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Lin Fu - One of the best experts on this subject based on the ideXlab platform.

  • new configurations of District Heating System based on natural gas and deep geothermal energy for higher energy efficiency in northern china
    Applied Thermal Engineering, 2019
    Co-Authors: Xinyu Zhao, Xu Chen, Lin Fu
    Abstract:

    Abstract To decrease irreversible loss and reduce natural gas consumption of conventional District Heating Systems based on natural gas fired boilers, new configurations of the District Heating System based on natural gas and deep geothermal energy are proposed and analyzed from the perspective of thermodynamics and financial benefit. The results show that the proposed District Heating System based on natural gas and deep geothermal energy with absorption heat exchangers and a gas-fired absorption heat pump (DH-AHE-DAHP) not only has higher thermodynamic performance, but also enables us to gain better financial benefit, and its configuration is optimal. Compared with conventional District Heating Systems based on natural gas, the DH-AHE-DAHP could increase product exergy efficiency by about 12%, reduce natural gas consumption by about 54% and Heating cost by about 25%, and its cost-effective heat transmission distance of the primary Heating network could approach about 28 km, which contributes to efficient exploiting deep geothermal fields far away from urban Districts for space Heating.

  • new low temperature industrial waste heat District Heating System based on natural gas fired boilers with absorption heat exchangers
    Applied Thermal Engineering, 2017
    Co-Authors: Lijiao Cheng, Lin Fu
    Abstract:

    Abstract To efficiently recover low temperature industrial waste heat, a new low temperature industrial waste heat District Heating System based on natural gas fired boilers with absorption heat exchangers was proposed, and also analyzed from the perspective of thermodynamics and economics. In Heating substations, absorption heat exchangers are used to greatly decrease the return water temperature of the primary Heating network. The lower temperature return water helps to efficiently recover waste heat in Heating station and greatly increase economic heat transmission distance. Annual primary energy efficiency and product exergy efficiency of the new District Heating System are 215.0% and 42.5% respectively. When waste heat price and heat transmission heat distance are 25 ¥/GJ and 60 km respectively, its Heating cost and investment recovery period are 6 ¥/GJ and 0.7 years respectively lower than that of current District Heating Systems based on natural gas fired boilers. Characterized by better thermodynamic performance and economic benefit, the new District Heating System would be promising for low-temperature industrial waste heat recovery.

  • new waste heat District Heating System with combined heat and power based on absorption heat exchange cycle in china
    Applied Thermal Engineering, 2012
    Co-Authors: Lin Fu, Shigang Zhang
    Abstract:

    Abstract A new waste heat District Heating System with combined heat and power based on absorption heat exchange cycle (DHAC) was developed to increase the Heating capacity of combined heat and power (CHP) through waste heat recovery, and enhance heat transmission capacity of the existing primary side District Heating network through decreasing return water temperature by new type absorption heat exchanger (AHE). The DHAC System and a conventional District Heating System based on CHP (CDH) were analyzed in terms of both thermodynamics and economics. Compared to CDH, the DHAC increased Heating capacity by 31% and increased heat transmission capacity of the existing primary side District Heating network by 75%. The results showed that the exergetic efficiency of DHAC was 10.41% higher and the product exergy monetary cost was 36.6¥/GJ less than a CHD. DHAC is an effective way to increase thermal utilization factor of CHP, and to reduce District Heating cost.

  • Exergoeconomic Analysis of New High-Temperature District Heating System Based on Absorption Heat Pump Technology in Combined Heat and Power
    Volume 5: Energy Systems Analysis Thermodynamics and Sustainability; NanoEngineering for Energy; Engineering to Address Climate Change Parts A and B, 2010
    Co-Authors: Lin Fu, Shigang Zhang
    Abstract:

    Space Heating area of District Heating System of combined heat and power (CHP) accounts for approximately one third of total space Heating area in Chinese northern cities. In the extraction condensing turbine combined heat and power System based on District Heating network, there are a large number of low-grade waste heat in the condenser, and exergy loss in the steam-water heat exchanger and water-water heat exchanger. Based on absorption heat pump technology, a new high-temperature District Heating technology (DHSAHP) was presented to improve the current District Heating System of CHP. Absorption heat pumps are used to recycle low-temperature waste heat in condenser. Absorption heat pump type heat exchanger is used to reduce temperature of return water in primary heat network, and decrease irreversible loss. Where, DHSAHP was analyzed by thermodynamics and economics method, and evaluated by exergetic efficiency, exergetic output cost, exergetic cost difference and exergoeconomic factor. Compared with current District Heating System of CHP, DHSAHP can decrease about 31.3% steam consumption, increase about 75% transmission and distribution capacity of the primary Heating network. The evaluation results show that the exergetic efficiency of new District Heating System of CHP based on the absorption cycle technology is higher 10.41% than that of current District Heating System of CHP, whereas its exergetic cost is lower 36.6¥/GJ than that of the conventional District Heating System. With the increase of annual Heating time, economy efficiency of new District Heating System of CHP becomes better. The DHSAHP has higher energy utilization efficiency and better economic benefits and provides a kind of better technological method to solve the main problems of cuurent District Heating with CHP in China.Copyright © 2010 by ASME

