Residual Heat Energy Research Articles

Multivariate regression studies for the investigation of the COD, BOD, and TOC concentrations in the water of the Styr River within the zone of influence of the power plant discharge

Abstract The discharge of cooling water into surface waters containing residual heat energy is a pressing issue in the environmental impact of nuclear power. Cooling water flow can cause negative changes in the water and ecological processes of natural waters, in particular an imbalance of organic matter, in combination with a complex of natural factors. The purpose of the article was to perform a statistical analysis of the dynamics of organic matter content in the water of the Styr River in the Rivne Nuclear Power Plant (Rivne NPP) impact zone to assess the manifestation of the environmental impact of the discharge of cooling water with residual heat. The monitoring data series consisted of the results of monthly monitoring of the rate of chemical oxygen demand, the rate of biochemical oxygen demand in 5 days, and total organic carbon in the Styr River sections before and after the discharge of Rivne NPP cooling water in 2018–2022.

CO2/acetone mixture desorption process in a plate heat exchanger for compression/resorption heat pumps

Industrial processes represent one of the activities that consume the most energy, which is related to the use of fossil fuels and growing environmental problems. In this way, the recovery of residual heat energy has been presented as an efficient solution to take advantage of low-quality residual heat, where the compressor-resorption heat pump technology has proven to reach high temperature levels with a considerable Coefficient of Performance. The importance of this work lies in the validation of the ecofriendly CO2/Acetone mixture as a useful working fluid for a compressor-resorption heat pump, initiating the experimental study in the desorption process as a novel application. Even more, the cycle of the bomb has been simulated on previous research regarding a literature comparative and the present work validates it by experimental means. The process of desorption of the CO2/acetone mixture was studied in a heat exchanger of plates with operating conditions for conducts formed by 4 plates/3 channels, for compression/resorption heat pumps. Result ranges have been obtained for solution heat transfer coefficient between 0.10 and 0.50 kW × m−2 × K−1, average vapor flow rate between 0.02 and 0.16, heat flow rate between 1.50 and 5.20 kW × m−2 × K−1 and desorption mass flow rate between 2 and 5 kg × m−2 s−1 × 10−3 in the central channel of the plate heat exchanger. Finally, an empirical correlation is proposed to extend the results of the heat transfer coefficient of the CO2/acetone solution in applications outside the experimentally determined range, from the comparison between experimental data and determined by correlation of enthalpy of the solution, an average minimum, mean and maximum deviation of 0.2, 13.5 and 22.3 %, respectively, was determined. In this way, the results shows that the most influential variables are the test pressure and heating water temperature at the inlet of the desorber, where, with a concentration of CO2 (XCO2) between 22 and 25 %, the heat transfer coefficients obtained have an order of 0.50 kW × m−2 × K−1. On the other hand, viscosity favours heat transfer, thermal conductivity is a determining factor for the desorption process. This contributes to lower heat transfer coefficient and heat flow in the heat exchanger for the CO2/acetone mixture compared to the other mixtures.

STUDY OF EXHAUST GAS RESIDUAL HEAT CONVERSION HRSG PLTGU KERAMASAN TO ELECTRICAL ENERGY WITH GENERATOR THERMOELECTRIC TECHNOLOGY

The Heat Recovery Steam Generator (HRSG) is a combination of a Gas Power Plant (PLTG) and a Steam Power Plant (PLTU), this plant utilizes exhaust gas from the PLTG to produce steam as the working fluid in the PLTU. The residual heat from the heating process at the HRSG is channeled into the chimney, and the remaining heat from the exhaust gas can be converted into electrical energy with the Thermoelectric Generator (TEG) module. This research was carried out by installing the TEG module in series on the surface of the HRSG chimney wall, using laboratory scale measurements. The heat source uses a heater with a total power of 2,000 W. The research results show that the TEG module can convert the residual heat energy of the exhaust gas from the HRSG chimney into electrical energy. Four TEG modules mounted on the chimney surface can generate a voltage of 0.83 V and a maximum power of 2.79 mW. These results indicate that the TEG module is an opportunity to convert heat energy into electrical energy for further development.

Predictive investigation of the combined heat storage system using at NPPs with VVER

The increase in the share of nuclear power plants in the energy systems leads to the need for their participation in covering the irregularities in the electrical load schedules. NPPs unloading is economically unsustainable. Combining NPPs with storage systems can be a solution to this problem, as it will allow the reactors to operate at a constant capacity utilization factor, while excess energy will be stored during load dip hours and converted into electrical energy during peak load hours. The authors have developed a thermal storage system based on the combination of a phase change accumulator with hot and cold water tanks. The system also contains a steam turbine to generate electricity during peak hours using stored energy. Earlier the authors proved that a low-power turbine can be used to supply power to the NPP auxiliary needs with a blackout using only residual heat energy. In this paper, a methodology for determining the necessary operating parameters of the storage system for using under the required conditions is presented. The investigation of economic efficiency was carried out on the example of a range of electricity tariffs for the world’s energy systems. Accumulated net present value ranged from $0 to $85 million.

