SFOC Optimisation with Low Load or Part Load Exhaust Gas Bypass (LL-EGB, PL-EGB)

Transcription

1 MAN Diesel & Turbo Market Update Note 21 February 2014 SFOC Optimisation with Low Load or Part Load Exhaust Gas Bypass (LL-EGB, PL-EGB) All ME-C/ME-B engines with high-efficiency turbocharger and LL-EGB or PL-EGB tuning Economiser energy control (EEC) option Recently, MAN Diesel & Turbo evaluated the need for introducing additional engine optimisation and bypass control strategies to supplement LL-EGB and PL-EGB basic modes to increase the total energy efficiency. Fig. 1 shows the system principle for engines tuned with low load or part load EGB. Fig. 1: Engine tuned with EGB connected to exhaust boiler HEAD OFFICE (& postal address) MAN Diesel & Turbo Teglholmsgade Copenhagen SV Denmark Phone: Fax: mandiesel-cph@mandieselturbo.com PrimeServ Teglholmsgade Copenhagen SV Denmark Phone: Fax: PrimeServ-cph@mandieselturbo.com PRODUCTION Teglholmsgade Copenhagen SV Denmark Phone: Fax: manufacturing-dk@mandieselturbo.com FORWARDING & RECEIVING Teglholmsgade Copenhagen SV Denmark Phone: Fax: shipping-cph@mandieselturbo.com MAN Diesel & Turbo Branch of MAN Diesel & Turbo SE, Germany CVR No.: Head office: Teglholmsgade Copenhagen SV, Denmark German Reg.No.: HRB Amtsgericht Augsburg MAN Diesel & Turbo a member of the MAN Group

2 MAN Diesel & Turbo Manual opening of the EGB valve in the engine load range between 35% and 85% can significantly boost the exhaust gas boiler steam production, making it easier to fulfil the steam demand by no or limited use of the oil-fired boiler. The ships total fuel consumption will be lower when allowing the engine to use a little more fuel due to the opening of the EGB, compared with running the oil-fired boiler, see the example in the enclosed presentation. In order to optimise total energy consumption of the ship under all operation conditions and without manual interference, we are now introducing a new option, the Economiser Energy Control system, which will enable the supplier of the steam boiler to send a signal to the engine s control system to increase the available exhaust gas energy. The signal is physically connected to the EGB controller on the engine (SCU). The system will secure an optimal relation between steam production requirement and engine SFOC by automatic adjustment of EGB position, and thereby exhaust gas temperature, within the acceptable boundary given by the engine illustrated in Fig. 2. Fig. 2: EGB valve opening, min.-max. The basic PL-EGB or LL-EGB control will always keep the bypass as closed as possible taking engine/turbocharger mechanical loading and engine NO x production into consideration. The EEC system will, as shown in Fig. 2, only be allowed to open the bypass more than the basic PL-EGB or LL-EGB bypass position (blue line in Fig. 2). Opening the by-pass will always reduce NO x production. Accordingly, the EEC system can be used without amendments to the IMO technical file. Test bed SFOC guarantees should only be given for the basic PL-EGB or LL-EGB control with the EEC system disengaged.

3 MAN Diesel & Turbo The EEC system requires that the boiler manufacturers extend their existing steam pressure control system to include a control loop (increase exhaust gas energy) sending signals to the main engine control system. The boiler manufacturers steam pressure control system already controls steam dump and start/stop of the oil-fired boiler. This extra control loop will enable an optimal synchronous control of the main engine and exhaust boiler, resulting in lower total fuel consumption. Only the full and complete version of this letter may be reproduced and/or displayed by the receiver. Best regards MAN Diesel & Turbo Niels B Clausen Leif Hauerslev Encl.: Steam Production the SFOC/exhaust gas energy dilemma

4 The SFOC / exhaust gas energy dilemma 75,000 Dwt Bulk Carrier as case Bent Ørndrup Nielsen Senior Research Engineer LEE4 / Marine Installation Marine Low Speed, Engineering < 1 >

5 SFOC - exhaust temperature and amount Basis: Lower SFOC values means lower exhaust gas temperatures (less energy in exhaust gas) Exhaust gas boiler design criteria before (standard): Exhaust gas boiler must be able to cover service steam need at % SMCR at ISO condition. The normal ship specification requirement. Exhaust gas boiler design criteria now: Exhaust gas boiler must be able to cover service steam need at (50%) 75% SMCR at ISO condition (Winter condition?). What can MAN Diesel & Turbo offer? < 2 >

