CN104329821A

CN104329821A - Air conditioning refrigeration equipment and control method thereof

Info

Publication number: CN104329821A
Application number: CN201410332150.2A
Authority: CN
Inventors: 刘雄; 杨燕芳
Original assignee: Individual
Current assignee: Individual
Priority date: 2013-07-22
Filing date: 2014-07-04
Publication date: 2015-02-04

Abstract

The invention discloses air conditioning refrigeration equipment and a control method of the air conditioning refrigeration equipment. The air conditioning refrigeration equipment comprises a low-pressure compressor, a high-pressure compressor, a first throttling mechanism, a second throttling mechanism, a refrigerant heat exchanger, a middle heat exchanger and a heating medium heat exchanger. The outlet end of the low-pressure compressor is connected with the inlet end of the low-pressure compressor through the inlet end of the high-pressure compressor, the outlet end of the high-pressure compressor, the refrigerant side inlet end of the heating medium heat exchanger, the heating medium heat exchanger side outlet end of the heating medium heat exchanger, the second throttling mechanism, the refrigerant side inlet end of the refrigerant heat exchanger and the refrigerant side outlet end of the refrigerant heat exchanger in sequence. The inlet end of the first throttling mechanism is connected with a pipeline between the refrigerant side outlet end of the heating medium heat exchanger and the second throttling mechanism; the outlet end of the first throttling mechanism is connected with a pipeline between the outlet end of the low-pressure compressor and the inlet end of the high-pressure compressor through the refrigerant side inlet end of the middle heat exchanger and the refrigerant side outlet end of the middle heat exchanger in sequence. Simultaneous cold supply and simultaneous heat supply can be achieved, and meanwhile the heat quantity requirement and the cold quantity requirement of a user can be met at the same time.

Description

Operation of air conditioning systems and control method thereof

Technical field

The present invention relates to a kind of operation of air conditioning systems and control method thereof, belong to technical field of air conditioner refrigeration.

Background technology

Present invention applicant has delivered at " architecture science " magazine the paper that one section of name is called " the two-stage compression refrigeration heat pump cycle performance study of simultaneous air-conditioning " in June, 2011, in this paper, present invention applicant proposes a kind of two-stage compression refrigeration heat pump cycle that can realize simultaneous air-conditioning, its systematic schematic diagram as shown in Figure 5, this circulation is applicable to have for cold-peace heat demand simultaneously, and the occasion that the large refrigeration duty of thermic load is little, the cold heat demand of user can be met simultaneously, its service behaviour as shown in Figure 6, as can be seen from Figure 6: above-mentioned circulation exists a characteristic temperature in the course of the work, when environment temperature is lower than this characteristic temperature, under same operating, the service behaviour of total heat recovery circulation is greater than the performance of above-mentioned circulation (that is: the two-stage compression refrigeration heat pump cycle of the simultaneous air-conditioning proposed in above-mentioned paper), when environment temperature is greater than this characteristic temperature, under same operating, the service behaviour of total heat recovery circulation is less than the performance of above-mentioned circulation, as can be seen here, above-mentioned circulate in a part of operating condition under, the service behaviour of operation of air conditioning systems at the same time in cooling, heat supply situation can be improved further, make its service behaviour even higher than total heat recovery circulation, realize the object that operation of air conditioning systems is energy-conservation further in cooling, heat supply situation at the same time.

But it is known from above-mentioned paper, above-mentioned circulation in the course of the work must according to the needs of user, respectively independent adjustment is carried out to the cold and hot amount that operation of air conditioning systems is produced, and above-mentioned paper only gives the operation of air conditioning systems schematic diagram (as shown in Figure 5) that can realize above-mentioned circulation, and this schematic diagram can not ensure the stable operation in actual use of this operation of air conditioning systems, realize desired by operating condition, can realize to cold and hot amount according to the needs of user independently regulation and control.

Summary of the invention

The object of this invention is to provide the operation of air conditioning systems that a kind of structure is simple, reliable, can realize simultaneous air-conditioning two-stage compression refrigeration heat pump cycle, and this operation of air conditioning systems is in the course of work realizing simultaneous air-conditioning two-stage compression refrigeration heat pump cycle, can according to the needs of user, to the control method that its cold and hot amount exported regulates respectively.

In order to overcome above-mentioned technology Problems existing, the technical scheme of technical solution problem of the present invention is:

1, an operation of air conditioning systems, comprises low pressure compressor (1), high pressure compressor (2), first throttle mechanism (3), second throttle body (4), refrigerant heat exchanger (5), Intermediate Heat Exchanger (6) and heating-medium heat exchanger (7);

Described low pressure compressor (1) port of export is successively through high pressure compressor (2) arrival end, high pressure compressor (2) port of export, heating-medium heat exchanger (7) refrigerant side arrival end, heating-medium heat exchanger (7) the refrigerant side port of export, second throttle body (4) arrival end, second throttle body (4) port of export, refrigerant heat exchanger (5) refrigerant side arrival end, refrigerant heat exchanger (5) the refrigerant side port of export is connected with described low pressure compressor (1) arrival end, described first throttle mechanism (3) arrival end is connected with the pipeline between described heating-medium heat exchanger (7) the refrigerant side port of export and second throttle body (4) arrival end, and described first throttle mechanism (3) port of export is connected with the pipeline between low pressure compressor (1) port of export and high pressure compressor (2) arrival end through Intermediate Heat Exchanger (6) refrigerant side arrival end, Intermediate Heat Exchanger (6) the refrigerant side port of export successively,

It is characterized in that: this operation of air conditioning systems also comprises intermediate pressure sensor (12), cooling medium inlet temperature sensor (13), heat medium outlet temperature sensor (14) and cooling medium consumption adjusting device (15);

Described intermediate pressure sensor (12) is arranged on pipeline between described low pressure compressor (1) port of export and high pressure compressor (2) arrival end or described Intermediate Heat Exchanger (6) refrigerant side port of export pipeline, for detecting actual intermediate pressure;

Described cooling medium inlet temperature sensor (13) is arranged at described Intermediate Heat Exchanger (6) cooling medium side entrance end, for detecting cooling medium inlet temperature;

Described heat medium outlet temperature sensor (14) is arranged at described heating-medium heat exchanger (7) heating agent side outlet end, for detecting the heat medium outlet temperature of heating-medium heat exchanger (7);

Described cooling medium consumption adjusting device (15) is arranged at described Intermediate Heat Exchanger (6) cooling medium side entrance end or the port of export, for regulating the cooling medium consumption by Intermediate Heat Exchanger (6).

2, a control method for operation of air conditioning systems, described operation of air conditioning systems comprises low pressure compressor (1), high pressure compressor (2), first throttle mechanism (3), second throttle body (4), refrigerant heat exchanger (5), Intermediate Heat Exchanger (6), heating-medium heat exchanger (7), intermediate pressure sensor (12), cooling medium inlet temperature sensor (13), heat medium outlet temperature sensor (14) and cooling medium consumption adjusting device (15);

Described cooling medium consumption adjusting device (15) is arranged at described Intermediate Heat Exchanger (6) cooling medium side entrance end or the port of export, for regulating the cooling medium consumption by Intermediate Heat Exchanger (6);

It is characterized in that: described high pressure compressor (2) is frequency-changeable compressor, in the course of work, controlling intermediate pressure by the method changing high pressure compressor (2) operating frequency is desired value.

The further improvement project of scheme 2 is:

Cooling medium consumption adjusting device (15) in scheme 2 flows through the method for the cooling medium consumption of Intermediate Heat Exchanger (6) by change, control the heat medium outlet temperature of described heating-medium heat exchanger (7) for desired value.

3, a control method for operation of air conditioning systems, described operation of air conditioning systems comprises low pressure compressor (1), high pressure compressor (2), first throttle mechanism (3), second throttle body (4), refrigerant heat exchanger (5), Intermediate Heat Exchanger (6), heating-medium heat exchanger (7), intermediate pressure sensor (12), cooling medium inlet temperature sensor (13), heat medium outlet temperature sensor (14) and cooling medium consumption adjusting device (15);

It is characterized in that: described cooling medium consumption adjusting device (15) flows through the method for the cooling medium consumption of Intermediate Heat Exchanger (6) by change, the heat medium outlet temperature of described heating-medium heat exchanger (7) is controlled as desired value.

