Flash economizers, chillers and air conditioning systems

Abstract

The present invention relates to the technical field of refrigeration equipment, and more specifically, to a flash economizer, a chiller, and an air conditioning system. The flash economizer includes an economizer body provided with an economizer liquid inlet, an economizer air inlet, and an economizer exhaust port. The economizer liquid inlet and the economizer air inlet are respectively used to introduce liquid refrigerant and gaseous refrigerant into the economizer body, causing the two to mix and establish a certain pressure within the economizer body, so that the gaseous refrigerant at a certain pressure can be discharged through the economizer exhaust port to replenish air for the two-stage compressor. This allows the feed amounts of liquid refrigerant and gaseous refrigerant to be individually controlled and adjusted to obtain different exhaust pressures, i.e., replenishment pressures. At the same time, the exhaust volume of the gaseous refrigerant can be adjusted and controlled by adjusting the opening of the economizer exhaust port, thereby enabling the flash economizer of the present application to adjust both the exhaust pressure and the exhaust volume.

Description

Technical Field

[0001] The present invention relates to the technical field of refrigeration equipment, and in particular to a flash economizer, a chiller and an air-conditioning system. Background Art

[0002] Two-stage centrifugal compressors are widely used in chillers. When the two-stage centrifugal compressor is in operation, under the designed working conditions, the two-stage centrifugal compressor can usually better balance the pressure between the first-stage compression pressure and the second-stage compression pressure, so that the unit operates in the optimal state; but with the changes in load and working conditions, there will often be a pressure imbalance problem in which the intermediate pressure is too high or too low. Due to the limited adjustment range of the throttling component, it is difficult to correct this pressure imbalance problem, causing the two-stage centrifugal compressor to deviate from the optimal operating point, reducing the operating energy efficiency of the chiller; at the same time, under certain working conditions, the centrifuge will also surge during operation. The usual way to solve the pressure imbalance and surge problems of the centrifuge is to add air to the compressor through an economizer, but the existing economizer cannot accurately control the air supply volume and air supply pressure, which affects the air supply effect. Summary of the Invention

[0003] The object of the present invention is to provide a flash economizer, a chiller and an air conditioning system, so as to accurately control the air supply pressure and air supply volume of the economizer.

[0004] The present invention provides a flash economizer, comprising an economizer body, wherein the economizer body is provided with:

[0005] an economizer liquid inlet, for introducing liquid refrigerant into the economizer body;

[0006] an economizer air inlet, for introducing gaseous refrigerant into the economizer body;

[0007] The economizer exhaust port is used to discharge the liquid refrigerant and the gaseous refrigerant flashed out in the economizer body.

[0008] Furthermore, a pressure detection device is provided at the exhaust port of the economizer.

[0009] Furthermore, the economizer air inlet is provided with an air intake flow regulating valve, and the air intake flow regulating valve is communicatively connected to the pressure detection device.

[0010] Furthermore, the economizer liquid inlet is provided with a liquid inlet flow regulating valve, and the liquid inlet flow regulating valve is communicatively connected to the pressure detection device.

[0011] Furthermore, the liquid inlet of the economizer is also provided with a throttling orifice plate, and the throttling orifice plate is connected in parallel with the liquid inlet flow regulating valve.

[0012] Furthermore, the economizer exhaust port is provided with an exhaust flow regulating valve, and the exhaust flow regulating valve is communicatively connected to the pressure detection device.

[0013] Furthermore, a disperser is provided in the economizer body;

[0014] The disperser is communicated with the air inlet of the economizer, and a plurality of gas dispersion ports are provided on the disperser.

[0015] Furthermore, the disperser is a nozzle.

[0016] Furthermore, a mixing chamber in communication with the economizer body is provided in the economizer body, and the economizer air inlet and the economizer liquid inlet are located in the mixing chamber.

[0017] Furthermore, a partition is provided in the economizer body, and the partition divides the economizer body into a first chamber located at the bottom and a second chamber located at the top;

[0018] The economizer liquid inlet and the economizer air inlet are in communication with the first chamber, and the economizer body is further provided with an economizer liquid discharge port in communication with the first chamber for discharging liquid refrigerant in the first chamber;

[0019] The partition is provided with a vent, through which the gaseous refrigerant flashed out of the first chamber can enter the second chamber, and the vent is provided with a filter for filtering the gaseous refrigerant;

[0020] The economizer exhaust port is communicated with the second chamber.

[0021] The present invention also provides a chiller, comprising any one of the flash economizers described above;

[0022] The chiller also includes a two-stage centrifugal compressor, a condenser and an evaporator;

[0023] The exhaust port of the two-stage centrifugal compressor is connected to the refrigerant inlet of the condenser;

[0024] The gaseous refrigerant outlet of the condenser is connected to the air inlet of the economizer, and the liquid refrigerant outlet of the condenser is connected to the liquid inlet of the economizer;

[0025] The economizer exhaust port is connected to the air supply port of the two-stage centrifugal compressor, and the economizer liquid discharge port formed by the flash economizer is connected to the inlet of the evaporator;

[0026] The exhaust port of the evaporator is communicated with the air inlet of the two-stage centrifugal compressor.

