A mold heating control system and method

Abstract

The present invention relates to the field of mold temperature control technology, and in particular to a mold heating control system and method, the system comprising: a plurality of mold roller groups, which are divided into a preheating section, a heating section, a heat preservation section and a cooling section in sequence according to the forward direction of the foam material; a mold entry oil circuit; a first connecting oil circuit, which contains a plurality of first connecting pipes; a second connecting oil circuit, which contains a plurality of second connecting pipes; a merging point; an oil return oil circuit; a third connecting oil circuit, which contains a plurality of third connecting pipes and is also provided with a heating regulating valve; a temperature control oil circuit, which is provided with a temperature control regulating valve and a plurality of heat exchangers, and a cooling regulating valve, which is provided between the temperature control oil circuit and the oil return oil circuit; and an oil unloading oil circuit, which is provided with an oil unloading valve. The present invention can effectively and accurately control the foaming temperature in the foam production process and ensure the quality of the foam material product.

Description

Technical Field

[0001] The present invention relates to the technical field of mold temperature control, and in particular to a mold heating control system and method. Background Art

[0002] Foam materials are widely used in packaging, insulation, cushioning and other fields. In order to produce foam products with high quality and consistency, temperature control plays a vital role in the foaming process. Especially in the process of using mold rollers to form foam, temperature fluctuations will directly affect the density, thickness and surface quality of the foam material. Therefore, accurate and stable temperature control technology has become a key research direction in the foam production process. In the existing mold roller heating system, there are the following deficiencies: In the complex foam material production process, there are large differences in temperature requirements at different stages, and it is difficult for the existing system to accurately control the temperature difference according to the specific requirements of each stage. Summary of the invention

[0003] The present invention provides a mold heating control system and method, which can effectively solve the problems in the background technology.

[0004] The present invention provides a mold heating control system, comprising:

[0005] Multiple mold roller groups are distributed along the traveling direction of the foam material; each mold roller group includes two rollers arranged one above the other, an oil channel is arranged inside the roller, and the foam material passes through the two rollers;

[0006] The plurality of mold rollers are grouped into a preheating section, a heating section, a heat preservation section and a cooling section according to the advancing direction of the foam material;

[0007] The mold oil circuit directs hot oil into the mold roller group in the heating section;

[0008] A first connecting oil circuit, comprising a plurality of first connecting pipes, capable of connecting the oil passages of two adjacent mold roller groups in the preheating section, so that the oil flowing out of the heating section flows into the mold roller group of the preheating section in sequence in the opposite direction of the advancing direction of the foam material;

[0009] The second connecting oil circuit includes a plurality of second connecting pipes, which can connect the oil passages of two adjacent mold roller groups in the heat preservation section, so that the oil flowing out of the heating section flows into the mold roller group of the heat preservation section in sequence along the advancing direction of the foam material;

[0010] The oil flowing out of the first connecting oil passage and the second connecting oil passage merges at a merging point;

[0011] Oil return line, used for oil return;

[0012] The third connecting oil circuit includes a plurality of third connecting pipes, which can connect the oil passages of two adjacent mold roller groups in the heat preservation section, so that the oil flowing out from the merging point flows into the mold roller group of the cooling section in sequence along the advancing direction of the foam material, and finally flows into the oil return circuit; the third connecting oil circuit is provided with a heating regulating valve between the merging point and the cooling section;

[0013] The temperature control oil circuit has two ends respectively connected to the merging point and the outlet of the third connecting oil circuit; the temperature control oil circuit is provided with a temperature control regulating valve and a plurality of heat exchangers, and the temperature control regulating valve is arranged at the inlet of the temperature control oil circuit; the heat exchanger is arranged in the middle section of the temperature control oil circuit, and is used to exchange heat with the third connecting oil circuit;

[0014] A temperature-lowering regulating valve is arranged between the temperature-control oil circuit and the oil return oil circuit;

[0015] The oil unloading oil circuit is connected to the temperature control oil circuit and the oil return oil circuit, and the connection point with the temperature control oil circuit is located between the temperature control regulating valve and the heat exchanger; the oil unloading oil circuit is provided with an oil unloading valve.

[0016] Furthermore, a mixer is provided at the merging point for mixing the hot oil flowing out of the first connecting oil passage and the second connecting oil passage.

[0017] Furthermore, the temperature control oil circuit includes an oil guide oil circuit which is arranged in parallel with the heat exchanger, and a temperature regulating valve is arranged on the oil guide oil circuit.

[0018] Furthermore, a radiator is provided on the temperature control oil circuit, and the radiator is between the heat exchanger and the outlet of the third connecting oil circuit.

[0019] Furthermore, it is characterized in that an oil pump is installed in the oil return line.