Study of temperature impact of discharges and balance of biogenic elements in the water of the Styr river in the impact zone of the Rivne NPP

Regardless of the type of cooling cycle, all nuclear power plants (NPPs) have a cooling water discharge with residual heat energy. Significant volumes of water are circulated in the cooling system of an NPP, which is withdrawn and discharged into a natural water body, thus transferring heat from the power plant to the water body. Changes in the content and balance of biogenic substances in surface waters under the influence of water discharges from an NPP can be considered as important indicators of water and environmental reactions to heat emissions from an NPP. The study aims to determine the dynamics of changes in the content of biogenic elements for the coexisting forms of nitrogen (N), phosphorus (P), and carbon (C) with the establishment of variability factors and correlations between their forms in the water of the Styr River, which is in the zone of water discharges influence from the Rivne Nuclear Power Plant (Rivne NPP). According to the results of the study, it was determined that the content of P (orthophosphate ions РО4 3-), C (biochemical oxygen demand for 5 days BOD5 and chemical oxygen demand COD) and N (ammonium nitrogen N-NH3 , nitrate ions NO3-) in the water of the Styr River in the zone of influence of water discharges from the Rivne NPP has seasonal dynamics. The correlation of the balance content of nutrients in the water of the Styr River before water intake and after discharge by the Rivne NPP was estimated. Regression statistical dependencies were established, which allow predicting the content of nutrient forms depending on the temperature by environmental and technical factors of temperature influence. In general, the research results indicate that there is no negative impact of the Rivne NPP water discharges on the balance of nutrients, and therefore no manifestation of the Styr River water-ecological reactions to the Rivne NPP heat release.

Conversion of Waste Heat from Automobiles into Electrical Energy using Thermoelectric Generators

In our current environment, the expanding interest for energy, with fast consumption of our assets, we should be centered around utilizing economical and sustainable power that produces eco-accommodating energy and lower carbon emanations. So, it is significant that the accessible energy ought to be monitored and used productively. In an internal combustion engine utilized in cars have a limit of 25%-33% effectiveness and the residual heat energy got by the burning cycle goes through the fumes and afterward into the environment. This prompts the expansion in discharge of unsafe gases which increments an unnatural weather change and other natural issues. This caused to grow the consideration on improving the productivity of internal combustion engines. For the utilization of waste heat from a vehicle exhaust our primary goal is Thermoelectric Generators (TEG). It is an exceptionally doped semiconductor strong state gadget, which changes over the heat on the fumes surface straightforwardly into electrical energy and this would permit a huge increment of the general ignition motor execution. The thermoelectric materials and the position of installation plays an important role in increasing the efficiency.

New Solution To Apply Constructed Wetland Technology In Cold Climate

Due to the influence of low temperature in winter, the removal effect of pollutants in constructed wetlands in winter is greatly reduced. In order to improve the removal effect of wetland on pollutants such as nitrogen and phosphorus, this paper proposes a new insulation method that uses the residual heat of bathroom bath waste water to supply heat to the constructed wetland. In the proposed new wetland system, the average removal rates of TN, TP and NH4 +-N in wetlands reached 61.09%, 85.03% and 33.85%, respectively. The application of residual heat energy to the construction of constructed wetland can realize the recovery and utilization of energy, which is conducive to the promotion and application of constructed wetland in the cold regions of the north. A post-publication change was made to this article on 29 May 2020 to correct an author name on the webpage.

Experimental evaluation of a long still with galvanised iron sheet as condensing cover at different basin water flow rate: study of heat and mass transfer

Experimental and theoretical evaluation of a long still for the utilisation of residual heat energy from hot wastewater discharge of thermal power generation-based organisations has been investigated and reported in this paper. The experiment has been carried out to find the variation in productivity with respect to different feed rates viz 100, 150, 200, 250 and 300 LPH at 10 different points. It has been observed that the distiller unit at a feed rate of 250 LPH gives maximum distilled output as compared to the feed rates of 100, 150, 200, and 300 LPH. At 250LPH flow rate, a distill yield of 0.0868 kg/h is recorded which is 34.99, 17.14, 4.52, and 0.01% higher as compared to the 100, 150, 200 and 300 LPH flow rate feed hot waste water, respectively. It has been observed that the long still gives maximum and minimum yield at entrance and exit, respectively.

