PET polyester spinning system and application thereof

Abstract

The invention discloses a PET polyester spinning system and application thereof, the system comprises a polyester subsystem and a spinning subsystem, the polyester subsystem comprises an ethylene glycol evaporator, an ethylene glycol conveying pipeline, a first melt conveying pipeline and an ethylene glycol evaporation heat medium circulating pump; the spinning subsystem comprises a second melt conveying pipeline, a melt booster pump, a melt cooler, a melt cooling heat medium circulating pump and a third melt conveying pipeline; one end of a circulating low-temperature secondary heating medium supply pipeline of the heating medium serial connection pipeline is communicated with the ethylene glycol heating medium circulating pipeline, and the other end is communicated with the melt heating medium circulating pipeline; one end of the circulating low-temperature secondary heating medium return pipeline communicates with the ethylene glycol heating medium circulating pipeline, and the other end of the circulating low-temperature secondary heating medium return pipeline communicates with the melt heating medium circulating pipeline. By recycling the waste heat in the PET polymer melt conveying process, the environment of a spinning production workshop is improved, and the use amount of a heating medium for primary heating of an ethylene glycol evaporation system is reduced, so that energy conservation and consumption reduction are realized, and the green, low-carbon and environment-friendly effects are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of polyester chemical fiber, and in particular to a PET polyester spinning system and application thereof. Background Art

[0002] In the existing PET polymer melt direct spinning production process, during the PET polymer melt conveying process, the heat generated by the melt flow and the additional temperature rise through the booster pump needs to be removed in time to ensure that the melt maintains a relatively reasonable conveying temperature, thereby avoiding the impact of excessive temperature during the melt conveying process on the quality of the spinning product. Conventional technology usually uses a melt cooler for cooling, and the cooling medium is a secondary circulation heat medium. The secondary circulation heat medium usually uses finned tubes to exchange heat with ambient air to achieve the purpose of cooling and heat removal. The heat is dissipated into the environment, which not only increases the ambient temperature of the workshop, but also wastes fuel. Summary of the invention

[0003] In view of the above problems, the present invention is proposed to provide a PET polyester spinning system and its application which overcomes the above problems or at least partially solves the above problems.

[0004] In a first aspect, an embodiment of the present invention provides a PET polyester spinning system, which may include: a polyester subsystem and a spinning subsystem, wherein the polyester subsystem and the spinning subsystem are connected via a heat medium series pipe;

[0005] The polyester subsystem includes: an ethylene glycol evaporator, an ethylene glycol delivery pipeline, a first melt delivery pipeline and an ethylene glycol evaporation heat medium circulation pump; the ethylene glycol delivery pipeline is connected to the bottom of the ethylene glycol evaporator through an ethylene glycol supply pipeline; the first melt delivery pipeline is connected to the top gas outlet of the ethylene glycol evaporator through an ethylene glycol vapor pipeline; the ethylene glycol evaporation heat medium circulation pump is respectively connected to the inlet and outlet of the inner coil in the ethylene glycol evaporator through the ethylene glycol heat medium circulation pipeline;

[0006] The spinning subsystem includes: a second melt delivery pipeline, a melt booster pump, a melt cooler, a melt cooling heat medium circulation pump and a third melt delivery pipeline; the second melt delivery pipeline, the melt booster pump, the melt cooler and the third melt delivery pipeline are sequentially connected through a melt delivery pipeline; the melt cooling heat medium circulation pump is respectively connected to the inlet and outlet of the inner coil in the melt cooler through the melt heat medium circulation pipeline;

[0007] The heat medium series pipeline includes: a circulating low-temperature secondary heat medium supply pipeline and a circulating low-temperature secondary heat medium return pipeline. One end of the circulating low-temperature secondary heat medium supply pipeline is connected to the ethylene glycol heat medium circulation pipeline near the outlet of the ethylene glycol evaporation heat medium circulation pump, and the other end is connected to the melt heat medium circulation pipeline near the inlet of the melt cooling heat medium circulation pump; one end of the circulating low-temperature secondary heat medium return pipeline is connected to the ethylene glycol heat medium circulation pipeline near the outlet of the inner coil in the ethylene glycol evaporator, and the other end is connected to the melt heat medium circulation pipeline near the outlet of the inner coil in the melt cooler.

