Parallel compressor unit

Abstract

The utility model provides a parallel compressor unit which comprises a plurality of compressors arranged in parallel, an oil separator, a liquid storage device and an air suction header pipe, the liquid storage device is communicated with a liquid inlet of a tail end / barrel pump and / or the air suction header pipe through a liquid supply pipe, an air return header pipe of the tail end / barrel pump is communicated with the air suction header pipe, and the air suction header pipe comprises a heat exchange pipe and a circular pipe with two closed ends. The heat exchange pipe is arranged in the circular pipe, two open ends of the heat exchange pipe penetrate through one end plate of the circular pipe from inside to outside, one open end of the heat exchange pipe is communicated with an oil outlet of the oil separator and / or the liquid supply pipe, the other open end of the heat exchange pipe is communicated with the oil return pipe and / or the liquid supply supercooling pipe on the tail end / barrel pump, and the oil return pipe is communicated with oil inlets of the compressors. And a gas outlet of the suction header is communicated with refrigerant inlets of the plurality of compressors. The parallel compressor unit is simple in structure, capable of improving the superheat degree and the supercooling degree of air suction, capable of protecting the compressors from the risk of liquid impact, capable of prolonging the service life of the compressors and low in unit cost.

Description

Technical Field

[0001] The utility model belongs to the technical field of refrigeration systems, and particularly relates to a parallel compressor unit. Background Art

[0002] During the refrigeration process of refrigeration equipment, its compressor will discharge a mixture of high-temperature and high-pressure superheated refrigerant and lubricating oil. The existing oil cooling method for refrigeration equipment is to use the condensed liquid in the evaporative condenser to cool the lubricating oil through an oil-cooling plate heat exchanger to keep the oil temperature within the normal working range. However, when using this oil cooling method, a siphon tank must be set before the oil-cooling plate heat exchanger to avoid the situation that the lubricating oil cannot be cooled due to liquid breakage; moreover, when the existing refrigeration equipment is at low load at the end, the unit is prone to frequent start-stop and liquid return. The main method to solve this situation is to add a gas-liquid separator at the end of the return gas, so that the unevaporated refrigerant at the end remains in the gas-liquid separator to prevent liquid return to the compressor. That is to say, in the existing refrigeration equipment, the cooling treatment of the high-temperature lubricating oil in the mixture of high-temperature and high-pressure superheated refrigerant and lubricating oil discharged by the compressor and the treatment of the low-temperature and low-pressure refrigerant gas-liquid mixture in the end return gas are carried out separately by two devices, which results in the complex structure of the existing refrigeration equipment and high unit cost.

[0003] On the other hand, the existing liquid supply method for the operation of the compressor unit of refrigeration equipment is to store the condensed liquid in the evaporative condenser in a liquid storage tank. The refrigerant liquid coming out of the liquid storage tank directly enters the end evaporation heat exchange through the liquid supply pipe. The lower the temperature of the refrigerant liquid entering the end evaporator, the higher the subcooling degree of the compressor unit and the better the refrigeration effect. If a refrigerant cooling structure is set separately, it will inevitably further increase the unit cost. Content of the Utility Model

[0004] In view of the above problems, the utility model provides a parallel compressor unit.

[0005] To achieve the above purpose, the utility model adopts the following technical scheme:

[0006] A parallel compressor unit includes a plurality of compressors, an oil separator, a liquid storage tank, and a suction header arranged in parallel. The exhaust pipes of the plurality of compressors are all connected to the inlet of the oil separator through an exhaust header. The gas outlet of the oil separator is connected to the inlet of the evaporative condenser through an exhaust pipe. The liquid storage tank is connected to the liquid outlet of the evaporative condenser through a liquid dropping pipe. The liquid storage tank is connected to the inlet of the end / barrel pump through a liquid supply pipe. The return gas main pipe of the end / barrel pump is connected to the suction header. The suction header includes a heat exchange pipe and a circular pipe with both ends closed. The heat exchange pipe is arranged inside the circular pipe. The two open ends of the heat exchange pipe penetrate through one end plate of the circular pipe from the inside to the outside. One open end of the heat exchange pipe is connected to the oil outlet of the oil separator, and the other open end is connected to an oil return pipe. The oil return pipe is connected to the oil inlets of the plurality of compressors.

[0007] It is understandable that by setting the suction header, heat exchange is achieved between the high-temperature lubricating oil and the low-temperature and low-pressure refrigeration gas-liquid mixture, so that a single suction header can not only cool the lubricating oil, but also solve the technical problems of frequent start-stop of the unit and liquid return in the case of low load at the end of the refrigeration equipment. Compared with the prior art, this setting makes the structure of the refrigeration equipment simple and reduces the unit cost.

