Climate warming experiments: Design of a mesocosm heating system

Design and performance evaluation of Front glass-covered photovoltaics-thermal hybrid system for enhanced electrical output and hot water production

Distribution characteristics of particles in room with capillary radiant floor heating system

The hot waste water from the display industrial complex affects the traffic and the surrounding environment due to fog generation in the surrounding area in winter. A simulator was built to predict the occurrence of fog due to temperature changes. Humidity change was measured after setting the temperature and ambient temperature of the hot water. The evaporation rate was compared at the reservoir discharging the hot water. When the temperature was 28oC and the atmospheric temperature was -5oC, the evaporation rate rapidly saturated to 0.9 cm/day or more. It was found that the temperature difference between the water and the atmosphere in winter exceeded the fog generation criterion of 8oC, and the evaporation amount easily changed to fog. The calculated results from the relative humidity using the simulator were in good agreement with the evaporation rate. When the temperature of the hot water is cooled from 28oC to 21oC, it is confirmed that the amount of evaporation can be reduced by 33% that result in decrease of fog generation.

2 - Input—output devices

This paper describes a novel design and implementation of an automatic control system for solar hot water system in both domestic and industrial purpose. The project consists of one 150 liters evacuated tube solar collector, 300 liter storage tank, solenoid valves and an electric water heater. The objective was to implement an embedded system to control how and from which source (collector or electric heater) the hot water is been provided to the user end. The whole system is solely controlled by the controller which decides how the water should flow to the user end. The controller mainly consists of ATmega32 for central processing, LCD for displaying the level of water inside the tanks, segment displays for showing the temperature inside the tank, a regulator for setting the outlet temperature and a button for confirming the set temperature. The controller is powered by a DC power unit.

Ibe aim of this work is to study the nature of the conductivity of melts of iron chalcogenides (Fe-Se, Fe-Te, FeS-Na2S) and the conditions of its possible transformation in order to bring the high-conductivity melt to a state suitable for electrolytic decomposition into metal and chalcogen. To solve this problem, a set of methods was used - electrical conductivity (ж), thermo-EMF (a), polarization characteristics (І-V) and electrolysis (n). ж of high-conductivity melts was investigated by the four-probe method on a direct current in a quartz U-shaped cell of capillary type with graphite electrodes and molybdenum current leads in the direct current mode. The systematic error due to the accuracy class of the devices is 1%; random - does not exceed 1%. Low ж melts were studied by the two-probe AC method. Due to the high chemical aggressiveness of FeS-Na2S melts, a measuring cell with an alundum capillary was developed. Random error when measuring ж two-probe method on alternating current is 3%, systematic - is within 2%. Thermo-EMF was measured by the differential method with respect to tungsten probes. The temperature difference between the probes was recorded by a differential thermocouple. Systematic error in measuring thermo-EMF was 2%, random - 1.5%. Polarization characteristics were removed by the method of direct current in a simple cell without separation of electrode spaces. In cells of this type in an argon medium over the melt and experiments on electrolysis were performed. It is established that all samples are characterized by significant values of electrical conductivity (of the order of thousands of Sm/cm) and its negative temperature coefficients; the absolute thermo-EMF of all samples is units of цУ/deg. Melts are qualified as electron-ion (polyfunctional) conductors with a predominant metallic contribution to the conductivity. The introduction of Na2S into the FeS melt leads to a decrease in electrical conductivity and the transformation of its temperature dependence to the inherent ionic compounds. The melt electrolysis of the FeS-Na2S system with the production of iron was carried out. Thus the possibility of transformation of the nature of conductivity of highly conductive chalcogenide melts of iron towards their electrolytic ability is proved. The obtained results must be taken into account when using electrochemical technology of processing polymetallic sulfide ores, which include metal chalcogenides of iron family. KEYWORDS: MELTS, IRON CHALCOGENIDES, NATURE OF CONDUCTIVITY, ELECTRIC CONDUCTIVITY, TRANSFORMATION, ELECTROLYTIC CAPACITY.

Combined heat and power (CHP) coal-fired plants and heat-only boilers are still working as main heat sources in North China. These provide high temperature water on the primary side of district heating (DH) systems. There can be large temperature differences between the primary side and secondary side deployed in low temperature district heating (LTDH) of buildings. In this paper, a LTDH system, integrated with an organic Rankine cycle (ORC) system, is presented and evaluated on how to utilize the limited temperature difference between the primary and secondary sides in a substation. Two cases are illustrated of the performance of two modes (series or parallel connection) and energy efficiencies of the configurations with or without an ORC system. The results showed that the integrated ORC system could provide sufficient power for the circulating pumps in the DH system. The integration of the ORC leads to only a very slight decrement on the supply water temperature. Generally, the series mode can generate the maximum output power from an integrated ORC system. The parallel mode showed more flexibility on the adjustment of output power from the ORC system, especially where domestic hot water is needed. When the cold tap water was used as a cooling stream in the condenser of an ORC system before preparing to be the domestic hot water, it is very helpful in improving the performance of the ORC and increasing the energy efficiency of the DH system.