The further improvement project of scheme 3 is:

High pressure compressor (2) in scheme 3 is frequency-changeable compressor, and in the course of work, controlling intermediate pressure by the method changing high pressure compressor (2) operating frequency is desired value.

Compared with prior art, its beneficial effect is in the present invention:

1. can realize simultaneous air-conditioning, meet the cold heat demand of user simultaneously respectively;

2. can recycle the condensation heat that operation of air conditioning systems produces in running;

3. structure is simple, and reliable operation is with low cost;

4. the present invention is specially adapted to industry and civil area has cooling, heat demand simultaneously, and the occasion that the large refrigeration duty of thermic load is little.

Accompanying drawing explanation

Fig. 1 is the embodiment of the present invention 1 structural representation;

Fig. 2 is the embodiment of the present invention 3 structural representation;

Fig. 3 is the embodiment of the present invention 4 structural representation;

Fig. 4 is the embodiment of the present invention 5 structural representation;

Fig. 5 is prior art structural representation;

Fig. 6 is prior art structural representation.

Detailed description of the invention

Below in conjunction with accompanying drawing, content of the present invention is described in further detail.

Embodiment 1

Be a kind of operation of air conditioning systems that can realize simultaneous air-conditioning two-stage compression refrigeration heat pump cycle shown in Fig. 1, be applicable to industry and civil area has cooling, heat demand, and the occasion that the large refrigeration duty of thermic load is little simultaneously.

Operation of air conditioning systems shown in Fig. 1 comprises following part: low pressure compressor 1, high pressure compressor 2, first throttle mechanism 3, second throttle body 4, refrigerant heat exchanger 5, Intermediate Heat Exchanger 6, heating-medium heat exchanger 7, high pressure compressor 2 refrigerant inlet temperature sensor 11, intermediate pressure sensor 12, cooling medium inlet temperature sensor 13, heat medium outlet temperature sensor 14, cooling medium consumption adjusting device 15, outlet refrigerant temperature sensor 16, low pressure compressor 1 refrigerant inlet temperature sensor 17, low pressure compressor 1 refrigerant inlet pressure sensor 18 and controller 20.

Low pressure compressor 1, high pressure compressor 2 are the adjustable compressors of capacity, usually adopt frequency-changeable compressor;

First throttle mechanism 3, second throttle body 4 are electric expansion valve;

Refrigerant heat exchanger 5 is cold-producing medium-water-to-water heat exchangers, for the production of chilled water;

Heating-medium heat exchanger 7 is also a cold-producing medium-water-to-water heat exchanger, for the production of domestic hot-water;

Intermediate Heat Exchanger 6 is refrigerant-air heat exchangers, during work, can as evaporimeter, and absorb heat in the air of environment outdoor.

High pressure compressor 2 refrigerant inlet temperature sensor 11 is arranged on high pressure compressor 2 arrival end pipeline, for detecting high pressure compressor 2 entrance refrigerant temperature.

Intermediate pressure sensor 12 is arranged on the pipeline between low pressure compressor 1 port of export and high pressure compressor 2 arrival end, or on Intermediate Heat Exchanger 6 refrigerant side port of export pipeline, for detecting actual intermediate pressure.

Cooling medium inlet temperature sensor 13 is arranged at Intermediate Heat Exchanger 6 cooling medium side entrance end, for detecting cooling medium inlet temperature; In the scheme shown in the present embodiment Fig. 1, what adopt due to cooling medium is outdoor air, therefore during work, cooling medium inlet temperature sensor 13 detects is the inlet air temp of Intermediate Heat Exchanger 6 air side.

Heat medium outlet temperature sensor 14 is arranged at heating-medium heat exchanger 7 heating agent side outlet end, for detecting the heat medium outlet temperature of heating-medium heat exchanger 7; In the scheme shown in the present embodiment Fig. 1, because heating-medium heat exchanger 7 is for the production of domestic hot-water, therefore during work, domestic hot-water's outlet temperature of what heat medium outlet temperature sensor 14 detected is heating-medium heat exchanger 7.

Cooling medium consumption adjusting device 15 is arranged at Intermediate Heat Exchanger 6 cooling medium side entrance end or the port of export, for regulating the cooling medium consumption by Intermediate Heat Exchanger 6; In the scheme shown in the present embodiment Fig. 1, what adopt due to cooling medium is outdoor air, therefore cooling medium consumption adjusting device 15 blower fan that to be rotating speeds adjustable, usually adopt frequency conversion fan; During work, by changing the frequency of blower motor, the rotating speed of blower fan is regulated and controled, thus change the air mass flow by Intermediate Heat Exchanger 6.Specifically, when the frequency of blower motor raises, then the rotating speed of blower fan increases, and is increased by the air mass flow of Intermediate Heat Exchanger 6; When the frequency of blower motor reduces, then the rotating speed of blower fan reduces, and is reduced by the air mass flow of Intermediate Heat Exchanger 6.

Outlet refrigerant temperature sensor 16 is arranged at the refrigerant heat exchanger 5 medium side port of export, for detecting the outlet temperature of refrigerant; In the scheme shown in the present embodiment Fig. 1, because refrigerant heat exchanger 5 is for the production of chilled water, therefore during work, the chilled water outlet temperature of what outlet refrigerant temperature sensor 16 detected is refrigerant heat exchanger 5.

Low pressure compressor 1 refrigerant inlet temperature sensor 17 is arranged on low pressure compressor 1 arrival end pipeline, for detecting low pressure compressor 1 entrance refrigerant temperature.

Low pressure compressor 1 refrigerant inlet pressure sensor 18 is also arranged on low pressure compressor 1 arrival end pipeline, for detecting low pressure compressor 1 entrance refrigerant pressure.

In the course of work, controller 20 is for the control to operation of air conditioning systems, and the cold and hot amount to operation of air conditioning systems is produced that needs according to user regulates and controls, and usually adopts PLC, such as: siemens PLC.

In operation of air conditioning systems shown in Fig. 1, the connected mode of the refrigeration heat pump system be made up of low pressure compressor 1, high pressure compressor 2, first throttle mechanism 3, second throttle body 4, refrigerant heat exchanger 5, Intermediate Heat Exchanger 6 and heating-medium heat exchanger 7 is as described below:

Low pressure compressor 1 port of export through high pressure compressor 2 arrival end, high pressure compressor 2 port of export, heating-medium heat exchanger 7 refrigerant side arrival end, the heating-medium heat exchanger 7 refrigerant side port of export, second throttle body 4 arrival end, second throttle body 4 port of export, refrigerant heat exchanger 5 refrigerant side arrival end, the refrigerant heat exchanger 5 refrigerant side port of export, is connected with low pressure compressor 1 arrival end successively; First throttle mechanism 3 arrival end is connected with the pipeline between the heating-medium heat exchanger 7 refrigerant side port of export and second throttle body 4 arrival end, first throttle mechanism 3 port of export through Intermediate Heat Exchanger 6 refrigerant side arrival end, the Intermediate Heat Exchanger 6 refrigerant side port of export, is connected with the pipeline between low pressure compressor 1 port of export and high pressure compressor 2 arrival end successively.