[0008] Optionally, the polyester subsystem may further include: a first heat medium filling and conveying pipeline, a first heat medium conveying pipeline and a heat medium recovery pipeline; the first heat medium filling and conveying pipeline is connected to the ethylene glycol heat medium circulation pipeline near the inlet of the ethylene glycol evaporation heat medium circulation pump; the first heat medium conveying pipeline is connected to the ethylene glycol heat medium circulation pipeline near the outlet of the ethylene glycol evaporation heat medium circulation pump through a first temperature controller; the heat medium recovery pipeline is connected to the ethylene glycol heat medium circulation pipeline near the outlet of the inner coil in the ethylene glycol evaporator.

[0009] Optionally, a first valve is further provided between the first heat medium filling and conveying pipeline and the ethylene glycol heat medium circulation pipeline;

[0010] A second valve is provided between the first heat medium delivery pipeline and the first temperature controller, wherein the inlet end of the second valve is connected to the first heat medium delivery pipeline, one outlet end is connected to the first temperature controller, and the other outlet end is close to the inlet of the ethylene glycol evaporation heat medium circulation pump and is connected to the ethylene glycol heat medium circulation pipeline;

[0011] A third valve is provided on the ethylene glycol heat medium circulation pipeline between the ethylene glycol evaporation heat medium circulation pump and the ethylene glycol evaporator, the inlet end of the third valve is connected to the outlet of the ethylene glycol evaporation heat medium circulation pump, one outlet end is connected to the inlet of the inner coil in the ethylene glycol evaporator, and the other outlet end is closed; and / or,

[0012] The ethylene glycol heat medium circulation pipelines at both inlet and outlet ends of the ethylene glycol evaporation heat medium circulation pump are connected in parallel and are provided with a fourth valve.

[0013] Optionally, a fifth valve is provided on the ethylene glycol supply pipeline;

[0014] The polyester subsystem may further include: a liquid level indicating controller, a sixth valve and a seventh valve; one end of the liquid level indicating controller is connected to the bottom of the ethylene glycol evaporator through the sixth valve, and the other end is connected to the top of the ethylene glycol evaporator through the seventh valve;

[0015] The inlet end of the fifth valve is communicated with the ethylene glycol delivery pipeline, one outlet end is communicated with the bottom of the ethylene glycol evaporator, and the other outlet end is communicated with the liquid level indicating controller.

[0016] Optionally, the system may further include: a second temperature controller, wherein the second temperature controller is connected to the ethylene glycol evaporator.

[0017] Optionally, the spinning subsystem may also include: a second heat medium filling and conveying pipeline and a second heat medium conveying pipeline; the second heat medium filling and conveying pipeline is connected to the melt heat medium circulation pipeline near the outlet of the melt cooling heat medium circulation pump, and the second heat medium conveying pipeline is connected to the melt heat medium circulation pipeline near the inlet of the melt cooling heat medium circulation pump.

[0018] Optionally, an eighth valve is further provided between the second heat medium filling and conveying pipeline and the melt heat medium circulation pipeline;

[0019] A ninth valve and a third temperature controller are further provided between the second heat medium filling and conveying pipeline and the melt heat medium circulation pipeline; the inlet end of the ninth valve is connected to the second heat medium filling and conveying pipeline, one outlet end of the ninth valve is connected to the third temperature controller and then connected to the melt heat medium circulation pipeline near the outlet of the melt cooling heat medium circulation pump, and the other outlet end is connected to the melt heat medium circulation pipeline near the inlet of the melt cooling heat medium circulation pump; and / or,

[0020] The melt cooling heat medium circulation pipelines at both ends of the inlet and outlet of the melt cooling heat medium circulation pump are connected in parallel and are provided with a tenth valve.

[0021] Optionally, the system may further include: a circulating low-temperature secondary heat medium delivery pipeline and a circulating low-temperature secondary heat medium delivery pipeline;

[0022] The circulating low-temperature secondary heat medium transport pipeline is in communication with the circulating low-temperature secondary heat medium supply pipeline, and the circulating low-temperature secondary heat medium transport pipeline is in communication with the circulating low-temperature secondary heat medium return pipeline.

[0023] Optionally, the system may further include: an eleventh valve disposed in a parallel pipeline between the circulating low-temperature secondary heat medium supply pipeline and the circulating low-temperature secondary heat medium return pipeline;

[0024] The twelfth valve, the thirteenth valve and the fourteenth valve are sequentially arranged on the circulating low-temperature secondary heat medium supply pipeline; the twelfth valve and the thirteenth valve are located on both sides of the parallel pipeline, the fourteenth valve is close to the melt heat medium circulation pipeline, the inlet end of the fourteenth valve is connected to the circulating low-temperature secondary heat medium supply pipeline, one outlet end is close to the inlet of the melt cooling heat medium circulation pump and is connected to the melt heat medium circulation pipeline, and the other outlet end is close to the outlet of the melt cooling heat medium circulation pump and is connected to the melt heat medium circulation pipeline;

[0025] and / or,

[0026] A fifteenth valve is arranged on the circulating low-temperature secondary heat medium return pipeline.

