scholarly journals ŠILUMOS SIURBLIŲ INTEGRAVIMO Į ORO RUOŠTUVUS ENERGINĖ ANALIZĖ / ENERGY EFFICIENCY GAIN OF HEAT PUMP INTEGRATION IN AIR HANDLING UNITS

2018 ◽  
Vol 10 (0) ◽  
pp. 1-5
Author(s):  
Kęstutis Čiuprinskas ◽  
Vilius Šipulskis
Keyword(s):  
Heat Pump ◽  
Energy Use ◽  
Heat Pumps ◽  
External Heat ◽  
Efficiency Gain ◽  
Air Temperatures ◽  
Economical Evaluation ◽  
Air Handling Units ◽  
Measured Efficiency ◽  
Efficiency Indicators

This article describes how heat pumps (HP) integrated in air handling units (AHU) proud against the analogous AHU with external heat pumps. Two almost identical (except heat pump position) air handling units were analysed. During the experimental study supply and return air temperatures and AHU’s fans power were measured. Efficiency indicators and consumed energy were calculated based on measured data. Seasonal performance factor (SCOP) and total annual energy use was evaluated for both units. During the economical evaluation was found, that AHU with integrated HP can payback within 10 years compared with AHU combined with external heat pump. Santrauka Straipsnyje nagrinėjama, kiek šilumos siurbliai, integruoti į oro ruoštuvus, yra pranašesni už analogiškus išorinius šilumos siurblius. Nagrinėjami du realiomis sąlygomis veikiantys analogiški oro ruoštuvai – vienas su integruotu, o kitas su išoriniu šilumos siurbliu. Tyrimo metu išmatuotos šių įrenginių rodiklių vertės, lemiančios jų energinį naudingumą, tokios kaip oro temperatūra ir vartojama energija. Tam, kad galima būtų nustatyti sezoninį įrenginių efektyvumą (SCOP), šie rodikliai pagal LST EN14825:2016 buvo matuojami esant skirtingai aplinkos temperatūrai. Nustatyti išvestiniai efektyvumo rodikliai bei, remiantis standartu, apskaičiuotas abiejų įrenginių šilumos siurblių efektyvumas. Lyginant pradinių investicijų ir šildymo sezono energijos kaštų skirtumus, įvertintas oro ruoštuvų su integruotais šilumos siurbliais ekonominis naudingumas.

Expediency of substitution of water heating with air heating involving use of heat pumps

2019 ◽  
Vol 12 (1) ◽  
pp. 45-49
Author(s):  
A. V. Martynov ◽  
N. E. Kutko
Keyword(s):  
Heat Pump ◽  
Ambient Air ◽  
Heat Pumps ◽  
Low Grade ◽  
Heating Season ◽  
Water Heating ◽  
Heating Systems ◽  
Air Heating ◽  
Transformation Ratio ◽  
Air Temperatures

Expediency is considered of substitution of water heating and transition to air heating that can be implemented with “air-air” type heat pumps (HP). The absence of water pipelines raises the reliability of heating systems. In addition to improved reliability, heat pumping systems ensure comfortable conditions for consumers at intervals between the heating seasons, when the central water heating is disabled.The “air-air” type HP use the ambient air as a low-grade heat source (LGHS). At low air temperatures, transformation ratio μ is about 2 and would rise to 3÷4 at higher air temperatures, which ensures high cost-efficiency of heating systems based on heat pumps. The heating season can generally be divided into two periods. One of the periods is characterized by the highest ambient air temperatures (–5÷8°С). This period is rather long and, in warmer winters, can last for about 4000 hours per heating season, or longer. This is the period, when the heat pump operates efficiently at a transformation ratio above 4.The other period, when the ambient temperature falls below –10÷ –20°С, generally lasts for a small number of hours, which makes about 15÷18% of the total duration of the heating season. At this period, the efficiency of the heat pump would decrease to μ =1.9÷2. Yet, even with such an efficiency, a heat pump delivers twice as much heat as the electric power it consumes.Therefore, in regions with a long period of temperatures within the range of –5÷8°С during a heating season, air heating based on HP can be advantageous compared to water heating.

scholarly journals EXPERIMENTAL TEST STAND OF A HEAT PUMP INTEGRATED IN AIR HANDLING UNIT

