Method and device for controlling a cooling system (options), method and device control centrifugal compressor

 

(57) Abstract:

Usage: in the control system of conditioning/ cooling, adapted for use with a compressor variable speed, measuring the acceleration of the compressor and the temperature or pressure coming out of the refrigerant, which determines the rate of change of temperature or pressure of the refrigerant and reducing the acceleration of the compressor, if the rate of change of temperature or pressure of the working fluid shows the strain of the compressor. The inventive overheating of the refrigerant is maintained at the first predetermined level when the compressor operates at a constant speed, and increases to a second, higher predetermined level when the compressor is accelerated. The system is able to determine the wear of the compressor by measuring and comparing the energy supply to the compressor and the rate of change of temperature or pressure of the refrigerant in the compressor between the initial and the following periods, and to distinguish the wear of the drive components against wear creates pressure compressor parts. 8 C. and 9 C.p. f-crystals, 3 ill.

The invention relates to control systems for air conditioning systems /cooling.

is upline global warming and ozone layer depletion, fixed the exception of freons, including those used in mnogomilliardnuyu industry-conditioning/cooling.

Replacement refrigerants with more responsible environmental indicators, as R134A (replacement for R12, widely used in the automotive industry), designed for use in standard air-conditioning systems/cooling, but at the cost of significant loss of input power, capacity reduction within the specified dimensions and other shortcomings such as the incompatibility of grease.

More modern air-handling unit and air cooling, especially of the small-volume, which is typical for home and automobile air conditioners, use the discharge volume of the compressor with a relatively low pressures (e.g., 4/1). Such devices, rotating, typically at a constant speed, charge the battery or storage of highly compressed refrigerant for subsequent expansion and cooling) heat exchanger evaporator.

These systems are cyclically turned on and off to maintain pressure in the tank battery. When the reduced load cooling and requires lower flow temperatures is the fact that what energy output during start-up is significantly lower than in the permanent position of rotation; frequent cyclic recurrence during the maintenance mode can have a detrimental impact on reliability; the required changes in significant cooling due to charging and discharging of the battery; and in fact the load changes, which can be adapted to this type of work is somewhat limited.

Future improvements of this type of work can be found in newer systems, which modulate the speed of the compressor and in some cases, evaporator, and condenser fan for more even operation and improved compressed loop range and efficiency. These systems use compressors with fixed or variable displacement piston, with spiral chamber or with an oscillating plate, numerous examples of which can be found in the literature.

Describes the latest technology that uses a refrigerant with a higher specific volume than the standard liquid R12 and R22. These systems perfectly adapted to use small, high-speed centrifugal compressors require higher relations d

Typically, the modulated system, as mentioned in this patent, control the load changes and variations in the environmental conditions by the bypass valve fuel gas (very inefficient) or by changing the speed of the compressor by-pass valve of the compressor (limited range from maximum to minimum load, with lower efficiency, this optimal).

However, these and other schemes, not described here in great detail, are limited by energy consumption and range of work in the performance and optimization of characteristics that are all based on the use of pre-programmed inputs (conversion table), referring not only to the mechanical limitations of the compressor, manufacturing tolerances, mechanical conditions, operating characteristics, and limiting parameters, and thermodynamic and aerodynamic parameters of the flow of refrigerant.

The basis of the invention is to eliminate the deficiencies of the prior art:

provision of air-conditioning systems/cooling air, in which you can use environmentally friendly refrigerant without loss in efficiency compared OYA provides high efficiency over the entire load range;

ensuring management system air-conditioning/cooling, adapted for use of the compressor, for example a single-stage centrifugal compressor, two step centrifugal compressor, axial/centrifugal compressor combo or mixed flow compressor, which can be modulated in a high-speed range for areas of medium and high loads and can cyclically switched on and off for ranges of average and low loads;

the provision of a control system for air conditioning systems/cooling systems, making possible free from oscillation operation during steady state and during changes in load.

ensuring management system air-conditioning/cooling, which minimizes the acceleration of the compressor from a stop to full load;

provision of air-conditioning systems/cooling, with the possibility of using other refrigerants in the same system;

the provision of a control system for air conditioning systems/cooling systems, including proprietary diagnostic ability to identify worn and/or damaged items;

The above and other problems are solved by the present invention, adapted for use in an environmentally friendly refrigerant centrifugal compressors variable speed or another type.

The invention provides a unique control scheme to maximize efficiency throughout the load range of air conditioning systems/cooling recovery efficiency, which otherwise may be lost in the transition to suitable environmental working fluids.

The new control system of conditioning/cooling, described here, is designed to use environmentally friendly refrigerants having high specific volume, high pressure and lower absolute pressure than in conventional refrigeration systems. Low absolute pressure enable you to develop key parts made of composite materials.

The control system preferably used in the air conditioning/cooling air containing

electrically driven, hermetically sealed compressor variable speed, which can be a single stage centrifugal
induction, permanent magnet or motor with variable magnetic resistance and its associated inverter pulse-width modulation, which works not only as a power source, but also as a sensor;

electron - modulated control valve check/flow;

the condenser fan variable speed;

combination filter/wasusually/a battery to create a cycle, if necessary;

electronically include the expansion valve and

evaporator with fan variable speed.

In another aspect the invention is directed to a method of controlling a refrigeration system having a working fluid, and installed one behind the other evaporator, a centrifugal compressor variable speed, condenser and expansion valve by changing the load of the compressor.

This accelerates the rotation of the above-mentioned compressor, measure the acceleration of the above-mentioned compressor, measure the temperature or pressure of the working fluid in the above-mentioned compressor, determine the rate of change of temperature or pressure of the working fluid during any acceleration of the above-mentioned compressor, reduce the acceleration of the above-mentioned compressor, if the UE is mentioned compressor, and repeat the above operation following the operation of the acceleration of the rotation, before the termination of the acceleration of the compressor.

