scholarly journals RANGE OF EXHAUST GASES PRE-COOLING IN THE IMPROVED HEAT PUMP SYSTEM OF HEAT SUPPLY

Author(s):  
V.D. Petrash ◽  
◽  
Yu.N. Polunin ◽  
N.V. Danichenko ◽  
◽  
...  

The paper studies the range of possible and rational pre-cooling of exhaust gases in an improved heat pump of heating supply system in the development of its previously proposed basic version. The research has established analytical dependences for determining the energy flows of the condenser and evaporator, as well as the energy efficiency of the improved heat supply system. On their basis, a rational range of preliminary cooling of exhaust gases of rotary kilns was revealed, the upper level of which is determined, first of all, by their initial temperature. It has been established that the rational ratio of water consumption for heating systems with traditional temperature drops and hot water supply is in the range of 0.3-0.9. At the same time, an increase in energy efficiency is noted in the process of operational regulation of systems with a decrease in the ratio of the costs of heat carriers for technological and household purposes. The degree of precooling of exhaust gases, which significantly depends on their initial temperature, is in the range of 0.35-0.5 with a decrease in the corresponding flow rates of heat carriers in heating and hot water supply systems. The rational ratio of the consumption of the heating and heated medium in the process of contact interaction, which significantly depends on the initial temperature of the exhaust gases, is in the range of 0.2-1.2. For low-temperature waste gases (up to 500С), the reciprocal values of the analyzed ratio logically agree with the corresponding values of the irrigation coefficient. The results of the analytical study established multifactorial dependences of energy flows in the condenser and evaporator, as well as determining the energy efficiency of an improved heat pump of the heat supply system, on the basis of which the general range of possible pre-cooling of exhaust gases from rotary kilns was revealed.

2021 ◽  
pp. 39-51
Author(s):  
M. Prokopov ◽  
◽  
S. Sharapov ◽  
Yu. Merzlyakov ◽  
D. Gusev ◽  
...  

The expediency of the implementation of the principle of steam thermal compression to improve the energy efficiency of sources of electricity and heat supply of small heat power engineering is substantiated. The results of thermodynamic analysis and numerical optimization of the parameters of the compressor steam-turbine cycle of a small cogeneration power plant are presented. A jet step-down thermotransformer has been tested - as an alternative to traditional boiler heating. On the basis of the conducted thermodynamic analysis, a new combined cycle of a step-down thermotransformer has been developed, which ensures efficient conversion of the supplied energy (mainly in the form of fuel heat) into the heat carrier flow of the heat supply system with the required temperature level 50 ... 90 °C). The fundamental difference between the considered thermal transformer and steam compressor heat pumps is the replacement of a mechanical compressor with a steam thermocompressor module (STC-unit). The working process in the STK-module is realized by using the liquid phase of the refrigerant, which boils up during expiration, subcooled to saturation, as an active medium of a jet compressor. Injection of steam from the evaporator is provided due to the fine-dispersed vapor-droplet structure formed in the outlet section of the active flow nozzle. A program for the numerical study of the working process of a step-down thermal transformer was prepared and tested, on the basis of which multivariate calculations were carried out. On the basis of computational studies, the area of achievable indicators of the proposed heat supply system has been established; the area of initial operating parameters corresponding to the maximum values of the conversion coefficient and exergy efficiency was determined; comparative indicators of the main parameters of the investigated thermal transformer on various working substances in the range of operating modes as a heat pump or a refrigerating machine were obtained. Key words: workflow, steam thermocompressor, step-down thermotransformer, energy efficiency, heat pump mode


Author(s):  
Hitoshi Asano ◽  
Terushige Fujii ◽  
Yoshinori Hisazumi ◽  
Toshihiro Hori ◽  
Tetsuo Abiko

In order for economically viable distributed generation systems for local community to spread, it is essential to develop an efficient and low-cost heat supply system. We propose a new heat supply system called DREAMS (Distributed Residential Energy with Advanced Management System). The key technology for the system is to connect compact heat supply units installed in all the households of the local community, such as a condominium, by a single loop of hot water piping. Two methods to decrease the heat supply rate through the single loop are proposed in this paper. The one is an utilization of a compact heat supply unit with heat storage in each house. The momentary heat demand can be covered by the heat storage. The other is a tap water preheating. A new CO2 regenerative heat pump cycle was proposed for the recover of the low temperature heat from the generator. A new heat supply unit with a practical capacity was manufactured, and the heat supply performance was evaluated by some experiments. Furthermore, an advanced energy management system has been under consideration to realize the effective system operation by utilizing IT. In this paper, experimental results on the performance of the new heat supply unit, the new CO2 heat pump system and evaluation of the energy-saving effect of our DREAMS are presented.


