Study on an energy-saving process for separation ethylene elycol mixture through heat-pump, heat-integration and ORC driven by waste-heat

Abstract Heat integration with absorption heat pumps requires investigation of many types of plant designs. In this article, it is concluded that in many cases high temperature absorption systems for heat recovery are more economically feasible than absorption systems for cooling purposes. The conclusion is based on a project where the scope was to investigate technical and economical possibilities for heat integration of an absorption heat pump in a milk powder plant. The first idea behind the project was to use the waste heat from the rejected air to drive an absorption cooling system to reduce the electricity consumption for cooling proposes. The model of the plant was based on simulations as a background for a time averaged COP model. It was concluded that an absorption system for generating low temperature steam is more feasible.

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COMPARISON OF ENERGY SAVING METHODS FOR DISTILLATION OF LIQUID MIXTURES

IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENIY KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA ◽

10.6060/ivkkt.20216401.6141 ◽

2020 ◽

Vol 64 (1) ◽

pp. 85-92

Author(s):

Mikhail K. Zakharov ◽

Yuri A. Pisarenko ◽

Oksana I. Sycheva

Keyword(s):

Energy Saving ◽

Internal Energy ◽

Heat Pump ◽

Distillation Column ◽

Scientific Literature ◽

Heat Removal ◽

Heat Consumption ◽

Heat Integration ◽

Additional Increase ◽

Internal Energy Saving

The analysis and review of the scientific literature on methods and approaches to energy saving in distillation, as one of the most energy-intensive processes for the separation of binary and multicomponent mixtures was carried out. Directions of the scientific literature are highlighted, showing the relevance of the thermodynamic method assessment of separation processes. A comparative analysis of various methods of energy conservation in the separation of liquid binary mixtures by the distillation method is performed (a binary mixture of benzene-toluene was chosen as an example). A conventional distillation column as well as a column with a heat pump and a column with heat integration were considered. As a result of the calculation experiment for each option performed using the Aspen Plus software package the optimal column parameters were determined - the total number of stages and the position of feed stage. The heat consumption in the column boiler was taken as the objective function. It is also shown that with the same characteristics of the columns, the best way to organize the process for separating the selected mixture is to compress the steam stream from rectifying profile of the column with its subsequent use in the boiler of the stripping profile according to the principle of a heat pump. It was established by a calculation experiment that heat integration by compressing steam from rectifying profile of the column and supplying it to the stripping profile gives significantly less energy saving. The calculation of internal energy saving by distillation column was carried out and it was shown that the distributed heat removal from the plates of the rectifying profile of the column and the supply of this heat to the stripping profile plates reduces internal energy saving and leads to an additional increase in heat consumption in the boiler.

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A Smart Community Waste Heat Recovery System Based on Air Source-Sewage Source Compound Heat Pump

International Journal of Heat and Technology ◽

10.18280/ijht.390220 ◽

2021 ◽

Vol 39 ◽

pp. 503-511

Author(s):

Yonggao Cheng ◽

Yanqing Wu ◽

Siran Bai

Keyword(s):

Energy Saving ◽

Heat Pump ◽

Heat Recovery ◽

Waste Heat Recovery ◽

Waste Heat ◽

Waste Heat Recovery System ◽

Recovery System ◽

Heat Recovery System ◽

Smart Community ◽

Sewage Source

Compared with the traditional hot water production methods, heat pump systems have the unique advantages of high efficiency, energy saving, and eco-friendly, so they have a very good promotion and application prospect. The sewage source heat pump systems can recover the waste heat of high-temperature sewage produced in residential communities, for this reason, this study integrated the proven air source heat pump technology with the sewage source heat pump technology and conducted a research on the smart community waste heat recovery system based on the air-source/sewage-source Compound Heat Pump system (CHP system). In the paper, the design steps and equipment selection flow of the proposed system were given, the waste heat utilization rate of the proposed system was calculated, and the obtained experimental results verified the energy-saving effect of the proposed system, which had provided a reference for the application of the compound heat pumps in other occasions.

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Economic Analysis of Heat Pump Recovery System for Circulating Water Waste Heat in Power Plant

E3S Web of Conferences ◽

10.1051/e3sconf/202125602011 ◽

2021 ◽

Vol 256 ◽

pp. 02011

Author(s):

Ze Wang ◽

Honghong Shen ◽

Qunyin Gu ◽

Daoyuan Wen ◽

Gang Liu ◽

...

