WO2015042970A1

WO2015042970A1 - Cooling system and heating system

Info

Publication number: WO2015042970A1
Application number: PCT/CN2013/084749
Authority: WO
Inventors: 高斌; 向卫民; 喻继江; 郭宏; 杨泾涛; 张�诚
Original assignee: 广东美芝制冷设备有限公司
Priority date: 2013-09-30
Filing date: 2013-09-30
Publication date: 2015-04-02
Also published as: AU2013383644B2; AU2013383644A1; EP2977691A4; EP2977691A1; AU2013383644A8; EP2977691B1

Abstract

Disclosed are a cooling system (100) and a heating system (200). The cooling system (100) comprises: a low-backpressure rotary compressor (1), a four-way valve (2), an outdoor heat exchanger (3), an indoor heat exchanger (4), a throttle element (4) and a control valve assembly (6), wherein a housing of the low-backpressure rotary compressor (1) is provided with an upper air suction pipe (S1), a middle air suction pipe (S2) and an air discharge pipe (D). The control valve assembly (6) is connected to an air suction valve port (21), the upper air suction pipe (S1) and the middle air suction pipe (S2), respectively via a first pipeline (G), a second pipeline (F) and a third pipeline (E). When the cooling system is in a cooling mode, the control valve assembly (6) controls the suctioned air flow of the third pipeline (E) to be greater than that of the second pipeline (F), and when the cooling system is in a heating mode, the control valve assembly (6) controls the suctioned air flow of the second pipeline (F) to be greater than that of the third pipeline (E).

Description

Refrigeration system and heating system

Technical field

The invention relates to the field of household appliances, and in particular to a refrigeration system and a heating system. Background technique

The motor of the existing low back pressure rotary compressor is arranged in the casing. During the operation of the compressor, the motor generates heat due to loss, and the inside of the casing is a low temperature and low pressure environment communicating with the suction pipe, resulting in inhalation. The low-temperature and low-pressure gas exchanges heat with the motor, which can cool the motor on the one hand, ensure the reliability of the motor, and heat the inhaled gas on the other hand, thus affecting the performance of the refrigeration cycle.

For a refrigeration system equipped with a low back pressure rotary compressor, the refrigeration performance in the refrigeration cycle is fundamentally affected by the heating of the suction and the heating performance is affected by the heating of the suction, so it should be operated according to the refrigeration unit. The characteristics of the cooling mode or the heating mode are designed in a targeted manner to achieve the dual purpose of improving the performance of the refrigeration system and meeting the cooling requirements of the motor. Summary of the invention

The present invention aims to solve at least one of the technical problems existing in the prior art.

Accordingly, it is an object of the present invention to provide a refrigeration system that achieves the dual purpose of optimizing the performance of the refrigeration system and meeting the cooling needs of the motor.

Another object of the present invention is to provide a heating system capable of ensuring the reliability of the motor to the utmost extent.

A refrigeration system according to an embodiment of the first aspect of the present invention, comprising: a low back pressure rotary compressor, the low back pressure rotary compressor including a housing and a motor, a compression mechanism disposed in the housing, An upper suction pipe is disposed on an upper portion of the casing, an intermediate suction pipe is disposed in a middle portion of the casing, and an exhaust pipe is further disposed on the casing; a four-way valve, the four-way valve has an exhaust valve port , an intake valve port, an outdoor heat exchanger valve port and an indoor heat exchanger valve port, the exhaust valve port is connected to the exhaust pipe; an outdoor heat exchanger, one end of the outdoor heat exchanger and the The outdoor heat exchanger valve port is connected; the indoor heat exchanger, one end of the indoor heat exchanger is connected to the indoor heat exchanger valve port, and the other end of the indoor heat exchanger is opposite to the outdoor heat exchanger a throttle element, the throttle element is connected in series between the outdoor heat exchanger and the indoor heat exchanger; a control valve assembly, the control valve assembly and the suction valve port, the upper The suction pipe and the intermediate suction pipe are connected by the first pipe, the second pipe and the third pipe, respectively. Said control valve assembly when the refrigeration system in a cooling mode, controls said third conduit is greater than the intake air flow rate of the intake air flow rate of the second conduit, said control The valve assembly controls an intake flow rate of the second conduit to be greater than an intake flow rate of the third conduit when the refrigeration system is in a heating mode.

According to the refrigeration system of the embodiment of the present invention, when the refrigeration system is in the cooling mode, the intake flow rate of the third pipe is controlled to be larger than the intake flow rate of the second pipe, and the control valve assembly is controlled when the refrigeration system is in the heating mode. The suction flow rate of the second pipe is larger than the suction flow rate of the third pipe, so that when the refrigeration system is in the cooling mode, the inhaled gas is mainly sucked through the intermediate suction pipe, and does not need to pass through the motor, thereby reducing the heating of the suction gas by the motor. Degree, which reduces the performance deterioration caused by heating. At the same time, a small amount of gas is allowed to be sucked from the upper suction pipe, and the motor is cooled by the motor to ensure the reliability of the motor, and when the refrigeration system is in the heating mode, the air is sucked. The gas is mainly sucked through the upper suction pipe, and the motor is cooled by the motor to ensure the reliability of the motor to the utmost extent.

In addition, the refrigeration system according to the invention also has the following additional technical features:

Specifically, in the cooling mode, a ratio of an intake flow rate of the third conduit to an intake flow rate of the first conduit is greater than or equal to 0.6.

Further, in the cooling mode, the inspiratory flow rate in the third conduit is equal to the inspiratory flow rate in the first conduit.