The acceleration of the above-mentioned compressor pre-set maximum level.

The temperature of the working fluid of the compressor is measured inside or downstream next to the said compressor.

The pressure of the working fluid of the compressor is measured inside or downstream next to the said compressor.

As the strain of the compressor may occur during and increase and decrease the speed of the compressor, the acceleration control is important in both directions. Essentially, the links here to increase or decrease acceleration refers to the absolute value of the acceleration, whereas a positive or negative acceleration can be entered.

The invention includes a device for controlling a cooling system having a working fluid and installed one behind the other evaporator, a centrifugal compressor variable speed, condenser and expansion valve, and includes a sensor for measuring the acceleration of the above-mentioned compressor, a sensor for measuring the temperature or pressure of the working fluid referred to comp the Oh of the working fluid during any period mentioned acceleration of the compressor and reduce the acceleration of the compressor, if the above-mentioned rate of change of temperature or pressure of the working fluid shows overvoltage mentioned compressor.

The invention provides a method of controlling a refrigeration system having a working fluid and installed one behind the other evaporator, a centrifugal compressor variable speed, condenser and expansion valve by changing the load of the compressor, in which the operation of the above-mentioned compressor at a constant speed, support referred to the working fluid at the first predetermined level of superheat between the said evaporator and said compressor, when the said compressor operates at a constant speed, carry out the acceleration of the rotation of the above-mentioned compressor, increase the superheat of the working fluid between the evaporator and said compressor to a second predetermined level above the first predetermined level and maintain overheating on said second predetermined level when the said compressor is accelerating, and reduce overheating of the working fluid to the first mentioned predetermined level, when the above-mentioned compressor constant returns to the Oh of the working fluid in the system, overheating of the working fluid increases during the operation of increasing the superheat of the working fluid between the evaporator and the compressor, when the compressor is returned at a constant speed by regulating the flow of the working fluid through the mentioned expansion valve.

The said evaporator includes a fan variable speed to change the speed of heat transfer of the working fluid, overheating of the working fluid increases during the operation of increasing the superheat of the working fluid between the evaporator and the compressor, when the compressor is returned at a constant speed by regulating the heat of the working fluid in said evaporator.

The invention also includes a device for controlling a cooling system having a working fluid and installed one behind the other evaporator, a centrifugal compressor variable speed, condenser and expansion valve and contains a sensor for detecting when the said compressor operates at a constant speed, microprocessor control to maintain the working fluid at the first predetermined level of overheating between these to determine when the rotation of the above-mentioned compressor is accelerating, and microprocessor control to increase the superheat of the working fluid between the evaporator and said compressor to a second predetermined level above the first predetermined level and maintain overheating on said second predetermined level when the said compressor is accelerated.

The invention also includes a method of controlling a centrifugal compressor is a variable speed refrigeration system having a working fluid by changing the flow of the working fluid, in which the acceleration of the rotation of the above-mentioned compressor during the initial period when measuring the acceleration of the above-mentioned compressor, measuring the energy supply to the said compressor and measure the rate of change of temperature or pressure of the working fluid in the above-mentioned compressor, repeat the operation for measuring the acceleration of the above-mentioned compressor to collect many of the above-mentioned measurements, carry out the storage of the above-mentioned measurement of acceleration, energy supply and the rate of change of temperature or pressure in the working fluid in said initial period, accelerate the rotation of the above-mentioned compressor next is the power to the said compressor and measure the rate of change of temperature or pressure of the working fluid in the above-mentioned compressor, determine the indication of the wear of the above-mentioned compressor by comparing the above-mentioned measurement of acceleration, energy supply and the rate of change of temperature or pressure of the working fluid in the above-mentioned following the period referred to measurements of acceleration, power and degree measure temperature or pressure of the working fluid in said initial period.

Additionally produce an operation of the alarm drive wear items mentioned compressor, if the wear indicator mentioned compressor, the power supply to the said compressor mentioned in the next period is increased by a predetermined value relative to the power supply mentioned in the initial period, when measuring the acceleration and the rate of change of temperature or pressure of the working fluid remain constant between the periods.

The method further includes an operation alarm wear creates the pressure to parts of the above-mentioned compressor, if the wear indicator mentioned compressor, the rate of change of temperature or pressure of the working fluid mentioned in the next period is reduced by a predetermined value relative to the od when the acceleration of the compressor remains constant between periods.

The said compressor is controlled electrically powered motor, said power supply on said compressor during the initial period and the next period is measured by the level of supply of electrical energy to the said motor.

Following the determination of the wear of the above mentioned compressor operation acceleration measurements, power supply and the rate of change of temperature or pressure of the working fluid during the initial period, and the sum of the measurement and storage of these measurements are repeated at a new initial period and the steps of measuring the acceleration power supply and the rate of change of temperature or pressure of the working fluid after the initial period and determine the indication of the wear of the above-mentioned compressor to determine the wear indicator mentioned compressor in the above-mentioned new initial period.

In addition, the invention includes a device for controlling a centrifugal compressor is a variable speed refrigeration system having a working fluid containing a sensor for measuring the acceleration of the above-mentioned compressor, a sensor for measuring the energy supply for providing the CSO compressor and microprocessor control to store measurements of acceleration, power supply and the rate of change of temperature or pressure of the working fluid in the initial period and an indication of wear of the above-mentioned compressor by comparing the measurements of acceleration, energy supply and the rate of change of temperature or pressure of the working fluid in the next period with the mentioned dimensions of acceleration, energy supply and the rate of change of temperature or pressure in the said initial period.

