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Optimisation for interconnected energy hub system with combined ground source heat pump and borehole

Da HUO, Wei WEI, Simon Le BLOND

《能源前沿(英文)》 2018年 第12卷 第4期   页码 529-539 doi: 10.1007/s11708-018-0580-0

摘要: Ground source heat pumps (GSHP) give zero-carbon emission heating at a residential level. However, as the heat is discharged, the temperature of the ground drops, leading to a poorer efficiency. Borehole inter-seasonal thermal storage coupled with GSHP maintains the efficiency at a high level. To adequately utilize the high performance of combined GSHP and the borehole system to further increase system efficiency and reduce cost, such a combined heating system is incorporated into the interconnected multi-carrier system to support the heat load of a community. The borehole finite element (FE) model and an equivalent borehole transfer function are proposed and respectively applied to the optimisation to analyze the variation of GSHP performance over the entire optimisation time horizon of 24 h. The results validate the borehole transfer function, and the optimisation computation time is reduced by 17 times compared with the optimisation using the FE model.

关键词: borehole thermal storage     energy hub     ground source heat pumps (GSHP)     particle swarm optimisation    

R&D of the ground-coupled heat pump technology in China

Nairen DIAO, Ping CUI, Junhong LIU, Zhaohong FANG,

《能源前沿(英文)》 2010年 第4卷 第1期   页码 47-54 doi: 10.1007/s11708-009-0080-3

摘要: The ground-coupled heat pump (GCHP) systems have been identified as one of the best sustainable energy technologies for space heating and cooling in residential and commercial buildings. In this paper, research on and development of the GCHP technology in China are summarized. New models are presented for efficient thermal analysis of ground heat exchangers, of which one- and two-dimensional solid cylindrical source models and their analytical solutions are devised to deal with pile ground heat exchangers. Analytical solutions are also derived for vertical and inclined finite line source models as well as for a groundwater advection model. Explicit solutions of a quasi-three-dimensional model can be used to better evaluate the thermal resistance inside boreholes. Studies on hybrid GCHP systems and the thermal response test in China are also commented.

关键词: ground source heat pump     ground heat exchanger     HVAC     China    

Finite element modeling of thermo-active diaphragm walls

Yi RUI, Mei YIN

《结构与土木工程前沿(英文)》 2020年 第14卷 第3期   页码 646-663 doi: 10.1007/s11709-020-0584-9

摘要: There are two major challenges faced by modern society: energy security, and lowering carbon dioxide gas emissions. Thermo-active diaphragm walls have a large potential to remedy one of these problems, since they are a renewable energy technology that uses underground infrastructure as a heat exchange medium. However, extensive research is required to determine the effects of cyclic heating and cooling on their geotechnical and structural performance. In this paper, a series of detailed finite element analyses are carried out to capture the fully coupled thermo-hydro-mechanical response of the ground and diaphragm wall. It is demonstrated that the thermal operation of the diaphragm wall causes changes in soil temperature, thermal expansion/shrinkage of pore water, and total stress applied on the diaphragm wall. These, in turn, cause displacements of the diaphragm wall and variations of the bending moments. However, these effects on the performance of diaphragm wall are not significant. The thermally induced bending strain is mainly governed by the temperature differential and uneven thermal expansion/shrinkage across the wall.

关键词: thermo-active diaphragm wall     finite element analysis     thermo-hydro-mechanical coupling     ground source heat pump    

Evaluation of the performance of a centralized ground-water heat pump system in cold climate region

Shilei LU,Zhe CAI,Li ZHANG,Yiran LI

《能源前沿(英文)》 2014年 第8卷 第3期   页码 394-402 doi: 10.1007/s11708-014-0310-1

摘要: The aim of this study is to evaluate the performance of a centralized open-loop ground-water heat pump (GWHP) system for climate conditioning in Beijing with a cold climate in China. Thus, a long-time test was conducted on a running GWHP system for the heating season from December 2011 to March 2012. The analysis of the testing data indicates that the average heat-pump coefficient of performance (COP) and the COP of the system (COPs) are 4.27 and 2.59. The low value and large fluctuation in the range of COP are found to be caused by the heat transfixion in the aquifer and the bypass in the circulation loop. Therefore, some suggestions are proposed to improve the performance for GWHPs in the cold climate region in China.

