Utilization Of Secondary Energy Resources Research Articles

Моdern heat and steam supply systems of industrial enterprises using deep utilization of the technological steam energy potential

Steam supply systems of industrial enterprises, as a type of heat supply system, are a large consumer of primary energy in national energy balances. In turn, due to the specificity of thermodynamic steam processes, steam supply systems of industrial enterprises in practice have significant unused potential of secondary energy resources (SEP). Modern steam supply systems should be built exclusively when evaluating their exergetic efficiency, which will make it possible to evaluate the effectiveness of such systems grossly in all elements of the life cycle of the project: energy, economic, ecological and even social. The article shows modernized thermal schemes of steam supply systems, for which it is possible to achieve additional electrical power at the level of 135-250 kW/(kg/s) when devices with a relative internal efficiency of up to 60-70 % are operating. In combination with an increase in the percentage of condensate return and the utilization of secondary energy resources (SRP), the increase in energy efficiency of the system is 2-4 %, and the absolute value of exergetic efficiency is 16-22 %, taking into account the exergetic efficiency of the boiler unit. Low-potential "tail" consumers: the heating system, the hot water supply system - increase the exergy efficiency of the steam supply system of an industrial enterprise by 0.2-0.6 % in the case of joining on the steam side of secondary boiling. Any processes of generating electrical energy are associated with obtaining a significant amount of thermal energy, and must be accompanied by its utilization; enterprises that use steam as an energy carrier (the same applies to energy enterprises such as thermal power plants and nuclear power plants) for the deep utilization of hydroelectric power plants must have thermal energy consumers in their composition, which can act as communal household consumers (if they exist), as well as new technological consumers of thermal energy.

The “Smart Home” Heat Supply System Based on District Heating with the Utilization of Secondary Energy Resources Using a heat Pump

One of the most important aspects of a “smart home” is its heating system, which should provide comfortable living conditions for residents while also being energy-efficient. This article discusses an innovative approach to heating systems in “smart homes” based on centralized heating with the utilization of secondary energy resources using a heat pump. The proposed heating system combines the advantages of traditional centralized heating and the efficiency of heat pumps. The article presents a calculated scheme, for which a temperature chart was developed. A methodology for calculating heat loads for both the traditional heating scheme and combined heat and power (CHP) with heat pumps is also proposed, and the necessary calculations were carried out. For clarity of the obtained data, a graph depicting the total steam load required for heating as a function of ambient temperature is constructed, as well as a graph showing the steam load as a function of the duration of the ambient temperature. The analysis of the data revealed that the use of heat pumps in CHP schemes reduces electricity generation by eliminating its production in the steam flow in the condenser. This facilitates the coverage of the electricity consumption schedule during periods of low demand for the integrated energy system. Additionally, integrating a heat pump into the heating system of the centralized heating system helps reduce energy dissipation and greenhouse gas emissions into the atmosphere, making heating more sustainable and environmentally friendly. Moreover, the proposed heating system for a “smart home” demonstrates high technical and economic performance, ensuring the investment attractiveness of such a project.

Specific Features of Operation of Distributed Generation Facilities Based on Gas Reciprocating Units in Internal Power Systems of Industrial Entities

The creation of a decentralized low-carbon energy infrastructure is the main trend in the development of the electric power industry in many countries. Distributed generation facilities (DGs) based on gas reciprocating units (GRUs) are often built by industrial entities for the efficient utilization of secondary energy resources in order to minimize the environmental impact. Modern GRUs have some advantages, but they have design features that should be factored in when connecting them to the internal power systems of industrial entities. Incorrect consideration of possible operating conditions of GRU in their design can lead to their damage, excessive shutdowns, and disruptions in power supply to essential power consumers with significant damage and losses from undersupply of their products. Excessive shutdowns of GRUs are often caused by a non-selective choice of settings for relay protection devices or by load surges that exceed the allowable ones. With high availability factors, GRUs are disconnected five to eight times more often compared to large gas turbine and steam turbine power units. The large total power consumed by electric motors, as part of the load of an industrial entity, determines the nature and parameters of electromechanical transient processes during emergency disturbances. The presented analysis of issues facing real DG facilities relies on the acts of investigation into the causes of accidents. Calculations have shown that the action of the “Load Agreement Module” in the GRU excitation controller can provoke the occurrence of a voltage avalanche in the internal power system with a complete shutdown of the load. The paper presents recommendations on the choice of control algorithms and voltage settings for the GRU excitation controller. Technical solutions are given to prevent damage and excessive shutdowns of GRU in various operating conditions of the system, and to help ensure a reliable power supply to power consumers. The change in approaches to the design of DG facilities is substantiated in the light of their significant differences from other electric power facilities.

