A new utilization approach of the waste heat with mid-low temperature in the combined heating and power system integrating heat pump

Kang, Shushuo; Li, Hongqiang; Lei, Jing; Liu, Lifang; Cai, Bo; Zhang, Guoqiang

doi:10.1016/j.apenergy.2015.09.054

Cited by 47 publications

(5 citation statements)

References 24 publications

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“…Another study has investigated coupling a gas turbine and a geothermal heat pump to produce electric energy and hot domestic water. The outcome of such integration has improved the heat pump COP to around 6.95 and increase the combined system efficiency to 3.9% [10]. Another study has proposed a similar thermodynamic combined concept and the results revealed that both thermodynamic laws have improved by approximately 10.5%.…”

Section: Introductionmentioning

confidence: 93%

Impact of Various Combustion Chamber Exhaust Temperatures on a Combined Bryton-ORC Energy Recovery System

Al-Tameemi,

Al-Samari

2023

KEM

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A combined heat and power system has been proposed and evaluated thermodynamically to generate mechanical power and hot water for various applications. The combined system consisted of a gas turbine cycle (GT) to produce the main mechanical power. An Organic Rankine cycle (ORC) is used to convert some of the GT flue gases wasted heat to additional mechanical power. The hot water is produced from two heating levels, in first level the rejected latent heat from the ORC condenser is recovered. While in second heating level the high thermal energy available in the GT working fluid after the compression process is used through a heat exchanger. A thermodynamic simulation is carried out by ASPEN plus package and the thermophysical properties of the working fluids is obtained from REFPROP. The effect of increasing the gas burner flue gases temperature from (700-1250 °C) on the main system design parameters reveals that the overall net power output has declined by 3.5% but it is greater than the standalone GT cycle by 13.4 – 17.6%. In addition, the total thermal energy recovered has declined significantly by 53.7%. Furthermore, the GT thermal efficiency has increased from 16-25% and the combined system has converted the waste heat into hot water with a temperature between 93-48.5 °C to be used in different heating applications.

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Section: Introductionmentioning

confidence: 93%

Impact of Various Combustion Chamber Exhaust Temperatures on a Combined Bryton-ORC Energy Recovery System

Al-Tameemi,

Al-Samari

2023

KEM

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“…Garimella presented a simulation‐based study of an ammonia‐water based absorption cycle to check its feasibility for space cooling and process heating. Kang et al used the geothermal heat source assisted heat pump for domestic heating/cooling with the capability of electricity production through gas turbines. Cui et al presented a performance analysis of a newly proposed two‐stage waste heat recovery (WHR) system to capture low‐grade waste heat.…”

Section: Introductionmentioning

confidence: 99%

Techno‐economic analysis of a novel hybrid heat pump system to recover waste heat and condensate from the low‐temperature boiler exhaust gas

2020

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Summary This paper is based on the proposal of a new waste heat recovery (WHR) system, which can be utilized to heat the boiler return water, boiler supply air, and building heating air. The system is the combination of an indirect contact condensing unit (IDCCU), a mechanical compression heat pump, and two air preheaters. The system is modeled on the basis of mass and energy balance and then thermodynamically analyzed. Improved performance results were obtained in the form of an increase in the boiler's energy efficiency of about 10.47%, with 4.87% increase in exergy efficiency. The coefficient of performance (COP) of the heat pump was increased from 1.23 to 1.45 by the addition of an air heater in the conventional heat pump. The exergy destruction in each component is calculated. Sensitivity analysis was performed to check the influence of different operating parameters on the performance of the WHR system and boiler. It can be observed from the results that for a specific refrigerant temperature and a calculated amount of mass, flow rate can maximize the condensation efficiency of IDCCU by decreasing the flue gas temperature, while the use of the air heater can further reduce the flue gas temperature, and a stream of hot air can be utilized for space heating. A comparison is made with the other system on a performance basis. The results shows a clear difference in efficiencies and profit earned.

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“…It however has a relatively low theoretical COP of 3.6-4 because the heat pump operates at large temperature lift. Kang et al [20] also analysed a parallel system that uses a gas turbine to drive a heat pump and recovers the gas turbine's waste heat to produce hot water, but this system again suffers from a lower heat pump COP due to a high condenser temperature. Schimpf and Span [21] numerically analysed a heat pump system that is capable of running in reverse as an ORC by diverting the working fluid between an expansion valve and pump, depending on the flow direction.…”

Section: Introductionmentioning

confidence: 99%

Investigation of a gas-fuelled water heater based on combined power and heat pump cycles

Liang

Al-Tameemi

2018

Applied Energy

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In this paper, we proposed and demonstrated a novel gas-fuelled hot water system based on combined power and heat pump cycles. It essentially integrates a premixed gas burner, an organic Rankine cycle (ORC) power plant, and an air source heat pump for supplying hot water. An ORC power plant generates mechanical power from the thermal energy produced from the combustion of natural gas in the burner. Subsequently, the generated power directly drives a vapour compression cycle heat pump through a common shaft connecting the expander and the compressor. Cold tap water is headed firstly in the condenser of the heat pump, then in the condenser of the ORC power plant, and finally the flue gas exiting from the burner in a post heater. The flue gas exiting the post heater will be mixed with ambient air to further extract its residual heat in the evaporator of the heat pump. The advantages of the proposed system are threefold. First, the waste heat of the power cycle has been fully recovered. Second, the heat pump operates on a much lower temperature difference, leading to 2 higher COP. Third, it has no electrical generator or motor, avoiding the transduction losses. A comprehensive analysis has been presented in this paper, and the results show that the proposed system can achieve an overall fuel-to-heat efficiency up to 147% when the cold water is heated from 10 to 65 °C and the ambient air temperature is in the range-5 to 5 °C. The research results demonstrated that the proposed technology has a great potential for hot water applications.

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A new utilization approach of the waste heat with mid-low temperature in the combined heating and power system integrating heat pump

Cited by 47 publications

References 24 publications

Impact of Various Combustion Chamber Exhaust Temperatures on a Combined Bryton-ORC Energy Recovery System

Impact of Various Combustion Chamber Exhaust Temperatures on a Combined Bryton-ORC Energy Recovery System

Techno‐economic analysis of a novel hybrid heat pump system to recover waste heat and condensate from the low‐temperature boiler exhaust gas

Investigation of a gas-fuelled water heater based on combined power and heat pump cycles

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