scholarly journals Digital technological model of heat exchange control in an air heat pump in a low-rise building

2021 ◽  
Vol 2131 (5) ◽  
pp. 052080
Author(s):  
S V Fedosov ◽  
V N Fedoseev ◽  
V A Emelin ◽  
S A Loginova

Abstract The use of air source heat pumps together with other renewable energy devices and highly efficient heating equipment together with digital control systems is a promising European trend that continues to grow in the face of rising prices for traditional energy sources. The article presents a number of technical energy-saving solutions, such as a mixing chamber for HVH, built into the heat supply system and the use of a supply and exhaust ventilation system, in which the principle of recuperation is incorporated. A digital modular-functional-structural diagram of heat generation of a heat carrier from the environment is proposed. Relying on the energy efficiency of the circuit design with an electric boiler, a buffer tank and a patented mixing chamber, the authors achieve a rationally controlled heat and air exchange of a combined heat pump system for heating premises. Automation of the joint work of rationally selected elements of the heat pump air system is one of the Smart Home technologies that improve the efficiency of heat supply, create comfortable living conditions and safety through digitalization of the control algorithm for this system.

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.


2021 ◽  
Vol 246 ◽  
pp. 06001
Author(s):  
Petri Pylsy ◽  
Jarek Kurnitski

The energy efficiency of existing apartment buildings is playing an important role in energy and climate targets. In Finland, mechanical exhaust ventilation system is commonly used in older apartment buildings. Hence, there could be an energy saving potential by an exhaust air heat pump system (EAHP). In this work two cases have been studied. Buildings were built in 1960’s and 1970’s and in renovation equipped with hybrid heating system: district heating and exhaust air heat pump system. Two years measurement data, 2018 and 2019, was collected to evaluate the performance of exhaust air heat pump systems. According to measurement data the monthly coefficient of performance (COP) was calculated as well as seasonal coefficient of performance (SCOP) was defined. The monthly COP values varied from 3,1 to 4,6 and SCOP values were about 3,7. Heating energy cost savings were 23-31 %. Energy performance class before and after EAHP installation was calculated. If at least 50 % of heating energy consumption was covered by EAHP then also energy performance class was improved.


HortScience ◽  
1994 ◽  
Vol 29 (4) ◽  
pp. 249a-249
Author(s):  
Eric A. Lavoie ◽  
Damien de Halleux ◽  
André Gosselin ◽  
Jean-Claude Dufour

The main objective of this research was to produce a simulated model that permitted the evaluation of operating costs of commercial greenhouse tomato growers with respect to heating methods (hot air, hot water, radiant and heat pumps) and the use of artificial lighting for 1991 and 1992. This research showed that the main factors that negatively influence profitability were energy consumption during cold periods and the price of tomatoes during the summer season. The conventional hot water system consumed less energy than the heat pump system and produced marketable fruit yields similar to those from the heat pump system. The hot water system was generally more profitable in regards to energy consumption and productivity. Moreover, investment costs were less; therefore, this system gives best overall financial savings. As for radiant and hot air systems, their overall financial status falls between that of the hot water system and the heat pump. The radiant system proved to be more energy efficient that the hot air system, but the latter produced a higher marketable fruit yield over the 2-year study.


2019 ◽  
Vol 38 (1) ◽  
pp. 201-221 ◽  
Author(s):  
Tianfu Xu ◽  
Fengyu Li ◽  
Bo Feng ◽  
Guanhong Feng ◽  
Zhenjiao Jiang

Shallow geothermal energy is stable and clean. Using a heat pump to produce groundwater and realize heating and cooling can effectively prevent haze and reduce energy consumption. To reduce engineering costs, many buildings in Beijing, China, plan to utilize single-well groundwater source heat pumps. Numerical modeling is an effective way to gain an understanding of thermal transport processes. However, wellbore-reservoir coupling and the uncertainty of productivity due to geological parameters make simulation difficult. A wellbore-reservoir-integrated fluid and heat transport model is defined by T2Well simulator to predict the productivity of a typical single-well system, with consideration of complex geological factors. The model is validated by the analytical model developed in Beijing, China. The fluid processes in the wellbore are described by 1 D non-Darcy flow, and the reservoir 3 D fluid and heat transport processes are calculated. Six crucial factors satisfying a random distribution are used, and for a single well that can supply heat for an area of 9000 m2, the output temperature during the heating season ranges from 11°C to 15°C.


2005 ◽  
Vol 128 (1) ◽  
pp. 28-34 ◽  
Author(s):  
Onder Ozgener ◽  
Arif Hepbasli

The main objective in doing the present study is twofold, namely (i) to review briefly the utilization of geothermally heated greenhouses and geothermal heat pumps in Turkey, since the system studied utilizes both renewable energy resources and (ii) to present the Analytical Hierarchy Process (AHP) as a potential decision making method for use in a greenhouse integrated solar assisted geothermal heat pump system (GISAGHPS), which was installed in the Solar Energy Institute of Ege University, Izmir, Turkey. This investigation may also be regarded as the one of the limited studies on the application of the AHP method to GISAGHPs, as no studies on the GISAGHPS have appeared in the literature. In this context, an economic analysis is performed based on the life cycle costing technique first. The results are then evaluated by applying the AHP method to a study, which is a comparative study on the GISAGHPS and split system. The results indicated that the GISAGHPS is economically preferable to the conventional split heating/cooling system under Turkey’s conditions.


Author(s):  
Masahito Oguma ◽  
Takeshi Matsumoto ◽  
Takao Kakizaki

Feasibility of a ground source heat pump (GSHP) system with pile heat exchangers for use in houses is evaluated through a numerical simulation. This GSHP system differs from ordinary borehole-type GSHP systems because short foundation piles installed at close intervals are used as heat exchangers. It is shown that the annual heat supply provided by this GSHP system is able to satisfy the demand of a house due to the air-source exchange at ground surface.


2021 ◽  
Vol 289 ◽  
pp. 05005
Author(s):  
Ivan Sokolov ◽  
Artem Ryzhenkov ◽  
Elizaveta Tyabut

The climatic conditions in Moscow limit to a certain extent the utilization of renewable energy sources for heat supply. Long heating period, relatively low average daily sunshine hours during heating period, and low outside temperatures act as barriers to realising the full potential of renewable energy sources. The paper presents an evaluation of feasibility and effectiveness of using various renewable energy sources in the heat supply system of Block 23 of the National research university «MPEI». The system arrangement for heat supply of the building with renewable energy sources is described. Experimental data have been obtained on the basis of this system. The calculated time dependences of building heat consumption and heat pump system (HPS) outputs are given. In addition, for the air-source heat pump system, the dependence on the outdoor temperature is given. Values of HPS efficiency indices are also presented. A comparative analysis of the efficiency of air-source HPS and liquid-to-liquid HPS with a geothermal circuit in winter conditions is carried out.


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.


Sign in / Sign up

Export Citation Format

Share Document