[0020] Furthermore, each oil inlet and oil outlet of the mold roller group is provided with a heating temperature sensor.

[0021] Furthermore, each inlet and outlet of each heat exchanger is provided with a temperature control temperature sensor.

[0022] The present invention also provides a mold heating control method, using the above mold heating control system, comprising:

[0023] Normal mode: adjust the heating regulating valve and the temperature control regulating valve to make the hot oil in the oil circuit flow evenly into the third connecting oil circuit and the temperature control oil circuit, open the oil unloading valve, adjust the cooling regulating valve to the fully open state, and guide the hot oil into all mold roller groups until the temperature of all mold roller groups is stable;

[0024] Rapid cooling mode: reduce the flow of the cooling regulating valve, so that the flow of the cooling regulating valve is smaller than that of the heating regulating valve, so that the heating oil with lower temperature in each part flows into the temperature control passage;

[0025] Slow cooling mode: Open the cooling regulating valve to the fully open state and close the oil unloading valve; allow part of the hot oil to flow directly into the temperature control passage.

[0026] Furthermore, in the rapid cooling mode, the temperature of each mold roller group corresponding to the cooling section is regulated by adjusting the opening of each temperature regulating valve, so that the approximate temperature of each mold roller group is the same as the set temperature; the specific calculation method of the approximate temperature of each mold roller group is:

[0027] Troller=Tin-Uc·(1-fl)·(1-ft)·(Tin-Tsin);

[0028] in:

[0029] Troller is the approximate temperature of the die roller set;

[0030] Tin is the temperature of the hot oil flowing into the heat exchanger in the third connecting oil circuit;

[0031] Uc is the heat exchange efficiency of the heat exchanger in countercurrent flow;

[0032] fl is the opening ratio of the cooling control valve, 0 is fully closed, and 1 is fully open;

[0033] ft is the opening ratio of the thermostatic control valve, 0 is fully closed and 1 is fully open;

[0034] Tsin is the temperature of the relatively low temperature heating oil flowing into the heat exchanger in the temperature control oil circuit.

[0035] Furthermore, in the slow cooling mode, the temperature of each mold roller group corresponding to the cooling section is regulated by adjusting the opening of each temperature regulating valve, so that the approximate temperature of each mold roller group is the same as the set temperature; the specific calculation method of the approximate temperature of each mold roller group is:

[0036] Troller=Tin+Uf·(1-fl)·[fk / (1-fk)]·(Twar-Tin);

[0037] in:

[0038] Troller is the approximate temperature of the die roller set;

[0039] Tin is the temperature of the hot oil flowing into the heat exchanger in the third connecting oil circuit;

[0040] Uf is the heat exchange efficiency of the heat exchanger in the downstream direction;

[0041] fk is the opening ratio of the temperature control valve, 0 is fully closed, and 1 is fully open;

[0042] fl is the opening ratio of the thermostatic control valve, 0 is fully closed and 1 is fully open;

[0043] Twar is the temperature of the hot oil in the temperature control oil circuit that does not flow through the mold roller group.

[0044] Through the technical solution of the present invention, the following technical effects can be achieved: through the group design of the preheating section, the heating section, the insulation section and the cooling section, and the oil circuit system with independent control of each section, the temperature of the mold roller group can be accurately controlled under different heating and cooling requirements. In addition, through the coordinated setting of the oil circuits, the system only needs to pass through one oil supply point to work, reducing the demand for hot oil in other areas, which helps to optimize the overall energy utilization of the system; at the same time, the stable temperature supply can effectively avoid the deformation or uneven quality of the foam material caused by temperature fluctuations, thereby improving the quality and consistency of processing; fast and slow cooling modes are provided, and by adjusting the combined opening of the cooling regulating valve, the temperature control regulating valve and the temperature regulating regulating valve, two different cooling methods, fast and gentle, can be achieved to meet different process requirements and improve the available range of the process. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0046] Figure 1 It is a structural schematic diagram of the mold heating control system in the present invention;

[0047] Figure 2 It is a schematic diagram of each section of the mold heating control system in the present invention;

[0048] Figure 3 It is a circuit diagram of the mold heating control system in the present invention;

[0049] Figure 4 It is an enlarged view of point A in the present invention;

[0050] Figure 5 It is an enlarged view of point B in the present invention;

[0051] Figure 6 It is a schematic diagram of the hot oil flow method in normal mode in the present invention;

[0052] Figure 7 It is a schematic diagram of the flow method of hot oil in the rapid cooling mode of the present invention;

[0053] Figure 8It is a schematic diagram of the flow method of hot oil in the slow cooling mode of the present invention;

