Diagnostic Protocol for Thermal Performance of District Heating Pipes in Operation. Part 2: Estimation of Present Thermal Conductivity in Aged Pipe Insulation

Buried and operating district heating (DH) pipes are exposed to thermal degradation of their polyurethane (PUR) insulation over time, and their status is hard to assess without excavation. By using DH pipe valves in manholes as measurement points during a shutdown with an ensuing cooling period, non-destructive assessments can be performed. This study compares new improved field measurements with numerical simulations of the temperature decline in drainage valves and shutdown valves. The drainage valve measurements were used to thermally assess part of a buried DH network. Results indicate that by using the drainage valves as measurement points in a cooling method, the thermal conductivity of the buried DH network could be predicted with an accuracy of >95%. In addition, a general diagnostic protocol has been established for assessing the thermal status of a DH network, ready for network owners to use.

Diagnostic Protocol for Thermal Performance of District Heating Pipes in Operation. Part 1: Estimation of Supply Pipe Temperature by Measuring Temperature at Valves after Shutdown

This study evaluates temperatures measured at district heating (DH) valves in manholes and their usability for non-destructively assessing the thermal performance of buried DH pipes. The study was conducted as a field test in which part of a DH network was shut down and the temperature decline in the valves was analysed in terms of absolute temperature and thermal response time from the DH pipe to the top of the valve. The calculated and measured supply pipe temperatures by the drainage valves were in good agreement, with 1% deviation. The valve measurement analysis from this study shows that the drainage valve has good potential to serve as a measurement point for assessing the thermal status of a DH network. However, the shutdown valve measurements were greatly affected by the manhole environment.

Thermal modeling of a Swiss urban aquifer and implications for geothermal heat pump systems

The progressive electrification of the building conditioning sector in recent years has greatly contributed to reducing greenhouse gas emissions by using renewable energy sources, particularly shallow geothermal energy. This energy can be exploited through open and closed shallow geothermal systems (SGS), and their performances greatly depend on the ground/groundwater temperature, which can be affected by both natural and anthropogenic phenomena. The present study proposes an approach to characterize aquifers affected by high SGS exploitation (not simulated in this work). Characterization of the potential hydro/thermogeological natural state is necessary to understand the regional flow and heat transport, and to identify local thermal anomalies. Passive microseismic and groundwater monitoring were used to assess the shape and thermal status of the aquifer; numerical modeling in both steady-state and transient conditions allowed understanding of the flow and heat transport patterns. Two significant thermal anomalies were detected in a fluvio-glacial aquifer in southern Switzerland, one created by river water exfiltration and one of anthropogenic nature. A favorable time lag of 110 days between river and groundwater temperature and an urban hot plume produced by underground structures were observed. These thermal anomalies greatly affect the local thermal status of the aquifer and consequently the design and efficiency of current and future SGS. Results show that the correct characterization of the natural thermo-hydrogeological status of an aquifer is a fundamental basis for determining the impact of boundary conditions and to provide initial conditions required to perform reliable local thermal sustainability assessments, especially where high SGS exploitation occurs.

Development of thermal stability curve to forecast water column stratification

<p>Lakes are lentic environmental with unique hydrodynamic, which depends on the morphology, in and outflows, and atmospheric variables. This last driving force has its influence represented, mostly, by radiation and wind. All the interactions in the water column are harmed when the water column is divided into layers with different densities.</p><p>This condition means no gas or nutrients exchanges, impairing the food channel, and oxygen availability across the lake. Lakes and reservoirs play a key role for the development of populations, industries, human activities that need water, and also as a landscape component, this context increases the necessity to ensure its availability during the year. In this perspective, the interest in understanding lakes’ hydrodynamics and their effects on the water quality grew, aiming for appropriate management of the reservoirs and contributing areas.</p><p>To collaborate with the knowledge in this area this research intended to improve the reservoir operator’s capacity to forecast situations that can compromise their uses. This objective was achieved by investigating the possibility of a functional relationship between the atmospheric forces and the lake thermal status changing.</p><p>Stratification can be postulated as an energy balance considering the energy incident from solar radiation and the kinetic energy transferred by the wind in terms of the surface wind-drag force. The lake's thermal conditions can be affected when an instability factor is inserted in the system. The wind's speed fluctuation produces the instability that transfers an amount of energy to the water column, provoking oscillations on the isothermals or internal waves.</p><p>A curve that represents this concept was constructed by crossing high-frequency field data from four lakes from two proxies, S* Rad-1 and W* S*<sup>-1</sup>. The proxies describe the effectiveness of energy transfer from the atmospheric to the water column, and so, which is the ruling energy on balance at the moment. The variables included in it are <strong>Rad</strong> (total amount of the incident radiation on the last 24h (J m<sup>-</sup>²)); <strong>W*</strong> (mean of the wind’s speed variance in a time window (m s<sup>-1</sup>), multiplied by the air density (kg m<sup>-3</sup>) and the lake's depth (m)); and the <strong>S*</strong> (Schmidt Number mean of the last 24h (J m<sup>-</sup>²)).</p><p>The determined curve represents the thermal condition of the lake as a balanced result of the external variables and potential energy contained in the water column. This tool was able to represent the lakes’ thermal status rapidly and well, with little data information. Its performance was tested against most known lakes’ indices (Lake Number and Wedderburn Number) presenting more accurately with fewer data. Those outcomes allow an improvement to the reservoirs’ management tools and operations.</p>