2020 ◽  
Vol 12 (0) ◽  
pp. 1-6
Author(s):  
Anton Frik ◽  
Juozas Bielskus
Keyword(s):  
Heat Pump ◽  
Scientific Literature ◽  
Thermodynamic Cycle ◽  
Heat Pumps ◽  
Theoretical Studies ◽  
Experimental Stand ◽  
Air Handling Unit ◽  
Air Handling Units ◽  
And Control ◽  
Installation Cost

Heat pumps are becoming increasingly popular and are playing an important role in the heat and cooling supply chain of buildings sector. Although more than 160 years have passed since the manufacture of the first heat pump, this technology, designed to recover low­potential heat energy and its useful use, can be called an innovative and efficient energy transformer. Air­to­water and air­to­air heat pumps are becoming more popular today due to their installation cost compared to ground­to­water heat pumps. It has been noticed that recently air­to­air heat pumps are more often installed in modern air handling units. The main energy transformers in these air handling units are the air­to­air heat pump and recovery heat exchanger. In the scientific literature little attention is paid to the thermodynamic cycle of the combination of the air handling unit and the heat pump, as well as the search for new possibilities to change and control it, this is a potential direction that can increase the efficiency of the whole system. To study the control capabilities of the unit, an experimental stand of the heat pump built into the ventilation unit is needed; it would help validate the results of theoretical studies and investigate the possibilities of expanding the control. Therefore, this paper presents a review of the experimental stands of non­integrated heat pumps and integrated heat pumps in air handling unit. Based on this review, the basic requirements for the installation of an experimental stand of a heat pump built into an air handling unit are formulated and a conceptual scheme of this stand is drawn up.

scholarly journals ENERGY EFFICIENCY IN CONSTANTA HARBOR- A THEORETICAL ASSESSMENT OF THE PERFORMANCE OF A HEAT PUMP FOR HEATING NEEDS, FOR A LESS POLLUTANT ADMINISTRATION OFFICE

2021 ◽  
Vol 2021 (2) ◽  
pp. 33-38
Author(s):  
FEIZA MEMET
Keyword(s):  
Heat Pump ◽  
Air Temperature ◽  
Fossil Fuels ◽  
Heat Pumps ◽  
Coefficient Of Performance ◽  
Electrical Heating ◽  
Outdoor Air ◽  
Heated Water ◽  
Air Temperatures ◽  
Discharge Temperature

In accordance with the present energetic exigencies, the energy consumption in port buildings is of a vital importance. From this perspective, heat pumps are less pollutant and more energy efficient options than the traditional heating technologies. This study focuses on an air source heat pump (ASHP), operating in an administration office located in Constanta harbor, Romania, in order to supply heated water during December of 2020. Electrically driven heat pumps are seen as a successful alternative to classical expensive heating means, such as electrical heating or the one based on fossil fuels combustion. Within this research, are investigated influences of the heated water temperatures and exterior air temperatures on the theoretical Coefficient of Performance, the compression ratio and the discharge temperature. The cycle is working with R134a, with 50C superheating and sub cooling. It will be considered that the heated water is supplied in the range (40-50) 0C, while the outdoor air temperature varies in the range (0-10) 0C. Obtained results show that the highest efficiency of the ASHP is obtained for the lowest value of the heated water temperature and for the highest value of the outdoor air temperature. This situation corresponds also to the good working of the compressor of the refrigeration plant, since are seen lowest values of the compression rate and the discharge temperature, as well. This means that the compressor do not consume high amounts of energy and the oil is not damaged because of high temperatures of the refrigerant vapors.

Saving Primary Energy Consumption Through Exergy Analysis of Combine Distillation and Power Plant

2012 ◽  
Vol 9 (2) ◽  
pp. 65
Author(s):  
Alhassan Salami Tijani ◽  
Nazri Mohammed ◽  
Werner Witt
Keyword(s):  
Energy Consumption ◽  
Power Plant ◽  
Heat Pump ◽  
Heat Recovery ◽  
Energy Savings ◽  
Primary Energy ◽  
Heat Pumps ◽  
Saturated Steam ◽  
Distillation Unit ◽  
Primary Energy Consumption

