scholarly journals New Low-Temperature Central Heating System Integrated with Industrial Exhausted Heat Using Distributed Electric Compression Heat Pumps for Higher Energy Efficiency

Energies ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 6582
Author(s):  
Fangtian Sun ◽  
Yonghua Xie ◽  
Svend Svendsen ◽  
Lin Fu
Keyword(s):  
Energy Efficiency ◽  
Low Temperature ◽  
Heat Source ◽  
Thermal Performance ◽  
Heating System ◽  
Heat Pumps ◽  
Payback Period ◽  
Coefficient Of Performance ◽  
Financial Benefit ◽  
Central Heating

Industrial exhausted heat can be used as the heat source of central heating for higher energy efficiency. To recover more industrial exhausted heat, a new low-temperature central heating system integrated with industrial exhausted heat using distributed electric compression heat pumps is put forward and analyzed from the aspect of thermodynamics and economics. The roles played by the distributed electric compression heat pumps in improving both thermal performance and financial benefit of the central heating system integrated with industrial exhausted heat are greater than those by the centralized electric compression heat pumps. The proposed low-temperature central heating system has higher energy efficiency, better financial benefit, and longer economical distance of transmitting exhausted heat, and thus, its configuration is optimal. For the proposed low-temperature central heating system, the annual coefficient of performance, annual product exergy efficiency, heating cost, and payback period are about 22.2, 59.4%, 42.83 ¥/GJ, and 6.2 years, respectively, when the distance of transmitting exhausted heat and the price of exhausted heat are 15 km and 15 ¥/GJ, respectively. The economical distance of transmitting exhausted heat of the proposed low-temperature central heating system could approach 25.1 km.

scholarly journals Energy Saving Measures and Simulation in the Library Building of University of Surabaya

2018 ◽  
Vol 3 (1) ◽  
pp. 63
Author(s):  
Elieser Tarigan
Keyword(s):  
Energy Efficiency ◽  
Energy Saving ◽  
Thermal Performance ◽  
Heating System ◽  
Building Energy ◽  
Payback Period ◽  
Simulation Software ◽  
Efficient Technology ◽  
Radiant Cooling ◽  
Shading Devices

The rapid rate use of fossil fuels globally results in many environmental problems. The adoption of energy efficient technology has the potential to substantially reduce the amount of energy used in buildings. This paper discuses the energy saving measures and simulation for a six-floor library building, University of Surabaya, Indonesia. Simulation was carried out using the Excellence in Design for Greater Efficiency (EDGE) simulation software. The results of simulation showed that 53% of energy efficiency can be reached, without lowering of the building comfort, by applying of four measures at the same time are daylight photoelectric sensors for internal spaces (OFE29), radiant cooling and heating system (OFE16), higher thermal performance glass (OFE8), and external shading devices (OFE4). The implementation of the four measures would result in reduction of 758 ton of CO2/year with a payback period of 2.2 years.Keywords: Energy efficiency, energy building, energy saving, library building, energy simulation Pemanfaatan energy fosil dalam jumlah yang besar secara global menimbulkan permasalahan berkaitan dengan lingkungan. Usaha untuk mengimplementasikan teknologi dalam penghematan energi sangat signifikan dalam penerapannya pada bangunan. Tulisan ini mendiskusikan parameter-parameter penghematan energi serta mensimulasikannya pada sebuah bangunan perpustakaan Universitas Surabaya yang terdiri dari 6 lantai. Simulasi dilakukan menggunakan sofware EDGE. Hasil simulasi menunjukkan bahwa kombinasi 4 parameter penghematan energi dapat memberikan penghematan energi hingga 53%. Parameter tersebut adalah daylight photoelectric sensors for internal spaces (OFE29), radiant cooling and heating system (OFE16), higher thermal performance glass (OFE8), dan external shading devices (OFE4). Implementasi keempat parameter tersebut akan mengurangi emisi karbodiokasida 758 ton per tahun dengan payback period sekitar 2,2 tahun.Kata kunci: Efisiensi energi, energi pada bangunan, hemat energi, bangunan perpustakaan, simulasi energi 

scholarly journals Large-scale heat pumps in sustainable energy systems: System and project perspectives

