System Configuration Design Research Articles

General integration method for system configuration of organic Rankine cycle based on stage-wise concept

Organic Rankine Cycle (ORC) integrated systems with heat sources consist of heat exchange processes and thermodynamic power conversion processes. Fully exploring feasible system configuration while considering fluid selection is crucial for enhancing ORC power generation and balancing economic costs. This study innovatively proposes a theoretical framework that decomposes the Rankine cycle into basic thermodynamic processes. The design of system configuration is regarded as the adjustment of the series-parallel relationships of these basic processes, aiming to achieve simultaneous optimization of the cycle structure and the HEN structure, thereby greatly expanded the search space for feasible ORC system configurations. The optimization problem is solved using a bi-level strategy, The outer layer determines the number of thermal power conversion components, operating parameters, and working fluid selection, then provides the associated stream information to the inner layer for optimizing the heat exchange scheme. Applying this method to two different case studies from the literature validated its effectiveness in optimizing scenarios with single and complex heat sources. The Pareto frontier obtained under the conditions of Case I indicates that the investment cost can be reduced by $33.04 k/yr while maintaining the same net power output. In exchange for an increase of $1.51 k/yr in investment cost, the maximum net power output can be improved by 124.74 kW. Under the conditions of Case II, the maximum net output power can increase by 9.71 %–52.5 %, and the Pareto frontier featuring outputs exceeding 50 kW is provided. By analyzing the relative positions of literature schemes and Pareto front within the solution space, the impact of system configuration improvements on the objective functions is explained. These results confirm the effectiveness of the proposed approach for designing optimal ORC energy recovery systems for heat sources. This contribution advances optimization methods for similar closed cycle configurations, which is significant for advancing the utilization of waste heat and addressing sustainability challenges.

Conceptual design of a novel 10 MW T-Semi floating offshore wind turbine and mooring system for transitional water depths

ABSTRACT A novel semi-submersible concept called T-Semi, along with several mooring systems designs, for a 10-MW FOWT is proposed and applied at a water depth of 60 m, to address the challenges of deploying floating offshore wind turbines (FOWTs) in transitional water depths. Comprehensive analyses were performed to analyze the performance of this innovative concept, including (a) intact and damaged stability; (b) frequency-domain hydrodynamic behaviour of the T-Semi floater; (c) different mooring system design configurations tailored for the T-Semi FOWT. The results demonstrate robust stability characteristics of the T-Semi floater and its favourable motion dynamics in heave and pitch. Additionally, the mooring system well satisfies the requirements of motion natural periods and safefy based on relevant international standards. In terms of the mooring design, the nonlinearity of the horizontal restoring force could be weakened by increasing the clump mass and decreasing the angle between mooring lines in a redundant arrangement.

Aerodynamic/control integrated optimization method for unpowered high-speed vehicle configuration design

The unpowered high-speed vehicle experiences a significant coupling between the disciplines of aerodynamics and control due to its characteristics of high flight speed and extensive maneuverability within large airspace. The conventional aircraft conceptual design process follows a sequential design approach, and there is an artificial separation between the disciplines of aerodynamics and control, neglecting the coupling effects arising from their interaction. As a result, this design process often requires extensive iterations over long periods when applied to high-speed vehicles, and may not be able to effectively achieve the desired design objectives. To enhance the overall performance and design efficiency of high-speed vehicles, this study integrates the concept of Active Control Technology (ACT) from modern aircraft into the philosophy of aerodynamic/control integrated optimization. Two integrated optimization strategies, with differences in coupling granularity, have been developed. Subsequently, these strategies are put into action on a biconical vehicle that operates at Mach 5. The results reveal that the comprehensive performance of the synthesis optimal model derived from the aerodynamic/control integrated optimization strategy is improved by 31.76% and 28.29% respectively compared to the base model under high-speed conditions, demonstrating the feasibility and effectiveness of the method and optimization strategies employed. Moreover, in comparison to the single-stage strategy, the multi-stage strategy takes into deeper consideration the impact of control capacity. As a result, the control performance of the synthesis optimal model derived from the multi-stage strategy improves by 13.99%, whereas the single-stage strategy only achieves a 5.79% improvement. This method enables a fruitful interaction between aerodynamic configuration design and control system design, leading to enhanced overall performance and design efficiency. Furthermore, it improves the controllability of high-speed vehicles, mitigating the risk of mission failure resulting from an ineffective control system.

