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Lakes as a heat source for heat pumps – a model study to determine the ecological impact of summer heat transfer
Published in Jochen Bundschuh, Guangnan Chen, D. Chandrasekharam, Janusz Piechocki, Geothermal, Wind and Solar Energy Applications in Agriculture and Aquaculture, 2017
Renata Brzozowska, Maciej Neugebauer, Janusz Piechocki
A heat pump is a device, the function of which is to extract heat from a source at a lower temperature (lower) and transfer it to a target at a higher temperature (upper). To make this achievable, it is necessary to provide the operating power for the heat pump, since the spontaneous flow of heat from a lower temperature body to a higher temperature body is not possible. The ratio of heat given back into the upper source to the energy needed to drive the heat pump is always greater than one. The efficiency of an ideal heat pump depends on the temperature difference of the two heat sources. The smaller it is, the more efficiently the pump is working (Zawadzki, 2003). Heat pumps can be divided into three types:Compressor heat pumpThermoelectric heat pumpAbsorption heat pump.Heat pumps belonging to the first group are the most commonly used in space heating (Kavanaugh and Rafferty, 2014; Petit and Collins, 2011; Rubik, 2011).
Current trends and future prospects of renewable energy-driven desalination (RE-DES)
Published in Hacene Mahmoudi, Noreddine Ghaffour, Mattheus Goosen, Jochen Bundschuh, Renewable Energy Technologies for Water Desalination, 2017
SOL-14 plant coupled to a double-effect absorption heat pump (DEAHP). A prototype of a DEAHP was coupled to a MED unit called the SOL14 plant. A thermal energy consumption of about 115 kJ kg−1 (saturated steam at 180°C) was experimentally obtained with an advanced process, which was developed at the Plataforma Solar de Almería (PSA) research centre by the Spanish government’s Centre for Investigation of Energy, Environment and Technology (CIEMAT) in cooperation with the company Entropie (Alarcón-Padilla and García-Rodríguez, 2007; Alarcón-Padilla et al., 2007, 2008, 2010a, 2010b, 2010c; Palenzuela et al., 2014; García-Rodríguez et al., 2001). This technology did not reach the pre-commercial stage as even such low consumption was not able to compete with RO technology (Table 15.5).
Geothermal energy
Published in Volker Quaschning, Understanding Renewable Energy Systems, 2016
The absorption heat pump’s reboiler brings the ammonia to boil at low temperatures and pressures by means of low-temperature heat, as in a compression heat pump. Water, the solvent, absorbs the gaseous refrigerant in the absorber. The resulting high temperatures can be passed on as useful heat via a heat exchanger. The solvent pump passes the solution on to the compressor. Because the solvent pump does not require the same high pressure as in a compression heat pump, less electricity is needed. The separator then takes advantage of the different boiling points of the refrigerant and solvent – here, ammonia and water – to break down the solution into these two components. In this process, thermal energy is consumed. This heat can come from the combustion of natural gas or biogas, but solar thermal and geothermal heat also suffice. Within the condenser, the now separated gaseous refrigerant condenses under high pressure and high temperatures. The condensation heat can also be used as useful heat. The fluid refrigerant passes through an expansion valve to return to the reboiler, and the solvent returns to the absorber, thereby completing the cycle. Figure 8.12 shows how an absorption heat pump works.
Multiobjective optimisation of absorption heat pump performance with double internal irreversibility based algorithm NSGAII: case of three-heat-source model
Published in International Journal of Ambient Energy, 2022
Paiguy Armand Ngouateu Wouagfack, Germaine Mabou Ninkam, Réné Tchinda
The purpose of an absorption heat pump system is to reduce or even eliminate the mechanical energy consumption by substituting a relatively high temperature heat consumption. The cycle is based on thermo-compression rather than mechanical compression. In the absorption heat pumps, the suction and discharge functions of the mechanical compressor are replaced by the affinity of a fluid with respect to the refrigerant. Compared to vapour compression systems (Fu et al. 2009; Zhao, Fu, and Zhang 2010), absorption heat pump systems have major advantages: use of unused heat sources such as: solar energy, geothermal energy and heat lost in vapours within factories; save energy in the use of primary energy resources; are less harmful to the environment, operate with a simple mechanism; provide reliable and quiet warming.
Experimental investigation on using building shower drain water as a heat source for heat pump systems
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2020
Ataollah Khanlari, Adnan Sözen, Bayram Sahin, Giovanni Di Nicola, Faraz Afshari
The potential of wastewater utilization as a heat source for heat pumps to supply hot water was investigated by Meggers and Leibundgut (2011). The feasibility of the sauna wastewater as a heat source for heat pump was analyzed by Baek et al. (2005). The annual average COP value of the designed heat pump was measured as approximately 4.8. In another study, wastewater deriving from a common bathroom was utilized in a heat pump and daily mean COP was monitored for over an entire month. The operating cost of a wastewater source heat pump was compared to that of conventional water heating systems (Chao et al. 2013). Drained water from showers was collected in a water pool and two different heat recovery mechanisms were proposed using electrical and absorption heat pumps. When the filtered wastewater reaches a certain volume, the heat pump system will begin working and recycling heat. It was reported that direct-fired absorption heat pump has lower energy consumption, lower operating cost, less pollution, and shorter payback period (Liu, Fu, and Zhang 2014). Domestic drain water was used as a heat source for a house heat pump and the performance of the heat pump installed for water heating was studied experimentally by Guo et al. (2019). Their finding showed that using drain water as a heat source, increased COP from 1.91 to 4.82.