Synergetic process of condensing heat exchanger and absorption heat pump for waste heat and water recovery from flue gas

2020 ◽  
Vol 261 ◽  
pp. 114401 ◽  
Author(s):  
Xiang Wang ◽  
Jiankun Zhuo ◽  
Jianmin Liu ◽  
Shuiqing Li
Keyword(s):  
Heat Exchanger ◽  
Heat Pump ◽  
Flue Gas ◽  
Waste Heat ◽  
Water Recovery ◽  
Absorption Heat Pump ◽  
Condensing Heat Exchanger

Application Study of BCHP System With Absorption Heat Pump of an Urban Original Sewage Source

2010 ◽  
Author(s):  
X. L. Zhao ◽  
L. Fu ◽  
S. G. Zhang ◽  
J. Z. Zhu ◽  
B. M. Huang ◽  
...  
Keyword(s):  
Energy Efficiency ◽  
Heat Exchanger ◽  
Heat Pump ◽  
Flue Gas ◽  
Waste Heat ◽  
Combustion Engine ◽  
Clean Energy ◽  
Absorption Heat Pump ◽  
Efficient Integration ◽  
Sewage Source

A critical issue for BCHP (Building combined cooling heating and power) system is the efficient integration of power generation equipment with different heat utilization technologies. A BCHP system with an urban original sewage source absorption heat pump is proposed. The system is composed of an internal combustion engine, a water-water heat exchanger, a flue gas driven absorption heat pump, a filth block device, a wastewater heat exchanger, and other assistant facilities, such as pumps, fans, and end user devices. In the winter, the waste heat of the flue gas is used to drive absorption heat pump to recover the waste heat of sewage source and the flue gas, and in the summer, the waste heat of the flue gas is used to drive absorption heat pump for cooling, and the heat load of the building is removed to the sewage. In the paper, this kind of system was designed according to the energy consumption of the buildings, and the overall performance of the system in the heating and cooling mode was studied, and the energy efficiency level was analyzed. It is shown that the system is the efficient integration of clean energy and waste heat resource, and the energy efficiency of the system could be improved by 18.5% compared with the conventional BCHP systems.

The Performance Improvement of a 70kWe Natural Gas CHP System

2008 ◽  
Author(s):  
Lin Fu ◽  
Xiling Zhao ◽  
Shigang Zhang ◽  
Yi Jiang ◽  
Hui Li ◽  
...  
Keyword(s):  
Heat Exchanger ◽  
Natural Gas ◽  
Heat Pump ◽  
Flue Gas ◽  
Utilization Efficiency ◽  
Outlet Temperature ◽  
Absorption Heat Pump ◽  
Gas Engine ◽  
Innovative System ◽  
Chp System

It is well known that combined heating and power (CHP) generation permits the energy of the fuel to be more efficiently than electric and thermal separate generation. The paper deals with natural gas CHP system with a 70kWe gas-powered internal combustion engine (ICE), which has been set up at the Tsinghua University energy-saving building, in Beijing, China. The system is composed of an ICE, a flue gas heat exchanger and other heat exchangers. The conventional system’s characteristics is that the gas engine generates power on-site, and the exhaust of the gas engine is recovered by a high temperature flue gas-water heat exchanger, and the jacket water heat is recovered by a water-water heat exchanger to supply heat for district heating system. In order to improve the system’s performance, an innovative system with absorption heat pump is adopted. The exhaust of the gas engine drives an absorption heat pump to recover the flue gas sensible heat and further recover the latent heat, so the outlet temperature of the exhaust could be lowered to 50°C. In this paper, the electrical and thermal performance of the innovative system were tested and compared with conventional cogeneration systems. The test and comparison results show that the innovative CHP system could increase the heat utilization efficiency 10% in winter. All the results provide important insight into CHP performance characteristics and could be valuable references for CHP system’s improvements.

