Power generation system optimal control method
Technical field
The present invention relates to electricity generation system, more particularly, to by the use of unstable thermal source such as underground heat or waste heat as heat supply come
The electricity generation system in source.
Background technology
As fossil energy increasingly depleted, earth environment constantly deteriorate, energy security is increasingly valued by people.Energy
The utilization in source is related to a national economic lifeline and social safety, and the basic development strategy worlds of country are risen to already
Each state all pays much attention to effective utilization of the energy, and China's energy utilization rate is only 33% or so, lower than developed country by about 10%.
A low major reason of China's energy utilization rate is that the energy is not reaching to cascade utilization, substantial amounts of middle low-temperature energy sources
It is not fully used, therefore the utilization of low-temperature energy sources is the key measure for improving efficiency of energy utilization in raising.Middle low temperature
Thermal source mainly includes two large divisions:First is the waste heat discharged in industrial production, such as metallurgy, chemical industry, building materials, machinery, electric power
Exhaust etc. the various smelting furnaces in industry, heating furnace, internal combustion engine and boiler is discharged fume, because China's industrial energy consumption accounts for the whole nation
2/3rds of total energy consumption, and more than 50% is discharged in the form of middle low-temperature waste heat, therefore recycle this partial heat tool
There is huge energy-saving potential;Part II is low temperature regenerative resource in solar energy, underground heat etc., with China's energy resource structure
Adjustment, the ratio shared by regenerative resource will be increasing.Strengthen the utilization to low-temperature heat source in these, will reduce to fossil
The consumption of the energy, reaches the effect of energy-saving and emission-reduction.
The technology that low temperature heat energy generates electricity in utilization is mainly based upon the heat power generating system of Rankine cycle.Double-work medium circulation hair
Electric system is a kind of main middle low-temperature thermal power generating system.The characteristics of double-work medium power generation technology is hot water with electricity generation system not
Directly contact, using a kind of lower boiling medium, such as normal butane, iso-butane, chloroethanes, ammonia and carbon dioxide are used as circulation industrial
The heat of hot water is transmitted to certain low boiling point working medium by matter, is generated electricity by low boiling point working medium pushing turbine.
In double-work medium circulating generation, hot water is only used as thermal source, and itself is not participated directly in thermodynamic cycle.
First, the hot water from middle low-temperature heat source flows through surface-type evaporator with the low boiling point working medium in heating evaporation device.Low boiling is situated between
Matter is absorbed heat in evaporator, is changed into the steam with certain pressure, and pushing turbine simultaneously drives electrical power generators.From steam turbine row
The gas gone out, condenses into liquid within the condenser, and liquid is sent into heat exchanger with pump, and evaporation of absorbing heat again becomes gas, so
Go round and begin again, the heat of hot water is constantly transmitted to low boiling point working medium and continuously generated electricity.
Shortcoming using underground heat or waste heat as the electricity generation system of middle low-temperature heat source is the unstability of thermal source, due to
Thermal source unstable for example with multiple power generation cycles, can adapt to big, it is necessary to make specific design to TRT
The heat from heat source of amplitude variation.CN102691541B patent of invention, it is proposed that one kind has multiple power generation cycles, wherein one
Heating medium block valve and cooling medium block valve is set in power generation cycle, thus allow for variation according to thermal source and incite somebody to action
Heat is rightly distributed to the generating of multiple thermal cycles.But, for specific power generation cycle, started or stopped needs
Regular hour, and frequent starting and stopping power generation cycle returning its operating efficiency of influence and systematic function.
The content of the invention
The invention provides a kind of electricity generation system of optimization and its control method, in the case where heat from heat source changes, energy
Enough reduce the switching frequency of specific power generation cycle in the technical scheme of CN102691541B inventions, so as to improve systematic function.