[0008] Furthermore, the heat exchange tube is a first U-shaped elbow. The two open ends of the first U-shaped elbow are respectively connected to the oil outlet of the oil separator and the oil return pipe. An air-liquid inlet pipe and a plurality of air outlet pipes are arranged on the outer side wall of the circular pipe. The air-liquid inlet pipe and the plurality of air outlet pipes are respectively connected to the circular pipe. The return air main pipe of the end / pump barrel is connected to the air-liquid inlet pipe. The number of the air outlet pipes is the same as the number of compressors. The plurality of air outlet pipes are arranged at intervals, and the plurality of air outlet pipes are connected to the air inlet of the plurality of compressors in one-to-one correspondence.

[0009] It is understandable that the setting of the first U-shaped elbow realizes the heat exchange between the high-temperature lubricating oil and the low-temperature and low-pressure refrigerant gas-liquid mixture. The structural form of the first U-shaped elbow increases the residence time of the high-temperature lubricating oil in the suction header and increases the heat exchange area, making the heat exchange more sufficient.

[0010] A parallel compressor unit includes a plurality of compressors, an oil separator, a liquid receiver and a suction header which are arranged in parallel. The exhaust pipes of the plurality of compressors are all connected to the inlet of the oil separator through an exhaust header. The air outlet of the oil separator is connected to the air inlet of the evaporative condenser through an exhaust pipe. The liquid receiver is connected to the liquid outlet of the evaporative condenser through a liquid dropping pipe. The return air main pipe of the end / pump barrel is connected to the suction header. The suction header includes a heat exchange tube and a circular tube with both ends closed. The heat exchange tube is arranged inside the circular tube. The two open ends of the heat exchange tube penetrate through one end plate of the circular tube from the inside to the outside. The liquid receiver is connected to one open end of the heat exchange tube through a liquid supply pipe, and the other open end is connected to the liquid supply sub-cooling pipe on the liquid supply port of the end / pump barrel. The gas outlet of the suction header is connected to the refrigerant inlets of the plurality of compressors.

[0011] It is understandable that by setting the suction header, heat exchange is achieved between the refrigerant liquid from the liquid receiver and the low-temperature and low-pressure refrigerant gas-liquid mixture from the end / pump barrel, so that the temperature of the refrigerant liquid entering the end / pump barrel is lower and the system sub-cooling degree is increased.

[0012] Furthermore, the heat exchange tube is a second U-shaped elbow. The two open ends of the second U-shaped elbow are respectively connected to the liquid supply pipe and the liquid supply sub-cooling pipe. An air-liquid inlet pipe and a plurality of air outlet pipes are arranged on the outer side wall of the circular tube. The air-liquid inlet pipe and the plurality of air outlet pipes are respectively connected to the circular tube. The return air main pipe of the end / pump barrel unit is connected to the air-liquid inlet pipe. The number of the air outlet pipes is the same as the number of compressors. The plurality of air outlet pipes are arranged at intervals, and the plurality of air outlet pipes are connected to the air inlets of the plurality of compressors in one-to-one correspondence.

[0013] It can be understood that the setting of the second U-shaped elbow realizes the heat exchange between the refrigerant and the low-temperature and low-pressure refrigerant gas-liquid mixture. The structural form of the second U-shaped elbow increases the residence time of the refrigerant liquid in the suction header, and at the same time increases the heat exchange area, making the heat exchange more sufficient.

[0014] A parallel compressor unit includes a plurality of compressors, an oil separator, a liquid receiver, and a suction header arranged in parallel. The exhaust pipes of the plurality of compressors are all connected to the inlet of the oil separator through an exhaust header. The gas outlet of the oil separator is connected to the inlet of the evaporative condenser through an exhaust pipe. The liquid receiver is connected to the liquid outlet of the evaporative condenser through a downcomer. The return gas main pipe of the terminal / barrel pump is connected to the suction header. The suction header includes two heat exchange pipes and a circular pipe with both ends closed. The two heat exchange pipes are arranged inside the circular pipe. The two open ends of the two heat exchange pipes penetrate through one end plate of the circular pipe from the inside to the outside. One open end of one heat exchange pipe is connected to the oil outlet of the oil separator, and the other open end is connected to the oil return pipe. The oil return pipe is connected to the oil inlets of the plurality of compressors. The liquid receiver is connected to one open end of the other heat exchange pipe through a supply pipe, and the other open end is connected to the supply subcooling pipe on the supply port of the terminal / barrel pump. The gas outlet of the suction header is connected to the refrigerant inlets of the plurality of compressors.