Specifically, in the heating mode, a ratio of an intake flow rate of the second conduit to an intake flow rate of the first conduit is greater than or equal to 0.6.

Further, in the heating mode, the inspiratory flow rate of the second conduit is equal to the inspiratory flow rate of the first conduit.

Specifically, the control valve assembly includes first and second control valves disposed on the second conduit and the third conduit, respectively.

In some examples of the invention, the control valve assembly is coupled to the four-way valve to determine that the refrigeration system is in a cooling mode or a heating mode based on a refrigerant flow direction of the four-way valve.

In a specific embodiment of the present invention, the heating capacity or energy efficiency of the refrigerant in the low back pressure rotary compressor increases with the degree of superheat when the evaporation temperature, the condensation temperature, and the subcooling condition are constant. High and rising.

A refrigeration system according to an embodiment of the second aspect of the present invention, comprising: a low back pressure rotary compressor, the low back pressure rotary compressor including a housing and a motor, a compression mechanism disposed in the housing, An upper suction pipe is disposed on an upper portion of the casing, an intermediate suction pipe is disposed in a middle portion of the casing, and an exhaust pipe is further disposed on the casing; an outdoor heat exchanger, one end of the outdoor heat exchanger The exhaust pipe is connected; the indoor heat exchanger, one end of the indoor heat exchanger is connected to the other end of the outdoor heat exchanger; a throttling element, the throttling element is connected in series to the outdoor heat exchanger and Between the indoor heat exchangers; a control valve assembly, the control valve assembly and the other end of the indoor heat exchanger, the upper suction pipe and the intermediate suction pipe pass through the first pipe a second conduit connected to the third conduit, the control valve assembly controlling the third The suction flow rate of the pipe is greater than the suction flow rate of the second pipe.

According to the refrigeration system of the embodiment of the present invention, the control valve assembly controls the suction flow rate of the third pipe to be larger than the suction flow rate of the second pipe, and the inhaled gas is mainly sucked through the intermediate suction pipe, and does not need to pass through the motor, thereby reducing the motor pair. The degree of heating of the inhaled gas reduces the deterioration of performance due to heating. At the same time, a small amount of gas is allowed to be sucked from the upper suction pipe, and the motor is cooled by the motor to ensure the reliability of the motor, and the suction belt is prevented to the maximum extent. The problem of degraded performance is to improve the performance of the compressor and system.

Specifically, the ratio of the inspiratory flow rate of the third conduit to the inspiratory flow rate of the first conduit is greater than or equal to 0.6. Further, the inspiratory flow rate of the third conduit is equal to the inspiratory flow rate of the first conduit.

Specifically, the refrigerant is one of R290, R134a, and R410A.

Optionally, the control valve assembly is a three-way valve.

A heating system according to an embodiment of the third aspect of the present invention, comprising: a low back pressure rotary compressor, the low back pressure rotary compressor including a housing and a motor and a compression mechanism disposed in the housing An upper suction pipe is disposed on an upper portion of the casing, an intermediate suction pipe is disposed in a middle portion of the casing, and an exhaust pipe is further disposed on the casing; an indoor heat exchanger, one end of the indoor heat exchanger Connected to the exhaust pipe; an outdoor heat exchanger, one end of the outdoor heat exchanger is connected to the other end of the indoor heat exchanger; a throttling element, the throttling element is connected in series to the indoor changer And the outdoor heat exchanger; a control valve assembly, the control valve assembly and the outdoor heat exchanger, the upper suction pipe and the intermediate suction pipe are respectively connected through the first pipe, the second pipe and the third pipe The control valve assembly controls an intake flow rate of the second conduit to be greater than an intake flow rate of the third conduit.

According to the heating system of the embodiment of the invention, the control valve assembly controls the suction flow rate of the second pipe F to be larger than the suction flow rate of the third pipe E, so that the suction air passes through the motor to cool the motor, thereby maximally ensuring the reliability of the motor. .

In addition, the heating system according to the invention also has the following additional technical features:

Specifically, a ratio of an inspiratory flow rate of the second conduit to an inspiratory flow rate of the first conduit is greater than or equal to 0.8. Further, the inspiratory flow rate of the second conduit is equal to the inspiratory flow rate of the first conduit.

In a specific embodiment of the invention, the refrigerant in the low back pressure rotary compressor is a mixed refrigerant containing R32, and the R32 accounts for 50% by mass or less.

Optionally, the control valve assembly is a three-way valve.

In some embodiments of the invention, the heating system is a heat pump water heater, and the indoor heat exchanger is disposed in a water tank for heating water in the water tank. The additional aspects and advantages of the invention will be set forth in part in the description which follows. DRAWINGS

The above and/or additional aspects and advantages of the present invention will become apparent and readily understood from

Figure 1 is a refrigeration cycle diagram of a refrigerant at different degrees of superheat;

Figure 2 is a graph showing the change trend of the heating capacity of the refrigerant R134a with respect to different superheat degrees;

Figure 3 is a graph showing the change trend of the heating energy efficiency of the refrigerant R134a with respect to different superheat degrees;

Figure 4 is a graph showing the change trend of the heating capacity of the refrigerant R32 with respect to different superheat degrees;

Figure 5 is a graph showing the change trend of the heating energy efficiency of the refrigerant R32 with respect to different superheat degrees;

Fig. 6 is a graph showing the change trend of the heating capacity of the refrigerant R410A containing R32 with respect to different superheat degrees; Fig. 7 is a graph showing the change trend of the heating energy efficiency of the refrigerant R410A containing R32 with respect to different superheat degrees; A schematic view of a low back pressure rotary compressor of an embodiment of the present invention;

