Operating method of an indirect pressurized steam recompression type heat pump treatment device

Abstract

To develope a method of operating a novel indirectly pressurized vapor recompression heat-pump type processing device equipped with a pair of compressors connected in two stages, capable of remarkably enhancing the efficiency of the whole device by maintaining a heat exchanger recovering heat from carrier gas discharged from a dryer with the drain of the heat medium, in a good heat exchanging condition.SOLUTION: The method of operating a novel indirectly pressurized vapor recompression heat-pump type processing device that controls the rotation rate of a first stage compressor 5A to control the amount of a vaporized heat medium in a heat exchanger 45 so that the primary pressure of the first stage compressor 5A reaches a predetermined value, is characterized by performing fuzzy inference with the antecedents being [the ratio of regenerated steam], [the speed of the second stage compressor], [the speed of the first stage compressor], and [the suction pressure of the first stage compressor], and the consequent being [the operation amount of the set value of the suction pressure of the first stage compressor].SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a method and apparatus for drying and concentrating materials such as mud, cake, powder, granular materials, and liquid materials. In particular, in a conduction heat dryer, heat of a carrier gas containing water vapor evaporated from a workpiece and discharged from an exhaust port is used to re-evaporate a heat medium that has decreased in temperature and is discharged from a heating device in a drain state, and the heat medium is circulated and used as a drying heat source for the workpiece. Operating method of an indirect pressurized steam recompression type heat pump treatment device It relates to the above.

Background Art

[0002] Recently, efforts for environmental conservation have been actively carried out. For companies and the like, general waste such as food waste and food processing residues, and sewage sludge are dried to reduce the amount and prevent spoilage, and then recycled or disposed of. One of the devices used for such drying is a heat pump type processing device that uses the steam generated from the workpiece itself as a heating source for the workpiece. This device is called a direct pressure type (steam recompression type).

[0003] On the other hand, many indirect pressure type heat pump type processing devices apply a refrigeration system using a refrigerant such as Freon as a heat medium, and it is necessary to operate a series of systems from a dryer to a vacuum exhaust device under vacuum. The dryer becomes a vacuum dryer, and a robust main body that can withstand external pressure and a special system for discharging the dried product are required. Therefore, conventionally, there has been no example of putting a conduction heat dryer with an indirect pressure type steam recompression type heat pump into practical use.

[0004] Therefore, the applicant has developed a novel steam recompression type heat pump type processing device that can configure the entire device on a small scale, can continuously perform the drying and concentration operations of the workpiece, can further reduce power consumption, and can further prevent the contamination of condensed water, and has already filed a patent application. This invention has been evaluated and registered (see Patent Document 1).

[0005] Furthermore, the applicant has been conducting research and development on a steam recompression type heat pump treatment apparatus and has attempted various improvements. Based on the idea of ​​using superheated steam instead of outside air as the carrier gas, which has been the conventional practice in this field, the applicant has devised an invention that can continuously dry the material to be treated under atmospheric pressure and significantly reduce the manufacturing cost of the apparatus. This invention has already been filed as a patent application and has been evaluated and registered (see Patent Document 2).

[0006] Furthermore, the applicant has developed a device that can resolve the aforementioned problems such as compressor failure by applying the above invention, which is characterized by the use of superheated steam as a carrier gas, to an indirect pressurized steam recompression type heat pump treatment device, which is different from a direct pressurized steam recompression type. This device has already been patented, and this invention has also been evaluated and registered (see Patent Document 3).

[0007] Since then, the applicant has continued research and development of such indirect pressurized steam recompression type heat pump treatment devices, and has come to recognize that there is room for improvement in the following areas. Firstly, in the case of a heating device where the heat transfer medium discharged from the heating device is in a condensate state, the re-evaporation of this condensate becomes insufficient. Secondly, the suction side of the compressor becomes a negative pressure, which is lower than atmospheric pressure, causing a decrease in efficiency. Furthermore, in this case, the discharge pressure of the compressor decreases, reducing the overall efficiency of the device.

[0008] To solve these problems, the applicant has developed a novel drying and concentration method and apparatus that uses a two-stage compressor configuration, with the first-stage compressor used exclusively for reducing pressure on its upstream side (suction side) to improve the evaporation of the condensate-state heat transfer medium, while simultaneously creating positive pressure on its downstream side (discharge side). This avoids a decrease in the efficiency of the second-stage compressor and significantly improves the overall efficiency of the apparatus. This invention has already been filed for patent application and has been evaluated and registered (see Patent Document 4 and Figure 8 of this case).

