Cryogenic Plant Research Articles

Calculation of Energy Parameters of LNG Power Plant with Utilization its Cold Energy

This paper proposes the possibility of using a cryogenic power plant as part of a hybrid engine, which can be used in the system of urban transport infrastructure. The model of this cryogenic power plant consists of main contour and auxiliary contour of power plants. The parameters of a hybrid cryogenic power plant were evaluated and the characteristics of the main contour of a hybrid power plant driven by a piston expander and a turbo expander with heat input from both the ambient and the exhaust gases of a diesel engine were calculated. Liquid methane is used as the main fuel. The optimal operation cycle of the auxiliary contour of power plant itself has been determined. For this purpose the main parameters of Rankin and Brayton cycles have been analyzed - consumption, power, efficiency. Besides, the most suitable cryogenic fuels for efficient operation were determined and the schemes of the plants were proposed. The calculations were performed using calculation algorithms, examples of which are presented in this article.

Commissioning Status of the Linac for the Facility for Rare Isotope Beams

The Facility for Rare Isotope Beams will be completed in late 2021. We report here on the current efforts to commission the first stages of the 200-MeV/u superconducting, continuous wave heavy-ion linac. The statuses of the cryogenic plant and its distribution system, the accelerator cryomodule commissioning and operations, the ion source and front end transport development, the radio-frequency quadrupole commissioning, and thenbeam dynamics development to support high-power operation are reviewed. Plans for commissioning the remainder of the linac systems are presented.

Energy polygeneration systems based on LNG-regasification: Comprehensive overview and techno-economic feasibility

Energy polygeneration systems offer an attractive solution to harness efficiently the premium-quality physical exergy contained in Liquefied Natural Gas (LNG) because of its cryogenic temperature. However, this exergetic potential is usually wasted when LNG is regasified.The first part of the paper provides a comprehensive overview regarding applications and technologies, global deployment and main bottlenecks and opportunities related with exergy recovery from LNG-regasification. The second part of the paper is focused on the modelling and techno-economic evaluation of a proposed polygeneration plant. This plant regasifies LNG and squeezes its physical exergy in cascade for the combined production of electric power and refrigeration at low and conventional temperatures. The system aims to increase the efficiency of existing cryogenic power plants but with a moderate additional complexity.The nameplate equivalent electricity of the polygeneration plant proposed is nearly 150 kWh/t-LNG, with an exergetic efficiency of 42%. As a reference, the annual emission of 40 thousand tons of greenhouse gases are avoided and the capital investment may be recovered in a period of 5 years. It is determined the critical impact of the capital cost and economic parameters such as electricity tariffs or carbon taxes on the economic feasibility of this plant.

Novel integrated structure of carbon dioxide liquefaction energy storage system using solar energy

Humans turned to use renewable energies by underground resource reduction and carbon dioxide emissions increase. One of the ways to reduce carbon dioxide and generate power at the consumption peak is using solar energy to compression and liquefaction of carbon dioxide. At the peak power consumption, the liquid carbon dioxide is gasified to generate power. In this article, a new integrated structure for carbon dioxide liquefaction to power generation using parabolic trough solar collectors is developed and analyzed. This process implements an absorption–compression refrigeration cycle that can generate refrigeration of 17.4 MW to liquefy carbon dioxide at -56 °C in the charging mode. In the discharge mode, a two-stage cryogenic ORC plant and a gas turbine power cycle produce 7.872 MW. This integrated structure has an electricity storage efficiency of 67.87% and a round-trip efficiency of 41.22%. Exergy analysis shows that total exergy efficiency and irreversibility are 83.84% and 2265 kW, respectively. HYSYS and TRNSYS software and MATLAB programming with the geographical conditions of Tehran in Iran are used to simulate the process. The economic analysis by the annualized costs of system method shows that the period of return and the prime cost of product are 5.12 years and 8.55 cents per kWh of electricity, respectively. Finally, the effects of the drastic parameters on the performance of the process are studied investigated.

