CN116877427A - Scroll compressor and pressure guiding and adjusting method and system thereof - Google Patents

Abstract

The invention belongs to the technical field of compressors and discloses a scroll compressor and a pressure regulating method and system thereof; the scroll compressor includes: a movable scroll, a fixed scroll, a back pressure chamber, a suction chamber, and an exhaust chamber. The air chamber, the pressure-inducing channel, the exhaust channel, the first throttle valve and the second throttle valve; wherein, the exhaust chamber passes through the pressure-inducing channel, the first throttle valve, the exhaust gas in sequence. The channel is connected to the back pressure chamber; the suction chamber passes through the second throttle valve in turn, and the exhaust channel is connected to the back pressure chamber; the opening of the first throttle valve can be tune. The invention discloses an innovative scroll compressor and a pressure adjustment method, which can effectively reduce the pressure pulsation of the working chamber during the compression process; the one-way real-time active adjustment of the back pressure can make the back pressure satisfy both the axial and axial pressure requirements. The requirement of sealing without excessively increasing the mechanical power of the compressor is crucial to ensuring the efficiency of the compressor.

Description

A scroll compressor and its pressure adjustment method and system

Technical field

The invention belongs to the technical field of compressors, and particularly relates to a scroll compressor and its pressure regulating method and system.

Background technique

Scroll compressors have the characteristics of high efficiency, low noise, and smooth operation, and are widely used in various air conditioning and heat pump systems; especially in the air conditioning systems of new energy vehicles, scroll compressors are the preferred solution. To further explain, the moving and stationary scrolls of the scroll compressor are affected by axial gas forces during the compression process. The back pressure in the back pressure chamber is often used to balance the axial gas forces to achieve axial sealing of the compressor. .

At present, the way to establish the back pressure in the back pressure chamber of a scroll compressor is generally to open a pressure guide hole on the base of the movable scroll. The pressure guide hole connects the working chamber and the back pressure chamber, and the working chamber pressure is used to establish the back pressure; existing The scroll compressors that adopt this solution generally have a single pressure-inducing hole. Since the pressure-inducing mechanism does not have a check function, the internal pressure pulsation of the working chamber where the pressure-inducing hole is opened is caused. To be specific and explanatory, for the CO ₂ new energy vehicle air conditioning system, the cycle often operates in the transcritical range, with high operating pressure and large pressure ratio. Due to the influence of the high operating pressure of the CO ₂ scroll compressor, the back pressure chamber back pressure The stability of the compressor is particularly important; under the high pressure and large pressure difference conditions of the transcritical CO ₂ cycle, the single pressure hole structure will aggravate the pressure fluctuations in the working chamber and seriously affect the efficiency of the compressor.

Contents of the invention

The object of the present invention is to provide a scroll compressor and its pressure regulating method and system to solve one or more of the above-mentioned technical problems. The technical solution provided by the present invention discloses an innovative scroll compressor and a pressure adjustment method, which can effectively reduce the pressure pulsation of the working chamber during the compression process; the back pressure can be actively adjusted in one direction in real time to reduce the back pressure. The pressure meets the requirements of axial sealing without excessively increasing the mechanical power of the compressor, which is crucial to ensuring the efficiency of the compressor.

In order to achieve the above objects, the present invention adopts the following technical solutions:

The invention provides a scroll compressor, which includes: a movable scroll, a fixed scroll, a back pressure chamber, a suction chamber and an exhaust chamber; and also includes: a pressure induction channel, an exhaust channel, a first throttle valve and a second throttle valve;

Wherein, the exhaust chamber is connected to the back pressure chamber through the pressure induction channel, the first throttle valve, and the exhaust channel in sequence; the suction chamber passes through the second throttling valve in sequence. The valve, the exhaust channel and the back pressure chamber are connected; the opening of the first throttle valve is adjustable.

A further improvement of the present invention is that the second throttle valve is set to a fixed opening.

A further improvement of the present invention is that both the first throttle valve and the second throttle valve adopt one-way solenoid valves.

A further improvement of the present invention is that the scroll compressor is used in a new energy vehicle air conditioning system.

The invention provides a pressure regulating method for a scroll compressor, which includes the following steps:

Get the exhaust pressure value;

Based on the obtained exhaust pressure value, calculate the instantaneous minimum back pressure value;

Optimally adjust the opening of the first throttle valve so that the back pressure value is close to the instantaneous minimum back pressure value; in the process of the back pressure value being close to the instantaneous minimum back pressure value, all The isentropic efficiency of the above-mentioned scroll compressor is optimized. When the isentropic efficiency reaches the maximum value, the corresponding back pressure value is the actual optimal back pressure value. The opening of the first throttle valve at this time is regarded as the optimal opening. degree to achieve pressure adjustment.