2007 ◽  
Vol 11 (3) ◽  
pp. 143-152 ◽  
Author(s):  
Morten Blarke ◽  
Henrik Lund
Keyword(s):  
Low Temperature ◽  
Heat Source ◽  
Heat Production ◽  
Large Scale ◽  
Energy System ◽  
Heat Pumps ◽  
Production Costs ◽  
Coefficient Of Performance ◽  
Operational Mode ◽  
Temperature Heat

This paper shows that in support of its ability to improve the overall economic cost-effectiveness and flexibility of the Danish energy system, the financially feasible integration of large-scale heat pumps (HP) with existing combined heat and power (CHP) plants, is critically sensitive to the operational mode of the HP vis-?-vis the operational coefficient of performance, mainly given by the temperature level of the heat source. When using ground source for low-temperature heat source, heat production costs increases by about 10%, while partial use of condensed flue gasses for low-temperature heat source results in an 8% cost reduction. Furthermore, the analysis shows that when a large-scale HP is integrated with an existing CHP plant, the projected spot market situation in The Nordic Power Exchange (Nord Pool) towards 2025, which reflects a growing share of wind power and heat-supply constrained power generation electricity, further reduces the operational hours of the CHP unit over time, while increasing the operational hours of the HP unit. In result, an HP unit at half the heat production capacity as the CHP unit in combination with a heat-only boiler represents as a possibly financially feasible alternative to CHP operation, rather than a supplement to CHP unit operation. While such revised operational strategy would have impacts on policies to promote co-generation, these results indicate that the integration of large-scale HP may jeopardize efforts to promote co-generation. Policy instruments should be designed to promote the integration of HP with lower than half of the heating capacity of the CHP unit. Also it is found, that CHP-HP plant designs should allow for the utilization of heat recovered from the CHP unit?s flue gasses for both concurrent (CHP unit and HP unit) and independent operation (HP unit only). For independent operation, the recovered heat is required to be stored. .

Sustainable energy solutions for thermal load in buildings - Role of heat pumps, solar thermal, and hydrogen-based cogeneration systems

2021 ◽  
pp. 1-25
Author(s):  
Praveen Cheekatamarla ◽  
Vishaldeep Sharma ◽  
Bo Shen
Keyword(s):  
Energy Efficiency ◽  
Renewable Energy ◽  
Carbon Footprint ◽  
Energy Demand ◽  
Primary Energy ◽  
Heat Pumps ◽  
Total Carbon ◽  
Coefficient Of Performance ◽  
Renewable Energy Resources ◽  
The Impact

Abstract Economic and population growth is leading to increased energy demand across all sectors – buildings, transportation, and industry. Adoption of new energy consumers such as electric vehicles could further increase this growth. Sensible utilization of clean renewable energy resources is necessary to sustain this growth. Thermal needs in a building pose a significant challenge to the energy infrastructure. Supporting the current and future building thermal energy needs to offset the total electric demand while lowering the carbon footprint and enhancing the grid flexibility is presented in this study. Performance assessment of heat pumps, renewable energy, non-fossil fuel-based cogeneration systems, and their hybrid configurations was conducted. The impact of design configuration, coefficient of performance (COP), electric grid's primary energy efficiency on the key attributes of total carbon footprint, life cycle costs, operational energy savings, and site-specific primary energy efficiency are analyzed and discussed in detail.

scholarly journals Installation and Operation of a Solar Cooling and Heating System Incorporated with Air-Source Heat Pumps

Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 996 ◽  
Author(s):  
Li Huang ◽  
Rongyue Zheng ◽  
Udo Piontek
Keyword(s):  
Heating System ◽  
Cooling Capacity ◽  
Heat Pumps ◽  
Hot Water ◽  
Coefficient Of Performance ◽  
Energy Yield ◽  
Absorption Chiller ◽  
Annual Average ◽  
Water Storage Tank ◽  
Solar Cooling