Thermal Response of Skin Underneath a Thermal Protective Garment During Post-fire Exposure

Once away from a heat source, the residual heat energy absorbed by thermal protective garments can continue to transfer and can injure human skin. Such a post-fire exposure period should not be neglected when investigating the thermal protective ability of thermal protective garments. In our paper, a heat transfer model of a microsystem consisting of a thermal protective garment, an air gap and multilayer human skin is established, and numerically solved via the Finite Element Method. Temperature distributions of the microsystem during fire exposure and post-fire exposure are extracted from the model, and the thermal behavior of skin underneath the thermal protective garment is elucidated. Two parameters [retardation time (Δt) and temperature maximum (Tmax)] are proposed and employed to assess the thermal response of human skin during the post-fire exposure period. Furthermore, the effect of several factors (heat source intensity, thickness and thermophysical properties of the garment, and air gap thickness) on the two parameters and the thermal behavior of human skin are investigated and compared. This might be a significant reminder of self-protection for firefighters on duty, and informative or thermal protective garment design.

Investigation of the possibility of using residual heat reactor energy

The largest contribution to the probable frequency of core damage is blackout events. The main component of the heat capacity at each reactor within a few minutes following a blackout is the heat resulting from the braking of beta-particles and the transfer of gamma-ray energy by the fission fragments and their decay products, which is known as the residual heat. The power of the residual heat changes gradually over a long period of time and for a VVER-1000 reactor is about 15–20 MW of thermal power over 72 hours. Current cooldown systems increase the cost of the basic nuclear power plants (NPP) funds without changing the amount of electricity generated. Such systems remain on standby, accelerating the aging of the equipment and accordingly reducing its reliability. The probability of system failure increases with the duration of idle time. Furthermore, the reactor residual heat energy is not used. A proposed system for cooling nuclear power plants involves the use of residual thermal power to supply the station’s own needs in emergency situations accompanied by a complete blackout. The thermal power of residual heat can be converted to electrical energy through an additional low power steam turbine. In normal mode, the additional steam turbine generates electricity, which makes it possible to ensure spare NPP and a return on the investment in the reservation system. In this work, experimental data obtained from a Balakovo NPP was analyzed to determine the admissibility of cooldown of the reactors through the 2nd circuit over a long time period, while maintaining high-level parameters for the steam generated by the steam generators.

Accumulation of residual energy of an experimental stove after burning

Engineers, architects and designers increasingly rely on mathematical constructs incorporated into civil engineering programs to explain physical and mechanical phenomena. A low thermal diffusivity represents a material’s ability to slow down the rate of heat transfer due to heat absorption and storage, so that high thermal masses are desirable. The thermal inertia of the earth structures in general is an under-researched topic, especially regarding their unique ability to delay and attenuate temperature responses. The paper uses a high temperature difference example, in the form of an experimental stove, to highlight the benefits of a thermal mass. Countries such as Austria, the Czech Republic and Slovakia are known for their ornate historical masonry stoves that grace many stately houses, castles and palaces. They were stoked once or twice daily and radiated heat constantly during the winter months. This guild developed and thrived until the advent of modern HVAC systems in the 20th century. The paper sets out to monitor the temperature difference produced by stoking and firing a simplified experimental stove and analyses the decrease in temperature until it approaches a fixed room temperature. Temperature and heat flux are then observed to determine the total residual heat energy after burning, and the results are discussed in the conclusion. Inspired by these sound principles, based on lessons from the vernacular building traditions that have been used for centuries, the output of this work could be used in future to design an appropriate amount of the thermal mass to maximize thermal efficiency in fireplaces and stoves and as a precedent for a synergetic combination of the thermal mass and renewable energy sources.DOI: http://dx.doi.org/10.5755/j01.ct.68.1.15006

Research on the Value Depth Development of Energy Conversion Function in Iron and Steel Process

In this paper, the theory of "three functions" in the Metallurgical Process Engineering is applied,on the basis of analyzing the process of energy transformation in iron and steel manufacturing process, the composition of energy cost and the potential of energy saving and efficiency in iron and steel enterprises were analyzed,and the functional characteristics and value advantage of energy conversion in iron and steel process are analyzed.This paper pointed out that energy flow of "vector" characteristics and quality of energy value is an important source under the low system efficiency. This paper considers that the value of energy conversion function in iron and steel process should be further developed, and the cross-border expansion within the scope of the process and other industries can not only optimize the process of iron and steel enterprises value at a higher level, but also an important means to realize the development of green transformation of the industry. At this stage, the system optimization method, the implementation of the top-level design, the formulation of energy system optimization solutions, mining the energy consumption limit of the process, and improvement the residual heat energy self generation ratio should be an important focus to enhance the system energy efficiency of the steel enterprise. To build a new platform of the "iron and coal chemical industry" for chemical synthesis of blast furnace gas, coke oven gas,converter gas utilization appreciation as the core, to realize the associated gas resources chemical substance conversion are the core value of iron and steel process huge potential.