The invention also includes a method of controlling a refrigeration system having a working fluid and installed one behind the other evaporator, a centrifugal compressor variable speed, condenser and expansion valve, by changing the load of the compressor, in which the acceleration of the rotation of the above-mentioned compressor during the initial period when measuring the acceleration of the above-mentioned compressor, measuring the rate of change of the temperature or pressure of the working fluid in the above-mentioned compressor, repeat the operation speed rotation of the above-mentioned compressor in the initial period for the collection of sets of the above-mentioned measurements, carry out the storage of the above-mentioned measurements of acceleration and rate of change of the temperature or pressure of the working fluid at a specified initial period, , acceleration mentioned compressor and comparing the above-mentioned measurement of acceleration referred to in the following period with the mentioned measurements of acceleration and rate of change of the temperature or pressure of the working fluid in said initial period and reduce the acceleration of the above-mentioned compressor, if to compare acceleration mentioned in the initial period referred to the rate of change of temperature or pressure of the working fluid in the above-mentioned initial period shows the strain of the above-mentioned compressor.

The invention also provides a device for controlling a cooling system having a working fluid and installed one behind the other evaporator, a centrifugal compressor variable speed, condenser and expansion valve, containing the sensor to change the acceleration of the above-mentioned compressor, a sensor for measuring measuring the temperature or pressure of the working fluid of the above-mentioned compressor and microprocessor control to store measurements of acceleration and rate of change of the temperature or pressure of the working fluid in the initial period, comparing the measurement of acceleration referred to in the following period with the mentioned measurements of acceleration and rate of change of the temperature or pressure of the working fluid in said initial period and reduce the acceleration of the above-mentioned compressor, if to compare acceleration mentioned in the initial period referred to the rate of change of temperature or pressure of the working fluid in opiatic typical operating characteristics of the compressor, working according to a preferred variant implementation of the invention, which is useful for understanding the control options air conditioning systems/cooling, and Fig. 2 is a block diagram of the preferred options for performing system management-conditioning/cooling according to the invention; Fig. 3 is a logical diagram of one aspect of the control system according to the invention.

The control system of conditioning/cooling according to this invention is designed to combine the advantages of the efficiency of the high-pressure compressor with a single operating point, the advantages of working with variable speed for high and medium load and advantages of the system operating cycle for higher overall system efficiency for operation with low load is far from the design point. This work with a variable cycle is achieved by a unique control system.

Typical performance characteristics of the compressor shown in Fig. 1, which represents the pressure of the compressor, i.e. the output pressure of the compressor to the input pressure of the compressor (P1/P2) on the ordinate, and the flow rate of the refrigerant along the abscissa.

Plotted a safe work area, down and to the right of the line, from the unstable region of operation, that is up and to the left from line surges. Line overvoltage represents the limit of stable operation for maximum relationship of pressure compressor, at any given flow.

This chart also includes a set of lines of work in the steady state to be specially on the most effective characteristics. Features over-voltage change for different compressors and can be determined for each individual compressor is well known methods of testing. Below the line 80 over-voltage lines 82, 84 and 86 show lines of constant speed NI of the compressor, which increases in the direction shown by the arrow.

Line normal work load steady state compressor 12 is shown by the dashed line 90. The line load in the steady state imposed line 92,94, forming "Islands" of constant efficiency of the compressor, which increases in the direction shown by the arrow.

In existing air conditioning systems/cooling air line 90 normal load of the compressor is placed as determined by testing to be on Besi 80 overvoltage is during the change of speed (acceleration) of the compressor line transition load of the compressor shown in dotted lines 100 can move the compressor is operating in the unstable region over voltage over line 80 overvoltage.

In the invention, the dimension and the acceleration control is provided when the compressor increases speed and decreases when the speed as the compressor surge can occur in both directions. Compressors, even quite effective if they are designed and fitted to other components of the system, tend to have difficulties when certain conditions in the transition from stop to full load and back to stop.

The disadvantage is that the flow behind the relationship of pressures and line load transient acceleration can be swapped over voltage stability (often irreversibly) with disruption and associated risk of damaging parts. The usual practice in the past was to set the control system is an artificial limit to ensure that the speed of the compressor will never approach the line over voltage under no load combination, okruzaushuyu interval between working conditions and line overvoltage limits the achievement of the maximum cycle efficiency.

In order to avoid transitional work in the unstable region overvoltage and damage to the compressor control system of the present invention provides, in one aspect, the means for monitoring the acceleration of the compressor and the parameters of the refrigerant, as well as to control the acceleration of the compressor, if the degree of change observed state of the refrigerant shows the strain of the compressor.

Information of the type shown in Fig. 1, may be stored as a conversion table in the memory of a standard microprocessor control to determine incipient surge. However, the invention provides a system and method capable of avoiding reliance on such tables in the management of the air conditioning/cooling and put unprogrammed predetermined limits between the working conditions of the compressor and the borders of the surge.

It was found that the best way to control the system when the transition line load reaches the line voltage, is monitoring the rate of change of speed of the compressor or acceleration of the rotor of the compressor and the rate of change of temperature and/or pressure of the refrigerant in the compressor.

Measurement of the degree of change is the most rapid, available from overvoltage and effective transitions. Next, by performing a suitable device for the detection of incipient surge, such as fast-responding temperature sensors and pressure, and a suitable logic circuit of the control device of this schedule acceleration can be dynamically changed to adapt to conditions not proactive load, environmental, thermodynamic or mechanical conditions. Existing systems, as described in U.S. patent N 5065590, require an integrated bypass circuits and valves control strain, which is eliminated by this system.