[0027] The present invention also provides an air-conditioning system, comprising the above-mentioned chiller.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] The flash economizer provided by the present invention includes an economizer body, which is provided with an economizer liquid inlet, an economizer air inlet and an economizer exhaust port, and the economizer liquid inlet, the economizer air inlet and the economizer exhaust port are respectively connected to the economizer body. The economizer liquid inlet is used to communicate with the liquid refrigerant supply equipment so that liquid refrigerant can be introduced into the economizer body; the economizer air inlet is used to communicate with the gaseous refrigerant supply equipment so that gaseous refrigerant can be introduced into the economizer body, so that the gaseous refrigerant and liquid refrigerant can be mixed in the economizer body; the gaseous refrigerant and liquid refrigerant in the economizer body will eventually separate into gas and liquid phases, forming liquid refrigerant with a certain liquid level below the economizer body and gaseous refrigerant filling the gas phase space above the liquid refrigerant; the economizer exhaust port provided on the economizer body is connected to the gas phase space within the economizer body, so that the gaseous refrigerant in the economizer body can be discharged from the economizer body through the economizer exhaust port, so as to be used to replenish air to the secondary impeller of the two-stage compressor. By providing independent economizer air inlets and liquid inlets on the economizer body, the gaseous refrigerant feed and liquid refrigerant feed of the economizer body do not interfere with each other. The gaseous refrigerant can enter the economizer body through the economizer air inlet via independent delivery pipes, and the liquid refrigerant can also enter the economizer body through the economizer liquid inlet via independent delivery pipes. This allows the liquid and gaseous refrigerant feed rates of the economizer body to be independently controlled, allowing the liquid and gaseous refrigerants to mix in different proportions within the economizer body, thereby changing the internal pressure of the economizer body to achieve different economizer body exhaust pressures and achieve regulation of the economizer body exhaust pressure. Furthermore, the exhaust volume of the gaseous refrigerant from the economizer body can be adjusted and controlled by controlling the opening of the economizer exhaust port, thereby enabling the flash economizer of the present application to regulate both the exhaust pressure and the exhaust volume.

[0030] The present invention also provides a chiller, including the flash economizer, and the chiller also includes a two-stage centrifugal compressor (two-stage compressor), a condenser and an evaporator; the refrigerant can circulate between the two-stage centrifugal compressor (two-stage compressor), the condenser, the evaporator and the flash economizer; the chiller includes the flash economizer, so the chiller also has the beneficial effects of the flash economizer, so that the chiller operates efficiently.

[0031] The present invention also provides an air-conditioning system comprising the chiller, so that the air-conditioning system also has the beneficial effects of the chiller. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0033] Figure 1 A schematic diagram of a chiller provided in an embodiment of the present invention;

[0034] Figure 2 Schematic diagram of a flash economizer according to an embodiment of the present invention.

[0035] In the picture:

[0036] 1-Flash economizer, 11-Economizer body, 12-Partitioner, 13-Vent, 14-Filter, 15-Economizer liquid inlet, 16-Economizer air inlet, 17-Economizer exhaust, 18-Economizer drain, 19-Mixing chamber, 110-Disperser, 111-Inlet flow regulating valve, 112-Inlet flow regulating valve, 113-Exhaust flow regulating valve, 114-Throttling orifice, 2-Two-stage compressor, 21-Reflux channel, 3-Condenser, 4-Evaporator. DETAILED DESCRIPTION

[0037] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0038] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are intended to fall within the scope of protection of the present invention.

[0039] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not require further definition or explanation in subsequent drawings.

[0040] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer" and the like indicate positions or locations based on the positions shown in the accompanying drawings, or the positions or locations in which the inventive product is typically placed when in use. These terms are intended solely to facilitate the description of the present invention and to simplify the description, and are not intended to indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third," etc., are used solely to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0041] Furthermore, terms such as "horizontal," "vertical," and "overhanging" do not necessarily imply that a component must be absolutely horizontal or overhanging, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but rather that it can be slightly tilted.

[0042] In the description of the present invention, it should also be noted that, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to mechanical connections or electrical connections; they may refer to direct connections or indirect connections through an intermediate medium; and they may refer to internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0043] The following combination Figure 1 and Figure 2 , some embodiments of the present invention are described in detail. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0044] The present application provides a flash economizer 1 for a chiller to replenish air to a two-stage centrifugal compressor (hereinafter referred to as the two-stage compressor 2) in the chiller. Figure 2 As shown, the flash economizer 1 includes an economizer body 11, which is provided with an economizer liquid inlet 15, an economizer air inlet 16, and an economizer exhaust port 17. The economizer liquid inlet 15, the economizer air inlet 16, and the economizer exhaust port 17 are respectively connected to the economizer body 11. The locations of the economizer liquid inlet 15, the economizer air inlet 16, and the economizer exhaust port 17 are not particularly limited, as long as the economizer liquid inlet 15, the economizer air inlet 16, and the economizer exhaust port 17 are respectively connected to the economizer body 11.