Novel cryogenic argon recovery from the air separation unit integrated with LNG regasification and CO2 transcritical power cycle

Two novel air separation units at cryogenic temperature were proposed to reach high purity nitrogen, oxygen, and argon. The first process refers to a three-column cryogenic air separation plant without using an external refrigeration system. An integrated process including cryogenic air separation, combined-cycle power plants (e.g., transcritical CO2 cycle and gas turbine), and LNG regasification was presented and analyzed as the second process to produce liquid oxygen and vaporize LNG without using external refrigeration source. Results of the first proposed process demonstrate that the specific energy consumption of high purity nitrogen, oxygen, and argon reduces to 18.7%, 13%, and 12% respectively when compared with the conventional processes. Specific energy consumptions and exergy efficiency for the second plant improved by nearly 33% and 16% in comparison with the first process. Also, the gas turbine and CO2 power cycle efficiencies were almost 35% and 45% in the second process. Exergy analysis on both systems demonstrated that expansion valve V-2 (99.42%), high-pressure distillation columns (99.41%), and argon recovery section (98.34%) have the lowest irreversibility and highest exergy efficiency. Meanwhile, the highest exergy destructions in the first and second proposed plants belong to the low-pressure distillation tower of the first process and the combustion chamber of the second process with around 3400 kW and 24,000 kW respectively.

Low-pressure supersonic separator with finishing adsorption: Higher exergy efficiency in air pre-purification for cryogenic fractionation

Air fractionation in cryogenic plants demands a Pre-Purification Unit for air compression and removal of water, carbon dioxide and trace-species. The conventional Pre-Purification Unit – FULL-TSA – adopts temperature-swing adsorption (TSA) with an activated-alumina bed for dehumidification followed by a molecular-sieve bed removing carbon dioxide and trace-species. A novel scheme – SS-TSA – prescribes a Supersonic Separator abating ≈98.5% of moisture followed by a small single-bed molecular-sieve removing remaining impurities. SS-TSA-HI is a SS-TSA variant allocating compression heat for molecular-sieve regeneration. This work compares thermodynamic performances of FULL-TSA, SS-TSA and SS-TSA-HI via exergy analyses and discloses better utilization of resources. Exergy analyses are supported by HYSYS simulator running with unit-operation extensions for calculating the phase-equilibrium sound speed and simulating the supersonic separator. Since exergy rates depend on Reference Environmental Reservoirs, two Reference formalisms are employed at 1 atm and 25 °C. Reference#1 prescribes air with 60% relative humidity (the raw air feed), while Reference#2 adopts water-saturated air. It is shown that Reference#1 is appropriate for overall system analysis, while Reference#2 is better for sub-systems analysis as it dramatically lowers cooling-water exergy flows. SS-TSA has 61% less exergy losses than FULL-TSA in the purification step as the supersonic separator accomplishes bulk dehumidification drastically reducing steam and nitrogen for bed regeneration. Reference#1 exergy efficiencies of FULL-TSA, SS-TSA and SS-TSA-HI attained 57.9%, 60.0%, and 60.3%, respectively.

The dynamic synthesis time-lag control for the 1.3 GHz LCLS-II Cryomodule test at Fermilab

The 1.3GHz LCLS-II Cryomodule (CM) has 8 cavities and each cavity has 9 RF cells and 80W heater. The 1.3GHz LCLS-II CM is 12.2-meter-long and contains a total 241.3 liters (equivalent liquid) of liquid helium, which is filling up by the 4KW@2.0K cryogenic plant at the Fermilab Cryomodule Test Facility (CMTF). The dynamic synthesis 2K cryogenic control system is built to control the long time-lag, unstable CM cryogenic system, under different modes operations. A report on the results obtained from the dynamic synthesis long time-lag control in the CMTF 1.3GHz CM test will be presented.

Cryogenic Upgrade of the Helium Central Liquefier and Superconducting Cable & Wire Test Facilities at CERN

The demand for liquid helium (LHe) for users at CERN without dedicated cryogenic infrastructure is set to increase due to future projects and experiments in the Antiproton Decelerator. LHe is supplied to the users by means of 500 liter dewars filled by the central liquefier (B165) that comprises a cryogenic plant of 400 W @ 4.5 K. In addition, the Superconducting Cable & Wire Test Facility (B163) located nearby will be upgraded to incorporate the forthcoming installation of the new test station FRESCA 2. B163 includes a second cryogenic plant of 400 W @ 4.5 K and a dedicated cryogenic distribution system. To maximize the production of the two cryogenic plants and their ancillary infrastructure, thus improving the subsequent distribution of LHe, a combined cryogenic distribution system has been developed. This system will increase the LHe storage capacity; allow the direct transfer of helium inventory between both facilities and the gravity filling of large capacity trailer dewars in addition to the 500 liter dewar fleet. This paper details the architecture of the new cryogenic distribution system, the analysis undertaken to define it, the design and specifications of the various components and the schedule of the realization of the project.

