nge,0、0.5Nge,0、0.6Nge,0、0.7Nge,0And 0.8Nge,0Corresponding water supply is consumed by average desalted water, t/t;
electric load of 0.4Nge,0、0.5Nge,0、0.6Nge,0、0.7Nge,0And 0.8Nge,0Each electric load working condition is represented by i, and the value is 1-5 respectively;
and 5: and (4) determining service power consumption ew for water supply of the water and power cogeneration unit according to class division.
According to 0.4Nge,0、0.5Nge,0、0.6Nge,0、0.7Nge,0And 0.8Nge,0Obtaining service power consumption e for supplying water to the hydropower cogeneration unit according to the following steps under five electric load working conditionsw1～ew5And calculating the average service power consumption e for supplying water to the water-electricity cogeneration unit in a weighted mannerwSee formula (15).
ew＝y1×ew1+y2×ew2+y3×ew1+y4×ew4+y5×ew5 (15)。
(1) The configuration of the power consuming equipment is clarified and classified according to the direct and indirect relevance of the water supply as follows:
1) equipment and system power consumption E only related to seawater desalination water supply systemdi。
The equipment related to the seawater desalination water supply system mainly comprises an original seawater water taking pump 12, a fresh water supply pump 15, a water ring vacuum pump 16, a booster pump 17, the power consumption of an original seawater dosing system and the like, and the power consumption related to pure water supply of 6 working conditions is recorded as Edi-1、Edi-2、Edi-3、Edi-4、Edi-5And Edi-6In which Edi-60, the partial water supply consumes ediSee equation (16).
2) Water supply is indirectly related and causes a reduction in power consumption.
The coal-fired water and electricity cogeneration unit supplies desalinated water to the outside industry, the loss of a cold source is reduced, and the auxiliary power consumption of a cold end system is reduced under the condition of unchanged operation backpressure. Cold end system equipment power consumption EcThis can be classified as such. The system is divided according to the form of a cold end system, the direct air cooling unit is an air cooling fan, and the wet cooling and indirect air cooling units are circulating water pumps. The power consumption of the cold end system under 6 working conditions is respectively Ec-1、Ec-2、Ec-3、Ec-4、Ec-5、Ec-6The amount of electricity consumption reduction e of the cold end system caused by water supplyrcChinese character of ' calculating ' (' 17)
3) Water supply is indirectly related and causes increased power consumption.
The coal-fired water and electricity cogeneration unit can desalt water externally, and the flow of working media such as condensed water, feed water, main steam, coal consumption, flue gas, wind, dust and the like is correspondingly increased under the condition of isoelectric power. Can be divided into a steam engine side E according to working medium flowtAnd boiler side EbTwo major categories.
Power consumption E of side auxiliary machine of steam enginetMainly comprises an electric work water feed pump set, a condensate pump and the like, and the power consumption of 6 working conditions is respectively Et-1、Et-2、Et-3、Et-4、Et-5、Et-6And the relation between the power consumption and the water supply of the steam turbine side auxiliary machine of the hydropower cogeneration unit can be determined by fitting according to 6 test working conditions. Increase e of power consumption of auxiliary machine on steam turbine side caused by external water supplyrtSee equation (18).
Boiler side auxiliary machine power consumption EbMainly comprises a draught fan, a blower, a primary fan, a coal mill and related equipment of a dust removal, desulfurization and denitrification system, wherein the power consumption of 6 working conditions is E respectivelyb-1、Eb-2、Eb-3、Eb-4、Eb-5、Eb-6The relationship between the power consumption and the water supply of the auxiliary machinery on the boiler side of the water-power cogeneration unit is also influenced by the quality of coal (represented by a heat value). In order to ensure the universality of the invention, a coal-fired heat value correction coefficient is introduced
Calculating the power consumption increment e of auxiliary machinery at the boiler side caused by water supply according to the formula (20)rbSee equation (19).
In the formula, qiIs the calorific value of a certain coal.
(2) Calculating the power consumption e of the external supply of the desalted waterwCalculated according to equation (21).
ew＝edi-erc+ert+erb (21)
Step 6: determining water supply medicament consumption dw of water and electricity cogeneration unit
Counting the fresh water supply amount and the medicament consumption amount of the external water supply and the medicament consumption amount of the water-electricity cogeneration unit under 30 groups of test working conditions in the step 4, and calculating the medicament consumption d for water supply according to the formula (11)w。
In the formula: j is the jth test condition of the ith electrical load segment.