2021 ◽  
Vol 2(50) ◽  
Author(s):  
Vitaly Petrash ◽  
◽  
Vitaly Baryshev ◽  
Leonid Shevchenko ◽  
Elina Geraskina ◽  
...  

This work is devoted to the study of energy technological parameters of heat pump utilization of exhaust gases heat from rotary kilns in production of building materials for heat technology and industrial heat supply. This goal is achieved due to the proposed new approach to the crea-tion of energy-saving technology and improvement of the heat supply system based on the in-tegration of contact-recuperative and thermal transformer heat recovery. The most important results are as following: a modified dependence of the conversion coefficient, an effective system for removing the waste gas heat for industrial and urban heat supply, a thorough as-sessment of the energy efficiency of the developed system, the dependence of the actual con-version coefficient on the energy technological parameters, as well as a rational degree of the exhaust gases pre-cooling, depending on their initial temperature and ratio of water consump-tion of the systems for technological and household purposes, and the range of their preferred ratio. The relationship between the consumption of the heating and heated medium in the pro-cess of the contact interaction has been substantiated. The results obtained differ from those existing by the complex accounting of the energy technological parameters in the analytical so-lution of the task. The practical significance of the results of the proposed technical solution lies in the fact that they can significantly reduce the consumption of the burned fuel due to a substantial expansion of the energy potential of the recovered heat, reduce heat, dust and gas emissions.


2022 ◽  
Vol 2150 (1) ◽  
pp. 012033
Author(s):  
P V Rotov ◽  
R A Gafurov

Abstract The reliability and efficiency of the operation of district heating systems is largely determined by the efficiency of preparation of heating network water. In open heat supply systems, make-up water, among other things, compensates for the water intake in hot water supply systems. A number of technologies have been developed that increase the efficiency of an open heat supply system by reducing the water consumption in the supply pipeline of the heating network, increasing the operating time of the heat pump, and increasing the specific generation of electricity for heat consumption at the CHP plant due to additional cooling of the network water in the return pipe of the heating network.


Author(s):  
V. D. Petrash ◽  
V. O. Makarov ◽  
A. A. Khomenko

The results of the analytical study substantiated the operating conditions for the highly efficient use of the temperature potential of seawater in heat pump heating systems (HPHS) for buildings a building with correspondingly improved environmental indicators. Based on the analysis of the regional conditions of the Odessa water area of the Black Sea, the initial parameters have been substantiated and rational modes of operation of an improved HPHS with central, decentralized or local heating of the subscriber energy carrier have been determined. As indicators for evaluating the efficiency of the HPHS operation, the conversion factor of energy flows and the specific consumption of external energy for the drive of the compressor and the circulating pump of cooled water in the operation of heat pump units were considered. For seawater in the Odessa water area of the Black Sea during the entire heating period, the following temperatures were considered as initial data for analysis: water at the inlet to the evaporator (5–10) ° C, at the outlet (1 °C); calculated temperature difference of the coolant in the heating system (50–40) °C, indoor air (20 °C); estimated outdoor temperature (–18 °C). The characteristic correspondence between the flow rates of the cooled sea water and the heated energy carrier of the heat supply system was taken into account. The prerequisites of high efficiency of the heat pump heat supply system in which the actual conversion coefficient exceeds the seasonal normalized calculated and minimum value at an outdoor temperature of (–10) °C under the limiting conditions of the monoenergy regime for both new and reconstructed buildings were substantiated. In the course of the study, it has been determined that the total specific consumption of external energy for the compressor drive and the circulation of cooled water in the operation of a heat pump unit with a characteristic ratio of water equivalents, even under the limiting conditions of the monoenergetic mode of operation of the heat supply system at an outdoor temperature of (–10) °C, are within the range of generally accepted values (w = 0.28–0.34).