[0054] Attached figures: 1. mold roller group; 1a. preheating section; 1b. heating section; 1c. insulation section; 1d. cooling section; 2. mold entry oil circuit; 3. first connecting oil circuit; 4. second connecting oil circuit; 5. mixer; 6. return oil circuit; 6a. oil pump; 7. third connecting oil circuit; 7a. heating regulating valve; 8. temperature control oil circuit; 8a. temperature control regulating valve; 8b. heat exchanger; 8c. oil guide oil circuit; 8d. temperature control regulating valve; 8e. radiator; 9. cooling regulating valve; 10. oil unloading oil circuit; 10a. oil unloading valve; 11. heating temperature sensor; 12. temperature control temperature sensor. DETAILED DESCRIPTION

[0055] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0056] In the description of the present invention, it should be noted that the orientations or positional relationships indicated by “center”, “up”, “down”, “left”, “right”, “vertical”, “horizontal”, “inside” and “outside”, etc., are based on the orientations 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 referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0057] 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 an indirect connection 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.

[0058] The present invention relates to a mold heating control system, such as Figures 1 to 8 As shown, including:

[0059] Multiple mold roller groups 1 are distributed along the direction of the foam material. Each mold roller group 1 includes two rollers arranged one above the other. Oil channels are arranged in the rollers. Oil flows in and out of the oil channels, thereby changing the temperature of the rollers. The foam material passes through the two rollers. The distance between the two rollers is set according to the thickness requirements of the instant noodle material.

[0060] Multiple mold roller groups 1 are grouped into preheating section 1a, heating section 1b, heat preservation section 1c and cooling section 1d according to the advancing direction of the foam material; there are 1 to 2 mold roller groups 1 in the heating section 1b, and there are multiple mold roller groups 1 in the preheating section 1a, heat preservation section 1c and cooling section 1d. By controlling the temperature of the mold roller group 1 in sections, not only can the whole foaming process be taken into account, but also the requirements of different processing conditions for foam materials of different thicknesses can be met.

[0061] The mold inlet oil circuit 2 is used to introduce hot oil into the mold roller group 1 of the heating section 1b to provide a continuous heat source for the heating process. The mold inlet oil circuit 2 provides an independent heat source for the heating section 1b to ensure that the foam material reaches the required processing temperature in the heating section 1b.

[0062] The first connecting oil circuit 3 contains a plurality of first connecting pipes, which can connect the oil passages of two adjacent mold roller groups 1 in the preheating section 1a, so that the oil flowing out of the heating section 1b flows into the mold roller group 1 of the preheating section 1a in sequence in the opposite direction of the forward direction of the foam material, thereby gradually reducing the temperature of the mold roller group 1 in the preheating section 1a in the opposite direction of the forward direction of the foam material.

[0063] The second connecting oil circuit 4 contains a plurality of second connecting pipes, which can connect the oil passages of two adjacent mold roller groups 1 in the heat preservation section 1c, so that the oil flowing out of the heating section 1b flows into the mold roller group 1 of the heat preservation section 1c in sequence along the advancing direction of the foam material, so that the temperature of the mold roller group 1 in the heat preservation section 1c gradually decreases along the advancing direction of the foam material. The oil flowing out of the first connecting oil circuit 3 and the second connecting oil circuit 4 merge at the merging point, and the hot oil flowing out of the preheating section 1a and the heat preservation section 1c are reunited, reducing heat waste and allowing the remaining heat energy to continue to be used in the subsequent stages.

[0064] The oil return line 6 is used for oil return; the oil return line 6 collects the used hot oil from the system and guides it back to the heating device or the oil tank to form a closed loop circulation.

[0065] The third connecting oil circuit 7 contains a plurality of third connecting pipes, which can connect the oil passages of two adjacent mold roller groups 1 in the heat preservation section 1c, so that the oil flowing out from the merging point flows into the mold roller group 1 of the cooling section 1d in sequence along the advancing direction of the foam material, so that the temperature of the mold roller group 1 in the cooling section 1d gradually decreases along the advancing direction of the foam material, and finally flows into the return oil circuit 6; the third connecting oil circuit 7 is provided with a heating regulating valve 7a between the merging point and the cooling section 1d; the third connecting oil circuit 7 sequentially introduces the hot oil flowing out of the merging point into the mold roller group 1 in the cooling section 1d, so that the hot oil gradually flows into each mold roller in the cooling section 1d, and the purpose of slow cooling is achieved by gradually reducing the temperature of the hot oil.