[0015] It can be understood that by setting the suction header, the heat exchange between the refrigerant liquid from the liquid receiver and the low-temperature and low-pressure refrigerant gas-liquid mixture from the terminal / barrel pump, as well as the heat exchange between the high-temperature lubricating oil and the low-temperature and low-pressure refrigerant gas-liquid mixture, are simultaneously realized, making the temperature of the refrigerant liquid entering the terminal / barrel pump lower, increasing the system subcooling degree. At the same time, by using a single suction header, the cooling of the lubricating oil is realized, and the technical problems of frequent start-stop and liquid return of the unit easily occurring in the case of low load at the end of the refrigeration equipment are solved. Compared with the prior art, this setting makes the structure of the refrigeration equipment simple and the cost of the unit reduced.

[0016] Further, the two heat exchange pipes are respectively a first U-shaped elbow and a second U-shaped elbow. The two ports of the first U-shaped elbow are respectively connected to the oil outlet of the oil separator and the oil return pipe. The two ports of the second U-shaped elbow are respectively connected to the supply pipe and the supply subcooling pipe on the supply port of the terminal / barrel pump. An air-liquid inlet pipe and a plurality of outlet pipes are arranged on the outer side wall of the circular pipe. The air-liquid inlet pipe and the plurality of outlet pipes are respectively connected to the circular pipe. The return gas main pipe of the terminal / barrel pump is connected to the air-liquid inlet pipe. The number of outlet pipes is the same as the number of compressors. The plurality of outlet pipes are arranged at intervals, and the plurality of outlet pipes are connected to the inlets of the plurality of compressors in one-to-one correspondence.

[0017] With such a setting, the heat exchange process of the refrigerant liquid and the high-temperature lubricating oil - low-temperature and low-pressure refrigerant gas-liquid mixture can be carried out simultaneously. While increasing the subcooling degree of the system and realizing oil cooling, the temperature of the low-temperature and low-pressure refrigerant gas-liquid mixture after heat exchange is higher, and the liquid vaporizes more fully.

[0018] Further, between an open end of the first U-shaped elbow and the oil outlet of the oil separator, they are connected in sequence along the oil flow direction through an oil supply pipe and an inlet pipe; the other open end of the first U-shaped elbow is connected to the return pipe through an outlet pipe, and the end of the oil supply pipe far from the oil separator is connected to the port of the inlet pipe far from the suction header; the end of the outlet pipe far from the suction header is connected to one end port of the return pipe.

[0019] Further, between an open end of the U-shaped elbow and the oil outlet of the oil separator, they are connected in sequence along the oil flow direction through an oil supply pipe and an inlet pipe; the oil supply pipe is also connected to the first inlet of the oil mixing valve, the other open end of the first U-shaped elbow is connected to the second inlet of the oil mixing valve through an outlet pipe, and the outlet of the oil mixing valve is connected to the return pipe.

[0020] It can be understood that the oil mixing valve is a valve component with a built-in temperature sensing element and self-adjusting opening. The constant temperature control element inside the oil mixing valve automatically adjusts the valve opening at the two oil inlet ports according to the oil temperature in the oil supply pipe and the outlet pipe to control the temperature at its outlet to the set temperature, achieving precise control of the temperature of the lubricating oil after mixing.

[0021] Further, a temperature sensor is provided on the side of the return pipe close to the oil mixing valve, and a solenoid valve is provided on the oil supply pipe. The temperature sensor and the solenoid valve are connected to the unit PLC for control.

[0022] It can be understood that when the temperature of the lubricating oil coming out of the oil separator does not need to be cooled, by controlling the solenoid valve to close, the lubricating oil is directly introduced into the return pipe, ensuring that the temperature of the lubricating oil entering the compressor is closer to the required temperature.

[0023] Further, a balance pipe is also connected to the liquid receiver, and the end of the balance pipe far from the liquid receiver is connected to the inlet of the evaporation condenser exhaust main pipe.

[0024] It can be understood that setting the balance pipe can balance the pressure between the liquid receiver and the condensation evaporator, enabling the refrigerant liquid in the evaporation condenser to smoothly fall into the liquid receiver.