Design space investigations of scramjet engines using reduced-order modeling

Conceptual design studies performed with reduced-order approaches allow feasibility and sizing considerations of air-breathing engines to be configured at an affordable computational cost. The present study is devoted to exploring the design space of a dual-mode ramjet engine operating in scramjet mode by means of reduced-order analysis to assess the effects of propulsive system design configurations on component level and overall performance characteristics. The approach proposed in this work combines axisymmetric flow configuration used for the design of supersonic/hypersonic intakes and solutions of one-dimensional flow governing equations coupled with finite-rate chemistry and thermophysical properties tables in the numerical domains of the combustor and nozzle components. The scramjet design space is generated by varying parameters which are flight Mach number and altitude, intake truncation angle, intake exit Mach number and equivalence ratio. Performance outputs of total pressure recovery factor, compression ratio, captured air mass flow rate, intake startability index, thrust, specific impulse, fuel consumption and overall efficiency are computed for each design scenario. The generated database is visualized via performance maps and analyzed in terms of propulsive characteristics. A feature importance study is also conducted to quantify the effects of design parameters on the propulsive performance.

NanoSMAD – A First Order System Configuration Design Tool for Nano and Micro Satellites

The emergence of nano and micro satellites, which weigh less than 100 kg, is causing a significant transformation in the space industry. The existing Space Mission Analysis and Design (SMAD) tools, which are primarily designed for larger satellites, often become irrelevant for these smaller satellites in terms of spacecraft mass, power, pointing requirement, total mission duration, fault tolerance, and design cost. To address this, we have developed a web based nanoSMAD tool specifically for designers of nano and micro satellites. This tool utilizes a comprehensive database of approximately 140 nano and micro satellites along with their internal subsystem specifications. By using the nanoSMAD tool, designers can efficiently develop nano and micro satellite systems by entering their requirements, which then generates high-level system design and requirement specifications. This process enables the tool to provide a basic satellite configuration design and generates a Master Equipment List (MEL) of subsystems. To further customize the design, users can provide more specific parameter inputs or select components from a drop-down menu, resulting in an iterative custom design approach. The satellite database used by the nanoSMAD tool is regularly updated through online surveys, including web scraping, to gather information on the latest non-space-grade off-the-shelf nano and micro satellite subsystems. This ensures that the tool stays up-to-date with the newest advancements in the field. Additionally, the nanoSMAD tool offers a unique feature of verifying the electrical interface compatibility of subsystems, which is an innovative aspect of the tool. Novice small satellite communities will greatly benefit from the nanoSMAD tool as it seamlessly generates an initial nano and micro satellite system design, providing a first-order understanding of the satellite’s configuration and requirements.

Research on the design of animation design System based on visual communication

In order to scientifically solve the problems existing in the application of traditional advertising animation design, researchers put forward to optimize the advertising animation design system with visual communication as the core in their research, which can not only solve the problems existing in the traditional visual communication design, but also provide multiple application functions for the system users. In this paper, on the basis of understanding the visual communication technology and the research status of the animation design system, using IE8-Chromel mainstream controller, image encoder, processing chip, etc., to optimize the hardware structure of the advertising animation design system configuration, gradually improve the advertising animation remote design processing port, to ensure the stability and effectiveness of the system operation. At the same time, according to the principle of visual communication, the steps of advertising animation design are simplified, the three-dimensional coordinates of advertising animation are accurately calculated, and the advertising animation is effectively designed. The final results show that the advertising animation design system with visual communication as the core has a high smoothness, which meets the needs of practical research.

Customized Product Configuration Rule Intelligent Extraction and Dynamic Updating Method Based on the Least Recently Used Dynamic Decision Tree

Abstract In the traditional customized product (CP) configuration design system, the configuration rules in the database usually rely on the manual input and maintenance of experienced designers. In complex product design, configuration rules are numerous, complex, and difficult to understand. The way of human input based on experience consumes plenty of resources, which are strictly limited by experienced designers. This overreliance on those experienced designers has seriously restricted the development of enterprises. To address this problem, a least recently used dynamic decision tree (LRU-DDT) algorithm for CP configuration rule intelligent extraction and dynamic updating is put forward in this article. Based on the decision table majority (DTM) classifier, the condition attributes are first reduced. An improved J48 decision tree algorithm is proposed to extract the CP configuration rules. In addition, the CP configuration rules can be dynamically updated based on LRU-DDT. To verify the proposed method, the GB10 high-speed elevator configuration design process is taken as an example. The configuration rules are extracted and updated by the proposed algorithms. The results show that the configuration solution efficiency is improved by 16%.

