Method of fan operation control

FIELD: process engineering.

SUBSTANCE: proposed method comprises controlled air inflow. Note here that said controlled air inflow occurs between first and second stages of the fan.

EFFECT: lower power consumption.

1 dwg

 

The invention relates to ventilation units with two-stage axial fan and can find application, in particular, on the main and auxiliary fan installations, mines, mines, and other objects ventilation.

The known method of regulating the mode of operation of the mine ventilation units with two-stage axial fans to intake, artificial creation of suction air and the discharge - increased leakage. This increases the amount of air passing through the fan, and at the same time decreases its receipt in the mine (see, for example, [1], p.72, [2], p.66, 93-94). This method of control is used when the use of other known methods for any reason it is impossible or impractical.

The method allows for rapid change of the ventilation mode, but its use is associated with loss of energy, which can approximately be determined by the following formula:

where QP- an amount of drawn air, m3/s;

H0the pressure created by the installation, PA; N0=N1+H2;

H1the pressure developed in the first step;

H2the pressure developed in the second stage;

η is the efficiency of the installation.

The objective of the invention is iunie energy costs in the regulation of the ventilation unit artificial creation of air leaks.

To solve this problem on two fan units with axial fans operating on the suction side, perform the suction air flow between the first and second steps of the installation.

The essence of the proposal is illustrated in the drawing, which schematically shows a fan that implements the proposed method of regulation.

The installation includes two pressure stages 1 and 2, the supply line 3 and the drain to gate 4 for air leaks after the first stage. The first step of the installation can be either the first impeller two-stage fan unit, or the first axial fan, if the unit consists of two serially connected axial fans. The dashed line shows the drainage gate 5 when implementing the method of regulating managed unmetered air entering the first stage, as implemented in the current prototype.

Energy losses on regulationusing the proposed method can approximately be determined by the following formula:

where QP- the amount of air drawn in after the first stage, m3/s;

η1, η2accordingly the efficiency of the first and second stage.

If we take as a first approximation that η 1=η2=η, taking into account (1) and (2), reduction of energy loss in regulation in the second case (when sucking air into the second stage) can be defined by the formula:

As follows from the last formula, the energy loss in regulation using the proposed method is lower in comparison with the known method of control.

Literature

1. Borisenko HP, Borodinski A.G. and other Mining mechanics: a Textbook for high schools. - M.: Gosgortekhnadzor, 1962. - P.72.

2. Geyer VG, Tymoshenko G.M. Mine ventilation and dewatering installation: Textbook for universities. - M.: Nedra, 1987. - P.66, 93-94.

The method of regulating the operation mode of the two-stage ventilation unit with axial fan operating on a suction operated air leaks, characterized in that the conduct of air leaks between the first and second steps of the installation.



 

Same patents:

FIELD: process engineering.

SUBSTANCE: proposed device consists of vertical branch pipe 1 with its lower end accommodating air flow rate regulator that comprises two rotary valves 2 with curved reflector 3 to divide incoming air into two flows which is made from flexible material that allows to vary curvature radius and gap between aforesaid valves. Lead screw 4 serves to adjust aforesaid gap.

EFFECT: automated adjustment of incoming air flow rate and parametres.

1 dwg

FIELD: mechanics, heating.

SUBSTANCE: in compliance with the invention, the proposed method comprises the stages that follow. A tight habitable enclosure is created inside a premise, air pressure inside the said enclosure is measured and compared with preset air pressure complying with the user requirements. Given the air pressure inside the enclosure reduced below the preset value, the thruster feeding air into the enclosure is switched over to increasing pressure to previously mentioned value. Given the air pressure increasing the preset value, the thruster is switched over to reducing air pressure to preset value. Note here that, inside the space between the enclosure outer surface and the premise inner surface, an ambient air pressure is kept up. There is a set of load-carrying section elements arranged inside the premise and interjointed to make the load-carrying carcass for airtight elements to be fastened thereon to form airtight enclosure. Note that this enclosure has the sizes that prevent transmission of mechanical effects, caused by air pressure regulation inside the enclosure, from the said load-carrying carcass and other components on to the premise structural components that increase the premise reliability and life. Note also that the possibility of controlling air pressure inside the said airtight enclosure protects inhabitants against negative effects of atmospheric air pressure variation.

EFFECT: more comfortable conditions inside.

4 cl, 3 dwg

FIELD: mechanical engineering; ventilation system and devices.

SUBSTANCE: according to invention relative humidity of air in room is measured by moisture sensor arranged in chamber. Device has main inlet hole for air with adjustable passage area which is adjusted by moisture sensor. Device contains auxiliary channel made for connecting inner space of room with space outside the room and whose passage section does not depend on passage section of main inlet hole for air. Auxiliary channel is coupled through heat exchanger with chamber of moisture sensor and it can change temperature in said chamber.

