Existing Heating System Research Articles

Economic and Environmental Analysis of Incorporating Geothermal District Heating System Combined with Radiant Floor Heating for Building Heat Supply in Sarein, Iran Using Building Information Modeling (BIM)

Despite the considerable breakthrough in district heating systems (DHS) globally, there is not yet any policy on developing this technology in Iran. This country has a high range of energy demand, while renewable energies play a minor role in its energy supply chain. Furthermore, the world is going through a transition towards renewable resources, which currently consist of only 10% of the total energy mix. As the first contribution in this area, this paper aims to design a 100% renewable DHS integrated with radiant floor heating for a group of residential buildings in Sarein, Iran. Moreover, the literature proposes a novel approach for combining geothermal energy and Municipal Solid Waste (MSW) to achieve a 100% renewable energy system. Building Information Modeling (BIM) is used for thermal analysis by 3D designing the buildings in SketchUp and OpenStudio and simulating the heat load in EnergyPlus. Three scenarios are presented to better compare the DHS with the decentralized heating system regarding fuel consumption, as well as environmental and economic aspects. The town’s existing heating system that consumes natural gas for both space heating and hot water demand is referred to as the IHS-G scenario. The DHS-G scenario represents an 87% renewable DHS system, working with natural gas and geothermal energy, while the DHS-MSW scenario is a 100% renewable system, consuming both geothermal energy and Municipal Solid Waste (MSW). Finally, findings suggest that DHS-MSW and DHS-G scenarios reduce the annual energy consumption of buildings by about 595 and 33 toes, respectively. Hence, the greenhouse gas effect will alleviate by mitigating the emission of 1403 and 1339 tons of CO2-eq./year, respectively. Moreover, exporting the extra natural gas through both LNG and pipeline provides about 26 million and 28 million USD/year revenue in DHS-G and DHS-MSW scenarios.

How Multi-Criterion Optimized Control Methods Improve Effectiveness of Multi-Zone Building Heating System Upgrading

This paper aims to develop multi-objective optimized control methods to improve the performance of retrofitting building heating systems in reducing consumed energy as well as providing comfortable temperature in a multi-zone building. While researchers evaluate various controllers in specific systems, providing a comprehensive controller for retrofitting the existing heating systems of multi-zone buildings is less investigated. A case study approach with a four-story residential building is simulated. The building energy consumption is modeled by EnergyPlus. The model is validated with energy data. Then, the building steam system model is upgraded, and in the other case, renewed by a hydronic system instead of a steam one. Three optimized controller groups are developed, including Model Predictive Controller (MPC), fuzzy controllers (Fuzzy Logic Controller (FLC) and an Optimized Fuzzy Sliding Mode Controller (OFSMC)), and optimized traditional ones. These controllers were applied to the upgraded steam and hydronic heating systems. The control methods affected the tuning of the boiler feed flow by regulating the condensing cycle and circulating the pump flow of the hydronic system. Accordingly, renewing the heating system improves energy efficiency by up to 29% by implementing a hydronic system instead of the steam one. The fuzzy controllers increased renewing effectiveness by providing comfortable temperatures and reducing building environmental footprints by up to 95% and 12%, respectively, compared with an on/off controller baseline.

Heat Pump Installation in Public Buildings: Savings and Environmental Benefits in Underserved Rural Areas

Heat pump technology offers a path towards reducing the use of fossil fuels to heat space, providing energy bill savings and reducing air pollution and GHG emissions. The choice of heating method is based on costs; hence, this study examines the gains from operating heat pump systems in public buildings as well as alternative systems using electricity, LPG, and heating oil. The study focuses on the Ruda-Huta municipality in Poland that, as is common in rural areas, lacks access to a district heating system or piped gas. The empirical analysis includes heat pump installations in eight municipal buildings. The study found that the use of ground source heat pumps proved competitive with existing heating systems in terms of payback time. Calculations for three heating energy source scenarios, i.e., electricity, LPG, and heating oil, used the Simple Pay Back Time (SPBT) and the Levelized Cost of Heat (LCOH) methods and the average prices of the three energy types for the period 2012–2021. The payback period calculations disregarded the EU subsidies for heating systems utilizing renewable energy sources (RES). The payback time for electric, LPG, and heating oil were, respectively, 6.7–7.8 years, 4.1–6.1 years, and 6.7–6.9 years. Much larger spreads favoring heat pumps were calculated using the LCOH, and the costs in the case of electric heating were nearly three times higher and doubled when using heating oil and LPG. The gains from investing in heat pump systems have been offset by the increase in electricity, LPH, and heating oil prices, which have been predicted to continue to increase in the foreseeable future supporting the use of heat pumps in rural areas lacking access to, for example, district heating systems. The switch to heat pumps reduced local air pollution by eliminating the burning of fossil fuels to heat space in public buildings.