Cryogenic System for Shanghai Synchrotron Radiation Facility

The Shanghai Synchrotron Radiation Facility (SSRF) is an intermediate energy light source built at Zhang-Jiang Hi-Tech Park in Shanghai, China. The RF power and voltage required for storing the electron beam are provided by means of three SC (superconducting) cryomodules, each containing one 500 MHz superconducting cavity. A cryogenic plant with cooling capacity of 650 W at 4,5 K (herein called SSRF-I cryoplant) supplied by Air Liquide advanced Technologies has been in operation since August of 2008 to provide cooling for the three superconducting cavities.In order to further improve the performance of SSRF, the following SC devices are to be applied for the SSRF upgrade (SSRF-II):1) 2 harmonic SRF (superconducting radio frequency) cavities with 1,5 GHz will run alternatively at 2 K (31 mbar).2) One superconducting wiggler is to be used for one of the new-built beam lines, ultra-hard multi-functional beam line. The SC wiggler will be cooled by cryocoolers at 4,2 K region.To support the operation of the new cavities, AL-aT (Air Liquide advanced Technologies) has designed, manufactured and started a new cryogenic system including a 2K system with equivalent cooling capacity of at least 650 W at 4,5 K and 60 W at 2K. The system is mainly constituted of a refrigerator HELIAL MF, an auxiliary 2 K cold box and of a 2 K warm pumping station.This cryogenic unit has been started successfully at the end of 2018 and has proven performances both at 4,5K and at 2K.

The ESS Test and Instruments Cryoplant – First test results and operation experiences

The European Spallation Source (ESS) is a neutron-scattering facility being built with extensive international collaboration in Lund, Sweden. The world’s most powerful linear proton accelerator shoots protons against a rotating tungsten target where neutrons are knocked off (“spallate”) and are guided to the neutron instrument suites. Three cryogenic plants and a vast cryogenic distribution system serve the cooling needs of the superconducting RF cavities in the accelerator, the cold hydrogen moderators in the target, a cryomodule test stand and the sample environments for neutron instruments. The project’s demand of schedule and economic feasibility requires a high degree of parallel work for installation and commissioning of the cryogenic and auxiliary systems. The first of the three plants, the Test and Instrumentation Cryoplant (TICP) has been installed, commissioned and acceptance tested in 2018 by Air Liquide Advanced Technologies (ALAT). The plant consists not only of a standard compressor system and coldbox but also of a process vacuum system for 2K operation, internal and external helium purifiers, liquid helium tank, filling and boil of station and a helium recovery system. It is heavily integrated in the overall cryogenic installations at ESS. The paper describes some project challenges, acceptance test results and first operation experience.

FRIB cryogenic system status

The Facility for Rare Isotope Beams (FRIB) cryogenic plant has been successfully commissioned, including compressor system, 4.5 K cold box system, sub-atmospheric (2 K) cold box system, and the distribution system for two of the three linear accelerator (Linacs) segments. This plant uses the Ganni-Floating pressure process, allowing the compressor discharge and 4.5 K cold box supply pressure to automatically vary from 6 to 21 bar, without introducing additional exergetic losses to reduce the capacity (e.g., throttling turbine inlet valves, load heaters, etc.). The 2 K (31 mbar) load is supported using five stages of centrifugal compressors, housed within the sub-atmospheric cold box, which recompress the helium to 1.15 bar (and around 30 K). In 2012, FRIB assumed the responsibility, in collaboration with JLab to design and procure the sub-systems after the decision to move away from an industry supplied turn-key system. FRIB was responsible for procurement of all systems, all onsite activities, including the installation and integration of all the subsystems, development of the control systems, as well as, the integration, commissioning, and testing of each sub-system. At present this has culminated in the production of the first beam through the first Linac segment. An overview of the planning and execution of the project will be presented, which allowed meeting of scheduled goals and anticipated performance, and prevented the need to store or ‘double-handle’ any equipment.