EFFECT: possibility of ventilating room depending on value of relative air humidity in room.

9 cl, 3 dwg

FIELD: the mode and the arrangement are designed for increasing comfort in the building by way of maintaining it in a regulated regime of air pressure.

SUBSTANCE: the mode is in maintaining the given value of air pressure in the building. The arrangement for regulation air pressure in the building has an air propelling device with a block of air preparation, airways, valves, a sensor of exterior pressure, a sensor of inner pressure, a control block, an air intake, an air outlet, a lock chamber with an entry door and with an exit door. The turning handles of the doors are connected with shutters covering by-passing openings for leveling the air pressure.

EFFECT: increases comfort of a habitable building due to creation of controlled regime of maintaining air pressure in the building.

6 cl, 2 dwg

FIELD: apparatuses for ventilating rooms for storing fruit and vegetable products.

SUBSTANCE: ventilating apparatus includes unit for switching over poles of stator winding of three-speed induction electric motor. Said unit is mounted between program controlled device for regulating microclimate and induction motor. Air distributing ducts are arranged in opposite lateral sides of ventilated room.

EFFECT: lowered energy consumption, enlarged operational possibilities, improved operational reliability.

FIELD: control or safety systems or apparatus, particularly air flow regulation means.

SUBSTANCE: device comprises body with the first wall having curvilinear surface and valve installed in the wall and made as gate with lever and weight. Lever and weight have axes secured to body wall, which is opposite to body wall having curvilinear surface. Body walls have profiled surfaces in working valve gate area.

EFFECT: increased reliability.

4 cl, 1 dwg

The invention relates to an air conditioning system, in particular to systems of automatic control heat and humidity of the composition of the supply air

FIELD: engines and pumps.

SUBSTANCE: proposed method comprises measuring current temperature downstream of low-pressure turbine Tlp and high-pressure rotor romp Rhp, relation between said magnitudes is calculated and said relation is compared with its threshold value to generate compressor unstable operation signal if Note here that program dependence is set up to be maintained unless gas turbine compressor unstable operation signal is generated and, with ignition unit cut in, said program dependence is corrected to make lower than Rhp by 28-32%. Note also that corrected dependence is maintained unless starting is over.

EFFECT: higher reliability higher to early detection of unstable operation.

1 dwg

FIELD: machine building.

SUBSTANCE: circular flow channel (18) for turbo-machine, particularly for compressor, is arranged concentric around axis (2) of machine and is restricted with a round in cross section limiting wall (22, 24) for directing main flow (26). Limiting wall (22, 24) has multitude passes (46) of backflow distributed along circumference. Partial flow (49) is branched from the main flow (26) at point of outlet (50) and is directed back into main flow (26) at point of input (52) located downstream above point of outlet (50). Beam pens (32) of blades of a blade ring are arranged in flow channel (18). Vertexes (42) of the blade pens are placed opposite to limiting wall (22, 24) with a gap. Pens (32) of the working blades travel in specified direction (U) of rotation along circumference of limiting wall (24); or limiting wall (22) can travel in specified direction (U) of rotation relative to pins (32) of guiding blades of blade ring (41). Looked at in direction of rotation (U), point of output (50) of each pass (46) of the back flow is before corresponding point of input (52).

EFFECT: avoiding surges and stalls and increased efficiency of compressor.

17 cl, 4 dwg

FIELD: power industry.

SUBSTANCE: air-cooling apparatus control system (CS) comprises heat-transfer device with cooled medium inlet and outlet manifold, SC temperature sensor, electrically driven fans, power supply and supply frequency transducer. When all motors are operating, electric supply to each motor is provided from circuit switch. Its first input is connected to the first output of switching unit, the second one - to power supply, and the third - to the first output of frequency transducer. The first input of frequency transducer is connected to power supply, the second one - to output of temperature regulator. On its first input comes cooled medium required temperature signal, on the second one - from CS temperature sensor. On the first input of switching unit comes the signal from the second output of frequency transducer, informing about switch parametre value. If its value is maximum, signal is generated from the first output of switching unit to the first input of circuit switcher to switch the supply of the motor from frequancy transducer to constant frequency power supply. If this value is minimum the signal is generated to switch the supply of the motor to frequency transducer.

EFFECT: invention enables the usage of one frequency transducer to supply energy to a group of motors, their number in a group shall vary depending on consumed power of working fans, necessary for operating medium cooling.

3 cl, 2 dwg

FIELD: engines and pumps.

