scholarly journals The Efficiency of Vapor Compression Transformation of Energy Flows for Heat Supply Based on the Sea Water

2021 ◽  
Vol 64 (6) ◽  
pp. 538-558
Author(s):  
V. D. Petrash ◽  
V. O. Makarov ◽  
A. A. Khomenko
Keyword(s):  
Heat Pump ◽  
Heat Supply ◽  
Sea Water ◽  
Heat Supply System ◽  
Water Area ◽  
Supply System ◽  
The Black Sea ◽  
Outdoor Temperature ◽  
External Energy ◽  
Energy Flows

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).

scholarly journals Exergy Evaluation of a Heat Supply System with Vapor Compression Heat Pumps

Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 1028 ◽  
Author(s):  
Agata Rijs ◽  
Tomasz Mróz
Keyword(s):  
Heat Pump ◽  
Heat Supply ◽  
Heat Supply System ◽  
Heat Pumps ◽  
Supply System ◽  
Exergy Efficiency ◽  
Vapor Compression ◽  
Outdoor Temperature ◽  
Pump System ◽  
Heat Pump System

The vapor compression heat pumps are very popular solutions regarding heat supply systems of modern, low energy buildings. It is partly due to the fact that they are treated as a sustainable heat supply. The question arises: Can a vapor compression heat pump be treated as a sustainable heat supply? To answer this question; the exergy model of a heat pump system operation has been proposed. The proposed model has been employed for evaluation of exergy efficiency of an existing heat supply system equipped with two heat pumps installed in an educational building located on the campus of Poznan University of Technology, Poznan, Poland. The analysis shows that the system exergy efficiency decreases with an increase in outdoor temperature and its values are in the range of 10.9% to 42.0%. The primary exergy efficiency, which considers the conversion of fossil fuel into electricity, is on average 3.2 times lower than the system exergy efficiency for the outdoor temperature range of −9 °C to 11 °C. The performed analysis allowed for the identification of a set of solutions that may increase the exergy and primary exergy efficiency of the system. The first solution is to cover a part of the electricity demand by a renewable energy source. The second proposition is to apply a low-temperature emission system for heating. The third idea is to apply a district heating network as the heat supply instead of the heat pump. The conclusion is that the exergy performance of systems with heat pumps is rather poor because they generate low-quality heat from high-quality electricity. The best way to improve the primary exergy efficiency of a heat pump system is to power the system by electricity generated from a renewable energy source.

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

2021 ◽  
pp. 139-147
Author(s):  
V.D. Petrash ◽  
◽  
Yu.N. Polunin ◽  
N.V. Danichenko ◽  
◽  
...  
Keyword(s):  
Energy Efficiency ◽  
Heat Pump ◽  
Heat Supply ◽  
Initial Temperature ◽  
Heat Supply System ◽  
Supply System ◽  
Hot Water ◽  
Exhaust Gases ◽  
Energy Flows ◽  
Rotary Kilns

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.

scholarly journals Study of the Total Heat Supply System Using CO2-Heat Pump : Part 3 Effect of the Division of Gas Cooler (1)

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

scholarly journals TWO-STAGE HEAT PUMPS FOR ENERGY SAVING TECHNOLOGIES

2017 ◽  
Vol 53 (1) ◽  
Author(s):  
A. E. Denysova ◽  
G. V. Luzhanska ◽  
I. O. Bodnar ◽  
A. S. Denysova
Keyword(s):  
Energy Saving ◽  
Heat Pump ◽  
Heat Supply ◽  
High Efficiency ◽  
Heat Supply System ◽  
Heat Pumps ◽  
Supply System ◽  
Alternative Methods ◽  
Ground Waters ◽  
Two Stages

The problem of energy saving becomes one of the most important in power engineering. It is caused by exhaustion of world reserves in hydrocarbon fuel, such as gas, oil and coal representing sources of traditional heat supply. Conventional sources have essential shortcomings: low power, ecological and economic efficiencies, that can be eliminated by using alternative methods of power supply, like the considered one: low-temperature natural heat of ground waters of on the basis of heat pump installations application. The heat supply system considered provides an effective use of two stages heat pump installation operating as heat source at ground waters during the lowest ambient temperature period. Proposed is a calculation method of heat pump installations on the basis of groundwater energy. Calculated are the values of electric energy consumption by the compressors’ drive, and the heat supply system transformation coefficient µ for a low-potential source of heat from ground waters allowing to estimate high efficiency of two stages heat pump installations.

122 Study of the Total Heat Supply System Using CO2-Heat Pump : Part 5 Heat Transfer Characteristics of a Gas Cooler

2004 ◽  
Vol 2004.39 (0) ◽  
pp. 44-45
Author(s):  
Takuro SAKAMAKI ◽  
Toshihiro HORIKI ◽  
Takumi HASHIZUME ◽  
Hirokazu YONEDA ◽  
Katsumi FUJIMA ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Pump ◽  
Heat Supply ◽  
Heat Supply System ◽  
Supply System ◽  
Total Heat ◽  
Heat Transfer Characteristics ◽  
Transfer Characteristics

Integration of a heat pump into the heat supply system of a cheese production plant

Energy ◽  
2008 ◽  
Vol 33 (6) ◽  
pp. 882-889 ◽  
Author(s):  
P KAPUSTENKO ◽  
L ULYEV ◽  
S BOLDYRYEV ◽  
A GAREV
Keyword(s):  
Heat Pump ◽  
Heat Supply ◽  
Heat Supply System ◽  
Supply System ◽  
Production Plant ◽  
Cheese Production

scholarly journals The energy efficiency concept and implementation prospects of the jet thermocompression principle in small heat energy

2021 ◽  
pp. 39-51
Author(s):  
M. Prokopov ◽  
◽  
S. Sharapov ◽  
Yu. Merzlyakov ◽  
D. Gusev ◽  
...  
Keyword(s):  
Energy Efficiency ◽  
Heat Pump ◽  
Thermodynamic Analysis ◽  
Heat Supply ◽  
Heat Supply System ◽  
Supply System ◽  
Combined Cycle ◽  
Working Process ◽  
Step Down ◽  
Thermal Transformer

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

Development of Single Loop Heat Supply System for Local Community Cogeneration: Prototype Test of a Heat Supply Unit With Heat Storage and Tap Water Preheating by Heat Pump Unit

2005 ◽  
Author(s):  
Hitoshi Asano ◽  
Terushige Fujii ◽  
Yoshinori Hisazumi ◽  
Toshihiro Hori ◽  
Tetsuo Abiko
Keyword(s):  
Heat Pump ◽  
Management System ◽  
Heat Supply ◽  
Local Community ◽  
Heat Storage ◽  
Tap Water ◽  
Heat Supply System ◽  
Supply System ◽  
Hot Water ◽  
Single Loop

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.

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