Technical Field :

this invention is related to a process_that is added to a steam flowing factory, consists of 6 steam generators of type (Once Through Steam Generators) "OTSG ^M , to improve the steam Efficiency in percentage of 3%, during the process of Bitumen thermal extraction from the oil sands in Canada, by (steam assessment of gravitational drainage) "SAGD".

Background Art:

1- mutual generating technology produces steam and electricity simultaneously, for example, Petro-Canada project in Fort McMurray, that consists of Gas turbine with Efficiency of 172 Megawatts of type"GE7FA" and unit "OT- HRSG" (Once-Through Heat Recovery Steam Generator) to return the required heat for enhancing oil recovery from exhaust gases, using 12 electric Megawatts to run the location, while the rest of the electric power would be sold to Alberta Electricity network.

2- Vacuum Insulated Tubing is group of insulated tubes inside the wells for the purpose of decreasing the heat loss.

3- Molten Carbonate Fuel Cells collect Carbon Dioxide from (Once-Through Heat Recovery Steam Generator) units, which are running by natural gas and electricity generating.

Disclosure of the Invention:

- Basically, steam generating of Bitumen flowing process from oil sands by steam assessment of gravitational drainage. - This steam is producing by Once-Through Heat Recovery Steam Generator (see figure2) what shows a diagram of steam production process by 6 steam generators of type (Once-Through Heat Recovery Steam Generator), the source of the drawing is "Canada's Oil Sands Innovation Alliance" "COSIA", seeing the (figure2) we find that:

*steam weight that results from 6 steam generators of type (Once-Through Heat Recovery Steam Generator) = 851624Kg/hr

* Steam quality= 77%

*Input energy= 1538GJ hr natural gas + 63GJ/hr produced gas

Electrical loads = 17.9mw/hr , equalizes the heat energy 1 17.3 GJ/hr, which means that, electricity production Efficiency is 55%

- The invention aim is improving the steam Efficiency in percentage of 3% for the steam production process that was shown in (figure2).

*Detection of the invention ( see figurel)

- The invention is a process that is added to 6 steam generators (Once- Through Heat Recovery Steam Generator) that result what follow:

1 - 67500 Kg/hr , with steam quality of 77%

2- 17.9 Mega watt Electrical power that are required to run the location

3- 37GJ/hr heat energy that is added to the intake combustion air to 6 steam generators

- This process consumes 231 GJ/hr This process consists of three phases:

First phase: the process of heating 67500Kg/hr of the water that feeds the process (the subject of invention) to 250C° Second phase: the process of producing 67500Kg/hr of steam in quality of 77%, and producing of 17.9 electric Megawatts that are required to run the location

Third phase: the process of heating of the intake Combustion air to 6 steam generators (Once-Through Heat Recovery Steam Generator) to 160C°

We will discuss each phase by details:

First phase: the process of heating 67500Kg/hr of the water that feeds the operating (the subject of invention) to 250C°, (see figure 1 ): - The feed water exits after HP BFW pump in flow rate of 851624/hr , pressure of lOOBar., and temperature of 146C° -TDS 6000 ppm

- Some of the feed water is been taken - before entering to (BFW pre heater)- in flow rate of 67500Kg/hr by tube "1 ", so be entered through stopcock "2" to pre heater "A", this water is called feed water of the process (the subject of invention)" as shown in(figurel) - As a result, the intake feed water to feed 6 steam generators (Once-Through Heat Recovery Steam Generator) may decrease to 784124 Kg/hr, then it pass through (BFW pre heater), so its temperature will increase from 146C ⁰ to be 170C°, during the operating of heat exchange with the water( blow down).

- By seeing (figure 1 ), we find that, (preheater "A") is located between (BFW preheater) unit and (LP steam flash) unit.

It is useful for adding a part of heat energy the water

(blow down= 1964040Kg/hr) have, after exiting of (BFW pre heater) to the feed water of the process (67500Kg/hr)

- Designing information of preheater "A"

( see figure 1) Flow Water blow down Feed Water

1- Flow rate Kg/hr 196404Kg/hr 67500Kg/hr

2- Temperature in 210C° 146 C°

3- Temperature out 189 C° 203 C°

4- Operating pressure 100 bar 100 bar

5- Allowable pressure 1-2 bar 0.0 to 0.02 bar

6- Heat duty GJ/hr 17. GJ/hr28 16.105GJ/hr

7- Foozling resistance

8- Viscosity in/out

9- Design pressure bar

10- Line size mm nominal

1 1 - Material of contraction

6- The process feed water exits from (preheater "A") through tube"3" via valve"4" to (preheater "B") at the pressure of 100 bar, temperature of 203 C°, and flow rate of 67500Kg/hr

7- By seeing (figurel), we find that, (preheater "B") is located

between HPS unit and (BFW preheater) unit.