The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes will occur to those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (10)
1. A method for determining the production cost of water production of a water-electricity cogeneration unit is characterized by comprising the following steps:
determining the correlation characteristics of the power output and the water supply load of the water and power combined supply unit under the rated output condition of the boiler;
constructing a component and a calculation model of the production cost for water supply according to the correlation characteristics of the electric power output and the water supply load;
determining the little power generation loss caused by external supply fresh water in the constituent elements of the production cost for water supply;
determining the consumption of fire coal for water supply, the consumption of demineralized water and the consumption of a medicament for water supply in the components of the production cost for water supply by adopting a contrast method;
and classifying according to classes, and determining the service power consumption for supplying water to the water and electricity cogeneration unit in the constituent elements of the production cost for supplying water.
2. The method for determining the production cost of the water-making water of the water-electricity cogeneration unit according to claim 1, wherein the specific method for determining the correlation characteristics of the electric output and the water supply load of the water-electricity cogeneration unit under the rated output condition of the boiler comprises the following steps:
given a combined water and power generating unit, the boiler output is the main steam flow DmsCharacterised by a rated output of Dms0；
Output of low-temperature multi-effect seawater desalination preparation system is product fresh water mass flow QwCharacterizing, design rated output of Qw0；
Adjusting operation parameters to maintain boiler output Dms0And the mass flow of the fresh water of the product of the low-temperature multi-effect seawater desalination preparation system is respectively 0 and 0.2Q in the testw0、0.4Qw0、0.6Qw0、0.8Qw0And Qw0The unit electric output NgeObtaining the rated output D of the boiler through fittingms0Electric power output NgeAnd water supply load QwThe correlation characteristics of (2):
Nge＝f1(Dms0,Qw) (1)。
3. the method for determining the production cost of the water production of the cogeneration unit according to claim 1, wherein the concrete method for constructing the calculation model of the production cost for water supply comprises the following steps:
the method comprises the following steps of constructing the components of the production cost, including: little power generation loss awCoal consumption cost bwDemineralized water consumption wwService power consumption ewAnd drug consumption dw；
Constructing a calculation model:
M＝x×aw×e+(1-x)bw×b+ww×c+ew×e+dw×d (2)
wherein x is a small power generation loss awWeight of (1-x) is the coal consumption cost bwThe weight of (c);
the unit price of standard coal is b, yuan/ton; the unit price of desalted water production is c, yuan/ton; the price of the power on the internet e, yuan/kWh; the unit price of the medicament is d, yuan/ton;
counting the number H of operating hours of the coal electric unit in the last natural yeartThe electric output is more than or equal to Nge,maxFortune ofNumber of hours of travel H0And calculating x:
4. the method for determining the production cost of the water produced by the cogeneration unit according to claim 1, wherein the specific method for determining the loss of less power generation caused by the externally supplied fresh water comprises the following steps:
little power generation loss caused by external fresh water supplywThe unit fresh water causes the drop value of the electric output, and the loss a of the small power generation caused by the external supply fresh water is calculated according to the formula (1)w：
5. The method for determining the production cost of the water production of the cogeneration unit according to claim 1, wherein the specific method for determining the consumption of the coal for water supply, the consumption of the desalted water and the consumption of the chemical for water supply by using the comparison method comprises the following steps:
