The method of regulating the pressure on the discharge side in the installation of the vapor compression cycle with supercritical vapor compression (options) for their implementation

 

(57) Abstract:

Usage: in refrigeration. The inventive device with a vapor compression cycle operating at supercritical pressure on the discharge side of the schema that contains the compressor (10), a gas cooler (11), the internal heat exchanger (12), the throttle valve (13), the evaporator (14), the receiver refrigerant low pressure, is further provided with means (5) for determining at least one operating mode of the circuit, it is preferable to determine the parameter representing the temperature of the refrigerant at the exit of the gas cooler (11). 3 S. and 6 C.p. f-crystals, 3 ill.

The invention concerns a device with the steam cycle of compression, as for example, cooling and refrigeration, installation of air conditioning and heat pump installations operating in transcritical mode, and, in particular, the method of regulating the pressure on the discharge side, thereby maintaining optimum performance in relation to power consumption.

In the concurrently pending application, PCT publication NWO 90/07683, describes a device with a transcritical cycle steam compression and the method of regulation of its performance, based on the (condenser), the internal heat exchanger, the evaporator and the receiver. Capacity control is achieved by changing the cash amount of liquid in the receiver of the low pressure refrigerant is installed between the evaporator and the compressor, where between the output of the discharge side of the internal heat exchanger and the inlet of the evaporator throttle valve is used as a management tool.

Extensive tests carried out recently on the prototype device with a transcritical vapor compression, showed that for some specific applications of the present invention, for example, in mobile air conditioning systems operating under varying loads and modes, the pressure on the discharge side is smaller than at full performance, shall be governed in accordance with the valid modes (load) devices to achieve the minimum power consumption for a given performance requirement. Valid modes of operation can be determined by temperature or performance requirements. You can use any available in this area, the capacity control system as separate and independent of the activity or output. Therefore, it was necessary to develop a new strategy throttle valve for optimal performance in respect of energy consumption described device with steam compression.

Thus, the aim of the present invention is to create a new simple method and means for regulating the pressure on the discharge side in the diagram of transcritical vapor compression to achieve minimum power consumption and optimum performance of the system.

The above and other objectives of the present invention are achieved by providing a management strategy for the throttle valve in the scheme of transcritical vapor compression based on the use of specified amounts of the optimal pressure on the discharge side, conforming to the actual mode of operation of the scheme. In a preferred embodiment of the present invention the definition of modes is carried out by measuring the temperature at the outlet of the gas cooler (condenser) or beside him and the position of the valve is modulated at a given set pressure using an appropriate control system. 1

In Fig.1 graphically depicts theoretical dependence sketicism cycle vapor compression when changing the pressure on the discharge side, when standing in the evaporation temperature and the temperature coming out of the gas cooler refrigerant

In Fig. 2 is a graphical depiction of theoretical relationship between the optimal pressure on the discharge side, providing maximum ratio between cooling capacity and power on the shaft, and the temperature coming out of the gas cooler (condenser) refrigerant at three different temperatures of evaporation.

In Fig. 3 is a schematic depiction of a device with the transcritical vapor compression cycle, performed in accordance with a preferred variant of the present invention.

A well-known feature of transcritical cycles (working with the refrigerant, which is compressed to a supercritical pressure on the discharge side) is that the coefficient of performance COP, defined as the ratio of cooling capacity to the power applied to the shaft of the compressor can be increased by increasing the pressure on the discharge side, while the temperature of the refrigerant at the outlet of the gas cooler (condenser) is supported mainly constant. This can be illustrated using a standard P1-chart. However, the COP increases with increasing smeroe cooling effect is no longer fully compensated due to the additional work of compression.

Thus, for each group of actual modes of operation defined, for example, by using the evaporation temperature and the temperature of the refrigerant at the outlet of the gas cooler (condenser) can be obtained graph showing the cooling capacity (Qo), power (P) on the shaft of the compressor and their relationship (COP) depending on the pressure on the discharge side. In Fig.1 shows such a plot for the refrigerant CO2at constant temperatures of evaporation and at the exit of the gas cooler, based on calculations of theoretical cycle. When a certain pressure on the discharge side, the corresponding p' in Fig.1, the COP reaches its maximum, as shown.