The preferred embodiment of the control system described with reference to system 10 of the air conditioning/cooling, is shown in Fig.2.

The compressor 12 variable speed contains the induction motor 14 having a two-way shaft attached at one end to the centrifugal compressor 18 low pressure and centrifugal compressor 22 and high pressure opposite end.

Gaseous working fluid or refrigerant is supplied to the compressor low pressure line 32. Readily available in a fast response temperature sensors and daemen DT1/DT and DP1/DT, respectively.

Line 20 then supplies the refrigerant from the compressor 18 to the low pressure compressor 22 and high pressure. Can be used two step centrifugal compressor of the type described in U.S. patent N 5065590, the description of which is incorporated herein by reference. Depending on system parameters, obvious to experts, this two step compressor may be replaced by a compressor of any other type, such as single-stage centrifugal compressor or two step combined axial/centrifugal compressor.

For smaller applications ranging 25000-50000 BtU (British thermal unit/hour) two step centrifugal compressor can usually be related pressure DP2/DP1 in the range of 8-15 and can operate at speeds in excess of 100,000 rpm

Standard speed sensors are provided for measuring the speed NI of rotation and acceleration DN1/DT' of the shaft of the compressor. Standard inverter 16 provides for the application of a pulse of the output signal to the motor 14 variable speed. The output frequency of the inverter is regulated by pulsing signals sent from the logic circuit. Voltage V and A current of the inverter is measured standee in one important aspect of this invention, will be disclosed hereinafter in more detail.

The compressor 22 and high pressure is connected through line 24 of the refrigerant to the AC control valve 26 stop/flow. Fast-response temperature sensors and pressure is again provided to change the output temperature T2 and the output pressure P2 of the capacitor, respectively, absolute and as functions of time DT2/DT and DP2/DP, respectively.

Variable control valve stop/flow must be relatively small pressure drop in the application of relatively low pressure with environmentally friendly refrigerants. Depending on the installation of the valve 26, the refrigerant or passes through line 28 and through the valve 30 low pressure to return to the compressor 18 to the low pressure line 32 to achieve a proper balance with the flow, or leaves on the line 34 through valve 36 and high pressure line 38 to the condenser 40 or modulated in both these ways. When the refrigerant passes through the condenser 40, the fan 42 variable speed condenser (includes standard tools for measuring the speed N3 fan pulls ambient air 44 temperature TA through the condenser for cooling and reduction of refrigerant and release the on line 48 on the standard battery 50, line 52 - standard filter (wasusually 54 refrigerant), 56 - standard sight glass 58 and finally through line 60 to the valve 62 AC expansion.

The function of the valve 62 AC extension is to control the flow rate of the refrigerant to maintain the desired superheat in the refrigerant as it leaves the evaporator in the gaseous state. The invention controls the degree of overheating in a special way, which will be described below. When the refrigerant passes through line 64 to the evaporator 66, the fan 68 variable speed evaporator (includes standard tools for measuring the speed VN 2 fan pulls filed the air 70 from the environment or from internal zone to cool. After passing through the evaporator 66 cold air 72 is a zone for cooling. Gas is now the refrigerant then passes through line 74 and through the valve 30 to the low pressure line 32 back to the compressor 12.

Microprocessor controller 76 on the basis of the personal computer receives the output signals (dotted lines) on all sides of the various sensors that measure the above parameters of the system, and generates output signals (solid lines) at different mouth is one aspect of the preferred alternative implementation of the control system according to the invention shown in Fig.3. This logical system is used during operation to maintain the compressor variable speed in the safe area below the line overvoltage (see Fig.1).

The control system also provides a way to measure superheat of the refrigerant leaving the evaporator to increase work efficiency. Adjustable variables of this system are shown below and are measured at the positions shown in Fig.2.

Adjustable variables of the system:

T1 is the inlet temperature of the compressor;

T2 output temperature of the compressor;

TA is the inlet temperature of the condenser;

P1-inlet pressure of the compressor;

P2 - outlet pressure of the compressor;

N1 is the speed of the motor of the compressor;

N2 - the speed of the evaporator fan;

N3 - speed condenser fan;

CFCY - position adjustable valve stop/flow;

EXP - position of the expansion valve;

V - pulse impulse modulated voltage;

A - current motor.

The logic circuitry depicted in Fig. 3, can be programmed as a software algorithm in a standard microprocessor, which can only use one of protocolary in 1BM - compatible systems.

As shown in Fig. 3, a thermostat or similar device initially signaled a request to increase or decrease the cooling output of the system. At this time, microprocessor control checks the speed N1 of the motor of the compressor to determine whether the desired speed. The desired speed is set in advance a special performance of air conditioning systems/cooling air and can be stored in the memory mapping table.

If the speed N1 of the compressor is too small, the acceleration of rotation of the compressor DN1/DT is increased to the first speed, a predetermined operating conditions of the compressor. At the same time, the position of the EXP expansion valve is set to "closed" and the speed N2 of the evaporator fan is increased to raise the superheat of the refrigerant leaving the evaporator, which will be described in more detail below.

The rate of change of the pressure of the refrigerant at the outlet of the compressor DP2/DT is measured and checked to determine whether it is in a desirable range, indicating that the compressor is still running in a stable region below the line overvoltage. Special security and is stored in the microprocessor memory.

For example, the increased pressure of 400 PA/s can be defined within a stable work area below the line voltage, while the increased pressure of 2000 PA/c can be defined as threatening indication overvoltage. In this case, the safe range DP2/DT can be set to, say, 800 PA/s and any value that turns it will be considered spam.

