Increase of energy efficiency ratio of a direct evaporative cooler by dynamic behavior with energy and exergy analysis

The present research is about increasing the energy efficiency ratio (EER) in current direct evaporative coolers (DEC) in Iran. Increasing the cooling load and reducing the electrical energy consumption simultaneously (increasing the energy efficiency ratio (EER)) in DEC are the main goals of manufacturers and consumers of this device. When the circulation water pump runs continuously (static state), the circulation water rate is about 1.89 to 2.90 times of the amounts recommended in the reasonable standards. In order to adjust the circulation water rate to the recommended amount by standards, the present study has utilized repetitive cyclic scheduling programs to reduce the circulation rate to the optimal amount, (by turning the circulation pump on and off by dynamic pattern operation). In other words, the circulation pump stays on only for a certain period of a working cycle, and then the pump stays off for the rest of it. The cooling load and EER were measured based on ASHRAE 133 (2015). The results indicated that the cooling load in the dynamic state increased by 5.03 and 6.18 percent compared to the static state at low and high fan speeds, respectively. Moreover, in comparison with the static state, the amount of electrical energy consumed (kW-hr) in the dynamic state decreased by 8.8 and 4.2 percent at low and high fan speeds, respectively. Finally, the coefficient of performance (COP or EER) of the DEC in the dynamic state is increased by 15.16 and 10.78 in comparison with the static state at low and high fan speeds, respectively.

IMPROVING THE EFFICIENCY OF SYSTEMS OF LOW-POTENTIAL COMPLEX POWER STATIONS BY OPTIMAL CONTROL OF CONSUMPTION CIRCULATION WATER

Purpose. In article is organized analysis of the influence state of working circulation pump on economy of the systems low-potential complex and on the general economy of the work heat and atomic power stations. The organized analysis of the field-performance data of the systems low-potential complex Zaporozhskoy NPS in cut of the year, which has shown that as criterion to economy of the work low-potential complex can be accepted importance of the increase the production to powers of the compartment of steam turbine to power stations. Methodology. On the grounds of mathematical modeling main dependencies, which characterize efficiency of the functioning the systems low-potential complex. Results. The certain reserve energysave at increasing of efficiency of the functioning the systems low-potential complex. So total value of the losses to disposable energy in low-potential complex for energyblock HPS power 300–1200 MWt forms 7–8 % for systems of the water-supply with water-chiller and evaporation and 8–10 % for systems with radiator are determined. The organized analysis of the experimental features energyblock 300 MWt Zmievskoy HPS and is determined dependency of the pressure pair is in capacitor from the temperature circulation water and consumption pair under fixed consumption circulation water. Analytical dependencies, which allow coming from the known importance of the consumption pair, the temperature circulation water and desired pressure in capacitor to define the necessary consumption cooling water, under which will are provided given parameters are brought. Practical value. Comparative feature to energy efficiency of the functioning the system turbine-capacitor coming from features gain powers of the turbine for concrete consumption pair and dependencies of the consumption circulation water from consumed powers circulation pump will built. The broughted model of management system low-potential complex on criterion of the optimum of the consumption circulation water, under which total losses to energy will be minimum. On the grounds of afore-cited theoretical position

RANCANG BANGUN SIMULATOR SISTEM TREATMENT BAHAN BAKAR BIODISEL B20 PADA TANKI INDUK BAHAN BAKAR KRI YOS SUDARSO

Biodiesel B20 is a mixture of 80% fossil diesel fuel and 20% biofuel. When using B20, the fuel has problems in the form of jelly or mud deposition, so it needs to be overcome by treatment. The treatment that is used today uses a circulation pump but has shortcomings and is not efficient so it needs to be modified using a stirrer. In this research, an analysis of the stirrer treatment using ANSYS software simulation method was carried out to determine the change of sediment before and after stirring, with stirring speed 150 rpm. The use of a stirrer simulation is to make 2 simulation models in the main tank as the largest volume and the daily tank as the smallest volume aims to determine the differences in the results of stirring in the largest and smallest tank.. At the time of stirring, the result is a decrease in sediment from 0 minutes to 4 minutes, then 4 minutes to 8 minutes, then 8 minutes to 12 minutes, then 12 minutes to 16 minutes, then 16 minutes to 20 minutes the fuel has decreased very much and the sediment is almost gone. When stirring is carried out for 20 minutes, the sediment in the fuel tank has not reached 0% so it needs to be stirred continuously until the deposit is 0%. After the fuel has not settled, the fuel is transferred to the main engine using a transfer pump.

Exploratory Research to Improve Energy-Efficiency of a Ground-Coupled Heat Pump Utilizing an Automatic Control Device of Circulation Pump Speed

Ground-coupled heat pumps (GCHPs) are an efficient thermal energy production system that can satisfy the gap between heating and air-conditioning. Be that as it may, exploratory research on GCHPs is still lacking. The first objective of this article is to describe a utilitarian energy-efficiency improvement device for a vertical GCHP system that includes a buffer tank (BT) between the heat pump unit and the fan coil units and user supply, utilizing the quantitative regulation of water flow rate with a variable-speed circulation pump. At that point, the investigative estimations are utilized to test the performances of the GCHP system in various operating modes. Fundamental efficiency parameters (coefficient of performance (COP) and CO2 emission) are achieved for one month of running utilizing two control strategies of the GCHP—standard and optimized regulation of the water pump speed—and a benchmarking of these parameters is achieved. Exploratory research has indicated higher efficiency of the system for the flow regulation solution utilizing a BT and programmed control equipment for the circulation pump speed compared with the standard regulation solution (COPsys with 7–8% higher and CO2 emission level 7.5–8% lower). The second objective is to elaborate a simulation model of the necessary heat/cold in heating and air-conditioning periods, utilizing the Transient Systems Simulation (TRNSYS) program. Finally, the simulation, acquired utilizing the TRNSYS program, is analyzed and compared with experimental information, leading to a good agreement and, along these lines, the simulation model is approved.

Technology for producing vessel structures of the main circulation pump for BREST reactor

One of the important joints of a liquid metal fast reactor is the main circulation pump. In the course of the present research, a preproduction model of the pressure chamber, the most labor-consuming unit of the main circulation pump, was manufactured. This complex welded structure was made of 10Kh15N9S3B3 (EP-302Sh) steel sheets; fixtures and accessories were also manufactured, and as a result the metal consumption of the structure decreased. Technological documentation was made for bending, stamping of parts of the pressure chamber, welding of components, their heat and mechanic treatment, and its assembling. According to the results of this work, the existing technological documentation was adjusted in the context of the new data for pressure chamber of the main pump.