Salinity gradient solar ponds act as an integrated thermal solar energy collector and storage system. The temperature difference between the upper convective zone and the lower convective zone of a salinity gradient solar pond can be in the range of 40-60°C. The temperature at the bottom of the pond can reach up to 90°C. Low-grade heat ( < 100°C) from solar ponds is currently converted into electricity by organic Rankine cycle engines. Thermoelectric generators can operate at very low temperature differences and can be a good candidate to replace organic Rankine cycle engines for power generation from salinity gradient solar ponds. The temperature difference in a solar pond can be used to power thermoelectric generators for electricity production. This paper presents an experimental investigation of a thermoelectric generators heat exchanger system designed to be powered by the hot water from the lower convective zone of a solar pond, and cold water from the upper convective zone of a solar pond. The results obtained have indicated significant prospects of such a system to generate power from low-grade heat for remote area power supply systems.

Experimental study of a three-effect plate evaporator: seawater tests in La Spezia

Materials and design of solar heating systems for domestic hot water

Fever itself is not an illness. A fever is usually a sign that immune system is busy fighting an infection or other illness. Water is an excellent conductor, which allows it to transfer heat effectively and quickly. Water has a temperature conducting capacity twenty-seven times that of air. When Hot Water Foot Bath applied for 15-20 minutes the blood vessels in the feet starts expanding and gets improved circulation, and relieving aches, tiredness and fever. The improved blood circulation resets the hypothalamic set points by heat transfer from higher heat area to lower heat area. Objectives: To assess the effectiveness of hot water foot bath therapy on body temperature among patients with fever. Methodology: In this study, with Quantitative approach, pre-test and post-test control group design was used. This study was conducted in ICUs of Tertiary care Hospital, Ludhiana The target population consists of patients with fever admitted in ICUs. Purposive sampling technique was used to draw sample from target population as per inclusion and exclusion criteria. With lottery method, patients (N= 50) were divided into two groups i.e. n1=25 (experimental group) and n2=25 (Control group). Pre-test of body temperature was done by using standardized digital thermometer. For experimental group, hot water foot bath therapy at 107.6 °F (42°C) water temperature as measured with lotion thermometer was given for 15 minutes. Later, post-test of body temperature was done to determine the effectiveness of hot water foot bath therapy. Result: The findings of the study showed that significant difference has been found in experimental group and control group in pre-test and post-test between the groups and within experimental groups. In between the groups, i.e. in experimental group was 99.424±0.5811 and in control group was 100.648±05516. Within the experimental group, mean value of body temperature in pre-test was 100.632 ±0.4110 °F, in posttest it was 99.424 ±0.5811°F, whereas, in control group mean value of body temperature in pre-test was 100.624±0.4944°F, and in post-test it was 100.648±0.5516°F. Conclusion: The finding of the study demonstrated that hot water foot bath therapy was an effective non-Pharmacological method to reduce the body temperature. The mean post-test body temperature was lower than mean pre-test body temperature. There was significant difference in body temperature has been found between the experimental group and control group, as well as with in the experimental group in pre-test and post-test.

Open air–vapor compression refrigeration system for air conditioning and hot water cooled by cool water

The City of Monroe, Utah undertook a project to demonstrate the economic and technical viability of utilizing a low temperature geothermal resource to provide space and hot water heating to commercial, municipal, and domestic users within the community. During the course of the project, resource development and assessment, including drilling of a production well, was successfully completed. Upon completion of the field development and assessment phase of the program and of a preliminary design of the district heating system, it was determined that the project as proposed was not economically viable. This was due to: (1) a significant increase in estimated capital equipment costs resulting from the general inflation in construction costs, the large area/low population density in Monroe, and a more remote fluid disposal well site than planned, could not balance increased construction costs, (2) a lower temperature resource than predicted, and (3) due to predicted higher pumping and operating costs. After a thorough investigation of alternatives for utilizing the resource, further project activities were cancelled because the project was no longer economical and an alternative application for the resource could not be found within the constraints of the project. The City of Monroe, Utah is still seeking a beneficial use for the 600 gpm, 164/sup 0/F geothermal well. A summary of project activities included.

Utilization of biodegradable novel insulating materials for developing indigenous solar water heater for hill climates

Design of the solar water heating system for local communities in Pakistan