关键词: ground-water heat pump (GWHP)     actual coefficient of performance     heat transfixion    

Effects of radiation and heat source/sink on unsteady MHD boundary layer flow and heat transfer over

Krishnendu Bhattacharyya

《化学科学与工程前沿(英文)》 2011年 第5卷 第3期   页码 376-384 doi: 10.1007/s11705-011-1121-0

摘要: In this paper, an investigation is made to study the effects of radiation and heat source/sink on the unsteady boundary layer flow and heat transfer past a shrinking sheet with suction/injection. The flow is permeated by an externally applied magnetic field normal to the plane of flow. The self-similar equations corresponding to the velocity and temperature fields are obtained, and then solved numerically by finite difference method using quasilinearization technique. The study reveals that the momentum boundary layer thickness increases with increasing unsteadiness and decreases with magnetic field. The thermal boundary layer thickness decreases with Prandtl number, radiation parameter and heat sink parameter, but it increases with heat source parameter. Moreover, increasing unsteadiness, magnetic field strength, radiation and heat sink strength boost the heat transfer.

关键词: MHD boundary layer     unsteady flow     heat transfer     thermal radiation     heat source/sink     shrinking sheet     suction/injection    

全球变暖使热泵更受欢迎

Chris Palmer

《工程(英文)》 2023年 第29卷 第10期   页码 2-4 doi: 10.1016/j.eng.2023.08.004

Performance analysis of an air-source heat pump using an immersed water condenser

Jie JI, Huide FU, Hanfeng HE, Gang PEI,

《能源前沿(英文)》 2010年 第4卷 第2期   页码 234-245 doi: 10.1007/s11708-009-0056-3

摘要: A distributed model of an air-source heat pump (ASHP) system and its experimental setup using an immersed water condenser were presented. Dynamic performance of the ASHP was then evaluated by both simulation and experiment. The results indicated that the system coefficient of performance (COP) decreased as the condenser temperature increased, ranging from 4.41 to 2.32 with the average COP equaling 3.29 during the experiment. Comparisons between simulation results and experimental measurements demonstrated that the model was able to yield satisfactory predictions. Furthermore, temperature profiles of the refrigerant in the evaporator and condenser were also given. This paper provides the theoretical and experimental background for ASHP system optimization and a valuable reference for a solar air-source heat pump water heater when the solar irradiation energy is insufficient on cloudy or rainy days.

关键词: air-source     heat pump     distributed model     immersed water condenser    

Optimization model analysis of centralized groundwater source heat pump system in heating season

Shilei LU,Yunfang QI,Zhe CAI,Yiran LI

《能源前沿(英文)》 2015年 第9卷 第3期   页码 343-361 doi: 10.1007/s11708-015-0372-8

摘要: The ground-water heat-pump system (GWHP) provides a high efficient way for heating and cooling while consuming a little electrical energy. Due to the lack of scientific guidance for operating control strategy, the coefficient of performance (COP) of the system and units are still very low. In this paper, the running strategy of GWHP was studied. First, the groundwater thermal transfer calculation under slow heat transfixion and transient heat transfixion was established by calculating the heat transfer simulation software Flow Heat and using correction factor. Next, heating parameters were calculated based on the building heat load and the terminal equipment characteristic equation. Then, the energy consumption calculation model for units and pumps were established, based on which the optimization method and constraints were established. Finally, a field test on a GWHP system in Beijing was conducted and the model was applied. The new system operation optimization idea for taking every part of the GWHP into account that put forward in this paper has an important guiding significance to the actual operation of underground water source heat pump.

关键词: optimization model     groundwater source heat pump system     theoretical analysis     example verification     heating season    

pumping analysis and experimental validation of beach well infiltration intake system in a seawater sourceheat pump system

Huan ZHANG,Shu LIU,Xuejing ZHENG,Gaofeng CHEN

《能源前沿(英文)》 2015年 第9卷 第3期   页码 335-342 doi: 10.1007/s11708-015-0365-7

摘要: Based on energy conservation equation and Darcy’s law, a model of beach well infiltration intake system applied in a seawater source heat pump system was established. The model consists of the seawater seepage and the heat transfer process. A porous medium model in a software named FLUENT was applied to simulate the seepage and the heat transfer process. This model was also validated by field experiment conducted on the seashore in Tianjin, China. The maximum relative error between simulation results and experimental results was 2.1% (less than 5%), which was acceptable in engineering application. The porosity and coefficient of thermal conductivity of the aquifer soil were determined to be 0.49 W/(m·K) and 1.46 W/(m·K), respectively in the simulation. In addition, the influencing factors of pumping water of beach well were also analyzed. The pumping water was found to increase when the distance between the beach well and the impervious boundary becomes longer, when the distance between the beach well and the supplying water source shortens, when the diameter of the beach well enlarges, and the drawdown enlarges.