[0066] Under this structure, the overall mold heating system for heating and foaming the foam material can form the following state: according to the direction of movement of the foam material, it will pass through the preheating section 1a, the heating section 1b, the insulation section 1c and the cooling section 1d in sequence, and the foaming process is as follows:

[0067] The foam material in the preheating section 1a will be gradually heated to ensure that the heat of the outermost layer can be transferred to the middle layer of the foam material, so that the temperature inside and outside the foam material can reach a level close to the foaming temperature before entering the heating section 1b;

[0068] After entering the heating section 1b, the mold roller group 1 of the heating section 1b has the highest temperature, so that the foam material reaches its foaming temperature, and the outermost layer of the foam material begins to foam; due to the foaming and expansion of the outer layer, the heat transfer is isolated to a certain extent. At this time, if the temperature is directly lowered, the center of the foam material will not foam sufficiently due to insufficient heat;

[0069] In order to allow the middle layer of the foam material to accumulate enough heat, a heat preservation section 1c is set in the system. The temperature of the heat preservation section 1c is lower than that of the heating section 1b, so the outermost layer of the foam material that has been foamed will not be burned; and the temperature of the heat preservation section 1c itself will not be too low, so that the heat accumulated in the foam material will not be dissipated outward, so that the middle layer of the foam material is in a "stuffy" state, and this state is used to achieve complete foaming of the middle layer;

[0070] After the foam material is foamed inside and outside, the cooling section 1d can be used to gradually cool the foam material. This section can prevent the foam material from shrinking or wrinkling due to the large temperature difference between the inside and outside, and can effectively improve the product quality of the foam material. In addition, the system only needs to work through one oil supply point through the coordination setting between the oil circuits, reducing the demand for hot oil in other areas, which helps to optimize the overall energy utilization of the system; at the same time, the stable temperature supply can effectively avoid deformation or uneven quality of the foam material caused by temperature fluctuations, thereby improving the quality and consistency of processing.

[0071] In addition to the aforementioned system basic components, there are also the following components:

[0072] The temperature control oil circuit 8 has two ends respectively connected to the merging point and the outlet of the third connecting oil circuit 7; the temperature control oil circuit 8 is provided with a temperature control regulating valve 8a and a plurality of heat exchangers 8b, and the temperature control regulating valve 8a is arranged at the inlet of the temperature control oil circuit 8; the heat exchanger 8b is arranged in the middle section of the temperature control oil circuit 8, and is used to exchange heat with the third connecting oil circuit 7; the temperature control oil circuit 8 exchanges heat with the third connecting oil circuit 7 through the plurality of heat exchangers 8b, and adjusts the temperature of the hot oil flowing into the cooling section 1d in the cooling section 1d, so that the cooling section 1d can adapt to the temperature control requirements of the foam material during the heat dissipation process, and reduce the risk of shrinkage or deformation of the foam material caused by a sudden drop in temperature.

[0073] The cooling regulating valve 9 is arranged between the temperature control oil circuit 8 and the oil return oil circuit 6; the cooling regulating valve 9 can realize switching between multiple control modes by adjusting the flow rate and flow direction of the oil flowing through the temperature control oil circuit 8, thereby improving the applicability of the system.

[0074] The oil unloading circuit 10 connects the temperature control circuit 8 and the oil return circuit 6, and the connection point with the temperature control circuit 8 is located between the temperature control regulating valve 8a and the heat exchanger 8b; the oil unloading circuit 10 is provided with an oil unloading valve 10a. The oil unloading circuit 10 is regulated by the oil unloading valve 10a, and can quickly discharge excess oil, helping the system to reduce internal pressure when needed, and preventing system damage caused by excessive pressure; at the same time, when the thickness of the foam material to be processed is relatively thin, the oil unloading circuit 10 serves as the outflow circuit of the oil flowing into the temperature control circuit 8, ensuring the stability of the system.

[0075] like Figures 1 to 4 As shown, preferably, a mixer is provided at the merging point for mixing the hot oil flowing out of the first connecting oil circuit 3 and the second connecting oil circuit 4 to make the temperature of the two hot oil circuits uniform, avoid local overheating or cooling caused by inconsistent oil temperatures, and provide a more stable oil temperature benchmark for subsequent temperature control processes.

[0076] Preferably, the temperature control oil circuit 8 includes an oil guide oil circuit 8c arranged in parallel with the heat exchanger 8b, and a temperature regulating valve 8d is arranged on the oil guide oil circuit 8c. The oil guide oil circuit 8c provides a bypass for the heat exchanger 8b, so that the oil can flow without passing through the heat exchanger 8b; the temperature regulating valve 8d allows the flow of the oil guide oil circuit 8c to be accurately adjusted, and the proportion of the oil entering the heat exchanger 8b is changed, thereby refining the temperature control of the overall system.