Figure 9 is a schematic illustration of a refrigeration system in accordance with one embodiment of the present invention;

Figure 10 is a schematic illustration of a refrigeration system in accordance with still another embodiment of the present invention;

Figure 11 is a schematic illustration of a heating system in accordance with an embodiment of the present invention. Reference mark:

Refrigeration system 100, heating system 200, low back pressure rotary compressor

Upper suction pipe Sl, intermediate suction pipe S2, exhaust pipe D, upper casing 11,

Main housing 12, lower housing 13, four-way valve 2, exhaust valve port 20, suction valve port 21,

Outdoor heat exchanger valve port 22, indoor heat exchanger valve port 23, outdoor heat exchanger 3,

Indoor heat exchanger 5, throttling element 4, control valve assembly 6, first pipe 0,

Second pipe! ^, the third pipe 5, the water tank 9

The embodiments of the present invention are described in detail below, and the examples of the embodiments are illustrated in the drawings, wherein the same or similar reference numerals are used to refer to the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the drawings are intended to be illustrative only and not to limit the invention.

In the description of the present invention, it is to be understood that the terms "center", "upper", "lower", "previous", "after", The orientation or positional relationship of the indications "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. is based on the orientation or positional relationship shown in the drawings. The present invention and the simplification of the description are merely for the purpose of describing the present invention and the simplification of the invention, and the invention is not to be construed as limiting the invention.

It should be noted that the terms "first" and "second" are used for descriptive purposes only, and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defining "first", "second" may explicitly or implicitly include one or more of the features. Further, in the description of the present invention, "multiple" means two or more unless otherwise stated.

First, the relationship between the suction of the low back pressure rotary compressor and the motor cooling required by the motor and the cooling performance of the refrigeration system will be described below with reference to Figs.

Normally, we can judge the trend of refrigerant performance in actual application based on the theoretical thermodynamic cycle calculation of the refrigerant.

For example, in the following reference conditions, when the evaporating temperature, condensing temperature, and subcooling conditions are constant, the degree of superheat is from 5 ° C to 35 ° C. The performance of the refrigeration cycle changes, for example, the calculated superheat is 5 °C, 15. C, 25 V, 35 °C refrigeration cycle performance trends. Assume that 5 °C is the superheat of the return air of the refrigeration system, while 15 °C, 25 °C, and 35 °C respectively indicate that the suction is heated by the motor, causing the suction temperature to rise by 10 °C, 20 °C, 30 °C. . Among them, the refrigeration cycle at 5 °C superheat is used as a reference, which we call the reference cycle.

For the sake of simplicity, the following is still illustrated with the total superheat representing different cycling conditions.

The calculation conditions are as shown in Table 1 below:

Table 1 Reference conditions calculation conditions

In the pressure-焓 diagram of the refrigerant, that is, the lg ph diagram, the compressed vapor refrigeration cycle can be represented as shown in Fig. 1. In Fig. 1, the abscissa is the 焓 value and the ordinate is the pressure value. The cycle at 5 °C superheat indicated in Figure 1 is la-2a-3-4-5-la, and the cycle at 15 °C superheat is lb-2b-3-4-5-lb, 25 °C The cycle at superheat is lc-2c-3-4-5-lc, and the cycle at 35 °C superheat is ld-2d-3-4-5-ld, where points la, lb, lc, The temperature difference between the temperature of the Id point and the point 1 is the degree of superheat.

In Fig. 1, the 焓 value is represented by H, and the 焓 value of each point is represented by a dot code as a subscript, for example, HI represents the 焓 value of point 1, and H2a represents the 焓 value of point 2a. In addition, the cycle quality is represented by K, where K5 represents the superheat of 5 °C. Refrigerant cycle quality, K15 represents the refrigerant cycle quality at 15 °C superheat, and so on.

The following is an example of the comparison of the refrigeration and heating performance of the refrigeration cycle with the superheat of 25 °C and the reference cycle:

At 5 ° C superheat, the performance of the refrigeration cycle is calculated as follows:

Qc = (Hla-H5) * K5

Qh = (H2a-H4) * K5

P= (H2a-Hla) * K5

COPc = Qc/P

COPh = Qh/P

among them:

Qc: Cooling capacity

Qh: Heating capacity

P: compression power

COPc: Cooling Energy Efficiency

COPh: Heating Energy Efficiency

When the suction is heated by the motor, taking the refrigeration cycle with a superheat of 25 °C as an example, the calculation of the refrigeration cycle performance is:

Qc = (Hla-H5) * K25

Qh= (H2c-H4) * K25

P= (H2c-Hlc) * K25

COPc = Qc/P

COPh = Qh/P

First analyze the refrigeration cycle. After the suction is heated by the motor, the specific volume of the gas increases, and the suction volume of the compressor is constant, so that the circulation quality of the refrigerant is reduced, that is, K25 < K5. Since the motor is heated and ineffectively superheated, the enthalpy difference of the cooling system is constant, and is still calculated as (Hla-H5). Therefore, Qc is reduced, that is, the suction is heated, which causes the cooling capacity to decrease. For the compression power, compared to the reference cycle, since (H2c-Hlc) increases and K25 decreases, the P value cannot be determined, making COPc undeterminable. In fact, for most refrigerants, COPc is also on a downward trend.

Therefore, it is necessary to draw in the gas through the intermediate suction pipe S2 to reduce the degree of heating of the suction by the motor. However, since the motor needs to be cooled, it may be necessary to appropriately allow the upper casing suction pipe S1 to suck in the low-temperature gas to cool the motor, especially the gas sucked in the intermediate suction pipe S2 directly communicates with the suction chamber of the compressor without the motor. Contact situation Next.