关键词: water pumping analysis     experimental validation     infiltration intake system     seawater source heat pump    

A two-stage deep freezing chemisorption cycle driven by low-temperature heat source

Yuanyang HU, Liwei WANG, Lu XU, Ruzhu WANG, Jeremiah KIPLAGAT, Jian WANG

《能源前沿(英文)》 2011年 第5卷 第3期   页码 263-269 doi: 10.1007/s11708-011-0152-z

摘要: A two-stage chemisorption cycle suitable for deep-freezing application driven by low- temperature heat source was proposed. Through two-stage desorption processes, the two-stage cycle can break through the limitations of the heating temperature and ambient cooling temperature. The two-stage cycle based on CaCl /BaCl -NH working pair can utilize the heat source with a temperature of above 75°C, and simultaneously realize deep-freezing all the year round. Experimental results and performance prediction show that the adsorption quantity of calcium, theoretical coefficient of performance (COP) and optimized specific cooling power (SCP) of the CaCl /BaCl -NH chemisorption system are 0.489 kg/kg (salt), 0.24 and 120.7 W/kg, when the heating temperature, ambient cooling temperature, pseudo-evaporating temperature and mass ratio of reacting salt and expanded graphite are 85, 30, -20, and 4∶1, respectively.

关键词: adsorption     freezing     desorption     heat source    

基于平板热管的新型直膨式辐射可调节供暖末端 Article

吴一凡, 孙弘历, 段梦凡, 林波荣, 赵恒昕, 刘兆鸿

《工程(英文)》 2023年 第20卷 第1期   页码 192-207 doi: 10.1016/j.eng.2021.09.019

摘要:

建筑供暖电气化是实现碳中和目标的有效途径。作为一种清洁和可持续的电气化供暖技术,空气源热泵被广泛应用于缺乏集中供暖的地区。然而,现有末端形式存在难以同时实现间歇性和舒适性,且作为主要构件尚未较好地与空气源热泵匹配等问题。因此,本研究提出了一种与空气源热泵结合的新型辐射可调节供暖末端,以实现电气化节能减碳、间歇性和更好的热舒适性。针对辐射供暖末端目前存在三个主要问题,分别是峰值供热量受限、可调节性受限以及难以与空气源热泵结合,本文通过改进末端结构设计(改进A~E)提供了有效解决方案。研究结果表明,新末端能够将峰值供热量提升23.6%,并为使用者提供从10.1%到30.9%的可调辐射比。在此基础上,巧妙地借助平板热管减少了原有直膨式辐射供暖末端的制冷剂管路长度,进而改善了供暖末端的稳定性(利于回油)、间歇性(降低热惯性)和安全性(降低制冷剂泄漏风险)。此外,本文基于新末端提出了一种新的分阶段运行策略,可进一步提升末端的可调节性。本研究可以为电气化供暖助力建筑低碳提供一定参考。

关键词: 新型供暖末端     空气源热泵     结构优化设计     峰值供热能力     快速可调节性     房间温度分布    

Fault diagnosis of axial piston pumps with multi-sensor data and convolutional neural network

《机械工程前沿(英文)》 2022年 第17卷 第3期 doi: 10.1007/s11465-022-0692-4

摘要: Axial piston pumps have wide applications in hydraulic systems for power transmission. Their condition monitoring and fault diagnosis are essential in ensuring the safety and reliability of the entire hydraulic system. Vibration and discharge pressure signals are two common signals used for the fault diagnosis of axial piston pumps because of their sensitivity to pump health conditions. However, most of the previous fault diagnosis methods only used vibration or pressure signal, and literatures related to multi-sensor data fusion for the pump fault diagnosis are limited. This paper presents an end-to-end multi-sensor data fusion method for the fault diagnosis of axial piston pumps. The vibration and pressure signals under different pump health conditions are fused into RGB images and then recognized by a convolutional neural network. Experiments were performed on an axial piston pump to confirm the effectiveness of the proposed method. Results show that the proposed multi-sensor data fusion method greatly improves the fault diagnosis of axial piston pumps in terms of accuracy and robustness and has better diagnostic performance than other existing diagnosis methods.

关键词: axial piston pump     fault diagnosis     convolutional neural network     multi-sensor data fusion    

Mechanical responses of multi-layered ground due to shallow tunneling with arbitrary ground surface load

《结构与土木工程前沿(英文)》 2023年 第17卷 第5期   页码 745-762 doi: 10.1007/s11709-023-0935-4

摘要: An analytical model based on complex variable theory is proposed to investigate ground responses due to shallow tunneling in multi-layered ground with an arbitrary ground surface load. The ground layers are assumed to be linear-elastic with full-stick contact between them. To solve the proposed multi-boundary problem, a series of analytic functions is introduced to accurately express the stresses and displacements contributed by different boundaries. Based on the principle of linear-elastic superposition, the multi-boundary problem is converted into a superposition of multiple single-boundary problems. The conformal mappings of different boundaries are independent of each other, which allows the stress and displacement fields to be obtained by the sum of components from each boundary. The analytical results are validated based on numerical and in situ monitoring results. The present model is superior to the classical model for analyzing ground responses of shallow tunneling in multi-layered ground; thus, it can be used with assurance to estimate the ground movement and surface building safety of shallow tunnel constructions beneath surface buildings. Moreover, the solution for the ground stress distribution can be used to estimate the safety of a single-layer composite ground.