[0077] like Figures 1 to 4 As shown, a radiator 8e is also provided on the temperature control oil circuit 8, and the radiator 8e is between the heat exchanger 8b and the outlet of the third connecting oil circuit 7. The radiator 8e is used to additionally cool the oil that is about to enter the heat exchanger 8b, so that the temperature of the hot oil in the third connecting oil circuit 7 becomes lower after the heat exchange is completed, so as to ensure the surface quality of the system when processing thin foam materials.

[0078] like Figure 3 As shown, preferably, an oil pump 6a is installed in the oil return line 6. The oil pump 6a can accelerate the flow of oil in the oil return line 6, quickly return the cooled oil to the oil tank or the main circulation system, and maintain the smoothness of the oil line; and the oil pump 6a can keep the pressure of the oil return line 6 constant, prevent the oil in the oil return line 6 from having insufficient flow rate due to gravity or pipeline resistance, and ensure the normal circulation of the system.

[0079] like Figure 5 As shown, preferably, each oil inlet and outlet of each mold roller set 1 is provided with a heating temperature sensor 11. The temperature sensor monitors the temperature of the oil when it enters and leaves the mold roller in real time, helping to understand the heating status of each mold roller set 1. Through the temperature data fed back by the sensor, the temperature setting of each section can be adjusted more accurately to ensure that the mold roller set 1 is kept within the most suitable working temperature range.

[0080] like Figure 5 As shown, preferably, each inlet and outlet of each heat exchanger 8b is provided with a temperature control temperature sensor 12, which can accurately monitor the temperature of the oil when entering and leaving each heat exchanger 8b in real time, and provide more detailed temperature data.

[0081] The present invention also relates to a mold heating control method divided into three modes, using the above mold heating control system, the steps comprising:

[0082] like Figure 6 As shown, in normal mode: adjust the heating regulating valve 7a and the temperature control regulating valve 8a, so that the hot oil in the oil circuit flows evenly into the third connecting oil circuit 7 and the temperature control oil circuit 8, open the oil unloading valve 10a, adjust the cooling regulating valve 9 to a fully open state, and introduce the hot oil into all the mold roller groups 1 until the temperature of all the mold roller groups 1 is stable;

[0083] When the thickness of the foam material to be processed is moderate, and the temperature conditions required for processing the foam material are consistent with the temperature conditions of each group in the normal mode, the normal mode is adopted for processing.

[0084] In normal mode, the hot oil is evenly distributed to each oil circuit through the reasonable regulation of the heating regulating valve 7a and the temperature control regulating valve 8a; by opening the oil unloading valve 10a, the two oil circuits do not interfere with each other, thereby achieving a more linear cooling curve; after the temperature of all mold roller groups 1 is stabilized, the processing temperature of the foam material is easier to control, ensuring the quality and consistency of the product.

[0085] like Figure 7 As shown, in the rapid cooling mode: reduce the flow of the cooling regulating valve 9, so that the flow of the cooling regulating valve 9 is smaller than that of the heating regulating valve 7a, so that the heating oil with lower temperature in each part flows into the temperature control oil circuit 8;

[0086] When the thickness of the foam material to be processed is relatively thin, in order to avoid heat accumulation inside the foam material, the foam material should be processed in a rapid cooling mode; in the rapid cooling mode, by reducing the flow of the cooling regulating valve 9 and making the flow of the cooling regulating valve 9 smaller than the heating regulating valve 7a, a portion of the hot oil that has completed heating the mold roller group 1 and is blocked by the cooling regulating valve 9 and cannot enter the return oil circuit 6 flows into the temperature control oil circuit 8, generating heat exchange with the hot oil that is about to flow into the mold roller group 1.

[0087] The hot oil flowing into the temperature control oil circuit 8 is lower in temperature than the hot oil about to flow into the mold roller group 1. After heat exchange, the temperature of the hot oil about to flow into the mold roller group 1 will be reduced, thereby increasing the cooling gradient of the mold roller group 1 in the cooling section 1d, thereby making the temperature conditions of the system consistent with the temperature conditions required for foam processing.

[0088] like Figure 8 As shown, in the slow cooling mode: the cooling regulating valve 9 is opened to the fully open state, and the oil unloading valve 10a is closed; part of the hot oil is allowed to flow directly into the temperature control oil circuit 8.

[0089] When the thickness of the foam material to be processed is relatively thick, in order to allow the foam material to complete sufficient foaming, the foam material should be processed in a fast or slow cooling mode; in the slow cooling mode, part of the hot oil is allowed to flow directly into the temperature control oil circuit 8, so that the hot oil in the temperature control oil circuit 8 and the hot oil in the third connecting oil circuit 7 produce heat exchange.

