Water Heating Equipment Research Articles

Looking beyond energy efficiency targets: Life cycle sustainability of mechanical and water heating equipment in Canadian homes

The building sector's impacts on climate are widely acknowledged, leading to policies and standards promoting energy-efficient buildings. In order to achieve sustainability in a holistic sense, the environmental, social, and economic impacts of equipment used in buildings need to be evaluated. In this regard, a novel decision support framework is introduced to evaluate the heating and cooling equipment in single-family detached homes. Energy simulation, life cycle environmental, social, and economic analyses, and a multi-criteria decision-making method are used to identify the most sustainable set of equipment. This framework is demonstrated through its application on mechanical and water heating equipment in three existing residential buildings of varying energy efficiencies (low, medium, and high, the latter being net-zero home) over a 50-year study period.The results indicate that the carbon footprint of a natural gas furnace is six times higher than that of other equipment. In contrast, the drain water heat recovery unit showed the lowest impacts attributed to lower material and energy usage. For most equipment, the product stage accounted for more than 50% of the total impacts. When grouped, the equipment in the low-efficiency home showed the highest environmental impacts, while the equipment in the medium-efficiency home had higher social and economic impacts. Overall, the equipment set in a net-zero home is the best choice under equal, pro-social, and pro-economic scenarios and only lags behind the equipment set in a medium-efficiency home for pro-environmental scenario. The work will help improve sustainable building policies beyond immediate energy and operational cost savings.

Influence of scale deposits on the temperature conditions in the channels of plate-type heat exchangers

Introduction. At the present stage of development of the heat supply system, the transfer from shell-and-tube constructions to the plate version of heat exchange apparatus is observed. Their main advantages are compactness and efficiency.The main operational problem is the fouling of the inter-plate channels as a result of which the thermal efficiency decreases and operational costs increase. The aim of the work is to establish the dependence of fouling and individual hydraulic conditions in each channel on the temperature regime of a plate-type heat exchanger. Since this issue in the theory of heat exchange apparatuses is not well studied in and has significant assumptions, the diagnosis of fouling of channels is incorrect.
 Materials and methods. The theory of resistance characteristics of hydraulic systems is used to determine the hydrodynamic mode of plate-type heat exchange apparatus. The temperatures of heating and heated heat carriers at the outlet of each heat exchange channel are determined on the basis of the mass conservation law. This method made it possible to use the results of hydrodynamic calculation of resistance characteristics to calculate the temperature conditions of a plate heat exchange apparatus along the length of the plate pack, including the effect of scale deposits. The validity of the proposed methods was determined by comparing the Pearson’s and Student’s criteria with the results of computer modelling.
 Results. The dependence between final temperatures of the coolant at outlet of channels depending on the flow distribution of the coolant, taking into account channel impurity was found. The application of the theory of resistance characteristics to calculate the thermal-hydrodynamic mode of the plate heat exchanger and the proposed calculation of the thermal regime, including taking into account the factor of fouling, will improve the accuracy of pollution diagnosis and reduce operating losses.
 Conclusions. The conducted research confirms the influence of fouling of heat-exchange apparatuses and individual hydraulic conditions of inter-plate channels on the temperature regime. Results of research represent scientific and practical interest at studying and development of the intensified surfaces of heat exchange with the purpose of increase of power indicators of heat-exchange apparatuses, and also in the field of diagnostics of mode parameters of water-heating equipment in the period of its operation.