constructing a test working condition according to the distribution of the power generation load of the coal-electric machine set: 0.4Nge,0、0.5Nge,0、0.6Nge,0、0.7Nge,0And 0.8Nge,05 in total;
the power output of the test water and electricity cogeneration unit is respectively 0.4Nge,0、0.5Nge,0、0.6Nge,0、0.7Nge,0And 0.8Nge,0Water production load Q under conditionsw,maxAnd fitting to obtain the maximum water supply load Q of the hydropower cogeneration unitw,maxAnd an electric force NgeThe correlation characteristics of (2):
Qw,max＝f2(Nge) (5)
aiming at the given working conditions of the 5 types of electrical loads, the coal quality is calculated according to the heat value q1Characterization, ambient temperature taRunning back pressure PcAnd an electricity outletForce NgeSetting boundary parameters, and adjusting the operation parameters of the water and electricity cogeneration unit to construct the following six operation conditions to supply water load QwThe characteristics that parameters of main steam and reheat steam of the unit are adjusted according to a set sliding pressure curve at the moment, and each working condition stably runs for 1 hour:
working condition 1: the power generation load NgeMaximum water supply load Q under the conditionw,max：Qw1＝Qw,max＝f2(Nge)，t/h；
Working condition 2: qw2＝0.8×Qw,max，t/h；
Working condition 3: qw3＝0.6×Qw,max，t/h；
Working condition 4: qw4＝0.4×Qw,max，t/h；
Working condition 5: qw5＝0.2×Qw,max，t/h；
Working condition 6: qw6Setting the working condition as 0, and operating under pure condensation condition;
according to the performance test rules of the boiler and the steam turbine, the efficiency eta of the constructed working condition boiler is testedbThe total heat consumption rate HR of the steam turbine and the total standard coal consumption B of 6 working conditions are calculated1、B2、B3、B4、B5、B6，t/h：
In the formula, hms、hrh、hrc、hgs、hzjAnd hgjRespectively calculating a main steam enthalpy value at an outlet of a boiler superheater, a main steam enthalpy value at an outlet of a boiler reheater, an inlet steam enthalpy value, a boiler inlet feed water enthalpy value, a boiler reheater and superheater desuperheating water enthalpy value, kJ/kg through field pressure and temperature measurement values;
ηbfor the boiler thermal efficiency, different boilers are different, and the thermal efficiency needs to be obtained according to field special tests:
ηb＝f3(Dms) (7)
ηpfor pipeline efficiency, a fixed value of 0.99 is taken;
calculating the average coal consumption b for water supply under the given working condition of each electric loadw1～bw5：
According to the electricity load conditions of the water and electricity cogeneration unit, the specific calculation method for weighted calculation of the average coal consumption for water supply of the water and electricity cogeneration unit comprises the following steps:
bw＝y1×bw1+y2×bw2+y3×bw1+y4×bw4+y5×bw5 (9)
in the formula, y1～y5Respectively 0.4N for the power output of the water and electricity cogeneration unitge,0、0.5Nge,0、0.6Nge,0、0.7Nge,0And 0.8Nge,0The weight of (c);
according to the electricity load conditions of the water and electricity cogeneration unit, the average desalted water consumption w for supplying water to the water and electricity cogeneration unit is calculated in a weighted modew：
ww＝y1×ww1+y2×ww2+y3×ww1+y4×ww4+y5×ww5
In the formula etaleakThe loss of working medium of steam-water thermodynamic cycle composed of boiler, steam turbine and heat regenerative system for water and electricity cogeneration unit is percentage of main steam flow, eta of different unitsleakThe values are different, and are 0.1-0.3%;
ww1～ww5respectively, an electric load of 0.4Nge,0、0.5Nge,0、0.6Nge,0、0.7Nge,0And 0.8Nge,0Corresponding water supply is consumed by average desalted water, t/t;
electric load of 0.4Nge,0、0.5Nge,0、0.6Nge,0、0.7Nge,0And 0.8Nge,0Each electric load working condition is represented by i, and the value is 1-5 respectively;
the fresh water and the medicament consumption of the external water supply of the water and power cogeneration unit under the test working conditions are counted, and the medicament consumption d for water supply in the constructed working conditions is calculatedw：
In the formula: j is the jth test condition of the ith electrical load segment.