[0090] Compared with the hot oil flowing out of the mold roller group 1, the hot oil flowing into the temperature control oil circuit 8 has a relatively higher temperature because it does not pass through the mold roller group 1. After heat exchange, the hot oil flowing out of the mold roller group 1 will be reheated, thereby reducing the cooling gradient of the mold roller group 1 in the cooling section 1d, so that the temperature conditions of the system are consistent with the temperature conditions required for foam processing.

[0091] like Figure 7 As shown, preferably, in the rapid cooling mode, the temperature of each mold roller group 1 corresponding to the cooling section 1d is regulated by adjusting the opening of each temperature regulating valve 8d, so that the approximate temperature of each mold roller group 1 is the same as the set temperature set manually; the specific calculation method of the approximate temperature of each mold roller group 1 is:

[0092] Troller=Tin-Uc·(1-fl)·(1-ft)·(Tin-Tsin);

[0093] in:

[0094] Troller is the approximate temperature of the die roller set 1;

[0095] Tin is the temperature of the hot oil flowing into the heat exchanger 8b in the third connecting oil passage 7;

[0096] Uc is the heat exchange efficiency of the heat exchanger 8b in counterflow (counterflow i.e. the direction of oil flow in the rapid cooling mode);

[0097] fl is the opening ratio of the cooling regulating valve 9, 0 is fully closed, and 1 is fully open;

[0098] ft is the opening ratio of the thermostatic control valve 8d, 0 is fully closed and 1 is fully open;

[0099] Tsin is the temperature of the relatively low temperature heating oil flowing into the heat exchanger 8b.

[0100] The specific calculation principle is as follows:

[0101] Because the mold roller set 1 is heated by hot oil, the temperature of the mold roller set 1 can be close to the temperature of the hot oil flowing in, that is, the temperature of the hot oil flowing out of the heat exchanger 8b in the third connecting oil path 7;

[0102] The temperature Tout of the hot oil flowing out of the heat exchanger 8b in the third connecting oil passage 7 can be expressed by the formula

[0103] Tout=Tin-Uc·Msin / Min·(Tin-Tsin);

[0104] Find, where:

[0105] Tout is the temperature of the hot oil flowing out of the heat exchanger 8b in the third connecting oil passage 7, that is, the temperature of the hot oil flowing into the mold roller;

[0106] Tin is the temperature of the hot oil flowing into the heat exchanger 8b;

[0107] Uc is the heat exchange efficiency of heat exchanger 8b in countercurrent flow;

[0108] Msin is the mass of the heating oil with a lower temperature flowing into the heat exchanger 8b in the temperature control oil circuit 8;

[0109] Min is the mass of the hot oil flowing into the heat exchanger 8b in the third connecting oil passage 7;

[0110] Tsin is the temperature of the relatively low-temperature heating oil flowing into the heat exchanger 8 b in the temperature control oil passage 8 .

[0111] Because Msin is related to the opening of the cooling control valve 9 and the temperature control valve 8d, its calculation formula is:

[0112] Msin=Min(1-fl)·(1-ft);

[0113] fl is the opening ratio of the cooling regulating valve 9, 0 is fully closed, and 1 is fully open;

[0114] ft is the opening ratio of the thermostatic control valve 8d, 0 is fully closed and 1 is fully open;

[0115] The calculation method of the opening ratio is:

[0116] f = amount of oil flowing out of the regulating valve / total amount of oil in the oil circuit;

[0117] Substituting the formula Msin=Min(1-fl)·(1-ft) into the equation, we get:

[0118] Tout=Tin-Uc·(1-fl)·(1-ft)·(Tin-Tsin);

[0119] By adjusting the opening ratio of the valve, the temperature of the mold roller group 1 is accurately controlled, thereby achieving rapid cooling at a low temperature, which is suitable for process requirements that require rapid cooling. The counterflow efficiency Uc of the heat exchanger 8b is used to ensure that the hot oil and the low-temperature oil are heat exchanged in the optimal state, fully utilizing the cooling capacity of the low-temperature oil and saving energy.

[0120] like Figure 8 As shown, preferably, in the slow cooling mode, there is a method for regulating the approximate temperature of each mold roller group 1 in the cooling section 1d: the temperature of each corresponding mold roller group 1 in the cooling section 1d is regulated by regulating the opening of each temperature regulating valve 8d, so that the approximate temperature of each mold roller group 1 is the same as the set temperature; the specific calculation method of the approximate temperature of each mold roller group 1 is:

[0121] Troller=Tin+Uf·(1-fl)·[fk / (1-fk)]·(Twar-Tin);

[0122] in:

[0123] Troller is the approximate temperature of die roller set 1;

[0124] Tin is the temperature of the hot oil flowing into the heat exchanger 8b in the third connecting oil passage 7;

[0125] Uf is the heat exchange efficiency of heat exchanger 8b in downstream flow;

[0126] fk is the opening ratio of the temperature control valve 8a, 0 is fully closed, 1 is fully open;

[0127] fl is the opening ratio of the thermostatic control valve 8d, 0 is fully closed and 1 is fully open;

[0128] Twar is the temperature of the hot oil in the temperature control oil passage 8 that does not flow through the mold roller set 1 .