Study of Modified Absorber Plate with Aluminium Foam of Solar Water Heating System

Solar water heating system (SWHS) is water heating equipment that utilizes solar energy for domestic and industrial needs. An absorber plate is the main part of the SWHS that functions to absorb solar energy. Porous materials are efficient in increasing heat transfer, energy efficiency, energy storage, and reducing reflectance losses. Efforts have been made to add aluminium foam as a porous material on the lower and upper surfaces of the absorber plate. Porous materials function absorb heat and store radiant heat energy before being transferred to the fluid. Experimental tests were carried out by testing three models of absorber plates on a solar thermal energy unit with similar conditions. The first model is a standard flat plate (SFP) without aluminium foam. The second model combines standard flat plate and aluminium foam (SFP-TAF), placed on top of the SFP. The third model combines standard flat plate and aluminium foam (SFP-BAF), placed under the SFP. The results showed that the SFP-BAF model has a higher thermal efficiency than the other models. The SFP-BAF model has an efficiency increase of 2.71 % at a flow rate of 10 L/h and 5.39 % flow rate of 12 L/h compared with the standard model (SFP). The position of the aluminium foam at the bottom surface is substantial enough to help absorb and store radiant heat for transfer to circulating water.

Household Energy Consumption Patterns and Carbon Emissions for the Megacities—Evidence from Guangzhou, China

Over the last 20 years, energy consumption in the residential sector in China has grown rapidly, and the growth is faster than that of any other energy form. To assess the limitations of the spatial characteristics of household energy consumption in urban areas, this paper selected Guangzhou as the research area. Specifically, the old town, core area, central area and peri-urban areas, which best reflect the evolutionary characteristics and spatial differentiation of households, were assessed. Based on the surveyed database of community-scale household energy consumption (N = 1097), the spatial heterogeneity of household energy consumption and carbon emissions at the community scale were assessed through exploratory spatial data analysis and the standard deviation ellipse method. The results report that (1) the main sources of energy consumption in Guangzhou households were water heating equipment, kitchen equipment and refrigeration equipment, which were related to the climatic conditions and cultural traditions of the city. (2) There was significant spatial heterogeneity in the carbon emissions from household domestic energy use in Guangzhou. (3) The economic level, the effects of the Lingnan culture and the characteristics of residents are the main drivers influencing the spatial characteristics of household energy consumption and carbon emissions in Guangzhou. We propose that policy development should actively promote energy-efficient equipment, such as water heating and cooling equipment, in urban households and take full account of the basic household energy needs of residents in old urban and suburban areas while promoting the development of low-carbon buildings.

The usage of water conditioning sludge from heat power industry enterprises in wall ceramics production

The paper considers the ecological problems of water conditioning systems at heat power industry facilities. It is noted that the stable operation of water-heating equipment is provided with the quality of feed water. Various water-soluble salts, which can incrust the inner walls of boilers or pipelines, are removed from the natural water. For desalination of natural water the physical-chemical methods are mostly used. The by-product of desalination or chemical water-conditioning systems is the sludge waste. This work presents the results of using chemical water conditioning sludge from JSC Verofarm in the raw charge for wall ceramics production. The sludge is a finely-divided powder, the mineral composition of which is presented with calcium and magnesium carbonates, brucite and iron compounds, which make the sludge pink. It has been determined that the baking of sludge-containing ceramic samples at temperature 1000°C results in dissociation of calcium and magnesium carbonates with the formation of gaseous products H2O and CO2, which make the structure of ceramic materials porous. The presence of iron compounds in the raw charge promotes the formation of low-temperature silicate melt, which intensifies the baking process of ceramic samples. The optimal sludge content in the charge that doesn’t reduce the strength characteristics of wall ceramics is 10%. Such sludge content forms the liquid phase on the surface of the raw mix’s particles, which solidifies the forming pores. The increase of sludge content up to 20% intensifies gas generation; the amount of the formed liquid phase is not sufficient, which increases porosity and reduces the density and strength of ceramic materials. At that, the engobe layer is formed on the surface of the obtained wall ceramics samples. The wall ceramics products, obtained with the use of chemical water conditioning sludge, can be used as structural heat-insulation materials in making building envelopes or interior partitions.

