阅读说明：本技术 多台螺杆压缩机氨冷凝系统、油冷却系统联合运行的方法 (Method for jointly operating ammonia condensation system and oil cooling system of multiple screw compressors ) 是由 李勇 谭长弓 黄土金 于 2021-10-11 设计创作，主要内容包括：本发明涉及压缩机技术领域,具体涉及多台螺杆压缩机氨冷凝系统、油冷却系统联合运行的方法；包括一号氨冷凝器、一号贮氨器、一号油冷器、一号压缩机、二号氨冷凝器、二号贮氨器、二号油冷器以及二号压缩机,所述一号氨冷凝器的输出端与一号贮氨器的输入端之间连通设置有液氨输送管；本发明通过气氨管线与控制阀门的设置,可通过对控制阀门的开启,来保证一号压缩机与二号压缩机的正常运行,且本发明较现有技术,具有改动幅度小,易于操作的特点,从而使得氨冷凝系统、油冷却系统并联,实现互联互通,互相备用,这样即使其中一套冷凝系统故障,也可运行另一套冷凝系统,从而保证一号压缩机与二号压缩机的正常运行,极大提高生产安全性。(The invention relates to the technical field of compressors, in particular to a method for jointly operating an ammonia condensation system and an oil cooling system of a plurality of screw compressors; the ammonia cooling system comprises a first ammonia condenser, a first ammonia storage device, a first oil cooler, a first compressor, a second ammonia condenser, a second ammonia storage device, a second oil cooler and a second compressor, wherein a liquid ammonia conveying pipe is communicated between the output end of the first ammonia condenser and the input end of the first ammonia storage device; the invention can ensure the normal operation of the first compressor and the second compressor by opening the control valve through the arrangement of the gas ammonia pipeline and the control valve, and compared with the prior art, the invention has the characteristics of small change range and easy operation, thereby leading the ammonia condensing system and the oil cooling system to be connected in parallel, realizing interconnection and intercommunication and mutual standby, leading one set of condensing system to be capable of operating the other set of condensing system even if the other set of condensing system fails, further ensuring the normal operation of the first compressor and the second compressor, and greatly improving the production safety.)

1. A combined operation device of a plurality of screw compressor ammonia condensing systems and oil cooling systems comprises an ammonia condenser (1), an ammonia storage device (2), an oil cooler (3), a compressor (4), an ammonia storage device (5), an ammonia storage device (6), an oil cooler (7) and a compressor (8), and is characterized in that a liquid ammonia conveying pipe (17) is communicated between the output end of the ammonia condenser (1) and the input end of the ammonia storage device (2), the output end of the ammonia storage device (2) and the input end of the oil cooler (3) are communicated through the liquid ammonia conveying pipe (17), the output end of the ammonia storage device (5) and the input end of the ammonia storage device (6) and the input end of the oil cooler (7) are communicated through the liquid ammonia conveying pipe (17), the intercommunication is provided with No. two gas ammonia conveyer pipes (10) between the output of the input of one side of an ammonia condenser (1) and one side of an oil cooler (3), the input of one side of No. two ammonia condensers (5) and the output of one side of No. two oil coolers (7) are through No. two gas ammonia conveyer pipes (10) intercommunication, the intercommunication is provided with gas ammonia pipeline (15) between No. two gas ammonia conveyer pipes (10) on an ammonia condenser (1) and No. two ammonia condensers (5), communicate through gas ammonia pipeline (15) between the output of an ammonia storage ware (2) and the liquid ammonia conveyer pipe (17) on the output of No. two ammonia storage ware (6), all be provided with control flap (16) on gas ammonia pipeline (15).

2. The combined operation device of the ammonia condensation system and the oil cooling system of the multiple screw compressors according to claim 1, wherein output oil pipes (12) are respectively communicated between the output end of the first oil cooler (3) and the input end of the first compressor (4) and between the output end of the second oil cooler (7) and the input end of the second compressor (8).