Methods of Thermal Calculations for a Condensing Waste-Heat Exchanger

2014 ◽  
Vol 35 (4) ◽  
pp. 447-461 ◽  
Author(s):  
Paweł Rączka ◽  
Kazimierz Wójs
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Water Vapour ◽  
Flue Gas ◽  
Waste Heat ◽  
Pilot Scale ◽  
Dew Point ◽  
Steam Boiler ◽  
Heat Transfer Area ◽  
Condensing Heat Exchanger

Abstract The paper presents the algorithms for a flue gas/water waste-heat exchanger with and without condensation of water vapour contained in flue gas with experimental validation of theoretical results. The algorithms were used for calculations of the area of a heat exchanger using waste heat from a pulverised brown coal fired steam boiler operating in a power unit with a capacity of 900 MWe. In calculation of the condensing part, the calculation results obtained with two algorithms were compared (Colburn-Hobler and VDI algorithms). The VDI algorithm allowed to take into account the condensation of water vapour for flue gas temperatures above the temperature of the water dew point. Thanks to this, it was possible to calculate more accurately the required heat transfer area, which resulted in its reduction by 19 %. In addition, the influence of the mass transfer on the heat transfer area was taken into account, which contributed to a further reduction in the calculated size of the heat exchanger - in total by 28% as compared with the Colburn-Hobler algorithm. The presented VDI algorithm was used to design a 312 kW pilot-scale condensing heat exchanger installed in PGE Belchatow power plant. Obtained experimental results are in a good agreement with calculated values.

Compact Diesel Engine Waste-Heat Driven Ammonia-Water Absorption Heat Pump Modeling and Performance Maximization Strategies

2021 ◽  
pp. 1-28
Author(s):  
Christopher M. Keinath ◽  
Jared Delahanty ◽  
Srinivas Garimella ◽  
Michael A. Garrabrant
Keyword(s):  
Heat Exchanger ◽  
Water Absorption ◽  
Heat Pump ◽  
Waste Heat ◽  
Cooling Capacity ◽  
Operating Conditions ◽  
Heat Transfer Fluid ◽  
Ammonia Water ◽  
Absorption Heat Pump ◽  
Wide Range

Abstract An investigation of the best ways to achieve optimal performance from a waste-heat-driven ammonia-water absorption heat pump over a wide range of operating conditions is presented. Waste-heat is recovered using an exhaust gas heat exchanger and delivered to the desorber by a heat transfer fluid loop. The absorber and condenser are hydronically coupled in parallel to an ambient heat exchanger for heat rejection. The evaporator provides chilled water for space-conditioning with a baseline cooling capacity of 2 kW. A detailed thermodynamics model is developed to simulate performance and develop strategies to achieve the best performance in both cooling and heating modes over a range of operating conditions. These parametric studies show that improved coefficients of performance can be achieved by adjusting the coupling fluid temperatures in the evaporator and the condenser/absorber as the ambient temperature varies. With the varying return temperatures, the system is able to provide the 2 kW design cooling capacity for a wide range of ambient temperatures.

Modelling and performance analysis of a single stage open absorption heat pump system in aspen plus using aqueous LiBr and HCOOK: A waste moist heat recovery application

2021 ◽  
pp. 095765092110478
Author(s):  
Muhammad Kashif Shahzad ◽  
Yaqi Ding ◽  
Yongmei Xuan ◽  
Neng Gao ◽  
Guangming Chen
Keyword(s):  
Heat Pump ◽  
Heat Recovery ◽  
Process Model ◽  
Waste Heat ◽  
Lithium Bromide ◽  
Aspen Plus ◽  
Coefficient Of Performance ◽  
Water Recovery ◽  
Pump System ◽  
Absorption Heat Pump