Keyword(s):

Power Plant ◽

Energy Saving ◽

Heat Pump ◽

Waste Heat ◽

Heat Pumps ◽

Water Saving ◽

Absorption Heat Pump ◽

Circulating Water ◽

Cold Source ◽

Heat Pump Unit

The use of heat pump technology to recover the waste heat of circulating water from the power plant instead of steam extraction for heating can not only improve the thermal efficiency of the unit and reduce the loss of cold source, but also has great advantages in energy saving. This paper uses absorption and compression heat pumps to recover the waste heat of circulating water in the power plant to study its energy-saving benefits. Under the same heating load, the economics of the two heat pumps are calculated and analyzed. The results show that the energy-saving benefits of absorption heat pump units are far greater than compression units. But in terms of water saving, the water saving capacity of the compression heat pump unit is higher than that of the absorption heat pump.

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Application of Double-Used Absorption Heat Pump in Power Plants

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.542-543.70 ◽

2012 ◽

Vol 542-543 ◽

pp. 70-73 ◽

Cited By ~ 1

Author(s):

Xin Hui Cao ◽

Guang Zhang ◽

Xi Lun Wang ◽

Yu Ning Zhang

Keyword(s):

Power Plant ◽

Energy Saving ◽

Heat Pump ◽

Power Plants ◽

Waste Heat ◽

Water Saving ◽

Energy Utilization ◽

Absorption Heat Pump ◽

Quantitative Calculation ◽

Steam Extraction

Absorption heat pump (AHP) heating in power plants in winter is an effective way to recover waste heat and make full use of energy. In this paper, quantitative calculation is taken to analyze the energy saving and economy efficiency of AHP heating in a power plant. The rate of energy utilization ηtp, the coal and water saving amount and the increased income of AHP heating are calculated. Results show AHP heating in power plants is superior to steam extraction heating both in energy saving and economy.

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Energy Saving Analysis of Circulating Water Waste Heat Recovery from Water Source Heat Pump

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/295/5/052016 ◽

2019 ◽

Vol 295 ◽

pp. 052016

Author(s):

Chuang Ma ◽

Jianxing Ren ◽

Fangqin Li ◽

Xin Hou ◽

Haijun Feng ◽

...

Keyword(s):

Energy Saving ◽

Heat Pump ◽

Heat Recovery ◽

Waste Heat Recovery ◽

Waste Heat ◽

Water Source ◽

Circulating Water ◽

Water Waste

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Simulation and Economic Research of Circulating Cooling Water Waste Heat and Water Resource Recovery System

Energies ◽

10.3390/en14092496 ◽

2021 ◽

Vol 14 (9) ◽

pp. 2496

Author(s):

Li Yang ◽

Yunfeng Ren ◽

Zhihua Wang ◽

Zhouming Hang ◽

Yunxia Luo

Keyword(s):

Energy Saving ◽

Heat Pump ◽

Water Resource ◽

Economic Performance ◽

Waste Heat ◽

Cooling Water ◽

Engineering Practice ◽

Recovery System ◽

Circulating Cooling Water ◽

Water Waste

Industrial circulating cooling water contains a large amount of low-quality energy, which is lost to the environment through cooling towers. It is of great significance and potential to recover the waste heat to improve energy-saving effects and economic efficiency. However, the effect of common water harvesting and energy saving devices is not significant. Heat pumps have been shown to be effective in improving low-quality heat energy in energy conversion systems, although there are not many applications of heat pump scenarios in engineering practice. Based on this, a recovery solution of circulating cooling water waste heat and water resource using lithium bromide absorption heat pump has been put forward. The energy-saving performance of the recovery system was simulated and analyzed using Aspen Plus V10.0 (Bedford, MA, USA) to explore the effects of the parameters of the working medium in evaporators, condensers, absorbers, generators, heat exchangers, etc., and the modelling results indicated that the evaporation pressure and temperature have a great influence on the system COP (coefficient of performance) and can raise the thermal economy of the system. The heat from driving steam and heating capacity both increased with the increase in generating temperature, while the increase in temperature difference between evaporation and condensation inhibits the COP of heat pump systems. Furthermore, economic analyses and comparisons of the recovery solutions were conducted and the recovery solution of circulating cooling water waste heat with heat pump had the best economic performance due to the annual income from the recovery of waste heat and water resource. The static payback period results indicate that the recovery solution from circulating cooling water waste heat with a heat pump has better economic performance than the scenario with a cooling tower. The waste heat recovery solution with a heat pump can improve the thermal economy of the system and has a great guiding significance for engineering practice.

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