Modelling of the effects of luminaire installation geometries and other factors on road illumination system photometric parameters and energy efficiency

PurposeProperly planned road illumination systems are collectively a public wealth and the commissioning of such systems may require extensive planning, simulation and testing. The purpose of this simulative work is to offer a simple approach to facilitate luminance-based road lighting calculations that can be easier to comprehend and apply to practical designing problems when compared to complex multi-objective algorithms and other convoluted simulative techniques.Design/methodology/approachRoad illumination systems were photometrically simulated with a created model in a validated software platform for specified system design configurations involving high-pressure sodium (HPS) and light-emitting diode (LED) luminaires. Multiple regression analyses were conducted with the simulatively obtained data set to propound a linear model of estimating average luminance, overall uniformity of luminance and energy efficiency of lighting installations, and the simulatively obtained data set was used to explore luminaire power–road surface average luminance characteristics for common geometric design configurations involving HPS and LED luminaires, and four categories of road surfaces.FindingsThe six linear equations of the propounded linear model were found to be well-fitted with their corresponding observation sets. Moreover, it was found that the luminaire power–road surface average luminance characteristics were well-fitted with linear trendlines and the increment in road surface average luminance level per watt increment of luminaire power was marginally higher for LEDs.Originality/valueThis neoteric approach of estimating road surface luminance parameters and energy efficiency of lighting installations, and the compendia of luminaire power–road surface average luminance characteristics offer new insights that can prove to be very useful for practical purposes.

Availability Optimization Decision Support Design System for Different Repairable n-Stage Mixed Systems

This study attempts to propose an availability optimization decision support design system for repairable n-stage mixed systems, in which different combinations of subsystems, such as parallel, standby, and k-out-of-q, are connected in series configuration. The enumeration method, tabu search, simulated annealing, non-equilibrium simulated annealing, and the modified redundancy allocation heuristic combined with a modified genetic algorithm will be proposed to solve the system availability optimization problem and further determine the appropriate system configuration design. Several simulated cases are conducted by following the procedural flow of the proposed availability optimization decision support design system to reach the optimal allocations of the component redundancy amount, the optimal repair rates, and the optimal failure rates of all subsystems to minimize the total system cost under several configuration constraints for different repairable n-stage mixed systems. Simulated results display that the proposed availability optimization decision support design system can definitely take advantage of different component redundancy system designs, including the parallel-series system, n-stage standby system, n-stage k-out-of-q system, and n-stage mixed system, to save a lot of cost and meet the high level of the system availability requirement compared to the n-stage single component series system. Additionally, the results for all proposed combined methods also show that the parallel-series system can obviously reach the same level of system availability requirement with less system total cost, in contrast to the n-stage standby system, by presuming the identical deteriorating probability for both the operating components and the standby components. The performance comparisons of five proposed combined methods for four proposed system configurations are analyzed comprehensively. It can be concluded that the performances of the modified redundancy allocation heuristic method, combined with a modified genetic algorithm on the criteria of the optimal system costs for four proposed system configurations, are not only superior to the other four combined methods, but also to the performances on the criteria of CPU running time for four proposed system configurations.

Heat storage in solar adsorption refrigeration systems: A case study for indigenous fruits preservation

The present study deals with heat storage in a solar-powered refrigeration system designed for indigenous products preservation in a cold room with a positive temperature. One of the key goals of this study is to show the importance of heat storage and the choice of the suitable coupling, position, and technology of thermal heat storage in these systems to ensure energy management and system operation flexibility. A new system configuration design where the direct connection between the solar collectors and the adsorption chiller used in the directly driven chiller without any heat storage module and in the classic storing system is suppressed and a new special regulation system is added to manage the temperature of the supplied water to the adsorption chiller. Under the same solar collectors' area, the new configuration design performs well than the existing configurations and offers more flexibility and stability to the system. It was found that, the heat storage, performed by a Hot Water Tank (HWT), enhances the system's cooling production time duration as well as offers stability and reduces the highly fluctuant hot water temperature in solar adsorption chillers. It's shown that the choice of the adsorption chiller cycle time duration is of great importance as well as the HWT volume on the system's performance. The study shows also that the system achieves better performances when considering a stratified HWT instead of a fully mixed HWT. Using a total solar collectors' area of 84.53 m2, a hot water tank of 3 m3, and a cycle time of 1200 s, a solar fraction of 86% is obtained when the proposed configuration is connected to the stratified heat storage technology however 80% is reached when the system is equipped with the mixed hot water tank.

