Natural Gas Heating Research Articles

Solar driven polygeneration system for power, desalination and cooling

This paper presents a thermodynamic study of a polygeneration system combining Solar Power System (SPS), Multi Effect Desalination (MED) system and Absorption Refrigeration System (ARS). The plant is powered by solar energy with a backup natural gas heater. SPS includes a parabolic Trough Collector (PTC) field with thermal oil working fluid and steam Rankine cycle. A detailed simulation of a plant that can serve 1000 residential houses is developed. The analysis is performed using MATLAB package and its graphical user interface (GUI) tool. A parametric study is carried out to investigate effects of the different design and operating parameters on the plant energetic and exergetic parameters. Moreover, an economic evaluation is conducted to evaluate CAPEX, OPEX and unit product water/cooling costs. Results reveal that the highest exergy loss was found to occur in PTC solar field with about 82.42% of the plant exergy destruction. Moreover, the minimum PTC area can be achieved through the selection of the units (ARS, MED and SPS) capacities depending on steam condenser flow rate. In addition, the highest OPEX and total costs percentage (87.68% and 54.83%) are due to the natural gas heater. The proposed integrated system provides the lowest unit water price (1.247 $/m3), unit cooling price (0.003 $/kW hr) and the highest exergetic efficiency (23.95%) compared to the single and dual-purpose ARS/MED systems.

The winter choke: Coal-Fired heating, air pollution, and mortality in China

China’s coal-fired winter heating systems generate large amounts of hazardous emissions that significantly deteriorate air quality. Exploiting regression discontinuity designs based on the exact starting dates of winter heating across different cities, we estimate the contemporaneous impact of winter heating on air pollution and health. We find that turning on the winter heating system increased the weekly Air Quality Index by 36% and caused 14% increase in mortality rate. This implies that a 10-point increase in the weekly Air Quality Index causes a 2.2% increase in overall mortality. People in poor and rural areas are particularly affected by the rapid deterioration in air quality; this implies that the health impact of air pollution may be mitigated by improved socio-economic conditions. Exploratory cost-benefit analysis suggests that replacing coal with natural gas for heating can improve social welfare.

The status of household heating in northern China: a field survey in towns and villages.

Household heating in China has been ignored in the formulation of national energy plans until concerns with severe air pollution emerged. The government has started to implement the clean heating with ambitious targets. However, the specific heating status is not clear, especially in rural areas, thus leading to significant obstacles to policy formulation and air pollution control. In order to understand the current heating conditions and heating behaviors of households in more detail, we conduct a field survey of household heating in towns and villages across northern China from December 2017 to March 2018. The survey results show that more than 75% of rural households still rely on traditional heating methods, such as coal, firewood, kang, and a simple stove. Household income, awareness of using heating fuels, and government subsidies may have a certain impact on heating fuel choice. In addition, approximately 34.6% of rural households do not use any housing insulation measures, which is also of concern when focusing on the heating quality. Lastly, considering the huge cost of rural household clean energy transition, we suggest that only a few regions are encouraged to turn to electricity or natural gas for heating, while most other regions transition to using clean coal and attach more importance to improving the quality of heating stoves.

Robust Operation of a Water-Energy Nexus: A Multi-Energy Perspective

Due to the continuous development of renewable energy as well as the emerging high-efficiency energy conversion techniques, the interdependencies among the heterogenous energy systems, such as power, natural gas, and district heating, are strengthening, which gradually forms the concept of integrated energy systems (IESs) and has drawn much attention from academia and industry. However, few research efforts have been spent on analyzing the interdependencies between IESs and the water distribution system (WDS), especially in the operation time scale, though water is one of the most necessary materials during energy production and conversion. In this article, a robust operation model for the water-energy nexus against the uncertainties of wind generation outputs is proposed to explore the interdependency between the IES and the WDS. The overall model is a two-stage program with a nonlinear program (NLP) in each decision stages, owing to the ubiquitous pressure-flow equations as well as the on/off switching of device operation status. Further, a two-step solution procedure is devised to obtain a solution with good quality, including the mixed integer second-order program based approximation for the original NLPs and the convex optimization based feasibility recovery, which is further embedded into the traditional column-and-constraint generation algorithm to generate a robust solution. Simulation results validate the necessity and the effectiveness of the proposed model and methods.

