A combined system utilizing LNG and low-temperature waste heat energy

2016 ◽  
Vol 101 ◽  
pp. 525-536 ◽  
Author(s):  
Mo-Geng Zhang ◽  
Liang-Ju Zhao ◽  
Chao Liu ◽  
Yi-Lin Cai ◽  
Xi-Min Xie
Keyword(s):  
Low Temperature ◽  
Waste Heat ◽  
Heat Energy ◽  
Combined System

scholarly journals Comparative analysis of possibilities for raising the efficiency in thermal power plant by utilisation of waste heat energy

2016 ◽  
Vol 20 (6) ◽  
pp. 2171-2181
Author(s):  
Vladimir Mijakovski ◽  
Vangelce Mitrevski ◽  
Tale Geramitcioski
Keyword(s):  
Power Plant ◽  
Low Temperature ◽  
Thermal Power Plant ◽  
Waste Heat ◽  
Thermal Power ◽  
Heat Energy ◽  
Economic Feasibility ◽  
Energy Utilization ◽  
Temperature Heat ◽  
Basic Power

The possibility to use flue gases waste heat for increasing the efficiency of thermal power plant (TPP) explained in this work refers to lignite fired TPP-Bitola in Macedonia (3x233 MW installed electric capacity). Possibility to utilize low-temperature heat energy at the plant?s cold end is also considered in the analysis. Specific fuel consumption is used as an analysis and comparison parameter. Its reduction, compared to the basic power unit ranges between 0.4% and 3.4%. An analysis presenting economic feasibility of the low-temperature heat energy utilization concept for two different refrigerants used in the heat pump is also presented.

Development of an All-in-One Type Adsorption Heat Pump for Heating Application

2011 ◽  
Vol 9 (1) ◽  
Author(s):  
Lihua Dong ◽  
Hongyu Huang ◽  
Noriyuki Kobayashi
Keyword(s):  
Heat Exchanger ◽  
Low Temperature ◽  
Heat Pump ◽  
Waste Heat ◽  
Heat Energy ◽  
Adsorption Heat ◽  
Pump System ◽  
Adsorption Heat Pump ◽  
Temperature Heat ◽  
High Output

The present research of adsorption heat pump system for heating application mainly focuses on its miniaturization and high output. When the adsorption heat pump is downsized the heat energy is insufficient to meet heating application. In addition, a large amount of low-temperature heat energy in industry has not been utilized but discharged into the atmosphere as waste heat. To improve energy efficiency and reduce carbon dioxide emission, it is important to effectively utilize the low-temperature heat source which is usually discarded as waste heat. In order to solve the problem between the miniaturization and the high output, a miniature all-in-one type adsorption heat pump which can effectively utilize waste heat is designed. In this design, a heat exchanger coated with adsorption material is used as an adsorber or desorber, and another heat exchanger is used as an evaporator or condenser. A seal unit is formed by assembling two heat exchangers into a vacuum tight container and is connected to the surroundings only by hydraulic piping. Moreover, the adsorbent is a functional adsorbent material-zeolite (AQSOA FAM-Z02, Mitsubishi Plastics) which can be regenerated by utilizing the low-temperature heat energy between 75 and 100°C. In this paper the design and experimental performance of this all-in-one type adsorption heat pump are described.

scholarly journals Thermodynamic Analysis of a Combined Single Effect Vapour Absorption System and tc-CO2 Compression Refrigeration System

2021 ◽  
Vol 2 (2) ◽  
pp. 87-98
Author(s):  
Abhishek Verma ◽  
S. C. Kaushik ◽  
S. K. Tyagi
Keyword(s):  
Low Temperature ◽  
Waste Heat ◽  
Electricity Consumption ◽  
Combined Cycle ◽  
Refrigeration System ◽  
Absorption System ◽  
Combined System ◽  
Single Effect ◽  
Exergetic Analysis ◽  
Low Temperature Refrigeration

Transcritical CO2 refrigeration system is coupled with the single effect vapour absorption with LiBr-water as a working pair having an objective to enhance the performance of low temperature transcritical refrigeration system while using natural working pair and to reduce the electricity consumption to produce low temperature refrigeration. The high grade waste heat rejected in the gas cooler of tc-CO2 compression refrigeration system (TCRS) is utilized to run the single effect vapour absorption system (SEVAR) to enhance the energy efficiency of the system. The gas cooler in the transcritical CO2 system is having heat energy at high temperature and pressure, which is utilized to run the vapour absorption system, while the other refrigerant heat exchanger provides subcooling to further enhance the performance. The combined cycle can provide refrigeration temperature at different levels, to use it for different applications. Energetic and exergetic analysis have been done to analyze the combined system to compute the performance parameters and the irreversibilities occurring in different components to further increase the performance. The combined system is optimized for various heat rejection and refrigeration temperatures. The COP of the combined system has been enhanced by to 24.88% while the enhancement in exergetic efficiency (ηex) is observed as 10.14% respectively over tradition transcritical CO2 compression refrigeration system, with -10°C as an evaporation (TCRS cooling) temperature and exit temperature of gas cooler T4 being 40°C. Doi: 10.28991/HIJ-2021-02-02-02 Full Text: PDF