[0129] The specific calculation principle is as follows:

[0130] Because the mold roller set 1 is heated by hot oil, the temperature of the mold roller set 1 can be close to the temperature of the hot oil flowing in; that is, the temperature of the hot oil flowing out of the heat exchanger 8b in the third connecting oil path 7;

[0131] The temperature of the hot oil flowing out of the heat exchanger 8b in the third connecting oil passage 7 can be expressed by the formula

[0132] Troller = Tin + Uf·Mwar / Min·(Twar-Tin) is calculated, where:

[0133] Tin is the temperature of the hot oil flowing into the heat exchanger 8b in the third connecting oil passage 7;

[0134] Uf is the heat exchange efficiency of the heat exchanger 8b in the downstream direction (downstream, i.e. the direction of oil flow in the slow cooling mode);

[0135] Mwar is the mass of hot oil in the temperature control oil circuit 8 that does not flow through the mold roller set 1;

[0136] Min is the mass of the hot oil flowing into the heat exchanger 8b in the third connecting oil passage 7;

[0137] Twar is the temperature of the hot oil in the temperature control oil circuit 8 that does not flow through the mold roller set 1.

[0138] Mwarm is the mass of hot oil in the temperature control oil circuit 8 that does not flow through the mold roller group 1 and flows into the heat exchanger 8b. Because Mwarm is related to the opening of the temperature control regulating valve 8a and the temperature regulating regulating valve 8d, its calculation formula is:

[0139] Mwarm=Min(1-fl)·[fk / (1-fk)];

[0140] fk is the opening ratio of the temperature control valve 8a, 0 is fully closed, and 1 is fully open;

[0141] fl is the opening ratio of the thermostatic control valve 8d, 0 is fully closed and 1 is fully open;

[0142] The calculation method of the opening ratio fk of the temperature control valve 8a is:

[0143] fk = oil volume flowing into temperature control oil circuit 8 / total oil volume at the merging point;

[0144] Substituting the formula Mwarm=Min(1-fl)·[fk / (1-fk)] into the equation, we get:

[0145] Troller=Tin+Uf·(1-fl)·[fk / (1-fk)]·(Twar-Tin);

[0146] In this step, by adjusting the opening of the temperature regulating valve 8d, the high-temperature hot oil can be slowly introduced into the heat exchanger 8b, thereby achieving gentle and gradual cooling, which is suitable for the process requirements of slow cooling. The temperature of each mold roller group 1 can be accurately adjusted, thereby improving the reliability and application range of the system.

[0147] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A mold heating control system, characterized in that: include: A plurality of mold roller groups (1) are distributed along the traveling direction of the foam material; each of the mold roller groups (1) comprises two rollers arranged one above the other, an oil channel is arranged inside the rollers, and the foam material passes through the two rollers; The plurality of mold roller groups (1) are divided into groups, and are sequentially divided into a preheating section (1a), a heating section (1b), a heat preservation section (1c) and a cooling section (1d) according to the advancing direction of the foam material; A mold oil passage (2) for introducing hot oil into the mold roller set (1) of the heating section (1b); A first connecting oil path (3) allows the oil flowing out of the heating section (1b) to flow into the mold roller group (1) of the preheating section (1a) in sequence along a direction opposite to the forward direction of the foam material; A second connecting oil circuit (4) allows the oil flowing out of the heating section (1b) to flow into the mold roller group (1) of the heat preservation section (1c) in sequence along the advancing direction of the foam material; The oil flowing out of the first connecting oil passage (3) and the oil flowing out of the second connecting oil passage (4) are merged at a merging point; An oil return line (6), used for returning oil; The third connecting oil circuit (7) allows the oil flowing out from the merging point to flow into the mold roller group (1) of the cooling section (1d) in sequence along the advancing direction of the foam material, and finally flow into the oil return circuit (6); the third connecting oil circuit (7) is provided with a heating regulating valve (7a) between the merging point and the cooling section (1d); a temperature control oil circuit (8), the two ends of which are respectively connected to the merging point and the outlet of the third connecting oil circuit (7); the temperature control oil circuit (8) is provided with a temperature control regulating valve (8a) and a plurality of heat exchangers (8b), the temperature control regulating valve (8a) being arranged at the inlet of the temperature control oil circuit (8); the heat exchanger (8b) being arranged in the middle section of the temperature control oil circuit (8) for exchanging heat with the third connecting oil circuit (7); A temperature-lowering regulating valve (9) is arranged between the temperature-control oil circuit (8) and the oil return oil circuit (6); The oil unloading circuit (10) is connected to the temperature control circuit (8) and the oil return circuit (6), and the connection point with the temperature control circuit (8) is located between the temperature control regulating valve (8a) and the heat exchanger (8b); the oil unloading circuit (10) is provided with an oil unloading valve (10a).