3. The combined operation device of the ammonia condensation system and the oil cooling system of the multiple screw compressors according to claim 1, wherein an input oil pipe (13) is communicated between the output end of the first compressor (4) and the input end of the first oil cooler (3) and between the output end of the second compressor (8) and the input end of the second oil cooler (7), and oil filters (14) are arranged on the output oil pipe (12) and the input oil pipe (13).

4. The combined operation device for the ammonia condensing system and the oil cooling system of the multiple screw compressors according to claim 1, wherein the output end of the first compressor (4) is communicated with the input end of the side, away from the second gas ammonia conveying pipe (10), of the first ammonia condenser (1) to form a first gas ammonia conveying pipe (9), and the output end of the second compressor (8) is communicated with the input end of the side, away from the second gas ammonia conveying pipe (10), of the second ammonia condenser (5) to form a first gas ammonia conveying pipe (9).

5. The combined operation device for the ammonia condensation system and the oil cooling system of the multiple screw compressors according to claim 1, wherein pressure detectors (11) are arranged on the first gas ammonia conveying pipe (9) and the second gas ammonia conveying pipe (10).

6. The combined operation device of the ammonia condensation system and the oil cooling system of the multiple screw compressors according to claim 5, wherein the input end of the lower end of the first compressor (4) and the input end of the lower end of the second compressor (8) are both communicated with a third gas ammonia conveying pipe (19).

7. The combined operation device for the ammonia condensation system and the oil cooling system of the multiple screw compressors according to claim 5, wherein a leakage detector (18) is arranged at the joint of the two ends of the liquid ammonia delivery pipe (17).

8. A method for jointly operating an ammonia condensation system and an oil cooling system of a plurality of screw compressors, which is characterized in that the device for jointly operating the ammonia condensation system and the oil cooling system of the plurality of screw compressors according to any one of claims 1 to 7 is used, and comprises the following steps:

s1, starting a first ammonia condenser (1), a first ammonia storage device (2), a first oil cooler (3), a first compressor (4), a second ammonia condenser (5), a second ammonia storage device (6), a second oil cooler (7) and a second compressor (8);

s2, liquefying ammonia gas by the first ammonia condenser (1) and the second ammonia condenser (5), and respectively delivering the liquid ammonia to the first ammonia storage device (2) and the second ammonia storage device (6) through a liquid ammonia delivery pipe (17);

s3, the first ammonia storage device (2) and the second ammonia storage device (6) respectively convey liquid ammonia to the first oil cooler (3) and the second oil cooler (7) through liquid ammonia conveying pipes (17);

s4, gasifying liquid ammonia by the first oil cooler (3) and the second oil cooler (7), respectively conveying the gasified liquid ammonia to the first ammonia condenser (1) and the second ammonia condenser (5) through a second gas ammonia conveying pipe (10), and exchanging oil between the first oil cooler (3) and the first compressor (4) and between the second oil cooler (7) and the second compressor (8) through an output oil pipe (12) and an input oil pipe (13);

s5, the first compressor (4) and the second compressor (8) respectively convey gas ammonia to the first ammonia condenser (1) and the second ammonia condenser (5) through the first gas ammonia conveying pipe (9), and simultaneously gas ammonia is input into the first compressor (4) and the second compressor (8) through the third gas ammonia conveying pipe (19).

9. The method for the combined operation of the ammonia condensing system and the oil cooling system of the multi-screw compressor according to claim 8, wherein in the step S1, when the ammonia condenser I (1) or the ammonia condenser II (5) is damaged, the control valve (16) is opened, so that the ammonia gas in the ammonia gas conveying pipe II (10) enters the undamaged ammonia condenser II (5) or the ammonia condenser I (1) through the ammonia gas pipeline (15), and then the ammonia gas conveying pipe (17) at the output end of the ammonia storage device I (2) or the ammonia storage device II (6) conveys the ammonia gas into the oil cooler I (3) or the oil cooler II (7) through the ammonia gas pipeline (15).