[0027] In a second aspect, an embodiment of the present invention provides an application of the PET polyester spinning system described in the first aspect in a polyester spinning process.

[0028] The beneficial effects of the above technical solution provided in the embodiments of the present invention include at least:

[0029] The embodiment of the present invention provides a PET polyester spinning system and its application, which recycles the waste heat in the PET polymer melt conveying process, improves the spinning production workshop environment, and reduces the use of heat medium for primary heating of the ethylene glycol evaporation system, thereby achieving energy saving and consumption reduction, and achieving a green, low-carbon and environmentally friendly effect.

[0030] The embodiment of the present invention targets the heat generated by the flow of the polymer melt and the additional temperature rise generated by the booster pump during the transportation of the polymer melt. After the circulating secondary heat medium (hydrogenated terphenyl) exchanges heat with the PET melt through the melt cooler, it is used as a supplementary heat source for heating the ethylene glycol evaporation heat medium in the polyester workshop (polyester subsystem). The heat is completely recovered and utilized in the ethylene glycol evaporation heating system, instead of using conventional fin tubes and ambient air heat exchange cooling measures. Specifically, a low-temperature heat medium dry pipe (circulating low-temperature secondary heat medium supply pipeline) is connected from the outlet of the ethylene glycol evaporation heat medium circulation pump as a cold source for the melt cooler. The secondary heat medium after heat exchange in the melt cooler returns to the inlet of the ethylene glycol evaporation heat medium circulation pump, and a low-temperature secondary heat medium circulation system powered by the ethylene glycol evaporation heat medium circulation pump is established. The heat load of the melt cooler is taken out to supplement the ethylene glycol evaporator heating system, thereby saving the amount of primary heat medium used in the ethylene glycol evaporator.

[0031] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description and the accompanying drawings.

[0032] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0034] Figure 1 It is a structural diagram of a PET polyester spinning system provided in an embodiment of the present invention;

[0035] Among them, 1-polyester subsystem; 2-spinning subsystem; 3-heat medium series pipe line;

[0036] 101-ethylene glycol evaporator; 102-ethylene glycol delivery pipeline; 103-first melt delivery pipeline; 104-ethylene glycol evaporation heat medium circulation pump; 105-ethylene glycol supply pipeline; 106-ethylene glycol vapor pipeline; 107-ethylene glycol heat medium circulation pipeline; 108-first heat medium filling delivery pipeline; 109-first heat medium delivery pipeline; 110-heat medium recovery pipeline; 111-first temperature controller; 112-first valve; 113-second valve; 114-third valve; 115-fourth valve; 116-fifth valve; 117-liquid level indicator controller; 118-sixth valve; 119-seventh valve; 120-second temperature controller;

[0037] 201-second melt delivery pipeline; 202-melt booster pump; 203-melt cooler; 204-melt cooling heat medium circulation pump; 205-third melt delivery pipeline; 206-melt heat medium circulation pipeline; 207-second heat medium filling delivery pipeline; 208-second heat medium delivery pipeline; 209-eighth valve; 210-ninth valve; 211-third temperature controller; 212-tenth valve;

[0038] 31-circulating low-temperature secondary heat medium supply pipeline; 32-circulating low-temperature secondary heat medium return pipeline; 33-first circulating low-temperature secondary heat medium transport pipeline; 34-second circulating low-temperature secondary heat medium transport pipeline; 35-eleventh valve; 36-twelfth valve; 37-thirteenth valve; 38-fourteenth valve; 39-fifteenth valve. DETAILED DESCRIPTION

[0039] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0040] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", "far", "near", "front", "back" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0041] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0042] A PET polyester spinning system is provided in an embodiment of the present invention, referring to Figure 1 As shown, the system may include: a polyester subsystem 1 and a spinning subsystem 2, wherein the polyester subsystem 1 and the spinning subsystem 2 are connected via a heat medium series pipe 3;