6. The method for determining the production cost of water produced by a cogeneration unit according to claim 5, wherein D in the formula (6)m、Drh、Drc、Dgs、DzjAnd DgjRespectively representing main steam flow at an outlet of a boiler superheater, outlet of a boiler reheater, inlet steam flow, feed water flow at an inlet of the boiler, and desuperheating water flow of the boiler reheater and the superheater, wherein t/h is the flow rate of the boiler reheater and the superheater;
the above parameters are not independent of each other but follow a certain correlation:
Dms＝Dgs+Dgj (12)
Drh＝Drc+Dzj
Drc＝Dms-Dex1-Dex2-Dleak
in the formula, Dex1、Dex2And DleakRespectively performing 1-section steam extraction, 2-section steam extraction and shaft seal external leakage quantity of the high-pressure cylinder, t/h; wherein Dex1And Dex2Can be obtained by calculating the heat balance and the material balance of the high-pressure heater of the regenerative system corresponding to the 1-section extraction steam and the 2-section extraction steam, DleakIndicating main steam flow DmsAnd main steam pressure PmsThe binary function of (c):
Dleak＝f4(Dms,Pms) (13)。
7. method for determining the production cost of water produced by cogeneration unit according to claim 6, wherein y in said formula (9)1～y5The determination method comprises the following steps:
counting the number H of operating hours of the coal electric unit in the last natural yeartAccording to the electric output N of the coal electric machine setgeAccording to the following method, 0.4N is countedge,0、0.5Nge,0、0.6Nge,0、0.7Nge,0、0.8Nge,0Number of operating hours H1～H5；
Electric output Nge＜0.45Nge,0To score 0.4Nge,0Corresponding to H1；
Electric output of 0.45Nge,0≤Nge＜0.55Nge,0Score 0.5Nge,0Corresponding to H2；
Electric output of 0.55Nge,0≤Nge＜0.65Nge,0Score 0.6Nge,0Corresponding to H3；
Electric output of 0.65Nge,0≤Nge＜0.75Nge,0Score 0.7Nge,0Corresponding to H4；
Electric output of 0.75Nge,0≤NgeScore 0.8Nge,0Corresponding to H5；
Calculating y1～y5：
y1+y2+y3+y4+y5＝1 (14)。
H1+H2+H3+H4+H5＝Ht
8. The method for determining the production cost of the water produced by the cogeneration unit according to claim 7, wherein the specific method for determining the service power consumption for the water supply of the cogeneration unit by classifying according to the categories is as follows:
ew＝y1×ew1+y2×ew2+y3×ew1+y4×ew4+y5×ew5 (15)。
9. the method for determining the production cost of the water production of the cogeneration unit according to claim 8, wherein the specific method for determining the consumption of the service power for supplying the water to the cogeneration unit is as follows:
the classifying by category includes classifying by water supply direct and indirect relevance:
equipment and system power consumption E only related to seawater desalination water supply systemdi；
The related power consumption of the pure water supply is recorded as E under 6 working conditionsdi-1、Edi-2、Edi-3、Edi-4、Edi-5And Edi-6In which Edi-60, the partial water supply consumes ediComputing methodComprises the following steps:
water supply is indirectly related, and water supply causes a decrease in power consumption:
Ecthe power consumption of cold-end system equipment is represented, and the power consumption of the cold-end system under 6 working conditions is respectively Ec-1、Ec-2、Ec-3、Ec-4、Ec-5And Ec-6The amount of electricity consumption reduction e of the cold end system caused by water supplyrc：
Water supply is indirectly related, and water supply causes increased power consumption:
characterised by the working medium flow, EtIndicating power consumption of auxiliary machinery on the steam turbine side, EbRepresenting the power consumption of the auxiliary machine on the boiler side;
the power consumption of 6 working conditions is respectively Et-1、Et-2、Et-3、Et-4、Et-5And Et-6Calculating the power consumption increment e of the auxiliary engine on the side of the steam turbine caused by external water supplyrt：
The power consumption of 6 working conditions is respectively Eb-1、Eb-2、Eb-3、Eb-4、Eb-5And Eb-6Introducing heat value correction coefficient of coal
Calculating the increase e of the power consumption of the side auxiliary machine of the boilerrb：
In the formula (I), the compound is shown in the specification,
the calculation method comprises the following steps:
in the formula, qiIs the calorific value of a certain coal;
calculating the power consumption e of the external supply of the desalted waterw：
ew＝edi-erc+ert+erb (21)。
10. A system for determining the production cost of water production of a water-electricity cogeneration unit is characterized by comprising:
the correlation characteristic module is used for determining the correlation between the power output and the water supply load of the hydropower combined supply unit under the rated output condition of the boiler;
the calculation model module is used for calculating the production cost for water supply;
the power generation loss reduction module is used for determining that the external supply fresh water causes power generation loss reduction;
a comparison module for determining coal consumption, demineralized water consumption, and agent consumption for water supply;
the system comprises a classification module, and the classification module is used for determining service power consumption for water supply of the water and power cogeneration unit through specific power consumption equipment.
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