6 Bulk Carrier and Composite boiler Typical engine room for Bulk Carrier Composite boiler < 3 >

7 Panamax bulk carrier Typical ship data for 75,000 dwt Bulk Carrier: Length, o.a.: Breadth, moulded: Draught, design: Service speed: Propeller: Main Engine: Aux. diesel: Boiler, composite type: 225 meter meter meter 14.5 knots 6.2 meter 4 bladed B&W 6S50ME-B9.3 TII, High load tuned SMCR: 8310 kw x 110 rpm 3 x 500 kw 1500 / 2000 kg/h (Exhaust part/ oil fired part) Typical operational profile: Operational hours per year at sea: 6000 hours 100% engine load: 2% 85% engine load: 35% 65% engine load: 45% 50% engine load: 3% 25% engine load: 15% < 4 >

8 Bulk Carrier and Composite boiler 75,000 dwt bulk carrier steam balance Detailed steam balance Cold condition (10 deg C) Normal condition (25 deg C) Tropical condition (45 deg C) Cold condition: Normal condition: Tropical condition: Steam consumers: Max At sea In port Max At sea In port Max At sea In port cons cons cons kg/h LF kg/h LF kg/h kg/h LF kg/h LF kg/h kg/h LF kg/h LF kg/h Preheaters FO booster unit Preheater for HFO purifier Preheater for HFO/DO purifier Preheater for LO purifier FW preheater for ME heating AC heating section AC humidifier Steam calorifiers Hot water calorifier Heattracing HFO pipes Sludge tank Bilge holding tank HFO storage tank P HFO storage tank P HFO storage tank S HFO storage tank S HFO settling tank HFO settling tank FO overflow tank FO service tank Lub oil renovation tank Scavenge air drain tank Leak oil tank Sea chest blowing Heatloss estimated 5% TOTAL: Note: For ships operating in areas with lower ambient temperature extra steam balance calculations must be added. < 5 >

9 Panamax Bulk Carrier Propulsion of 70,000-80,000 dwt Increased propeller diameter 6G50ME-B9.3 (M3 ) < 6 >

10 Panamax Bulk Carrier Alternative main engine Increased propeller diameter and thereby lower rpm: 6S50ME-B9.3 SMCR: 8310 kw at 110 rpm Replaced with: 6G50ME-B9.3 SMCR: 7950 kw at 94 rpm Lower engine power by using a 6.7 meter 4 bladed propeller 3.4% saving in power requirement The impact on main engine FOC, steam production, boiler FOC and total fuel economy will be shown on the following slides. < 7 >

11 Assumptions Steam calculation Steam data calculation assumptions Feedwater temp: 80 C Steam pressure: 7 bar Pinch point: 20 C Exhaust gas spec. heat capacity: 1.06 kj/kgk Tin, boiler = Teng,exhaust 2 C (temperature drop between engine and boiler) Enthalpy steam (vapor) hst: kj/kg Enthalpy feedwater hfw: kj/kg Heat balance: Estimated fuel consumption for boiler: 7.3 kg/h fuel per 100 kg/h steam Final steam production must be confirmed by boiler maker. < 8 >

12 Main engine SFOC The engine alternatives that are included in this analysis are: 6S50ME-B9.3 HL 6G50ME-B9.3 PL-EGB 6G50ME-B9.3 PL-EGB and manual open EGB (40 to 85%) < 9 >

13 Main engine exhaust gas temperatures < 10 >

14 Main engine exhaust gas flow < 11 >

15 Main engine and oil-fired boiler steam production. Steam consumption 820 kg/h (ISO) Note: Exhaust boiler output data is based on a pinch point of 20 deg. C, standard layout of the boiler using the acceptable back pressure and a outlet temperature between deg. C depending on steam pressure. < 12 >

16 Main engine and oil-fired boiler steam production. Composite oil fired part supplementary steam production. < 13 >

17 Main engine fuel consumption and boiler 6S50ME-B9.3 TII 6G50ME-B9.3 TII 6G50ME-B9.3 TII HL PL EGB MANUAL PL EGB Load ME FOC B FOC FOC Total ME FOC B FOC FOC Total ME FOC B FOC FOC Total %SMCR kg/h kg/h Ton/day kg/h kg/h Ton/day kg/h kg/h Ton/day Fuel Oil Consumption (FOC) of main engine and supplementary oil fired in boiler to meet steam demand at ISO condition. A total steam demand of 820 kg/hour (ISO condition) has been assumed. < 14 >

18 Main engine steam production & ambient conditions Both engines meet the necessary steam consumption in tropical condition, but supplementary oil firing in boiler is required both for ISO and winter conditions. What can MDT offer to improve the steam output, without to high an impact on FOC? < 15 >

