The maximum coefficient of performance of thermoelectric heat pumps

1996 ◽  
Vol 17 (1) ◽  
pp. 22-28 ◽  
Author(s):  
J. Chen ◽  
B. Andresen
Keyword(s):  
Heat Pumps ◽  
Coefficient Of Performance ◽  
Maximum Coefficient ◽  
Thermoelectric Heat

Entropy Production and Thermoelectric Device Performance

1984 ◽  
Vol 106 (4) ◽  
pp. 881-885
Author(s):  
E. F. Thacher
Keyword(s):  
Thermal Efficiency ◽  
Isotropic Material ◽  
Heat Pumps ◽  
Coefficient Of Performance ◽  
Thermoelectric Device ◽  
Device Performance ◽  
Thermoelectric Generators ◽  
Integral Forms ◽  
Nonsteady State ◽  
Thermoelectric Heat

Integral forms for the thermal efficiency of thermoelectric generators, the coefficient of performance of thermoelectric refrigerators, and the coefficient of performance of thermoelectric heat pumps are derived. These forms are obtained for the isotropic material, nonsteady-state, nonadiabatic leg surface case. An example of the use of these forms is given.

Heat transfer effect on optimal performance of two-stage thermoelectric heat pumps

2007 ◽  
Vol 221 (12) ◽  
pp. 1635-1641 ◽  
Author(s):  
L Chen ◽  
J Li ◽  
F Sun
Keyword(s):  
Heat Transfer ◽  
Heat Pump ◽  
Analytical Formula ◽  
Electrical Current ◽  
Heat Pumps ◽  
Coefficient Of Performance ◽  
Two Stage ◽  
Thermo Electric ◽  
Heating Load ◽  
Thermoelectric Heat

A model of two-stage semiconductor thermoelectric heat pumps with external heat transfer and internal irreversibility is built. Performance of the heat pump with Newton's heat transfer law is analysed and optimized using the combination of finite-time thermodynamics and non-equilibrium thermodynamics. The analytical formula about heating load versus working electrical current, and the coefficient of performance (COP) versus working electrical current are derived. For the fixed total number of thermoelectric elements, the ratio of number of thermo-electric elements of top stage to the total number of thermoelectric elements is also optimized for maximizing the heating load and the COP of the thermoelectric heat pump. The effects of design factors on the performance are analysed.

Plate Heat Exchanger Adsorber for a Regenerative Adsorption Heat Pump

2004 ◽  
Author(s):  
Michael A. Lambert ◽  
Benjamin J. Jones
Keyword(s):  
Heat Exchanger ◽  
Waste Heat ◽  
Heat Pumps ◽  
Coefficient Of Performance ◽  
Cooling Power ◽  
Plate Heat ◽  
Solid Adsorbent ◽  
Adsorption Heat Pump ◽  
Pin Fins ◽  
Maximum Coefficient

The state of the art in regenerative adsorption (solid-vapor) heat pumps achieved to date is a maximum Coefficient of Performance for Cooling (COPC) of 1.1 with 70% regeneration of waste heat. A number of configurations for the heat exchanger within the adsorbent bed have been investigated, including concentric tube, shell and tube, serpentine flat pipe, spiral flat pipe, and single-pass plate type. However, to date, compact (or multiple pass plate) heat exchangers for use with adsorbent beds have not been studied. This investigation explains the challenges involved in this application, and describes the design and analysis of three configurations of a compact heat exchanger for use with solid adsorbent. The prinicipal figure of merit affecting both coefficient of performance, COPC, and specific cooling power, SCP (W cooling per kg adsorbent), is defined as NTU divided by the ratio of non-adsorbent (“dead”) to adsorbent (“live”) thermal masses. The best of the three configurations consists of thin adsorbent (zeolite) tiles epoxied to the heat exchanger plates (sheets) with screen wire pin fins in the oil passages to enhance heat transfer.

scholarly journals Heat Pump Bridge Analysis Using the Modified Energy Transfer Diagram

Energies ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 137
Author(s):  
Florian Schlosser ◽  
Heinrich Wiebe ◽  
Timothy G. Walmsley ◽  
Martin J. Atkins ◽  
Michael R. W. Walmsley ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Heat Pump ◽  
Heat Recovery ◽  
Heat Pumps ◽  
Coefficient Of Performance ◽  
Combined Application ◽  
Recovery Potential ◽  
Composite Curve ◽  
And Performance ◽  
The Individual

Heat pumps are the key technology to decarbonise thermal processes by upgrading industrial surplus heat using renewable electricity. Existing insight-based integration methods refer to the idealised Grand Composite Curve requiring the full exploitation of heat recovery potential but leave the question of how to deal with technical or economic limitations unanswered. In this work, a novel Heat Pump Bridge Analysis (HPBA) is introduced for practically targeting technical and economic heat pump potential by applying Coefficient of Performance curves into the Modified Energy Transfer Diagram (METD). Removing cross-Pinch violations and operating heat exchangers at minimum approach temperatures by combined application of Bridge Analysis increases the heat recovery rate and reduce the temperature lift to be pumped at the same time. The insight-based METD allows the individual matching of heat surpluses and deficits of individual streams with the capabilities and performance of different market-available heat pump concepts. For an illustrative example, the presented modifications based on HPBA increase the economically viable share of the technical heat pump potential from 61% to 79%.

scholarly journals Factors Shaping A/W Heat Pumps CO₂ Emissions—Evidence from Poland

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1576
Author(s):  
Piotr Jadwiszczak ◽  
Jakub Jurasz ◽  
Bartosz Kaźmierczak ◽  
Elżbieta Niemierka ◽  
Wandong Zheng
Keyword(s):  
Air Quality ◽  
Power System ◽  
Heat Pump ◽  
Heat Pumps ◽  
Hot Water ◽  
Coefficient Of Performance ◽  
Conventional Heating ◽  
Additional Stress ◽  
The European Union ◽  
Energy Mix