That is to say, in the cooling condition, although the performance is sacrificed, it is possible to allow the design of the suction chamber of the compressor directly under the condition that the temperature of the motor is too high or the intermediate suction pipe S2 directly communicates with the suction chamber of the compressor. A small amount of the upper casing inhales to cool the motor. However, under cooling conditions, as much refrigerant as possible should be drawn in from the intermediate suction pipe S2 to reduce the degree of heating of the suction to improve the performance of the compressor and refrigeration system.

Second, analyze the heating cycle. After the suction is heated, the circulation quality of the refrigerant is reduced, that is, K25 < K5, and the enthalpy difference (H2c-H4) for calculating the heating capacity Qh is increased (H2c-H2) compared with the reference cycle, g卩(H2c- H4) Increase, therefore, the heating capacity Qh cannot be determined whether it is rising or falling, and needs to be confirmed according to the actual conditions of different refrigerants.

For example, for R134a refrigerant, the heating capacity and heating energy efficiency COPh change trends as shown below

2 and Figure 3, the abscissa is superheat, and the ordinate is the capacity or energy efficiency percentage. It can be seen that for R134a, as the superheat increases, its heating capacity and energy efficiency are improved.

For R32 refrigerant, the heating capacity and heating energy efficiency COPh are shown in Figure 4 and Figure 5, respectively. It can be seen that for R32, with the increase of superheat, its heating capacity And energy efficiency has significantly deteriorated.

In a refrigeration system using a low back pressure rotary compressor, due to the inevitable motor heating inhalation process, a suitable refrigerant should be used to ensure the performance of the system, especially in the heating conditions. When choosing a suitable refrigerant, the low back pressure rotary compressor can be used to improve the heating performance of the system. The refrigerant which does not deteriorate in heating performance after the increase in superheat degree can be selected by the above theoretical calculation method. Such as R134a, R290, R410A, R161, HF0-1234yf, HFO-1234ze and the like.

Therefore, according to the parameters of the refrigeration cycle of different refrigerants in the respective pressure-enthalpy diagrams, the heating capacity and energy efficiency of different superheat degrees are calculated, and the refrigerant is judged as heating condition. Whether it is suitable for the use of a low back pressure rotary compressor, and, in the heating condition, the ratio of the gas sucked from the upper casing suction pipe S1 to adjust the superheat degree, can be optimally installed with a low back pressure rotary type The heating capacity or energy efficiency of the refrigeration system of the compressor.

In addition, considering the sensitivity of the R32 refrigerant to superheat, in a refrigeration system equipped with a low back pressure rotary compressor, the refrigerant selected should not contain too much R32. According to the theoretical calculation results, for example, R410A refrigerant has a ratio of R32 of 50%, and the calculation results are shown in Fig. 6 and Fig. 7. It can be seen that the performance has reached a critical state. Therefore, in a refrigeration system equipped with a low back pressure rotary compressor, if a mixed refrigerant containing R32 is selected, the mass percentage of R32 should be 50% or less.

In the refrigeration system and heating system, we can adjust the suction pipe S1 and the intermediate suction pipe S2 on the compressor. The inspiratory flow distribution is optimized to optimize the heating performance of the refrigeration system and heating system using different types of refrigerant. For example, when the refrigeration system uses a refrigerant having a markedly improved heating performance as the degree of superheat increases, we can increase the intake amount of the upper suction pipe S1 to improve the heating performance, or even completely suck in the upper casing. For the refrigeration system in which the heating performance of the refrigerant used is critical as the degree of superheat increases, we should give priority to the heating capacity based on the actual situation, such as the system design or the different requirements of the heating COP. Adjust the suction ratio of the upper suction pipe S1 to achieve the desired system performance. A refrigeration system 100 provided with a low back pressure rotary compressor 1 according to two embodiments of the present invention will be described in detail below with reference to Figs. 8-10, which utilizes the principles described above to optimize the performance of the refrigeration system 100 and Meet the dual purpose of motor cooling needs.

Example 1

As shown in FIG. 8 and FIG. 9, a refrigeration system 100 according to an embodiment of the present invention includes: a low back pressure rotary compressor 1, a four-way valve 2, an outdoor heat exchanger 3, an indoor heat exchanger 5, and a throttling Element 4 and control valve assembly 6. The refrigeration system 100 has a cooling mode and a heating mode.

The low back pressure rotary compressor 1 includes a housing, a motor and a compression mechanism, and the housing includes an upper housing 11 and a main housing

12 and a lower casing 13, the upper casing 11 is disposed at an upper portion of the main casing 12, and the lower casing 13 is disposed at a lower portion of the main casing 12, and the upper casing 11, the main casing 12, and the lower casing 13 are collectively defined The internal space of the housing, the motor and the compression mechanism are respectively disposed in the internal space of the housing. The upper part of the casing, that is, the upper casing 11, is provided with an upper suction pipe S1, and the middle part of the casing, that is, the main casing 12 is provided with an intermediate suction pipe S2, and the casing is provided with an exhaust pipe D, which is shown in FIG. In the example, the exhaust pipe D is provided at a lower portion of the main casing 12. The high-pressure gas in the low back pressure rotary compressor 1 is discharged from the exhaust pipe D, and the refrigerant that has passed through the refrigeration cycle or the heating cycle is sucked into the internal space of the casing from the upper intake pipe S1 and the intermediate suction pipe S2. Among them, it is to be understood that the specific structure and working principle of the low back pressure rotary compressor 1 are well known to those skilled in the art and will not be described in detail herein.