As one aspect of the present invention there is provided a kind of electricity generation system, including the first power generation cycle, the second power generation cycle with
And controller;First power generation cycle, the second power generation cycle are exported using heating medium feeding pipe in parallel, heating medium
Pipeline, cooling medium feeding pipe and cooling medium output pipe;The controller is used for according to heating medium and first
The working condition of power generation cycle and the second power generation cycle, controls the operation of first power generation cycle and the second power generation cycle,
First power generation cycle is main electricity generation system, and it has pressure turbine and middle-pressure turbine;Second power generation cycle be from
Electricity generation system, it has pressure turbine;The controller generates electricity according to heating medium and the first power generation cycle and second and followed
The working condition of ring, controls at least one startup in the first power generation cycle mesohigh turbine and middle-pressure turbine,
And control the pressure turbine of second power generation cycle to start or close.
It is preferred that, the heating medium feeding pipe will heat medium and be transported to the first generating by branch road respectively from main line
Circulation and the evaporator of the second power generation cycle, so that the work heated in the first power generation cycle and the second power generation cycle is situated between
Matter, the working media drives the turbine movements of the first power generation cycle and the second power generation cycle, so as to drive the first generating
The generator of circulation and the second power generation cycle is generated electricity;The heating exported from the first power generation cycle and the second power generation cycle
Medium, converges to the main line discharge of heating medium output pipe.
It is preferred that, cooling medium is transported to the first generating by the cooling medium feeding pipe by branch road respectively from main line
Circulation and the condenser of the second power generation cycle, cool down the work discharged from the first power generation cycle and the second power generation cycle turbine
Make medium;The cooling medium exported from the first generating ring and the second power generation cycle, converges to the dry of cooling medium output pipe
Discharge on road.
It is preferred that, the pressure turbine and middle-pressure turbine of first power generation cycle pass through rotating shaft and generator coupling
Close, so as to drive generator to be generated electricity.
It is preferred that, the export pipeline of the first power generation cycle evaporator operation medium is divided into two-way, wherein passing through all the way
First valve is communicated with the working medium inlet of the pressure turbine, passes through the second valve and medium pressure turbine all the way in addition
The working medium inlet of machine is communicated;The working medium exit port pipeline of the pressure turbine is divided into two-way, wherein passing through all the way
Three valves are communicated with the working medium inlet of medium pressure turbine, pass through the entrance phase of the 4th valve and condenser all the way in addition
It is logical;The working medium exit port of medium pressure turbine is communicated with the entrance of the condenser.
It is preferred that, the heating medium inlet pipeline of second power generation cycle sets heating medium block valve, cooling medium
Entrance pipe sets cooling medium block valve, and the controller generates electricity according to heating medium and the first power generation cycle and second and followed
First valve described in the working state control of ring, the second valve, the 3rd valve, the 4th valve, heating medium block valve and cold
But the switch of medium block valve.
It is preferred that, first power generation cycle and the second power generation cycle have the electricity for the generated energy for detecting each self generator
Force detector, first power generation cycle sets heating medium supplying temperature in the entrance and exit of the heating medium of its evaporator
Detector and heating medium discharge temperature detector.
It is preferred that, when the temperature of supply heating medium increases from low to high, the controller starts first hair successively
The high-pressure turbine of pressure turbine, the middle-pressure turbine of first power generation cycle and second power generation cycle that electricity is circulated
Machine.
It is preferred that, when supply heating medium temperature from high to low, the controller closes the first power generation cycle successively
The pressure turbine of middle-pressure turbine, the second power generation cycle;Then, start the middle-pressure turbine of the first power generation cycle, close the
The pressure turbine of one power generation cycle.