Indoor Particle Concentrations, Size Distributions, and Exposures in Middle Eastern Microenvironments

There is limited research on indoor air quality in the Middle East. In this study, concentrations and size distributions of indoor particles were measured in eight Jordanian dwellings during the winter and summer. Supplemental measurements of selected gaseous pollutants were also conducted. Indoor cooking, heating via the combustion of natural gas and kerosene, and tobacco/shisha smoking were associated with significant increases in the concentrations of ultrafine, fine, and coarse particles. Particle number (PN) and particle mass (PM) size distributions varied with the different indoor emission sources and among the eight dwellings. Natural gas cooking and natural gas or kerosene heaters were associated with PN concentrations on the order of 100,000 to 400,000 cm−3 and PM2.5 concentrations often in the range of 10 to 150 µg/m3. Tobacco and shisha (waterpipe or hookah) smoking, the latter of which is common in Jordan, were found to be strong emitters of indoor ultrafine and fine particles in the dwellings. Non-combustion cooking activities emitted comparably less PN and PM2.5. Indoor cooking and combustion processes were also found to increase concentrations of carbon monoxide, nitrogen dioxide, and volatile organic compounds. In general, concentrations of indoor particles were lower during the summer compared to the winter. In the absence of indoor activities, indoor PN and PM2.5 concentrations were generally below 10,000 cm−3 and 30 µg/m3, respectively. Collectively, the results suggest that Jordanian indoor environments can be heavily polluted when compared to the surrounding outdoor atmosphere primarily due to the ubiquity of indoor combustion associated with cooking, heating, and smoking.

Gas Consumption Networks Development Problems

One of the urgent problems of housing construction modern development is the use of gas-powered equipment on natural gas for heating, hot water supply and food preparation. To solve this problem, Government Decree No. 1314 of December 30, 2013 is in effect in the territory of the Russian Federation The article sets out two options for the contractual obligations execution between the gas distribution organization and the applicant to connect to the gas distribution network of the capital construction object. As a result of the study, it was shown that the proposed measures, which allow to analyze the perspective connection to the gas distribution network and are aimed at reducing additional construction and installation works in the future, will help to increase the gas consumption networks development and reduce their connection times.

Comparison of carbon capture system and concentrated solar power in natural gas combined cycle: Exergetic and exergoenvironmental analyses

Two emissions mitigation systems, as CO2 capture and storage (CCS) and concentrated solar power (CSP) have been investigated to a power plant based on exergetic and exergoenvironmental analyses. A base plant of natural gas combined cycle for power production is taken as case study. The CSP technology used is parabolic trough collector (PTC) with two storage tanks. The environmental impact indicator used is the eco-indicator 99. The outcomes indicate that the natural gas heater exchanger should have its exergy destruction reduced to improve the performance of all system. The CCS plant reduced the net power and the PTC plant increased slightly the net power in relation to the base plant. The specific environmental impact of CCS plant was increased and of PTC plant was slightly decreased. The environmental impact of fuel production is the main environmental burden in the environmental performance. Therefore, the PTC system is the best case of mitigation system. Discussions about further improvements have been proposed.