[0025] The parallel compressor unit of the present utility model has a simple suction header structure. It can not only be used to achieve oil cooling, increase the suction superheat degree, protect the compressor from the risk of liquid slugging, extend the compressor life, but also reduce the siphon tank, oil cooling plate heat exchanger and gas-liquid separator compared with the prior art, thus reducing the unit cost. It can also be used to cool the refrigerant liquid, increase the subcooling degree of the system, or simultaneously cool the oil and the refrigerant liquid, increase the superheat degree and subcooling degree of the system, and complete the oil cooling together. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a schematic structural diagram of the parallel compressor unit according to Embodiment 1 of the present utility model Figure 1 ;

[0027] Figure 2 is a schematic structural diagram of the parallel compressor unit according to Embodiment 1 of the present utility model Figure 2 ;

[0028] Figure 3 is a schematic structural diagram of the suction header according to Embodiment 1 of the present utility model;

[0029] Figure 4 is a schematic structural diagram of the parallel compressor unit according to Embodiment 2 of the present utility model;

[0030] Figure 5 is a schematic structural diagram of the suction header according to Embodiment 2 of the present utility model;

[0031] Figure 6 is a schematic structural diagram of the parallel compressor unit according to Embodiment 3 of the present utility model Figure 1 ;

[0032] Figure 7 is a schematic structural diagram of the parallel compressor unit according to Embodiment 3 of the present utility model Figure 2 ;

[0033] Figure 8 is a schematic structural diagram of the suction header according to Embodiment 3 of the present utility model.

[0034] Among them, 1 - exhaust header, 2 - exhaust pipe, 3 - oil supply pipe, 4 - inlet oil pipe, 5 - outlet oil pipe, 6 - return oil pipe, 7 - liquid dropping pipe, 8 - balance pipe, 9 - oil mixing valve, 10 - liquid supply pipe, 11 - suction header, 12 - compressor, 13 - oil separator, 14 - liquid storage tank, 15 - temperature sensor, 16 - solenoid valve, 17 - liquid supply subcooling pipe, 111 - first U-shaped bend pipe, 112 - circular pipe, 113 - gas-liquid inlet pipe, 114 - outlet gas pipe, 115 - second U-shaped bend pipe, 121 - compressor exhaust pipe. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0035] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and in no way constitutes a limitation on the present invention and its application or use. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention. Embodiment

[0036] As Figure 1 shown, a parallel compressor unit, characterized in that it includes a plurality of compressors 12, oil separators 13, liquid receivers 14 and suction headers 11 arranged in parallel. A plurality of compressor exhaust pipes 121 are all connected to the inlet of the oil separator 13 through an exhaust header 1. The gas outlet of the oil separator 13 is connected to the inlet of the evaporative condenser through a discharge pipe 2. The liquid receiver 14 is connected to the liquid discharge port of the evaporative condenser through a liquid dropping pipe 7. The liquid receiver 14 is connected to the inlet of the terminal / barrel pump through a supply pipe 10. The return air main pipe of the terminal / barrel pump is connected to the suction header 11. The suction header 11 includes a heat exchange pipe and a circular pipe 112 with both ends closed. The heat exchange pipe is arranged inside the circular pipe 112. The two open ends of the heat exchange pipe penetrate through one end plate of the circular pipe 112 from the inside to the outside. One open end of the heat exchange pipe is connected to the oil outlet of the oil separator 13, and the other open end is connected to the oil return pipe 6. The oil return pipe 6 is connected to the oil inlets of a plurality of compressors.

[0037] In this embodiment, the gaseous refrigerant separated in the oil separator 13 enters the evaporative condenser through the discharge pipe, is liquefied in the evaporative condenser and then enters the liquid receiver through the liquid dropping pipe. The liquid refrigerant inside the liquid receiver enters the terminal through the supply pipe. The low-temperature and low-pressure gas-liquid mixture of the refrigerant coming out of the terminal enters the suction header to exchange heat with the high-temperature lubricating oil separated by the oil separator.

[0038] This embodiment combines the cooling of the high-temperature lubricating oil and the gasification of the low-temperature and low-pressure refrigeration gas-liquid mixture at the terminal in the suction header for heat exchange, realizing that a single suction header can not only cool the lubricating oil, but also solve the technical problems that the unit is prone to frequent start-stop and liquid return in the case of low load at the terminal of the refrigeration equipment. Compared with the prior art, this setting makes the structure of the refrigeration equipment simple and the cost of the unit reduced.

[0039] In some embodiments, a balance pipe 8 is further connected to the liquid receiver 14. One end of the balance pipe 8 far from the liquid receiver 14 is connected to the inlet of the evaporative condenser exhaust main pipe. Setting the balance pipe 8 can balance the pressure between the liquid receiver 14 and the condensation evaporator, so that the refrigerant liquid in the evaporative condenser can smoothly fall into the liquid receiver 8.