Above-mentioned refrigeration heat pump system workflow is operationally as follows: the refrigerant superheat steam of HTHP is after the discharge of high pressure compressor 2 port of export, enter heating-medium heat exchanger 7 refrigerant side and water carries out indirect heat exchange, heating domestic hot water, refrigerant vapour becomes refrigerant liquid after releasing heat, from heating-medium heat exchanger 7, be out divided into two-way afterwards; First via refrigerant liquid is after second throttle body 4 throttling, the gas-fluid two-phase mixture becoming low-temp low-pressure enters refrigerant heat exchanger 5 refrigerant side, heat exchange is carried out with water in refrigerant heat exchanger 5, produce chilled water, after refrigerant air-liquid two-phase mixture absorbs heat, become the refrigerant gas of low-temp low-pressure, enter the refrigerant superheat steam that low pressure compressor 1 is compressed into medium temperature and medium pressure, then enter high pressure compressor 2 arrival end pipeline; Second road refrigerant liquid is after first throttle mechanism 3 throttling, become the gas-fluid two-phase mixture of medium temperature and medium pressure, enter Intermediate Heat Exchanger 6 refrigerant side, heat exchange is carried out with air in Intermediate Heat Exchanger 6, from air, absorb heat, after the refrigerant air-liquid two-phase mixture absorption heat of medium temperature and medium pressure, become the refrigerant gas of medium temperature and medium pressure, from Intermediate Heat Exchanger 6 out after, also enter high pressure compressor 2 arrival end pipeline; The cold-producing medium of pressing in two-way, after the mixing of high pressure compressor 2 arrival end pipeline, enters high pressure compressor 2 and is re-compressed, so far complete the two-stage compression refrigeration heat pump cycle of a simultaneous air-conditioning.

In the course of work, low pressure compressor 1 adopts the method changing operating frequency, controls the outlet refrigerant temperature of refrigerant heat exchanger 5; In the scheme shown in the present embodiment Fig. 1, because refrigerant heat exchanger 5 is for the production of chilled water, therefore during work, low pressure compressor 1 adopts the method changing operating frequency, controls the chilled water outlet temperature of refrigerant heat exchanger 5.

Concrete control method is as follows: during work, the chilled water that outlet refrigerant temperature sensor 16 detects actual outlet water temperature, be fed to controller 20, in controller 20, compare with the chilled water outlet water temperature desired value preset, when chilled water actual outlet water temperature is greater than chilled water outlet water temperature desired value and exceedes requirement difference, then improve the operating frequency of low pressure compressor 1; When chilled water actual outlet water temperature is less than chilled water outlet water temperature desired value and exceedes requirement difference, then reduce the operating frequency of low pressure compressor 1; When the deviate of chilled water actual outlet water temperature and chilled water outlet water temperature desired value is in the scope required, then the operating frequency of maintenance low pressure compressor 1 is constant.The deviate of above-mentioned chilled water actual outlet water temperature and chilled water outlet water temperature desired value is all set in controller 20 in advance.

During work, second throttle body 4 adopts the method changing valve opening, exports refrigerant superheat degree control low pressure compressor 1 entrance refrigerant superheat degree or refrigerant heat exchanger 5.In scheme described in all embodiments of the present invention, if do not consider the overheated of low pressure compressor 1 suction line, low pressure compressor 1 entrance refrigerant superheat degree equals refrigerant heat exchanger 5 and exports refrigerant superheat degree, therefore the control to low pressure compressor 1 entrance refrigerant superheat degree, also can think control refrigerant heat exchanger 5 being exported to refrigerant superheat degree.As follows to the concrete control method of low pressure compressor 1 entrance refrigerant superheat degree.

Method one: during work, low pressure compressor 1 refrigerant inlet temperature sensor 17, the low pressure compressor 1 refrigerant inlet actual temperature that low pressure compressor 1 refrigerant inlet pressure sensor 18 detects and pressure data, be fed to controller 20, according to these two data in controller 20, calculate the actual degree of superheat of low pressure compressor 1 entrance cold-producing medium, and compare with the low pressure compressor 1 entrance refrigerant superheat degree desired value that presets in controller 20, when the actual degree of superheat of low pressure compressor 1 entrance cold-producing medium is greater than low pressure compressor 1 entrance refrigerant superheat degree desired value, and when exceeding requirement difference, then increase the valve opening of second throttle body 4, when the actual degree of superheat of low pressure compressor 1 entrance cold-producing medium is less than low pressure compressor 1 entrance refrigerant superheat degree desired value and exceedes requirement difference, then reduce the valve opening of second throttle body 4, when the actual degree of superheat of low pressure compressor 1 entrance cold-producing medium and the deviate of low pressure compressor 1 entrance refrigerant superheat degree desired value are in the scope required, then the valve opening maintaining second throttle body 4 is constant.

Method two: a refrigerant heat exchanger 5 refrigerant inlet temperature sensor is set again at second throttle body 4 port of export, for detecting the cold-producing medium actual entry temperature of refrigerant heat exchanger 5, low pressure compressor 1 refrigerant inlet temperature sensor 17 is utilized to detect the refrigerant inlet actual temperature of low pressure compressor 1 in addition, these two temperatures data are fed to controller 20, according to these two temperature datas in controller 20, calculate the actual degree of superheat of low pressure compressor 1 entrance cold-producing medium, and compare with the low pressure compressor 1 entrance refrigerant superheat degree desired value that presets in controller 20, when the actual degree of superheat of low pressure compressor 1 entrance cold-producing medium is greater than low pressure compressor 1 entrance refrigerant superheat degree desired value, and when exceeding requirement difference, then increase the valve opening of second throttle body 4, when the actual degree of superheat of low pressure compressor 1 entrance cold-producing medium is less than low pressure compressor 1 entrance refrigerant superheat degree desired value and exceedes requirement difference, then reduce the valve opening of second throttle body 4, when the actual degree of superheat of low pressure compressor 1 entrance cold-producing medium and the deviate of low pressure compressor 1 entrance refrigerant superheat degree desired value are in the scope required, then the valve opening maintaining second throttle body 4 is constant.The actual degree of superheat of above-mentioned low pressure compressor 1 entrance cold-producing medium and the deviate of low pressure compressor 1 entrance refrigerant superheat degree desired value are all set in controller 20 in advance.

It must be noted that: the above-described control method to low pressure compressor 1 entrance refrigerant superheat degree is also applicable to export refrigerant heat exchanger 5 control of refrigerant superheat degree.

During work, first throttle mechanism 3 use in the present invention has four kinds of schemes, as described below respectively.

First scheme

First throttle mechanism 3 adopts the method changing valve opening, controls high pressure compressor 2 entrance refrigerant superheat degree.Under this scheme, there are again two kinds of concrete control methods in first throttle mechanism 3, as described below.

Method one:

During work, high pressure compressor 2 refrigerant inlet temperature sensor 11, the high pressure compressor 2 refrigerant inlet actual temperature that intermediate pressure sensor 12 detects and pressure data, be fed to controller 20, according to these two data in controller 20, (that is: the actual degree of superheat of high pressure compressor 2 entrance cold-producing medium equals high pressure compressor 2 refrigerant inlet actual temperature that refrigerant inlet temperature sensor 11 detects and deducts the cold-producing medium saturation temperature corresponding to intermediate pressure that intermediate pressure sensor 12 detects to calculate the actual degree of superheat of high pressure compressor 2 entrance cold-producing medium.), and compare with the high pressure compressor 2 entrance refrigerant superheat degree desired value that presets in controller 20, when the actual degree of superheat of high pressure compressor 2 entrance cold-producing medium is greater than high pressure compressor 2 entrance refrigerant superheat degree desired value and exceedes requirement difference, then increase the valve opening of first throttle mechanism 3; When the actual degree of superheat of high pressure compressor 2 entrance cold-producing medium is less than high pressure compressor 2 entrance refrigerant superheat degree desired value and exceedes requirement difference, then reduce the valve opening of first throttle mechanism 3; When the actual degree of superheat of high pressure compressor 2 entrance cold-producing medium and the deviate of high pressure compressor 2 entrance refrigerant superheat degree desired value are in the scope required, then the valve opening maintaining first throttle mechanism 3 is constant.