The four-way valve 2 has an exhaust valve port 20, an intake valve port 21, an outdoor heat exchanger valve port 22, and an indoor heat exchanger valve port 23, and the exhaust valve port 20 is connected to the exhaust pipe D, and the indoor heat exchanger valve The port 23 is connected to one end of the indoor heat exchanger 5, and the outdoor heat exchanger port 22 is connected to one end of the outdoor heat exchanger 3. When the exhaust valve port 20 of the four-way valve 2 is in communication with the outdoor heat exchanger valve port 22, and the intake valve port 21 is in communication with the indoor heat exchanger valve port 23, the refrigeration system 100 is in the cooling mode, when the four-way valve 2 When the exhaust valve port 20 is in communication with the indoor heat exchanger valve port 23 and the intake valve port 21 is in communication with the outdoor heat exchanger valve port 22, the refrigeration system 100 is in the heating mode. Further, an oil separator may be disposed between the exhaust valve port 20 and the exhaust pipe D to perform oil-gas separation of the refrigerant discharged from the exhaust pipe D. Among them, the structure and working principle of the oil separator are well known to those skilled in the art and will not be described in detail herein. The other end of the indoor heat exchanger 5 is connected to the other end of the outdoor heat exchanger 3. The throttle element 4 is connected in series between the outdoor heat exchanger 3 and the indoor heat exchanger 5. Alternatively, the throttle element 4 is a capillary or solenoid valve.

The control valve assembly 6 is connected to the suction valve port 21, the upper suction pipe S1 and the intermediate suction pipe S2 through the first pipe G, the second pipe F and the third pipe E, respectively, that is, the control valve assembly 6 passes the A pipe G is connected to the suction valve port 21, the control valve assembly 6 is connected to the upper suction pipe S1 through the second pipe F, and the control valve assembly 6 is connected to the intermediate suction pipe S2 through the third pipe E, and the control valve assembly 6 has Acquiring the function of the operating mode (cooling mode or heating mode) of the refrigeration system 100, the control valve assembly 6 controls the intake flow of the second conduit F and the third conduit E according to the operating mode of the refrigeration system 100, in some examples of the invention The control valve assembly 6 includes a first control valve and a second control valve disposed on the second pipe F and the third pipe E, respectively, by controlling the opening size or the spool of the first control valve and the second control valve, respectively. The position is to control the intake flow rate of the second pipe F and the third pipe E. Of course, the present invention is not limited thereto, and the control valve assembly 6 can also achieve the purpose of controlling the intake flow rate of the second pipe F and the third pipe E by controlling the pipe diameter ratio or the flow area ratio of the second pipe F and the third pipe E. .

When the refrigeration system 100 is operating in the cooling mode, at this time, the indoor heat exchanger 5 is a low-pressure side heat exchanger, the outdoor heat exchanger 3 is a high-pressure side heat exchanger, and the four-way valve 2 is controlled by flow direction to make the slave exhaust pipe The high-temperature and high-pressure gas discharged from D flows to the outdoor heat exchanger 3 for condensation heat exchange, and then enters the indoor heat exchanger 5 to cool the indoor environment through the throttling action of the throttling element 4, from the indoor heat exchanger 5 The low temperature and low pressure system return air flowing out of the outlet flows through the first pipe G to the control valve assembly 6, and the control valve assembly 6 controls the intake flow rate of the third pipe E to be larger than the intake flow rate of the second pipe F. In other words, the control valve assembly 6 makes The system return air is mainly connected to the direction of the intermediate suction pipe S2, wherein, specifically, the total flow rate of the system return air, that is, the intake flow rate in the first pipe G is v, and the flow rate v2 flowing to the intermediate suction pipe S2 is the third pipe. The ratio between the inspiratory flow rate v2 of E and the total flow rate V is v3: v3 ^ 0.6, and in some examples of the invention, v2 = v, ie, the inspiratory flow rate in the third conduit E is equal to the first conduit G Inspiratory flow inside, Completely inhale through an intermediate suction intake pipe S2.

At this time, the inhaled gas is mainly sucked through the intermediate suction pipe S2, and does not need to pass through the motor, thereby reducing the degree of heating of the suction gas by the motor, reducing the deterioration of performance due to heating, and allowing a small amount of gas to be sucked up from above. The air pipe S1 is sucked in, and the motor is cooled after passing through the motor to ensure the reliability of the motor. Under certain conditions of use, even if the upper suction pipe S1 has no gas suction, the temperature of the motor will not appear higher temperature due to the low temperature environment. At this time, the gas that can be inhaled is all from the middle suction pipe S2. Inhalation, the problem of lowering the performance of the suction by heating is prevented to the utmost, and the performance of the low back pressure rotary compressor 1 and the refrigeration system 100 is improved.

When the refrigeration system 100 is operating in the heating mode, at this time, the indoor heat exchanger 5 is a high-pressure side heat exchanger, the outdoor heat exchanger 3 is a low-pressure side heat exchanger, and the four-way valve 2 is controlled by flow direction to make the exhaust gas The high-temperature and high-pressure gas discharged from the tube D flows into the indoor heat exchanger 5 to heat the indoor environment, and then enters the outdoor through the throttling action of the throttling element 4. The heat exchanger 3 exchanges heat with the outside air, and finally the low temperature and low pressure system flowing out from the outlet of the outdoor heat exchanger 3 returns to the control valve assembly 6 through the first pipe G, and the second valve F of the control valve assembly 6 is sucked. The air flow is greater than the suction flow of the third conduit E, in other words, the control valve assembly 6 causes the system return air to primarily communicate to the direction of the upper intake pipe S1. Specifically, the total flow rate of the system return air is v, and the flow rate vl of the flow upward suction pipe S1, that is, the ratio of the suction flow rate v1 in the second pipe F to the total flow rate V is v4: v4^0.6, and In some examples of the invention, vl = _{v may be made} , i.e., the inspiratory flow rate in the second conduit F is equal to the inspiratory flow rate in the first conduit G, and the inhalation is completely drawn through the upper suction duct S1.