A solar cooling and heating system incorporated with two air-source heat pumps was installed in Ningbo City, China and has been operating since 2018. It is composed of 40 evacuated tube modules with a total aperture area of 120 m2, a single-stage and LiBr–water-based absorption chiller with a cooling capacity of 35 kW, a cooling tower, a hot water storage tank, a buffer tank, and two air-source heat pumps, each with a rated cooling capacity of 23.8 kW and heating capacity of 33 kW as the auxiliary system. This paper presents the operational results and performance evaluation of the system during the summer cooling and winter heatingperiod, as well as on a typical summer day in 2018. It was found that the collector field yield and cooling energy yield increased by more than 40% when the solar cooling and heating system is incorporated with heat pumps. The annual average collector efficiency was 44% for cooling and 42% for heating, and the average coefficient of performance (COP) of the absorption chiller ranged between 0.68 and 0.76. The annual average solar fraction reached 56.6% for cooling and 62.5% for heating respectively. The yearly electricity savings accounted for 41.1% of the total electricity consumption for building cooling and heating.

Methodology for Optimizing the Heating Capacity of Heat-Source Equipments in Double-Energy Radiator Heating System

2012 ◽  
Vol 170-173 ◽  
pp. 2743-2746
Author(s):  
Feng Li ◽  
Zhe Tian ◽  
Qiang Fu ◽  
Qian Ru Li
Keyword(s):  
Heat Source ◽  
Operating Cost ◽  
Heating System ◽  
Heat Pumps ◽  
Heating Period ◽  
Heating Performance ◽  
Heating Capacity ◽  
Minimum Operating ◽  
Optimal Heating ◽  
Sewage Source

The double-energy heating system studied in this paper is consisted of centrifugal sewage-source heat pumps and gas boilers. As the grade and price of the two kinds of energy are different, the heating capacity of the heat-source equipments would have a directly impact on the energy consumption and operating cost of the system. In order to obtain the optimal heating capacity of the heat-source equipments, the calculation models on equipments utilized in this system are firstly established, and then different combination patterns of the heat-source equipments were analyzed on the basis of minimum operating cost, finally, the optimal heating capacity of the heat-source equipments and the heating performance factor (HPF) of the system in different outdoor temperatures were obtained, the results indicate the average HPF of the system in the heating period is 3.57. The method and results provide reference for scientific design of the double-energy heating system.

scholarly journals Study of Energy Efficiency Solutions for a Smart Water Heating System

2021 ◽  
Vol 16 (1) ◽  
pp. 43-49
Author(s):  
Najat Abdeljebbar ◽  
Abdelwahab Haddaoui
Keyword(s):  
Energy Efficiency ◽  
Renewable Energy ◽  
Water Consumption ◽  
Natural Water ◽  
Smart Cities ◽  
Heating System ◽  
Heat Pumps ◽  
Hot Water ◽  
Water Heating ◽  
Smart Water

The preservation of natural water and electricity resources is essential for the development of smart cities. Indeed, water and electricity are highly dependent and must be analyzed together to improve the energy efficiency. This article is about the study of the integration of renewable energy and smart solutions in a water heating system. The existing system uses mainly heat pumps to cover the most of the hot water needs. The purpose of this work is to explore possible solutions to optimize the electricity and the water consumption of the installation.

scholarly journals Recovery and Utilization of Low-Grade Waste Heat in the Oil-Refining Industry Using Heat Engines and Heat Pumps: An International Technoeconomic Comparison

Energies ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2560 ◽  
Author(s):  
Nikunj Gangar ◽  
Sandro Macchietto ◽  
Christos N. Markides
Keyword(s):  
Heat Source ◽  
Thermal Energy ◽  
Heat Pumps ◽  
Coefficient Of Performance ◽  
Oil Refining ◽  
Low Grade ◽  
Energy Prices ◽  
Steam Generation ◽  
Electricity Prices ◽  
Oil Refineries