As another aspect of the present invention there is provided the control method of above-mentioned electricity generation system, wherein, when supply heating is situated between
When the temperature of matter increases from low to high, the rate-determining steps of turbine include:1)Start pressure turbine;
2)Compare the detected value of the detected value and heating medium discharge temperature detector of heating medium supplying temperature detector
Difference △ Th and temperature difference threshold value Sth size, if △ Th<=Sth, into step 21;If △ Th>Sth, into step
Rapid 22;
21)Compare the first power generation cycle generated output power W1 and Sp1 size, wherein Sp1 is the first power generation cycle
The corresponding optimization power threshold of pressure turbine, if W1>=Sp1, into step 2);If W1<Sp1, into step 211);
211)The pressure turbine of the first power generation cycle is closed, starts the middle-pressure turbine of the first power generation cycle, into step
Rapid 212);
212)Compare the detection of the detected value and heating medium discharge temperature detector of heating medium supplying temperature detector
The difference △ Th and temperature difference threshold value Sth of value size, as △ Th>During Sth, into step 213);
213)Start the second power generation cycle, into step 214);
214)Compare the detection of the detected value and heating medium discharge temperature detector of heating medium supplying temperature detector
The difference △ Th and temperature difference threshold value Sth of value size, as △ Th>During Sth, into step 215);
215)Start the pressure turbine of the first power generation cycle;
22)Start middle-pressure turbine, into step 221);
221)Compare the detection of the detected value and heating medium discharge temperature detector of heating medium supplying temperature detector
The difference △ Th and temperature difference threshold value Sth of value size, as △ Th>During Sth, into step 222);
222)Start the second power generation cycle.
It is preferred that, when the turbine of the first power generation cycle and the second power generation cycle is all in startup, and supplies heating and be situated between
When the temperature of matter is reduced from high to low, rate-determining steps include:
a)Compare the first power generation cycle generated output power W1 and the second power generation cycle generated output power W2 it
With W1+W2 and Sp1+Sp2+Sp3 size, wherein Sp2 is the corresponding optimization power threshold of the first power generation cycle middle-pressure turbine,
Sp3 is the corresponding optimization power threshold of the second power generation cycle pressure turbine;If W1+W2<Sp1+Sp2+Sp3, then enter step
Rapid b);
b)Middle-pressure turbine is closed, into step c);
c)Compare W1+W2 and Sp1+Sp3 size, if W1+W2<Sp1+Sp3, into step d);
d)The pressure turbine of the first power generation cycle is closed, middle-pressure turbine is opened;Into step e)
e)Compare W1+W2 and Sp1 size, if W1+W2<=Sp2, into step f);If Sp2<W1+W2<Sp1;Enter
Enter step h;
f)Close the second power generation cycle;
h)The second power generation cycle and middle-pressure turbine are closed, the pressure turbine of the first power generation cycle is opened.
Brief description of the drawings
Fig. 1 is the power generation system structure schematic diagram of the embodiment of the present invention.
Fig. 2 is the part control flow chart of the electricity generation system of the embodiment of the present invention.
Fig. 3 is another part control flow chart of the electricity generation system of the embodiment of the present invention.
Embodiment
Following embodiments of the present invention, are disclosed together with their advantages and features, will be by reference to following explanation
Become obvious with accompanying drawing.Furthermore, it is to be understood that the feature not mutual exclusion of various embodiments described here, and can be
Exist during various combinations and transformation.
Referring to Fig. 1, the electricity generation system of embodiments of the invention, including the first power generation cycle 1a, the second power generation cycle 1b with
And controller 9.First power generation cycle 1a and the second power generation cycle 1b include respectively, evaporator 2, pressure turbine 3, condenser
4th, transfer tube 5, generator 7 and power detector 8.
Heating medium from middle low-temperature heat source(Such as vapor)Medium will be heated by heating medium feeding pipe
It is transported to respectively by branch road 12 in first power generation cycle 1a and the second power generation cycle 1b evaporator 2 from main line 10, so that
Heat the working media in the first power generation cycle 1a and the second power generation cycle 1b(Such as normal butane, iso-butane, ammonia), the work
Make media drive the first power generation cycle 1a and the second power generation cycle 1b turbine movements, so as to drive the first power generation cycle 1a
And second power generation cycle 1b generator 7 generated electricity.Exported from the first power generation cycle 1a and the second power generation cycle 1b
Medium is heated, heating medium output pipe main line 11 is convergeed to by output pipe 13 respectively and discharged.