By combining these results, i.e. the relevant data for the temperature of the refrigerant at the outlet of the gas cooler (condenser), the evaporation temperature and pressure on the discharge side, providing maximum COP (p') when changing modes, get a new data group, as shown in Fig.2, which can be used in the strategy of the throttle valve. By regulating the pressure on the discharge side in accordance with this schedule will always be supported maximum sootnosheniyami still appropriate, for the system to operate when the pressure at the exit or discharge, which is above the level corresponding to the maximum COP for a short period of time in order to limit the required volume of the compressor and, thus, capital expenditure and total energy expenditure. However, in the regimes of low loads, the combination of reduced pressure on the discharge side to the specified optimal level and the modulation carried out by a separate control system that will ensure a minimum consumption of energy.

Since changing the evaporation temperature has a significant impact only on the temperature of the refrigerant at the outlet of the gas cooler (condenser), it can be neglected in practice. Thus, the detected temperature of the refrigerant at the outlet of the gas cooler (condenser) or any other temperature or parameter, corresponding (for example, the temperature of cooling water, the temperature of the surrounding air, the heat load or cooling load) is the only important parameter that is required as input data for controlling the throttle valve.

The use of the regulator back pressure (suction) as the I changing the mass flow of the cooling agent and density. Butterfly valve with back pressure regulation is to maintain the outlet pressure, i.e. the pressure on the discharge side, at a predetermined value regardless of the mass flow of refrigerant and the temperature of the incoming refrigerant. Then, the control point of the back pressure regulator is controlled by an actuator operating in accordance with a given control scheme above.

Example 1. In Fig.3 depicts the preferred option transcritical refrigeration circuit containing a compressor 10, connected in series with the gas cooler 11 (condenser), the inner countercurrent heat exchanger 12 and the throttle valve 13. The evaporator 14 and the receiver 16 (receiver) liquid low pressure is connected between the throttle valve and the compressor. Temperature sensor output 5 refrigerant from the gas cooler (condenser) gives information about the modes of operation of the circuit in the control system 7, for example, in the microprocessor. The throttle valve 13 is provided by the actuator 9 and the valve position is automatically adjusted in accordance with predetermined characteristics of the set pressure by the control system.

Example 2. As shown in Fig.3, the scheme is now with the us to dispense with the microprocessor and an electronic control valve, it is shown in Fig.1. The controller is equipped with a temperature sensitive cylinder 5 mounted on or near the exit of the refrigerant from the gas cooler (condenser).

Using a membrane device, the pressure received from thermosensitive cylinder, mechanically adjusts the control point of the back pressure regulator in accordance with the temperature of the refrigerant exiting the gas cooler (condenser). Due to the regulatory efforts of the springs and of the charge in the cylinder 5 can be achieved, the corresponding relationship between the temperature and the pressure in the actual control range.

Example 3. The scheme is based on one of the concepts of the throttle valve, described in Examples 1 or 2, with the exception of the installation of temperature sensor or sensitive bulb at the outlet refrigerant from the gas cooler, the sensor or sensing bulb measures the temperature of the cooling agent which is heat. Due to the counterflow heat exchange relationship exists between the temperature coming out of the gas cooler (condenser) refrigerant and incoming cooling medium when the temperature leaving holodilnik is ambient air or cooling water.

Although the present invention has been shown and described in the drawings and in the above description of the preferred options, however, it will be obvious that there may be various changes or modifications not beyond the nature and scope of the present invention, as shown in the attached claims, as described in the attached claims. Thus, for example, any of the concepts described in Examples 1 or 2, the signal from the temperature sensor or temperature-sensitive cylinder may be replaced by a signal representing the desired cooling capacity or heating capacity of the system. Due to the correspondence between the ambient temperature and load, this signal can serve as the basis for regulation of pressure setting of the throttle valve.

1. The method of regulating the pressure on the discharge side in the installation of the vapor compression cycle with supercritical vapor compression containing successively installed in the circulation duct of the compressor, a gas cooler, an internal heat exchanger, a throttle valve, the evaporator and the receiver refrigerant low pressure, characterized in that definition is Netania in accordance with a given group of units to achieve the minimum power consumption installation with specified performance requirements.

2. The method according to p. 1, characterized in that the regulation of supercritical pressure on the discharge side is carried out by adjusting the position of the throttle valve.

3. The method of regulating the pressure on the discharge side in the installation paracorrectional cycle with sverkhkriticheskim vapor compression containing successively installed in the circulation duct of the compressor, a gas cooler, an internal heat exchanger, a throttle valve, the evaporator and the receiver refrigerant low pressure, wherein the determined at least one actual operating modes of the cycle and adjust the position of the throttle valve in accordance with a specified set of values to achieve minimum power consumption installation with specified performance requirements.