[0040] Specifically, as Figure 3 shown, the heat exchange tube is the first U-shaped elbow 111. The two open ends of the first U-shaped elbow 111 are respectively connected to the oil outlet of the oil separator 13 and the oil return pipe 6. A gas-liquid inlet pipe 113 and a plurality of gas outlet pipes 14 are provided on the outer side wall of the circular pipe 112. The gas-liquid inlet pipe 113 and the plurality of gas outlet pipes 14 are respectively connected to the circular pipe 112. The return gas main pipe of the end / barrel pump is connected to the gas-liquid inlet pipe 113. The number of the gas outlet pipes 14 is the same as the number of the compressors 12. The plurality of gas outlet pipes 114 are arranged at intervals, and the plurality of gas outlet pipes 114 are in one-to-one correspondence with the air inlets of the plurality of compressors 12 and are connected.

[0041] It can be understood that the setting of the first U-shaped elbow 111 increases the residence time of the lubricating oil in the suction header 11, and at the same time increases the heat exchange area, realizing the full heat exchange between the high-temperature lubricating oil and the low-temperature and low-pressure refrigerant gas-liquid mixture.

[0042] The bent end of the first U-shaped elbow 111 is arranged at an interval from the end plate on the other side of the circular pipe 112. In this way, the bent end of the first U-shaped elbow 111 is set in an unfixed form, and there is an interval between its circumferential side and the circular pipe 112, which enables the first U-shaped elbow 111 to have sufficient expansion and contraction space during the heat exchange process.

[0043] In this embodiment, as Figure 1 shown, between one open end of the U-shaped elbow 111 and the oil outlet of the oil separator 13, they are sequentially connected through an oil supply pipe 3 and an inlet pipe 4 along the oil flow direction; the oil supply pipe 3 is also connected to the first inlet of the oil mixing valve 9. The other open end of the first U-shaped elbow 111 is connected to the second inlet of the oil mixing valve 9 through an oil outlet pipe 5, and the outlet of the oil mixing valve 9 is connected to the oil return pipe 6. The oil mixing valve 9 is a valve component with a self-sensing temperature element and self-adjusting opening. The constant temperature control element inside the oil mixing valve 9 automatically adjusts the valve openings at the two oil inlet ports according to the oil temperatures in the oil supply pipe 3 and the oil outlet pipe 5 to control the temperature at its oil outlet to the set temperature, realizing the precise control of the temperature of the mixed lubricating oil.

[0044] On this basis, a temperature sensor 15 is provided on the side of the oil return pipe 6 close to the oil mixing valve 9, and a solenoid valve 16 is provided on the oil supply pipe 3. The temperature sensor 15 and the solenoid valve 16 are connected to the unit PLC for control. With this setting, when the temperature sensor 15 detects that the temperature of the lubricating oil entering the oil return pipe 6 after cooling and adjustment by the oil mixing valve 9 is lower than the set temperature, it indicates that the temperature of the lubricating oil coming out of the oil separator 13 is relatively low. At this time, the solenoid valve 16 is closed, and the lubricating oil coming out of the oil separator 13 directly enters the oil return pipe 6, ensuring that the temperature of the lubricating oil entering the compressor is closer to the required temperature when the temperature of the lubricating oil coming out of the oil separator 13 is relatively low.

[0045] AsFigure 2 As shown, it is communicated in sequence along the oil flow direction between an open end of the first U-shaped elbow 111 and an oil outlet of the oil separator 13 through an oil supply pipe 3 and an oil inlet pipe 4; the other open end of the first U-shaped elbow 111 is communicated with a return oil pipe 6 through an oil outlet pipe, and one end of the oil supply pipe 3 away from the oil separator 13 is communicated with a port of one end of the oil inlet pipe 4 away from the suction header 11; one end of the oil outlet pipe away from the suction header 11 is communicated with a port of one end of the return oil pipe 6. Embodiment

[0046] As Figure 4 and Figure 5 As shown, it includes a plurality of compressors 12, oil separators 13, liquid receivers 14 and suction headers 11 arranged in parallel. A plurality of compressor exhaust pipes 121 are all communicated with an inlet of the oil separator 13 through an exhaust header 1. An air outlet of the oil separator 13 is communicated with an air inlet of an evaporative condenser through an exhaust pipe 2. The liquid receiver 14 is connected with a liquid dropping port of the evaporative condenser through a liquid dropping pipe 7. A return air main pipe of the terminal / barrel pump is communicated with the suction header 11. The suction header 11 includes a heat exchange pipe and a circular pipe 112 with both ends closed. The heat exchange pipe is arranged inside the circular pipe 112. Two open ends of the heat exchange pipe penetrate through an end plate of the circular pipe 112 from the inside to the outside. The liquid receiver 14 is communicated with an open end of the heat exchange pipe through a liquid supply pipe 10, and the other open end is communicated with a liquid supply subcooling pipe 17 on a liquid supply port of the terminal / barrel pump unit. A gas outlet of the suction header 11 is communicated with refrigerant inlets of a plurality of compressors.