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.

scholarly journals RELaTED Project: New Developments on Ultra-Low Temperature District Heating Networks

Proceedings ◽  
2020 ◽  
Vol 65 (1) ◽  
pp. 25
Author(s):  
Antonio Garrido Marijuan ◽  
Roberto Garay ◽  
Mikel Lumbreras ◽  
Víctor Sánchez ◽  
Olga Macias ◽  
...  
Keyword(s):  
Low Temperature ◽  
High Performance ◽  
Waste Heat ◽  
District Heating ◽  
Hot Water ◽  
Thermal Systems ◽  
Heating Source ◽  
Wide Range ◽  
Thermal Sources ◽  
Heating Networks

District heating networks deliver around 13% of the heating energy in the EU, being considered as a key element of the progressive decarbonization of Europe. The H2020 REnewable Low TEmperature District project (RELaTED) seeks to contribute to the energy decarbonization of these infrastructures through the development and demonstration of the following concepts: reduction in network temperature down to 50 °C, integration of renewable energies and waste heat sources with a novel substation concept, and improvement on building-integrated solar thermal systems. The coupling of renewable thermal sources with ultra-low temperature district heating (DH) allows for a bidirectional energy flow, using the DH as both thermal storage in periods of production surplus and a back-up heating source during consumption peaks. The ultra-low temperature enables the integration of a wide range of energy sources such as waste heat from industry. Furthermore, RELaTED also develops concepts concerning district heating-connected reversible heat pump systems that allow to reach adequate thermal levels for domestic hot water as well as the use of the network for district cooling with high performance. These developments will be demonstrated in four locations: Estonia, Serbia, Denmark, and Spain.

scholarly journals Design of a Database of Case Studies and Technologies to Increase the Diffusion of Low-Temperature Waste Heat Recovery in the Industrial Sector

2021 ◽  
Vol 13 (9) ◽  
pp. 5223
Author(s):  
Miriam Benedetti ◽  
Daniele Dadi ◽  
Lorena Giordano ◽  
Vito Introna ◽  
Pasquale Eduardo Lapenna ◽  
...  
Keyword(s):  
Low Temperature ◽  
Case Studies ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Industrial Sector ◽  
Implementation Rate ◽  
Depth Analysis ◽  
Technology Market

The recovery of waste heat is a fundamental means of achieving the ambitious medium- and long-term targets set by European and international directives. Despite the large availability of waste heat, especially at low temperatures (<250 °C), the implementation rate of heat recovery interventions is still low, mainly due to non-technical barriers. To overcome this limitation, this work aims to develop two distinct databases containing waste heat recovery case studies and technologies as a novel tool to enhance knowledge transfer in the industrial sector. Through an in-depth analysis of the scientific literature, the two databases’ structures were developed, defining fields and information to collect, and then a preliminary population was performed. Both databases were validated by interacting with companies which operate in the heat recovery technology market and which are possible users of the tools. Those proposed are the first example in the literature of databases completely focused on low-temperature waste heat recovery in the industrial sector and able to provide detailed information on heat exchange and the technologies used. The tools proposed are two key elements in supporting companies in all the phases of a heat recovery intervention: from identifying waste heat to choosing the best technology to be adopted.

scholarly journals Rolling membrane powered by low-temperature steam as a new approach to generate mechanical energy

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Chongshan Yin ◽  
Qicheng Liu ◽  
Qing Liu
Keyword(s):  
Water Vapor ◽  
Low Temperature ◽  
Combustion Engine ◽  
Mechanical Energy ◽  
Heat Energy ◽  
Steam Engine ◽  
Low Grade ◽  
Human Society ◽  
New Approach ◽  
Low Grade Heat

Abstract How to convert heat energy into other forms of usable energy more efficiently is always crucial for our human society. In traditional heat engines, such as the steam engine and the internal combustion engine, high-grade heat energy can be easily converted into mechanical energy, while a large amount of low-grade heat energy is usually wasted owing to its disadvantage in the temperature level. In this work, for the first time, the generation of mechanical energy from both high- and low-temperature steam is implemented by a hydrophilic polymer membrane. When exposed to water vapor with a temperature ranging from 50 to 100 °C, the membrane repeats rolling from one side to another. In nature, this continuously rolling of membrane is powered by the steam, like a miniaturized “steam engine”. The differential concentration of water vapor (steam) on the two sides of the membrane generates the asymmetric swelling, the curve, and the rolling of the membrane. In particular, results suggest that this membrane based “steam engine” can be powered by the steam with a relatively very low temperature of 50 °C, which indicates a new approach to make use of both the high- and low-temperature heat energy.

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