The D3.3 reports the design efforts, experimental tests and optimization activities carried out on the hybrid chiller produced by FAHR. These activities are the core aims of T3.2 "Adsorption HP upgrade and guidelines for installation/combination with other H&C technologies" whose task leader is FAHR. The connected activities related to the guidelines for the hybrid chiller installation were already carried out and are fully explained in D3.4. FAHR was in charge to design and manufacture the hybrid chiller, ITAE lead the experimental test activities obtaining the full performance characterization of this technology and an optimization of the control strategy. FAHR designed a hybrid chiller composed by a sorption unit and a compression one connected in parallel to the on the load side (cold side) and in series connection to the heat sink (heat rejection side). The adsorption and compression heat pumps operate in parallel to each other supplying cold water to one common cold consumer. The adsorption chiller covers the base load, while the compression chiller is activated only if the required parameter cannot be achieved by the adsorption unit alone. Initially, a cascade layout was considered as the best solution for the SunHorizon project design. However, during the engineering works and tests it has been noted, that considering its specific advantages and drawbacks, the parallel layout is the most beneficial for the intended application. Several innovations were introduced in this technology, they regard the adsorber's coating, the heat exchangers and the process modules, more details about these aspects are explained in D3.11. A further innovation introduced, thanks to the experimental tests and ITAE support, is the optimization of the control strategy that will let to improve the efficiency and reliability of the hybrid chiller For the experimental tests, the hybrid chiller was shipped to the CNR-ITAE labs in Messina, an intense experimental campaign was planned with the aim to produce a full performance map of the tested technology and deeply investigate on its optimisation. During the tests several troubles with the control settings were founded and solved through the continuous exchange of information between FAHR and ITAE. Finally, a novel design of control strategy was suggested by ITAE and implemented by FAHR, thus achieving a global improvement of reliability and efficiency of the hybrid chiller. The results of the tests let also to produce the performance map of the chiller and a mathematical correlation, based on statistical regression, that let to easily calculate the performance by a polynomial expression. This last finding is useful for the modelling of the hybrid chiller and its implementation on simulations and AI interfaces. In conclusion, the experimental characterization showed that the hybrid configuration lets to achieve a lower improvement, in terms of performance, if compared with a compression chiller than the expected one. This was mainly related to the design of MT circuits and to the controls. The new control strategy will let to increase the efficiency and the reliability of the system, thus making the hybrid chiller more competitive of a compression one, in terms of cooling power and EER.
Final design of the hybrid sorption/compression chiller
2021
Abstract
The D3.3 reports the design efforts, experimental tests and optimization activities carried out on the hybrid chiller produced by FAHR. These activities are the core aims of T3.2 "Adsorption HP upgrade and guidelines for installation/combination with other H&C technologies" whose task leader is FAHR. The connected activities related to the guidelines for the hybrid chiller installation were already carried out and are fully explained in D3.4. FAHR was in charge to design and manufacture the hybrid chiller, ITAE lead the experimental test activities obtaining the full performance characterization of this technology and an optimization of the control strategy. FAHR designed a hybrid chiller composed by a sorption unit and a compression one connected in parallel to the on the load side (cold side) and in series connection to the heat sink (heat rejection side). The adsorption and compression heat pumps operate in parallel to each other supplying cold water to one common cold consumer. The adsorption chiller covers the base load, while the compression chiller is activated only if the required parameter cannot be achieved by the adsorption unit alone. Initially, a cascade layout was considered as the best solution for the SunHorizon project design. However, during the engineering works and tests it has been noted, that considering its specific advantages and drawbacks, the parallel layout is the most beneficial for the intended application. Several innovations were introduced in this technology, they regard the adsorber's coating, the heat exchangers and the process modules, more details about these aspects are explained in D3.11. A further innovation introduced, thanks to the experimental tests and ITAE support, is the optimization of the control strategy that will let to improve the efficiency and reliability of the hybrid chiller For the experimental tests, the hybrid chiller was shipped to the CNR-ITAE labs in Messina, an intense experimental campaign was planned with the aim to produce a full performance map of the tested technology and deeply investigate on its optimisation. During the tests several troubles with the control settings were founded and solved through the continuous exchange of information between FAHR and ITAE. Finally, a novel design of control strategy was suggested by ITAE and implemented by FAHR, thus achieving a global improvement of reliability and efficiency of the hybrid chiller. The results of the tests let also to produce the performance map of the chiller and a mathematical correlation, based on statistical regression, that let to easily calculate the performance by a polynomial expression. This last finding is useful for the modelling of the hybrid chiller and its implementation on simulations and AI interfaces. In conclusion, the experimental characterization showed that the hybrid configuration lets to achieve a lower improvement, in terms of performance, if compared with a compression chiller than the expected one. This was mainly related to the design of MT circuits and to the controls. The new control strategy will let to increase the efficiency and the reliability of the system, thus making the hybrid chiller more competitive of a compression one, in terms of cooling power and EER.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