[0045] In this embodiment, the economizer liquid inlet 15 is used to communicate with the liquid refrigerant feeding device so that the liquid refrigerant can be introduced into the economizer body 11; for example, in a chiller, combined with Figure 1 As shown, the chiller includes a condenser 3, which is used to condense the gaseous refrigerant discharged from the two-stage compressor 2. A liquid refrigerant outlet is provided on the condenser 3, and the liquid refrigerant condensed in the condenser 3 can be discharged through the liquid refrigerant outlet of the condenser 3; the economizer liquid inlet 15 is connected to the liquid refrigerant outlet of the condenser 3, so that the liquid refrigerant in the condenser 3 can flow into the economizer body 11 through the pipeline connecting the economizer liquid inlet 15 and the liquid refrigerant outlet of the condenser 3, so as to be flash evaporated in the economizer body 11.

[0046] The economizer air inlet 16 is used to communicate with the gaseous refrigerant feed equipment so that the gaseous refrigerant can be introduced into the economizer body 11; in the chiller, Figure 1 As shown, the feeding device for the gaseous refrigerant can be a condenser 3 or a two-stage compressor 2; when the feeding device for the gaseous refrigerant is the condenser 3, a gaseous refrigerant outlet is provided on the condenser 3, and the gaseous refrigerant in the condenser 3 can be discharged through the gaseous refrigerant outlet; the economizer air inlet 16 is connected with the gaseous refrigerant outlet of the condenser 3, so that the gaseous refrigerant in the condenser 3 can flow into the economizer body 11 through the pipeline connecting the economizer air inlet 16 and the gaseous refrigerant outlet of the condenser 3, and then through the economizer air inlet 16; when the feeding device for the gaseous refrigerant is the two-stage compressor 2, the economizer air inlet 16 can be connected with the exhaust port of the two-stage compressor 2, so that the gaseous refrigerant discharged from the two-stage compressor 2 can flow into the economizer body 11 through the pipeline connecting the economizer air inlet 16 and the exhaust port of the two-stage compressor 2, and then through the economizer air inlet 16, and mix with the liquid refrigerant in the economizer body 11.

[0047] The gaseous refrigerant and liquid refrigerant in the economizer body 11 will eventually separate into gas and liquid phases, forming a liquid refrigerant with a certain liquid level below the economizer body 11 and a gaseous refrigerant filling the gas phase space above the liquid refrigerant; the economizer exhaust port 17 provided on the economizer body 11 is connected to the gas phase space in the economizer body 11, so that the gaseous refrigerant in the economizer body 11 can be discharged from the economizer body 11 through the economizer exhaust port 17. Figure 1 As shown, in the chiller, the two-stage compressor 2 is provided with an air supply port, and the economizer exhaust port 17 can be connected to the air supply port of the two-stage compressor 2, so that the gaseous refrigerant in the economizer body 11 can flow into the two-stage compressor 2 through the economizer exhaust port 17 and the air supply port, so as to be used to supply air to the secondary impeller of the two-stage compressor 2.

[0048] In the embodiment, by providing an independent economizer air inlet 16 and an economizer liquid inlet 15 on the economizer body 11, the feed of gaseous refrigerant and the feed of liquid refrigerant into the economizer body 11 do not interfere with each other. The gaseous refrigerant can enter the economizer body 11 through an independent conveying pipeline via the economizer air inlet 16, and the liquid refrigerant can also enter the economizer body 11 through another independent conveying pipeline via the economizer liquid inlet 15. Therefore, the feed amount of liquid refrigerant and the feed amount of gaseous refrigerant into the economizer body 11 can be independently controlled, so that the liquid refrigerant and the gaseous refrigerant are mixed in the economizer body 11 in different proportions, thereby changing the internal pressure of the economizer body 11 to obtain different exhaust pressures of the economizer body 11, thereby achieving regulation of the exhaust pressure of the economizer body 11. At the same time, the exhaust volume of the gaseous refrigerant in the economizer body 11 can be regulated and controlled by controlling the opening of the economizer exhaust port 17, so that the flash economizer 1 of the present application can adjust both the exhaust pressure and the exhaust volume.

[0049] When it is necessary to increase the exhaust pressure of the gaseous refrigerant in the economizer body 11, the feed flow rate of the gaseous refrigerant can be increased alone or the feed flow rate of the liquid refrigerant can be reduced alone. Alternatively, the feed flows of the gaseous refrigerant and the liquid refrigerant can be adjusted simultaneously, that is, the feed flow rate of the gaseous refrigerant can be increased while the feed flow rate of the liquid refrigerant can be reduced. Moreover, by adjusting the feed flow rates of the gaseous refrigerant and the liquid refrigerant simultaneously, the pressure inside the economizer body 11 and the exhaust pressure can reach the predetermined exhaust pressure value more quickly and stably compared to adjusting the feed flow rates of the gaseous refrigerant or the liquid refrigerant alone.

