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

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.

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

Energy ◽

10.1016/j.energy.2008.02.006 ◽

2008 ◽

Vol 33 (6) ◽

pp. 882-889 ◽

Cited By ~ 29

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

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

Energies ◽

10.3390/en12061028 ◽

2019 ◽

Vol 12 (6) ◽

pp. 1028 ◽

Cited By ~ 3

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.

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

Energy and automation ◽

10.31548/energiya2021.02.039 ◽

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

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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

ASME 2005 Power Conference ◽

10.1115/pwr2005-50372 ◽

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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