A further improvement of the present invention is that the calculation expression of the instantaneous minimum back pressure value is,

In the formula, P _min is the instantaneous minimum back pressure value, F _a is the axial gas force, M _t is the overturning moment, D _b and A _b are the outer edge diameter and back surface area of the orbiting scroll respectively;

The calculation expression of the axial gas force is,

In the formula, P _suc is the suction pressure, P is the involute pitch, A ₁ is the axial gas force action area of the central compression chamber, N is the number of involute coils, θ is the main axis angle, ρ _i is the i-th compression The compression ratio of the cavity.

A further improvement of the present invention is that the opening of the first throttle valve is optimized and adjusted so that the back pressure value is close to the instantaneous minimum back pressure value; the back pressure value is close to the instantaneous minimum back pressure value. In the process of compressing the pressure value, the isentropic efficiency of the scroll compressor is optimized. The corresponding back pressure value when the isentropic efficiency reaches the maximum value is the actual optimal back pressure value. Taking the first value at this time The throttle valve opening is regarded as the optimal opening, and the steps to achieve pressure adjustment include:

Read the initial value and calculate the isentropic efficiency η _is-0 ; where the initial value includes the suction temperature T _suc-0 of the scroll compressor, the suction pressure P _suc-0 , the exhaust temperature T _dis-0 , the exhaust gas Pressure P _dis-0 ;

Using Δd as the gradient, increase the opening of the first one-way solenoid valve, and read the suction temperature T _suc-1 , suction pressure P _suc-1 , exhaust temperature T _dis-1 , and exhaust pressure P _dis-1 , Calculate the isentropic efficiency η _is-1 , the change amount of the isentropic efficiency is Δη ₁ , Δη ₁ = η _is-1 - _{η is-0} ;

If Δη ₁ =0, record the back pressure value at this time as the optimal back pressure value; if Δη ₁ <0, use Δd as the gradient, reduce the opening of the first one-way solenoid valve, and read the suction pressure repeatedly. Air temperature T _suc-j , suction pressure P _suc-j , exhaust temperature T _dis-j , exhaust pressure P _dis-j , calculate isentropic efficiency η _is-j , and the change amount of isentropic efficiency is Δη _j , Δη _j ＝eta _is-j -η _is-j-1 , until Δη _j =0, record the back pressure value at this time as the optimal back pressure value; if Δη ₁ >0, then use Δd as the gradient, Increase the opening of the first one-way solenoid valve, repeatedly read the suction temperature T _suc-j , suction pressure P _suc-j , exhaust temperature T _dis-j , and exhaust pressure P _dis-j , and calculate the isentropic efficiency. η _is-j , the change amount of isentropic efficiency is Δη _j , Δη _j =η _is-j -η _is-j-1 , until Δη _j =0, the back pressure value recorded at this time is the optimal back pressure Pressure value.

The invention provides a pressure regulating system for a scroll compressor, including:

Data acquisition module, used to obtain exhaust pressure value;

A calculation module used to calculate and obtain the instantaneous minimum back pressure value based on the obtained exhaust pressure value;

Optimal adjustment module, used to optimally adjust the opening of the first throttle valve so that the back pressure value is close to the instantaneous minimum back pressure value; the back pressure value is close to the instantaneous minimum back pressure pressure In the process of value, the isentropic efficiency of the scroll compressor is optimized. When the isentropic efficiency reaches the maximum value, the corresponding back pressure value is the actual optimal back pressure value. Based on the first throttling at this time The valve opening is used as the optimal opening to achieve pressure regulation.

A further improvement of the present invention is that the calculation expression of the instantaneous minimum back pressure value is,

In the formula, P _min is the instantaneous minimum back pressure value, P _a is the axial gas force, M _t is the overturning moment, D _b and A _b are the outer edge diameter and back area of the orbiting scroll respectively;

The calculation expression of the axial gas force is,

In the formula, P _suc is the suction pressure, P is the involute pitch, A ₁ is the axial gas force action area of the central compression chamber, N is the number of involute coils, θ is the main axis angle, ρ _i is the i-th compression The compression ratio of the cavity.