Method two:

At first throttle mechanism 3 port of export, an Intermediate Heat Exchanger 6 refrigerant inlet temperature sensor is set again, for detecting the cold-producing medium actual entry temperature of Intermediate Heat Exchanger 6, high pressure compressor 2 refrigerant inlet temperature sensor 11 is utilized to detect the refrigerant inlet actual temperature of high pressure compressor 2 in addition, these two temperatures data are fed to controller 20, according to these two temperature datas in controller 20, (that is: the refrigerant inlet actual temperature that the actual degree of superheat of high pressure compressor 2 entrance cold-producing medium equals the high pressure compressor 2 that refrigerant inlet temperature sensor 11 detects deducts the Intermediate Heat Exchanger 6 cold-producing medium actual entry temperature that Intermediate Heat Exchanger 6 refrigerant inlet temperature sensor detects to calculate the actual degree of superheat of high pressure compressor 2 entrance cold-producing medium.), and compare with the high pressure compressor 2 entrance refrigerant superheat degree desired value that presets in controller 20, when the actual degree of superheat of high pressure compressor 2 entrance cold-producing medium is greater than high pressure compressor 2 entrance refrigerant superheat degree desired value and exceedes requirement difference, then increase the valve opening of first throttle mechanism 3; When the actual degree of superheat of high pressure compressor 2 entrance cold-producing medium is less than high pressure compressor 2 entrance refrigerant superheat degree desired value and exceedes requirement difference, then reduce the valve opening of first throttle mechanism 3; When the actual degree of superheat of high pressure compressor 2 entrance cold-producing medium and the deviate of high pressure compressor 2 entrance refrigerant superheat degree desired value are in the scope required, then the valve opening maintaining first throttle mechanism 3 is constant.

The actual degree of superheat of above-mentioned high pressure compressor 2 entrance refrigerant superheat degree desired value, high pressure compressor 2 entrance cold-producing medium and the deviate of high pressure compressor 2 entrance refrigerant superheat degree desired value are all set in controller 20 in advance.

When practical application, high pressure compressor 2 entrance refrigerant superheat degree desired value is set to the temperature approach expected exceeded than the cold-producing medium saturation temperature corresponding to intermediate pressure desired value usually.The temperature approach of this expectation can be a fixed value, also can be a changing value.

During work, above-described intermediate pressure desired value depends on the cooling medium inlet temperature that cooling medium inlet temperature sensor 13 detects.Usually, the cold-producing medium saturation temperature corresponding to intermediate pressure desired value can be set equal to the cooling medium inlet temperature that cooling medium inlet temperature sensor 13 detects and deduct a heat transfer temperature difference expected.Hereinafter more detailed description is had about intermediate pressure desired value is of the present invention.

Alternative plan

First throttle mechanism 3 adopts the method changing valve opening, exports refrigerant discharge temperature control high pressure compressor 2.

Now, a refrigerant discharge temperature sensor should be set again on high pressure compressor 2 port of export pipeline, actual refrigerant discharge temperature is exported for detecting high pressure compressor 2, during work, this temperature data is fed to controller 20, export refrigerant discharge temperature desired value with the high pressure compressor 2 preset in controller 20 to compare, when high pressure compressor 2 export actual refrigerant discharge temperature be greater than high pressure compressor 2 export refrigerant discharge temperature desired value and exceed requirement difference time, then increase the valve opening of first throttle mechanism 3; When high pressure compressor 2 export actual refrigerant discharge temperature be less than high pressure compressor 2 export refrigerant discharge temperature desired value and exceed requirement difference time, then reduce the valve opening of first throttle mechanism 3; When high pressure compressor 2 exports deviate that actual refrigerant discharge temperature and high pressure compressor 2 export refrigerant discharge temperature desired value in the scope required, then the valve opening of maintenance first throttle mechanism 3 is constant.

The deviate that the refrigerant discharge temperature that above-mentioned high pressure compressor 2 exports refrigerant discharge temperature desired value, high pressure compressor 2 exports reality and high pressure compressor 2 export refrigerant discharge temperature desired value is all set in controller 20 in advance.

The delivery temperature desired value that high pressure compressor 2 exports cold-producing medium is usually closely related with the lubricating oil used, and is generally no more than 130 DEG C.

Third program

First throttle mechanism 3 adopts the method changing valve opening, controls high pressure compressor 2 entrance refrigerant temperature.Concrete control method is as described below.

During work, the high pressure compressor 2 refrigerant inlet actual temperature data that high pressure compressor 2 refrigerant inlet temperature sensor 11 detects, be fed to controller 20, compare with the high pressure compressor 2 entrance refrigerant temperature desired value that presets in controller 20 in controller 20, when the actual temperature of high pressure compressor 2 entrance cold-producing medium is greater than high pressure compressor 2 entrance refrigerant temperature desired value and exceedes requirement difference, then increase the valve opening of first throttle mechanism 3; When the actual temperature of high pressure compressor 2 entrance cold-producing medium is less than high pressure compressor 2 entrance refrigerant temperature desired value and exceedes requirement difference, then reduce the valve opening of first throttle mechanism 3; When the actual temperature of high pressure compressor 2 entrance cold-producing medium and the deviate of high pressure compressor 2 entrance refrigerant temperature desired value are in the scope required, then the valve opening maintaining first throttle mechanism 3 is constant.

The actual temperature of above-mentioned high pressure compressor 2 entrance refrigerant temperature desired value, high pressure compressor 2 entrance cold-producing medium and the deviate of high pressure compressor 2 entrance refrigerant temperature desired value are all set in controller 20 in advance.

When practical application, the high pressure compressor 2 entrance refrigerant temperature desired value cold-producing medium saturation temperature be usually set equal to corresponding to intermediate pressure desired value adds a temperature approach expected.The temperature approach of this expectation can be a fixed value, also can be a changing value.

During work, above-described intermediate pressure desired value depends on the cooling medium inlet temperature that cooling medium inlet temperature sensor 13 detects equally.Usually, the cold-producing medium saturation temperature corresponding to intermediate pressure desired value can be set equal to the cooling medium inlet temperature that cooling medium inlet temperature sensor 13 detects and deduct a heat transfer temperature difference expected.Hereinafter more detailed description is had about intermediate pressure desired value is of the present invention.

Fourth program

First throttle mechanism 3 adopts the method changing valve opening, controls the refrigerant superheat degree of the Intermediate Heat Exchanger 6 refrigerant side port of export; Its concrete control method is as described below.

An Intermediate Heat Exchanger 6 refrigerant side discharge-end temperature sensor is set up again, the actual outlet temperature of the cold-producing medium for detecting Intermediate Heat Exchanger 6 at the Intermediate Heat Exchanger 6 refrigerant side port of export.During work, Intermediate Heat Exchanger 6 refrigerant side discharge-end temperature sensor, the actual temperature of the Intermediate Heat Exchanger 6 refrigerant side port of export that intermediate pressure sensor 12 detects and pressure data, be fed to controller 20, according to these two data in controller 20, (that is: the actual outlet temperature of cold-producing medium that the actual degree of superheat of cold-producing medium of the Intermediate Heat Exchanger 6 refrigerant side port of export equals the Intermediate Heat Exchanger 6 that Intermediate Heat Exchanger 6 refrigerant side discharge-end temperature sensor detects deducts the cold-producing medium saturation temperature corresponding to intermediate pressure that intermediate pressure sensor 12 detects to calculate the actual degree of superheat of cold-producing medium of the Intermediate Heat Exchanger 6 refrigerant side port of export.), and compare with the refrigerant superheat degree desired value of the Intermediate Heat Exchanger 6 refrigerant side port of export that presets in controller 20, when the actual degree of superheat of cold-producing medium of the Intermediate Heat Exchanger 6 refrigerant side port of export is greater than the refrigerant superheat degree desired value of the Intermediate Heat Exchanger 6 refrigerant side port of export and exceedes requirement difference, then increase the valve opening of first throttle mechanism 3; When the actual degree of superheat of cold-producing medium of the Intermediate Heat Exchanger 6 refrigerant side port of export is less than the refrigerant superheat degree desired value of the Intermediate Heat Exchanger 6 refrigerant side port of export and exceedes requirement difference, then reduce the valve opening of first throttle mechanism 3; When the deviate of the actual degree of superheat of cold-producing medium of the Intermediate Heat Exchanger 6 refrigerant side port of export and the refrigerant superheat degree desired value of the Intermediate Heat Exchanger 6 refrigerant side port of export is in the scope required, then the valve opening maintaining first throttle mechanism 3 is constant.

The deviate of the refrigerant superheat degree desired value of the refrigerant superheat degree desired value of the above-mentioned Intermediate Heat Exchanger 6 refrigerant side port of export, the actual degree of superheat of cold-producing medium of the Intermediate Heat Exchanger 6 refrigerant side port of export and the Intermediate Heat Exchanger 6 refrigerant side port of export is all set in controller 20 in advance.