[0043] The polyester subsystem 1 may include: an ethylene glycol evaporator 101, an ethylene glycol delivery pipeline 102, a first melt delivery pipeline 103 and an ethylene glycol evaporation heat medium circulation pump 104; the ethylene glycol delivery pipeline 102 is connected to the bottom of the ethylene glycol evaporator 101 through an ethylene glycol supply pipeline 105; the first melt delivery pipeline 103 is connected to the top gas outlet of the ethylene glycol evaporator 101 through an ethylene glycol vapor pipeline 106; the ethylene glycol evaporation heat medium circulation pump 104 is respectively connected to the inlet and outlet of the inner coil (not shown in the figure) in the ethylene glycol evaporator 101 through an ethylene glycol heat medium circulation pipeline 107;

[0044] The spinning subsystem 2 may include: a second melt delivery pipeline 201, a melt booster pump 202, a melt cooler 203, a melt cooling heat medium circulation pump 204 and a third melt delivery pipeline 205; the second melt delivery pipeline 201, the melt booster pump 202, the melt cooler 203 and the third melt delivery pipeline 205 are sequentially connected through the melt delivery pipeline; the melt cooling heat medium circulation pump 204 is respectively connected to the inlet and outlet of the inner coil (not shown in the figure) in the melt cooler 203 through the melt heat medium circulation pipeline 206;

[0045] The heat medium series pipeline 3 may include: a circulating low-temperature secondary heat medium supply pipeline 31 and a circulating low-temperature secondary heat medium return pipeline 32. One end of the circulating low-temperature secondary heat medium supply pipeline 31 is connected to the ethylene glycol heat medium circulation pipeline 107 near the outlet of the ethylene glycol evaporation heat medium circulation pump 104, and the other end is connected to the melt heat medium circulation pipeline 206 near the inlet of the melt cooling heat medium circulation pump 204; one end of the circulating low-temperature secondary heat medium return pipeline 32 is connected to the ethylene glycol heat medium circulation pipeline 107 near the outlet of the inner coil in the ethylene glycol evaporator 101, and the other end is connected to the melt heat medium circulation pipeline 206 near the outlet of the inner coil in the melt cooler 203.

[0046] It should be noted that, refer to Figure 1 As shown, there are at least two third melt delivery pipelines 205 in the embodiment of the present invention, and the melt delivery pipeline between the third melt delivery pipeline 205 and the melt cooler 203 is inclined so that the melt in the pipeline is discharged into the third melt delivery pipeline 205 under the action of gravity. The delivery pipeline is a connected upstream and downstream pipeline system, which is not specifically limited in this embodiment.

[0047] The above-mentioned system provided in the embodiment of the present invention recycles the waste heat in the PET polymer melt conveying process, thereby improving the spinning production workshop environment and reducing the use of heat medium for primary heating of the ethylene glycol evaporation system, thereby achieving energy saving and consumption reduction and achieving a green, low-carbon and environmentally friendly effect.

[0048] The embodiment of the present invention targets the heat generated by the flow of the polymer melt and the additional temperature rise generated by the booster pump during the transportation of the polymer melt. After the circulating secondary heat medium (hydrogenated terphenyl) exchanges heat with the PET melt through the melt cooler, it is used as a supplementary heat source for heating the ethylene glycol evaporation heat medium in the polyester workshop (polyester subsystem). The heat is completely recovered and utilized in the ethylene glycol evaporation heating system, instead of using conventional fin tubes and ambient air heat exchange cooling measures. Specifically, a low-temperature heat medium dry pipe (circulating low-temperature secondary heat medium supply pipeline) is connected from the outlet of the ethylene glycol evaporation heat medium circulation pump as a cold source for the melt cooler. The secondary heat medium after heat exchange in the melt cooler returns to the inlet of the ethylene glycol evaporation heat medium circulation pump, and a low-temperature secondary heat medium circulation system powered by the ethylene glycol evaporation heat medium circulation pump is established. The heat load of the melt cooler is taken out to supplement the ethylene glycol evaporator heating system, thereby saving the amount of primary heat medium used in the ethylene glycol evaporator.

[0049] In an alternative embodiment, referring to Figure 1As shown, the polyester subsystem 1 may further include: a first heat medium filling and conveying pipeline 108, a first heat medium conveying pipeline 109 and a heat medium recovery pipeline 110; the first heat medium filling and conveying pipeline 108 is connected to the ethylene glycol heat medium circulation pipeline 107 near the inlet of the ethylene glycol evaporation heat medium circulation pump 104; the first heat medium conveying pipeline 109 is connected to the ethylene glycol heat medium circulation pipeline 107 near the outlet of the ethylene glycol evaporation heat medium circulation pump 104 through the first temperature controller 111; the heat medium recovery pipeline 110 is connected to the ethylene glycol heat medium circulation pipeline 107 near the outlet of the inner coil in the ethylene glycol evaporator 101.