A further improvement of the present invention is that the optimization adjustment module performs optimization adjustment of the opening of the first throttle valve so that the back pressure value is close to the instantaneous minimum back pressure value; the back pressure pressure When the value is close to the instantaneous minimum back pressure value, the isentropic efficiency of the scroll compressor is optimized. When the isentropic efficiency reaches the maximum value, the corresponding back pressure value is the actual optimal back pressure value. , taking the opening of the first throttle valve at this time as the optimal opening, the steps to achieve pressure adjustment include:

Read the initial value and calculate the isentropic efficiency η _is-0 ; where the initial value includes the suction temperature T _suc-0 of the scroll compressor, the suction pressure P _suc-0 , the exhaust temperature T _dis-0 , the exhaust gas Pressure P _dis-0 ;

Using Δd as the gradient, increase the opening of the first one-way solenoid valve, and read the suction temperature T _suc-1 , suction pressure P _suc-1 , exhaust temperature T _dis-1 , and exhaust pressure P _dis-1 , Calculate the isentropic efficiency η _is-1 , the change amount of the isentropic efficiency is Δη ₁ , Δη ₁ = η _is-1 - _{η is-0} ;

If Δη ₁ =0, record the back pressure value at this time as the optimal back pressure value; if Δη ₁ <0, use Δd as the gradient, reduce the opening of the first one-way solenoid valve, and read the suction pressure repeatedly. Air temperature T _suc-j , suction pressure P _suc-j , exhaust temperature T _dis-j , exhaust pressure P _dis-j , calculate isentropic efficiency η _is-j , and the change amount of isentropic efficiency is Δη _j , Δη _j ＝eta _is-j -η _is-j-1 , until Δη _j =0, record the back pressure value at this time as the optimal back pressure value; if Δη ₁ >0, then use Δd as the gradient, Increase the opening of the first one-way solenoid valve, repeatedly read the suction temperature T _suc-j , suction pressure P _suc-j , exhaust temperature T _dis-j , and exhaust pressure P _dis-j , and calculate the isentropic efficiency. η _is-j , the change amount of isentropic efficiency is Δη _j , Δη _j =η _is-j -η _is-j-1 , until Δη _j =0, the back pressure value recorded at this time is the optimal back pressure Pressure value.

Compared with the prior art, the present invention has the following beneficial effects:

In the prior art, for scroll compressors (exemplarily, especially scroll compressors for CO ₂ new energy vehicle air-conditioning systems), when axial sealing is achieved by introducing a back-pressure chamber structure, the working chamber pressure is affected and pressure occurs. Fluctuations, back pressure pressure pulsation and the inability to adjust in real time cause inconsistent fit between the dynamic and static scrolls of the compressor, which seriously affects the efficiency of the compressor. In view of the above situation, the present invention specifically discloses a scroll compressor. It adopts the method of inducing pressure directly from the exhaust chamber to the back pressure chamber, and by adding a throttle valve with a check function (specific explanation, the creative technical means of the present invention is to connect the exhaust chamber and the back pressure chamber. A pressure induction channel and a first throttle valve are added between the chambers, and an exhaust channel and a second throttle valve are added between the back pressure chamber and the suction chamber; the opening of the first throttle valve is used to adjust the diameter of the pressure induction connection. , thereby accurately controlling the back pressure) and achieving real-time control of the back pressure. In summary, the technical solution disclosed in the present invention not only avoids the impact of the back pressure on the working chamber pressure during the establishment process, but also can realize real-time regulation of the back pressure according to the operating conditions of the compressor. When the back pressure is adjusted to be close to the minimum back pressure, In the process of increasing pressure, the isentropic efficiency of the compressor is optimized in real time to ensure that the compressor is in the best efficiency state under any working conditions.

Further explanation of the present invention is that the first throttle valve is used to throttle the high-pressure working fluid gas directed from the exhaust chamber to the back pressure chamber through the pressure induction channel, and the opening of the throttle valve can be adjusted in real time. The second throttle valve is used to throttle the high-pressure working fluid gas directed from the back pressure chamber to the suction chamber through the exhaust channel, and the throttle valve has a fixed opening.

In the method of the present invention, the back pressure can be actively adjusted in real time, which can ensure that the compressor always operates at the best performance with maximum isentropic efficiency.

Description of the drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following is a brief introduction to the drawings that need to be used in the description of the embodiments or the prior art; obviously, the drawings in the following description are: For some embodiments of the present invention, those of ordinary skill in the art can also obtain other drawings based on these drawings without exerting creative efforts.