[0047] It can be understood that by arranging the suction header, heat exchange is realized between the refrigerant liquid from the liquid receiver and the low-temperature and low-pressure refrigerant gas-liquid mixture from the terminal / barrel pump, so that the temperature of the refrigerant liquid entering the terminal / barrel pump is lower, and the system subcooling degree is increased.

[0048] In this embodiment, the heat exchange pipe is a second U-shaped elbow 115. The structure of the suction header 11 in this embodiment is completely the same as the structure of the suction header 11 in Embodiment 1 and its setting mode in the system. The difference is that two ports of the second U-shaped elbow 115 are respectively communicated with the liquid supply pipe 10 and the liquid supply subcooling pipe 17 on the liquid supply port of the terminal / barrel pump unit.

[0049] In this embodiment, a balance pipe 8 is also connected to the liquid receiver 14. One end of the balance pipe 8 away from the liquid receiver 14 is connected to an inlet of an evaporative condenser exhaust main pipe. In this way, the bent end of the second U-shaped elbow 113 is set in an unfixed form, and there is an interval between its circumferential side and the circular pipe 112, which enables the second U-shaped elbow 113 to have enough expansion space during the heat exchange process. Embodiment

[0050] As Figure 6As shown in the figure, a parallel compressor unit includes a plurality of compressors 12, an oil separator 13, a liquid receiver 14, and a suction header 11 that are arranged in parallel. The exhaust pipes 121 of the plurality of compressors are all connected to the inlet of the oil separator 13 through an exhaust header 1. The gas outlet of the oil separator 13 is connected to the inlet of the evaporative condenser through an exhaust pipe 2. The liquid receiver 14 is connected to the liquid inlet of the evaporative condenser through a liquid dropping pipe 7. The return gas main pipe of the terminal / barrel pump is connected to the suction header 11. The suction header 11 includes two heat exchange pipes and a circular pipe 112 with both ends closed. The two heat exchange pipes are arranged inside the circular pipe 112. The two open ends of the two heat exchange pipes penetrate through one end plate of the circular pipe 112 from the inside to the outside. One open end of one heat exchange pipe is connected to the oil outlet of the oil separator 13, and the other open end is connected to the oil return pipe 6. The oil return pipe 6 is connected to the oil inlets of the plurality of compressors. The liquid receiver 14 is connected to one open end of the other heat exchange pipe through a liquid supply pipe 10, and the other open end is connected to the liquid supply subcooling pipe 17 on the liquid supply port of the terminal / barrel pump unit. The gas outlet of the suction header 11 is connected to the refrigerant inlets of the plurality of compressors.

[0051] It can be understood that by arranging the suction header, heat exchange is simultaneously achieved between the refrigerant liquid from the liquid receiver and the low-temperature and low-pressure refrigerant gas-liquid mixture from the terminal / barrel pump, as well as between the high-temperature lubricating oil and the low-temperature and low-pressure refrigerant gas-liquid mixture, making the temperature of the refrigerant liquid entering the terminal / barrel pump lower, increasing the system subcooling degree. At the same time, by using a single suction header, the cooling of the lubricating oil is realized, and the technical problems of frequent start-stop and liquid return of the unit that are prone to occur in the case of low load at the end of the refrigeration equipment are solved. Compared with the prior art, this setting makes the structure of the refrigeration equipment simple and reduces the cost of the unit.

[0052] As Figure 8 As shown in the figure, different from the suction header 11 in Embodiment 1, the suction header 11 in this embodiment contains two identical U-shaped bent pipes, that is, not only the first U-shaped bent pipe 111 is provided, but also the second first U-shaped bent pipe 113 is provided. The connection method of the second U-shaped bent pipe 115 to the circular pipe 112 is the same as that of the first U-shaped bent pipe 111. The two open ends of the first U-shaped bent pipe 111 and the second U-shaped bent pipe 115 penetrate through two different end plates on the circular pipe 112. The two ports of the first U-shaped bent pipe 111 are respectively connected to the oil outlet of the oil separator 13 and the oil return pipe 6. The two ports of the second first U-shaped bent pipe 111 are respectively connected to the liquid supply pipe 10 and the liquid supply subcooling pipe 17 on the liquid supply port of the terminal / barrel pump unit. Of course, in other embodiments, the open ends of the first U-shaped bent pipe 111 and the second first U-shaped bent pipe 115 can also penetrate through the same end plate of the circular pipe.

[0053] With such a setting, the heat exchange process of the refrigerant liquid and the high-temperature lubricating oil - low-temperature and low-pressure refrigerant gas-liquid mixture can be carried out simultaneously. While increasing the subcooling degree of the system and achieving oil cooling, the temperature of the low-temperature and low-pressure refrigerant gas-liquid mixture after heat exchange is higher, and the liquid vaporizes more fully.