Reuse of the Reflective Light and the Recycle Heat Energy in Concentrated Photovoltaic System

A complex solar unit with microcrystalline silicon solar cells placed around the centered GaAs triple junction solar cell has been proposed and carried out. With the same illumination area and intensity, the total resultant power shows that the excess microcrystalline silicon solar cells increase the total output power by 13.2% by absorbing the reflective light from the surface of optical collimators. Furthermore, reusing the residual heat energy generated from the above-mentioned mechanism helps to increase the output power by around 14.1%. This mechanism provides a simple method to enhance the utility rate of concentrated photovoltaic (CPV) system. Such concept can be further applied to the aerospace industry and the development of more efficient CPV solar energy applications.

Steel and sustainability: Scandinavian perspective

A description is given of practice at the steelplant of SSAB Tunnplåt AB in Luleå, Sweden, and of progress in the recycling of residuals and reducing environmental impact. An extensive study of greenhouse gases in steel production to slabs was carried out by SSAB during the years 2000–02. Current and new processes and possible alternatives were studied, as well as the effect of the product programme. Various emission alternatives were considered using a global calculation(SSAB plus combined heat and power (CHP) plant), and conclusions for long term and short term possibilities were discussed. Major efforts have been made recently to develop process integration technology. In Sweden, this has been realised within a national programme for the total processing industry (steel, pulp and paper, petrochemicals, food). There are synergies, as the optimisation problem itself is relatively similar, independent of industry sector. Similar efforts have been made in other Scandinavian countries, and a joint Scandinavian programme has been carried out. Discussions of ore versus scrap based metallurgy are often founded on the assumption that these routes are alternatives to each other. This is not the case; instead, ore based metallurgy is the first step in a series of subsequent life cycles, and both routes are necessary to carry out the 'cycle of cycles'. The philosophy of this is discussed. The Scandinavian climate makes the use of residual heat energy for district heating and cooling economically important, and a part of energy/sustainability considerations. Significant R&D efforts are being and have been made to increase recycling. Two programmes/centres of excellence in this field are described.

202 焼却施設におけるガスタービン複合発電の評価

After "the Action Program to Arrest Global Warming" was decides at Cabinet in 1990,utilization of residual heat energy from waste incinerators has been positively put into effect to reduce fossil fuel use. Above all the combined system of a steam turbine and a gas turbine has been drawn considerable attention, which was introduced to our city and keeping a good performances. The system features ; (1) Effective use of an emergency power generator for cost reduction, (2) DSS operation of the gas turbine, (3) Automatic combustion rate tuning system aimed to maximize the income of generated electricity. The next step is planned to sell the residual electricity as a "green purchase item" at auction.

A Study of Eddy Fluxes Over a Forest

Eddy correlation instruments mounted above a plantation of Pinus radiato near Mt. Gambier, South Australia, have been operated during two periods of intensive effort, in May and October, 1972. Measurements of the Reynolds stress and of wind speed gradients show that the zero plane for momentum is located at about d = 0.8h (where h is the height of the trees), and that the roughness length of the surface is about 30% of the difference (h—d).Sensible heat fluxes and temperature gradients give a displacement length not significantly different from that applicable in the momentum case, but the roughness length for sensible heat transfer is smaller than that for momentum, by about a factor of 3.Advective effects are found to be important, particularly when the fetch across the canopy is less than about 0.8 km (corresponding in our case to an effective fetch/height ratio of between 100 and 200). Long-fetch cases allow an evaluation of the heat storage (S) in the canopy and in the air below the height of eddy flux measurement. The rate of heat storage is found to be about 60 ± 20 W m−2 per °C h−1 of canopy temperature change (for a densely packed forest with trees about 13 m high), which is compatible with measurements of the biomass and assumed specific heats. The residual heat energy at about 6 m above the effective zero plane, unaccounted for by the various measured fluxes, is found to be related to the difference in net radiation over grassland and forest.During daytime, the forest is found to lose heat by turbulence in much the same manner as pasture, with fluxes of similar magnitude (although possibly differing to the extent of differences in ground flux, albedo and emissivity, for example) and giving similar Bowen ratios. At night, however, the evaporation from the forest tends to continue as heat is supplied by the cooling canopy. This is in direct contrast to the usual situation over pasture, where the heat storage is not of sufficient magnitude to result in this behavior.