Figure 1 is a scroll compressor provided by an embodiment of the present invention;

Figure 2 is a schematic diagram of the simplified PID logic flow of active pressure adjustment in the embodiment of the present invention;

The reference numbers in the figures indicate,

1. First throttle valve; 2. Second throttle valve; 3. Moving scroll; 4. Fixed scroll; 5. Back pressure chamber; 6. Suction chamber; 7. Exhaust chamber; 8. Pressure induction Channel; 9. Exhaust channel.

Detailed ways

In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only These are some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts should fall within the scope of protection of the present invention.

It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It is to be understood that the data so used are interchangeable under appropriate circumstances so that the embodiments of the invention described herein are capable of being practiced in sequences other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, e.g., a process, method, system, product, or apparatus that encompasses a series of steps or units and need not be limited to those explicitly listed. Those steps or elements may instead include other steps or elements not expressly listed or inherent to the process, method, product or apparatus.

The present invention will be described in further detail below in conjunction with the accompanying drawings:

Referring to Figure 1, a scroll compressor provided by an embodiment of the present invention includes: a first throttle valve 1, a second throttle valve 2, an orbiting scroll 3, a fixed scroll 4, a back pressure chamber 5, a suction Air chamber 6, exhaust chamber 7, pressure induction channel 8 and exhaust channel 9;

Among them, the exhaust chamber 7 is connected to the back pressure chamber 5 through the pressure induction channel 8, the first throttle valve 1, and the exhaust channel 9 in sequence; the suction chamber 6 passes through The second throttle valve 2, the exhaust passage 9 and the back pressure chamber 5 are connected; the opening of the first throttle valve 1 is adjustable; further preferably, the second throttle valve 2 is used to set a fixed opening.

In the technical solution provided by the embodiment of the present invention, the pressure induction method is one-way pressure induction from the back pressure chamber without opening a pressure induction hole; a pressure induction channel 8 and a first throttle valve are added between the exhaust chamber 7 and the back pressure chamber 5 1. Add an exhaust channel 9 and a second throttle valve 2 between the back pressure chamber 5 and the suction chamber 6; the opening of the first throttle valve 1 is used to adjust the diameter of the pressure-induction communication to accurately control the back pressure. pressure; in addition, the second throttle valve 2 can be set to a fixed opening (the second throttle valve 2 does not participate in the active adjustment function. If the pressure in the back pressure chamber is too high, it is used for pressure relief, which can be understood as the back pressure chamber. An outlet channel of the pressure chamber 5; if it is set to have an adjustable opening, it will increase the processing and design cost and is unnecessary).

The embodiments of the present invention are further illustrative,

The movable scroll 3 is a scroll that always keeps moving during the operation of the scroll compressor. It is driven by the rotation of the main shaft to perform translational motion and is used to mesh with the fixed scroll 4 to form a closed working chamber of the compressor and compress the working fluid. gas;

The fixed scroll 4 is a scroll that always remains stationary during the operation of the scroll compressor. It is used to mesh with the movable scroll 3 to form a closed working chamber of the compressor and compress the working gas;

The back pressure chamber 5 is a closed cavity surrounded by the movable scroll 3 and the bearing seat, and is used to provide the axial back pressure of the movable scroll 3 and balance the gas force, so that the movable scroll 3 is in an appropriate stress state;

The suction chamber 6 refers to the cavity of the compressor used to absorb low-pressure working fluid;

The exhaust chamber 7 refers to the chamber of the compressor used to discharge the high-pressure working fluid gas compressed by the working chamber.

In the embodiment of the present invention, the first throttle valve 1 is used to throttle the high-pressure working fluid gas guided from the exhaust chamber 7 through the pressure induction channel 8 to the back pressure chamber 5, and the opening of the throttle valve can achieve real-time Regulation. To further explain, by reading real-time working condition parameters, based on PID negative feedback adjustment and automatic optimization control methods, the throttle valve opening is adjusted in real time to achieve the optimal back pressure value of the back pressure chamber pressure, and the compressor isentropic efficiency at its maximum.

In the embodiment of the present invention, the second throttle valve 2 is used to throttle the high-pressure working fluid gas directed from the back pressure chamber 5 to the suction chamber 6 through the exhaust channel 9, and the throttle valve has a fixed opening.

As a specific example of the embodiment of the present invention, both the first throttle valve 1 and the second throttle valve 2 may use one-way solenoid valves.

