ecosmrt LNG Reliquefaction INTERTANKO 2 nd May 2018

Transcription

1 ecosmrt LNG Reliquefaction INTERTANKO 2 nd May 2018

2 Babcock International - at a glance The UK s leading engineering support services organisation Headquartered in London Delivering circa 600 services across six continents Employing a workforce of c 35,000 skilled personnel Annual Revenue over 4.5 billion Order book circa 19 billion Established in1891 FTSE 250 company listed on London Stock Exchange 2

3 Babcock LGE at a glance Rosyth (near Edinburgh) Scotland Revenue growth to more than 100m by development and application of Innovative Technology Patents & applications in multiple countries for LPG, Ethane, Ethylene and LNG Engineering Procurement Project Management 100 people 80% with Engineering qualifications Our customers are world s biggest commercial shipyards in Korea, China and Japan and tier 1 ship-owners 2016 winners of two Queen s Awards International Trade & Innovation Established in nationalities 3

4 ecosmrt Design Challenges Reduce CAPEX Deliver higher reliquefaction capacity Minimise equipment Smaller plant reduce the footprint Reduce installation cost Reduce OPEX Increase efficiency reduce fuel consumption Minimise rotating equipment for ease of operation Simpler plant requiring less maintenance Babcock LGE took up this challenge and work began in August The concept design was completed in April 2016 and patent application (UK ) filed in June A second patent application (UK ) was filed in August Today the design is fully matured with Approval in Principle (AiP) by LR and first sales in February 2018 for 4 off SMR units for TMS Cardiff and Sovcomflot. 4

5 ecosmrt Existing Reliquefaction Plant Reverse Brayton Nitrogen Plant Simple cycle but added complexity of compander for power recovery Low efficiency with poor COP resulting in high power consumption Mixed Refrigerant (MR) Plant Requires external pre-cooling Multiple pieces of rotating equipment Risk of oil contamination of the PFHE 5

6 ecosmrt Design Development Existing LNG MR reliquefaction ecosmrt EXTERNAL PRECOOLING INTEGRATED PRECOOLING Removal of secondary refrigeration loop comprising: Screw compressor / motor and oil management system Five heat exchangers Additional pressure vessels Integrated cooling leads to a much simpler process and control system 40% reduction in footprint 50% reduction in maintenance Developed to use known and proven technology (no prototyping) 6

7 ecosmrt Process Visualisation 7

8 ecosmrt Process Visualisation SMR compression and heat rejection 1. Warm MR gas (>35 C) enters the compressor suction at low pressure (<10 bara). 2. The MR is compressed to the high pressure (>20 bara), where oil is injected to cool the compressor and provide a seal for compression. 3. Oil is then removed in an oil separator with coalescers to 10 ppmw. 4. The compressed gas at 100 C is cooled to 40 C in the aftercooler. MR compression and heat rejection 5. Heat in the system is rejected in the oil cooler and aftercooler. 8

9 ecosmrt Process Visualisation Integrated MR precooling 1. The cooled, compressed MR enters the top of the PFHE where it is further cooled and partially condensed. 2. Partially condensed MR is separated into vapour and liquid fractions in the MR separator. 3. The liquid fraction is returned to the PFHE through an expansion valve at approximately 17 C. Integrated MR precooling 4. The vapour fraction passes through coalescers, reducing the oil content to 0.1 ppmw, before entering the PFHE. 5. The vapour fraction is then cooled as it passes through the top of the PFHE providing integrated precooling. 9

10 ecosmrt Process Visualisation LNG BOG reliquefaction 1. The vapour fraction passes through the PFHE and leaves as high pressure cryogenic liquid. 2. The cryogenic MR is returned to the bottom of the PFHE through the expansion valve and a flash separator at < 162 C. 3. As the cryogenic MR expands through the PFHE, it cools the high pressure MR as well as condensing the BOG. LNG BOG reliquefaction 4. The BOG condensate leaves the reliquefaction exchanger at 160 C and is sent back to the cargo tanks. 5. The warm MR is sent back to the compressor to close the circuit. 10

11 ecosmrt - Oil Carryover Management Typical MR system with precooling 4 ecosmrt with integrated precooling BOG after external precooling 10 C 2 MR after external precooling 10 C 3 Liquid MR to PFHE << 10 C 4 Top section of PFHE < 10 C 1 BOG to PFHE +40 C 2 MR after the aftercooler +40 C 3 Liquid SMR to PFHE +17 C 4 Top section of PFHE +35 C The higher temperature in the ecosmrt PFHE prevents oil freezing. 11