[0050] Likewise, when the exhaust pressure of the gaseous refrigerant in the economizer body 11 is required, the feed flow rate of the gaseous refrigerant may be reduced or the feed flow rate of the liquid refrigerant may be increased, or the feed flow rate of the gaseous refrigerant may be increased while reducing the feed flow rate of the liquid refrigerant.

[0051] In one embodiment of the present application, preferably, Figure 1 and Figure 2 As shown, the flash economizer 1 further includes a liquid inlet flow regulating valve 112, which is arranged at the economizer liquid inlet 15, and the outlet of the liquid inlet flow regulating valve 112 is connected to the economizer liquid inlet 15, and the inlet of the liquid inlet flow regulating valve 112 is connected to the liquid refrigerant outlet of the condenser 3. The liquid refrigerant in the condenser 3 needs to flow into the economizer body 11 through the liquid inlet flow regulating valve 112; therefore, the feed flow rate of the liquid refrigerant of the economizer body 11 can be controlled by controlling the opening of the liquid inlet flow regulating valve 112.

[0052] In one embodiment of the present application, preferably, Figure 1 As shown, a throttling orifice plate 114 may also be provided at the liquid inlet 15 of the economizer, and be connected to the liquid refrigerant outlet of the condenser 3 through the throttling orifice plate 114, so as to regulate the flow of the liquid refrigerant flowing from the condenser 3 into the economizer body 11 through the throttling orifice plate 114.

[0053] In one embodiment of the present application, preferably, Figure 1 As shown, a liquid inlet flow regulating valve 112 and a throttling orifice 114 can be simultaneously installed at the economizer liquid inlet 15. These valves are installed in parallel on the pipeline between the economizer liquid inlet 15 and the liquid refrigerant outlet of the condenser 3. The regulating valves have an optimal flow regulation range based on their performance. For example, when the opening of the liquid inlet flow regulating valve 112 is between 10% and 90%, the liquid inlet flow can be precisely controlled. However, when the opening is less than 10%, a certain deviation may occur, resulting in inaccurate liquid inlet flow control. The throttling orifice 114, on the other hand, can effectively control the feed of small liquid flows. Therefore, the liquid inlet flow regulating valve 112 and the throttling orifice 114 jointly control the liquid refrigerant feed flow rate into the economizer body 11, thereby improving the control accuracy of the liquid refrigerant feed flow rate. This ensures the feed accuracy of both large and small liquid refrigerant flows.

[0054] In one embodiment of the present application, preferably, Figure 1 and Figure 2 As shown, the flash economizer 1 further includes an air intake flow regulating valve 111, which is arranged at the economizer air inlet 16, and the outlet of the air intake flow regulating valve 111 is connected to the economizer air inlet 16, and the inlet of the air intake flow regulating valve 111 is connected to the gaseous refrigerant outlet on the condenser 3 or the exhaust port of the two-stage compressor 2, so that the gaseous refrigerant from the condenser 3 or the two-stage compressor 2 can flow into the economizer body 11 through the air intake flow regulating valve 111, and by adjusting the opening of the air intake flow regulating valve 111, the flow of the gaseous refrigerant entering the economizer body 11 can be controlled and adjusted.

[0055] In one embodiment of the present application, preferably, the flash economizer 1 further includes a pressure detection device, which is provided at the economizer exhaust port 17 to detect the exhaust pressure of the economizer body 11 through the pressure detection device, and the pressure detection device is communicatively connected with an air intake flow control valve 111 provided at the economizer air inlet 16 and a liquid intake flow control valve 112 provided at the economizer liquid inlet 15; thereby, the openings of the air intake flow control valve 111 and the liquid intake flow control valve 112 can be adjusted according to the exhaust pressure of the economizer body 11 measured by the pressure detection device, so as to realize the control and adjustment of the feed flow of the gaseous refrigerant and the liquid refrigerant of the economizer body 11, so that the gaseous refrigerant and the liquid refrigerant can be mixed in the economizer body 11 and the required exhaust pressure of the economizer body 11 can be obtained.

[0056] Preferably, the pressure detection device is a pressure sensor.

[0057] In the chiller, the chiller is equipped with a control system. The pressure detection equipment, the air intake flow regulating valve 111 and the liquid intake flow regulating valve 112 of the flash economizer 1 are all communicatively connected to the control system of the chiller. The pressure detection equipment can detect the exhaust pressure of the economizer body 11 in real time, and upload the measured exhaust pressure of the economizer body 11 to the control system of the chiller; at the same time, the control system of the chiller can also control and adjust the opening of the air intake flow regulating valve 111 and the liquid intake flow regulating valve 112, so that the exhaust pressure of the economizer body 11 can be adjusted to the required pressure by adjusting the feed amount of gaseous refrigerant and liquid refrigerant of the economizer body 11.