We assess the technoeconomic feasibility of onsite electricity and steam generation from recovered low-grade thermal energy in oil refineries using organic Rankine cycle (ORC) engines and mechanical vapour compression (MVC) heat pumps in various countries. The efficiencies of 34 ORC and 20 MVC current commercial systems are regressed against modified theoretical models. The resulting theoretical relations predict the thermal efficiency of commercial ORC engines within 4–5% and the coefficient of performance (COP) of commercial MVC heat pumps within 10–15%, on average. Using these models, the economic viability of ORC engines and MVC heat pumps is then assessed for 19 refinery streams as a function of heat source and sink temperatures, and the available stream thermal energy, for gas and electricity prices in selected countries. Results show that: (i) conversion to electrical power with ORC engines is, in general, economically feasible for heat-source temperatures >70 °C, however with high sensitivity to energy prices; and (ii) steam generation in MVC heat pumps, even more sensitive to energy prices, is in some cases not economical under any conditions—it is only viable with high gas/low electricity prices, for large heat sources (>2 MW) and higher temperatures (>140 °C). In countries and conditions with positive economics, payback periods down to two years are found for both technologies.

Smart Heating System for Old Buildings - An Approach to the Decentralized Use of Renewable Energies

2016 ◽  
Vol 19 ◽  
pp. 20-26 ◽  
Author(s):  
Moritz Hein ◽  
Ralf Stöber ◽  
Gerhard Fischerauer ◽  
Johannes Bürner ◽  
Jörg Franke ◽  
...  
Keyword(s):  
Heat Pump ◽  
Electromagnetic Compatibility ◽  
Heating System ◽  
Renewable Energies ◽  
Hot Water ◽  
Coefficient Of Performance ◽  
Radiant Heating ◽  
Central Heating ◽  
Maximum Coefficient ◽  
Planar Carbon

The central heating units of buildings are typically replaced every 20 to 30 years. There exists a variety of solutions for fuel-and gas-based units, but it would be advantageous to be able to use renewable energies. This would become possible by the combination of planar carbon-fiber-based infrared (IR) radiant heating foils with a heat pump providing hot water. The main goal of our proposed overall control strategy is to increase the energy efficiency while maintaining the thermal comfort for the residents. We examined the electromagnetic compatibility of the heating foils and simulated the relative contributions of the amount of energy provided by the heat pump and by the heating foils to obtain a maximum coefficient of performance for the combined heating system.

scholarly journals Analysis of Different Strategies for Lowering the Operation Temperature in Existing District Heating Networks

Energies ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 321 ◽  
Author(s):  
Francesco Neirotti ◽  
Michel Noussan ◽  
Stefano Riverso ◽  
Giorgio Manganini
Keyword(s):  
Energy Efficiency ◽  
Power Plants ◽  
Waste Heat ◽  
Control Strategies ◽  
Renewable Energy Sources ◽  
District Heating ◽  
Heating System ◽  
Heat Pumps ◽  
Critical Parameters ◽  
District Heating System

District heating systems have an important role in increasing the efficiency of the heating and cooling sector, especially when coupled to combined heat and power plants. However, in the transition towards decarbonization, current systems show some challenges for the integration of Renewable Energy Sources and Waste Heat. In particular, a crucial aspect is represented by the operating temperatures of the network. This paper analyzes two different approaches for the decrease of operation temperatures of existing networks, which are often supplying old buildings with a low degree of insulation. A simulation model was applied to some case studies to evaluate how a low-temperature operation of an existing district heating system performs compared to the standard operation, by considering two different approaches: (1) a different control strategy involving nighttime operation to avoid the morning peak demand; and (2) the partial insulation of the buildings to decrease operation temperatures without the need of modifying the heating system of the users. Different temperatures were considered to evaluate a threshold based on the characteristics of the buildings supplied by the network. The results highlight an interesting potential for optimization of existing systems by tuning the control strategies and performing some energy efficiency operation. The network temperature can be decreased with a continuous operation of the system, or with energy efficiency intervention in buildings, and distributed heat pumps used as integration could provide significant advantages. Each solution has its own limitations and critical parameters, which are discussed in detail.

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