Cooling medium feeding pipe is by cooling medium(Such as cooling water)Is transported to from main line 14 by branch road 16 respectively
One power generation cycle 1a and the second power generation cycle 1b condenser 4, generate electricity for cooling down from the first power generation cycle 1a and second
Circulate the working media of 1b turbines discharge.The cooling medium exported from the first generating ring 1a and the second power generation cycle 1b, point
The main line 15 of cooling medium output pipe is not convergeed to by branch road 17 and discharged.
Wherein, the first power generation cycle 1a is additionally provided with middle-pressure turbine 31.Pressure turbine 3 and middle-pressure turbine 31 are logical
Cross rotating shaft to couple with generator 7, so as to drive generator 7 to be generated electricity.First power generation cycle 1a is set to, and evaporator 2 works
The export pipeline of medium is divided into two-way, wherein communicated all the way by the first valve 21 with the working medium inlet of pressure turbine 3,
Communicated all the way by the second valve 22 with the working medium inlet of middle-pressure turbine 31 in addition;The working media of pressure turbine 3
Export pipeline is divided into two-way, wherein being communicated all the way by the 3rd valve 23 with the working medium inlet of middle-pressure turbine 31, in addition
Communicated all the way by the 4th valve 24 with the entrance of condenser 4;The working medium exit port of middle-pressure turbine 31 enters with condenser 4
Mouth is communicated.First power generation cycle 1a sets heating to be situated between in the entrance pipe 12 and export pipeline 13 of the heating medium of its evaporator 2
Matter supplying temperature detector and heating medium discharge temperature detector.
Control device 9 is by controlling opening for the first valve 21, the second valve 22, the 3rd valve 23 and the 4th valve 24
Close, the working condition of steam turbine in the first power generation cycle 1a can be controlled.Wherein, the first valve 21, the second valve 22 and
Four valves 24 are opened, and when the 3rd valve 23 is closed, pressure turbine 3 and middle-pressure turbine 31 are all defeated using flash-pot 2 is carried out
The steam gone out, with maximum rated output power;First valve 21, the 3rd valve 23 are opened, the second valve 22 and the 4th
When valve 24 is closed, the reduction of its rated output power;First valve 21, the 4th valve 24 are opened, the second valve 22, the 3rd valve
During 23 closing, its rated output power is further reduced;First valve 21, the 3rd valve 23, the 4th valve 24 are closed, the second valve
When door 22 is opened, its rated output power is minimum.
Second power generation cycle 1b heating medium inlet pipeline 12 sets heating medium block valve 18, cooling medium inlet tube
Road 16 sets cooling medium block valve 19.When heating medium block valve 18 and cooling medium block valve 19 blocks pipeline, the
Two power generation cycle 1b's is stopped.Controller 9 is examined according to heating medium supplying temperature detector and heating medium discharge temperature
Survey device measured value, and the first power generation cycle and the second power generation cycle working state control the first valve 21, the second valve
22nd, the switch of the 3rd valve 23, the 4th valve 24, heating medium block valve 18 and cooling medium block valve 19.
When the electricity generation system of the present embodiment is in zero load, according to the measurement of temperature detector, supply heating medium is judged
When temperature increases from low to high, controller 9 control the first valve 21, the second valve 22, the 3rd valve 23, the 4th valve 24, plus
Thermal medium block valve 18 and cooling medium block valve 19, the pressure turbine 3, first for starting the first power generation cycle 1a successively are sent out
The middle-pressure turbine 31 of electricity circulation and the pressure turbine 3 of second power generation cycle.