2. The heating control system according to claim 1, characterized in that: The merging point is provided with a mixer (5) for mixing the hot oil flowing out of the first connecting oil passage (3) and the second connecting oil passage (4).

3. The heating control system according to claim 1, characterized in that: The temperature control oil circuit (8) includes an oil guide oil circuit (8c) arranged in parallel with the heat exchanger (8b), and a temperature regulating valve (8d) is arranged on the oil guide oil circuit (8c).

4. The heating control system according to claim 1, characterized in that: A radiator (8e) is also provided on the temperature control oil circuit (8), and the radiator (8e) is between the heat exchanger (8b) and the outlet of the third connecting oil circuit (7).

5. The heating control system according to claim 1, characterized in that: An oil pump (6a) is installed in the oil return line (6).

6. The heating control system according to claim 1, characterized in that: Each of the oil inlet and oil outlet of the mold roller group (1) is provided with a heating temperature sensor (11).

7. The heating control system according to claim 1, characterized in that: Each inlet and outlet of each heat exchanger (8b) is provided with a temperature control temperature sensor (12).

8. A mold heating control method, characterized in that: A mold heating control system for use as claimed in any one of claims 1 to 7, comprising: Normal mode: adjust the heating regulating valve (7a) and the temperature control regulating valve (8a) so that the hot oil in the oil circuit flows evenly into the third connecting oil circuit (7) and the temperature control oil circuit (8), open the oil discharge valve (10a), adjust the temperature reduction regulating valve (9) to a fully open state, and introduce the hot oil into all the mold roller groups (1) until the temperature of all the mold roller groups (1) is stable; Rapid cooling mode: reducing the flow rate of the cooling regulating valve (9) so that the flow rate of the cooling regulating valve (9) is smaller than that of the heating regulating valve (7a), so that the heating oil with lower temperature in each part flows into the temperature control passage; Slow cooling mode: open the cooling regulating valve (9) to the fully open state and close the oil unloading valve (10a); so that part of the hot oil flows directly into the temperature control passage.

9. The mold heating control method according to claim 8, characterized in that: In the rapid cooling mode, the temperature of each corresponding mold roller group (1) in the cooling section (1d) is also regulated by adjusting the opening of each temperature regulating valve (8d), so that the approximate temperature of each mold roller group (1) is the same as the set temperature; the specific calculation method of the approximate temperature of each mold roller group (1) is: Troller=Tin-Uc•(1-fl)•(1-ft)•(Tin-Tsin); in: Troller is the approximate temperature of the die roller set (1); Tin is the temperature of the hot oil flowing into the heat exchanger (8b) in the third connecting oil path (7); Uc is the heat exchange efficiency of the heat exchanger (8b) in countercurrent flow; fl is the opening ratio of the cooling control valve (9), 0 is fully closed, and 1 is fully open; ft is the opening ratio of the thermostatic control valve (8d), 0 is fully closed and 1 is fully open; Tsin is the temperature of the relatively low-temperature heating oil flowing into the heat exchanger (8b) in the temperature control oil circuit (8).

10. The mold heating control method according to claim 8, characterized in that: In the slow cooling mode, the temperature of each corresponding mold roller group (1) in the cooling section (1d) is also regulated by adjusting the opening of each temperature regulating valve (8d), so that the approximate temperature of each mold roller group (1) is the same as the set temperature; the specific calculation method of the approximate temperature of each mold roller group (1) is: Troller=Tin+Uf•(1-fl)•[fk / (1-fk)]•(Twar-Tin); in: Troller is the approximate temperature of the die roller set (1); Tin is the temperature of the hot oil flowing into the heat exchanger (8b) in the third connecting oil path (7); Uf is the heat exchange efficiency of the heat exchanger (8b) in the downstream direction; fk is the opening ratio of the temperature control valve (8a), 0 is fully closed, and 1 is fully open; fl is the opening ratio of the thermostatic regulating valve (8d), 0 is fully closed and 1 is fully open; Twar is the temperature of the hot oil in the temperature control oil circuit (8) that does not flow through the mold roller group (1).

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