Power engineering and energy generating technologies

Optimum Operation of the Heat Pump in the Low-Temperature Heating Systems Using the Ground Heat

The paper under scrutiny studies optimum operation of the heat pump in low-temperature heating systems utilizing the ground heat. When using the ground heat in the heat pump heating system there is an optimal degree of cooling brine in the evaporator of the heat pump corresponding to the minimum total cost of electricity for heat pump heating system as a whole. Through experiments conducted, we determine that the optimal degree of cooling brine in the evaporator of the heat pump largely depends on the constants A complex.

Thermodynamic Efficiency of Heat Pump Systems of Air Heating

This article discusses the two most common heating systems based on air heat pumps: air heating scheme of ventilation and the so-called split-system Since the literature lacks data on sound analysis of the peculiarities of different air heating systems, their thermodynamic efficiency under different operating conditions, the article is devoted to addressing these issues. It provides an analysis of heat pump systems, air heating, the resulting values of energy utilization for such systems, given the comparative analysis of the two most common heat pump systems using heat air.

A Study of the Causes of Electric Overlapping of the Middle Phase Insulator String of the Overhead Power Line

Two possible causes of electric overlapping of the middle phase insulator string are taken into consideration: the design defect of cap-and-pin insulator and the tangent tower impact on electric field intensity near insulator string. Experimental and theoretical researches of an electric field of cap-and-pin insulator strings of 330 kV overhead power line were carried out. The insulator string's three-dimentional electric field was calculated using finite element method.

Increasing the Efficiency of Gas Turbine Plant “Aquarius” Due to the Air Cooling in Compressor

We analyze the contact air cooling application method for gas-and-steam turbine technology “Aquarius” (GSTT “Aquarius”). We utilize the real GSTT “Aquarius” characteristics (capacity 16 MW) for calculations. We demonstrate the capacity of implementing the gas turbine engine air cooling process using superheated water. Using the oversaturated water, we elaborate the air cooling process in the adapter between the compressor of low pressure and the compressor of high pressure.

The Ice Wall Usage for Heating the Buffer Zone of Buildings by Heat of Water Crystallization and Determination of its Melting Time During Thaws

The paper considers the application of the ice wall in the buffer zone of the building to reduce heat losses from the residential area while water crystallization moving in a film on the inside or outside of the watering ice surface is described. The construction does not require the periodic ice removal. Furthermore, we calculate the temperatures and other thermal characteristics under the conditions with and without watering. When the thermal resistance of heat transfer from the residential area increases, the efficiency of heat water crystallization usage rises.

The Energetic Efficiency of Heat Pump Ventilation System with Heat Recuperator and Exhausted Air Recirculation Application

This paper demonstrates the results of operation analysis of the heat pump ventilation system with a heat recuperator and exhaust air recirculation. We also obtain the coefficient value of energy application for these systems. Finally, we make some conclusion on simultaneous application of the heat pump and the exhausted air recirculation used in the ventilation systems.

Influence of Separation on Heat Transfer and Hydrodynamic of a Flat Working Surface of Heat Power Equipment

The results of an experimental study of heat transfer, friction, velocity and temperature characteristics as well as turbulence structure on the flat surface are presented for relaxation zone after a separation at free stream turbulence Tue≈0,2 % in the range of velocities 5–10 m/s. The type of a separation (laminar, transitional or turbulent) is adjusted by velocity, shape of an inlet edge of the plate and length of an interceptor, installed in the end of test section of the wind tunnel.

Burnout Investigation of Anthracite and Bituminous Coal Blends

This article examines the influence of bituminous coal to burn-out of its mixture with anthracite in the torch. Experiments were conducted at the Institute of Coal Energy Technology under the NAS of the Ukraine at the ВГП-100В facility, which models the processes in the ignition area for burners and the lower radiation part of furnace. The blends were burned with the addition of 10, 20 and 30 % of bituminous coal to anthracite of total mass and specific coals. We prove the possibility of improving the burning-out of carbon coal blends.

The Features of Voltage Control System with the Valve-Commutated Booster Transformer

The article considers the operating conditions of the valve-commutated booster transformer, intended for high-speed stepless three-phase voltage control. We show that the uncoordinated supply of control pulses determining moments of valves operation can cause the appearance of unallowable voltage or current values.

Study of the temperature field disperse polyphase system

The study considers the temperature field in the fluid bed apparatus during the granulation process. Specifically, the main regularity of its change is defined, and the new measuring technique and the obtained results processing is proposed.