The refrigerant superheat degree desired value of the above-mentioned Intermediate Heat Exchanger 6 refrigerant side port of export can be a fixed value, also can be a changing value.

First throttle mechanism 3 above-mentioned four kinds of operational versions in the present invention, during work, can individually use, also can conbined usage.

Concrete using method is: when using first scheme, and namely first throttle mechanism 3 adopts the method changing valve opening, when controlling high pressure compressor 2 entrance refrigerant superheat degree, detects high pressure compressor 2 simultaneously and exports actual refrigerant discharge temperature; Be greater than high pressure compressor 2 export refrigerant discharge temperature desired value when high pressure compressor 2 exports actual refrigerant discharge temperature, and when exceeding requirement difference, then abandon first scheme, (that is: first throttle mechanism 3 adopts the method changing valve opening to use alternative plan, export refrigerant discharge temperature to high pressure compressor 2 to control), by increasing the valve opening of first throttle mechanism 3; Make high pressure compressor 2 export actual refrigerant discharge temperature to reduce, detect the actual degree of superheat of high pressure compressor 2 entrance cold-producing medium simultaneously; Export refrigerant discharge temperature desired value lower than high pressure compressor 2 when high pressure compressor 2 exports actual refrigerant discharge temperature and exceed requirement difference, when the actual degree of superheat of high pressure compressor 2 entrance cold-producing medium and the deviation of high pressure compressor 2 entrance refrigerant superheat degree desired value are no more than the difference of requirement simultaneously, then abandon alternative plan, reuse first scheme.

Similar, when using third program, namely first throttle mechanism 3 adopts the method changing valve opening, when controlling high pressure compressor 2 entrance refrigerant temperature, detects high pressure compressor 2 simultaneously and exports actual refrigerant discharge temperature; Be greater than high pressure compressor 2 export refrigerant discharge temperature desired value when high pressure compressor 2 exports actual refrigerant discharge temperature, and when exceeding requirement difference, then abandon third program, (that is: first throttle mechanism 3 adopts the method changing valve opening to use alternative plan, export refrigerant discharge temperature to high pressure compressor 2 to control), by increasing the valve opening of first throttle mechanism 3; Make high pressure compressor 2 export actual refrigerant discharge temperature to reduce, detect the actual temperature of high pressure compressor 2 entrance cold-producing medium simultaneously; Export refrigerant discharge temperature desired value lower than high pressure compressor 2 when high pressure compressor 2 exports actual refrigerant discharge temperature and exceed requirement difference, when the actual temperature of high pressure compressor 2 entrance cold-producing medium and the deviation of high pressure compressor 2 entrance refrigerant temperature desired value are no more than the difference of requirement simultaneously, then abandon alternative plan, reuse third program.

Equally, similar, when using fourth program, namely first throttle mechanism 3 adopts the method changing valve opening, when the refrigerant superheat degree of the Intermediate Heat Exchanger 6 refrigerant side port of export is controlled, detect high pressure compressor 2 simultaneously and export actual refrigerant discharge temperature; Be greater than high pressure compressor 2 export refrigerant discharge temperature desired value when high pressure compressor 2 exports actual refrigerant discharge temperature, and when exceeding requirement difference, then abandon fourth program, (that is: first throttle mechanism 3 adopts the method changing valve opening to use alternative plan, export refrigerant discharge temperature to high pressure compressor 2 to control), by increasing the valve opening of first throttle mechanism 3; Make high pressure compressor 2 export actual refrigerant discharge temperature to reduce, detect the actual degree of superheat of cold-producing medium of the Intermediate Heat Exchanger 6 refrigerant side port of export simultaneously; Export refrigerant discharge temperature desired value lower than high pressure compressor 2 when high pressure compressor 2 exports actual refrigerant discharge temperature and exceed requirement difference, when the deviation of the actual degree of superheat of cold-producing medium of the Intermediate Heat Exchanger 6 refrigerant side port of export and the refrigerant superheat degree desired value of the Intermediate Heat Exchanger 6 refrigerant side port of export is no more than the difference of requirement simultaneously, then abandon alternative plan, reuse fourth program.

In the course of work, high pressure compressor 2 adopts the method changing operating frequency, controls the intermediate pressure of high pressure compressor 2 entrance.Concrete control method is as follows: during work, the intermediate pressure value of the high pressure compressor 2 entrance reality that intermediate pressure sensor 12 detects, be fed to controller 20, in controller 20, compare with intermediate pressure desired value, when the intermediate pressure value of reality is greater than intermediate pressure desired value and exceedes requirement difference, then improve the operating frequency of high pressure compressor 2; When the intermediate pressure value of reality is less than intermediate pressure desired value and exceedes requirement difference, then reduce the operating frequency of high pressure compressor 2; When the intermediate pressure value of reality and the deviate of intermediate pressure desired value are in the scope required, then the operating frequency maintaining high pressure compressor 2 is constant.The intermediate pressure value of above-mentioned reality and the deviate of intermediate pressure desired value are all set in controller 20 in advance.

During work, intermediate pressure desired value depends on the Intermediate Heat Exchanger 6 cooling medium inlet temperature that cooling medium inlet temperature sensor 13 detects; In the scheme shown in the present embodiment Fig. 1, due to cooling medium employing is outdoor air, the inlet air temp of what during work, cooling medium inlet temperature sensor 13 detected is Intermediate Heat Exchanger 6, therefore intermediate pressure desired value depends on the inlet air temp of Intermediate Heat Exchanger 6.

During work, the defining method of intermediate pressure desired value is as follows: the cold-producing medium saturation temperature corresponding to intermediate pressure desired value is set equal to the Intermediate Heat Exchanger 6 cooling medium inlet temperature that cooling medium inlet temperature sensor 13 detects and deducts a heat transfer temperature difference expected; Scheme shown in the present embodiment Fig. 1, that is: the cold-producing medium saturation temperature corresponding to intermediate pressure desired value be set equal to cooling medium inlet temperature sensor 13 detect obtain Intermediate Heat Exchanger 6 inlet air temp deduct one expect heat transfer temperature difference.

The heat transfer temperature difference expected can be set as that a fixed value pre-enters in controller 20; Also can be set as changing value, in advance by the excursion input control device 20 of this changing value, during work, according to the change of other operational factor, in the excursion of changing value, be calculated the heat transfer temperature difference of expectation by controller 20.

No matter the heat transfer temperature difference expected is set as fixed value, be still set as changing value; The cooling medium that its numerical value all adopts with Intermediate Heat Exchanger 6 is closely related.When cooling medium is water, the heat transfer temperature difference A of the expectation of recommendation is: 8 DEG C≤A < 0; When cooling medium is air, the heat transfer temperature difference A of the expectation of recommendation is: 15 DEG C≤A < 0.

During work, utilize said method can obtain cold-producing medium saturation temperature corresponding to intermediate pressure desired value, controller 20 recycles this cold-producing medium saturation temperature by pressure-enthalpy diagram, or the hot Calculation of Physical Properties formula of cold-producing medium determines this intermediate pressure desired value corresponding to cold-producing medium saturation temperature.

But it must be noted that: for pure cold-producing medium, at two-phase section, because refrigerant liquid saturation temperature equals refrigerant gas saturation temperature, therefore, can according to said method, utilize this cold-producing medium saturation temperature by pressure-enthalpy diagram, or the hot Calculation of Physical Properties formula of cold-producing medium uniquely determine this intermediate pressure desired value corresponding to cold-producing medium saturation temperature.But for there is the mix refrigerant of temperature glide at two-phase section, because refrigerant liquid saturation temperature is not equal to refrigerant gas saturation temperature, therefore, according to said method, utilize this cold-producing medium saturation temperature by pressure-enthalpy diagram, or during cold-producing medium hot Calculation of Physical Properties formula determination intermediate pressure desired value, have following two schemes.