State-wide comparative analysis of the cost saving potential of Vuilleumier heat pumps in residential houses

The Vuilleumier cycle-based heat pump is a promising technology that can break the capped natural gas end-use efficiency of 100%. This study compares the natural gas driven Vuilleumier cycle-based heat pumps with the common electricity driven vapor compression cycle-based heat pumps in terms of the exergy efficiency and the operating cost. Cycle analysis is performed to show the relations between the existing devices, their ideal counterparts, and the absolute thermodynamic limit of an ideal Carnot heat pump. With regards to operating cost, these two types of heat pumps are benchmarked in building energy simulations against the commonly used system of space heating, cooling and water heating equipment, to show the annual operating cost saving or deficit across the United States. In addition, three locations are selected to show the detailed annual operating cost and the energy demand profile. The results suggest that the Vuilleumier cycle-based heat pumps can be highly cost effective across the United States with an annual operating cost savings as high as $1230 in Vermont or an annual percentage cost savings as high as 52% in California.

Inhibitor Protection of Steel Against Corrosion and Scaling Under the Influence of Ultrasound

We study the combined action of reagents and ultrasound on corrosion and scaling under the conditions of operation of water-heating equipment at a temperature of 95 ?? 2???? and under atmospheric pressure. The efficiency of a known agent (oxyethylidene diphosphonic acid) and a ???green??? inhibitor based on the extract of rapeseed oil meal is found in high-hardness water both under the conditions of their individual action and in combination with ultrasonic irradiation of the medium in the subcavitation mode. The scaling (according to the mass increments) and corrosion (by the method of polarization resistance) rate are determined on the same samples. The functional time dependences of the specific scaling and corrosion rates are obtained under the conditions of reagent, ultrasonic, and combined treatment of water. It is shown that ultrasound exerts a negative influence on the antiscale properties of the investigated reagents by decreasing the efficiency of action of the antiscalant. A protective anticorrosion film is formed on the steel surface with time, as follows from the behavior of the corrosion rate, which sharply decreases in the initial period of the tests and then stabilizes on a level of 0.02 mm/yr. It is demonstrated that the complex influence of antiscalants and ultrasound in certain modes of treatment of the medium makes it possible to optimize the formation and preservation of a phase microlayer with antirust properties, which exerts almost no influence on the heat exchange between the metal surface and the heat carrier.

Characterizing energy-related occupant behavior in residential buildings: Evidence from a survey in Beijing, China

Despite progress in energy efficiency technologies and energy intensity reduction, the buildings sector's final energy consumption and associated CO2 emissions both continue to grow, pointing to the necessity of understanding real occupant behavior. This study, therefore, explores occupants' energy-related behavior in residential buildings with empirical data from a large-scale survey in Beijing, China, aiming to present an in-depth and comprehensive picture of occupant behavior. We obtained a total of 1003 valid responses to an online questionnaire concentrating on occupant behaviors with respect to space heating and cooling, water heating, cooking, lighting, appliances and other equipment. Our results show that, typically, purchase behavior is overall energy-efficient, as most appliances purchased are energy efficient. For both purchase and usage behaviors, air conditioning (AC), which is used for both space heating and cooling, plays a critical role as residents usually have less energy efficient AC in their homes and use it more often and for a longer period of time than other devices. Their habitual reactions are consistent across all habitual categories, but show no significant correlation with their purchase behavior. There is no single, straightforward and coherent pattern that can be explained by any single socio-demographic factor. These findings offer a behavioral insight into efforts to improve residential energy efficiency at the city scale. For instance, more policy attention should be directed to occupants’ purchase and usage behavior of ACs, such as by promoting the energy rating program in a more effective way. Moreover, given the lack of apparent linkage between purchase and habitual behaviors, a comprehensive policy framework incorporating different measures for different types of behavior is necessary. The complexity underlying behavioral choices also suggests the necessity of better understanding the behavioral patterns and their determining factors, as well as avoiding any simplistic assumption in policy making that aims to take behavioral factors into account.