关键词: analytical model     mechanical response     multi-layered ground     shallow tunneling     ground surface load     complex variable solution    

变频驱动并联水泵变压变流量运行优化调度

李洪斌,张承慧,宋军

《中国工程科学》 2001年 第3卷 第9期   页码 52-57

摘要:

分析了变频驱动并联水泵变压变流量运行优化调度问题的常用建模方法,并比较了各种方法的优劣。 常用的方法是以水泵轴功率作为目标函数,以供水指标和高效区为约束条件。另一种方法是以满足扬程指标时 的实际流量与所需流量之差的二次方作为目标函数,以水泵的高效区作为约束条件。提出了一种新的建模方法, 模型物理意义与实际工况严格相符,具有较高的精度,满足了工程中对水泵切换频率尽量小的要求。仿真结果 表明该方法是有效的。

关键词: 优化调度     有约束非线性规划     水泵调速    

INTERACTIONS BETWEEN ABOVE AND BELOW GROUND PLANT STRUCTURES: MECHANISMS AND ECOSYSTEM SERVICES

《农业科学与工程前沿(英文)》 2022年 第9卷 第2期   页码 197-213 doi: 10.15302/J-FASE-2021433

摘要:

Interactions between above and below ground parts of plants can be considered under the (overlapping) categories of energy, material and information. Solar energy powers photosynthesis and transpiration by above ground structures, and drives most water uptake through roots and supplies energy as organic matter to below ground parts, including diazotrophic symbionts and mycorrhizas. Material transfer occurs as water and dissolved soil-derived elements transport up the xylem, and a small fraction of water moving up the xylem with dissolved organic carbon and other solutes down the phloem. The cytosolic nature of sieve tubes accounts for at least some of the cycling of K, Mg and P down the phloem. NO3 assimilation of above ground parts requires organic N transport down phloem with, in some cases, organic anions related to shoot acid-base regulation. Long-distance information transfer is related development, biotic and abiotic damage, and above and below ground resource excess and limitation. Information transfer can involve hydraulic, electrical and chemical signaling, with their varying speeds of transmission and information content. Interaction of above and below ground plant parts is an important component of the ecosystem service of storing atmospheric CO2 as organic C in soil, a process that has decreased since the origin of agriculture.

关键词: aerenchyma / carbon accumulation / hormones / phloem / xylem    

标题 作者 时间 类型 操作

Optimisation for interconnected energy hub system with combined ground source heat pump and borehole

Da HUO, Wei WEI, Simon Le BLOND

期刊论文

R&D of the ground-coupled heat pump technology in China

Nairen DIAO, Ping CUI, Junhong LIU, Zhaohong FANG,

期刊论文

Finite element modeling of thermo-active diaphragm walls

Yi RUI, Mei YIN

期刊论文

Evaluation of the performance of a centralized ground-water heat pump system in cold climate region

Shilei LU,Zhe CAI,Li ZHANG,Yiran LI

期刊论文

Effects of radiation and heat source/sink on unsteady MHD boundary layer flow and heat transfer over

Krishnendu Bhattacharyya

期刊论文

全球变暖使热泵更受欢迎

Chris Palmer

期刊论文

Performance analysis of an air-source heat pump using an immersed water condenser

Jie JI, Huide FU, Hanfeng HE, Gang PEI,

期刊论文

Optimization model analysis of centralized groundwater source heat pump system in heating season

Shilei LU,Yunfang QI,Zhe CAI,Yiran LI

期刊论文

pumping analysis and experimental validation of beach well infiltration intake system in a seawater sourceheat pump system

Huan ZHANG,Shu LIU,Xuejing ZHENG,Gaofeng CHEN

期刊论文

A two-stage deep freezing chemisorption cycle driven by low-temperature heat source

Yuanyang HU, Liwei WANG, Lu XU, Ruzhu WANG, Jeremiah KIPLAGAT, Jian WANG

期刊论文

基于平板热管的新型直膨式辐射可调节供暖末端

吴一凡, 孙弘历, 段梦凡, 林波荣, 赵恒昕, 刘兆鸿

期刊论文

Fault diagnosis of axial piston pumps with multi-sensor data and convolutional neural network

期刊论文

Mechanical responses of multi-layered ground due to shallow tunneling with arbitrary ground surface load

期刊论文

变频驱动并联水泵变压变流量运行优化调度

李洪斌,张承慧,宋军

期刊论文

INTERACTIONS BETWEEN ABOVE AND BELOW GROUND PLANT STRUCTURES: MECHANISMS AND ECOSYSTEM SERVICES

期刊论文