19 at ISO conditions Total fuel oil consumption for ship s operational profile Bulk Carrier Operational profile and yearly fuel consumption for Main engine and composite boiler (oil fired part) - ISO condition. Operational days at sea: 250days Operational hour per year: 6000hours Basis Alt. 1 Alt. 2 HFO price per ton: 600$ 6S50ME-B9.3 TII HL 6G50ME-B9.3 TII PL-EGB 6G50ME-B9.3 TII PL-EGB Manual (40-85%) Time per year Engine power Ship speed Hours ME FOC B FOC FOC Total ME FOC B FOC FOC Total ME FOC B FOC FOC Total % % knots hrs kg/h kg/h Ton kg/h kg/h Ton kg/h kg/h Ton , , , Big FOC saving by changing from 6S50ME-B9.3 to 6G50ME-B9.3, and further smaller savings by applying manual control of EGB. This conclusion only apply for this operational profile at ISO conditions. Saving per year, ton: Saving per year, $, compared to basis: 177, ,168 Saving per year, $, compared to Alt. 1: 26,361 < 16 >

20 at ISO conditions Total fuel oil consumption Big FOC saving by changing from 6S50ME-B9.3 to 6G50ME-B9.3, and further smaller savings by applying manual control of EGB. This conclusion only apply for this operational profile at ISO conditions. So what is the effect by dividing the yearly operational hours over ISO, Tropical and Winter (Special) conditions? < 17 >

21 at ISO conditions Total fuel oil consumption for ship s operational profile The operational profile is in the following calculated divided with 70% of the yearly hours at sea at ISO condition: Bulk Carrier Operational profile and yearly fuel consumption for Main engine and composite boiler (oil fired part) - ISO condition. Operational days at sea: 250days Operational hour per year: 6000hours Basis Alt. 1 Alt. 2 HFO price per ton: 600$ 6S50ME-B9.3 TII HL 6G50ME-B9.3 TII PL-EGB 6G50ME-B9.3 TII PL-EGB Manual (40-85%) Time per year Engine power Ship speed Time Hours ME FOC B FOC FOC Total ME FOC B FOC FOC Total ME FOC B FOC FOC Total % % knots factor hrs kg/h kg/h Ton kg/h kg/h Ton kg/h kg/h Ton , , , < 18 >

22 at Tropical conditions Total fuel oil consumption for ship s operational profile 20% of the yearly operational hours at Tropical condition: Bulk Carrier Operational profile and yearly fuel consumption for Main engine and composite boiler (oil fired part) - Tropical condition. Note: Manual opening of EGB under tropical condition is not economical recommendable. Operational days at sea: 250days Operational hour per year: 6000hours Basis Alt. 1 Alt. 2 HFO price per ton: 600$ 6S50ME-B9.3 TII HL 6G50ME-B9.3 TII PL-EGB 6G50ME-B9.3 TII PL-EGB Manual (40-85%) Time per year Engine power Ship speed Time Hours ME FOC B FOC FOC Total ME FOC B FOC FOC Total ME FOC B FOC FOC Total % % knots factor hrs kg/h kg/h Ton kg/h kg/h Ton kg/h kg/h Ton , For Alt. 2: Manual EGB operation is not used at Tropical condition, as the engine in normal Part load EGB tuning supplies sufficient energy for steam production without manual EGB override. < 19 >

23 at Winter conditions Total fuel oil consumption for ship s operational profile 10% of the yearly operational hours at Winter (Special) condition: Bulk Carrier Operational profile and yearly fuel consumption for Main engine and composite boiler (oil fired part) - Special condition. Operational days at sea: 250 days Operational hour per year: 6000 hours Basis Alt. 1 Alt. 2 HFO price per ton: 600 $ 6S50ME-B9.3 TII HL 6G50ME-B9.3 TII PL-EGB 6G50ME-B9.3 TII PL-EGB Manual (40-85%) Time per year Engine power Ship speed Time Hours ME FOC B FOC FOC Total ME FOC B FOC FOC Total ME FOC B FOC FOC Total % % knots factor hrs kg/h kg/h Ton kg/h kg/h Ton kg/h kg/h Ton Total FOC for the full year at sea: 6, Total FOC costs for the full year at sea: 3,296,899 3,113,717 3,088,493 Fuel cost savings per year: 183, ,406 Extra Fuel saving per year, manual EGB 25,225 The Total FOC for the hole year taking ISO, Tropical and Winter conditions show, that changing the engine to 6G50ME-B9.3 is an big advantage and it is further an advantage to used manual EGB in the power range between 40 85% load. < 20 >

24 Total fuel oil consumption for ship s operational profile < 21 >

25 Variable EGB opening effects - SFOC (ISO) ME SFOC variations' with the EGB valve opening at 25%, 50%, 75% and full open. < 22 >

26 Variable EGB opening effects - Exhaust temp. (ISO) ME exhaust temperature variations with the EGB valve opening < 23 >