The Design of A Digital Timing Automatic Feeder With Adjustable Temperature and Humidity

Abstract An automatic feeder for poultry farm with digital display, adjustable temperature and humidity and timing function. It is mainly composed of feeding mechanism, feeding mechanism, travel mechanism, temperature humidity and electrical control box with digital display, can display 24 hours, and with time setting function, in the case of a single intervention to perform automatic feeding work, reduces the labor cost, not only can reduce the time of staff contact with poultry, reduce the spread of disease. With a temperature humidity sensor at the same time, the real-time monitoring and display of breeding field numerical, temperature and humidity can be set to allow upper and lower limits of temperature and humidity fluctuations, and according to the set point control spraying water pump, fan, or heating equipment synchronization work, simplifies the operation of separation equipment, precise control of the feeding environment of temperature and humidity value, achieve the goal of the poultry feeding scientifically.

Detailed energy model of the National Institute of Standards and Technology Net-Zero Energy Residential Test Facility: Development, modification, and validation

The National Institute of Standards and Technology Net-Zero Energy Residential Test Facility is a highly instrumented, highly configurable, single-family, net-zero energy house occupied by a virtual family of four. A detailed transient model of the Net-Zero Energy Residential Test Facility and the accompanying mechanical equipment was created using information available before construction; the model incorporated building geometric details and construction material properties, as well as manufacturers’ specifications for HVAC, water heating, solar photovoltaic and other equipment. This model represents the typical design paradigm, where actual building performance and detailed equipment operation are not known. This original model underpredicted the measured annual energy consumption by 13.8%. The measured data were used to understand and correct the sources of error at the component level; modifications to the heating, ventilation, and air-conditioning system, interior thermal capacitance, and domestic hot water system improved the energy consumption prediction to within 1.6% of measured data. The differences between the original and modified models are useful for understanding the sources, magnitudes, and possible corrections to errors in energy models for high-efficiency residences. The modified model will be used in future studies of alternative energy system configurations and control strategies, contributing to cost-effective and optimum design of net-zero energy houses in America.

Scenarios to decarbonize residential water heating in California

This paper presents the first detailed long-term stock turnover model to investigate scenarios to decarbonize the residential water heating sector in California, which is currently dominated by natural gas. We model a mix of water heating (WH) technologies including conventional and on-demand (tank-less) natural gas heating, electric resistance, existing electric heat pumps, advanced heat pumps with low global warming refrigerants and solar thermal water heaters. Technically feasible policy scenarios are developed by considering combinations of WH technologies with efficiency gains within each technology, lowering global warming potential of refrigerants and decreasing grid carbon intensity. We then evaluate energy demand, emissions and equipment replacement costs of the pathways. We develop multiple scenarios by which the annual greenhouse gas emissions from residential water heaters in California can be reduced by over 80% from 1990 levels resulting in an annual savings of over 10 Million Metric Tons by 2050. The overall cost of transition will depend on future cost reductions in heat pump and solar thermal water heating equipment, energy costs, and hot water consumption.

Techno-economic assessment of photovoltaic (PV) and building integrated photovoltaic/thermal (BIPV/T) system retrofits in the Canadian housing stock

Techno-economic impact of retrofitting houses in the Canadian housing stock with PV and BIPV/T systems is evaluated using the Canadian Hybrid End-use Energy and Emission Model. Houses with south, south-east and south-west facing roofs are considered eligible for the retrofit since solar irradiation is maximum on south facing surfaces in the northern hemisphere. The PV system is used to produce electricity and supply the electrical demand of the house, with the excess electricity sold to the grid in a net-metering arrangement. The BIPV/T system produces electricity as well as thermal energy to supply the electrical as well as the thermal demands for space and domestic hot water heating. The PV system consists of PV panels installed on the available roof surface while the BIPV/T system adds a heat pump, thermal storage tank, auxiliary heater, domestic hot water heating equipment and hydronic heat delivery system, and replaces the existing heating system in eligible houses. The study predicts the energy savings, GHG emission reductions and tolerable capital costs for regions across Canada. Results indicate that the PV system retrofit yields 3% energy savings and 5% GHG emission reduction, while the BIPV/T system yields 18% energy savings and 17% GHG emission reduction in the Canadian housing stock. While the annual electricity use slightly increases, the fossil fuel use of the eligible houses substantially decreases due to BIPV/T system retrofit.