12 ecosmrt - Oil Carryover Management 10 ppmw oil <10 ppmw oil Condensation pulls down some dispersed oil into a combined liquid phase Approx. 0.1 ppmw oil enters the cryogenic portion of the process (acceptable, proven standard used with helium cryocoolers with oil-injected screw compressors) Gravity separation, integral coalescers, and low vapour pressure oil (<0.01 ppmw in the vapour phase) <10 ppmw oil 2-off 100% coalescers in series (1 active, 1 guard) During normal operation, oil contained in the liquid refrigerant is carried upwards through the exchanger and does not enter the cryogenic portion (stays > 0 C). But at turndown and shutdown it could fall downwards into the cryogenic section. ecosmrt has a solution for that 12

13 ecosmrt - Oil Carryover Management 10 ppmw oil <10 ppmw oil Condensation pulls down some dispersed oil into a combined liquid phase < 0.1 ppmw oil enters cryogenic portion of process (acceptable, proven standard used with helium cryocoolers with oilinjected screw compressors) Gravity separation, integral coalescers, and low vapour pressure oil (<0.01 ppmw in the vapour phase) <10 ppmw oil 2-off 100% coalescers in series (1 active, 1 guard) During normal operation, oil contained in the liquid refrigerant is carried upwards through the exchanger, and does not enter the cryogenic portion (stays > 0 C). But, at turndown and shutdown, it could fall downwards into the cryogenic section. A patent-pending feature of ecosmrt : external mixing of streams. Thermodynamically equivalent, but physically segregates oilcontaining streams from cryogenic parts of the process. 13

14 ecosmrt Main Equipment Selection Compressor selection criteria Positive displacement type Appropriate volumetric suction Good efficiency Robust and reliable design Good capacity control Good turndown capability Low maintenance Cryogenic heat exchanger selection criteria Multistream capability Able to handle flashing flow and condensation Compact design Robust and reliable design Good turndown capability Oil-injected Screw compressor Brazed aluminium plate-fin heat exchanger 14

15 ecosmrt - Plant Visualisation Length : 11,000 mm Width : 6,500 mm Height : 6,200 mm Weight : 65,000 kg 15

16 ecosmrt - Plant Visualisation 16

17 ecosmrt - Plant Visualisation 17

18 ecosmrt - Typical Application Range 180k LNGC with X-DF engines (BOG from FGC discharge) ecosmrt SMR17 13 kt ship speed 11.5 kt ship speed Anchoring (fuel gas) Anchoring (HFO) Excess BOG = 1558 kg/h Excess BOG = 1884kg/h Excess BOG = 2480 kg/h Excess BOG = 3080 kg/h Reliq capacity = 1.5 tph COP = 23.1% Reliq capacity = 1.9 tph COP = 23.1% Reliq capacity = 2.3 tph COP = 22.2% Reliq capacity = 3.1 tph COP = 21.9% 18

19 ecosmrt - Standard Range 19

20 ecosmrt - Performance Comparison (ME-GI SMR tph) ecosmrt Delivers Up To 35% More Reliquefaction Capacity per kw absorbed power 20

21 ecosmrt - Part-load Efficiencies (ecosmrt SMR tph) Power Requirements Slide Valve vs VFD Slide valve Built-in capacity control Simple operation Lower capital cost (included as standard) Lower efficiency at turndown (higher power consumption) Variable Frequency Drive (VFD) Additional equipment required Additional capital cost Increased electrical system complexity Higher efficiency at turndown (lower power consumption) 21

22 ecosmrt - Additional Operation Features Gas chromatograph sampling for initial MR fill and controlling automatic refrigerant top-up to maintain optimal plant performance Optional Bently Nevada condition monitoring for MR compressor set Heat tracing for winter operation down to 10 C Optional Variable Frequency Drive (VFD) can be incorporated to improve performance at part loads 22

23 ecosmrt Conclusion ecosmrt - the new improved MR reliquefaction plant for today s modern LNG Carrier offering increased performance with reduced power consumption, smaller footprint in a range of sizes to cover specific owner requirements. Contact: Andrew G. Scott, General Manager andrew.g.scott@babcockinternational.com Mobile: +44 (0)

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