Implications and Methodology of Retrofits in Cryogenic Plants

Developments over the past few years allow Linde Kryotechnik to economically replace the turbines of a cryogenic plant with state-of-the-art technology leading to several advantages. Stand out among others are higher efficiency of the turbines, easier operation of the plant, increased reliability and an update of the design point regarding current customer demands which improve the overall performance and efficiency of an upgraded cryogenic system. While each retrofit is unique based on the customer demands and situation, it is still possible to follow a certain methodology. Several successful retrofits with conclusions are presented.

Simcryogenics: a Library to Simulate and Optimize Cryoplant and Cryodistribution Dynamics

In many fields of engineering, conception and operation teams need to perform simulations in order to design systems fulfilling the user requirements and to operate the systems efficiently. To simulate a cryogenic plant and its distribution to the end-users, a large number of commercial or homemade tools are nowadays available. However, there is a lack of available solutions for rapid dynamic simulations either for control with model-based design and for design optimization through parametric studies. This article presents the Simcryogenics library that has been developed at the CEA Cryogenic Engineering Department for several years. This library aims at generating model-based control schemes for cryogenic plants that are subject to high disturbances (such as the pulsed heat loads in fusion reactors or particle accelerators). The library is based on Simscape, the modelling language extension of the Matlab/Simulink software suite, which is very flexible and well documented. This paper introduces how Simcryogenics works, how to use it as well as it provides examples of applications such as the modelling of warm compression stations and cold boxes, the simulation of the cooling of superconducting magnets and RF cavities, the generation of control schemes.

Helium Management of ESS Cryoplants with Common Safety Relief Header and Recovery System

The European Spallation Source (ESS) is a neutron-scattering facility being built with extensive international collaboration in Lund, Sweden. Three cryogenic plants with a vast cryogenic distribution system meet the cooling requirements of the superconducting RF cavities in the accelerator (ACCP), the cold hydrogen moderators in the target (TMCP), a cryomodule test stand and the sample environments for neutron instruments (TICP). The first of the three plants, the TICP has been successfully installed, commissioned and acceptance tested in 2018 by Air Liquide Advanced Technologies. Meanwhile the other two cryoplants (ACCP and TMCP) are under commissioning and testing by Linde Kryotechnik AG. The cryoplants share common helium buffer tanks, safety relief headers and helium recovery system due to historical, economical and architectural reasons. The helium recovery strategy and system configuration will be described in the paper. Resulting challenges, risks and safety relevant events that happened during, especially parallel, commissioning activities will be presented. The measures implemented to mitigate major risk and lessons learned are addressed as well.

Status of the LCLS-II Cryogenic Distribution System

The LINAC Coherent Light Source II (LCLS-II) located at SLAC National Accelerator Laboratory (SLAC) in Menlo Park, CA, is a U.S. Department of Energy project tasked to design and build a world-class x-ray free-electron laser facility for scientific research. The Linac has superconducting radio frequency cryomodules that are connected to the cryogenic plant by the Cryogenic Distribution System (CDS), which consists of distribution boxes with heat exchangers and reliefs, feed caps, end caps, and surface, vertical, and bypass transfer lines. The CDS components were designed and built to specification by industry. The components have been delivered and their installation at SLAC will be discussed. The as-built relief system design will be presented, showing minimization of relief inlet pressure drops while meeting capacity requirements. The relieving flow pressure drops along the lengths of the CDS to centrally located reliefs at the distribution box were analysed to satisfy Pressure Vessel and Process Piping Code criteria to ensure relief performance. The sub-atmospheric 2 K circuit relieving approach will be discussed, which includes a three-way diverter isolation valve suitable for sub-atmospheric service. The component anchoring load design approach and installation into concrete floor will be discussed. This addresses loading, including seismic loading, along the component’s load path to floor anchoring system.