It is fully loaded with when the electricity generation system of the present embodiment is in, all turbines are all in running status, according to temperature detector
Measurement, judge when supply heating medium temperature from high to low when, controller 9 controls the first valve 21, the second valve 22, the
Three valves 23, the 4th valve 24, heating medium block valve 18 and cooling medium block valve 19, close the first power generation cycle successively
1a middle-pressure turbine 31, the pressure turbine 3 of the second power generation cycle;Then, the middle-pressure turbine of the first power generation cycle is started
31, close the pressure turbine 3 of the first power generation cycle.
By the above-mentioned control mode of the present invention, middle-pressure turbine and corresponding control by the first power generation cycle 1a
The setting of valve, when the heat from heat source of middle low-temperature heat source significantly changes, preferentially passes through the turbine in the first power generation cycle 1a
Switch, adjust the operating power of electricity generation system, so as to reduce the switching requirements for the second power generation cycle 1b, improve and be
The conformability of system, and add adjustable power bracket.
The part control method of the electricity generation system of the embodiment of the present invention, as shown in Figure 2(The turbine of startup is not write exactly wherein
Expression is closed), when the temperature of supply heating medium increases from low to high, the rate-determining steps of turbine include:1)
Start pressure turbine;
2)Compare the detected value of the detected value and heating medium discharge temperature detector of heating medium supplying temperature detector
Difference △ Th and temperature difference threshold value Sth size, if △ Th<=Sth, into step 21;If △ Th>Sth, into step
Rapid 22;
21)Compare the first power generation cycle generated output power W1 and Sp1 size, wherein Sp1 is the first power generation cycle
The corresponding optimization power threshold of pressure turbine, if W1>=Sp1, into step 2);If W1<Sp1, into step 211);
211)The pressure turbine of the first power generation cycle is closed, starts the middle-pressure turbine of the first power generation cycle, into step
Rapid 212);
212)Compare the detection of the detected value and heating medium discharge temperature detector of heating medium supplying temperature detector
The difference △ Th and temperature difference threshold value Sth of value size, as △ Th>During Sth, into step 213);
213)Start the second power generation cycle, into step 214);
214)Compare the detection of the detected value and heating medium discharge temperature detector of heating medium supplying temperature detector
The difference △ Th and temperature difference threshold value Sth of value size, as △ Th>During Sth, into step 215);
215)Start the pressure turbine of the first power generation cycle;
22)Start middle-pressure turbine, into step 221);
221)Compare the detection of the detected value and heating medium discharge temperature detector of heating medium supplying temperature detector
The difference △ Th and temperature difference threshold value Sth of value size, as △ Th>During Sth, into step 222);
222)Start the second power generation cycle.
Another part control method of the electricity generation system of the embodiment of the present invention, as shown in Figure 3(The whirlpool of startup is not write exactly wherein
Turbine represents to be closed), when the turbine of the first power generation cycle and the second power generation cycle is all in startup, and supply
When the temperature of heating medium is reduced from high to low, rate-determining steps include:
a)Compare the first power generation cycle generated output power W1 and the second power generation cycle generated output power W2 it
With W1+W2 and Sp1+Sp2+Sp3 size, wherein Sp2 is the corresponding optimization power threshold of the first power generation cycle middle-pressure turbine,
Sp3 is the corresponding optimization power threshold of the second power generation cycle pressure turbine;If W1+W2<Sp1+Sp2+Sp3, then enter step
Rapid b);
b)Middle-pressure turbine is closed, into step c);
c)Compare W1+W2 and Sp1+Sp3 size, if W1+W2<Sp1+Sp3, into step d);
d)The pressure turbine of the first power generation cycle is closed, middle-pressure turbine is opened;Into step e)
e)Compare W1+W2 and Sp1 size, if W1+W2<=Sp2, into step f);If Sp2<W1+W2<Sp1;Enter
Enter step h;
f)Close the second power generation cycle;
h)The second power generation cycle and middle-pressure turbine are closed, the pressure turbine of the first power generation cycle is opened.
In addition, those skilled in the art can also do other changes in spirit of the invention, without departing from the present invention's
Technique effect.These according to the change done of present invention spirit, should all be included in scope of the present invention it
It is interior.