Assessing the spatial and temporal variability of greenhouse gas emissions from different configurations of on-site wastewater treatment system using discrete and continuous gas flux measurement

Abstract. Global emissions linked to wastewater treatment are estimated to account for up to 1.5 % of total greenhouse gas (GHG) emissions globally. However, few studies have measured GHG emissions from domestic on-site treatment systems (DWWTSs) directly. In this study, two DWWTSs were monitored for 446 d and > 42 000 gas flux measurements were conducted using both discrete spot measurements and continuous flux chamber deployments. The observed GHG fluxes from biological activity in the soil and water phase were found to be highly spatially and temporally variable and correlated to environmental factors, water usage patterns and system design. In total, the results show that a septic tank discharging effluent into a well-designed soil treatment unit is estimated to emit a net 9.99 kg-CO2eq.cap-1yr-1, with approximately 63 %, 27 % and 10 % of the total CO2-equivalent net emissions in the form of CO2, CH4 and N2O, respectively. Emissions from the septic tank surface contributed over 50 % of total emissions and tended to be strongly underestimated by one-off discrete measurements, especially when episodic ebullitive events are to be considered. Fluxes from the soil treatment unit (STU) stemmed from both the soil surface and the vent system. Soil fluxes were mostly influenced by temperature but peaked regularly under conditions of rapidly changing soil water content. Vent fluxes were mostly governed by effluent, quality and a low number of high-emission events were responsible for the majority of total observed vent emissions. Owing to the strong overall spatial and temporal heterogeneity of observed fluxes from DWWTSs across all modules, future studies should focus on continuous deployments of a number of flux chambers over discrete measurements to accurately assess GHG emissions from on-site systems. This study also provided insights into managing GHG emissions from DWWTSs by different system configuration design, as well as indicating that the current IPCC emission factors for CH4 and N2O significantly overestimate emissions for on-site wastewater treatment systems.

Using Ultrasonic Reflection Resonance to Probe Stress Wave Velocity in Assemblies of Spherical Particles

A high-sensitivity method to measure acoustic wave speed in soils by analyzing the reflected ultrasonic signal from a resonating layered interface is proposed here. Specifically, an ultrasonic transducer which can be used to both transmit and receive signals is installed on a low-high acoustic-impedance layered structure of hard PVC and steel, which in turn is placed in contact with the soil deposit of interest. The acoustic impedance of the soil (the product of density and wave velocity) is deduced from analysis of the waves reflected back to the transducer. A system configuration design is enabled by developing an analytical model that correlates the objective wave speed with the measurable reflection coefficient spectrum. The physical viability of this testing approach is demonstrated by means of a one-dimensional compression device that probes the stress-dependence of compression wave velocity of different sizes of glass ballotini particles. Provided the ratio of the wavelength of the generated wave to the soil particle size is sufficiently large the data generated are in agreement with data obtained using conventional time-of-flight measurements. In principle, this high-sensitivity approach avoids the need for the wave to travel a long distance between multiple transmitter-receiver sensors as is typically the case in geophysical testing of soil. Therefore it is particularly suited to in-situ observation of soil properties in a highly compact setup, where only a single transducer is required. Furthermore, high spatial resolution of local measurements can be achieved, and the data are unaffected by wave attenuation as transmitted in soil.

Variable-Load Heat Pumps: Impact of the Design and Control Parameters on the Actual Operation Conditions

Nowadays heat pumps (HPs) represent the main alternative to traditional heating systems for the transition to nearly zero-energy buildings. Though HPs are a well-known technology, the estimation of their actual energy performance is still under discussion. Indeed, the proper choice of the HP design parameters (e.g. size, rated supply temperature) and the adopted control strategy can assume a paramount role to cover the mismatch between declared and actual performance of the system. Objective of this work is to analyze this mutual dependence in an operating system to provide guidelines for the design of a residential heating system with a HP. Through a dynamic energy simulation tool, a variable-load air-to-water HP is used to cover the thermal demand of a residential building. The effect of the reciprocal influence of different design choices (e.g. rated heating capacity or design supply temperature) and control strategies (e.g. climatic regulation) is analyzed by simulating different scenarios. To complete the evaluation, the impact of a thermal energy storage is also assessed. The study allows to identify guidelines for the design of different system configurations and results seem to confirm the impact of the investigated parameters on the seasonal performance of the system.