[0058] During the operation of the chiller, as the load and operating conditions change, the operating conditions of the two-stage compressor 2 will deviate from the design conditions, causing a pressure imbalance between the first-stage impeller and the second-stage impeller of the two-stage compressor 2, causing the chiller to deviate from the optimal operating point, resulting in a decrease in the energy efficiency of the chiller. At this time, it is necessary to adjust the air supply pressure of the economizer body 11 to the two-stage compressor 2 to correct the pressure imbalance problem.

[0059] When the control system of the chiller determines that the two-stage compressor 2 is in a pressure imbalance state based on the data measured by the detection equipment for monitoring the operating status of the two-stage compressor 2, such as that provided on the two-stage compressor 2, the control system will automatically switch to the energy efficiency optimization control mode. The control system can calculate the required air supply pressure of the two-stage compressor 2, that is, the exhaust pressure of the economizer body 11, based on the built-in energy efficiency optimization algorithm of the two-stage compressor 2; then the control system will control the opening of the air inlet flow regulating valve 111 and the liquid inlet flow regulating valve 112 on the economizer body 11 to The flow rates of the gaseous refrigerant and the liquid refrigerant entering the economizer body 11 are adjusted so that the gaseous refrigerant and the liquid refrigerant are mixed in the economizer body 11 to adjust the pressure in the economizer body 11, thereby adjusting the exhaust pressure of the economizer body 11, until the pressure detection equipment provided at the economizer exhaust port 17 measures that the exhaust pressure of the economizer body 11 reaches the required gas supply pressure; thereby correcting the pressure imbalance problem, allowing the first-stage impeller and the second-stage impeller of the two-stage compressor 2 to return to the optimal operating condition, and thus improving the operating energy efficiency of the chiller through this control mode.

[0060] In one embodiment of the present application, preferably, Figure 1 and Figure 2 As shown, the flash economizer 1 also includes an exhaust flow regulating valve 113, which is arranged at the economizer exhaust port 17. The inlet of the exhaust flow regulating valve 113 is connected to the economizer exhaust port 17, and the outlet of the exhaust flow regulating valve 113 is connected to the air supply port of the two-stage compressor 2; the gaseous refrigerant in the economizer body 11 can be discharged to the two-stage compressor 2 through the exhaust flow regulating valve 113 to supply air to the two-stage compressor 2, and by adjusting the opening of the exhaust flow regulating valve 113, the exhaust volume of the gaseous refrigerant in the economizer body 11 can be controlled and adjusted.

[0061] Preferably, the exhaust flow regulating valve 113 is communicatively connected to a pressure detection device provided at the economizer exhaust port 17, so that the opening of the exhaust flow regulating valve 113 can be adjusted according to the exhaust pressure of the economizer body 11 measured by the pressure detection device to adjust the exhaust flow of the economizer body 11.

[0062] In a chiller, the two-stage compressor 2 may surge when operating under certain operating conditions such as guide vane adjustment, and surge generally occurs under conditions of small flow and high pressure ratio; therefore, when the two-stage compressor 2 surges, it is necessary to properly deliver high-pressure gaseous refrigerant to the secondary impeller of the two-stage compressor 2 and increase the flow rate of the delivered gaseous refrigerant to reduce the operating pressure ratio of the two-stage compressor 2, thereby alleviating the surge phenomenon of the two-stage compressor 2.

[0063] During the operation of the chiller, when the control system of the chiller determines that the two-stage compressor 2 is at the surge boundary based on the data measured by the detection equipment for monitoring the operating status of the two-stage compressor 2, such as that installed on the two-stage compressor 2, the control system of the chiller will automatically switch the control mode to the regulatory control mode, and the control system will calculate the air supply pressure of the two-stage compressor 2 at this time, that is, the exhaust pressure of the economizer body 11, through the built-in algorithm; then the control system will adjust the feed amount of gaseous refrigerant and liquid refrigerant entering the economizer body 11 by controlling the opening of the liquid inlet flow regulating valve 112 and the air inlet flow regulating valve 111 of the flash economizer 1, thereby realizing the adjustment of the exhaust pressure of the economizer body 11, until the exhaust pressure measured by the pressure detection equipment installed at the economizer exhaust port 17 reaches the air supply pressure required by the two-stage compressor 2 calculated by the control system.

[0064] At the same time, the chiller's control system also calculates the required air flow rate for two-stage compressor 2, i.e., the exhaust volume of economizer body 11, based on the return pressure between the primary and secondary impellers of two-stage compressor 2 and the discharge pressure of the gaseous refrigerant in economizer body 11. The exhaust flow control valve 113 of flash economizer 1 is also communicatively connected to the chiller's control system, enabling the control system to adjust the opening of the exhaust flow control valve 113 to regulate the exhaust volume of economizer body 11 until the exhaust volume of economizer body 11 reaches the required air flow rate for two-stage compressor 2 as calculated by the control system.

[0065] Therefore, the flash economizer 1 of the present application can simultaneously adjust the exhaust volume and exhaust pressure of the economizer body 11. When surge occurs in the two-stage compressor 2, the exhaust pressure and exhaust volume of the economizer body 11 can be adjusted at the same time, the exhaust pressure can be increased and the exhaust volume can be increased to reduce the working pressure ratio of the secondary impeller of the two-stage compressor 2, thereby effectively alleviating the surge phenomenon of the two-stage compressor 2.