The scroll compressor provided by the embodiment of the present invention can be used as a scroll compressor in a new energy vehicle air conditioner; further illustratively, for a CO ₂ new energy vehicle air conditioning system, the cycle often operates in a transcritical range, and the operating pressure is high, The pressure ratio is large. Due to the influence of high operating pressure of the _CO2 scroll compressor, the stability of the backpressure pressure in the back pressure chamber is particularly important; and under the high pressure and large pressure difference conditions of the transcritical _CO2 cycle, the single pressure hole is The structure will aggravate the pressure fluctuations in the working chamber and seriously affect the efficiency of the compressor. The introduced pressure inducing method of the present invention can effectively reduce the pressure pulsation of the working chamber during the compression process, and perform one-way real-time active adjustment of the back pressure, so that the back pressure can meet the requirements of axial sealing without being excessive. Increasing the mechanical power of the compressor is crucial to ensuring the efficiency of the compressor.

An embodiment of the present invention provides a pressure adjustment method for a scroll compressor, which includes the following steps:

S1: Get the real-time exhaust pressure value P _dis ;

S2: Based on the exhaust pressure value P _dis obtained in step S1, calculate the instantaneous minimum back pressure value P _min ;

S3: Optimize and adjust the opening of the first throttle valve 1 so that the real-time back pressure value is close to the instantaneous minimum back pressure value P _min . During the process, the isentropic efficiency of the compressor is optimized in real time. When the isentropic efficiency reaches The corresponding back pressure at the maximum value is the actual optimal back pressure value. It is determined that the opening of the first throttle valve 1 at this time is the optimal opening, and the pressure adjustment is completed.

The pressure adjustment method provided by the embodiment of the present invention achieves the purpose of real-time regulation of the back pressure by adding a throttle valve with a check function, which not only avoids the impact of the back pressure establishment process on the working chamber pressure, but also can adjust the pressure according to the compression It realizes real-time negative feedback adjustment of back pressure according to the operating conditions of the machine, ensuring that the compressor always operates at the best performance with maximum isentropic efficiency under any operating conditions.

Please refer to Figure 2 for further explanation. During the adjustment process, the suction temperature, suction pressure, discharge temperature, and discharge pressure of the compressor are collected in real time to calculate the back pressure value of the compressor and the pressure of the compressor in real time. The isentropic efficiency, in which the real-time back pressure value is used as the input quantity of the negative feedback PID control adjustment, and the output quantity is the opening of the first single throttle valve; the real-time isentropic efficiency value is used as the input quantity of real-time optimization. When the back pressure approaches the minimum back pressure, the isentropic efficiency of the compressor is optimized in real time. When the isentropic efficiency reaches the maximum value, the corresponding back pressure at this time is the actual optimal back pressure value.

In step 2 of the embodiment of the present invention, the size of the back pressure is determined by the real-time stress condition of the movable scroll. The minimum back pressure reference value (P _min ) is usually based on the back pressure, axial gas force (F _a ) and overturning moment. (M _t ) to determine, its calculation expression is:

In the formula, D _b and A _b are the outer edge diameter and back surface area of the orbiting scroll respectively;

The calculation method of axial gas force is as follows:

In the formula, P _suc is the suction pressure, P is the involute pitch, A ₁ is the axial gas force action area of the central compression chamber, N is the number of involute coils, θ is the main axis angle, ρ _i is the i-th compression The compression ratio of the cavity.

Principle explanation of the embodiment of the present invention: It can be seen from the above calculation that the axial gas force has pulsation, so the pressure adjustment is pulsation adjustment; the function of the minimum back pressure value is to limit the range of isentropic efficiency optimization to ensure that the sought Isentropic efficiency is a maximum value rather than a maximum value.

Please refer to Figure 2. In the embodiment of the present invention, the back pressure adjustment is a double-layer control that combines real-time negative feedback PID control and automatic optimization control; wherein,

The negative feedback PID control is the bottom control. The input of the controller is the real-time back pressure, and the output is the opening of the first one-way solenoid valve; the target reference value in the early stage of control is the calculated instantaneous minimum back pressure value. , the target reference value in the later stage of control is the back pressure value obtained by automatic optimization; the overshoot of the back pressure pressure σ _P during the adjustment process satisfies: σ _P ≤ σ _max , where σ _max is determined by the maximum leakage of the compressor. Explanation, the early stage of control refers to calculating the real-time back pressure through real-time collected data, and controlling the opening of the first throttle valve through PID negative feedback adjustment to achieve the back pressure reaching the minimum back pressure value; its function is Limit the range of isentropic efficiency optimization in the later stage of control to ensure that the optimal isentropic efficiency value is the maximum value rather than the maximum value. The later stage of control refers to automatic optimization to control the isentropic efficiency of the compressor to the maximum isentropic efficiency.