[0054] As Figure 6 and Figure 7 shown, in this embodiment, the connection pipeline setting between the suction header 11 and the oil separator 13 and the connection pipeline setting between the suction header 11 and the compressor 12 are the same as those in Embodiment 1.

[0055] In this embodiment, a balance pipe 8 is also connected to the liquid receiver 14, and one end of the balance pipe 8 away from the liquid receiver 14 is connected to the inlet of the evaporation cooler exhaust main pipe. In this way, the bent ends of the first U-shaped bend 111 and the second U-shaped pipe 115 are set in an unfixed form, and there are intervals between their circumferences and the circular pipe 112, which enables the first U-shaped bend 111 and the second U-shaped pipe 115 to have sufficient expansion space during the heat exchange process.

[0056] Those of ordinary skill in the art should understand that the above are only specific embodiments of the present invention and are not used to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A parallel compressor unit, characterized in that: The invention comprises a plurality of compressors (12), an oil separator (13), a liquid storage device (14) and an air intake manifold (11) arranged in parallel, wherein the plurality of compressor exhaust pipes (121) are all connected to the inlet of the oil separator (13) through the exhaust manifold (1), the air outlet of the oil separator (13) is connected to the air inlet of the evaporative condenser through the exhaust pipe (2), the liquid storage device (14) is connected to the liquid outlet of the evaporative condenser through the liquid outlet pipe (7), and the liquid storage device (14) is connected to the end / end of the evaporative condenser through the liquid supply pipe (10). The barrel pump is connected to the liquid inlet, and the return air main pipe of the terminal / barrel pump is connected to the suction manifold (11). The suction manifold (11) includes a heat exchange pipe and a circular pipe (112) with both ends closed. The heat exchange pipe is arranged in the circular pipe (112). The two open ends of the heat exchange pipe pass through an end plate of the circular pipe (112) from the inside to the outside. One open end of the heat exchange pipe is connected to the oil outlet of the oil separator (13), and the other open end is connected to the return oil pipe (6). The return oil pipe (6) is connected to the oil inlets of multiple compressors.

2. A parallel compressor unit according to claim 1, characterized in that: The heat exchange tube is a first U-shaped bend tube (111), the two open ends of the first U-shaped bend tube (111) are respectively connected to the oil outlet of the oil separator (13) and the oil return tube (6), a gas-liquid inlet tube (113) and a plurality of gas outlet tubes (14) are provided on the outer wall of the circular tube (112), the gas-liquid inlet tube (113) and the plurality of gas outlet tubes (14) are respectively connected to the circular tube (112), the gas return main tube of the terminal / barrel pump is connected to the gas-liquid inlet tube (113), the number of gas outlet tubes (14) is the same as the number of compressors (12), the plurality of gas outlet tubes (114) are arranged at intervals, and the plurality of gas outlet tubes (114) are connected to the gas inlets of the plurality of compressors (12) in a one-to-one correspondence.

3. A parallel compressor unit, characterized in that: The invention comprises a plurality of compressors (12), an oil separator (13), a liquid storage tank (14) and an air intake manifold (11) arranged in parallel, wherein the plurality of compressor exhaust pipes (121) are all connected to the inlet of the oil separator (13) through the exhaust manifold (1), the air outlet of the oil separator (13) is connected to the air inlet of the evaporative condenser through the exhaust pipe (2), the liquid storage tank (14) is connected to the liquid outlet of the evaporative condenser through the liquid outlet pipe (7), and the return air main pipe of the terminal / barrel pump is connected to the air intake manifold (11). ), the air intake manifold (11) comprises a heat exchange tube and a circular tube (112) with both ends closed, the heat exchange tube being arranged in the circular tube (112), the two open ends of the heat exchange tube passing through an end plate of the circular tube (112) from the inside to the outside, the liquid storage container (14) being connected to an open end of the heat exchange tube through a liquid supply tube (10), and the other open end being connected to a liquid supply subcooling tube (17) on a liquid supply port of a terminal / barrel pump, and the gas outlet of the air intake manifold (11) being connected to a plurality of compressor refrigerant inlets.

4. A parallel compressor unit according to claim 3, characterized in that: The heat exchange tube is a second U-shaped bend tube (111), and the two open ends of the second U-shaped bend tube (111) are respectively connected to the liquid supply tube (10) and the liquid supply cooling tube (17). A gas-liquid inlet tube (113) and a plurality of gas outlet tubes (114) are provided on the outer wall of the circular tube (112). The gas-liquid inlet tube (113) and the plurality of gas outlet tubes (114) are respectively connected to the circular tube (112). The return air main pipe of the terminal / barrel pump unit is connected to the gas-liquid inlet tube (113). The number of gas outlet tubes (114) is the same as the number of compressors (12). The plurality of gas outlet tubes (114) are arranged at intervals, and the plurality of gas outlet tubes (114) are connected to the gas inlets of the plurality of compressors (12) in a one-to-one correspondence.