As an alternative to using the rate of change of the output pressure P2 to determine the overvoltage can be used, the rate of change of the output temperature T2. Set that to prevent weak overvoltage degree of temperature change DT2/DT is a satisfactory indicator. However, to prevent a strong surge instability pressure showed their best side, and the rate of change of pressure DP2/DT is more preferable to use as an indicator.

If the value DP2/DN1/ or DT2/DN1/ is in the satisfactory range, the system checks, stable N1, i.e. work whether it's at a constant speed or is accelerating. If, on the other hand, DP2/DN1/ or DT2/DN1/ is not in a suitable range, for example, it has an excessively high value, showing what is, i.e., DN1/DT is reduced and DP2/DT/ or DT2/DN1/ is checked again whether it is in a suitable range without strain.

If DP2/DT or DT2/DN1 again too high, the acceleration decreases until, until it is in a suitable range. Once this occurs, the system again checks to determine whether big or small N1 for the desired input.

If the speed N1 of the compressor is too large, set mode negative acceleration by setting the first predetermined speed DN1/DT on the slowing down of the compressor. Found that problems with overvoltage can occur even during excessive speed deceleration of the compressor.

At the same time, the position of the EXP expansion valve is set to "closed" and the speed N2 of the evaporator fan is increased to raise the superheat of the refrigerant leaving the evaporator, DP2/DT or DT2/DT is checked to see if they are in a safe range without strain.

If so, the system continues to check stable if the speed N1 of the compressor. If DP2/DT or DT2/DT too high, DN1/DT increases (as DN1/DT is negative, this leads to a smaller absolute value of the acceleration) to the desired input.

As soon as the speed N1 of the compressor becomes desirable level requirements, i.e., DN1/DT = 0, the position of the EXP expansion valve and the speed N2 of the evaporator fan and N3 condenser fan installed (or reinstalled in the case of EXP and N2) as a function of the ambient temperature TA and the speed N1 of the compressor in accordance with the performance of the whole system.

At the same time the inlet temperature of the N1 and the input pressure P1 of the compressor is checked to determine whether to regulate the flow through the control valve stop/flow. Position CFCY valve or "open" to permit a large flow or closed to limit the flow until, until you have achieved the installation.

If desired, the input system is so small that the compressor must operate at an inefficient rate CFCY completely closed, the compressor stops working and the battery continues to supply refrigerant to the evaporator, enabling the system to shut down during periods of low demand. Thus, the control system of conditioning/cooling, described here, has the ability to work effectively required under normal conditions by changing Oresti.

Monitoring the rate of change of pressure or temperature of the refrigerant in the compressor allows the microprocessor to drive the compressor at operating conditions near the line overvoltage without an actual change in the scope of the overvoltage for any length of time, which can lead to accidents.

At extremely low load cooling the compressor is switched off by use of the control valve stop/flow with low pressure drop. This valve is closed only when the system demand falls below the level that would show unacceptable thermodynamic characteristics of the compressor.

Self-industrial sequence the ability of the acceleration control system provides significant benefits. For example, different refrigerants can be used with this compressor and control hardware for a truly different load characteristics without the need to replace or reprogram the system. For example, the basic system is designed to accommodate CFC refrigerant, such as R113, can be translated into its HFC replacement, such as HFC43-10, which has several excellent thermodynamic characterly compressor without affecting the management and/or the compressor.

Thus, various applications, which were previously considered mutually exclusive, can now work with the same basic hardware and software. A significant benefit is the use of data compressors for disparate requirements evaporator temperature, which, as a rule, require changes in management, and hardware.

Another property of this control system, air conditioning/cooling is the manner in which overheating of the refrigerant. The control system of this invention provides a method of control and change of superheat leaving the evaporator refrigerant for increased efficiency.

Last practice was based on a predetermined fixed degree of superheat of the refrigerant leaving the evaporator is supported by a variety of control schemes to ensure that no liquid enters the compressor at any load changes, hardware or surrounding conditions. Set, the maintenance of a fixed degree of overheating is inefficient in most operating conditions, as it provides more overheating than is required for safe operation, atricle control according to this invention overheating can be maintained by managing the installation of the expansion valve at a relatively low level, for example 2-5oC, only during periods of constant speed compressor, i.e. when DN1/DT = 0.

However, when the compressor is accelerated, when the speed either increases or decreases, the overheating of the refrigerant is increased to a higher predetermined level above the normal steady state. In other words, when the system detects that DN1/DT is greater than or less than 0, the expansion valve is closed to increase the amount of superheat above the normal steady state, for example, 10-15oC. When the compressor is returned to a constant operating speed, i.e., DN1/DT = 0, then the expansion valve EXP opened to reduce overheating to a smaller, predetermined level in steady state.

The desired level of superheat can be determined for a particular system without destructive experimentation. In addition to using the provisions of the EXP expansion valve for determining the degree of overheating (or its replacement) speed N2 of the evaporator fan may be increased during acceleration of the compressor, and then decrease when the compressor is returned to the constant operating speed and DN1/DT = 0.

The implementation of such a dependence is voltage, allows more efficient way of working. During operation in the steady state, the system only works with a minimum of overheating with greatly increased efficiency. With the beginning of the transition take place and necessary facilities, including modification of the relationship of the pressures of the compressor, install the expansion valve and the speed of the evaporator fan to increase the boundaries of overheating.

This invention can also be used to monitor the status of the compressor as a function of time for notification of partial defect or deterioration of the compressor, for example mechanical or aerodynamic, and to resolve system stability, until then, until the desired correction.

In this regard, the initial period is set when the rotation of the compressor is accelerated and the acceleration is measured. At the same time measured the power supply for the compressor with inverter (Y x A) and the rate of change of temperature and/or pressure of the refrigerant at the outlet of the compressor (DT2/DT or DP2/DT, respectively). Preferably a number of such measurements are done at different levels of acceleration. These acceleration measurements, power supply and the rate of change of temperature or Dora.