Evaluation of technology, economics and emissions impacts of community-scale bioenergy systems for a forest-based community in Ontario

Biomass is often considered as an alternative to fossil heating fuels such as oil and propane but is rarely considered to displace lower cost natural gas. Using a case study approach, options for utilizing local forest biomass to reduce emissions related to natural gas heating are evaluated. The options considered include heat-only biomass boilers to fuel district heating networks, combined heat and power (CHP) connected to district networks and a microgrid or the provincial grid and production of renewable natural gas (RNG). The systems are evaluated in terms of technology readiness, break-even heat cost and GHG reduction potential. Other factors that could improve competitiveness, such as carbon pricing and low carbon fuel policies, are discussed. The systems that utilize a district heating network were found to be lower cost than RNG-producing systems, despite the need for significant infrastructure investment. While conversion of forest biomass to RNG results in a significantly higher heat cost than biomass district energy scenarios, these prices are competitive with other RNG technologies utilizing other feedstocks. The CO2 abatement cost for some DH and CHP scenarios was found to be lower than that of producing electricity using solar photovoltaic and wind power technologies in Ontario.

Assessment of potential alternatives for improving environmental trouser jeans manufacturing performance in Brazil

Abstract: Brazil features prominently in the world’s textile industry due to its know-how in cotton cultivation. However, the denim production chain generates relevant environmental impacts due to some characteristics of its production chain. This study investigated the usefulness of actions for improving environmental – measured in terms of Climate Changes (CC) –, and energy performances, represented by Primary Energy Demand (PED), to be implemented in the supply chain of trouser jeans produced in Brazil. A diagnosis of the current process provided by Life Cycle Assessment (LCA) indicated CO2 (liming and mechanization) and N2O (N-fertilizer) emissions in cotton cultivation, and CH4 and CO2 (natural gas) releases from heat for the industrial branch as CC impact sources. Reliance on natural gas (heat supply) industrial processes and the BR grid (energy supply) provided PED contributions. With a view of improving this performance, scenarios based on cotton and yarn imports, and even trouser jeans themselves from the United States, as well as the replacement of natural gas for wood have been proposed. The LCA for such conditions did not offers a unanimous alternative. The lesser impact for CC (4.44 kg CO2eq/FU) refers to the manufacture of trouser jeans in Brazil using wood as a heat source. An Integrated Analysis combined the effects of both analyzed dimensions for all the different scenarios and the same alternative achieved the best combined indicator Moreover, if the CC estimate takes into account CO2 fixation from the air and biogenic CO2 emissions, the use of wood becomes advisable. The current scenario kept the best energy outcomes (124 MJ/FU) given a performance in terms of utilities and transport. Moreover, Sensitivity and Trend Analyzes sought to magnify the effects of the parameter oscillations that integrate the analyzed systems models. Overlap areas among scenarios were identified, confirming that measures to reduce consumptions along the trouser productive cycle are necessary to achieve satisfactory results in terms of environmental and energy performance.

Research Inside a Gas Heating Device with Different Heat Transfer Medium

Natural gas heating device occupies an important position in natural gas industry, and the most widely used one is the cylindrical heating device with heat transfer medium. The key factors affecting the thermal efficiency of the cylinder gas heating device with heat transfer medium are the type of heat transfer medium and the flow field organization. In order to study the influencing factors of thermal efficiency of the heating device, a visualized practical gas heating device experiment system was established, and a two-dimensional heat transfer model fitting the real object was established, too. The unstructured fitting mesh was used to divide the physical model, and the finite volume method was used for discrete solution, while discrete coordinate (DO) radiation model is used to solve radiation equation. In this paper, water and ethylene glycol are used as heat transfer media to simulate and measure the heat flow field in the cylinder. The results show that ethylene glycol can broaden the application range of gas heating device. Under the same experimental conditions, the heat efficiency of the heating device with ethylene glycol as heat transfer medium is at least 3.8% higher than that of the heating device with water as heat heat transfer medium. The thermal efficiency of gas heating devices is generally less than 87%.