Martin Kumar Patel - One of the best experts on this subject based on the ideXlab platform.

  • simulation method for assessing hourly energy flows in District Heating System with seasonal thermal energy storage
    Renewable Energy, 2020
    Co-Authors: Kapil Narula, Fleury De Oliveira Filho, Willy Villasmil, Martin Kumar Patel
    Abstract:

    Abstract Domestic hot water and space Heating demand in buildings contribute a high share of final energy demand. This demand is often met by fossil fuels, leading to large greenhouse gas emissions. Although renewable energy can be used for Heating, there is time discordance between heat supply and heat demand. Seasonal thermal energy storage is a viable solution to overcome this mismatch. This paper presents a simulation method and a simple tool to assess the feasibility of integrating a seasonal thermal energy storage equipped with heat exchangers and/or heat pumps in a District Heating System. The developed method and tool are generic and allow the simulation of hourly energy flows using energy balances and predefined conditions. In order to validate the proposed method, the result of the simulated energy flows from two selected Systems, Friedrichshafen and Marstal, are compared with monitored values reported in literature. The comparison shows that while simulation of monthly energy flows depends on the accuracy of inputs to the tool, annual energy flows can be closely replicated. Hence, the method can be considered as validated. This simulation tool and method can be used to assess energy flows in a District Heating System in future.

Lin Duanmu - One of the best experts on this subject based on the ideXlab platform.

  • energy saving factors affecting analysis on District Heating System with distributed variable frequency speed pumps
    Applied Thermal Engineering, 2017
    Co-Authors: Xianjie Sheng, Lin Duanmu
    Abstract:

    Abstract The distributed variable-frequency speed pump (DVFSP) District Heating System is not only to set circulating pump in the heat source, but also to set booster pumps in the Heating pipeline network. All pumps adopt frequency conversion control. Compared with the traditional centralized power heat supply System, the distributed variable-frequency speed pump District Heating System has more advantages in solving the hydraulic imbalances and improving the energy-saving rate of the Heating System. In China the application of distributed variable speed pumps in the District Heating (DH) network has been considered as a technology improvement that has a potential of saving energy, compared to the conventional central circulating pump (CCCP) DH System. In order to analyze the factors affecting energy-saving rates and pipe network balance mathematical analytical method is used in this paper. In the conclusion, how to further improve the energy saving rate will be put forward together with the improvements for hydraulic stability balance as a reference of optimized engineering design.

  • energy efficiency enhancement potential of the heat pump unit in a seawater source heat pump District Heating System
    Procedia Engineering, 2016
    Co-Authors: Shu Hiawen, Wang Tingyu, Ren Zhiyong, Yu Haiyang, Lin Duanmu
    Abstract:

    Abstract Seawater source heat pump District Heating System is a renewable energy utilization System as it can utilize the sensible heat energy contained in the seawater. The energy efficiency of the System is always the main concern for the System researchers. So a field measurement with an emphasis on the energy efficiency of an actual seawater source heat pump District Heating System was conducted, and the energy efficiency enhancement potential of the heat pump unit was analyzed and evaluated. The measurement showed that the heat pump units consumed the largest part of energy consumption of the whole System, and the coefficient of Heating performance (COP) of the seawater source heat pump units was quite low especially during the coldest measurement period which was only 2.43. In the light of the concept of Thermodynamic Perfectibility, the energy efficiency enhancement potential of the heat pump unit was carefully analyzed and calculated. And the results showed that there is about an average of 24.2% energy efficiency enhancement potential of the heat pump units in this project.