[0050] The first temperature controller in the embodiment of the present invention performs temperature range control on the circulating low-temperature secondary heat medium used to take heat from the melt cooler and the primary heat medium in the first heat medium delivery pipeline, so that the required circulating secondary heat medium temperature can be accurately controlled according to the melt process parameter requirements. The circulating secondary heat medium after heat exchange from the melt cooler in the above system carries heat back to the pump inlet return pipe of the ethylene glycol evaporation circulating heat medium system as a supplementary heat source for the ethylene glycol evaporation heat medium, realizing heat recovery and utilization while improving the operating environment of the production workshop.

[0051] In another alternative embodiment, referring to Figure 1 As shown, a first valve 112 is further provided between the first heat medium filling and conveying pipeline 108 and the glycol heat medium circulation pipeline 107. The first valve in the embodiment of the present invention may be a ball valve;

[0052] A second valve 113 is provided between the first heat medium delivery pipeline 109 and the first temperature controller 111. The second valve in this embodiment is a pneumatic valve, specifically a two-position three-way pneumatic valve. The inlet end of the second valve 113 is connected to the first heat medium delivery pipeline 109, one outlet end is connected to the first temperature controller 111, and the other outlet end is close to the inlet of the ethylene glycol evaporation heat medium circulation pump 104 and is connected to the ethylene glycol heat medium circulation pipeline 107;

[0053] A third valve 114 is provided on the ethylene glycol heat medium circulation pipeline 107 between the ethylene glycol evaporation heat medium circulation pump 104 and the ethylene glycol evaporator 101. In this embodiment, the third valve is a pneumatic valve. The inlet end of the third valve 114 is connected to the outlet of the ethylene glycol evaporation heat medium circulation pump 104, one outlet end is connected to the inlet of the inner coil in the ethylene glycol evaporator 101, and the other outlet end is closed; and / or,

[0054] The ethylene glycol heat medium circulation pipelines 107 at both inlet and outlet ends of the ethylene glycol evaporation heat medium circulation pump 104 are connected in parallel and are provided with a fourth valve 115 .

[0055] The arrow marked on the valve body of the fourth valve 115 in this embodiment is the recommended pressure-bearing direction of the valve. The pressure-bearing direction refers to the direction of the arrow on the valve body when the valve is in a closed state after being applied to pipeline working conditions. If it is installed incorrectly, the valve may not close tightly and leakage may occur.

[0056] In another alternative embodiment, referring to Figure 1 As shown, a fifth valve 116 is provided on the ethylene glycol supply pipeline 105. The fifth valve in this embodiment is a pneumatic valve;

[0057] The polyester subsystem 1 may further include: a liquid level indicating controller 117, a sixth valve 118 and a seventh valve 119; one end of the liquid level indicating controller 117 is connected to the bottom of the ethylene glycol evaporator 101 through the sixth valve 118, and the other end is connected to the top of the ethylene glycol evaporator 101 through the seventh valve 119;

[0058] An inlet end of the fifth valve 116 is communicated with the ethylene glycol delivery pipeline 102 , one outlet end is communicated with the bottom of the ethylene glycol evaporator 101 , and the other outlet end is communicated with the liquid level indicating controller 117 .

[0059] The sixth valve and the seventh valve in this embodiment are ball valves, which can effectively open and close the pipeline.

[0060] In another alternative embodiment, referring to Figure 1 As shown, the system may further include: a second temperature controller 120 , which is in communication with the ethylene glycol evaporator 101 .

[0061] In another alternative embodiment, referring to Figure 1 As shown, the spinning subsystem 2 may further include: a second heat medium filling and conveying pipeline 207 and a second heat medium conveying pipeline 208; the second heat medium filling and conveying pipeline 207 is connected to the melt heat medium circulation pipeline 206 near the outlet of the melt cooling heat medium circulation pump 204, and the second heat medium conveying pipeline 208 is connected to the melt heat medium circulation pipeline 206 near the inlet of the melt cooling heat medium circulation pump 204.