Experience from the outsourcing of the Cryogenic Operation & Maintenance at CERN

CERN operates and maintains several large cryogenic systems including those serving the LHC complex and its associated detectors, together with cryogenic Test Facilities and distribution services. Outsourcing of Operation and Maintenance to an industrial partner was implemented in 2016. It allows the cryogenics group to activate different level of services starting from basic technical support up to full delegation with result oriented obligations for availability and helium inventory management by means of dedicated contractual key performance indicators. After almost three years from the implementation of this complex service contract in a context of intensive Operation & Maintenance campaigns of CERN accelerators, detectors and test facilities, this paper will report on the obtained results, emphasizing on technical, organizational and economic performance. Additionally the paper intents to share lessons learned from the implementation and follow-up of such major outsourcing. Finally the paper will describe the expected evolution of specific needs with respect to the provided services during the Long Shutdown 2 (2019-2020) of the CERN accelerators, detectors and test facilities, including the phase of resuming operation of the cryogenic plants and ancillary infrastructure.

Commissioning plan for LCLS II 2 K cold box

Commissioning of the LCLS II cryogenic plant has been planned with respect to electrical and mechanical systems checkout, equipment cleanup, cool-down, and individual performance evaluation. This plant consists of warm and cold storage, helium compressors, 4.5 K and 2 K cold boxes, and all auxiliaries typical for helium refrigeration processes. The 2 K cold box, consisting of five cold compressors in series to produce the flow and pressures necessary for 2K operation, will be the last equipment installed and, along with an additional 10,000 L helium dewar, will allow the entire plant to be commissioned as a single entity. The pre-commissioning stages, commissioning plan for 2 K cold box without connecting to the LCLS II LINAC, additional test equipment needed to simulate the loads, all process studies and associated results are described herein.

Cryogenic system design for the electron-ion collider at Brookhaven National Laboratory

Any upgrade of the Relativistic Heavy Ion Collider (RHIC) to an electron-ion collider (EIC) will involve large scale upgrades to the existing cryogenic infrastructure. The challenges to such a project at Brookhaven are unique because of the existing central cryogenic plant. The central plant is oversized for current RHIC operations and can handle the EIC’s heat loads comfortably. However, a lot of equipment will require 2 K cooling for which extra local cryogenic systems are needed. Any new systems will have to be designed to work in tandem with the existing RHIC cryogenic system. This places further constraints on the design of the system, with respect to the cryodistribution system. This study discusses the various baseline configurations for each local cryogenic system for the EIC upgrade.

Preliminary conceptual design of FCC-hh cryo-refrigerators: Air Liquide Study

In the framework of a world-wide international collaboration, the FCC-hh, a 100 TeV hadron collider in a 100-km long tunnel, is proposed as a future circular collider beyond LHC at CERN offering the broadest discovery potential at the energy frontier. For such high performance hadron collider, the cryogenic system has to distribute very large cooling capacities all along the 100-km tunnel for the superconducting magnets continuously cooled at 1.9 K and for the beam screens operated between 40 and 60 K. The required total cooling power will be produced in 10 refrigeration plants with a unit equivalent capacity of 100 kW at 4.5 K, up to 4 times larger than the present state-of-the-art. Half of the entropic refrigeration load is due to the synchrotron radiation produced by the high-energy proton beams and deposited on beam screens actively cooled around 50 K. This non-conventional thermal load distribution is an additional challenge for the FCC-hh cryogenic system. Furthermore, the cryogenic system has to cool down the cold mass of the FCC-hh machine in less than 20 days with controlled thermal gradients in the cryo-magnets and beam screens. Based on preliminary design works from research institutes, an engineering study was performed with world-leader industries to assess a preliminary conceptual design for the FCC-hh cryogenic plants with industrial solutions and innovative technologies. The present paper recalls the FCC-hh cryogenic requirements and presents the main results of Air Liquide study confirming the novel precooling refrigeration option down to 40 K.

Oilfree centrifugal electric compressor with foil gasdynamic bearings

The article gives the description of a highspeed oilfree electric compressor with foil gasdynamic bearings and a synchronous permanent magnet electric drive. During experiments, the refrigeration system has been optimized, and the total power of losses in the bearings and losses on the ventilation of the rotor has been measured. The tests were carried out in the vacuum regime at the inlet up to -0,5 bar; also the tests were performed in the generator regime. This compressor may be used as an independent electric one for air, gases, including refrigerants, and also as a compressor unit in the capacity of a part of a refrigeration or cryogenic plant. In generator mode, the compressor is applicable in waste heat recovery systems operating on the Organic Rankine Cycle (ORC).