It is useful for increasing the process feed water temperature from 203 C° to 250 C° without effecting the process of heat exchange of intake feed water to 6 steam generators (Once-Through Heat Recovery Steam Generator) during (BFW preheater) .

8- Designing information of preheater "A"

( see figurel )

Flow Water blow Feed Water

down

1 - Flow rate Kg/hr 196404 Kg/hr 67500 Kg/hr

2- Temperature in 31 1C° 146 C°

3- Temperature out 293C ⁰ 203 C°

4- Operating pressure bar 100 bar 100 bar

5- Allowable pressure drop 1-2 bar 0.0 to 0.02 bar 6- Heat duty GJ/hr 14.8GJ/hr 13.28 GJ/hr

7- Foozling resistance

h.m2 c/K cal

8- Viscosity in/out

9- Design pressure bar

10- Line size mm

1 1- Material of contraction

9- The affection of adding (preheater "A") and (preheater "B") to the process of heat exchange with the intake feed water to 6 steam generators (Once-Through Heat Recovery Steam Generator) during (BFW preheater) .

Firstly: counting of the thermal energy per kilogram of feed water before adding (preheater "A") and (preheater "B"), flow rate of the intake feed water before the addition to (BFW preheater) =

851624Kg/hr, (see figure2).

So, heat energy of each kilogram = 196404x4.186x (31 1- 220)/851624=87.8026KJ/Kg.

Secondly: counting of the heat energy per kilogram of feed water before adding (pre heater "A") and (pre heater "B").

Flow rate of the intake feed water after the addition to (BFW

preheater) = 784124 Kg/hr, (see figure 1 ).

So, heat energy per kilogram = 196404x4.186x (293-210)/784124= 87.024773KJ7Kg.

The result of the addition process has a slight negligible impact to the heat exchange process during (BFW pre heater).

10- By seeing to flow rate of water during (preheater "A") and (preheater "B") 67500 Kg/hr, comparing to the flow rate during (BFW preheater) = 784124 Kg/hr, by comparing to heat flow rate in an hour during (preheater "A") and (preheater "B") 17.26 of 14.8 GJ/hr respectively, and by comparing to heat flow rate during BFW preheater = 86 GJ/hr.

In conclusion, the size of (pre heater "A") and (pre heater "B") equal 1/5 of (BFW preheater) size applying the same technical specifications such as bearing pressure, temperature, and using of the same construction materials.By seeing figure (3), we will find that, the PROCESS of heating of the feed water of (once through heat recovery steam generators) "OTHRSG" unit is been run in one phase only by (preheater "A").

Second phase: the process of producing 67500Kg/hr of steam in quality of 77%, and producing 17.9 electrical Megawatts to run the location.

Feed water of PROCESS exits of(pre heater "B") through stopcock "5" in tube "6" to (OTHRSG) D unit, with the Following specifications:

- Temperature of 250C°

- Pressure of 100 bar

- Flow rate of 67500 Kg/hr

- Total dissolved solids "TDS" 6000 ppm

1- This PROCESS consists of two essential components: (see figure 1).

Firstly: Gas turbine (C) manufactured by General Electric, in accordance with the manufacturer technical specifications:

Model→LM 2000 JDE - Output mw→ 17.9M W/hr

- Heat rate KJ/ WH→ 10430 KJ equal 186.7 GJ/hr

- Pressure Ratio→ 15.3

- Speed (RPM)→ 3000

- Exhaust Gas flaw→63.7 kg/s equal 229320 kg/hr

- Exhaust Gas Temp.→ 496C°

Secondly: (OTHRSG) D unit, (see figure 1).

- Designing information of (OTHRSG) D unit, (see figure 1). Operating Pressure

The steam exits through tube " 13" in flow rate of 67500 kg/hr, from stopcock "14"heading for high pressure steam "HPS" unit, with the resulting steam of "6" steam generators (once through heat recovery steam generators)

Secondly: (OTHRSG) D unit, (see figure3).

- Designing information of (OTHRSG) D unit, (see figure3). 1-Feed water pressure 100 bar

2-steam pressure 100 bar

3-feed water temperature 210 C°

4-feed water Enthalpy 900 KJ/Kg

5-steam temperature 31 1 C°

6- steam quality 77%

7-feed water rate 65500 kg/hr

8-steam production 65500 kg/hr

9-Gas flow Kg hr 229320 kg/hr

10- Inlet gas temperature 496 C°

1 1 -Firing temperature T = 496 C° + 4130000

229320* 1.02

- 660 C° by Duct burner(8)

12-Duct burner(8) 41.3 GJ.hr

13-(OTHRSG) boiler duct equals 41.3 GJ.hr Duct burner(8) duty +

Exhaust Gas 1 17 GJ hr = 158.3 GJ/hr

14-Exit gas temperature 260 C°

Third phase: process of heating the intake combustion air into"6" steam generators (once through heat recovery steam generators) to 160 C°, (see figure 1 ).