[0062] In another alternative embodiment, referring to Figure 1 As shown, an eighth valve 209 is further provided between the second heat medium filling and conveying pipeline 208 and the melt heat medium circulation pipeline 206. The eighth valve in this embodiment is a ball valve;

[0063] A ninth valve 210 and a third temperature controller 211 are also provided between the second heat medium filling and conveying pipeline 207 and the melt heat medium circulation pipeline 206; the ninth valve in this embodiment is a two-position three-way pneumatic valve, the inlet end of the ninth valve 210 is connected to the second heat medium filling and conveying pipeline 207, one outlet end of the ninth valve 210 is connected to the third temperature controller 211 and then connected to the melt heat medium circulation pipeline 206 near the outlet of the melt cooling heat medium circulation pump 204, and the other outlet end is connected to the melt heat medium circulation pipeline 206 near the inlet of the melt cooling heat medium circulation pump 204; and / or,

[0064] The melt cooling heat medium circulation pipelines 206 at both ends of the inlet and outlet of the melt cooling heat medium circulation pump 204 are connected in parallel and are provided with a tenth valve 212 .

[0065] The arrow marked on the valve body of the tenth valve in this embodiment is the recommended pressure-bearing direction of the valve. The pressure-bearing direction refers to the direction of the arrow on the valve body when the valve is in a closed state after being applied to pipeline working conditions. If it is installed incorrectly, the valve may not close tightly and leakage may occur.

[0066] In another alternative embodiment, referring to Figure 1 As shown, the system may further include: a first circulation low-temperature secondary heat medium transport pipeline 33 and a second circulation low-temperature secondary heat medium transport pipeline 34;

[0067] The first circulating low-temperature secondary heat medium transport pipeline 33 is connected to the circulating low-temperature secondary heat medium supply pipeline 31 , and the second circulating low-temperature secondary heat medium transport pipeline 34 is connected to the circulating low-temperature secondary heat medium return pipeline 32 .

[0068] In another alternative embodiment, referring to Figure 1 As shown, the system may further include: an eleventh valve 35 disposed in a parallel pipeline (not marked in the figure) between the circulating low-temperature secondary heat medium supply pipeline 31 and the circulating low-temperature secondary heat medium return pipeline 32. The eleventh valve in this embodiment is a ball valve;

[0069] The twelfth valve 36, the thirteenth valve 37 and the fourteenth valve 38 are sequentially arranged on the circulating low-temperature secondary heat medium supply pipeline 31; the twelfth valve 36 and the thirteenth valve 37 are located on both sides of the parallel pipeline, the fourteenth valve 38 is close to the melt heat medium circulation pipeline 206, the inlet end of the fourteenth valve 38 is connected to the circulating low-temperature secondary heat medium supply pipeline 31, one outlet end is close to the inlet of the melt cooling heat medium circulation pump 204 and is connected to the melt heat medium circulation pipeline 206, and the other outlet end is close to the outlet of the melt cooling heat medium circulation pump 204 and is connected to the melt heat medium circulation pipeline 206;

[0070] and / or,

[0071] A fifteenth valve 39 is provided on the circulating low-temperature secondary heat medium return pipeline 32 .

[0072] In this embodiment, the twelfth valve and the thirteenth valve are ball valves, the fourteenth valve is a two-position three-way pneumatic valve, and the fifteenth valve is a ball valve.

[0073] The above-mentioned PET polyester spinning system provided in the embodiment of the present invention has a wide range of application prospects in polyester chemical fiber production enterprises. Taking a 300,000 tons / year polyester spinning production device as an example, the annual energy-saving operating cost can be nearly 1 million yuan. By eliminating the finned tubes used for direct heat dissipation between the production workshop and the ambient air, the ambient temperature of the workshop is improved. Furthermore, the embodiment of the present invention not only recycles the waste heat in the PET melt conveying process, but also has a positive effect on the transformation of the environment and the energy saving and consumption reduction of the enterprise, so it can be widely used in polyester chemical fiber and synthetic material enterprises.

[0074] In a specific example, a project of an enterprise with an annual output of 600,000 tons of intelligent, low-carbon differentiated fibers is taken as an example. The project has been fully put into use and is operating well.

[0075] 1. Energy saving and consumption reduction: All five conveying lines have been put into use. Considering the increased energy consumption of the glycol heat medium pump due to this scheme, the annual recovery energy is roughly estimated to be (238kW-35kW)*8000h*0.61 yuan / kWh=990,600 yuan / year compared with the previous conventional design, and the annual operating cost can be saved by nearly one million yuan. If the glycol heat medium pump of the subsequent device adopts frequency conversion control and optimizes the pump parameters, the energy saving effect is estimated to be better.