Scheme one: the Intermediate Heat Exchanger 6 cooling medium inlet temperature utilizing cooling medium inlet temperature sensor 13 to detect, and the heat transfer temperature difference expected, after calculating the cold-producing medium saturation temperature corresponding to intermediate pressure desired value by above-mentioned method, think that this cold-producing medium saturation temperature is refrigerant gas saturation temperature, then controller 20 recycles this refrigerant gas saturation temperature by pressure-enthalpy diagram, or the hot Calculation of Physical Properties formula of cold-producing medium determines the refrigerant saturation pressure corresponding to it, setting this refrigerant saturation pressure is intermediate pressure desired value.

Scheme two: the Intermediate Heat Exchanger 6 cooling medium inlet temperature utilizing cooling medium inlet temperature sensor 13 to detect, and the heat transfer temperature difference expected, after calculating the cold-producing medium saturation temperature corresponding to intermediate pressure desired value by above-mentioned method, think that this cold-producing medium saturation temperature is refrigerant liquid saturation temperature, then controller 20 recycles this refrigerant liquid saturation temperature by pressure-enthalpy diagram, or the hot Calculation of Physical Properties formula of cold-producing medium determines the refrigerant saturation pressure corresponding to it, setting this refrigerant saturation pressure is intermediate pressure desired value.

In the course of work, cooling medium consumption adjusting device 15 adopts the method changed by the cooling medium consumption of Intermediate Heat Exchanger 6, controls the heat medium outlet temperature of heating-medium heat exchanger 7.

In the scheme shown in the present embodiment Fig. 1, because heating-medium heat exchanger 7 is for the production of domestic hot-water, what the cooling medium of Intermediate Heat Exchanger 6 adopted is air, therefore during work, cooling medium consumption adjusting device 15 adopts the method changed by Intermediate Heat Exchanger 6 air mass flow, controls domestic hot-water's outlet temperature of heating-medium heat exchanger 7.

Concrete control method is as follows: during work, the domestic hot-water that heat medium outlet temperature sensor 14 detects actual outlet water temperature, be fed to controller 20, in controller 20, export water temperature desired value with the domestic hot-water preset to compare, when domestic hot-water's actual outlet water temperature be greater than domestic hot-water export water temperature desired value and exceed requirement difference time, then cooling medium consumption adjusting device 15 action, is reduced by the air mass flow of Intermediate Heat Exchanger 6; When domestic hot-water's actual outlet water temperature be less than domestic hot-water export water temperature desired value and exceed requirement difference time, then cooling medium consumption adjusting device 15 action, increases the air mass flow by Intermediate Heat Exchanger 6; When the deviate that domestic hot-water's actual outlet water temperature and domestic hot-water export water temperature desired value is in the scope required, then cooling medium consumption adjusting device 15 is failure to actuate, and remains constant by the air mass flow of Intermediate Heat Exchanger 6.Above-mentioned domestic hot-water exports the deviate that water temperature desired value, domestic hot-water actual outlet water temperature and domestic hot-water export water temperature desired value and is set in advance in controller 20; Export water temperature desired value for domestic hot-water, it also manually can be inputted by the touch screen of controller 20 or hand push button.

Due in the scheme shown in the present embodiment Fig. 1, the frequency conversion fan that cooling medium consumption adjusting device 15 adopts, therefore in the course of work, when needing the air mass flow being reduced by Intermediate Heat Exchanger 6, cooling medium consumption adjusting device 15 adopts the operating frequency reducing frequency conversion fan to realize; When needing to increase the air mass flow by Intermediate Heat Exchanger 6, cooling medium consumption adjusting device 15 adopts the operating frequency improving frequency conversion fan to realize.

Embodiment 2

The present embodiment is the further improvement to scheme control method shown in embodiment 1 Fig. 1, and according to embodiment 1, in the course of the work, high pressure compressor 2 adopts the method changing operating frequency, controls the intermediate pressure of high pressure compressor 2 entrance; Cooling medium consumption adjusting device 15 adopts the method changed by the cooling medium consumption of Intermediate Heat Exchanger 6, controls the heat medium outlet temperature of heating-medium heat exchanger 7.The defect that said method exists is: in the course of work, when high pressure compressor 2 is in maximum operating frequency, will lose the control to high pressure compressor 2 entrance intermediate pressure.

The control method of the present embodiment to the further improvement of scheme control method shown in embodiment 1 Fig. 1 is:

1) in the course of work, at high pressure compressor 2, cooling medium consumption adjusting device 15 adopts the control method described in embodiment 1, respectively to the intermediate pressure of high pressure compressor 2 entrance, when the heat medium outlet temperature of heating-medium heat exchanger 7 carries out controlling, even if when high pressure compressor 2 works under maximum operating frequency, but the intermediate pressure value of reality is still greater than intermediate pressure desired value, and when exceeding requirement difference, cooling medium consumption adjusting device 15 is then used to adopt the method changed by the cooling medium consumption of Intermediate Heat Exchanger 6, the intermediate pressure of high pressure compressor 2 entrance is controlled, simultaneously, heat medium outlet temperature sensor 14 is utilized to continue to detect the actual outlet temperature of heating agent of heating-medium heat exchanger 7 (in scheme shown in Fig. 1, namely the actual outlet temperature of heating agent of heating-medium heat exchanger 7 is domestic hot-water's actual outlet water temperature),

2) the actual outlet temperature of heating agent of the heating-medium heat exchanger 7 detected at heat medium outlet temperature sensor 14 is higher than heat medium outlet temperature desired value and before exceeding requirement difference, high pressure compressor 2 works under remaining on maximum operating frequency always;

3) the actual outlet temperature of heating agent of the heating-medium heat exchanger 7 but when heat medium outlet temperature sensor 14 detected is higher than heat medium outlet temperature desired value, and after exceeding requirement difference, then high pressure compressor 2 adopts the method changing operating frequency, to the heat medium outlet temperature of heating-medium heat exchanger 7 (in scheme shown in Fig. 1, heat medium outlet temperature and the domestic hot-water of heating-medium heat exchanger 7 export water temperature) control, until the actual operating frequency of high pressure compressor 2 is lower than the maximum operating frequency of high pressure compressor 2, and its deviate be greater than high pressure compressor 2 expect operating frequency deviate after, then high pressure compressor 2, cooling medium consumption adjusting device 15 is recovered to adopt the control method described in embodiment 1, that is: high pressure compressor 2 adopts the method changing operating frequency, the intermediate pressure of high pressure compressor 2 entrance is controlled, cooling medium consumption adjusting device 15 adopts the method changed by the cooling medium consumption of Intermediate Heat Exchanger 6, controls the heat medium outlet temperature of heating-medium heat exchanger 7.

In the improvement project of the above-mentioned control method of the present embodiment, during work, the operating frequency deviate that high pressure compressor 2 is expected pre-enters in controller 20.Cooling medium consumption adjusting device 15 adopts the method changed by the cooling medium consumption of Intermediate Heat Exchanger 6, and the concrete control method controlled the intermediate pressure of high pressure compressor 2 entrance is as follows:

During work, the intermediate pressure value of the high pressure compressor 2 entrance reality that intermediate pressure sensor 12 detects, be fed to controller 20, in controller 20, compare with intermediate pressure desired value, when the intermediate pressure value of reality is greater than intermediate pressure desired value and exceedes requirement difference, then cooling medium consumption adjusting device 15 action, is reduced by the cooling medium consumption of Intermediate Heat Exchanger 6; When the intermediate pressure value of reality is less than intermediate pressure desired value and exceedes requirement difference, then cooling medium consumption adjusting device 15 action, increases the cooling medium consumption by Intermediate Heat Exchanger 6; When the intermediate pressure value of reality and the deviate of intermediate pressure desired value are in the scope required, then cooling medium consumption adjusting device 15 is failure to actuate, and remains constant by the cooling medium consumption of Intermediate Heat Exchanger 6.

Due in the scheme shown in Fig. 1, cooling medium is air, what cooling medium consumption adjusting device 15 adopted is frequency conversion fan, therefore in the course of work, when needing cooling medium consumption (i.e. the air mass flow) being reduced by Intermediate Heat Exchanger 6, cooling medium consumption adjusting device 15 adopts the operating frequency reducing frequency conversion fan to realize; When needing to increase cooling medium consumption (i.e. the air mass flow) by Intermediate Heat Exchanger 6, cooling medium consumption adjusting device 15 adopts the operating frequency improving frequency conversion fan to realize.