Thermodynamic performance analyses for CCHP system coupled with organic Rankine cycle and solar thermal utilization under a novel operation strategy

The combination of an organic Rankine cycle (ORC) and solar collector (ST) with combined cooling heating and power (CCHP) system has the potential to improve its thermodynamic performances. Therefore, in this paper, fully considering thermal cascade utilization, a novel CCHP system combining ORC and ST is proposed, which uses solar energy and exhaust heat as ORC driving heat sources. Compared with traditional CCHP and CCHP-ST systems, the advantages of the CCHP-ORC-ST system are demonstrated. A collaborative optimization method considering both system configuration optimization and operation strategy is proposed, which realizes the improvement of system energy efficiency and economy. Based on the collaborative optimization method, the CCHP system with different integrated configurations is applied to commercial and office buildings. Through parameter analysis, the effects of parameters (such as the rated capacity of internal combustion engine and ORC evaporation temperature, etc.) are discussed. The findings portrays that the cost per unit supply area of the CCHP-ORC-ST system in typical years of office and commercial buildings is about 19.8 $/m2 and 25.9 $/m2. Compared with the CCHP system, the cost-saving rates of the CCHP-ORC-ST system in commercial and office buildings increase by 15.0% and 27.0%, respectively. The CCHP-ORC-ST system can flexibly utilize ORC to generate more electricity, improving energy efficiency and reducing wasted heat. Consequently, the proposed CCHP-ORC-ST system based on the collaborative optimization method can determine the optimal system configuration and operation design for energy savings and consumption reduction.

Energy and exergy analysis of MSW-based IGCC power/polygeneration systems

Since municipal solid waste (MSW) is a negatively priced, abundant, and essentially renewable feedstock, energy recovered from MSW is a useful technology to reduce the consumption of fossil fuels, and also reduces the expenses needed to dispose of MSW. Three configurations of MSW-based IGCC power system (Design 1), MSW-based IGCC polygeneration system (Design 2), and CaO-based IGCC polygeneration system (Design 3) are proposed. Design 1 uses a combination of an identified MSW gasifier, an integrated intermittent chemical-loop air separation (IICLAS), and Rankine and Brayton cycles to generate electricity and achieve the high concentration of CO2 emissions around 93.3%~94.7%. The process for co-production of DME and MeOH in Design 2, which replaces the Rankine cycle in Design 1, could increase the net energy efficiency of Design 1 by 71.6%, but the total CO2 emissions from Design 2 are merely 7.97% of Design 1. The calcium looping gasification (CaLG) process in Design 3, which replaces the MSW gasifier in Design 2, could increase the production rate of DME of Design 2 by 12.5%. The CO2 concentration from the calcinator in Design 3 is higher than CO2 concentration in flue gas from Designs 1 and 2 by 2.0%~3.5%. Through exergy analysis, the overall exergy efficiency of Design 3 is lower than Designs 1 and 2 by 3.2%~10.1% due to the exergy destruction rate and ratio in the gasification zone of Design 3 higher than other designs. The GaLG process could increase the DME yield as well as the outlet CO2 concentration, but this approach design induces a higher exergy loss.

Architecting an MBSE Black-Box System Model for the Physical Layer of a Visible Light Intersatellite Communication System

Fast and reliable high-speed intersatellite communication (ISC) between small satellites is dependent on the physical layer (PL) design of the onboard communication system. However, as with nonlegacy systems, the lack of architecture and design information pertaining to the development of the PL of an LED-based visible light communication (VLC) system for ISC poses significant challenges to architecting the communication system. Addressing these challenges requires a holistic approach to the specification of the system design. To this end, we explore the use of model-based systems engineering (MBSE) principles in mitigating the design complexity of the PL architecture for the VLC system. Design concerns and gaps are addressed by developing an executable black-box system model that specifies the conceptual architecture of the system, and a parametric model that analyzes multiple system configurations based on generated values for the signal-to-noise ratio and bit error rate parameters. We utilize the structural, behavioral, and parametric semantics of SysML to define, specify, visualize, and analyze the various system design configurations. The resulting PL black-box system specification is verified through model execution.