SUBSTANCE: proposed engine comprises axial-flow compressor, combustion chamber, turbine and nozzle. One, several or all compressor stages comprise vanes that feature, in plan, triangular shape and/or height equal to boundary layer thickness. Via hollow vanes of stator or compressor or blade rim, pressure is equalised over compressor stage section by bypassing air from peripheral zone of increased pressure into circum-rotor zone with lower pressure. Hollow vane peripheral parts have holes or slots arranged on front edge or vane profile concave side, while circum-rotor part has holes or slots arranged on rear edge of vane profile convex side. Compressor and/or turbine vanes feature smoothly decreasing pitch on periphery and/or circum-rotor parts on the length that corresponds to boundary layer thickness. Turbine engine has additional rim or additional stage with vanes with height equal to boundary layer thickness.

EFFECT: higher anti-surge properties, engine response and reliability.

8 cl, 3 dwg

FIELD: machine building.

SUBSTANCE: gas-turbine installation consists of two-shaft double-circuit engine with low pressure compressor and high pressure compressor separated one from another with dividing case; engine is equipped with flow divider and channel of external circuit from external side of high pressure compressor. Perforated aprons are installed at the output from the low pressure compressor between radial poles of the dividing case. The perforated aprons with the flow divider of the dividing case form an inlet section into the channel of the external circuit, while they form blind cavities from the side of the low pressure compressor with an external wall of the dividing case; at the inlet the cavities communicate with a running section of the dividing case via openings of the perforated apron, at outlets the cavities are connected with the channel of the external circuit. Valves for release of air from the channel of the external circuit into atmosphere are arranged on the external wall of the external circuit channel. Ratio of flow area of openings of the perforated apron to area of the inlet section into the channel of the external circuit equals to 0.1…2.

EFFECT: raised reliability due to uniform distribution of air flow at inlet to high pressure compressor and prevention of surge of low pressure compressor.

3 dwg

FIELD: machine building.

SUBSTANCE: stationary case has multitude of orifices for takeoff centred within range from 5% to 50% of blade chord length and with diametre smaller or equal to 30% of blade chord length. Each orifice for takeoff is tilted under two angles relative to lengthwise central axis.

EFFECT: raised efficiency and operational reliability margin.

9 cl, 1 dwg

FIELD: engines and pumps.

SUBSTANCE: invention relates to aircraft engine production and can be used in gas turbine engine (GTE) automatic control systems (ACS). Essence of invention consists in the fact that, in addition, the computing device is made in the form of space cam the first inlet of which is connected to air pressure gauge at compressor inlet, and the other one - to hydraulic cylinder of drive of inlet guide vane (IGV) blades, and outlet - to comparison device the second inlet of which is connected to outlet of air pressure gauge after compressor.

EFFECT: improving operating quality of control device, improving GTE operating reliability and aircraft safety.

1 dwg

Gas turbine plant // 2389894

FIELD: engines and pumps.

SUBSTANCE: gas turbine plant with double-flow engine includes low pressure compressor, as well as external circuit channel and high pressure compressor provided with air bypass gate valves from intermediate step to external circuit channel, which are all installed downstream. On external housing of external circuit channel above bypass gate valves there installed are air bypass valves connected at the inlet to external circuit channel, and at the outlet - to atmosphere, with possibility of their advanced or simultaneous connection with air bypass gate valves. Ratio of flow area of bypass valves to flow area of bypass gate valves is 0.8…2. Air bypass from intermediate stage of high pressure compressor to external circuit channel excludes surging of low pressure compressor.

EFFECT: improving reliability of gas turbine plant.

3 dwg

FIELD: engines and pumps.

SUBSTANCE: invention relates to aircraft engine production and can be used in gas turbine engine electronic mechanical ACS. In compliance with this invention, to identify compressor surge state, engine fan rpm is additionally analysed, as well as engine inlet temperature and pressure. In case simultaneous increase in fan rpm and engine inlet pressure and temperature and pressure drop at engine inlet and increase in air temperature at engine inlet are observed with gradient exceeding 2 to 3 times preset tolerances specified in aircraft operating performances, signal "Surge" will be generated.

EFFECT: higher engine reliability and aircraft safety.

1 dwg

FIELD: engines and pumps.

SUBSTANCE: indicator readings are taken with the help of appliance furnished with lenses. Appliance is mounted is effected by pressing coupling unit against said indicator and turning it against the stop to lock the appliance on the indicator. Appliance lens transmits the image to display. Engine started, indicator readings are read off the display simultaneously for every engine. Note that aforesaid appliance is furnished with lens coupled with the display and coupling unit consisting of piston and spring. Lower section of the appliance has a cut with ledge.

EFFECT: higher reliability and efficiency.

7 cl, 4 dwg

The invention relates to a compressor engineering, namely the multiplier centrifugal compressors with cooling gas after working speed

The invention relates to oil hydraulics and can be used in the composition of thermal control systems, as well as for cleaning gas composition of rocket technology products

The invention relates to a compressor engineering, in particular to methods for compressed air compressor unit (CU) by switching stages KU from serial to parallel mode
Up!