Industrial heat pumps are heat-recovery systems that allow the temperature ofwaste-heat stream to be increased to a higher, more efficient temperature. Consequently, heat pumps can improve energy efficiency in industrial processes as well as energy savings when conventional passive-heat recovery is not possible. In this paper, possible ways of saving energy in the chemical industry are considered, the objective is to reduce the primary energy (such as coal) consumption of power plant. Particularly the thermodynamic analyses ofintegrating backpressure turbine ofa power plant with distillation units have been considered. Some practical examples such as conventional distillation unit and heat pump are used as a means of reducing primary energy consumption with tangible indications of energy savings. The heat pump distillation is operated via electrical power from the power plant. The exergy efficiency ofthe primary fuel is calculated for different operating range ofthe heat pump distillation. This is then compared with a conventional distillation unit that depends on saturated steam from a power plant as the source of energy. The results obtained show that heat pump distillation is an economic way to save energy if the temperaturedifference between the overhead and the bottom is small. Based on the result, the energy saved by the application of a heat pump distillation is improved compared to conventional distillation unit.

Technical Note. Influence of Material Used for the Regenerator on the Properties of a Thermoacoustic Heat Pump

2013 ◽  
Vol 38 (4) ◽  
pp. 565-570 ◽  
Author(s):  
Bartłomiej Kruk
Keyword(s):  
Heat Transfer ◽  
Temperature Gradient ◽  
Acoustic Wave ◽  
Heat Pump ◽  
Sound Wave ◽  
Heat Exchangers ◽  
Heat Pumps ◽  
Technical Note ◽  
New Materials ◽  
Modern Technologies

Abstract Research in termoacoustics began with the observation of the heat transfer between gas and solids. Using this interaction the intense sound wave could be applied to create engines and heat pumps. The most important part of thermoacoustic devices is a regenerator, where press of conversion of sound energy into thermal or vice versa takes place. In a heat pump the acoustic wave produces the temperature difference at the two ends of the regenerator. The aim of the paper is to find the influence of the material used for the construction of a regenerator on the properties of a thermoacoustic heat pump. Modern technologies allow us to create new materials with physical properties necessary to increase the temperature gradient on the heat exchangers. The aim of this paper is to create a regenerator which strongly improves the efficiency of the heat pump.

DETERMINING THE PROFITABILITY OF GREENHOUSE ELECTROTECHNOLOGIES: A MODELING APPROACH

HortScience ◽  
1994 ◽  
Vol 29 (4) ◽  
pp. 249a-249
Author(s):  
Eric A. Lavoie ◽  
Damien de Halleux ◽  
André Gosselin ◽  
Jean-Claude Dufour
Keyword(s):  
Energy Consumption ◽  
Heat Pump ◽  
Water System ◽  
Heat Pumps ◽  
Hot Water ◽  
Pump System ◽  
Heat Pump System ◽  
Artificial Lighting ◽  
Hot Air ◽  
Marketable Fruit

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.

Buildings

2017 ◽  
Author(s):  
Peter Rez
Keyword(s):  
Heat Transfer ◽  
Heat Pump ◽  
Energy Efficient ◽  
Energy Use ◽  
Fossil Fuel ◽  
Local Climate ◽  
Heating And Cooling ◽  
The Difference ◽  
As If

Most of the energy used by buildings goes into heating and cooling. For small buildings, such as houses, heat transfer by conduction through the sides is as much as, if not greater than, the heat transfer from air exchanges with the outside. For large buildings, such as offices and factories, the greater volume-to-surface ratio means that air exchanges are more significant. Lights, people and equipment can make significant contributions. Since the energy used depends on the difference in temperature between the inside and the outside, local climate is the most important factor that determines energy use. If heating is required, it is usually more efficient to use a heat pump than to directly burn a fossil fuel. Using diffuse daylight is always more energy efficient than lighting up a room with artificial lights, although this will set a limit on the size of buildings.

scholarly journals Local Heating Networks with Waste Heat Utilization: Low or Medium Temperature Supply?