RESEARCH OPERATIONAL SAFETY OF PROCESS EQUIPMENT AT LOSS OF CALCIUM CARBONATE

The article describes the process of operation of water heating equipment, associated with water, which requires compliance with certain water regime. It is focused on the consequences and their elimination when using water heating equipment, and safe operation. The results of physical and chemical analyses of artesian water have been ordered.

Sensitivity Analysis of Common Input Parameters in Tools for Modeling Energy in Homes

Energy models of buildings can be developed and used for analysis of energy consumption. A model offers the opportunity to simulate a building under specific conditions for analysis of energy efficiency measures or optimum design. Due to the great amount of information needed to develop an energy model of a building, the number of inputs can be reduced by making variable the most relevant input parameters and making the others to take common or standard values. In this study, an analysis of input parameters required by computational tools to estimate energy consumption in homes was done in two stages. In the first stage, common input parameters were identified for three software and three webtools based on the criteria that the input parameter should be common for at least two software and at least one webtool. In the second stage, a sensitivity analysis was performed on the inputs identified in the first stage. The software BEopt, developed by the National Renewable Energy Laboratory, was used as the source of typical input parameters to be compared, and to perform the simulations for the sensitivity analysis. The base or reference model to perform simulations for the sensitivity analysis corresponds to a model developed with information from a research house located on the campus of the University of Texas at Tyler and default inputs for the BEopt B-10 reference benchmark. Results show that besides the location, and consequently the weather, common parameters are building orientation, air leakage, space conditioning settings, space conditioning schedule, water heating equipment, and terrain. Among these parameters, the sensitivity analysis identified the largest variations in energy consumption for variations on space conditioning schedule (heating and cooling setpoints), followed by the type of water heating equipment. KEYWORDS: Residential Buildings; Energy Consumption; Energy Analysis; Input Parameters; Building Simulation; Source Energy

Improving the logistics of a constant order-cycle kanban system

Kanban systems are simple, effective means of improving production that are widely applied in practice. Based on the logistic process involved, kanban systems can be divided into constant order-quantity and constant order-cycle systems. The former has received much research attention, but the latter, also known as a milk run, has been relatively neglected. Further, most prior work has been based on deterministic data, which is an assumption often violated in practice. We present the case of a manufacturer of domestic water heating equipment where a constant order-cycle kanban implementation initially failed. A structured Define–Measure–Analyse–Improve–Control approach is adopted to improve the process. It was revealed that the failure was due to high variability in the logistic processes involved. Decreasing this variability resulted in a reduction of tardy replenishment routes from 50 to 3%; a reduction in the route time coefficient of variation from 40 to 16%; and a reduction in the mean route time from 31 to 25 min. These improvements allowed one of three existing routes to be eliminated without any negative impact on replenishment. This led to financial savings through the elimination of two operators. The logistic process appears to have a significant impact on kanban performance. Consequently, kanban implementations should not only focus on the kanban system itself but also on the other processes involved. Future research should therefore explore how resources can best be allocated between the different aspects required for a successful kanban implementation.

Architecture Design of Building Integrated Solar Collector

Solar thermal collector converts solar radiation energy into useful thermal energy and transfers to a transport fluid flowing through the system. The collected energy can be used either direct to space or water heating equipment, or to a thermal storage for later use. Along with fast development, not only domestic hot water supply is needed, but also space heating and cooling are required. Also, limited roof space is another key barrier that should be considered. Furthermore, most of the building integration with solar collectors are mounted on the roof top by flat or tilt angle at present. It is considered to be a failure of low level architectural quality because the collector is used only for application and seems as an independent technical element of the building. With the consideration of the above, novel type of solar collector has been proposed to realize the utilization and offset the barriers. This novel solar collectors is especially suitable to supply domestic hot water, and combines with ASHP for multi-function, space heating and cooling as well as domestic hot water supply. Additionally, it is well integrated with high-rise residential buildings, which is good for aesthetic.