At any time following the initial period, performs the measurement of the energy supply to the compressor and the rate of change of temperature or pressure of the refrigerant at the outlet of the compressor during fast rotation of the compressor. These acceleration measurements of the energy supply and the rate of change of temperature or pressure of the refrigerant in the desirable next period are compared with similar measurements in the initial period.

If the power supply for the compressor in the next period increases by a significant, predetermined value, for example 5 to 10% relative to the energy supply in the initial period, when measuring the acceleration and extent of measuring the temperature of the working fluid remains constant between periods, it shows the wear of the mechanical drive compressor parts, for example, wear of the bearing or bushing. In this case, a corresponding signal that mechanical wear can be produced by the system to alert the operator.

If, on the other hand, the rate of change of temperature or pressure of the refrigerant in the next period is reduced by substantial, predetermined value, for example, on 5-10% relative to the rate of change of temperature rabaue wear aerodynamic, creating pressure compressor parts, such as compressor blades. This condition may then be signaled by the control system to the operator.

If a significant change in the comparison of the measured parameters is missing between the initial and the following periods, this can also be displayed. If any indication of wear of the compressor, the system can then be restarted so that further deterioration can be signaled to the operator.

Samakonasana the ability of this control system ensures system reliability and efficiency in that there is not only a self-diagnostic capability to indicate incipient defect, but also by the automatic restart mode speed up system allows stable operation in a degraded state until, until you made the correction.

Through the inclusion of the above sensors comparison of supplying energy with the initial and the desired "to be" acceleration is used for diagnosis of such faults, as the friction of the compressor, the performance drop due to the destruction, the breakdown of the labyrinth seal, etc.

Visiophone air conditioning/cooling. During the periods following the initial period, the compressor may accelerate during normal operation, when there is a comparison of actual acceleration with the acceleration measurements and the extent of measuring the temperature or pressure of the working fluid in the initial period, as stored in memory. If comparable acceleration in the initial period, the rate of change of temperature or pressure of the refrigerant in the initial period shows the strain of the compressor, the acceleration of the compressor can be reduced to prevent overvoltage conditions.

1. The method of controlling a cooling system having a working fluid and installed one behind the other evaporator, a centrifugal compressor variable speed, condenser and expansion valve, by changing the load of the compressor, characterized in that the speed of rotation of the above-mentioned compressor, measure the temperature or pressure of the working fluid in the above-mentioned compressor, determine the rate of change of temperature or pressure of the working fluid during any acceleration of the above-mentioned compressor, reduce the acceleration of the above-mentioned compressor, if the rate of change of temperature or pressure of the working fluid pokazaniya rotation, before the termination of the acceleration of the compressor.

2. The method according to p. 1, characterized in that the acceleration of the above-mentioned compressor pre-set maximum level.

3. The method according to p. 1, characterized in that the temperature of the working fluid of the compressor is measured inside or downstream next to the said compressor.

4. The method according to p. 1, characterized in that the pressure of the working fluid of the compressor is measured inside or downstream next to the said compressor.

5. Device for controlling a cooling system having a working fluid and installed one behind the other evaporator, a centrifugal compressor variable speed, condenser and expansion valve, characterized in that it contains a sensor for measuring the acceleration of the above-mentioned compressor, a sensor for measuring the temperature or pressure of the working fluid of the above-mentioned compressor and microprocessor control to determine the degree of change of temperature or pressure of the working fluid during any period mentioned acceleration of the compressor and reduce the acceleration of the compressor, if the rate of change of temperature or pressure of the working fluid shows perepredstavleny each other evaporator, centrifugal compressor variable speed, condenser and expansion valve by changing the load of the compressor, characterized in that the work mentioned compressor at a constant speed, support referred to the working fluid at the first predetermined level of superheat between the said evaporator and said compressor, when the said compressor operates at a constant speed, carry out the acceleration of the rotation of the above-mentioned compressor, increase the superheat of the working fluid between the evaporator and said compressor to a second predetermined level above the first predetermined level and maintain overheating on said second predetermined level when the said compressor is accelerated, and reduce overheating of the working fluid to the first mentioned predetermined level, when the above-mentioned compressor is returned to the constant working speed.

7. The method according to p. 6, characterized in that the said expansion valve to regulate flow of the working fluid in the system and in which overheating of the working fluid increases during the operation of increasing pereg the by regulating the flow of the working fluid through the mentioned expansion valve.

8. The method according to p. 6, characterized in that the said evaporator includes a fan variable speed to change the speed of heat transfer of the working fluid and in which overheating of the working fluid increases during the operation of increasing the superheat of the working fluid between the evaporator and the compressor, when the compressor is returned at a constant speed by regulating the heat of the working fluid in said evaporator.

9. Device for controlling a cooling system having a working fluid and installed one behind the other evaporator, a centrifugal compressor variable speed, condenser, and expansion valve, characterized in that it contains a sensor for detecting when the said compressor operates at a constant speed, microprocessor control to maintain the working fluid at the first predetermined level of superheat between the said evaporator and said compressor, when the said compressor operates at a constant speed, a sensor for determining when the rotation of the above-mentioned compressor is accelerated, and microprocessor control to increase the superheat of the working fluid is of a predetermined level and maintaining overheating at the above-mentioned second predetermined level, when the above-mentioned compressor is accelerated.