Energies ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 954 ◽  
Author(s):  
Hanne Kauko ◽  
Daniel Rohde ◽  
Armin Hafner
Keyword(s):  
Low Temperature ◽  
Heat Pump ◽  
Urban Areas ◽  
Waste Heat ◽  
Local Heating ◽  
District Heating ◽  
Heat Pumps ◽  
Hot Water ◽  
Local Network ◽  
Medium Temperature

District heating enables an economical use of energy sources that would otherwise be wasted to cover the heating demands of buildings in urban areas. For efficient utilization of local waste heat and renewable heat sources, low distribution temperatures are of crucial importance. This study evaluates a local heating network being planned for a new building area in Trondheim, Norway, with waste heat available from a nearby ice skating rink. Two alternative supply temperature levels have been evaluated with dynamic simulations: low temperature (40 °C), with direct utilization of waste heat and decentralized domestic hot water (DHW) production using heat pumps; and medium temperature (70 °C), applying a centralized heat pump to lift the temperature of the waste heat. The local network will be connected to the primary district heating network to cover the remaining heat demand. The simulation results show that with a medium temperature supply, the peak power demand is up to three times higher than with a low temperature supply. This results from the fact that the centralized heat pump lifts the temperature for the entire network, including space and DHW heating demands. With a low temperature supply, heat pumps are applied only for DHW production, which enables a low and even electricity demand. On the other hand, with a low temperature supply, the district heating demand is high in the wintertime, in particular if the waste heat temperature is low. The choice of a suitable supply temperature level for a local heating network is hence strongly dependent on the temperature of the available waste heat, but also on the costs and emissions related to the production of district heating and electricity in the different seasons.

Experimental investigation on water quality standard of Yangtze River water source heat pump

2012 ◽  
Vol 66 (5) ◽  
pp. 1103-1109 ◽  
Author(s):  
Zenghu Qin ◽  
Mingwei Tong ◽  
Lin Kun
Keyword(s):  
Water Quality ◽  
Surface Water ◽  
River Water ◽  
Heat Pump ◽  
Yangtze River ◽  
Water Source ◽  
Quality Standard ◽  
Heat Pumps ◽  
The Yangtze River ◽  
Water Conditions

Due to the surface water in the upper reaches of Yangtze River in China containing large amounts of silt and algae, high content of microorganisms and suspended solids, the water in Yangtze River cannot be used for cooling a heat pump directly. In this paper, the possibility of using Yangtze River, which goes through Chongqing, a city in southwest China, as a heat source–sink was investigated. Water temperature and quality of the Yangtze River in the Chongqing area were analyzed and the performance of water source heat pump units in different sediment concentrations, turbidity and algae material conditions were tested experimentally, and the water quality standards, in particular surface water conditions, in the Yangtze River region that adapt to energy-efficient heat pumps were also proposed. The experimental results show that the coefficient of performance heat pump falls by 3.73% to the greatest extent, and the fouling resistance of cooling water in the heat exchanger increases up to 25.6% in different water conditions. When the sediment concentration and the turbidity in the river water are no more than 100 g/m3 and 50 NTU respectively, the performance of the heat pump is better, which can be used as a suitable river water quality standard for river water source heat pumps.

scholarly journals Selection of Heat Pump Capacity Used at Thermal Power Plants under Electricity Market Operating Conditions

Energies ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 226
Author(s):  
Milana Treshcheva ◽  
Irina Anikina ◽  
Vitaly Sergeev ◽  
Sergey Skulkin ◽  
Dmitry Treshchev
Keyword(s):  
Electric Power ◽  
Heat Pump ◽  
Heat Load ◽  
Power Plants ◽  
Thermal Power ◽  
Heat Pumps ◽  
Operating Conditions ◽  
Energy Resources ◽  
Thermal Power Plants ◽  
Maximum Heat

The percentage of heat pumps used in thermal power plants (TPPs) in the fuel and energy balance is extremely low in in most countries. One of the reasons for this is the lack of a systematic approach to selecting and justifying the circuit solutions and equipment capacity. This article aims to develop a new method of calculating the maximum capacity of heat pumps. The method proposed in the article has elements of marginal analysis. It takes into account the limitation of heat pump capacity by break-even operation at electric power market (compensation of fuel expenses, connected with electric power production). In this case, the heat pump’s maximum allowable capacity depends on the electric capacity of TPP, electricity consumption for own needs, specific consumption of conditional fuel for electricity production, a ratio of prices for energy resources, and a conversion factor of heat pump. For TPP based on combined cycle gas turbine (CCGT) CCGT-450 with prices at the Russian energy resources markets at the level of 2019, when operating with the maximum heat load, the allowable heat pump capacity will be about 50 MW, and when operating with the minimum heat load—about 200 MW.

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