Adsorption gas Heat Pump fuelled with hydrogen enriched natural gas blends: The analytical simulation model development and validation

This study deals with the implementation of an analytical model to simulate the energy performance associated to a commercial Gas adsorption Heat Pump, when H2NG (Hydrogen Enriched Natural Gas) blends are used as fuel. In detail, a water source heat pump manufactured by Robur (GAHP-WS) has been used as a reference device for building the simulation model within the MATLAB-Simulink environment. Thereafter, the simulation results have been validated by the experimental campaign, testing on field and in actual operating conditions the heat pump. Specifically, the model has been developed by implementing the WaterAmmonia mass and energy balances for each component. It is able to evaluate fuel consumption, efficiency in terms of GUE, required thermal power from the cold heat sink as well as the water outlet temperature at the evaporator, once the heating load is used as the main input. The experimental campaign for the model calibration and validation has been carried out over the winter season. Additionally, the heat pump performance has been detected when it operates to supply hot water at 60 °C and 55 °C, and it is fuelled with growing hydrogen fractions, starting from 0% vol., 5% vol. up to 10% vol. In the end, the standard errors as well as the relative ones affecting the main output parameters have computed for the validation process. From the outcomes it emerges that the average relative standard error related to all load conditions is lower than 2.5% for natural gas operation. On the contrary, it ranges between 2.5% and 4% when H2NG at 5% and 10% by volume have been burnt

Energy-environmental experimental campaign on a commercial CHP fueled with H2NG blends and oxygen enriched air hailing from on-site electrolysis

It is well-known that the renewable electricity excess can be converted into hydrogen for implementing power to gas strategy. Thus, the hydrogen injection in existing natural gas pipelines is a foreseeable option to avoid its storage criticalities and for greening the NG sector. H2NG blends can be fired within CHP engines as well as in other conversion systems, offering better energy performance and reducing the environmental impact as well, once adjustments on combustion setup have been applied. The on-site H2 production for the NG enrichment by an alkaline electrolysis could be more effective whether the oxygen was fruitfully recovered instead of venting it out like a by-product. This study explores the possibility to use that waste oxygen to chemically supercharge the air-fuel mixture, once a widespread micro-CHP technology, based on a reciprocating engine, is fuelled with H2NG blends. So, this paper reports the CHP performance, advantages, drawbacks and technical features, when H2NG blends, ranging in 0%–18% vol. Burn in partial oxy-fuel conditions. An energy and environmental analysis have been carried out, discussing the engine gains, losses and pollutants emissions, when oxygen content varies up to 22% vol. The VolksWagen Blue Tender CHP engine has been used for the on-field tests

The potential role of trans-critical CO2 heat pumps within a solar cooling system for building services: The hybridised system energy analysis by a dynamic simulation model

The rotary desiccant wheels application in the air conditioning systems are used for the air dehumidification by means of hygroscopic layers for water vapor adsorption. Nevertheless, external heat sources are required for water desorption to close the air treatment cycle. This paper investigates on the possibility to integrate in that cycle a new component, such as the trans-critical CO2 heat pump, to reduce the contribution of external thermal sources. In so doing, the high temperature waste heat discharged by the heat pump hot sink can be fruitfully exploited. Additionally, a PV array has been added to the typical layout based on the solar collectors, in order to assure the heat pump electrical driving. The energy analysis is carried out by calculating the energy performance indicators of the whole cooling system, simulating it by a dynamic model built in the MATLAB SIMULINK environment. Specifically, an air handling unit has been properly sized to supply cooling load to a reference conference hall of 1200 m3, with changes in boundary conditions (i.e. solar radiation, daily temperature and relative humidity variations). Indeed, three different cities representing the most typical Italian climatic zones, have been considered for assessing the proposed technical option suitability

The "Lazio Network" experience. The first Italian regional research group on the Enhanced Recovery After Surgery (ERAS) program. A collective database with 1200 patients in 2016-2017

AIM: Enhanced Recovery After Surgery (ERAS) guidelines represent one of the most important steps forward in colorectal surgery in the last ten years. Despite the well-known and demonstrated positive impact on the clinical outcomes that this pathway provides, a cultural revolution in patient management is needed. This is not easy to obtain, especially in small and peripheral centers. In Italy, the diffusion of minimally invasive surgery and "fast-track" perioperative management of the patient is rapidly spreading, even in the central and southern regions. However, in these regions, the percentage of laparoscopic colorectal procedures is dramatically less than in the north of Italy. In this context, the idea of a research group based in Rome focused on the development and spreading of ERAS protocols in the Lazio Region was developed.METHODS: A research group, based in Rome, was founded in December 2016 to evaluate the diffusion of the ERAS program over the main colorectal centers of the region. This "Lazio Network" began with a group of surgeons and anesthesiologists from 5 hospitals. After one and half years, the project now includes 17 hospitals in the region. A multicenter database was created, including consecutive patients who underwent laparoscopic colorectal resection following the ERAS program in the participating centers between January 2016 and December 2017.RESULTS: Data for more than 1200 patients were collected over the observed period. The rate of minimally invasive surgery was higher compared to the regional rate (90% vs. 30%), adherence to the ERAS pathway was around 60% of the items per patient. A clinical study will result from this database. The objective is to evaluate the mean number of ERAS items applied, the most common and uncommon items applied and the influence of this application on the clinical outcomes.CONCLUSIONS: The adoption of the ERAS program is rapidly increasing even in central Italian regions, even though the total rate of minimally invasive surgery procedures still low. Benefits in terms of clinical outcomes will be evaluated from the analysis of a multi-center database of patients treated between January 2016 and December 2017, including more than 1200 patients