AUTONOMOUS POWER SUPPLY SYSTEM FOR SURFACE DISINFECTION BY INFRARED RADIATION IN PROTECTED GROUND

Reducing heat losses and utilization of secondary energy resources contribute to improving the energy efficiency of equipment, technologies and enterprises. The improvement of one of the processes in the technology of growing vegetables and berries, the use of thermal energy in the disinfection of surfaces in protected ground is the main idea of the developed autonomous power supply system of the installation. (Research purpose) The research purpose is developing a technological scheme of the power supply system of the installation for disinfection of surfaces with infrared radiation in protected ground. (Materials and methods) The article presents the scheme of an experimental installation for surface disinfection with infrared radiation, allowing to develop a technological scheme of the power supply system. The experimental setup is designed to study the distribution of the temperature field of infrared radiation on the surface (soil, substrate, concrete floor). (Results and discussion) During the operation of infrared radiators during disinfection of surfaces in protected ground running on liquefied gas, not all the thermal energy from gas combustion passes into infrared radiation; part of the thermal energy is lost to the environment due to convection and thermal conductivity. Losses can reach up to 50 percent. In order to reduce heat losses and reach the autonomy of the surface disinfection unit in protected ground, it was proposed to use thermal generators operating on the Seebeck - Peltier effect, the conversion of thermal energy into electrical energy for electricity generation. The Peltier elements are connected both sequentially and in parallel. The electricity received from the Peltier elements enters the battery, accumulates, and then is spent on the operation of the installation. (Conclusions) The technological scheme of power supply system of the surface disinfection plant being developed can be adapted and applied to other technological processes where there are heat losses to the environment.

The effectiveness of the scrubber method of cleaning exhaust gases in industry

Unfortunately, not all types of industry have a positive impact on the environment and people, for example, the processes of the chemical and textile industries can be accompanied by the release of toxic and harmful gases, dust and steam. And already, along with the exhaust gases, they are released into the atmosphere, while the negative impact on the overall environmental situation only doubles. That is why the importance of cleaning the emitted gases in the process of industrial activity cannot be underestimated. The most popular and most effective method of cleaning from dust emissions can be designated as the scrubber method of air purification, precisely at the moment when the air being eliminated has a relatively high temperature level. In addition, the use of the heat of condensation of water vapors contained in them is a particularly effective direction for increasing the depth of heat recovery of wet gas and steam generator gases leaving heat technology devices. This article is devoted to the study of the stages and models of the process of designing and constructing a device for wet cleaning of gases that are released into the atmosphere as a result of certain production activities. The study of the systems of utilization of secondary energy resources used at the present time was also carried out.

Анализ схем утилизации вторичных энергоресурсов судовых энергетических установок с газотурбинными двигателями

The article considers the most rational possible schemes of waste gas heat recovery in a marine power plant with gas turbine engines. The directions for improving the energy efficiency of gas turbine engines through the utilization of secondary energy resources are determined.

Influence of the degree of off-design of the traction nozzle of a jet reaction turbine on its efficiency

At the present stage of social development, the need for rational use of energy resources of the planet is particularly acute. Most countries have already faced the problem of the energy crisis. An appropriate way to solve this problem is the utilization of secondary energy resources. With the help of turbine generators, it is possible to reduce the pressure and utilize the potential energy of excess pressure of gas or vapours to produce electricity. Such units can be created based on a jet reaction turbine. The study aims to assess the impact of the degree of off-design of the traction nozzle on the efficiency of the jet reactive turbine. The analysis of the factors influencing the efficiency of the jet reaction turbine is carried out in the work. The obtained efficiency rate for the jet reactive turbine depending on the given dimensionless velocity of λout t at the inlet pressure of the inlet nozzle of 2, 4, 6 and 10 MPa in the design mode (at the degree of off-design of S = 1) and in the off-design modes of operation ( S> 1). Graphical dependencies of the jet reaction turbine efficiency rate on the given circular velocity of the impeller are constructed (U− = 0… 0.7). The research shows that with increasing pressure at the inlet to the inlet nozzle, the efficiency rate of the turbine increases, and the optimum of the efficiency rate is shifted towards the increase of the given circular velocity of the impeller, both in the design and off-design operating modes. It is found that the greatest value of the efficiency rate is acquired at the design mode of operation of the traction nozzle, i.e. at S = 1.

ТЕРМОДИНАМИЧЕСКИЕ ХАРАКТЕРИСТИКИ КОМБИНИРОВАННЫХ ЦИКЛОВ ВАКУУМНЫХ МИКРОГАЗОТУРБИННЫХ УСТАНОВОК ТЕПЛОЭЛЕКТРОСНАБЖЕНИЯ ЛОКАЛЬНЫХ ОБЪЕКТОВ

The subject of this article is the use of organic Rankine cycle (ORC) plants to improve the efficiency of vacuum cycles of micro-gas turbine engines (VMGTE). Combined installations VMGTE with ORC of a simple cycle and with heat regeneration have been investigated. The optimal parameters of the plants in the mode of the switching heat flow are found for various working fluids of the ORC. It has been established that the combination of VMGTE with ORC allows to increase the efficiency of plants by 4.2 ... 12.5%, while maintaining cogeneration capabilities. Due to the design features, the combined plant based on a simple cycle can be used for the utilization of secondary energy resources of any potential.