1- Exhaust gases exit from (OTHRSG) D unit in flow rate of 230220 Kg/hr, and temperature of 300 C°

2- Exhaust gases enter to (Air Pre heater) F tube through the entrance "9", and then enter via (Air Pre heater) F.

3- Exhaust gases exit throughout the exit " 10" to the Stack"G" in the temperature of 135 C°

4- The intake combustion air enters into "6" steam generators (once through heat recovery steam generators) through the entrance " 1 1 ", in the opposite direction for the exhaust gases , the air path being spirally around the heating tubes to allow the maximum heat flowing to the required intake air for burning operation.

The air enters through the entrance " 1 1 " in flow rate of 440000 g/hr, and temperature of 55 C°

5- The air exits through the exit "12" into steam generators (once through heat recovery steam generators) in temperature of 160 C°, acquiring heat energy in quantity of 37 GJ/hr

6- Designing information of (Tubular Air Preheater)"F" (figure 1)

7- The number of tubes are determined in the heat the quantity of loss or decreasing of pressure

Changes that occur on "6" steam generators (once through heat recovery steam generators) after the addition of the PROCESS "The subject of invention"

(see figure 1)

Firstly: for feed water: feed water divides to two parts:

- The first part enters into "6" steam generators (once through heat recovery steam generators) = 784124 Kg/hr

- The second part enters into the PROCESS "The subject of

invention" = 67500 Kg/hr

Secondly: for the energy inputs: Secondly: for the energy inputs:

1- the input energy into "6" steam generators (once through heat recovery steam generators) Ql

Q= 1375 GJ/hr Natural gas + 63 GJ/hr produced gas + 37GJ/hr, heat energy added to the burning air

This energy is enough to transfer 784124 Kg hr of feed water to steam in quality of 77%

2- the energy that be consumed by the process "The subject of invention" Q2 (see figure 1)

Q2 = 41.3 GJ/hr firing natural gas by duct burner (OTHRSG) + 186.7 GJ/hr gas turbine = 228 GJ/hr gas turbine

Saving the energy after adding of the process "The subject of invention" to"6" steam generators (once through heat recovery steam generators)

- The consumed energy after the addition of the process "The subject of

invention" to produce 851624 Kg/hr of steam in quality of 77% = 1603 GJ/hr + 63 GJ

- Improving the quality = 100x 1603 -1655/ 1655= 3%

- Saving the energy = 52 GJ/hr equals 1248 GJ/day

The method of isolating the process "The subject of invention" of the (once through steam generators) "OTSG" to perform maintenance

(see figurel)

Firstly: isolating the process of heating the feed water of the process "The subject of invention" by closing the stopcocks " 1", "4", and "5"

Secondly: isolating the process of producing of steam and electrical energy that required for running the location by closing the stopcocks " 16", and " 15" along the energy supplying line, and closing the stopcock " 14" on the steam exit Thirdly: the process of heating the air does not need to close the isolating stopcocks

The invention's Advantages

1- To supply 1248 GJ/day of the additional heat energy daily.

2- There is no need for extra workers.

3- Easy to install inside the location, so, we can count on the portable or

movable units, since the elements which used are small-sized.

4- Availability of the containing elements of the process "The subject of

invention" in many companies.

5- The PROCESS "The subject of invention" may cover the costs of purchasing and installation during a period of 3 or 4 years, after that, it will be profit- making as a result of saving of energy.

Brief description of drawings:

figure 1 shows the invention subject's aspects adding to 6 steam generators "OTSG" , they consist of the following aspects:

A- Preheater, for heating the feed water of the PROCESS by blow down water that exits from (BFW pre heater water) unit to 203 C°.

B- Preheater, to increase the temperature of the feed water of the PROCESS from 203 C° to 250 C° by using blow down water that exits from (HPS) unit directly.

C- Gas turbine that made by General Electric Company, in model of

LM2000JDE, with Efficiency of 17.9 MW/h.

D- (OTHRSG) unit that is provided with 8 Duct Burner.

F-Tubular Air Pre heater.

G -Stack

• Figure (2) shows a diagram of "6" steam generators (once through steam generators) "OTSG". The source of the diagram is (COSIA) to be able to understand and compare after adding of the PROCESS "The subject of invention". Figures (3) differ from figure (1) that, there is no preheater (B), and make sufficiency only by preheater (A) to heat up the feed water of "OTHRSG" unit.