In the improvement project of the above-mentioned control method of the present embodiment, when high pressure compressor 2 adopts the method changing operating frequency, when controlling the heat medium outlet temperature (i.e. domestic hot-water's outlet temperature) of heating-medium heat exchanger 7, concrete control method is as follows:

During work, the domestic hot-water that heat medium outlet temperature sensor 14 detects actual outlet water temperature, be fed to controller 20, in controller 20, export water temperature desired value with the domestic hot-water preset to compare, when domestic hot-water's actual outlet water temperature be greater than domestic hot-water export water temperature desired value and exceed requirement difference time, then reduce the operating frequency of high pressure compressor 2; When domestic hot-water's actual outlet water temperature be less than domestic hot-water export water temperature desired value and exceed requirement difference time, then increase the operating frequency of high pressure compressor 2; When the deviate that domestic hot-water's actual outlet water temperature and domestic hot-water export water temperature desired value is in the scope required, then the operating frequency of maintenance high pressure compressor 2 is constant.

Embodiment 3

As shown in Figure 2, the difference of operation of air conditioning systems shown in it and embodiment 1 Fig. 1 is: in the operation of air conditioning systems shown in the present embodiment Fig. 2, and the cooling medium that Intermediate Heat Exchanger 6 adopts is cooling water, so Intermediate Heat Exchanger 6 is a cold-producing medium--water-to-water heat exchangers; Cooling medium inlet temperature sensor 13 is arranged at the arrival end of Intermediate Heat Exchanger 6 cooling water, for detecting cooling water inlet temperature; Cooling medium consumption adjusting device 15 is cooling water pumps, and is variable frequency pump, by changing the method for cooling water pump operating frequency, regulates cooling medium (i.e. cooling water) flow by Intermediate Heat Exchanger 6.

In the course of work, scheme shown in the present embodiment Fig. 2 also can adopt the embodiment of the present invention 1 for the control method described in scheme shown in Fig. 1.

When the cooling medium consumption adjusting device 15 (i.e. cooling water pump) of scheme shown in the present embodiment Fig. 2 adopts the method changed by cooling medium (i.e. cooling water) flow of Intermediate Heat Exchanger 6, when controlling the heat medium outlet temperature (i.e. domestic hot-water's outlet temperature) of heating-medium heat exchanger 7, concrete control method is as follows:

During work, the domestic hot-water that heat medium outlet temperature sensor 14 detects actual outlet water temperature, be fed to controller 20, in controller 20, export water temperature desired value with the domestic hot-water preset to compare, when domestic hot-water's actual outlet water temperature be greater than domestic hot-water export water temperature desired value and exceed requirement difference time, then reduce the operating frequency of cooling medium consumption adjusting device 15 (i.e. cooling water pump), be reduced by cooling medium (i.e. cooling water) flow of Intermediate Heat Exchanger 6; When domestic hot-water's actual outlet water temperature be less than domestic hot-water export water temperature desired value and exceed requirement difference time, then improve the operating frequency of cooling medium consumption adjusting device 15 (i.e. cooling water pump), increase cooling medium (i.e. cooling water) flow by Intermediate Heat Exchanger 6; When the deviate that domestic hot-water's actual outlet water temperature and domestic hot-water export water temperature desired value is in the scope required, then the operating frequency of cooling medium consumption adjusting device 15 (i.e. cooling water pump) is constant, remains constant by cooling medium (i.e. cooling water) flow of Intermediate Heat Exchanger 6.

In the course of work, the further improvement project that the embodiment of the present invention 2 is done for control method described in embodiment 1 is also applicable to scheme shown in the present embodiment Fig. 2.

When the cooling medium consumption adjusting device 15 (i.e. cooling water pump) of scheme shown in the present embodiment Fig. 2 adopts the method changed by cooling medium (i.e. cooling water) flow of Intermediate Heat Exchanger 6, when controlling the intermediate pressure of high pressure compressor 2 entrance, concrete control method is as follows:

During work, the intermediate pressure value of the high pressure compressor 2 entrance reality that intermediate pressure sensor 12 detects, be fed to controller 20, in controller 20, compare with intermediate pressure desired value, when the intermediate pressure value of reality is greater than intermediate pressure desired value and exceedes requirement difference, then reduce the operating frequency of cooling medium consumption adjusting device 15 (i.e. cooling water pump), be reduced by cooling medium (i.e. cooling water) flow of Intermediate Heat Exchanger 6; When the intermediate pressure value of reality is less than intermediate pressure desired value and exceedes requirement difference, then improve the operating frequency of cooling medium consumption adjusting device 15 (i.e. cooling water pump), increase cooling medium (i.e. cooling water) flow by Intermediate Heat Exchanger 6; When the intermediate pressure value of reality and the deviate of intermediate pressure desired value are in the scope required, then the operating frequency of cooling medium consumption adjusting device 15 (i.e. cooling water pump) is constant, remains constant by cooling medium (i.e. cooling water) flow of Intermediate Heat Exchanger 6.

In the scheme shown in the present embodiment Fig. 2, due to cooling medium employing is cooling water, the cooling water inlet temperature of what during work, cooling medium inlet temperature sensor 13 detected is Intermediate Heat Exchanger 6, therefore in the scheme shown in the present embodiment Fig. 2, intermediate pressure desired value depends on the cooling water inlet temperature of Intermediate Heat Exchanger 6.

Embodiment 4

As shown in Figure 3, the difference of operation of air conditioning systems shown in it and the embodiment of the present invention 3 Fig. 2 is: in the operation of air conditioning systems shown in the present embodiment Fig. 3, cooling medium consumption adjusting device 15 is two-way electric control valves, during work, by changing the method for the valve opening of two-way electric control valve, cooling medium (i.e. cooling water) flow by Intermediate Heat Exchanger 6 is regulated.

In the course of work, scheme shown in the present embodiment Fig. 3 also can adopt the embodiment of the present invention 1 for the control method described in scheme shown in Fig. 1.

When the cooling medium consumption adjusting device 15 (i.e. two-way electric control valve) of scheme shown in the present embodiment Fig. 3 adopts the method changed by cooling medium (i.e. cooling water) flow of Intermediate Heat Exchanger 6, when controlling the heat medium outlet temperature (i.e. domestic hot-water's outlet temperature) of heating-medium heat exchanger 7, concrete control method is as follows:

During work, the domestic hot-water that heat medium outlet temperature sensor 14 detects actual outlet water temperature, be fed to controller 20, in controller 20, export water temperature desired value with the domestic hot-water preset to compare, when domestic hot-water's actual outlet water temperature be greater than domestic hot-water export water temperature desired value and exceed requirement difference time, then reduce the valve opening of cooling medium consumption adjusting device 15 (i.e. two-way electric control valve), be decreased through cooling medium (i.e. cooling water) flow of Intermediate Heat Exchanger 6; When domestic hot-water's actual outlet water temperature be less than domestic hot-water export water temperature desired value and exceed requirement difference time, then increase the valve opening of cooling medium consumption adjusting device 15 (i.e. two-way electric control valve), increase cooling medium (i.e. cooling water) flow by Intermediate Heat Exchanger 6; When the deviate that domestic hot-water's actual outlet water temperature and domestic hot-water export water temperature desired value is in the scope required, then the valve opening of cooling medium consumption adjusting device 15 (i.e. two-way electric control valve) is constant, remains constant by cooling medium (i.e. cooling water) flow of Intermediate Heat Exchanger 6.

In the course of work, the improvement project that the embodiment of the present invention 2 is done for control method described in embodiment 1 is also applicable to scheme shown in the present embodiment Fig. 3.