Open absorption heat pump (OAHP) system is more viable option to recover waste heat from moist gas as compared to the traditional condensation methods. This promising technology has great potential for latent heat recovery from moist gas, drying process in paper and other industrial heating applications. This study presents the process modelling and comparative analysis of OAHP system in Aspen Plus using two different solutions by adopting part regeneration technique. The promising potassium formate-water (HCOOK/H2O) which has lower causticity, lower costs and better crystallization characteristics is used as an alternative to the caustic lithium bromide-water (LiBr/H2O) solution in this study. Process model of the system is established in Aspen Plus and, the properties validity is confirmed with published experimental and Engineering Equation Solver (EES) library data. A detailed comparative parametric study is carried out to evaluate the effect of influencing parameters on coefficient of performance (COP), water recovery (φ) and heat recovery (ζ) efficiencies. The performance of OAHP system is found to be very similar using different concentrations as 2.13 COP value for 50% LiBr/H2O and 2.19 for 70% HCOOK/H2O solution over design conditions. Similarly, φ is found to be 0.701, 0.688 while ζ as 0.716 and 0.705 for both the absorbents. Moreover, the system’s operational concentration range is 45-61.3% for LiBr/H2O and 55-82.1% for HCOOK/H2O at 135 °C regeneration heat input. Potassium formate solution having quite similar properties to the aqueous lithium bromide is also confirmed to have similar performance trends using 50% and 70% concentrations.

Experimental Study of Natural Gas Combustion Flue Gas Waste Heat Recovery System Based on Direct Contact Heat Transfer and Absorption Heat Pump

2013 ◽  
Author(s):  
Xian Zhou ◽  
Hua Liu ◽  
Lin Fu ◽  
Shigang Zhang
Keyword(s):  
Heat Exchanger ◽  
Flue Gas ◽  
Direct Contact ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Contact Heat ◽  
Absorption Heat Pump ◽  
Return Water ◽  
Recovery System

Condensing boiler for flue gas waste heat recovery is widely used in industries. In order to gain a portion of the sensible heat and latent heat of the vapor in the flue gas, the flue gas is cooled by return water of district heating through a condensation heat exchanger which is located at the end of flue. At low ambient air temperature, some boilers utilize the air pre-heater, which makes air be heated before entering the boiler, and also recovers part of the waste heat of flue gas. However, there are some disadvantages for these technologies. For the former one, the low temperature of the return water is required while the utilization of flue gas heat for the latter one is very limited. A new flue gas condensing heat recovery system is developed, in which direct contact heat exchanger and absorption heat pump are integrated with the gas boiler to recover condensing heat, even the temperature of the return water is so low that the latent heat of vapor in the flue gas could not be recovered directly by the general condensing technologies. Direct contact condensation occurs when vapor in the flue gas contacts and condenses on cold liquid directly. Due to the absence of a solid boundary between the phases, transport processes at the phase interface are much more efficient and quite different from condensation phenomena on a solid surface. Additionally, the surface heat exchanger tends to be more bulky and expensive. In this study, an experimental platform of the new system is built, and a variety of experimental conditions are carried out. Through the analysis of the experimental data and operational state, the total thermal efficiency of the platform will be increased 3.9%, and the system is reliable enough to be popularized.

Numerical Simulation of Low Grade Heat and Water Recovery Using Nanoporous Transport Membrane Condensers Bundle Tubes

2015 ◽  
Author(s):  
Soheil Soleimanikutanaei ◽  
Cheng-Xian Lin ◽  
Dexin Wang
Keyword(s):  
Heat Exchanger ◽  
Flue Gas ◽  
Power Plants ◽  
Ceramic Membrane ◽  
Transport Model ◽  
Waste Heat ◽  
Numerical Study ◽  
Tube Bundle ◽  
Low Grade ◽  
Water Recovery

Low grade waste heat and water recovery using ceramic membrane, is an emerging technology which helps to increase the efficiency of boilers and gas or coal combustors in various industrial processes and conventional power plants. The tube wall of a Transport Membrane Condenser (TMC) based heat exchanger is made of a nano-porous material with high membrane selectivity which is able to extract condensate water from the flue gas in the presence of other non-condensable gases (i.e. CO2, O2 and N2). In this work, a numerical study has been carried out to investigate the effects of transversal pitches of the TMC bundle tubes on the performance of a TMC based cross flow heat exchanger. A simplified multi-species transport model is used to investigate the heat and mass transfer characteristics of a condensing combustion flue gas in a crossflow transport membrane tube bundle. Various transversal (0.4”–0.6”) and longitudinal (0.4”–0.8”) pitches were used. The numerical results revealed that the effect of transversal pitches on the outlet parameters are more pronounced.

Sign in / Sign up

Export Citation Format

Share Document