Heat Pump and Steam Accumulator Electrical Energy Storage System (Esheatpac System)

Esheatpac is an electricity storage system that combines heat pump, steam accumulator, and steam-water cycles technologies. It includes a heat pump, powered by an electric compressor, which produces saturated steam that is stored in steam accumulators as pressurized liquid water. Later, this steam produces electricity in a turbo-generator. Combination of efficiency of heat pump and Rankine cycle heat rate allows reaching efficiencies of up to 100% or higher, without requiring any auxiliary fuel. Efficiencies of up to 124.5% can be achieved by providing natural gas, with the combination of heat pumps with COP equals 2.65 and Rankine cycles with heat rate of 47%. The above means that it is possible to extract from the system the same or higher amount of electricity that enters it, after remaining stored for the time required, up to almost 25% more. Esheatpac is an optimal solution for when it is required to store large amounts of electricity and medium discharge times. Today, the only storage systems that meet these conditions are pumped hydro storage (PHS) and compressed air energy storage (CAES). Compared to PHS, Estheapc presents the advantages of its better performance, a maximum of 85%, and less environmental and public opposition problems, in addition to the limitations to find suitable locations. Compared to CAES, it presents the advantages of its better performance, 50% in current plants, and much lower storage capacities, on the order of seven times less, which also means a lower material investment

Proposal Of Optimized Solutions For Joint Use And Hybridization Of Energy Storage Systems And Combined Cycles Or Renewable Energy Plants

This article describes an electrical energy storage system with a heat pump and steam accumulators or molten salt storage, and solutions are proposed for the hybridization of this storage system with power plants, mainly combined cycle and renewable, already existing or new construction. As a result of the development of these solutions, it is concluded that these hybridizations allow each one of the plants to operate with its nominal performance in peak hours and with a similar or higher performance in off-peak hours or periods of low prices, that is, , the electrical energy supplied to the network for each thermal or electrical kilowatt that feeds the plants is similar or higher when this electrical energy is previously stored. These high efficiencies after storage are achieved by combining heat pump performance (COP greater than 2) and Rankine cycle heat rate. In summary, it is possible to optimize the performance of the power plants during all hours of the day and optimize costs due to the joint use of equipment and systems. Highlights Hybridization combined cycles, renewables and electricity storage can become a useful tool.Hybridization can optimize the joint operation of the electrical system. Proposed hybridization achieves the same performances after storing the energy. Proposed hybridization allows sharing of equipment and systems

Effects of pre-operative isolation on postoperative pulmonary complications after elective surgery: an international prospective cohort study an international prospective cohort study

We aimed to determine the impact of pre-operative isolation on postoperative pulmonary complications after elective surgery during the global SARS-CoV-2 pandemic. We performed an international prospective cohort study including patients undergoing elective surgery in October 2020. Isolation was defined as the period before surgery during which patients did not leave their house or receive visitors from outside their household. The primary outcome was postoperative pulmonary complications, adjusted in multivariable models for measured confounders. Pre-defined sub-group analyses were performed for the primary outcome. A total of 96,454 patients from 114 countries were included and overall, 26,948 (27.9%) patients isolated before surgery. Postoperative pulmonary complications were recorded in 1947 (2.0%) patients of which 227 (11.7%) were associated with SARS-CoV-2 infection. Patients who isolated pre-operatively were older, had more respiratory comorbidities and were more commonly from areas of high SARS-CoV-2 incidence and high-income countries. Although the overall rates of postoperative pulmonary complications were similar in those that isolated and those that did not (2.1% vs 2.0%, respectively), isolation was associated with higher rates of postoperative pulmonary complications after adjustment (adjusted OR 1.20, 95%CI 1.05–1.36, p = 0.005). Sensitivity analyses revealed no further differences when patients were categorised by: pre-operative testing; use of COVID-19-free pathways; or community SARS-CoV-2 prevalence. The rate of postoperative pulmonary complications increased with periods of isolation longer than 3 days, with an OR (95%CI) at 4–7 days or ≥ 8 days of 1.25 (1.04–1.48), p = 0.015 and 1.31 (1.11–1.55), p = 0.001, respectively. Isolation before elective surgery might be associated with a small but clinically important increased risk of postoperative pulmonary complications. Longer periods of isolation showed no reduction in the risk of postoperative pulmonary complications. These findings have significant implications for global provision of elective surgical care. We aimed to determine the impact of pre-operative isolation on postoperative pulmonary complications after elective surgery during the global SARS-CoV-2 pandemic. We performed an international prospective cohort study including patients undergoing elective surgery in October 2020. Isolation was defined as the period before surgery during which patients did not leave their house or receive visitors from outside their household. The primary outcome was postoperative pulmonary complications, adjusted in multivariable models for measured confounders. Pre-defined sub-group analyses were performed for the primary outcome. A total of 96,454 patients from 114 countries were included and overall, 26,948 (27.9%) patients isolated before surgery. Postoperative pulmonary complications were recorded in 1947 (2.0%) patients of which 227 (11.7%) were associated with SARS-CoV-2 infection. Patients who isolated pre-operatively were older, had more respiratory comorbidities and were more commonly from areas of high SARS-CoV-2 incidence and high-income countries. Although the overall rates of postoperative pulmonary complications were similar in those that isolated and those that did not (2.1% vs 2.0%, respectively), isolation was associated with higher rates of postoperative pulmonary complications after adjustment (adjusted OR 1.20, 95%CI 1.05–1.36, p = 0.005). Sensitivity analyses revealed no further differences when patients were categorised by: pre-operative testing; use of COVID-19-free pathways; or community SARS-CoV-2 prevalence. The rate of postoperative pulmonary complications increased with periods of isolation longer than 3 days, with an OR (95%CI) at 4–7 days or ≥ 8 days of 1.25 (1.04–1.48), p = 0.015 and 1.31 (1.11–1.55), p = 0.001, respectively. Isolation before elective surgery might be associated with a small but clinically important increased risk of postoperative pulmonary complications. Longer periods of isolation showed no reduction in the risk of postoperative pulmonary complications. These findings have significant implications for global provision of elective surgical care