Evaluation of Economic Benefits and Greenhouse Gas Emissions of Data Center Waste Heat for the Use of District Heating

As carbon neutrality emerges as a global challenge, the government announced the “Data Dam” as one of the ten major projects of the Korean New Deal. Accordingly, the number of data centers and the amount of power usage for equipment operation are expected to increase due to the acceleration of the data economy. In this study, the costs of existing heating systems and district heating systems using data center waste heat are compared according to the life cycle cost analysis using the payback period method. However, the payback period method has difficulty reflecting future value, so the value was complemented using the present value method. When the data center waste heat is used as district heating, assuming that the energy cost is frozen (scenario 1), the benefit is about KRW 4 billion for 1,000 households, and the investment cost recovery takes 18 years. On the other hand, if the energy cost goes up by 5% every five years from the start of the project (scenario 2), the resulting energy savings is about KRW 30 billion, and the time to recoup the initial investment is shortened by eight years. The study calculated greenhouse gas (GHG) emissions according to energy consumption for each scenario in accordance with the 2006 Intergovernmental Panel on Climate Change (IPCC) Guidelines. The results are 14.9 tCO₂-eq for scenario 1 and 0.006 tCO₂-eq for scenario 2 (a reduction of more than 99% in GHG emissions compared to scenario 1).

Sustainable heating system by infrared radiators

Maintaining the optimum temperature in the living quarters is the key to a comfortable stay. Due to the lack of a central heating system or in the event of its insufficiency, they resort to the installation of additional heat sources. There is a wide range of devices on the market with different operating principles, hence the difficulty of which is better - a convector or infrared heater. A comparative analysis of devices will help you make the right choice. Asking the question of which is better a convection heater or an infrared heater, one must decide on its role in heating the house. It is better to use them as additional equipment with an existing heating system. One of the effective sources of additional heating are infrared radiators. Its principle of operation is based on infrared radiation, which provides a quick and qualitative increase in temperature in any part of your apartment. Today, more and more people prefer infrared radiators. From the usual electric convector, they differ in that they heat not the air in the room, but hard surfaces (floors, walls) and objects, and these, in turn, leak heat into the surrounding space. So, the entire room is heated up unnoticeably.

Analysis of reliability indicators in the supply of thermal energy using geographic information systems

The analysis of existing heating systems in Russian cities was carried out. The predominant systems in most cities are centralized from CHPPs, industrial and district boiler houses. The functional structure of the city of Voronezh is analyzed - the system of centralized heat supply of the city is divided between different legal entities transfer of heat energy to consumers. The main problems of the city heat supply are considered. Proposed a set of measures to improve the efficiency of the heat supply of Voronezh, such as the introduction of an electronic model of heat supply of the city and the use of technical means to improve energy efficient mode of heating networks. Comparison of the existing available capacity of heat supply sources and perspective heat load in each of the allocated zones of sources was carried out.

Use of energy-efficient systems for ensuring the microclimate of the premises

The article considers the use of the WLHP system, which is an alternative to already existing heating systems. It allows you to streamline engineering networks and implement energy-saving measures in the heat consumption sector. The advantages of the system are noted and the use of a heat pump in the system is recommended for the disposal of excess heat in the premises in order to reduce heat consumption. Measures related to energy-efficient technologies in Poland, Germany, and Sweden, including the use of heat pumps, were considered. The information regarding of the measurements СОР of energy-saving equipment implemented in Ukraine, in accordance with current standards, with the aim of improving the quality characteristics of the equipment present in the WLHP system, was introduced. The advantages of such a solution in comparison with traditional systems for ensuring the microclimate of premises are noted.