[0076] Among them: 1) 238kW is the heat load that needs to be removed from the four melt coolers (based on the Sulzer data sheet and converted by coefficient according to the actual device);

[0077] 2) 35kW is the energy consumption of the polyester glycol evaporation heat medium circulation pump increased by this solution.

[0078] 2. Investment: Each melt conveying line can reduce 6 sets of finned tube air coolers 6*0.55*5=16.5 (million yuan); considering the increase of circulating low-temperature secondary heat medium regulating valve group and circulating low-temperature secondary heat medium carbon steel pipelines in spinning and polyester workshops, it is about 2.5*5=12.5 (million yuan); 16.5-12.5=4 (million yuan). The overall investment will be slightly reduced by applying recycling energy-saving technology.

[0079] 3. Workshop ambient temperature: After the finned tube air cooler is not put into use or eliminated, the on-site inspection shows that the workshop ambient temperature is slightly lower by 1 to 2°C, and the temperature of the pipe rack or wall of the finned tube air cooler is slightly lower by more than 4 to 5°C.

[0080] Based on the same inventive concept, an embodiment of the present invention further provides an application of the above-mentioned PET polyester spinning system in a polyester spinning process.

[0081] The beneficial effects and specific description of the application of the above-mentioned PET polyester spinning system in the polyester spinning process can be referred to the relevant introduction of the above-mentioned system, and the embodiments of the present invention will not be repeated here.

[0082] Obviously, various changes and modifications may be made to the present invention by those skilled in the art without departing from the spirit and scope of the present invention. The present disclosure is not limited to the precise structure described above and shown in the accompanying drawings, and various changes and modifications may be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims. Thus, if these changes and modifications of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these changes and modifications.

Claims

1. A PET polyester spinning system, characterized in that: include: A polyester subsystem and a spinning subsystem, wherein the polyester subsystem and the spinning subsystem are connected via a heat medium series pipe; The polyester subsystem includes: an ethylene glycol evaporator, an ethylene glycol delivery pipeline, a first melt delivery pipeline and an ethylene glycol evaporation heat medium circulation pump; the ethylene glycol delivery pipeline is connected to the bottom of the ethylene glycol evaporator through an ethylene glycol supply pipeline; the first melt delivery pipeline is connected to the top gas outlet of the ethylene glycol evaporator through an ethylene glycol vapor pipeline; the ethylene glycol evaporation heat medium circulation pump is respectively connected to the inlet and outlet of the inner coil in the ethylene glycol evaporator through the ethylene glycol heat medium circulation pipeline; The spinning subsystem includes: a second melt delivery pipeline, a melt booster pump, a melt cooler, a melt cooling heat medium circulation pump and a third melt delivery pipeline; the second melt delivery pipeline, the melt booster pump, the melt cooler and the third melt delivery pipeline are sequentially connected through a melt delivery pipeline; the melt cooling heat medium circulation pump is respectively connected to the inlet and outlet of the inner coil in the melt cooler through the melt heat medium circulation pipeline; The heat medium series pipeline includes: a circulating low-temperature secondary heat medium supply pipeline and a circulating low-temperature secondary heat medium return pipeline. One end of the circulating low-temperature secondary heat medium supply pipeline is connected to the ethylene glycol heat medium circulation pipeline near the outlet of the ethylene glycol evaporation heat medium circulation pump, and the other end is connected to the melt heat medium circulation pipeline near the inlet of the melt cooling heat medium circulation pump; one end of the circulating low-temperature secondary heat medium return pipeline is connected to the ethylene glycol heat medium circulation pipeline near the outlet of the inner coil in the ethylene glycol evaporator, and the other end is connected to the melt heat medium circulation pipeline near the outlet of the inner coil in the melt cooler.

2. The system according to claim 1, characterized in that The polyester subsystem also includes: a first heat medium filling and conveying pipeline, a first heat medium conveying pipeline and a heat medium recovery pipeline; the first heat medium filling and conveying pipeline is connected to the ethylene glycol heat medium circulation pipeline near the inlet of the ethylene glycol evaporation heat medium circulation pump; the first heat medium conveying pipeline is connected to the ethylene glycol heat medium circulation pipeline near the outlet of the ethylene glycol evaporation heat medium circulation pump through a first temperature controller; the heat medium recovery pipeline is connected to the ethylene glycol heat medium circulation pipeline near the outlet of the inner coil in the ethylene glycol evaporator.