10. The method for jointly operating the ammonia condensing system and the oil cooling system of the multi-screw compressor according to claim 8, wherein in the step S1, when the first oil cooler (3) or the second oil cooler (7) is damaged, the control valve (16) is opened, the gas ammonia in the second gas ammonia delivery pipe (10) of the second oil cooler (7) or the first oil cooler (3) enters the first ammonia condenser (1) and the second ammonia condenser (5) through the gas ammonia pipeline (15), and the liquid ammonia is delivered to the first oil cooler (3) or the second oil cooler (7) through the gas ammonia pipeline (15) between the liquid ammonia delivery pipes (17).

Technical Field

The invention relates to the technical field of compressors, in particular to a method for jointly operating an ammonia condensation system and an oil cooling system of a plurality of screw compressors.

Background

A compressor is a driven fluid machine that raises low-pressure gas into high-pressure gas, and is a heart of a refrigeration system. The refrigeration cycle comprises a gas suction pipe, a motor, a piston, an exhaust pipe, a compression pipe, a condensation pipe, an expansion pipe, an evaporation pipe, a heat exchange pipe and a heat exchange pipe. The compressors are classified into piston compressors, screw compressors, centrifugal compressors, linear compressors, and the like. The terms introduce the working principle, classification, accessories, specifications, operation requirements, production, common faults and environmental protection requirements, model selection principle, installation conditions and development trend of the compressor.

The ammonia screw compressor utilizes the lubricating oil to lubricate the rotor running at a high speed, reduce the temperature and reduce the noise in the running process, so that the lubricating oil can be heated, and the liquefied ammonia of the self condensation system cools and reduces the temperature of the lubricating oil, thereby ensuring the normal running of the compressor.

In the prior art, in two sets of high-low pressure system compressors, independent oil cooling systems are respectively arranged, the production requirement can be met under the normal condition, if one set of ammonia condensing system fails to operate, condensed liquid ammonia is not used for cooling lubricating oil, so that the other set of compressor cannot operate, and hidden dangers or even accidents can be brought to production.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides a method for jointly operating an ammonia condensing system and an oil cooling system of a plurality of screw compressors, and the method can ensure the normal operation of a first compressor and a second compressor by opening a control valve through the arrangement of a gas ammonia pipeline and the control valve.

In order to achieve the purpose, the invention provides the following technical scheme:

a method for combined operation of an ammonia condensing system and an oil cooling system of a plurality of screw compressors comprises a first ammonia condenser, a first ammonia storage device, a first oil cooler, a first compressor, a second ammonia condenser, a second ammonia storage device, a second oil cooler and a second compressor, wherein a liquid ammonia conveying pipe is communicated between the output end of the first ammonia condenser and the input end of the first ammonia storage device, the output end of the first ammonia storage device is communicated with the input end of the first oil cooler through a liquid ammonia conveying pipe, the output end of the second ammonia condenser and the input end of the second ammonia storage device are communicated with the input end of the second oil cooler through liquid ammonia conveying pipes, a second gas ammonia conveying pipe is communicated between the input end of one side of the first ammonia condenser and the output end of one side of the first oil cooler, the input end of one side of the second ammonia condenser and the output end of one side of the second oil cooler are communicated through a second gas ammonia conveying pipe, the intercommunication is provided with the gas ammonia pipeline between No. two gas ammonia conveyer pipes on ammonia condenser and No. two ammonia condensers, communicate through the gas ammonia pipeline between the output of an ammonia storage ware and the liquid ammonia conveyer pipe on the output of No. two ammonia storage ware, all be provided with control flap on the gas ammonia pipeline.

The invention is further configured to: output oil pipes are communicated between the output end of the first oil cooler and the input end of the first compressor and between the output end of the second oil cooler and the input end of the second compressor.

The invention is further configured to: all feed through between the output of a compressor and the input of an oil cooler and between the output of No. two compressors and the input of No. two oil coolers and be provided with input oil pipe, all be provided with fluid filter on output oil pipe and the input oil pipe.

The invention is further configured to: the output of a compressor and the input intercommunication of one side that No. two gas ammonia conveyer pipes were kept away from to ammonia condenser are provided with a gas ammonia conveyer pipe, the output of No. two compressors and the input of one side that No. two gas ammonia conveyer pipes were kept away from to No. two ammonia condensers communicate through a gas ammonia conveyer pipe.