Techno-economic analysis of geothermal system in residential building in Memphis, Tennessee

The residential building sector in the United States relies prolifically on electric cooling and natural gas heating, ventilating, and air conditioning systems. Technology advancement for more energy efficient and cost-effective energy systems is continuous, and a geothermal energy system is an attractive alternative to electricity and natural gas. This study investigates a simulated residential building in Memphis, Tennessee (TN) to assess the energy savings by replacing the existing electric/gas system with a geothermal heat pump system. Further, economics are considered to examine the payoff period and ultimate viability for geothermal technology in this region. EnergyPlus™, the U.S. Department of Energy (DOE) whole building simulation engine, analyzed a prototype home in Memphis, TN with this common utility system. City-specific ground characteristics are used to customize the ground heat exchanger and optimize result accuracy. Simulations reveal that replacing the existing system with a geothermal system accomplishes a 26% reduction in energy use. Our results prove an exciting alternative for homes in Memphis, TN to achieve abundant energy savings. Despite lower meter readings, a homeowner must consider initial capital investment and payoff period. This study provides city-customized payoff data by using local ground characteristics for design, location-specific home features, and regional plus federal incentive programs. Methods used within create a unique and accurate template procedure for identifying promising regions for residential geothermal systems throughout the broader United States.

Multicriteria Analysis for Retrofitting of Natural Gas Melting and Heating Furnaces for Sustainable Manufacturing and Industry 4.0

Abstract Different retrofitting measures can be implemented at different levels of the industrial furnace, such as refractory layers, energy recovery solutions, new burners and fuel types, and monitoring and control systems. However, there is a high level of uncertainty about the possible implications of integrating new technologies, not only in the furnace but also on the upstream and downstream processes. In this regard, there is a lack of holistic approaches to design the optimal system configurations under a multicriteria perspective, especially when innovative technologies and multi-sectorial processes are involved. The present work proposes a holistic approach to natural gas melting and heating furnaces in energy-intensive industries. A multicriteria analysis, based on criteria and subcriteria, is applied to select the most profitable retrofitting solution using the analytic hierarchy process and stakeholder expertise. The methodology is based on technical indicators, i.e., life cycle assessment, life cycle cost, and thermoeconomic analysis, for evaluating the current state of existing natural gas furnaces. Once the current state is characterized, the methodology determines the potential of efficiency improvement, environmental impact reduction, and cost-savings caused mainly by the implementation of new retrofitting solutions including new refractories, new burner concepts (co-firing), and innovative energy recovery solutions based on phase change materials. Therefore, this methodology can be considered as the first stage that guarantees technical, environmental, and economic feasibility in evaluating the effects of new technologies on the overall system performance.

The study of a novel two-stage combined rankine cycle utilizing cold energy of liquefied natural gas

In order to save energy and protect the environment, the cold energy of liquefied natural gas and industrial waste heat are utilized in the Rankine cycle. In this study, a novel two-stage Rankine cycle that combines the advantages of the cascade two-stage Rankine cycle, parallel two-stage Rankine cycle, and regenerative Rankine cycle was proposed, in which the cold energy of LNG is utilized step by step. Ethane + R32, ethane + propylene, R23 + propylene, and R23 + R32 are selected as the working fluid combinations. The performance of working fluid is compared by studying the cycle performance under different parameters, and the cycle parameters are optimized through a genetic algorithm. The results show that Ethane + R32 is the best combination, with a higher exergy and thermal efficiency in most cases; further, ethane + propylene achieved the maximum exergy and thermal efficiency of 31% and 20.8%, respectively. When the temperature of the heat source is changed from 303 K to 323 K, the exergy efficiency of the cycle varies by approximately 16%. Compared with the parallel two-stage Rankine cycle + direct expansion cycle and the cascade two-stage Rankine cycle + direct expansion cycle, the exergy efficiency of the novel cycle increases by 104% and 29.76%, respectively.