[0066] At the same time, since the flash economizer 1 of the present application can independently control the feed amounts of liquid refrigerant and gaseous refrigerant to achieve regulation of the exhaust pressure of the flash economizer 1, and can also regulate the exhaust flow of the flash economizer 1; therefore, in the regulation process of alleviating the surge phenomenon of the two-stage compressor 2, the control system of the chiller can calculate the increase amplitude and increase rate of the exhaust pressure of the flash economizer 1 based on the working pressure ratio of the secondary impeller of the two-stage compressor 2 after real-time adjustment and the real-time exhaust volume, thereby further improving the efficiency to alleviate the surge phenomenon of the two-stage compressor 2.

[0067] Furthermore, since a separate economizer air inlet 16 is provided on the economizer body 11 to convey gaseous refrigerant into the economizer body 11, the economizer body 11 can provide a larger air supply volume for the two-stage compressor 2 by increasing the air supply volume of the gaseous refrigerant into the economizer body 11. This not only expands the surge limit of the two-stage compressor 2, but also reduces the flow rate of the gaseous refrigerant flowing through the condenser 3 due to the large amount of gaseous refrigerant flowing into the economizer body 11, thereby further reducing the minimum cooling capacity of the chiller and improving the adjustability of all working conditions.

[0068] In one embodiment of the present application, preferably, Figure 2 As shown, a partition 12 is provided in the economizer body 11. The partition 12 is provided in the middle of the economizer body 11 to divide the internal space of the economizer body 11 into two chambers through the partition 12, namely, a first chamber located below the economizer body 11 and a second chamber located above the economizer body 11; an economizer liquid inlet 15 is provided on the bottom wall of the economizer body 11 and communicates with the first chamber, so that liquid refrigerant can enter the first chamber of the economizer body 11 through the economizer liquid inlet 15 and form a certain liquid level height in the first chamber.

[0069] The economizer air inlet 16 is also connected to the first chamber and is located below the liquid level of the liquid refrigerant in the first chamber so that gaseous refrigerant can be charged into the liquid refrigerant in the economizer body 11 to fully mix the gaseous refrigerant with the liquid refrigerant. Then, the liquid refrigerant and gaseous refrigerant with different feed flow rates quickly build up pressure in the economizer body 11, so that the pressure in the economizer body 11, i.e., the exhaust pressure of the economizer body 11, quickly reaches the gas replenishment pressure required by the two-stage compressor 2.

[0070] Preferably, if Figure 2 As shown, a vent 13 is formed on the partition 12, and the first chamber and the second chamber are connected through the vent 13, so that the gaseous refrigerant flashed out of the first chamber can flow through the vent 13 into the second chamber located above the economizer body 11. An economizer exhaust port 17 is provided on the top wall of the economizer body 11 and is connected to the second chamber, so that the gaseous refrigerant at a predetermined pressure in the economizer body 11 can be discharged from the economizer body 11 through the economizer exhaust port 17 to replenish the two-stage compressor 2.

[0071] In this embodiment, preferably, Figure 2As shown, a filter screen 14 is provided at the air vent 13, through which the gaseous refrigerant flowing from the first chamber into the second chamber can be filtered, and the liquid refrigerant carried in the gaseous refrigerant can be filtered out, thereby preventing the gaseous refrigerant from carrying the liquid refrigerant into the two-stage compressor 2 and affecting the normal operation of the two-stage compressor 2.

[0072] Preferably, the partition 12 is plate-shaped and is placed transversely in the middle of the economizer body 11 to separate the economizer body 11 into two upper and lower chambers.

[0073] Preferably, the filter 14 can be laid on the upper or lower surface of the partition 12 to cover the vent 13, so that the filter 14 can filter the gaseous refrigerant flowing from the first chamber into the second chamber and almost filter out the liquid refrigerant carried in the gaseous refrigerant.

[0074] Preferably, the filter 14 can also be adapted to the vent 13 so that the filter 14 can be exactly assembled in the vent 13 to filter the gaseous refrigerant.

[0075] Preferably, the partition can also be a filter screen, which is placed horizontally in the middle of the economizer body 11. The gaseous refrigerant and the liquid refrigerant enter the first chamber below the filter screen through the economizer air inlet 16 and the economizer liquid inlet 15 respectively, and are fully mixed in the first chamber; the flashed gaseous refrigerant enters the second chamber above the filter screen through the filter screen, and the liquid refrigerant carried in the gaseous refrigerant is filtered out by the filter screen. Finally, the gaseous refrigerant in the second chamber is discharged through the economizer exhaust port 17 connected to the second chamber to replenish air to the two-stage compressor 2.