According to the refrigeration system 100 of the embodiment of the present invention, the control valve assembly 6 controls the intake flow rate of the third pipe E to be larger than the intake flow rate of the second pipe F when the refrigeration system 100 is in the cooling mode, and the control valve assembly 6 is in the refrigeration system 100. When in the heating mode, the intake flow rate of the second pipe F is controlled to be larger than the intake flow rate of the third pipe E, so that when the refrigeration system 100 is in the cooling mode, the inhaled gas is mainly sucked through the intermediate suction pipe S2, and does not need to pass through. The motor, thereby reducing the degree of heating of the suction gas by the motor, reducing the deterioration of performance due to heating, and allowing a small amount of gas to be sucked from the upper suction pipe S1, cooling the motor after passing through the motor, ensuring the reliability of the motor, and When the refrigeration system 100 is in the heating mode, the inhaled gas is mainly sucked through the upper suction pipe S1, and the motor is cooled by the motor to ensure the reliability of the motor to the utmost extent.

In a specific embodiment of the present invention, the control valve assembly 6 is connected to the four-way valve 2 to determine that the refrigeration system 100 is in a cooling mode or a heating mode according to the refrigerant flow direction of the four-way valve 2, specifically, as shown in FIG. The control valve assembly 6 monitors the refrigerant flow direction of the four-way valve 2 through the passage L. Of course, the invention is not limited thereto, and the control valve assembly 6 can also acquire the operating mode of the refrigeration system 100 by other means such as remote control signals or the like of the refrigeration system 100.

In the present embodiment, the refrigerant used in the refrigeration system 100 has the following properties: the heating capacity of the refrigerant in the low back pressure rotary compressor 1 when the evaporation temperature, the condensation temperature, and the subcooling condition are constant. Or energy efficiency rises as the degree of superheat increases. For example, when the refrigeration cycle with the same evaporating temperature, condensing temperature, and subcooling conditions is calculated, when the degree of superheat increases from 5 °C to 35 °C, the heating capacity or energy efficiency increases. Specifically, the refrigerant is one of R290, R134a, and R410A. Example 2:

The refrigeration system 100 according to an embodiment of the present invention, as shown in FIGS. 8 and 10, includes: a low back pressure rotary compressor 1, an outdoor heat exchanger 3, an indoor heat exchanger 5, a throttle element 4, and a control valve assembly 6. The refrigeration system 100 can only operate in a cooling mode, that is, the refrigeration system 100 is a single cold machine.

The low back pressure rotary compressor 1 includes a housing and a motor and a compression mechanism disposed in the housing. The upper portion of the housing is provided with an upper air suction pipe S1, and the middle portion of the housing is provided with an intermediate air suction pipe S2. There is also an exhaust pipe D. Which needs to be said It is to be understood that the specific structure and working principle of the low back pressure rotary compressor 1 are well known to those skilled in the art and will not be described in detail herein.

One end of the outdoor heat exchanger 3 is connected to the exhaust pipe D. One end of the indoor heat exchanger 5 is connected to the other end of the outdoor heat exchanger 3. The throttle element 4 is connected in series between the outdoor heat exchanger 3 and the indoor heat exchanger 5. Alternatively, the throttling element 4 is a capillary or solenoid valve.

The control valve assembly 6 is connected to the other end of the indoor heat exchanger 5, the upper suction pipe S1 and the intermediate suction pipe S2 through the first pipe G, the second pipe F and the third pipe E, that is, the control valve The other end of the assembly 6 and the indoor heat exchanger 5 is connected through the first pipe G, the control valve assembly 6 is connected to the upper suction pipe S1 through the second pipe F, and the control valve assembly 6 and the intermediate suction pipe S2 are passed through the third pipe E. Connected, the control valve assembly 6 controls the intake flow of the third conduit E to be greater than the intake flow of the second conduit F. Specifically, the control valve assembly 6 may be a three-way valve or a valve body respectively disposed on the second pipe F and the third pipe E, and at this time, the cross-sectional area of the second pipe F and the third pipe E may be controlled. The way to control the intake flow rate of the second pipe F and the third pipe E.

When the refrigeration system 100 is in operation, the indoor heat exchanger 5 is always used as a low-pressure side heat exchanger, and the outdoor heat exchanger 3 always operates as a high-pressure side heat exchanger, and the high-temperature and high-pressure gas discharged from the compressor enters the outdoor heat exchanger 3 After condensing, it passes through the throttling element 4 and then flows to the indoor heat exchanger 5 to evaporate heat to achieve the purpose of cooling. The system return flow from the indoor heat exchanger 5 is v, and enters the control valve assembly 6.

Since the working mode is always in the cooling mode, the system return air is mainly sucked through the intermediate suction pipe S2, wherein, specifically, the ratio of the intake flow rate v2 of the third pipe E to the intake flow rate V of the first pipe G is V3 0.6, In some examples of the invention, v2 = v, i.e., the inspiratory flow rate in the third conduit E is equal to the inspiratory flow rate in the first conduit G, at which time the inhalation is completely drawn through the intermediate suction duct S2.