3. The system according to claim 2, characterized in that A first valve is also provided between the first heat medium filling and conveying pipeline and the ethylene glycol heat medium circulation pipeline; A second valve is provided between the first heat medium delivery pipeline and the first temperature controller, wherein the inlet end of the second valve is connected to the first heat medium delivery pipeline, one outlet end is connected to the first temperature controller, and the other outlet end is close to the inlet of the ethylene glycol evaporation heat medium circulation pump and is connected to the ethylene glycol heat medium circulation pipeline; A third valve is provided on the ethylene glycol heat medium circulation pipeline between the ethylene glycol evaporation heat medium circulation pump and the ethylene glycol evaporator, the inlet end of the third valve is connected to the outlet of the ethylene glycol evaporation heat medium circulation pump, one outlet end is connected to the inlet of the inner coil in the ethylene glycol evaporator, and the other outlet end is closed; and / or, The ethylene glycol heat medium circulation pipelines at both inlet and outlet ends of the ethylene glycol evaporation heat medium circulation pump are connected in parallel and are provided with a fourth valve.

4. The system according to claim 2, characterized in that A fifth valve is provided on the ethylene glycol supply pipeline; The polyester subsystem further includes: a liquid level indicating controller, a sixth valve and a seventh valve; one end of the liquid level indicating controller is connected to the bottom of the ethylene glycol evaporator through the sixth valve, and the other end is connected to the top of the ethylene glycol evaporator through the seventh valve; The inlet end of the fifth valve is communicated with the ethylene glycol delivery pipeline, one outlet end is communicated with the bottom of the ethylene glycol evaporator, and the other outlet end is communicated with the liquid level indicating controller.

5. The system according to claim 2, characterized in that Also includes: A second temperature controller is communicated with the ethylene glycol evaporator.

6. The system according to claim 1, characterized in that The spinning subsystem also includes: a second heat medium filling and conveying pipeline and a second heat medium conveying pipeline; the second heat medium filling and conveying pipeline is connected to the melt heat medium circulation pipeline near the outlet of the melt cooling heat medium circulation pump, and the second heat medium conveying pipeline is connected to the melt heat medium circulation pipeline near the inlet of the melt cooling heat medium circulation pump.

7. The system according to claim 6, characterized in that An eighth valve is also provided between the second heat medium filling and conveying pipeline and the melt heat medium circulation pipeline; A ninth valve and a third temperature controller are further provided between the second heat medium filling and conveying pipeline and the melt heat medium circulation pipeline; the inlet end of the ninth valve is connected to the second heat medium filling and conveying pipeline, one outlet end of the ninth valve is connected to the third temperature controller and then connected to the melt heat medium circulation pipeline near the outlet of the melt cooling heat medium circulation pump, and the other outlet end is connected to the melt heat medium circulation pipeline near the inlet of the melt cooling heat medium circulation pump; and / or, The melt cooling heat medium circulation pipelines at both ends of the inlet and outlet of the melt cooling heat medium circulation pump are connected in parallel and are provided with a tenth valve.

8. The system according to any one of claims 1 to 7, characterized in that: Also includes: A first-circulation low-temperature secondary heat medium transport pipeline and a second-circulation low-temperature secondary heat medium transport pipeline; The first circulating low-temperature secondary heat medium transport pipeline is connected to the circulating low-temperature secondary heat medium supply pipeline, and the second circulating low-temperature secondary heat medium transport pipeline is connected to the circulating low-temperature secondary heat medium return pipeline.

9. The system according to claim 8, characterized in that Also includes: an eleventh valve disposed in a parallel pipeline between the circulating low-temperature secondary heat medium supply pipeline and the circulating low-temperature secondary heat medium return pipeline; The twelfth valve, the thirteenth valve and the fourteenth valve are sequentially arranged on the circulating low-temperature secondary heat medium supply pipeline; the twelfth valve and the thirteenth valve are located on both sides of the parallel pipeline, the fourteenth valve is close to the melt heat medium circulation pipeline, the inlet end of the fourteenth valve is connected to the circulating low-temperature secondary heat medium supply pipeline, one outlet end is close to the inlet of the melt cooling heat medium circulation pump and is connected to the melt heat medium circulation pipeline, and the other outlet end is close to the outlet of the melt cooling heat medium circulation pump and is connected to the melt heat medium circulation pipeline; and / or, A fifteenth valve is arranged on the circulating low-temperature secondary heat medium return pipeline.

10. Use of the PET polyester spinning system according to any one of claims 1 to 9 in a polyester spinning process.

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