[0076] In one embodiment of the present application, preferably, Figure 2 As shown, a disperser 110 is further provided in the economizer body 11. The disperser 110 is connected to the economizer air inlet 16 through a connecting pipe, and a plurality of gas dispersion ports are provided on the disperser 110, so that the gaseous refrigerant entering through the economizer air inlet 16 can be sprayed into the liquid refrigerant in the economizer body 11 in a jet shape through the plurality of gas dispersion ports of the disperser 110, thereby making the gaseous refrigerant and the liquid refrigerant more fully mixed, so that the pressure in the economizer body 11 can be quickly built up.

[0077] Preferably, the disperser 110 is a nozzle, which is connected to the liquid inlet 15 of the economizer through a connecting pipe to spray the gaseous refrigerant into the liquid refrigerant.

[0078] Preferably, the disperser 110 can also be an annular pipe, which is connected to the economizer air inlet 16 through a connecting pipe. The annular pipe is provided with a plurality of gas dispersion ports with a diameter of 0.5-1 mm at intervals so that the gaseous refrigerant can be sprayed into the liquid refrigerant.

[0079] In one embodiment of the present application, preferably, Figure 2 As shown, a mixing chamber 19 is further provided in the economizer body 11. The mixing chamber 19 is located in the first chamber and communicates with the first chamber, and the mixing chamber 19 has a relatively small volume. The economizer liquid inlet 15 and the economizer air inlet 16 are both communicated with the mixing chamber 19, so that the liquid refrigerant and the gaseous refrigerant entering the economizer body 11 can first enter the mixing chamber 19 with a relatively small volume and mix in the mixing chamber 19, so that the gaseous refrigerant and the liquid refrigerant can be more fully mixed. The fully mixed liquid refrigerant and the gaseous refrigerant then pass through the mixing chamber 19 into the first chamber for flash evaporation.

[0080] Preferably, if Figure 2 As shown, the mixing chamber 19 is cylindrical, with its lower end welded to the bottom wall of the economizer body 11 and its upper end open, allowing the mixing chamber 19 to communicate with the first chamber. Simultaneously, the economizer liquid inlet 15, located on the bottom wall of the economizer body 11, is located within the mixing chamber 19, allowing liquid refrigerant to first enter the mixing chamber 19 and then flow into the first chamber via the mixing chamber 19. The economizer gas inlet 16 extends into the mixing chamber 19 through a connecting pipe, allowing gaseous refrigerant to first enter the mixing chamber 19 and fully mix with the liquid refrigerant.

[0081] Preferably, the disperser 110 is installed at one end of the connecting pipe located in the mixing chamber 19 .

[0082] In this embodiment, preferably, an economizer drain port 18 is further provided on the bottom wall of the economizer body 11, the economizer drain port 18 is communicated with the first chamber, and the economizer inlet 15 and the economizer drain port 18 are relatively spaced apart and arranged on both sides of the length direction of the economizer body 11; preferably, a partition is further provided on the bottom wall of the economizer body 11, the partition is vertically arranged between the economizer inlet 15 and the economizer drain port 18, and the partition is located on the side close to the economizer drain port 18, so that a certain liquid level height can be formed in the space of the first chamber on the side of the partition facing the economizer inlet 15, and the liquid refrigerant can flash evaporate in the first chamber; then the liquid refrigerant can overflow over the partition into the first chamber on the side of the partition facing the economizer drain port 18, and be discharged through the economizer drain port 18.

[0083] In the chiller, the economizer drain port 18 is used to communicate with the evaporator 4 of the chiller. The liquid refrigerant in the economizer body 11 can be discharged into the evaporator 4 through the economizer drain port 18. After evaporation in the evaporator 4, it becomes gaseous refrigerant and is transported back to the air inlet of the two-stage compressor 2 to supply air to the two-stage compressor 2.

[0084] The present application also provides a chiller unit, such as Figure 1 As shown, it includes a flash economizer 1 according to any one of the above embodiments.

[0085] In this embodiment, the chiller includes the flash economizer 1 , so the chiller has all the beneficial effects of the flash economizer 1 , which will not be described in detail here.

[0086] The chiller also includes a two-stage centrifugal compressor (two-stage compressor 2), a condenser 3, and an evaporator 4. The two-stage compressor 2 includes an air inlet, an exhaust port, and an air supply port. The exhaust port of the two-stage compressor 2 is connected to the condenser 3 to discharge the gaseous refrigerant into the condenser 3 for condensation. The condenser 3 is a shell and tube heat exchanger, and the medium in the tube is the refrigerant. The upper part of the shell of the condenser 3 is provided with an inlet and a gaseous refrigerant outlet, and the lower part of the shell of the condenser 3 is provided with a liquid refrigerant outlet. The condenser 3 is connected to the exhaust port of the two-stage compressor 2 through the inlet, allowing the gaseous refrigerant to enter the condenser 3 so that the gaseous refrigerant can be condensed in the condenser 3. The liquid refrigerant outlet of the condenser 3 is connected to the economizer liquid inlet 15, so that the liquid refrigerant condensed in the condenser 3 can be discharged into the flash economizer 1 (referred to as the economizer); the gaseous refrigerant outlet of the condenser 3 is connected to the economizer air inlet 16, so that the gaseous refrigerant in the space above the shell of the condenser 3 can be discharged into the economizer.