Vestnik IGEU ◽  
2019 ◽  
pp. 5-13
Author(s):  
V.V. Smirnov ◽  
Yu.V. Yavorovsky ◽  
V.V. Sennikov ◽  
D.O. Romanov

Analysis of the use of a thermo-hydraulic distributor in district heating schemes showed insufficient study of the mutual influence of the connected circuits, on which the coefficient of hydraulic stability of the heating network depends, and the lack of a comparative analysis of the efficiency of heat supply when using a scheme with a thermo-hydraulic distributor compared to widely used subscriber connection schemes. The purpose of the study is to compare the economic and energy efficiency of the proposed and existing subscriber connection schemes, which is an important task. In laboratory conditions, a wide range of studies have been carried out to study the hydraulic dependence of the contours of the thermo-hydraulic distributor among themselves. Processing of the results was carried out by the method of correlation-regression analysis and mathematical statistics. In a comparative analysis of subscriber connection schemes, methods of physical modeling of thermo-hydraulic modes were used. A comparative analysis showed that the energy efficiency of the scheme with a thermo-hydraulic distributor is higher in heating systems with non-automated subscribers, regardless of the temperature graph of the heating network. When comparing schemes with parallel connection of a hot water heater, it was found that the totality of electricity consumption for coolant circulation and fuel costs for a circuit with a thermo-hydraulic distributor turned out to be less irrespective of the temperature schedule. Statistical research methods confirmed the independence of the circuits and the normal supply of heat to the heating. New solutions have been obtained to increase the hydraulic stability of the centralized heat supply system using a thermo-hydraulic distributor at a heating point – the hydraulic stability coefficient of the heat network during all subscriber operation modes is equal to one. The results of the study can be used in the design of thermal points: the proposed heating system, the consumers of which will provide a stable hydraulic mode; existing heat supply system, the consumers of which must ensure the hydro-stable control of heat.


Author(s):  
Tetiana Zheliuk

Introduction. One of the main directions of ensuring the sustainable development of the national economy and its regions is the reform of the energy sector, which can take place through the modernization or innovation of its components. An important component of these reforms is to provide the population with the environmentally friendly and socially safe thermal energy. At the present stage of management, the heat supply is the most costly branch of public utilities, which is supplemented by the problems of the inefficient fuel balance structure; worn-out infrastructure and low energy efficiency. This highlights the need to study the management of modernization of the heat supply system in the region in view of the declared vectors of the long-term development. Object of research is the process of managing the modernization of the heat supply system in the region. Subject of the research is a set of scientific approaches and practical mechanisms of modernization of the heat supply system of the region in the context of ensuring its sustainable development. Objective. The conceptual foundations of modernization of the heat supply system of the region in the context of its sustainable development through the introduction of the innovative technologies both in the management process and in the energy sector itself is substantiated in the paper. Methods. The following general scientific methods were used during the research process: system, structural analysis, grouping, when studying the structural elements and isolation of problems of development of the heat supply system of the region; historical analysis, when considering the scientific principles and institutional mechanism of modernization of the region’s heat supply system; comparative analysis in assessing the possibilities of the green transition of the heat supply system of the region and also when considering the features of the use of grant resources in the modernization of the heat supply system of the region; economic analysis in assessing the current state of the district heating system, etc. results. The essential determinants of the heat supply system of the region are analyzed, the objective need, organizational and economic mechanisms for managing the modernization of the heat supply, taking into account the need for the balanced development of the energy sector of the region are verified. The scientific novelty of the obtained results lies in the substantiation of the conceptual approaches to the management of modernization of the heat supply system of the region by innovating the forms and methods of managerial influence on the heat supply system of the region. The conclusion is made about the following effective approaches in managing the modernization of the district heating system: planning of the sustainable development of the energy sector, development of programs for modernization of the district heating, implementation of the infrastructure and soft projects, implementation of the international projects, motivation of households and entrepreneurship in the heat sector, participation in the grant requests, in state crediting programs, realization of the business projects in the field of production of environmentally friendly fuel; conducting an information campaign among the population and other key market players to raise the awareness of the energy efficiency financing mechanisms. The practical significance of the obtained results is that the developed recommendations will be used to improve the organizational and economic mechanism of management of the district heating system modernization and ensure its sustainable development.


2002 ◽  
Vol 2002 (0) ◽  
pp. 347-348
Author(s):  
Masaharu KATO ◽  
Takuro SAKAMAKI ◽  
Takumi HASHIZUME ◽  
Hirokazu YONEDA ◽  
Katsumi FUJIMA ◽  
...  

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