Thus, according to the refrigeration system 100 of the embodiment of the present invention, the control valve assembly 6 controls the intake flow rate of the third pipe E to be larger than the intake flow rate of the second pipe F, and the inhaled gas is mainly sucked through the intermediate suction pipe S2 without passing through The motor reduces the degree of heating of the suction gas by the motor, reduces the deterioration of performance due to heating, and allows a small amount of gas to be sucked from the upper suction pipe S1, and the motor is cooled by the motor to ensure the reliability of the motor. Under certain conditions of use, even if the upper suction pipe S1 has no gas suction, the temperature of the motor will not appear higher temperature due to the low temperature environment. At this time, the gas that can be inhaled is all from the middle suction pipe S2. Inhalation, maximally avoids the problem of performance degradation caused by inhalation heating, improving the performance of the compressor and system.

In the present embodiment, the refrigerant used in the refrigeration system 100 has the following properties: the heating capacity of the refrigerant in the low back pressure rotary compressor 1 when the evaporation temperature, the condensation temperature, and the subcooling condition are constant. Or energy efficiency rises as the degree of superheat increases. For example, when the refrigeration cycle with the evaporating temperature, the condensing temperature, and the subcooling condition is constant, when the degree of superheat increases from 5 °C to 35 °C, the heating capacity or energy efficiency increases. Specifically, the refrigerant is R290, A heating system 200 provided with a low back pressure rotary compressor 1 according to an embodiment of the present invention, which optimizes the heating system using the above principle, is described with reference to Figs. 8 and 11 in R134a, R410A. 200 capacity or energy efficiency in heating mode.

As shown in FIGS. 8 and 11, a heating system 200 according to an embodiment of the present invention includes: a low back pressure rotary compressor 1, an indoor heat exchanger 5, an outdoor heat exchanger 3, a throttle element 4, and a control The valve assembly 6, the heating system 200 can only operate in a heating mode. In some embodiments of the invention, the heating system 200 is a heat pump water heater, and the indoor heat exchanger 5 is disposed in the water tank 9 for heating the water tank 9. Water.

The low back pressure rotary compressor 1 includes a housing and a motor and a compression mechanism disposed in the housing. The upper portion of the housing is provided with an upper air suction pipe S1, and the middle portion of the housing is provided with an intermediate air suction pipe S2. There is also an exhaust pipe D. Among them, it should be noted that the specific structure and working principle of the low back pressure rotary compressor 1 are well known to those skilled in the art and will not be described in detail herein.

One end of the indoor heat exchanger 5 is connected to the exhaust pipe D. One end of the outdoor heat exchanger 3 is connected to the other end of the indoor heat exchanger 5. The throttle element 4 is connected in series between the indoor changer and the outdoor heat exchanger 3. Optionally, the throttling element 4 is a capillary or solenoid valve.

The control valve assembly 6 is connected to the outdoor heat exchanger 3, the upper suction pipe S1 and the intermediate suction pipe S2 through the first pipe G, the second pipe F and the third pipe E, that is, the control valve assembly 6 and the outdoor The heat exchangers 3 are connected by a first pipe G, the control valve assembly 6 and the upper suction pipe S1 are connected by a second pipe F, and the control valve assembly 6 and the intermediate suction pipe S2 are connected by a third pipe E. The control valve assembly 6 can control the intake flow rate of the second pipe F and the third pipe E, and the control valve assembly 6 controls the intake flow rate of the second pipe F to be larger than the intake flow rate of the third pipe E. Specifically, the control valve assembly 6 may be a three-way valve or a valve body respectively disposed on the second pipe F and the third pipe E, and at this time, the cross-sectional area of the second pipe F and the third pipe E may be controlled. The way to control the inspiratory flow of the second pipe F and the third pipe E.

When the heating system 200 is in operation, the outdoor heat exchanger 3 is a low pressure side heat exchanger, the indoor heat exchanger 5 is a high pressure side heat exchanger, and the high temperature and high pressure gas discharged from the exhaust pipe D flows into the indoor heat exchanger 5 The water in the water tank 9 or the indoor environment is heated, and then through the throttling action of the throttling element 4, enters the outdoor heat exchanger 3 to exchange heat with the outside air, and finally flows out from the outlet of the outdoor heat exchanger 3 The low pressure system return airflow to the control valve assembly 6, the intake flow rate of the second conduit F of the control valve assembly 6 is greater than the intake flow rate of the third conduit E. In other words, the control valve assembly 6 causes the system return air to be primarily connected to the upper suction. Tube S1 direction. Specifically, the total flow rate of the system return air is v, and the flow rate vl of the flow up the intake pipe S1, that is, the ratio of the intake flow rate in the second pipe F to the total flow rate V is v4: V4^ 0.8, and in some examples of the present invention, vl=v, that is, the inspiratory flow rate in the second conduit F is equal to the inspiratory flow rate in the first conduit G, and the inhalation is completely inhaled through the upper intake pipe S1. .

According to the heating system 200 of the embodiment of the present invention, the control valve assembly 6 controls the intake flow rate of the second pipe F to be larger than the intake flow rate of the third pipe E, so that the suction air passes through the motor to cool the motor, thereby maximally securing the motor. reliability.

In the present embodiment, the refrigerant in the low back pressure rotary compressor 1 is a mixed refrigerant containing R32, and the mass percentage of R32 is 50% or less.

In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "illustrative embodiment", "example", "specific example", or "some examples", etc. Particular features, structures, materials or features described in the examples or examples are included in at least one embodiment or example of the invention. In the present specification, the schematic representation of the above terms does not necessarily mean the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples.