Energy and economic sustainability in the renewal of centralized heating systems using hybrid heat pump systems

In the context of the energy transition policies desired by the EU, the objectives set by 2030 include the reduction of greenhouse gas emissions, the achievement of greater energy savings and the increase in the use of renewable energy. This study, after an analysis concerning the Italian building stock, aims to highlight a possible first step towards achieving these objectives: the renewal of centralized heating systems in multi-dwelling buildings. In fact, on the national scenario there are about 430,000 condominiums with centralized heating system built before 1990 and, therefore, possibly liable to energy efficiency. In this research a case study building was simulated using the software EnergyPlus in which a renovation of the existing heating system was modelled in the Matlab/Simulink environment with an innovative hybrid generator consisting of an air/water heat pump and a condensing boiler. The analysis of this solution, carried out for three different Italian climatic zones, highlights how significant reductions in CO2 emissions can be achieved, high energy savings in terms of primary energy use and savings regarding usage costs, thus achieving greater comfort and sustainability. In addition, an economic analysis was carried out comparing different combinations of systems with the aim of identifying the best solution for each application.

Review of Research on System Thermal Inertia Modelling and Optimal Scheduling from the Perspective of Flexible Resources

The thermal inertia of the existing heating system is often considered an adverse factor, which will affect the operation of the system. However, under the perspective of resource flexibility, the thermal inertia of the system can effectively increase the flexibility of the system operation, significantly reduce the energy consumption and enhance the ability of energy supply and demand balance, and enhance the new energy integration, such as the wind power. Based on the flexible resources, it focuses on the study of the thermal inertia of the “network side” heating pipe network of the system and the optimal scheduling of the heating system. Combined with the thermal inertia of the pipe network, the operation characteristics of the power/heat output of the gas-steam combined cycle unit were analysed theoretically. On this basis, the optimal scheduling model of the system was established. Taking the energy supply system of an industrial park as an example, the model was verified to achieve a more stable power output effect of the unit.

Performance Comparison of CPC based solar installations at different locations in India and analysis of variation pattern

Currently the industrial heat demand is met by using expensive fossil fuels. Exclusive use of solar energy is not feasible due to the fluctuating pattern of solar radiation intensity. Solar hybridization with the existing heating system can be an appropriate solution to meet the process heat requirement of many industries. Concentrator Solar Thermal (CST) technologies can generate the medium temperature heat required for industrial processes. The present study was undertaken with an objective of comparing and analyzing the designed performance of the solar fields using the Compound Parabolic Concentrator (CPC) technology against the actual measured performance values for boiler feed water preheating application at two different locations in India. The optical efficiency of the CPC collector, 64.8%, obtained when tested as per part 5 of IS 16648:2017 was used for designing the solar fields as per the daily heat requirement. The performance of the installations at both the locations was monitored for a period of five months. The observed variation in the performance of each installation than the designed performance was compared and analyzed for the causes. The average variation in designed and measured performance was in the range of 9.0% to 9.8% for location 1 and 2 respectively, attributing to heat rejection from the collector attachments and fluid transfer lines, dust effect on the absorber and reflector of CPC, instrument’s uncertainty, other losses due to shadow effect, vacuum loss from the tubes, dislocation of tubes, heat removal and usage pattern etc. The reasons of the losses from both the fields were of the similar nature, which should be taken into account to design a solar thermal system to achieve predicted performance near to the designed performance. Preheating of boiler feed water is one of the potential applications of solar CPC technology.

Optimal Sizing of a Grid Independent Renewable Heating System for Building Decarbonisation

As the use of fossil fuels has led to global climate change due to global warming, most countries are aiming to reduce greenhouse gas emissions through the application of renewable energies. Due to the distributed and seasonal heating demand, the decarbonisation of heating is more challenging, especially for countries that are cold in winters. Electrically powered heat pumps are considered as an attractive solution for decarbonising heating sector. Since grid-powered heat pumps may significantly increase the power demand of the grid, this paper considers using local renewable energy to provide power for heat pumps, which is known as the grid independent renewable heating system including photovoltaic, wind turbine, battery storage system and thermal energy storage. This paper investigates a complete renewable heating system (RHS) framework and sizing the components to decarbonise building heating. The relationship between the reduction of gas consumption and the requirement of battery storage system (BSS) under the corresponding installation capacity of renewable components is analysed with their technical requirements. Then, according to different investment plans, this paper uses the particle swarm optimisation algorithm for optimal sizing of each component in the RHS to find a solution to minimise CO2 emissions. The results verify that the RHS with optimal sizing can minimise CO2 emissions and reduce the operational cost of natural gas. This work provides a feasible solution of how to invest the RHS to replace the existing heating system based on gas boilers and CHPs.