In the embodiment of the present invention, the steps of the automatic optimization process are as follows:

S1: Read the initial values, the suction temperature T _suc-0 of the compressor, the suction pressure P _suc-0 , the exhaust temperature T _dis-0 , and the exhaust pressure P _dis-0 , and calculate the isentropic efficiency η _is-0 ;

S2: Using Δd as the gradient, increase the opening of the first one-way solenoid valve, and read the suction temperature T _suc-1 , suction pressure P _suc-1 , exhaust temperature T _dis-1 , and exhaust pressure P _{dis- 1} . Calculate the isentropic efficiency η _is-1 , and the change amount of the isentropic efficiency is Δη ₁ , which satisfies: Δη ₁ = η _is-1 - _{η is-0} .

If Δη ₁ =0, then the back pressure P _b recorded at this time is the optimal back pressure value.

If Δη ₁ <0, use Δd as the gradient, reduce the opening of the first one-way solenoid valve, and repeatedly read the suction temperature T _suc-j , suction pressure P _suc-j , exhaust temperature T _dis-j , Exhaust pressure P _dis-j . Calculate the isentropic efficiency η _is-j , and the change amount of the isentropic efficiency is Δη _j , which satisfies: Δη _j =η _is-j -η _is-j-1 . Until Δη _j =0, the back pressure P _b recorded at this time is the optimal back pressure value.

If Δη ₁ > 0, use Δd as the gradient, increase the opening of the first one-way solenoid valve, and repeatedly read the suction temperature T _suc-j , suction pressure P _suc-j , exhaust temperature T _dis-j , Exhaust pressure P _dis-j . Calculate the isentropic efficiency η _is-j , and the change amount of the isentropic efficiency is Δη _j , which satisfies: Δη _j =η _is-j -η _is-j-1 . Until Δη _j =0, the back pressure P _b recorded at this time is the optimal back pressure value.

To sum up, there are currently two main methods for establishing pressure in the back pressure chamber of scroll compressors. One is to open a pressure hole in the high-pressure chamber on the back of the static scroll, and use the high-pressure chamber pressure to establish the back pressure; A pressure-inducing hole is provided on the base of the orbiting scroll, which connects the working chamber and the back-pressure chamber, and uses the working chamber pressure to establish back-pressure. Scroll compressors using the first solution generally have a complicated structure and require a separate oil return channel for the working chamber. However, existing scroll compressors using the second solution generally have a single pressure hole. Since the pressure inducing mechanism does not have a non-return function, the pressure inside the working chamber where the pressure inducing hole is opened causes pressure pulsation. And it cannot be actively adjusted, and it cannot guarantee that the back pressure is the best choice under all working conditions. Especially under the high pressure and high pressure difference conditions involved in the transcritical _CO2 cycle, the pressure fluctuations in the working chamber are aggravated and seriously affect the efficiency and reliability of the compressor.

The inventive point of the technical solution of the present invention is that it belongs to the field of compressor technology and relates to the field of scroll compressors for new energy vehicle air conditioners. Specifically, an active pressure design and pressure adjustment of a scroll compressor for new energy vehicle air conditioners are disclosed. Method; the pressure induction method is one-way pressure induction in the back pressure chamber without opening a pressure induction hole. A pressure induction channel and a first one-way solenoid valve are added between the exhaust chamber and the back pressure chamber. An exhaust channel and a second one-way solenoid valve are added between the body and the suction cavity; the opening of the first one-way solenoid valve is used to adjust the diameter of the pressure connection to accurately control the back pressure. The one-way solenoid valve has a fixed opening. The pressure adjustment step is to first read the real-time exhaust pressure value P _dis , then calculate the instantaneous minimum back pressure value P _min , and finally adjust the opening of the first one-way solenoid valve so that the back pressure gradually approaches the minimum back pressure. pressure reference value; in the process of adjusting the back pressure gradually approaching the minimum back pressure, the isentropic efficiency of the compressor is optimized in real time. When the isentropic efficiency reaches the maximum value, the corresponding back pressure is the actual optimal back pressure. pressure value. The invention is applied to the active pressure regulation of a scroll compressor to improve the efficiency of the compressor. The invention adopts an active and adjustable one-way pressure inducing method that combines an additional pressure inducing channel and a solenoid valve. It has a check function, can avoid pressure fluctuations in the working chamber, and can perform real-time negative feedback adjustment of the back pressure to ensure the compressor Always run at optimal performance with maximum isentropic efficiency. The active pressure induction design of the scroll compressor and the pressure induction adjustment method provided by the embodiments of the present invention can actively adjust the back pressure of the scroll compressor of the new energy vehicle air conditioner in real time to ensure the efficiency of the compressor.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that the present invention can still be modified. Modifications or equivalent substitutions may be made to the specific embodiments, and any modifications or equivalent substitutions that do not depart from the spirit and scope of the invention shall be covered by the scope of the claims of the invention.