While the embodiments of the present invention have been shown and described, the embodiments of the invention may The scope of the invention is defined by the claims and their equivalents.

Claims

claims

1. A refrigeration system, characterized by including:

Low back pressure rotary compressor. The low back pressure rotary compressor includes a casing and a motor and a compression mechanism located in the casing. The upper part of the casing is provided with an upper suction pipe. The casing The middle part of the body is provided with an intermediate suction pipe, and the casing is also provided with an exhaust pipe;

Four-way valve, the four-way valve has an exhaust valve port, a suction valve port, an outdoor heat exchanger valve port and an indoor heat exchanger valve port, and the exhaust valve port is connected to the exhaust pipe;

An outdoor heat exchanger, one end of the outdoor heat exchanger is connected to the valve port of the outdoor heat exchanger;

Indoor heat exchanger, one end of the indoor heat exchanger is connected to the valve port of the indoor heat exchanger, and the other end of the indoor heat exchanger is connected to the other end of the outdoor heat exchanger;

A throttling element, the throttling element is connected in series between the outdoor heat exchanger and the indoor heat exchanger; a control valve assembly, the control valve assembly is connected with the suction valve port and the upper suction pipe The control valve assembly is connected to the intermediate suction pipe through a first pipe, a second pipe and a third pipe respectively. When the refrigeration system is in the refrigeration mode, the control valve assembly controls the suction flow of the third pipe to be greater than the The suction flow rate of the second pipe: when the refrigeration system is in the heating mode, the control valve assembly controls the suction flow rate of the second pipe to be greater than the suction flow rate of the third pipe.

2. The refrigeration system according to claim 1, wherein in the refrigeration mode, the ratio of the suction flow rate of the third pipe to the suction flow rate of the first pipe is greater than or equal to 0.6.

3. The refrigeration system according to claim 2, wherein in the refrigeration mode, the suction flow rate in the third pipe is equal to the suction flow rate in the first pipe.

4. The refrigeration system according to claim 1, wherein in the heating mode, the ratio of the suction flow rate of the second pipe to the suction flow rate of the first pipe is greater than or equal to 0.6.

5. The refrigeration system according to claim 4, wherein in the heating mode, the suction flow rate of the second pipe is equal to the suction flow rate of the first pipe.

6. The refrigeration system according to claim 1, wherein the control valve assembly includes a first control valve and a second control valve respectively provided on the second pipe and the third pipe.

7. The refrigeration system according to claim 1, wherein the control valve assembly is connected to the four-way valve to determine whether the refrigeration system is in cooling mode or heating based on the refrigerant flow direction of the four-way valve. model.

8. The refrigeration system according to claim 1, characterized in that, when the conditions of evaporation temperature, condensation temperature and subcooling remain unchanged, the heating capacity of the refrigerant in the low back pressure rotary compressor or Energy efficiency increases with superheat High and rising.

9. A refrigeration system, characterized by including:

An outdoor heat exchanger, one end of the outdoor heat exchanger is connected to the exhaust pipe;

Indoor heat exchanger, one end of the indoor heat exchanger is connected to the other end of the outdoor heat exchanger;

A throttling element, the throttling element is connected in series between the outdoor heat exchanger and the indoor heat exchanger; a control valve assembly, the control valve assembly is connected to the other end and the other end of the indoor heat exchanger. The above suction pipe and the intermediate suction pipe are connected through a first pipe, a second pipe and a third pipe, and the control valve assembly controls the suction flow of the third pipe to be greater than that of the second pipe. Inspiratory flow.

10. The refrigeration system according to claim 9, wherein the ratio of the suction flow rate of the third pipe to the suction flow rate of the first pipe is greater than or equal to 0.6.

11. The refrigeration system according to claim 10, wherein the suction flow rate of the third pipe is equal to the suction flow rate of the first pipe.

12. The refrigeration system according to claim 9, characterized in that, when the conditions of evaporation temperature, condensation temperature and subcooling remain unchanged, the heating capacity of the refrigerant in the low back pressure rotary compressor or Energy efficiency increases with increasing superheat.

13. The refrigeration system according to claim 12, characterized in that the refrigerant is one of R290, R134a, and R410A.

14. The refrigeration system according to claim 9, wherein the control valve assembly is a three-way valve.

15. A heating system, characterized by including:

Indoor heat exchanger, one end of the indoor heat exchanger is connected to the exhaust pipe;

An outdoor heat exchanger, one end of the outdoor heat exchanger is connected to the other end of the indoor heat exchanger;

A throttling element, the throttling element is connected in series between the indoor heat exchanger and the outdoor heat exchanger; a control valve assembly, the control valve assembly is connected with the outdoor heat exchanger, the upper suction pipe and the intermediate The suction pipes are respectively connected through a first pipe, a second pipe and a third pipe, and the control valve assembly controls the suction flow rate of the second pipe to be greater than the suction flow rate of the third pipe.

16. The heating system according to claim 15, wherein the ratio of the suction flow rate of the second pipe to the suction flow rate of the first pipe is greater than or equal to 0.8.

17. The heating system according to claim 16, wherein the suction flow rate of the second pipe is equal to the suction flow rate of the first pipe.

18. The heating system according to claim 15, wherein the refrigerant in the low back pressure rotary compressor is a mixed refrigerant containing R32, and the mass percentage of R32 is less than or equal to 50 %.

19. The heating system according to claim 15, wherein the control valve assembly is a three-way valve.

20. The heating system according to claim 15, wherein the heating system is a heat pump water heater, and the indoor heat exchanger is provided in a water tank for heating water in the water tank.