Heating and cooling sectors contribute to approximately 50% of energy consumption in the European Union. Considering the fact that heating is mostly based on fossil fuels, it is then evident that its decarbonization is one of the crucial tasks for achieving climate change prevention goals. At the same time, electricity sectors across the globe are undergoing a rapid transformation in order to accommodate the growing capacities of non-dispatchable solar and wind generators. One of the proposed solutions to achieve heating sector decarbonization and non-dispatchable generators power system integration is sector coupling, where heat pumps are perceived as a perfect fit. Air source heat pumps enable a rapid improvement in local air quality by replacing conventional heating sources, but at the same time, they put additional stress on the power system. The emissions associated with heat pump operation are a combination of power system energy mix, weather conditions and heat pump technology. Taking the above into consideration, this paper presents an approach to estimate which of the mentioned factors has the highest impact on heat pump emissions. Due to low air quality during the heating season, undergoing a power system transformation (with a relatively low share of renewables) in a case study located in Poland is considered. The results of the conducted analysis revealed that for a scenario where an air-to-water (A/W) heat pump is supposed to cover space and domestic hot water load, its CO2 emissions are shaped by country-specific energy mix (55.2%), heat pump technology (coefficient of performance) (33.9%) and, to a lesser extent, by changing climate (10.9%). The outcome of this paper can be used by policy makers in designing decarbonization strategies and funding distribution.

Modeling and Design of Building-Integrated Thermoelectrics

2011 ◽  
Author(s):  
Leon M. Headings ◽  
Gregory N. Washington
Keyword(s):  
Thermal Response ◽  
Heat Pumps ◽  
Coefficient Of Performance ◽  
Conventional Heating ◽  
Net Energy ◽  
Arbitrary Boundary ◽  
Heating And Cooling ◽  
Temperature Oscillations ◽  
Wall Structures ◽  
And Control

The goal of this research is to develop a framework for replacing conventional heating and cooling systems with distributed, continuously and electrically controlled, building-integrated thermoelectric (BITE) heat pumps. The coefficient of performance of thermoelectric heat pumps increases as the temperature difference across them decreases and as the amplitude of temperature oscillations decreases. As a result, this research examines how thermal insulation and mass elements can be integrated with thermoelectrics as part of active multi-layer structures in order to minimize net energy consumption. In order to develop BITE systems, an explicit finite volume model was developed to model the dynamic thermal response of active multi-layer wall structures subjected to arbitrary boundary conditions (interior and exterior temperatures and interior heat loads) and control algorithms. Using this numerical model, the effects of wall construction on net system performance were examined. These simulation results provide direction for the ongoing development of BITE systems.

Preliminary Feasibility Study of Groundwater Source Geothermal Heat Pumps in Mason County and the American Bottoms Area, Illinois

2014 ◽  
Author(s):  
Xinli Lu ◽  
David R. Larson ◽  
Thomas R. Holm
Keyword(s):  
Ground Surface ◽  
Heat Pumps ◽  
Coefficient Of Performance ◽  
Weather Data ◽  
Single Family ◽  
Geothermal Heat ◽  
Geothermal Heating ◽  
Heating And Cooling ◽  
Groundwater Source ◽  
Mason County

Groundwater source heat pumps exploit the difference between the ground surface temperature and the nearly constant temperature of shallow groundwater. This project characterizes two areas for geothermal heating and cooling potential, Mason County in central Illinois and the American Bottoms area in southwestern Illinois. Both areas are underlain by thick sand and gravel aquifers and groundwater is readily available. Weather data, including monthly high and low temperatures and heating and cooling degree days, were compiled for both study areas. The heating and cooling requirements for a single-family house were estimated using two independent models that use weather data as input. The groundwater flow rates needed to meet these heating and cooling requirements were calculated using typical heat pump coefficient of performance values. The groundwater in both study areas has fairly high hardness and iron concentrations and is close to saturation with calcium and iron carbonates. Using the groundwater for cooling may induce the deposition of scale containing one or both of these minerals.

scholarly journals Heat pump systems: A mini review

2021 ◽  
Vol 4 (2) ◽  
pp. 73-81
Author(s):  
Mohammad Omar Temori ◽  
František Vranay
Keyword(s):  
Heat Pump ◽  
Electricity Consumption ◽  
Cost Savings ◽  
Electrical Energy ◽  
Primary Energy ◽  
Heat Pumps ◽  
Coefficient Of Performance ◽  
Heating And Cooling ◽  
Ground Source ◽  
Reduce Electricity Consumption

In this work, a mini review of heat pumps is presented. The work is intended to introduce a technology that can be used to income energy from the natural environment and thus reduce electricity consumption for heating and cooling. A heat pump is a mechanical device that transfers heat from one environmental compartment to another, typically against a temperature gradient (i.e. from cool to hot). In order to do this, an energy input is required: this may be mechanical, electrical or thermal energy. In most modern heat pumps, electrical energy powers a compressor, which drives a compression - expansion cycle of refrigerant fluid between two heat exchanges: a cold evaporator and a warm condenser. The efficiency or coefficient of performance (COP), of a heat pump is defined as the thermal output divided by the primary energy (electricity) input. The COP decreases as the temperature difference between the cool heat source and the warm heat sink increases. An efficient ground source heat pump (GSHP) may achieve a COP of around 4. Heat pumps are ideal for exploiting low-temperature environmental heat sources: the air, surface waters or the ground. They can deliver significant environmental (CO2) and cost savings.

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