  • field measurement and energy efficiency enhancement potential of a seawater source heat pump District Heating System
    Energy and Buildings, 2015
    Co-Authors: Lin Duanmu, Haiyang Yu
    Abstract:

    Abstract As a renewable energy utilization System, seawater source heat pump District Heating System can eliminate the local air pollution compared with the direct combustion of fuel in the conventional boiler house District Heating System in northern cold climate area. A field measurement with an emphasis on the energy efficiency of an actual seawater source heat pump District Heating System was conducted and analyzed. The field measurement showed that the heat pump units consumed the largest part of energy consumption of the whole System (as high as 78.9% in the project). However, the coefficient of Heating performance (COP) of the seawater source heat pump unit was as low as 2.43. Then the energy efficiency enhancement potential of the heat pump unit was carefully analyzed and calculated in the light of the index of Thermodynamic Perfectibility for the heat pump unit. And the results showed that there is about an average of 24.2% energy efficiency enhancement potential of the heat pump units in the project. In the end, a verification case study indicated that the COP of the heat pump units in the project will increase 34.6% if they are substituted by the ones made by another manufacturer.

  • Factor Analysis for Evaluating Energy-Saving Potential of Electric-Driven Seawater Source Heat Pump District Heating System Over Boiler House District Heating System
    Lecture Notes in Electrical Engineering, 2013
    Co-Authors: Haiwen Shu, Hongbin Wang, Lin Duanmu
    Abstract:

    Although the seawater source heat pump District Heating System is often regarded as a renewable energy utilization System, it cannot be guaranteed to obtain the energy-saving effect. The authors provided an energy-saving judgement method for the electric-driven seawater source heat pump District Heating System over the conventional boiler house District Heating System in former research. However, many factors will influence the energy efficiency of the System. In order to enhance its energy efficiency and make the best use of the System, detail analysis of those factors is conducted in the paper. First, an energy-saving potential evaluation model is derived for the System with part-time operation mode. Then all the factors influencing the energy efficiency of the System are ascertained and analyzed. These factors include the electricity generation efficiency, energy performance of seawater source heat pump units, the seawater temperature, the energy consumption of the seawater pump, the local outdoor air temperature, and the Heating District radius. The research results are expected to provide clear directions for the seawater source heat pump System to raise its energy efficiency.

Robert Sekret - One of the best experts on this subject based on the ideXlab platform.

  • buildings and a District Heating network as thermal energy storages in the District Heating System
    Energy and Buildings, 2018
    Co-Authors: Michal Turski, Robert Sekret
    Abstract:

    Abstract The aim of this article was to determine the energetic effect of use buildings and a District Heating network as thermal energy storages to compensate the reduced heat output of the District Heating System. Moreover, another so far underestimated values were analyzed, like the effect of the incidence of external temperature and duration of episodes with the lowest external temperatures on the heat output of the District Heating System based on 63 Heating seasons. Obtained results were presented for the reference District Heating System in Poland. According to the results, an average daily external temperature below −15 °C occurred once per Heating season and temperatures below −20 °C occurred only once in four Heating seasons. The analysis shows that a temperature of −18 °C can be adopted as the reference to determine the expected heat output in the DHS. On this basis the heat output can be reduced for central Heating by 1%. The energetic effect of use buildings and a District Heating network as thermal energy storages to compensate the reduced heat output of the District Heating System was 16.2 MW. The achieved equivalent heat output was 93.2 MW. Considering all solutions, the heat output can be reduced for central Heating by 14.8%.

Kapil Narula - One of the best experts on this subject based on the ideXlab platform.

  • simulation method for assessing hourly energy flows in District Heating System with seasonal thermal energy storage
    Renewable Energy, 2020
    Co-Authors: Kapil Narula, Fleury De Oliveira Filho, Willy Villasmil, Martin Kumar Patel
    Abstract:

    Abstract Domestic hot water and space Heating demand in buildings contribute a high share of final energy demand. This demand is often met by fossil fuels, leading to large greenhouse gas emissions. Although renewable energy can be used for Heating, there is time discordance between heat supply and heat demand. Seasonal thermal energy storage is a viable solution to overcome this mismatch. This paper presents a simulation method and a simple tool to assess the feasibility of integrating a seasonal thermal energy storage equipped with heat exchangers and/or heat pumps in a District Heating System. The developed method and tool are generic and allow the simulation of hourly energy flows using energy balances and predefined conditions. In order to validate the proposed method, the result of the simulated energy flows from two selected Systems, Friedrichshafen and Marstal, are compared with monitored values reported in literature. The comparison shows that while simulation of monthly energy flows depends on the accuracy of inputs to the tool, annual energy flows can be closely replicated. Hence, the method can be considered as validated. This simulation tool and method can be used to assess energy flows in a District Heating System in future.