Evaluation of Modular Solid Oxide Fuel Cell Systems for Providing Resiliency to Data Centers and Other Critical Power Users

Aris Energy Solutions, LLC and its project partners, Gaia Energy Research Institute (Gaia), the National Energy Technology Laboratory, the University of West Virginia, Velocity Data Centers, and the National Aeronautics and Space Administration are installing and testing next-generation, modular SOFC systems at data centers, and Gaia is spearheading the effort to independently analyze the engineering and economic performance of these systems, benchmarked against DOE’s performance and price compression goals. This work develops thermodynamic and techno-economic analyses (TEA) for these modular SOFC systems and initially focuses on identifying cost drivers critical to their R&D and commercialization path.Approach:Gaia completes a TEA based on experimentally-measured test data from the installed SOFC systems. Gaia collaborates with the project Team to identify and analyze cell, stack, and system engineering performance data. Gaia then develops and deploys custom computer models and data sets that include, but are not limited to, design for manufacture and assembly (DFMA) models of the modular SOFC systems. This TEA includes detailed cell and stack costs, costs of balance of plant (BOP) components, capital costs, operating and maintenance costs (fixed and variable), and sensitivity analyses. Modelling results initially focus on identifying primary cost drivers.Results:Modelling results indicate that the primary cost drivers for the lifecycle costs of these modular SOFC systems include, but are not limited to,(1) the system’s ramp rate (i.e. the system’s ability to change its electric power output up and down per unit time);(2) the in-use, experimentally-measured electrical efficiencies of the stack, BOP subsystem components, and overall system;(3) the system’s availability (i.e. the percentage of time that the system is up and running)(4) the power density of the stack;(5) the capital costs of the stack;(6) the capital costs of the surrounding BOP subsystems;(7) the quantity of effective, in-use heat recovery when operated in combined heat and power (CHP) mode.Regarding (1), when connected to data centers and to the electricity grid, these SOFC systems need to have the ability to rapidly increase or decrease their electrical power output. The modular SOFC systems tested here have been specifically designed with a high degree of electrical ramping capability over a high turn-down ratio. In a data center, this fast-ramping capability enables the modular SOFC systems to more closely follow the data center’s load, which is the most valuable end-use of the electricity, while limiting electricity exported to the grid, which is typically less lucrative and highly dependent on regional legislation that impacts a distributed generator’s access to sell back electricity to the grid and the ‘sell back price.’Regarding (2), historically, the actual, measured in-use electrical efficiencies of stationary fuel cell systems installed in the field have strayed substantially from manufacturer specifications. The extent of this discrepancy has varied substantially, depending on the specific manufacturer, the cell technology, operating conditions, the usage profile, the age of the system, and other factors. Yet, the lifecycle costs are heavily influenced by this actual, measured in-use electrical efficiency; this variable encapsulates the quantity of natural gas/ energy consumed vs. the quantity of electricity produced. The value proposition of these systems is heavily determined by this efficiency, combined with the spark spread, or the difference between the natural gas purchase price and the price / value of the otherwise displaced electricity.Regarding (3), electricity at data centers and other critical power users demands a financial premium, in part due to an expectation of increased uptime (or reduced downtime) of the electricity supplied. To warrant this financial premium, the SOFC systems must demonstrate a high availability, defined as the percentage of time that the system is able to remain up and running at or above its baseline engineering performance standards (including, for example, its electrical efficiency, its electrical power output, etc.)Regarding (4), (5), and (6), primary cost drivers for the modular SOFC systems also include stack capital costs, stack power density, and system BOP costs. Over time, stack capital costs are estimated to decline more rapidly with more high-volume manufacture, compared with BOP capital costs, because the BOP already incorporates many mass-produced components.Regarding (7), these modular SOFC systems are also unique in that they can supply their waste heat at high enough temperatures to be useful for space and hot water heating in most U.S. and European buildings. Unlike other modular fuel cell predecessors, these SOFC systems can integrate well with the existing heating systems of most buildings, based on their heat supply temperatures and the heat demand temperatures prevalent in most building types. Figure 1