The invention is further configured to: and pressure detectors are arranged on the first gas ammonia conveying pipe and the second gas ammonia conveying pipe.

The invention is further configured to: the input of the lower extreme of a compressor and the input of the lower extreme of No. two compressors all communicate and are provided with No. three gas ammonia conveyer pipes.

The invention is further configured to: and leakage detectors are arranged at the joints of the two ends of the liquid ammonia delivery pipe.

The method for jointly operating the ammonia condensation system and the oil cooling system of the plurality of screw compressors comprises the following steps:

s1, starting the first ammonia condenser, the first ammonia storage device, the first oil cooler, the first compressor, the second ammonia condenser, the second ammonia storage device, the second oil cooler and the second compressor;

s2, liquefying ammonia gas by the first ammonia condenser and the second ammonia condenser, and respectively conveying liquid ammonia to the first ammonia storage device and the second ammonia storage device through liquid ammonia conveying pipes;

s3, respectively conveying liquid ammonia to the first oil cooler and the second oil cooler through liquid ammonia conveying pipes by the first ammonia storage device and the second ammonia storage device;

s4, gasifying liquid ammonia through the first oil cooler and the second oil cooler, respectively conveying the gasified liquid ammonia to the first ammonia condenser and the second ammonia condenser through the second gas ammonia conveying pipe, and exchanging oil between the first oil cooler and the first compressor and between the second oil cooler and the second compressor through an output oil pipe and an input oil pipe;

s5, the first compressor and the second compressor respectively convey gas ammonia to the first ammonia condenser and the second ammonia condenser through the first gas ammonia conveying pipe, and simultaneously gas ammonia is input into the first compressor and the second compressor through the third gas ammonia conveying pipe.

The invention is further configured to: and in the step S, if the first ammonia condenser or the second ammonia condenser is damaged, the control valve is opened, so that the gas ammonia in the second gas ammonia conveying pipe enters the second ammonia condenser or the first ammonia condenser which is not damaged through a gas ammonia pipeline, and then the liquid ammonia conveying pipe at the output end of the first ammonia storage device or the second ammonia storage device inputs the liquid ammonia into the first oil cooler or the second oil cooler through the gas ammonia pipeline.

The invention is further configured to: and S, when the first oil cooler or the second oil cooler is damaged, the control valve is opened, gas ammonia in a second gas ammonia conveying pipe on the second oil cooler or the first oil cooler enters the first ammonia condenser and the second ammonia condenser through a gas ammonia pipeline, and liquid ammonia is conveyed to the first oil cooler or the second oil cooler through the gas ammonia pipeline between liquid ammonia conveying pipes.

Advantageous effects

Compared with the known public technology, the technical scheme provided by the invention has the following beneficial effects:

the invention can ensure the normal operation of the first compressor and the second compressor by opening the control valve through the arrangement of the gas ammonia pipeline and the control valve, and compared with the prior art, the invention has the characteristics of small change range and easy operation, thereby leading the ammonia condensing system and the oil cooling system to be connected in parallel, realizing interconnection and intercommunication and being mutually standby, thus even if one set of condensing system fails, the other set of condensing system can be operated, thereby ensuring the normal operation of the first compressor and the second compressor, greatly improving the production safety, detecting the pressure value of the gas ammonia through the arrangement of the pressure detector, adjusting the entering amount of the gas ammonia through the change of the pressure value, simultaneously detecting whether the first gas ammonia conveying pipe leaks or not, increasing the sealing performance of the liquid ammonia conveying pipe through the arrangement of the leakage detector, and simultaneously through the arrangement of the oil liquid filter, the oil can be filtered, so that the impurity content in the oil in the process of oil delivery is reduced, and the service life of the invention is prolonged.

Drawings

FIG. 1 is a diagram of a method for jointly operating an ammonia condensing system and an oil cooling system of a plurality of screw compressors.