Feasibility Study of Using Domestic Solar Hot Water Systems as Alternative to Reduce the Electricity Peak Demand in Brazil

Brazil is one of the few countries where the water heating for bath is performed by using electric showerheads. The widespread use of these devices is the mainly responsible for the high peak on the electricity demand of the residential sector, observed between 18:00 and 21:00hours. As a consequence of that, costs and service quality are undermined, affecting consumers and the electricity sector in general. In attempt to deal with this issue, solar hot water systems have been proposed as an option to reduce the electricity consumption of the showerheads. However, despite of the high incidence of solar radiation on the Brazilian territory indicates a significant economy, currently there is no technical assessment quantifying the economic benefits on the region. The present study estimates the economic impacts resulting by the deployment of solar hot water systems in Brazilian households. Hence, the feasibility study allows assessing the potential of solar water heating as alternative to reduce the peak on the electricity demand in Brazil. In order to perform the proposed analysis, long-term performance simulations were performed on an hourly basis using the TRNSYS software as computational tool and typical meteorological year (TMY) files as input data. The TRNSYS component (Type 45) relating the solar water heating equipment had been experimentally validated, whereas the weather data was obtained from the SWERA database. Also, a time dependent profile of the heating demand is considered, according the measurements collected in previous studies. The thermal performance is evaluated in terms of solar fraction. On the other hand, the economic impacts are quantified in terms of three criteria for economic feasibility, such as payback period, internal rate of return and life cycle savings. In order to explore the benefits arising from different policies, four tariff scenarios are considered. The economic evaluation is positive over all scenarios analyzed, showing savings for both, the consumers and the electricity sector. The results of this analysis can be used as support tool for target setting the adoption or spread the use solar water heaters, or even to create policies for its diffusion.

Policies to Encourage Home Energy Efficiency Improvements: Comparing Loans, Subsidies, and Standards

Residential buildings are responsible for approximately 20 percent of U.S. energy consumption, and single-family homes alone account for about 16 percent. Older homes are less energy efficient than newer ones, and although many experts have identified upgrades and improvements that can yield significant energy savings at relatively low, or even negative, cost, it has proved difficult to spur most homeowners to make these investments. In this study, I analyze the energy and carbon dioxide (CO2) impacts from three policies aimed at improving home energy efficiency: a subsidy for the purchase of efficient space heating, cooling, and water heating equipment; a loan for the same purchases; and efficiency standards for such equipment. I use a version of the U.S. Energy Information Administration’s National Energy Modeling System, NEMS-RFF, to compute the energy and CO2 effects and standard formulas in economics to calculate the welfare costs of the policies. I find that the loan is quite cost-effective but provides only a very small reduction in emissions and energy use. The subsidy and the standard are both more costly but generate emissions reductions seven times larger than the loan. The subsidy promotes consumer adoption of very high-efficiency equipment, whereas the standard leads to purchases of equipment that just reach the standard. The discount rate used to discount energy savings from the policies has a large effect on the welfare cost estimates.

Solar Hot System and Design of Buildings

Domestic solar hot water system, the use of the status quo and existing problems, by analyzing the solar water heating equipment and building integrated and building integrated design.

Nonlinear inversion-based control of a distributed parameter heating system

Abstract In this work the control of a pilot-scale water heating equipment was studied. The water flows through a tube, in which it was heated by electric power. The outlet temperature was controlled by the flow rate, compensating heat duty and inlet temperature disturbances. This device shows resemblance to solar collectors and heat exchangers, thus making it a useful tool to carry out controller experiments for similar objects. The method of constrained inversion was applied. This control strategy is based on the first principle model of the process and feed-forward control. Two different approaches were compared in handling the distributed parameter system. To eliminate steady-state error, a feedback compensation was needed, which was implemented in an IMC structure. Experimental results showed that both controllers were superior to the conventional PI controller. Compensation of dead time, nonlinearity and measured disturbances are the key factors in the success of the model-based controller.