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

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.

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.


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.


2007 ◽  
Vol 2007.12 (0) ◽  
pp. 181-182
Author(s):  
Hitoshi ASANO ◽  
Hikaru MORITA ◽  
Masato TANIMOTO ◽  
Yohei BABA ◽  
Yoshinori HISAZUMI ◽  
...  

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

2017 ◽  
Vol 53 (1) ◽  
Author(s):  
A. E. Denysova ◽  
G. V. Luzhanska ◽  
I. O. Bodnar ◽  
A. S. Denysova

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.


2004 ◽  
Vol 2004.39 (0) ◽  
pp. 44-45
Author(s):  
Takuro SAKAMAKI ◽  
Toshihiro HORIKI ◽  
Takumi HASHIZUME ◽  
Hirokazu YONEDA ◽  
Katsumi FUJIMA ◽  
...  

Energy ◽  
2008 ◽  
Vol 33 (6) ◽  
pp. 882-889 ◽  
Author(s):  
P KAPUSTENKO ◽  
L ULYEV ◽  
S BOLDYRYEV ◽  
A GAREV

Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 1028 ◽  
Author(s):  
Agata Rijs ◽  
Tomasz Mróz

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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