In the figure: 1. ammonia condenser No. one; 2. an ammonia storage tank I; 3. a first oil cooler; 4. a first compressor; 5. ammonia condenser II; 6. a second ammonia storage device; 7. a second oil cooler; 8. a second compressor; 9. a first gas ammonia delivery pipe; 10. a second gas ammonia delivery pipe; 11. a pressure detector; 12. an output oil pipe; 13. inputting an oil pipe; 14. an oil filter; 15. a gas ammonia line; 16. a control valve; 17. a liquid ammonia delivery pipe; 18. a leak detector; 19. and a third gas ammonia conveying pipe.

Detailed Description

The following further describes embodiments of the present invention with reference to the drawings. It should be noted that the description of the embodiments is provided to help understanding of the present invention, but the present invention is not limited thereto. In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention; the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance; furthermore, unless expressly stated or limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, as they may be fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Example 1

Referring to fig. 1, the combined operation device of the multiple screw compressors ammonia condensing system and the oil cooling system comprises a first ammonia condenser 1, a first ammonia storage device 2, a first oil cooler 3, a first compressor 4, a second ammonia condenser 5, a second ammonia storage device 6, a second oil cooler 7 and a second compressor 8, and is characterized in that a liquid ammonia delivery pipe 17 is communicated between the output end of the first ammonia condenser 1 and the input end of the first ammonia storage device 2, the output end of the first ammonia storage device 2 is communicated with the input end of the first oil cooler 3 through the liquid ammonia delivery pipe 17, the output end of the second ammonia condenser 5 is communicated with the input end of the second ammonia storage device 6 and the input end of the second ammonia storage device 6 are communicated with the input end of the second oil cooler 7 through the liquid ammonia delivery pipe 17, a second gas ammonia delivery pipe 10 is communicated between the input end of one side of the first ammonia condenser 1 and the output end of one side of the first oil cooler 3, the input of No. two ammonia condenser 5's one side and the output of No. two oil cooler 7's one side are through No. two gas ammonia conveyer pipes 10 intercommunication, and the intercommunication is provided with gas ammonia pipeline 15 between No. two gas ammonia conveyer pipes 10 on No. one ammonia condenser 1 and No. two ammonia condenser 5, and the intercommunication is carried out through gas ammonia pipeline 15 between the liquid ammonia conveyer pipe 17 on the output of No. one ammonia storage ware 2 and No. two ammonia storage ware 6, all is provided with control valve 16 on the gas ammonia pipeline 15.

Output oil pipes 12 are communicated between the output end of the first oil cooler 3 and the input end of the first compressor 4 and between the output end of the second oil cooler 7 and the input end of the second compressor 8. An input oil pipe 13 is communicated between the output end of the first compressor 4 and the input end of the first oil cooler 3 and between the output end of the second compressor 8 and the input end of the second oil cooler 7, and an oil filter 14 is arranged on the output oil pipe 12 and the input oil pipe 13.

The output of a compressor 4 and the input intercommunication of the one side that No. two gas ammonia conveyer pipes 10 were kept away from to ammonia condenser 1 are provided with a gas ammonia conveyer pipe 9, and the output of No. two compressors 8 and the input of the one side that No. two gas ammonia conveyer pipes 10 were kept away from to No. two ammonia condenser 5 communicate through a gas ammonia conveyer pipe 9.

And pressure detectors 11 are arranged on the first gas ammonia conveying pipe 9 and the second gas ammonia conveying pipe 10.

The input end of the lower end of the first compressor 4 and the input end of the lower end of the second compressor 8 are both communicated with a third gas ammonia delivery pipe 19.

And leakage detectors 18 are arranged at the joints of the two ends of the liquid ammonia delivery pipe 17.