An Intent-Based System Configuration Design for IT/NW Services with Functional and Quantitative Constraints

An Intent-Based System Configuration Design for IT/NW Services with Functional and Quantitative Constraints

Two-phase collaborative optimization and operation strategy for a new distributed energy system that combines multi-energy storage for a nearly zero energy community

The combination of a distributed energy system and multi-energy storage system has the potential to use renewable energy on a large scale and to further improve the system’s energy efficiency. Therefore, a new type of distributed energy system that combines multi-energy storage is proposed in this paper. Its novelty is that the three types of energy storage, i.e., cold, heat and electricity, are considered simultaneously, and the electric vehicle load is also included in the distributed energy system in combination with the multi-energy storage system, which allows full consideration of the effect of multi-energy storage on the distributed energy system. Three operation modes are proposed to give full play to the advantages of the new system according to the charging mode for electric vehicles. Subsequently, a two-phase collaborative optimization method for system configuration and operation optimization is proposed, and it is applied to a nearly zero energy community. The results show that the primary energy savings rate of the distributed energy system that combines multi-energy storage is 53.5% when the electric vehicle charging load is provided by the new system, which is 17.5% higher than that of the traditional distributed energy system, while the annual cost savings rate increased by only 8.3%. In addition, the hourly operating cost of the distributed energy system that combines multi-energy storage is also significantly reduced compared with the separated production system. Therefore, the method of two-phase collaborative optimization in the new system proposed in this paper can be used to realize the optimal system configuration and operation design for energy savings and consumption reduction. Finally, the new system can provide a feasible scheme for the energy supply of a nearly zero energy community in the future.

Vibration control by active integrated control system under bidirectional ground motions

To improve the safety and security of the structures with irregular plan configuration, the new torsionally effective passive control system (ICS) was first proposed by the author, which utilizes a new design configuration to dissipate the unwanted energy from the structures in the lateral and torsional directions. In this research, a new active structural control approach, which is the active form of the ICS (or active integrated control system, AICS), is introduced as an alternative active control system, especially for the buildings with torsional sensitivity. In the design of active system configurations, two actuators driven by the linear quadratic regulator (LQR) are implemented and used to apply the optimum control forces to the ATMDs and AICS. For examining the performance of the proposed system configuration, the final design is applied to the 9-story Benchmark steel structure subjected to bidirectional three historical earthquakes. The obtained results show the overall performance of structural performance by using the AICS is substantially improved as compared to conventional ones (ATMDs) under selected ground accelerations with a 3% to 6% improvement in the lateral directions and by nearly 20% in the torsional direction in terms of the peak and root mean square response reduction.

Natural gas liquefaction using the high-pressure potential in the gas transmission system

This article concerns natural gas liquefaction using high-pressure potential, which is available in pressure letdown stations. The article proposes an integration of a pressure letdown station with a natural gas liquefaction line which enables partial exergy recovery and decreasing natural resources consumption to produce LNG. Exergy recovery is carried out by a replacement of the pressure reduction valve by a turboexpander, which can recover exergy from high-pressure natural gas flowing through a pressure reduction stage. The recovered energy may be used to drive a natural gas liquefaction unit, coupled with the reduction station. A case study concerning an existing pressure letdown station includes two chosen model of a turboexpanders with low and high internal efficiency and several natural gas liquefaction units possible to integrate. The varying size of the liquefaction unit corresponds to a different degree of utilization of energy generated in the expander. Turboexpander produces electric power supplying the liquefaction unit, however, it requires the use of additional energy to heat the gas before the reduction stage, which increases the thermoecologic cost of natural gas transferred to distribution network. Energy, exergy and thermoecological cost analysis was carried out for three system design configurations and for six sizes of the liquefaction line with different turboexpander efficiency. The first configuration included a basic configuration with the pressure letdown station and the liquefaction unit, the second configuration also included an integration with a waste heat source (ICE exhaust gases), and the third configuration used multi-stage expansion. Energy efficiency of the integrated expansion-liquefaction system varies from 35.40% to 66.64%, while its exergy efficiency ranges from 15.75% to 46.33% depending on the size of the liquefaction unit and the gas liquefaction method. It was proved that it is possible to reduce thermo-ecological cost of LNG by 8.2%. Reducing raw material consumption needed for LNG production increases natural gas thermo-ecological cost by only 1%. A preliminary economic analysis based on prices of energy carriers was done. It was found that the boundary price was estimated at 0.0246 €/kWh for one of chosen systems.