Fuzzy Coordination Control Strategy and Thermohydraulic Dynamics Modeling of a Natural Gas Heating System for In Situ Soil Thermal Remediation

Soil contamination remains a global problem. Among the different kinds of remediation technologies, in situ soil thermal remediation has attracted great attention in the environmental field, representing a potential remedial alternative for contaminated soils. Soils need to be heated to a high temperature in thermal remediation, which requires a large amount of energy. For the natural gas heating system in thermal remediation, a fuzzy coordination control strategy and thermohydraulic dynamics model have been proposed in this paper. In order to demonstrate the superiority of the strategy, the other three traditional control strategies are introduced. Analysis of the temperature rise and energy consumption of soils under different control strategies were conducted. The results showed that the energy consumption of fuzzy coordination control strategy is reduced by 33.9% compared to that of the traditional control strategy I, constant natural gas flow and excess air ratio. Further, compared to the traditional control strategy II, constant excess air ratio and desired outlet temperature of wells, the strategy proposed can reduce energy consumption by 48.7%. The results illustrate the superiority of the fuzzy coordination control strategy, and the strategy can greatly reduce energy consumption, thereby reducing the cost of in situ soil thermal remediation.

Assessment of improvement in the energy and exergy efficiency of the gas heat plant after the exhaust gas cooled down below the dew point and the use of recovered heat

The tendency to lower the temperature of boiler flue gas below the dew point temperature has increased and usually the energy efficiency is calculated within the boiler balance boundary. Because the recovered heat is commonly used outside the balance boundary the calculations of efficiency in the extended balance boundary are presented for boiler house. This paper presents a method of assessing the energy and exergy efficiency of a steam boiler house, in which the modernization that was carried out consisted of cooling the flue gas below the dew point and absorbing the recovered thermal power.The article does not present new technical solutions in the field of boiler house modernization and only discusses the way of accounting for the effects of such a measure.In the publication, the correct and simple indicator in the assessment of improvement of energy efficiency have been indicated. Recommendations are illustrated using the example of the settlement of savings made in a natural gas heating plant in a food industry factory, equipped with two steam fire tube boilers, with a combined capacity of 2 × 30 t/h. The article calculates the effects of modernization of this boiler house by calculating energy losses before 15.33% after modernization 0.98%, exergy losses before 66.68% after modernization 64.41%. Fuel costs savings after modernization were also specified 4,447,804 PLN/a calculated in accordance with the methodology indicated in the article and savings 2,433,444 PLN/a determined based on the balancing of the indications of meters of recovered and managed energy within the boiler house.

Optimal design and thermo-economic analysis of an integrated power generation system in natural gas pressure reduction stations

A massive amount of byproduct energy of natural gas including pressure and cold energy is released during the natural gas depressurization process in pressure reduction stations. In this paper, a novel integrated power generation system is proposed to make joint use of the byproduct energy in pressure reduction stations and low-grade heat. The integrated system consists of two subsystems: a natural gas expansion subsystem recovers the pressure energy of natural gas, an organic Rankine cycle subsystem retrieves the cold energy of natural gas and low-grade heat. A multi-objective optimization model which comprehensively considers the thermodynamic and economic performance of the proposed system is established. Optimal determination of key design parameters including intermediate temperature and minimum approach temperatures is investigated under different heat source conditions. Based on the optimization results, the thermo-economic analysis of the proposed system is conducted to give guidance for further optimization. The simulation result shows that there exhibit positive linear correlations between optimal intermediate temperature and minimum approach temperatures with heat source conditions. With the optimized parameters, the performance of the proposed system is enhanced compared to the separated natural gas expansion and organic Rankine cycle systems. Net power output and exergy efficiency are improved by 17.15% and 22.37%. The cost of electricity is reduced by 42.23%. This paper provides an efficient solution to retrieve the byproduct energy in pressure reduction stations as well as low-grade heat.