Heat Load Numerical Prediction for District Heating System Operational Control

Abstract To develop an advanced control of thermal energy supply for domestic heating, a number of new challenges need to be solved, such as the emerging need to plan operation in accordance with an energy market-based environment. However, to move towards this goal, it is necessary to develop forecasting tools for short- and long-term planning, taking into account data about the operation of existing heating systems. The paper considers the real operational parameters of five different heating networks in Latvia over a period of five years. The application of regression analysis for heating load dependency on ambient temperature results in the formulation of normalized slope for the regression curves of the studied systems. The value of this parameter, the normalized slope, allows describing the performance of particular heating systems. Moreover, a heat load forecasting approach is presented by an application of multiple regression methods. This short-term (day-ahead) forecasting tool is tested on data from a relatively small district heating system with an average load of 20 MW at ambient temperature of 0 °C. The deviations of the actual heat load demand from the one forecasted with various training data set sizes and polynomial orders are evaluated for two testing periods in January of 2018. Forecast accuracy is assessed by two parameters – mean absolute percentage error and normalized mean bias error.

Decarbonization of a district heating system with a combination of solar heat and bioenergy: A techno-economic case study in the Northern European context

We study the role of solar heat in decarbonization of a Nordic district heating (DH) network, where most of the annual heat demand is satisfied with bioenergy. We use actual data from a Finnish municipality to create a dynamic model of the heating system with Apros® simulation software. With the help of modelling, we examine various decarbonization scenarios for the existing heating system, using different combinations solar thermal collectors, thermal energy storage (TES) and limitations on how and when solar heat can access the system. According to results, zero emissions during the summer can be achieved with annual solar share of 13.2% and at 44 €/MWh levelized cost of heat (LCoH), if the integration is supported by TES and a careful planning of solar heat integration. Our results show that a simple approach of pursuing for a maximal solar share does not necessarily lead to a reduction in carbon emission or in LCoH. In fact, aiming at higher solar shares of 15–25% in our case system, actually increase greenhouse gas emissions compared to the base case. This highlights the importance of focusing on emissions reductions instead of simple addition of renewable energy when DH utilities plan for solar heat investments.

Study of novel solar assisted heating system

The potential for energy, carbon dioxide equivalent (CO2e) and cost savings when using low emissivity (low-ε) transpired solar collectors (TSCs), combined with heat pumps in a range of configurations, has been investigated using computer modelling. Low-ε TSCs consist of metal solar collector plates with a spectrally sensitive surface, perforated with holes. Ambient air is drawn through the holes and heated by convection from the solar collector plate, increasing the air temperature by up to 25 K. The heated air can be used for e.g. space heating, or pre-heating water in buildings. The models developed have been used to compare the performance of low-ε TSC/heat pump heating systems in small and large buildings, at a range of locations. The model results showed savings in energy, CO2e and costs of up to 16.4% when using low-ε TSCs combined with an exhaust air heat pump compared with using the exhaust air heat pump alone. Practical application: If the UK is to meet its target of reaching net zero greenhouse gas emissions by 2050, it will be necessary to adopt low or zero carbon heating technologies. The novel low emissivity transpired solar collector device investigated can contribute to this. Its advantages include: (i) utilising solar radiation; (ii) readily integrated with existing heating systems e.g. heat pumps; (iii) significant energy, CO2e emissions and cost savings; (iv) low cost device; (v) minimal energy input i.e. one small fan; (vi) can be retrofitted to existing buildings; (vii) its benefits were applicable at all of the (wide range of) locations tested.