When the invention is used, through the arrangement of the control valve 16 and the control valve 16, when in use, if any one of the first ammonia condenser 1, the second ammonia condenser 5, the first oil cooler 3 and the second oil cooler 7 is damaged, the communication of the gas ammonia pipelines 15 can be controlled through the control valve 16, so that the liquid ammonia among the gas ammonia pipelines 15 on the liquid ammonia conveying pipe 17 is intercommunicated, the gas ammonia intercommunication among the gas ammonia pipelines 15 on the second gas ammonia conveying pipe 10 is realized, the system interconnection among the first ammonia condenser 1, the first ammonia storage 2, the second ammonia condenser 5 and the second ammonia storage 6 is realized, the systems among the first oil cooler 3, the first compressor 4, the second oil cooler 7 and the second compressor 8 are connected in parallel, the interconnection and the mutual standby are realized, thus, even if one of the condensing systems fails, the other condensing system can be operated, and the normal operation of the first compressor 4 and the second compressor 8 is ensured, thereby greatly improve the production security, simultaneously through the setting of pressure measurement appearance 11, can detect the pressure value of gas ammonia, through the change of pressure value, the volume of the entering of adjustable gas ammonia, detectable gas ammonia conveyer pipe 9 is leaked simultaneously, through the setting of leak detector 18, can increase the leakproofness of liquid ammonia conveyer pipe 17, simultaneously through the setting of fluid filter 14, can filter fluid to reduce the impurity content in the fluid that fluid goes out the transmission, thereby increase the life of the invention.

The invention also provides a method for jointly operating the ammonia condensation system and the oil cooling system of the plurality of screw compressors, which comprises the following steps:

step one, starting a first ammonia condenser 1, a first ammonia storage device 2, a first oil cooler 3, a first compressor 4, a second ammonia condenser 5, a second ammonia storage device 6, a second oil cooler 7 and a second compressor 8.

And step two, liquefying the gas ammonia by the first ammonia condenser 1 and the second ammonia condenser 5, and respectively delivering the liquid ammonia to the first ammonia storage device 2 and the second ammonia storage device 6 through a liquid ammonia delivery pipe 17.

And step three, the ammonia storage device 2 and the ammonia storage device 6 respectively transport liquid ammonia to the oil cooler 3 and the oil cooler 7 through the liquid ammonia transport pipe 17.

And step four, liquid ammonia is gasified by the first oil cooler 3 and the second oil cooler 7, and then is respectively conveyed to the first ammonia condenser 1 and the second ammonia condenser 5 through the second gas ammonia conveying pipe 10, and meanwhile, oil is exchanged between the first oil cooler 3 and the first compressor 4 and between the second oil cooler 7 and the second compressor 8 through the output oil pipe 12 and the input oil pipe 13.

And step five, the first compressor 4 and the second compressor 8 respectively convey the gas ammonia to the first ammonia condenser 1 and the second ammonia condenser 5 through the first gas ammonia conveying pipe 9, and simultaneously the gas ammonia is input into the first compressor 4 and the second compressor 8 through the third gas ammonia conveying pipe 19.

In the first step, if the first ammonia condenser 1 or the second ammonia condenser 5 is damaged, the control valve 16 is opened, so that the gas ammonia in the second gas ammonia conveying pipe 10 enters the undamaged second ammonia condenser 5 or the first ammonia condenser 1 through the gas ammonia pipeline 15, and then the liquid ammonia conveying pipe 17 at the output end of the first ammonia storage device 2 or the second ammonia storage device 6 conveys the liquid ammonia into the first oil cooler 3 or the second oil cooler 7 through the gas ammonia pipeline 15.

In the first step, if the first oil cooler 3 or the second oil cooler 7 is damaged, the control valve 16 is opened, the gas ammonia in the second gas ammonia delivery pipe 10 on the second oil cooler 7 or the first oil cooler 3 enters the first ammonia condenser 1 and the second ammonia condenser 5 through the gas ammonia pipeline 15, and then the liquid ammonia is delivered to the first oil cooler 3 or the second oil cooler 7 through the gas ammonia pipeline 15 between the liquid ammonia delivery pipes 17.

According to the invention, through the arrangement of the gas ammonia pipeline 15 and the control valve 16, the normal operation of the first compressor 4 and the second compressor 8 can be ensured through the opening of the control valve 16, and compared with the prior art, the invention has the characteristics of small change range and easiness in operation, so that the ammonia condensing system and the oil cooling system are connected in parallel, the interconnection and intercommunication are realized, and the mutual standby is realized, therefore, even if one set of condensing system fails, the other set of condensing system can be operated, the normal operation of the first compressor 4 and the second compressor 8 is ensured, and the production safety is greatly improved.

The above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the corresponding technical solutions.