5. A parallel compressor unit, characterized in that: The invention comprises a plurality of compressors (12), an oil separator (13), a liquid storage device (14) and an air intake manifold (11) arranged in parallel, wherein the plurality of compressor exhaust pipes (121) are all connected to the inlet of the oil separator (13) through the exhaust manifold (1), the air outlet of the oil separator (13) is connected to the air inlet of the evaporative condenser through the exhaust pipe (2), the liquid storage device (14) is connected to the liquid outlet of the evaporative condenser through the liquid outlet pipe (7), the return air main pipe of the terminal / barrel pump is connected to the air intake manifold (11), the air intake manifold (111) comprises two heat exchange tubes and a circular tube (112) with both ends closed, and the two heat exchange tubes are connected to the inlet of the evaporative condenser through the exhaust pipe (2). The heat exchange tubes are arranged in the circular tube (112), and the two open ends of the two heat exchange tubes are both passed through an end plate of the circular tube (112) from the inside to the outside. One open end of one of the heat exchange tubes is connected to the oil outlet of the oil separator (13), and the other open end is connected to the oil return pipe (6). The oil return pipe (6) is connected to the oil inlet of multiple compressors; the liquid storage tank (14) is connected to one open end of the other heat exchange tube through the liquid supply pipe (10), and the other open end is connected to the liquid supply subcooling pipe (17) on the liquid supply port of the terminal / barrel pump. The gas outlet of the suction manifold (11) is connected to the refrigerant inlet of multiple compressors.

6. A parallel compressor unit according to claim 5, characterized in that: The two heat exchange tubes are respectively a first U-shaped bend (111) and a second U-shaped bend (115); two ends of the first U-shaped bend (111) are respectively connected to the oil outlet of the oil separator (13) and the oil return pipe (6); two ends of the second U-shaped bend (111) are respectively connected to the liquid supply pipe (10) and the liquid supply subcooling pipe (17) on the liquid supply port of the terminal / barrel pump; a gas-liquid inlet pipe (113) and a plurality of gas outlet pipes (14) are provided on the outer wall of the circular tube (112); the gas-liquid inlet pipe (113) and the plurality of gas outlet pipes (14) are respectively connected to the circular tube (112); the terminal / barrel pump return air main pipe is connected to the gas-liquid inlet pipe (113); the number of gas outlet pipes (14) is the same as the number of compressors (12); the plurality of gas outlet pipes (114) are arranged at intervals; and the plurality of gas outlet pipes (114) are connected to the gas inlets of the plurality of compressors (12) in a one-to-one correspondence.

7. A parallel compressor unit according to claim 2 or 6, characterized in that: An open end of the first U-shaped bend (111) and the oil outlet of the oil separator (13) are connected in sequence along the oil flow direction through an oil supply pipe (3) and an oil inlet pipe (4); the other open end of the first U-shaped bend (111) is connected to an oil return pipe (6) through an oil outlet pipe, an end of the oil supply pipe (3) away from the oil separator (13) is connected to a port of an end of the oil inlet pipe (4) away from the air intake manifold (11); and an end of the oil outlet pipe away from the air intake manifold (11) is connected to a port at one end of the oil return pipe (6).

8. A parallel compressor unit according to claim 2 or 6, characterized in that: An open end of the U-shaped bend pipe (111) and the oil outlet of the oil separator (13) are connected in sequence along the oil flow direction through an oil supply pipe (3) and an oil inlet pipe (4); the oil supply pipe (3) is also connected to a first inlet of an oil mixing valve (9); the other open end of the first U-shaped bend pipe (111) is connected to a second inlet of the oil mixing valve (9) through an oil outlet pipe; and the outlet of the oil mixing valve (9) is connected to the oil return pipe (6).

9. A parallel compressor unit according to claim 8, characterized in that: A temperature sensor (15) is provided on one side of the oil return pipe (6) close to the oil mixing valve (9), and a solenoid valve (16) is provided on the oil supply pipe (3). The temperature sensor (15) and the solenoid valve (16) are connected to the PLC control of the unit.

10. A parallel compressor unit according to any one of claims 1 to 9, characterized in that: The liquid reservoir (14) is also connected to a balance pipe (8), and one end of the balance pipe (8) away from the liquid reservoir (14) is connected to the inlet of the evaporative cooling exhaust main pipe.

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