Claims (10)

1. A scroll compressor, including: an orbiting scroll (3), a fixed scroll (4), a back pressure chamber (5), a suction chamber (6) and an exhaust chamber (7), characterized by: Also includes: pressure induction channel (8), exhaust channel (9), first throttle valve (1) and second throttle valve (2); Wherein, the exhaust chamber (7) is connected to the back pressure chamber (5) through the pressure induction channel (8), the first throttle valve (1), and the exhaust channel (9). The suction chamber (6) is connected to the back pressure chamber (5) through the second throttle valve (2) and the exhaust passage (9) in sequence; the first throttle valve The opening of (1) is adjustable. 2. A scroll compressor according to claim 1, characterized in that the second throttle valve (2) is set to a fixed opening. 3. A scroll compressor according to claim 1, characterized in that both the first throttle valve (1) and the second throttle valve (2) adopt one-way solenoid valves. 4. A scroll compressor according to claim 1, characterized in that the scroll compressor is used in a new energy vehicle air conditioning system. 5. A pressure regulating method for a scroll compressor according to claim 1, characterized in that it includes the following steps: Get the exhaust pressure value; Based on the obtained exhaust pressure value, calculate the instantaneous minimum back pressure value; Optimally adjust the opening of the first throttle valve so that the back pressure value is close to the instantaneous minimum back pressure value; in the process of the back pressure value being close to the instantaneous minimum back pressure value, all The isentropic efficiency of the above-mentioned scroll compressor is optimized. When the isentropic efficiency reaches the maximum value, the corresponding back pressure value is the actual optimal back pressure value. The opening of the first throttle valve at this time is regarded as the optimal opening. degree to achieve pressure adjustment. 6. The pressure regulating method according to claim 5, characterized in that the calculation expression of the instantaneous minimum back pressure value is, In the formula, P _min is the instantaneous minimum back pressure value, F _a is the axial gas force, M _t is the overturning moment, D _b and A _b are the outer edge diameter and back surface area of the orbiting scroll respectively; The calculation expression of the axial gas force is, In the formula, P _suc is the suction pressure, P is the involute pitch, A ₁ is the axial gas force action area of the central compression chamber, N is the number of involute coils, θ is the main axis angle, ρ _i is the i-th compression The compression ratio of the cavity. 7. The pressure regulating method according to claim 5, wherein the optimization adjusts the opening of the first throttle valve so that the back pressure value is close to the instantaneous minimum back pressure value; When the back pressure value approaches the instantaneous minimum back pressure value, the isentropic efficiency of the scroll compressor is optimized. When the isentropic efficiency reaches the maximum value, the corresponding back pressure value is the actual optimal value. For the back pressure value, the opening of the first throttle valve at this time is taken as the optimal opening. The steps to realize the pressure adjustment include: Read the initial value and calculate the isentropic efficiency η _is-0 ; where the initial value includes the suction temperature T _suc-0 of the scroll compressor, the suction pressure P _suc-0 , the exhaust temperature T _dis-0 , the exhaust gas Pressure P _dis-0 ; Using Δd as the gradient, increase the opening of the first one-way solenoid valve, and read the suction temperature T _suc-1 , suction pressure P _suc-1 , exhaust temperature T _dis-1 , and exhaust pressure P _dis-1 , Calculate the isentropic efficiency η _is-1 , the change amount of the isentropic efficiency is Δη ₁ , Δη ₁ = η _is-1 - _{η is-0} ; If Δη ₁ =0, record the back pressure value at this time as the optimal back pressure value; if Δη ₁ <0, use Δd as the gradient, reduce the opening of the first one-way solenoid valve, and read the suction pressure repeatedly. Air temperature T _suc-j , suction pressure P _suc-j , exhaust temperature T _dis-j , exhaust pressure P _dis-j , calculate isentropic efficiency η _is-j , and the change amount of isentropic efficiency is Δη _j , Δη _j =η _is-j -η _is-j-1 until Δη _j =0, record the back pressure value at this time as the optimal back pressure value; if Δη ₁ >0, use Δd as the gradient, Increase the opening of the first one-way solenoid valve, repeatedly read the suction temperature T _suc-j , suction pressure P _suc-j , exhaust temperature T _dis-j , and exhaust pressure P _dis-j , and calculate the isentropic efficiency. η _is-j , the change amount of isentropic efficiency is Δη _j , Δη _j =η _is-j -η _is-j-1 , until Δη _j =0, the back pressure value recorded at this time is the optimal back pressure Pressure value. 