Search

Abstract: Heat transformation based on adsorption/desorption of water in microporous adsorbents has been considered for the application as adsorption chiller (ACS), adsorption heat pump (AHP) or thermochemical storage (TCS) since the 1980s. Unfortunately, most of the available adsorbents like zeolites were not optimized for the use in these processes as they originally had been developed for gas separation or catalysis processes. Within the last decade, intensive research on adsorbents yielded in improved and very promising new sorption materials with an enhanced adsorption capacity. This work gives a broad overview on current developments on materials including the new class of metal-organic frameworks for the use in adsorption processes for heat storage and transformation. [Copyright &y& Elsevier]

This paper describes the prototype of a small adsorption heat pump working on the adsorption pair silica gel-water. The developed system consists of two modules, each containing an adsorption reactor and a second heat exchanger for evaporation and condensation of the working fluid. The two modules are operated periodically in order to obtain a quasi-continuous heating or cooling output. A reliable control unit has been developed and implemented in the machine. Hot water provided at temperatures of 80°C to 95°C is used to drive the machine, and heat from the low-temperature heat source (10°C to 20°C) is upgraded to the intermediate temperature level of about 35°C to 45°C, which is suitable for low-temperature heating systems such as wall or floor heating installations. For cooling applications, chilled water of 10°C to 15°C is produced in an almost continuous mode. The first prototypes have been tested. Heating coefficients of performance (COPs) of more than 1.3 and cooling COPs for air-conditioning purposes (12°C to 15°C) of 0.5 have been achieved. The machine provided a mean heating power of up to 15 kW and a cooling power of up to 8 kW. [ABSTRACT FROM AUTHOR]

This numerical study evaluates and compares four different flexibility and storage options in building energy systems (batteries, fuel switch, water tanks, and thermal building mass) in terms of potential improvements in load scheduling and energy efficiency. Using a generic modern office building with concrete core conditioning as an example, two different supply concepts (one based on a heat pump, one based on a CHP unit) are considered. A novel hybrid control concept is applied which is designed to be compatible with state-of-the-art controllers implemented in the field. The results show that batteries are the most technically attractive options in terms of grid support, efficiency and ease of implementation. Fuel switch is comparably straightforward to implement, but provides significant benefits only for the considered CHP system. Water tanks with a capacity of about two full operation hours offer nearly the same flexibility as much larger tanks, but negatively influence the efficiency of heat pump systems. The thermal building mass can be used effectively and efficiently for thermal storage, particularly in the heating season, but this is technically challenging to realize. It is shown that current electricity prices do not offer sufficient variations to stimulate grid-supportive operation. [ABSTRACT FROM AUTHOR]

Highlights: [•] 135 systems from 88 companies based in 11 countries were found. [•] We present detailed analyses of many system and component related characteristics. [•] We show that solar energy is widely used as energy source for heat pumps. [•] We present technical solutions for the combination of solar thermal and heat pumps. [Copyright &y& Elsevier]

• Novel methodology for calculating cost-optimized refurbishment roadmaps is presented. • Coupling of building model for refurbishment and system model for heating technologies. • Refurbishment roadmap include timing and refurbishment measures for specific buildings. • Applying the optimization achieves cost savings of 6–16 % and CO 2 savings of 6–59 % • Heat pumps play a central role in the context of CO 2 reduction. A novel methodology for calculating optimized refurbishment roadmaps is developed in this paper. The aim of the roadmaps is to determine when and how should which component of the building envelope and heat generation system be refurbished to achieve the lowest net present value. The integrated optimization approach couples a particle swarm optimization algorithm with a dynamic building simulation of the building envelope and the heat supply system. Due to a free selection of implementation times and refurbishment depth, the optimization method achieves the lowest net present value and high CO 2 reduction and is therefore an important contribution to achieve climate neutrality in the building stock. The method is exemplarily applied to a multi-family house built in 1970. In comparison to a standard refurbishment roadmap, cost savings of 6–16 % and CO 2 savings of 6–59 % are possible. The sensitivity of the refurbishment roadmap measures is analyzed on the basis of a parametric analysis. Robust optimization results are obtained with a mean refurbishment level of approx. 50 kWh/m2/a of the building envelope. The preferred heat generation system is a bivalent brine-heat pump system with a share of 70 % of the heat load being covered by the electric heat pump. [ABSTRACT FROM AUTHOR]