Визначення економічної ефективності схем термохімічної регенерації для теплових двигунів

On the example of gas-turbine plants, we have considered the principal and constructive schemes of thermochemical recuperation for the utilization of secondary energy resources, namely, the enthalpy of exhaust gases. We have developed methods of the calculation of thermodynamic and heat-transfer characteristics of these schemes. We have carried out wide numerical investigations of the technical-and-economical parameters of schemes of thermochemical recuperation and determined their dependences on temperature conditions. We have established that the pay-back period is usually equal to several months, and, hence, thermochemical recuperation is a high-efficiency variant of the utilization of secondary energy resources.

A Novel Method of Recycling CO 2 for Slag Splashing in Converter

Abstract Converter off-gas, an important energy resource for steel industries, is one of the weak points in the recovery and utilization of secondary energy resources. To improve the level of recycling converter off-gas in steel plants, a novel approach to the recycle of CO 2 separated from converter off-gas or other off-gas for the green slag splashing technique was developed, and the CO 2 equilibrium conversion ratio of the green CO 2 slag splashing under different technological conditions was calculated by the program of enthalpy (H), entropy (S), and heat capacity (C), i.e. HSC software. Furthermore, the experiments of CO 2 injected into molten converter slag were carried out, and the influencing factors of the green slag splashing technique using CO 2 were analyzed. The experimental results showed that the carbon content for smooth slag splashing using CO 2 was about 4.0%.

Power Supply and Energy Conservation in Fractional Distillation of Crude Oil

Different schemes of connecting distillation towers are examined: from separating subsystems with coupled heat flows to separating subsystems with linkages of towers for distillate or residue. The causes that prevent implementation of separation schemes with connected heat flows as subsystems with minimum power consumption for separation of multicomponent mixtures are revealed. A system is proposed for separation of crude oil as a multicomponent mixture into seven products with minimum consumption of primary energy resources due to maximum recovery and utilization of secondary energy resources. The use of combined separation schemes together with optimum subsystems for supplying and recovering thermal energy will eliminate terminal coolers—after—coolers and cooling agents.

Complex Optimization of Processes of Heat Exchange in Gas‐Firing Installations with Utilization of Heat

Results of complex experimental investigations of the processes of combustion and combined heat exchange with separation of radiative and convective components of boilers with utilization of secondary energy resources are presented. The complex optimization is conducted by solving a system of partial differential equations on EC, CM, and IBM computers. For the purpose of controlling the combustion and heat‐exchange processes automatically, the calculated dependences are given and charts of regimes are composed.

Utilization of secondary energy resources in chemical industry

The evaluation of chemical-technological processes is necessary from the point of view of raw-material use and energy efficiency. The development of new technological designs for energy utilization within the technological process is necessary. Often energy utilization requires modern equipment. A new profession must be created of industrial power engineering: power engineering for technological processes. This new profession should improve technological designs, not only for better energy utilization but also for construction of equipment for energy utilization. Often an increase in energy efficiency of technological processes requires higher investment cost, therefore economic evaluation is necessary. Several concrete examples (atmospheric crude oil distillation, new technological process NIVOL, new reesterification reactor, distillation column with tensile-metal-packing, hydrogen production by mazout gasification with oxygen and steam, propane-butane mixture production) demonstrate that chemical-technological research and machinery development of new chemical apparatus is a modern way to the utilization of secondary energy resources in the chemical industry.

Utilization of secondary energy resources to produce higher vacuums

A major reserve for savings in manufacturing is the use of secondary energy resources (SER) to produce refrigeration in absorption refrigeration units (ARU). One possible field of application of refrigeration is the development of the required vacuum in vacuum towers. This paper proposes a scheme for the production of refrigeration in the form of chilled water, using an ARU, by utilization of the SER of the head stream from the atmospheric tower of an ELOU-AVT-6 unit, with an intermediate heat carrier loop added to be able to use standardized ARUs.

Utilization of secondary energy resources in coke calcining units

This paper examines the status of secondary energy resources (SER), the utilization of which must be increased for the process of calcining petroleum cokes in a coke calcining unit in a hearth furnace at the Krasnovodsk refinery. A simplified flow chart of hot streams in the coke calcining unit is given. The efficiency of the unit can be increased by raising the off-gas temperature at the inlet to the design level, by improving the operating conditions of the boiler, and by redesigning the cooler.

Environmental protection and utilization of secondary energy resources

Environmental protection and utilization of secondary energy resources

Utilization of secondary energy resources in tunnel kilns

The conversion of the dryers to heating by flue gases has resulted in more stable thermal and aerodynamic conditions of a drying and heating in drying-firing units Nos. 4 and 5.