4. The method according to p. 1, or 2, or 3, characterized in that the determination of the operation modes is carried out by measuring the temperature of the refrigerant at the outlet of the gas cooler.

5. The method according to p. 1, or 2, or 3, or 4, characterized in that the cooling agent used carbon dioxide.

6. Installation of the vapor compression cycle with supercritical vapor compression, sideropenic, the throttle valve, the evaporator and the receiver refrigerant low pressure, characterized in that the installation is provided with a device for determining at least one mode of operation of the cycle and management tool that interacts with the determining device and the throttle valve to modulate supercritical pressure on the discharge side by adjusting the size of opening of the throttle valve depending on the particular mode in accordance with a given group of units of high pressure.

7. Installation according to p. 6, wherein the determining device is provided with a means for measuring the temperature of refrigerant at the outlet of the gas cooler.

8. Installation under item 6 or 7, characterized in that a throttle valve configured to regulate the back pressure variable control point, electronically controlled with a microprocessor.

9. Installation according to p. 6, characterized in that a throttle valve configured to regulate the pressure with changing the control point and provided with a thermosensitive cylinder installed at the outlet of the cooler, or near it, or in dragontrainer point in a desired ratio of the temperature of the container.

 

Same patents:

The invention relates to refrigeration and can be used to regulate the degree of filling of the evaporator refrigerant

The invention relates to refrigeration and can be used in vapor compression refrigeration systems (PHU) for various purposes to regulate the flow of liquid refrigerant in the cycle with simultaneous throttling

The flow of fluid // 2005966
The invention relates to refrigeration, and controls the flow of liquid or gas passing through the heat exchangers, mainly refrigeration units and systems

The invention relates to cryogenic equipment, in particular, to methods for the cleaning of krioagenta from impurities, and can be used in cryogenic helium and air separation devices, and in natural gas processing

The invention relates to heat engineering and can be used in transformers, heat and low-temperature heat engines

The invention relates to refrigeration, and in particular to methods and devices of absorption and diffusion refrigeration units (ADHA)

The invention relates to refrigeration and particularly to a screw compressor units intended for installation in a refrigeration machine, which are used in food, chemical industry

The invention relates to techniques for low temperature, specifically to refrigeration, and can be used in trade, food and chemical industries, transport and agriculture
The invention relates to refrigeration and can be used in gas energoholding machines and heat pumps contains the compressor and the expander, mainly, turbine or centrifugal type
The invention relates to refrigeration and can be used in gas energoholding machines and heat pumps contains the compressor and the expander, mainly, turbine or centrifugal type

Compressor // 2084774
The invention relates to techniques for the compression of gases, and more particularly to compressors for compressing refrigerant vapor and gases, with high final temperatures of the end of compression, and intended for operation in the industrial compressor units in all areas of artificial cold and compression of air and other gases

The invention relates to refrigeration, and more particularly to a method of cooling installations for their implementation and distribution to collectors of such facilities), in which different products or articles in a confined space cooled with cryogenic liquid supplied in this volume, heated, evaporated and forming gas environment in the volume of circulating paths, washer placed in the volume of products

FIELD: refrigerating engineering.

SUBSTANCE: proposed method includes setting the turbine outlet temperature and continuous measurement of pressure and temperature after air bleed stages of engine compressor. Air temperature and pressure at turbine inlet, temperature and pressure at turbine outlet and rotational speed of rotor are calculated by means of system modulating unit. Then, degree of reduction of pressure in turbine, present magnitude of corrected rotational speed of rotor and optimal magnitude of corrected rotational of rotor corresponding to maximum efficiency of turbine are determined. Braking torque of rotor is changed by acting on braking unit till optimal and present magnitudes of rotational speed of rotor get equal. In case rated magnitude of air temperature at turbine outlet exceeds preset magnitude, flow rate of purging air is decreased or increased till magnitudes get equal. When these temperatures are equal, consumption of fuel is determined for each bleed stage and is analyzed for obtaining minimum consumption of fuel. Then, air temperature and pressure at turbine inlet, temperature and pressure at turbine outlet and rotational speed of rotor are determined by means of sensors. According to results thus, obtained, above-mentioned parameters are determined and processes are repeated till optimal and present magnitudes of corrected rotational speed of turbine rotor and preset and measured magnitudes of air temperature at turbine outlet get equal after which actual consumption of fuel is determined.