Techno-economic performances of clean heating solutions to replace raw coal for heating in Northern rural China

The combustion of raw coal leads to severe environmental pollution; however, many people in Northern rural China still use coal as a primary heat source. How to select clean heating technologies that can replace raw coal is essential, but still unclear; therefore, it is crucial to evaluate the existing heating systems to find out the answer. Herein, we selected four possible substitution solutions, including shaped coal heating boiler, biomass pellet heating boiler, low ambient temperature air-to-water heat pump, and low ambient temperature air-to-air heat pump, to conduct field tests and compare with raw coal as the baseline. We assessed the indoor air temperature, energy conservation effect, environmental impact, and economic impact of these solutions. Results indicated that biomass pellet for heating and low ambient temperature air-to-air heat pump possess the potential for dissemination. Herein, the biomass pellet heating boiler is the best solution in rural areas with rich biomass resources, while the low ambient temperature air-to-air heat pump is deemed suitable in rural areas that lack access to biomass or have flexible heating demands. This study evaluated the possible clean heating solutions in Northern rural China, which might be useful for other countries facing similar environmental problems.

Automatic estimation of clothing insulation rate and metabolic rate for dynamic thermal comfort assessment

Existing heating, ventilation, and air-conditioning systems have difficulties in considering occupants’ dynamic thermal needs, thus resulting in overheating or overcooling with huge energy waste. This situation emphasizes the importance of occupant-oriented microclimate control where dynamic individual thermal comfort assessment is the key. Therefore, in this paper, a vision-based approach to estimate individual clothing insulation rate ( $$I_{\rm{cl}}$$ ) and metabolic rate (M), the two critical factors to assess personal thermal comfort level, is proposed. Specifically, with a thermal camera as the input source, a convolutional neural network (CNN) is implemented to recognize an occupant’s clothes type and activity type simultaneously. The clothes type then helps to differentiate the skin region from the clothing-covered region, allowing to calculate the skin temperature and the clothes temperature. With the two recognized types and the two computed temperatures, $$I_{\rm{cl}}$$ and M can be estimated effectively. In the experimental phase, a novel thermal dataset is introduced, which allows evaluations of the CNN-based recognizer module, the skin and clothes temperatures acquisition module, as well as the $$I_{\rm{cl}}$$ and M estimation module, proving the effectiveness and automation of the proposed approach.

Techno-economic and environmental aspects of solar driven heating assistance options for residential buildings

In this study, storage of sensible heat, hydrogen and electricity is compared in four different systems to be integrated to existing heating systems utilising solar energy for heating assistance. V...

Hybrid System Combining Ice-Phobic Coating and Electrothermal Heating for Wing Ice Protection

In-flight icing for aircraft is a large concern for all those involved in aircraft operations. Generally, an electric heater has been used to prevent in-flight icing. A hybrid anti-icing system combining ice-phobic coating and electrothermal heating (ICE-WIPS) has been proposed by the Japan Aerospace Exploration Agency (JAXA) to reduce the power consumption in the heating unit. In order to validate the effectiveness of ICE-WIPS, validation and demonstration tests are conducted using icing wind tunnels at the Kanagawa Institute of Technology (KAIT) and at the Icing Research Tunnel in the NASA Glenn Research Center. Using a NACA0012 airfoil as a test model, ICE-WIPS demonstrates substantial reduction in power consumption as compared to the existing heating system. The reduction depends on the in-flight icing conditions; more than a 70% reduction is achieved at a liquid-water content (LWC) of 0.6 g/m3 and a median-volume diameter (MVD) of 15 μm at 75 m/s with zero angle of attack. In wet-icing conditions, more than a 30% reduction in power is achieved.

Indoor Climate Modelling and Economic Analysis Regarding the Energetic Rehabilitation of a Church

Background: The aim of our study was to identify an optimal heating system for the analyzed church. We also evaluated the energy consumption of the existing system and of those proposed in order to choose the best heating system. Methods: We analyzed the current existing heating system, a mixed system (static heaters and hot air heating) in a Romanian heritage church, build in the 16th century, and we compared it with an underfloor heating system that has been mentioned in the literature as an alternative for church heating. We used a computational fluid dynamics (CFD) analysis of the indoor climate with two turbulence models (k-ε and k-ω). Results: Comparing the two heating systems through boxplot graphs, we could highlight pertinent conclusions regarding the temperatures and velocities of the measured air currents. Thus, of all the heating systems, the underfloor heating had the lowest temperatures, but the highest air velocities, in the churchgoers area, especially under the towers zone. Conclusions: We observed that the underfloor heating system was more efficient than the existing heating system (static heaters and hot air heating), ensuring heritage conservation and high thermal comfort to the churchgoers.