Grid-connected energy hubs in the coordinated multi-energy management based on day-ahead market framework

This paper presents the coordinated energy hubs energy management in different networks based on the cooperation of hubs in day-ahead (DA) markets. The proposed model connects the electrical, natural gas and district heating networks by considering the electrical, natural gas as the hub's input, and electrical and district heating energies for the output of hubs. In this study, combined heat and power (CHP) and electrical storage systems, boiler, electric vehicles (EVs) parking lot and renewable energy sources (RESs) are considered in the context of energy hubs. In the process, the linear coordinated energy management problem includes a single linear objective function that is aimed at maximizing hubs profit in the DA market while considering linear networks and hubs constraints. Moreover, this model is taken into account uncertainty in different loads, DA market energy price, RES output power, and EVs parameters. Hence, the proposed problem is formulated as a scenario-based stochastic model using Monte Carlo simulation (MCS) for scenario generating and the fast backward/forward scenario reduction method for scenario reducing. Finally, this model is applied to a test system in the GAMS software environment, and the capacity and validity of proposed hubs energy management are investigated. Finally, simulation results confirm the efficiency of the hub coordinated energy management in the DA market.

Integrated energy systems planning with electricity, heat and gas using particle swarm optimization

An integrated energy system combines the power grid, natural gas pipeline, district heating network, and renewable energy generation to enhance the integration of renewable energy and smooth the load demand profile. However, the system faces great uncertainty derived from flexible renewable generation and demand load, etc. This paper brought in the robust optimization theory, considered the wind power integration on the supply side and the load fluctuation on the demand side. It also combined the constraints coming from the power grid, natural gas pipeline and heating network. We constructed a multi-objective robust optimization model for integrated energy system, based on minimizing the fuel cost, the wind power curtailment and the variance of peak-valley electrical load on the end-user side, as the objection functions. To solve the global optimal solution of the model, particle swarm optimization algorithm is utilized because of its fast convergence speed. Tianjin was selected as an example to demonstrate the model. Results indicated that, in the scenario of government promoting electricity substitution, the ratios of energy conversion have been optimized. For instance, in recent years, the shares of outsourced electricity, power to heat, and gas to heat are gradually improved toward the optimization results (31.29%, 16.49%, 13.56%). However, the results also implied that the thermal power generation input-output in thermal power plants (heat to power) should be increased, and the ratio of generation from gas-fired units (gas to power) need to be steadily adjusted. The optimization results provide a good reference for the energy investment strategy.

EFFECTS OF ENERGY PRICES ON ENVIRONMENTAL POLLUTION: TESTING ENVIRONMENTAL KUZNETS CURVE FOR ALGERIA

The current study is primarily motivated in testing Environmental Kuznets Curve (EKC) framework by including energy prices along with output growth. In addition, the current study is also important for analyzing the impact of energy prices by testing the effects of three different fuel prices. They include crude oil prices, natural gas prices and heating oil. The data is gathered from the period of 1980-2017. The results of ARDL confirm that economic growth has a positive and significant impact on carbon emission in Algeria. On the other hand, all energy prices (oil prices, heating oil and natural gas prices) confirm a negative and significant impact on carbon emission in Algeria. The results of ARDL also confirm a presence of U-Shaped EKC curve in the Algeria. The results VDM have confirm a bi-directional causal relationship between oil prices and carbon emission, however we found a unidirectional causal relationship from heating oil prices to carbon emission and no causal relationship between natural gas prices and carbon emission in Algeria.Keywords: Oil prices, natural gas prices, heating oil prices, Algeria.JEL Classification: E31, Q5, Q56DOI: https://doi.org/10.32479/ijeep.8312

Optimal scheduling of real multi‐carrier energy storage system with hydrogen‐based vehicle applications

In response to the challenge of improving energy utilising efficiency, multi-carrier energy storage systems, composed of electrical power networks, natural gas networks, heating networks, and other energy networks, are attracting more attention and developing rapidly in recent years. Traditionally, different energy infrastructures are commonly planned and operated independently, which results in less efficient energy usage and resource wasting. Through integrating as multi-carrier energy storage system, different energy infrastructures can be coupled and optimised as one unit. Here, an optimal scheduling for a real multi-carrier energy storage system with hydrogen-based vehicle applications is proposed from an economic point of view. Simulation results suggest the proposed optimal scheduling can help quantify the daily operation cost and achieve considerably operation cost saving by reasonably arranging and utilising all the components in the system.