Assessing the Performance Gap of Climate Change on Buildings Design Analytical Stages Using Future Weather Projections

With the higher pace of climate change, temperatures are rising each year, resulting in various effects on the thermal status of buildings. This paper takes the opportunity of analysing different scenarios of greenhouse gas (GHG) emissions using hourly weather data of future projections by implementing EPW weather files on EnergyPlus software dynamic simulations, coupled with architectural science methods of climate analysis, to test the effect of high and medium-high emission scenarios for the 2050s and 2080s future timelines on thermal comfort range, passive zones potential, and heating/cooling periods, as compared to the weather data from 2003–2017. Simulations results have shown a remarkable effect on the scale of daily cooling hours and monthly coverage under the high GHG emission scenario, expanding its range by 60 %, with 6 hours on summer peak days and 3 months/year, as well as an annual decrease in heating period by 33.3 %. Thermal comfort zones of tested periods have also witnessed an alternation, translating the effect on the passive cooling and passive heating zones’ way of variating, where the ranges are pushed towards their potential limits. Results have also demonstrated that if future weather data is not included in simulations, a weather-related performance gap is generated.

Automatic System to Control the Thermal Status of the “Orlan-ISS”-suited Cosmonaut. Main Results of Its Ground Perfection and Use for Spacewalks.

The paper represents the ISS-59/60 crew members, main tasks and results of crew training. great attention is paid to the crew activity aboard the Soyuz MS-12 manned transport vehicle (MTV) and ISS. Special attention is paid to extravehicular operations (EVA) performed according to the programs of the RS (Russian Segment) and USOS (US Orbital Segment) of the ISS. The paper also briefly analyzes the implementation of the Russian scientific applied research and experiments program.

Automatic System to Control the Thermal Status of the “Orlan-ISS”-suited Cosmonaut. Main Results of Its Ground Perfection and Use for Spacewalks.

The paper represents the ISS-59/60 crew members, main tasks and results of crew training. great attention is paid to the crew activity aboard the Soyuz MS-12 manned transport vehicle (MTV) and ISS. Special attention is paid to extravehicular operations (EVA) performed according to the programs of the RS (Russian Segment) and USOS (US Orbital Segment) of the ISS. The paper also briefly analyzes the implementation of the Russian scientific applied research and experiments program.

Modeling of Ambient Environment and Thermal Status Relationship of Pig’s Body in a Pig Barn

An experiment was conducted to evaluate the performance of temperature model (T model), relative humidity model (H model), temperature-humidity model (TH model), and temperature-humidity index model (THI model) in predicting pig’s body surface temperature (PBT). Infrared Sensor (IR) was used to measure PBT at different locations: left side (LS), right side (RS), forehead (FH) and back side (BS). Ambient environmental parameters inside the room such as temperature (ART), relative humidity (RRH) and CO2 concentration were measured using livestock environment management system (LEMS). THI model was selected as the best model in making more accurate prediction in both training (R2=0.72, RMSE=0.80, RSE=0.26 and MAPE=2.08) and validation (R2=0.74, RMSE=1.10, RSE=0.40 and MAPE=2.80) stages. For more precise modeling, apart from temperature and humidity data other environmental factors inside pig’s barn (CO2 concentration, wind speed, air pressure etc.) as well as growth factors (body weight, feed intake etc.) may be included in models.

CAS FGOALS-f3-L Model Datasets for CMIP6 GMMIP Tier-1 and Tier-3 Experiments

The Chinese Academy of Sciences (CAS) Flexible Global Ocean–Atmosphere–Land System (FGOALS-f3-L) model datasets prepared for the sixth phase of the Coupled Model Intercomparison Project (CMIP6) Global Monsoons Model Intercomparison Project (GMMIP) Tier-1 and Tier-3 experiments are introduced in this paper, and the model descriptions, experimental design and model outputs are demonstrated. There are three simulations in Tier-1, with different initial states, and five simulations in Tier-3, with different topographies or surface thermal status. Specifically, Tier-3 contains four orographic perturbation experiments that remove the Tibetan–Iranian Plateau, East African and Arabian Peninsula highlands, Sierra Madre, and Andes, and one thermal perturbation experiment that removes the surface sensible heating over the Tibetan–Iranian Plateau and surrounding regions at altitudes above 500 m. These datasets will contribute to CMIP6’s value as a benchmark to evaluate the importance of long-term and short-term trends of the sea surface temperature in monsoon circulations and precipitation, and to a better understanding of the orographic impact on the global monsoon system over highlands.