10. The method of controlling a centrifugal compressor is a variable speed refrigeration system having a working fluid, by changing the flow of the working fluid, characterized in that exercise the acceleration of the rotation of the above-mentioned compressor during the initial period when measuring the acceleration of the above-mentioned compressor, measuring the energy supply to the said compressor and measure the rate of change of temperature or pressure of the working fluid in the above-mentioned compressor, repeat the operation for measuring the acceleration of the above-mentioned compressor to collect many of the above-mentioned measurements, carry out the storage of the above-mentioned measurement of acceleration, energy supply and the rate of change of temperature or pressure in the working fluid in said initial period, accelerate the rotation of the above-mentioned compressor in the following referred to as the initial period when measuring the acceleration of the above-mentioned compressor, measuring the energy supply to the said compressor and measure the rate of change of temperature or pressure of the working fluid in the above-mentioned compressor, determine the indication of the wear of the above-mentioned compressor by comparing the above-mentioned measurement of the acceleration feed EN utime measurements of acceleration, power supply and the rate of change of temperature or pressure of the working fluid in said initial period.

11. The method according to p. 10, characterized in that it further perform operations on signaling of drive wear items mentioned compressor, if the wear indicator mentioned compressor for supplying energy to the said compressor mentioned in the next period is increased by a predetermined value relative to the power supply mentioned in the initial period, when measuring the acceleration and the rate of change of temperature or pressure of the working fluid remain constant between the periods.

12. The method according to p. 10, characterized in that it further includes an operation alarm wear creates the pressure to parts of the above-mentioned compressor, if the wear indicator mentioned compressor, the rate of change of temperature or pressure of the working fluid mentioned in the next period is reduced by a predetermined value relative to the rate of change of temperature or pressure in the said working fluid in said initial period, when the acceleration of the compressor remains constant between the period of the by the motor and in which said power supply on said compressor during the initial period and the next period is measured by the level of supply of electrical energy to the said motor.

14. The method according to p. 10, characterized in that, following the determination of the wear of the above mentioned compressor operation acceleration measurements, power supply and the rate of change of temperature or pressure of the fluid during the initial period, and the sum of the measurement and storage of these measurements are repeated at a new initial period and the steps of measuring the acceleration power supply and the rate of change of temperature or pressure of the working fluid after the initial period and determine the indication of the wear of the above-mentioned compressor to determine the wear indicator mentioned compressor in the above-mentioned new initial period.

15. Device for controlling a centrifugal compressor is a variable speed refrigeration system having a working fluid, characterized in that it contains a sensor for measuring the acceleration of the above-mentioned compressor, a sensor for measuring the supply of energy to the said compressor, a sensor for measuring the rate of change of the temperature or pressure of the working fluid of the above-mentioned compressor and microprocessor control to store measurements of acceleration, the energy supply to the rate of change of temperature or pressure of the working fluid in the initial period and an indication of wear is URS or pressure of the working fluid in the next period with the mentioned dimensions of acceleration, power supply and the rate of change of temperature or pressure in the said initial period.

16. The method of controlling a cooling system having a working fluid and installed one behind the other evaporator, a centrifugal compressor variable speed, condenser and expansion valve by changing the load of the compressor, characterized in that exercise the acceleration of the rotation of the above-mentioned compressor during the initial period when measuring the acceleration of the above-mentioned compressor, measuring the rate of change of the temperature or pressure of the working fluid in the above-mentioned compressor, repeat the operation speed rotation of the above-mentioned compressor in the initial period to collect many of the above-mentioned measurements, carry out the storage of the above-mentioned measurements of acceleration and rate of change of the temperature or pressure of the working fluid at a specified initial period, accelerate the rotation of the above-mentioned compressor in the following referred to as the initial period when measuring the acceleration of the above-mentioned compressor and comparing the above-mentioned measurement of acceleration referred to in the following period with the mentioned measurements of acceleration and rate of change of the temperature or pressure of the working fluid in the above-mentioned began the initial period referred to the rate of change of temperature or pressure of the working fluid in the above-mentioned initial period shows the strain of the above-mentioned compressor.

17. Device for controlling a cooling system having a working fluid and installed one behind the other evaporator, a centrifugal compressor variable speed, condenser and expansion valve, characterized in that it contains a sensor for measuring the acceleration of the above-mentioned compressor, a sensor for measuring the rate of change of the temperature or pressure of the working fluid of the above-mentioned compressor and microprocessor control to store measurements of acceleration and rate of change of the temperature or pressure of the working fluid in the initial period, comparing the measurement of acceleration referred to in the following period with the mentioned measurements of acceleration and rate of change of the temperature or pressure of the working fluid in said initial period and reduce the acceleration of the above-mentioned compressor, if to compare acceleration mentioned in the initial period, the rate of change of temperature or pressure of the working fluid in the above-mentioned initial period shows the strain of the above-mentioned compressor.

 

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FIELD: compressor station departments for natural gas transfer through gas main.

SUBSTANCE: regenerators of gas-transfer units are heated or cooled down when starting or shutting down these units, respectively, by feeding part of gas flow from operating gas-transfer units. This process is conducted until temperature in inlet gas line of regenerators is brought to cycle air temperature in inlet air line of regenerator under steady state conditions. Process rate (deg./min) is specified from condition Tex.gtr ≤ (Tex.gin - Taout) μ·ηin, where Tex.gtr is temperature of exit gases transferred in transients through inlet gas line of regenerators; Tex.gin is exit gas temperature in inlet gas line of regenerators; Taout is cycle air temperature in outlet line of regenerators under steady state conditions; μ is regeneration ratio; ηin is inherent efficiency of regenerative gas-turbine unit.

EFFECT: reduced risk of regenerator seal failure, enhanced effectiveness and reliability of compressor department in transients.

2 cl, 1 dwg

FIELD: testing of engines.