EFFECT: reduced consumption of fuel.

6 cl, 1 dwg

Gas compressor // 2249727

FIELD: refrigeration industry; cooling installations components.

SUBSTANCE: the invention is dealt with the field of cooling installations equipment and may be used for production of air conditioning systems. The gas compressor contains a body and located in it two driving and two driven pistons. The body is made out of two hemispheres and contains two gaskets made out of an antifriction heat-insulating elastic-flexible material. Each piston is made in the form of ball-type sectors, on a spherical surface of each of which there is an elastic member. An aperture angle of lateral surfaces of the sectors of the driving pistons makes 86° - 90°, and an aperture angle of the lateral surfaces of the sectors of the driven pistons makes 42°-83°. A groove is made radial with trapezoidal cross-section and oriented perpendicularly to axes of the shaft of the compressor. The bases of the cross-section are in ratio of 1:2 - 1:5, and a lateral side is equal to the length of the smaller base. The elastic member is located on the bottom of each groove and its cross-section is an ellipse. The bigger diameter of the ellipse by 3-7 % is more than the length of the centerline of the trapezoidal cross-section of such a groove. On the elastic member there is the second elastic member of a rectangular cross section, the width of which by 2-5 % exceeds the length of the smaller base of the groove, and its length ensures formation of a ledge on the ball-type surface of the piston, the height of which makes 1-3 % of the smaller base of the groove. The invention allows to increase efficiency of the gas compressor.

EFFECT: the invention ensures increased efficiency of the gas compressor.

6 dwg

FIELD: refrigeration equipment, particularly using carbon-dioxide.

SUBSTANCE: compression refrigeration machine preferably using carbon-dioxide as refrigerant comprises compressor, heat exchanger, cooler (condenser), expander, liquid coolant separator linked to inlet compressor pipe by pipeline. Pipeline is provided with automatic butterfly valve maintaining constant pressure upstream butterfly valve. Machine also includes pump, connected to electric motor and linked to expander by its shaft, and evaporator. Separator has opened vapor cavity and is installed in air-tight case together with expander and liquid coolant pump. Liquid coolant pump is connected to electric motor and to expander shaft by microprocessor-operated electromagnetic clutches. Microprocessor is linked to compressor.

EFFECT: increased efficiency.

2 dwg

FIELD: wave expander-compressors, possibly used in compression systems and plants with expansion machines.

SUBSTANCE: expander-compressor includes housing in which rotor is mounted on shaft. Rotor has energy-exchange ducts communicated at rotor rotation with branch pipes for supplying and discharging gas through gas supply nozzles and diffusers for discharging gas in respective gas distributing devices. Housing is in the form of stator having electric winding. Rotor having energy-exchange ducts is provided with short-circuit winding whose rods are arranged between outer surface of rotor and its energy-exchange ducts.

EFFECT: simplified design of wave type expander-compressor.

2 dwg

FIELD: device adapted to reduce pressure in main gas pipeline, particularly for excessive gas energy utilization.

SUBSTANCE: used as electric machine is multipolar induction motor operating in generator mode and performing recovery of energy into supply main. Turbine, electric machine and velocity pickup are arranged in sealed chamber including bushing insulators connected with electric machine and velocity pickup from one side and with supply main through commutator from another side.

EFFECT: increased reliability and energy data.

2 dwg

FIELD: refrigerating and cooling, particularly continuously operating sorption machines, plants or systems.

SUBSTANCE: method involves heating mixture of cooling agent and sorption agent in boiler up to cooling agent evaporation; condensing cooling agent vapor inside condenser to form liquid cooling agent; expanding cooling agent under pressure into evaporator; absorbing the expanded cooling agent by sorption agent in absorber; storing liquid cooling agent in solution between condenser and evaporator. If cold obtaining is required valve located behind receiver in liquid flow direction is opened and liquid under increased pressure is supplied from receiver to evaporator for cold production. Valve located in front of receiver in liquid flow direction is opened only in the case when pressure at condenser outlet exceeds receiver pressure. When boiler does not generate vapor or just before stopping in vapor generation valve located behind the receiver is closed.

EFFECT: possibility to obtain cold just after device actuation.

5 cl, 2 dwg

Up!