When the cooling medium consumption adjusting device 15 (i.e. two-way electric control valve) of scheme shown in the present embodiment Fig. 3 adopts the method changed by cooling medium (i.e. cooling water) flow of Intermediate Heat Exchanger 6, when controlling the intermediate pressure of high pressure compressor 2 entrance, concrete control method is as follows:

During work, the intermediate pressure value of the high pressure compressor 2 entrance reality that intermediate pressure sensor 12 detects, be fed to controller 20, in controller 20, compare with intermediate pressure desired value, when the intermediate pressure value of reality is greater than intermediate pressure desired value and exceedes requirement difference, then reduce the valve opening of cooling medium consumption adjusting device 15 (i.e. two-way electric control valve), be reduced by cooling medium (i.e. cooling water) flow of Intermediate Heat Exchanger 6; When the intermediate pressure value of reality is less than intermediate pressure desired value and exceedes requirement difference, then increase the valve opening of cooling medium consumption adjusting device 15 (i.e. two-way electric control valve), improve cooling medium (i.e. cooling water) flow by Intermediate Heat Exchanger 6; When the intermediate pressure value of reality and the deviate of intermediate pressure desired value are in the scope required, then the valve opening of cooling medium consumption adjusting device 15 (i.e. two-way electric control valve) is constant, remains constant by cooling medium (i.e. cooling water) flow of Intermediate Heat Exchanger 6.

In the scheme shown in the present embodiment Fig. 3, due to cooling medium employing is cooling water, the cooling water inlet temperature of what during work, cooling medium inlet temperature sensor 13 detected is Intermediate Heat Exchanger 6, therefore in the scheme shown in the present embodiment Fig. 3, intermediate pressure desired value is the cooling water inlet temperature depending on Intermediate Heat Exchanger 6.

Embodiment 5

As shown in Figure 4, the difference of operation of air conditioning systems shown in it and the embodiment of the present invention 1 Fig. 1 is: in the operation of air conditioning systems shown in the present embodiment Fig. 4, add a liquid reservoir 30, under regulating different operating condition, the refrigerant circulation flow of operation of air conditioning systems.

Liquid reservoir 30 connected mode is in systems in which: liquid reservoir 30 entrance is connected with the heating-medium heat exchanger 7 refrigerant side port of export; Liquid reservoir 30 low tension outlet is connected with second throttle body 4 arrival end; First throttle mechanism 3 port of export is connected with Intermediate Heat Exchanger 6 refrigerant side arrival end, first throttle mechanism 3 arrival end with extrude mouth, the pipeline between liquid reservoir 30 entrance and the heating-medium heat exchanger 7 refrigerant side port of export or the pipeline three between liquid reservoir 30 low tension outlet and second throttle body 4 arrival end in liquid reservoir 30 among any place be connected.

Above-mentioned liquid reservoir 30 connected mode in systems in which of the present embodiment is applicable to all described scheme of all embodiments of the present invention.

In the scheme of the above-mentioned all embodiments of the present invention, in described low pressure compressor 1, high pressure compressor 2 any one or all, can adopt in following compressor any one: screw compressor, helical-lobe compressor, rolling rotor compressor, sliding-vane compressor, rotary blade type compressor, centrifugal compressor, digital scroll compressor; In low pressure compressor 1, high pressure compressor 2 any one or all, also can be variable conpacitance compressor (such as: frequency-changeable compressor), or constant speed compressor.

In the scheme of above-mentioned all embodiments, heating-medium heat exchanger 7 as cold-producing medium-water-to-water heat exchanger, usually adopt in plate type heat exchanger, volumetric heat exchanger, shell and tube exchanger or double pipe heat exchanger any one.

In the scheme of above-mentioned all embodiments, Intermediate Heat Exchanger 6 is except can being refrigerant-air heat exchanger, also can be cold-producing medium-soil heat exchanger, cold-producing medium-water-to-water heat exchanger, also can be evaporating heat exchanger, in addition, also can be the heat exchanger of other kind; During as cold-producing medium-water-to-water heat exchanger, Intermediate Heat Exchanger 6 usually adopt in plate type heat exchanger, volumetric heat exchanger, shell and tube exchanger or double pipe heat exchanger any one.

In the scheme of above-mentioned all embodiments, when refrigerant heat exchanger 5 is as cold-producing medium-water-to-water heat exchanger, usually adopt any one in volumetric heat exchanger, plate type heat exchanger, shell and tube exchanger or double pipe heat exchanger, or the heat exchanger of other kind as required.

When Intermediate Heat Exchanger 6 is as refrigerant-air heat exchanger, usually adopt finned heat exchanger, the fin of described finned heat exchanger is generally aluminum or aluminum alloy material, and the occasion special at some also uses copper material.The shape of fin usually adopt in plate, ripple type or slitted fin type any one.

Claims

1. an operation of air conditioning systems, comprises low pressure compressor (1), high pressure compressor (2), first throttle mechanism (3), second throttle body (4), refrigerant heat exchanger (5), Intermediate Heat Exchanger (6) and heating-medium heat exchanger (7);

2. a control method for operation of air conditioning systems, described operation of air conditioning systems comprises low pressure compressor (1), high pressure compressor (2), first throttle mechanism (3), second throttle body (4), refrigerant heat exchanger (5), Intermediate Heat Exchanger (6), heating-medium heat exchanger (7), intermediate pressure sensor (12), cooling medium inlet temperature sensor (13), heat medium outlet temperature sensor (14) and cooling medium consumption adjusting device (15);

3. operation of air conditioning systems control method according to claim 2, it is characterized in that described cooling medium consumption adjusting device (15) flows through the method for the cooling medium consumption of Intermediate Heat Exchanger (6) by change, the heat medium outlet temperature of described heating-medium heat exchanger (7) is controlled as desired value.

4. a control method for operation of air conditioning systems, described operation of air conditioning systems comprises low pressure compressor (1), high pressure compressor (2), first throttle mechanism (3), second throttle body (4), refrigerant heat exchanger (5), Intermediate Heat Exchanger (6), heating-medium heat exchanger (7), intermediate pressure sensor (12), cooling medium inlet temperature sensor (13), heat medium outlet temperature sensor (14) and cooling medium consumption adjusting device (15);

5. operation of air conditioning systems control method according to claim 4, it is characterized in that described high pressure compressor (2) is frequency-changeable compressor, in the course of work, controlling intermediate pressure by the method changing high pressure compressor (2) operating frequency is desired value.

6. the operation of air conditioning systems control method according to claim 2 or 5, is characterized in that described intermediate pressure desired value depends on the cooling medium inlet temperature that described cooling medium inlet temperature sensor (13) is detected.

7. operation of air conditioning systems control method according to claim 6, the cold-producing medium saturation temperature that it is characterized in that corresponding to described intermediate pressure desired value is set equal to the cooling medium inlet temperature that described cooling medium inlet temperature sensor (13) detects and deducts a heat transfer temperature difference expected.

8. the operation of air conditioning systems control method according to claim arbitrary in claim 2 to 5, it is characterized in that a high pressure compressor (2) refrigerant inlet temperature sensor (11) is arranged on described high pressure compressor (2) arrival end pipeline, for detecting the actual refrigerant temperature of described high pressure compressor (2) arrival end; Described high pressure compressor (2) entrance refrigerant superheat degree, by regulating the method for its valve opening, controls as desired value by described first throttle mechanism (3).

9. the operation of air conditioning systems control method according to claim arbitrary in claim 2 to 5, it is characterized in that a high pressure compressor (2) refrigerant inlet temperature sensor (11) is arranged on described high pressure compressor (2) arrival end pipeline, for detecting the actual refrigerant temperature of described high pressure compressor (2) arrival end; Described high pressure compressor (2) entrance coolant temperature control, by regulating the method for its valve opening, is desired value by described first throttle mechanism (3).

10. the operation of air conditioning systems control method according to claim arbitrary in claim 2 to 5, it is characterized in that described high pressure compressor (2) port of export pipeline is provided with a refrigerant discharge temperature sensor, for detecting the actual refrigerant discharge temperature of high pressure compressor (2) outlet; Described first throttle mechanism (3), by regulating the method for its valve opening, controls described high pressure compressor (2) outlet refrigerant discharge temperature.

11. operation of air conditioning systems control methods according to claim arbitrary in claim 2 to 5, it is characterized in that described first throttle mechanism (3) is by regulating the method for its valve opening, controls the refrigerant superheat degree of described Intermediate Heat Exchanger (6) the refrigerant side port of export.