SUBSTANCE: device comprises systems for parametric, vibration, visual-optical, operating life, and expertise diagnosing of the gas-pumping assembly connected with the unit for generating list of limiting parameters of gas-pumping assembly operation. The device is additionally provided with units and subsystems for generating time schedules of the necessity of repairing the gas-pumping assembly, defect lists, orders on the replacement parts, volumes and types of the repairing materials, and calculation of cost and time of repairing..

EFFECT: enhanced accuracy of diagnosing.

1 dwg

FIELD: centrifugal compressors with air flow rate control systems; gas-turbine engines for transport facilities and gas-turbine power plants.

SUBSTANCE: proposed method is used for centrifugal compressor having impeller, radial open diffuser and radial vaned diffuser. Proposed method includes change of flow area at impeller outlet before inlet of radial vaned impeller. Besides that, flow area behind radial vaned diffuser is changed additionally; control of flow section before radial vaned diffuser and behind radial vaned diffuser is effected in turn.

EFFECT: extended field of steady operation of compressor.

3 cl, 1 dwg

FIELD: aircraft industry; compressor engineering.

SUBSTANCE: invention relates to operation of compressor system. Invention is aimed at creating device being highly sensitive and noise suppressing measuring system providing control of compressor operation modes and making it possible to control operation of compressor system taking into consideration changes of Loundary of gas-dynamic stability with wear of compressor and at action of other factor. Invention provides monitoring of compressor operation modes irrespective of changes of pressure at inlet as it uses non-dimensional parameter and provides quick determination of compressor operation mode required in practice and tracing of changes of boundary of stable operation of compressor, for instance, when its service life comes to end, and provides recording of violation of gas-dynamic stability of compressor system.

EFFECT: improved operation reliability of compressor mode monitoring system.

3 cl, 3 dwg

FIELD: aviation technology.

SUBSTANCE: analog data coming from nozzles for measuring pulsation of total and static pressures which nozzles are mounted at input and output of compressor to speed pulsation measuring unit. Simultaneously pressure pulsation is measured above blades of working wheel. Data on pulsation enters sync input and registration unit. Analog signals are introduced by means of sync input and registration unit for subsequent processing of fast-changing pressures to build isobars visualizing structure of flow in rotating working wheel during time periods corresponding to time needed for passing each interblade channel and each blade. Sizes of edge gaps are measured, angles of blades mounting are calculated, speed of flow in absolute motion at output and input of compressor is determined after measurements are completed synchronously.

EFFECT: improved precision of measurement.

2 cl, 5 dwg

FIELD: compressor plant automation; surface protection.

SUBSTANCE: proposed method includes measurement of parameter presenting dynamics of process of compressing and statistic processing of parameter basing on results of which surge presence signal is formed. According to proposed method, surge parameter is revealed using ratio of dispersion of pressure differential signal measured by flowrate meter of trubocompressor to square of its mean value, and introduction of additional surge symptom coming to determination of parameter of behaviour of pressure differential on flow rate meter of turbocompressor characterizing tendency to decrease of said pressure differential and generation of surge presence signal only when surge parameter exceeds threshold value, and parameter of behaviour of pressure differential of flowrate meter characterizing tendency of pressure differential to decrease, will be lower than its threshold value. System to reveal surge contains pressure differential sensor on flowrate meter installed in suction main line of compressor, low-pass filters, squarers, summers, delay element, divider, comparators, AND gates, trigger, switch off delay gate, and inverter.

EFFECT: improved quality of revealing of surge owing to elimination of false diagnosing, improved economic efficiency in practice.

3 cl, 2 dwg

FIELD: compressors; surge protection devices of turbocompressors.

SUBSTANCE: invention makes it possible to improve quality of diagnosing of surging, thus increasing sphere of practical application of equipment. Proposed method of diagnosing of surging is based on usage of covariation of signals from pickups whose measured parameters present surges with correlation. Used as criteria of revealing of surge is result of comparison pf parameter of surge equal to covariation of signals of measured parameter with threshold value. System to reveal surging contains compression parameters pickups 2 and 3 installed on compressor plant 1, low-pass filters 4, 5, and 9, summers 6 and 7, multiplier 8, comparator 10 and switch off delay element 11.

EFFECT: enlarged sphere of application.

9 cl, 2 dwg

Compressor // 2253758

FIELD: mechanical engineering; compressors.

SUBSTANCE: invention relates to single-stage and multistage axial and combination axial-centrifugal and axial-diagonal compressors of gas-turbine plants. Invention is aimed at enlarging range of gas-dynamic stability of compressor at preservation and increasing of level of its efficiency. Result is obtained owing to placing cylindrical or conical tubular vortex channels over blades of impellers, said channels overlap front part of blades of impellers, periphery of passage part before blades of impellers. Channels are closed at ends.

EFFECT: enlarged range of gas-dynamic stability of compressor.

7 cl, 5 dwg

FIELD: the invention refers to compressor making and designed for using at trials of pivotal, centrifugal and diagonal compressors and also their combinations.

SUBSTANCE: the objective of proposed technical solution is throttling of a compressor under consideration on a test bench. The technical result is achieved on the test bench for researching into compressors which have a drive, a multiplier, a compressor under consideration at whose input a measuring collector and still-water chamber with leveling arrangement are installed and at the output - an air collector, a throttle arrangement and output piping. At that throttle arrangement is fulfilled in the form of a part of the output piping which has a collector. At that openings are fulfilled in the collector and connected with a hollow of output piping and the collector itself is connected with an adjustable source of feeding of the working body of high pressure.

EFFECT: ensures fluent soft changing of hydraulic resistance of the output circuit and in case of necessity or an emergency situation momentary decrease of hydraulic resistance of the output circuit.

5 cl,7 dwg

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