8. A pressure regulating system for a scroll compressor according to claim 1, characterized in that it includes: Data acquisition module, used to obtain exhaust pressure value; A calculation module used to calculate and obtain the instantaneous minimum back pressure value based on the obtained exhaust pressure value; Optimal adjustment module, used to optimally adjust the opening of the first throttle valve so that the back pressure value is close to the instantaneous minimum back pressure value; the back pressure value is close to the instantaneous minimum back pressure pressure In the process of value, the isentropic efficiency of the scroll compressor is optimized. When the isentropic efficiency reaches the maximum value, the corresponding back pressure value is the actual optimal back pressure value. Based on the first throttling at this time The valve opening is used as the optimal opening to achieve pressure regulation. 9. The pressure regulating system according to claim 8, wherein the calculation expression of the instantaneous minimum back pressure value is, In the formula, P _min is the instantaneous minimum back pressure value, F _a is the axial gas force, M _t is the overturning moment, D _b and A _b are the outer edge diameter and back surface area of the orbiting scroll respectively; The calculation expression of the axial gas force is, In the formula, P _suc is the suction pressure, P is the involute pitch, A ₁ is the axial gas force action area of the central compression chamber, N is the number of involute coils, θ is the main axis angle, ρ _i is the i-th compression The compression ratio of the cavity. 10. The pressure regulating system according to claim 8, characterized in that the optimal adjustment module performs optimal adjustment of the opening of the first throttle valve so that the back pressure value is close to the instantaneous pressure value. Minimum back pressure value; when the back pressure value is close to the instantaneous minimum back pressure value, the isentropic efficiency of the scroll compressor is optimized, and the corresponding back pressure is obtained when the isentropic efficiency reaches the maximum value. The pressure value is the actual optimal back pressure value. Taking the opening of the first throttle valve at this time as the optimal opening, the steps to achieve pressure adjustment include: Read the initial value and calculate the isentropic efficiency η _is-0 ; where the initial value includes the suction temperature T _suc-0 of the scroll compressor, the suction pressure P _suc-0 , the exhaust temperature T _dis-0 , the exhaust gas Pressure P _dis-0 ; Using Δd as the gradient, increase the opening of the first one-way solenoid valve, and read the suction temperature T _suc-1 , suction pressure P _suc-1 , exhaust temperature T _dis-1 , and exhaust pressure P _dis-1 , Calculate the isentropic efficiency η _is-1 , the change amount of the isentropic efficiency is Δη ₁ , Δη ₁ = η _is-1 - _{η is-0} ; If Δη ₁ =0, record the back pressure value at this time as the optimal back pressure value; if Δη ₁ <0, use Δd as the gradient, reduce the opening of the first one-way solenoid valve, and read the suction pressure repeatedly. Air temperature T _suc-j , suction pressure P _suc-j , exhaust temperature T _dis-j , exhaust pressure P _dis-j , calculate isentropic efficiency η _is-j , and the change amount of isentropic efficiency is Δη _j , Δη _j =η _is-j -η _is-j-1 until Δη _j =0, record the back pressure value at this time as the optimal back pressure value; if Δη ₁ >0, use Δd as the gradient, Increase the opening of the first one-way solenoid valve, repeatedly read the suction temperature T _suc-j , suction pressure P _suc-j , exhaust temperature T _dis-j , and exhaust pressure P _dis-j , and calculate the isentropic efficiency. η _is-j , the change amount of isentropic efficiency is Δη _j , Δη _j =η _is-j -η _js-j-1 , until Δη _j =0, the back pressure value recorded at this time is the optimal back pressure Pressure value.