27 Variable EGB opening effects - ME steam prod. (ISO) ME Steam production variations with the EGB valve opening So 75% open EGB valve nearly fulfils the steam demand down to 50% engine load. < 24 >

28 Variable EGB opening effects - Oil fired boiler (ISO) Oil fired boiler steam production variations' with the EGB valve opening < 25 >

29 Economizer Energy Control (EEC) for optimum steam production MDT can raise the exhaust temperature by opening the EGB valve in the engine power range between 35% and 85% load. A signal from the exhaust gas economizer control system is needed to automatize and optimise steam production < 26 >

30 Economizer Energy Control (EEC) for optimum steam production Low load or Part load tuned engines with EGB will have an EGB valve opening following a Load dependent min. Required opening (the blue line). MDT allow opening the EGB up to a load dependent max. Opening (the red line) if more energy to the economizer is needed to meet the ships steam demand. The external Economizer Energy Control system (EEC) may control the EGB position between these limit to maintain the optimal EGB valve opening by an increase / decrease signals from the boiler manufactures Exhaust Gas Economizer Control System (EGECS) to the engine control system. < 27 >

31 Economizer Energy Control (EEC) for optimum steam production A: Engine starting and aux. Boiler in operation. Aux. Boiler closed when the preset pressure is achieved. B: Steam pressure kept at setpoint by opening / closing EGB valve. Steam pressure Steam dump valve setpoint EGB Steam Pressure setpoint Aux burner off Aux burner on C: EGB valve fully closed or with EGB open to the extend defined by the engine tuning method, providing steam power in excess of the required steam amount. A B C D EGB valve position Time D: Steam pressure at pressure setpoint and EGB valve control in function EGB Max pos. EGB Min pos. The EEC can control the EGB valve within the allowed limits to maintain the required steam pressure < 28 >

32 Economizer Energy Control (EEC) for optimum steam production The EEC system requires, that the boiler manufacture include a continuous Steam pressure controller in their control system. This can secure, that a increase / decrease signal can be send to the main engine control system (ECS) for the control of the EGB valve. < 29 >

33 Economizer Energy Control (EEC) for optimum steam production The interface for the increase signal can be seen at this screen-dump for the engine control system This option is available in MDT software named ME-ECS released February < 30 >

34 Other possibilities Other possibilities to boost available service steam: Conventional Turbo Charger can be selected for all high load tuned engines - resulting in increased exhaust temperature abt. 20 deg C and higher steam production, but with 1 g/kwh in SFOC penalty for all conditions (ISO, Tropical and Winter). The separate aux. engine boilers can also be integrated in the main composite boiler. Boiler solutions with oil fired part, main engine exhaust part and three aux. engine exhaust parts in one composite boiler is available in the marine marked. Lowering the service steam pressure from 7 bar to 5 bar will increase the available steam output, this is a possibility as most of the steam consumers requires a minimum steam temperature of only abt. 130 deg C. The only consumers needing a higher steam pressure is the fuel oil heater for the main engine and possible aux. engine. It requires a steam temperature abt. 165 deg C (7bar), but an electric heater could then be used to achieve the correct temperature for the fuel according to the required fuel viscosity. If low viscosity fuels are to be used, the steam pressure setpoint could then be lowered and more steam be produced. < 31 >

35 Composite boiler for main engine and auxiliary engines Alfa Laval composite boiler for main engine, oil fired part and two auxiliary engines Greens composite boiler for main engine, oil fired part and two auxiliary engines < 32 >

36 Conclusions Bigger propeller improves propulsion efficiency, as the propulsion power requirement reduces by 3.4% when 6G50ME-B9.3 is used compared even with the newest generation S50ME-B9 engine design. 6G50ME-B9.3 EGB part load tuned shows best SFOC performance. 6G50ME-B9.3 with EGB part load can allow to open bypass fully between 85% - to 40% load when otherwise closed. This allows increased exhaust temperature, and improved steam production. 6G50ME-B9.3 with EGB part load and variable bypass valve opening can further optimize the total fuel consumption. 6G50ME-B9.3 with EGB part load and bypass fully open shows improved performance when boiler fuel consumption is included. Most flexible solution with no additional fuel consumption at tropical condition. Further optimizing possible by using automatic Economizer Energy Control (EEC) ensuring optimal EGB opening for the needed steam production. < 33 >

37 Thank You for Your Attention! All data provided in this document is non-binding. This data serves informational purposes only and is especially not guaranteed in any way. Depending on the subsequent specific individual projects, the relevant data may be subject to changes and will be assessed and determined individually for each project. This will depend on the particular characteristics of each individual project, especially specific site and operational conditions. < 34 >