[0087] The economizer exhaust port 17 is connected to the air supply port of the two-stage compressor 2. The gaseous refrigerant and the liquid refrigerant can enter the economizer body 11 at predetermined flow rates to be fully mixed and flash evaporated, so that the economizer body 11 can supply the gaseous refrigerant to the two-stage compressor 2 at a certain pressure and flow rate to alleviate the pressure imbalance or surge of the two-stage compressor 2.

[0088] The evaporator 4 is provided with an inlet and an exhaust port. The inlet of the evaporator 4 is connected to the economizer discharge port 18, and the exhaust port of the evaporator 4 is connected to the air inlet of the two-stage compressor 2. The economizer can discharge the liquid refrigerant inside into the evaporator 4, causing the liquid refrigerant to evaporate into a gaseous state within the evaporator 4. The evaporated gaseous refrigerant is then discharged into the air inlet of the two-stage compressor 2 to supply air to the two-stage compressor 2, which compresses the gaseous refrigerant to perform work. This allows the refrigerant to flow between the two-stage compressor 2, the condenser 3, the economizer, and the evaporator 4, ensuring efficient operation of the chiller.

[0089] In this embodiment, preferably, the air supply port of the two-stage compressor 2 is provided on the return channel 21 between the primary impeller and the secondary impeller of the two-stage compressor 2. The return channel 21 can be an external return pipe, that is, one end of the return pipe is connected to the exhaust of the primary impeller, and the other end of the return pipe is connected to the intake of the secondary impeller. The middle part of the return pipe is provided with an air supply port for connection to the economizer. The return channel 21 can also be without a distinct return pipe, that is, the return channel 21 for connecting the primary impeller and the secondary impeller is formed integrally in the housing of the two-stage compressor 2. The housing of the two-stage compressor 2 is provided with an interface connected to the return channel 21 for connecting to the economizer exhaust port 17, thereby enabling the economizer to supply air to the two-stage compressor 2.

[0090] The present application also provides an air-conditioning system, comprising the chiller of the above embodiment.

[0091] In this embodiment, the air conditioning system includes a chiller, so the air conditioning system has all the beneficial effects of the chiller, which will not be described in detail here.

[0092] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A chiller, characterized in that: Includes flash economizer, two-stage centrifugal compressor, condenser and evaporator; The flash economizer includes an economizer body, which is provided with: an economizer liquid inlet, for introducing liquid refrigerant into the economizer body; an economizer air inlet, for introducing gaseous refrigerant into the economizer body; an economizer exhaust port for discharging the liquid refrigerant and the gaseous refrigerant flashed out of the economizer body; A pressure detection device is provided at the exhaust port of the economizer; The economizer air inlet is provided with an air intake flow regulating valve, and the air intake flow regulating valve is communicatively connected to the pressure detection device; The liquid inlet of the economizer is provided with a liquid inlet flow regulating valve, and the liquid inlet flow regulating valve is communicatively connected with the pressure detection device; The liquid inlet of the economizer is also provided with a throttling orifice plate, and the throttling orifice plate is connected in parallel with the liquid inlet flow regulating valve; The exhaust port of the two-stage centrifugal compressor is connected to the refrigerant inlet of the condenser; The gaseous refrigerant outlet of the condenser is connected to the air inlet of the economizer, and the liquid refrigerant outlet of the condenser is connected to the liquid inlet of the economizer; The economizer exhaust port is connected to the air supply port of the two-stage centrifugal compressor, and the economizer liquid discharge port formed by the flash economizer is connected to the inlet of the evaporator; The exhaust port of the evaporator is communicated with the air inlet of the two-stage centrifugal compressor.

2. The chiller according to claim 1, characterized in that: The economizer exhaust port is provided with an exhaust flow regulating valve, and the exhaust flow regulating valve is communicatively connected with the pressure detection device.

3. The chiller according to claim 1, characterized in that: A disperser is provided in the economizer body; The disperser is communicated with the air inlet of the economizer, and a plurality of gas dispersion ports are provided on the disperser.

4. The chiller according to claim 3, characterized in that: The disperser is a nozzle.

5. The chiller according to any one of claims 1 to 4, characterized in that: A mixing chamber in communication with the economizer body is provided in the economizer body, and the economizer air inlet and the economizer liquid inlet are located in the mixing chamber.

6. The chiller according to claim 1, characterized in that: A partition is provided in the economizer body, and the partition divides the economizer body into a first chamber located at the bottom and a second chamber located at the top; The economizer liquid inlet and the economizer air inlet are in communication with the first chamber, and the economizer body is further provided with an economizer liquid discharge port in communication with the first chamber for discharging liquid refrigerant in the first chamber; The partition is provided with a vent, through which the gaseous refrigerant flashed out of the first chamber can enter the second chamber, and the vent is provided with a filter for filtering the gaseous refrigerant; The economizer exhaust port is communicated with the second chamber.

7. An air conditioning system, characterized in that: A chiller comprising the chiller according to any one of claims 1 to 6.

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