[0009] Subsequently, as the practical application and operation of heat pump type processing equipment equipped with the continuous conduction heat transfer dryer disclosed in Patent Document 4 progressed, it became apparent that there was room for improvement in the following areas. Specifically, as shown in Figure 8, the carrier gas S is exhausted from the exhaust port 104'. 5 Therefore, the amount of heat recovered in the heat transfer medium drain D0 (saturated steam S1) varies depending on factors such as the type, condition, and input amount of the material being processed, and may exceed the amount of heat required by the dryer 1'.

[0010] Therefore, currently, one The primary pressure of the second stage compressor 5A' is set to a predetermined value (approximately 20-40 kPaG lower than atmospheric pressure). one The rotational speed of the second stage compressor 5A' is controlled by PID control to control the amount of evaporation of the heat transfer medium in the heat exchanger 45', and the following control is also performed. First, if the amount of heat recovered in the heat exchanger 45' exceeds the processing capacity of the second-stage compressor 5B', the pressure between the first-stage compressor 5A' and the second-stage compressor 5B' will rise. Therefore, a venting mechanism (discharge valve 47') is provided to discharge excess saturated steam S2 to the outside of the system, and control is performed to release a portion of the saturated steam S2 to the outside and reduce the amount of saturated steam S2 drawn in by the second-stage compressor 5B'. Also, if the amount of heat required by dryer 1' decreases, two Since there is excess thermal energy from the saturated steam S3 discharged from the compressor 5B' in the first stage, a small amount of outside air S10 is added to the carrier gas in the heat exchanger 45' to reduce the amount of heat recovered into the heat transfer medium, drain D0 (saturated steam S1).

[0011] However, these operations, when viewed as a whole system, are contrary to energy conservation. Therefore, from an energy conservation standpoint, it is preferable to minimize the amount of outside air introduced into the carrier gas S5 in the heat exchanger 45' and the amount of saturated steam S2 released to the outside between the first-stage compressor 5A' and the second-stage compressor 5B'. And the method for that is the drain D in the exchanger 45' 0 It is possible to adjust the amount of heat recovered into (saturated steam S1) as appropriate, one The second stage compressor 5A' is PID controlled so that the primary pressure reaches a predetermined value. It is extremely difficult for the operator to manually change the predetermined primary pressure by knowing the surplus amount of saturated steam S2 and the amount of heat required by the dryer 1', and even if it were possible, it would place a tremendous burden on the operator. [Prior art documents] [Patent Documents]

[0012] [Patent Document 1] Japanese Patent Publication No. 2005-331210 (Japanese Patent No. 4420737) [Patent Document 2] Japanese Patent Publication No. 2014-6017 (Patent No. 6008609) [Patent Document 3] Japanese Patent Publication No. 2014-70886 (Patent No. 6063196) [Patent Document 4] Japanese Patent Publication No. 2015-81712 (Patent No. 6291211) [Overview of the Initiative] [Problems that the invention aims to solve]

[0013] The present invention was made against this background, and the technical challenge was to develop a novel operating method for an indirect pressurized steam recompression type heat pump treatment apparatus equipped with a two-stage compressor, which can significantly improve the overall efficiency of the apparatus by improving the state of heat exchange in the heat exchanger that recovers heat from the carrier gas discharged from the dryer to a heat transfer medium in a drain state. [Means for solving the problem]

[0014] That is, the claim described in claim 1 、The operation method of an indirectly pressurized steam recompression type heat pump type processing apparatus is as follows. A heat pump type processing apparatus provided with a continuous conduction heat dryer configured such that a heating device is provided in a main body shell and an object to be processed is brought into contact with a heat transfer surface of the heating device to evaporate moisture. Driving The method is such that the heat pump type processing apparatus re-evaporates a heat medium discharged from the heating device in a drain state due to a temperature decrease, and then uses a compressor to increase the pressure and temperature Let and then supplies it to the heating device again for circulation use. 、 Furthermore, the heating device dries the workpiece by exchanging heat with a heat transfer medium. It is configured as such. The heat of a carrier gas containing water vapor evaporated from the object to be processed, which is discharged from an exhaust port formed in the main body shell, is taken into the heat medium in the drain state in a heat exchanger to be re-evaporated. Moreover, the compressor is provided with two compressors in series. First, the first-stage compressor performs decompression on the upstream side of the first-stage compressor and sets the pressure on the suction side of the second-stage compressor to a positive pressure so as to promote the re-evaporation of the heat medium in the drain state. Subsequently, the second-stage compressor performs pressurization so that the temperature of the heat medium reaches a desired value. In the operation method of an indirectly pressurized steam recompression type heat pump type processing apparatus, the rotation speed of the first-stage compressor is controlled so that the pressure on the primary side of the first-stage compressor becomes a predetermined value, and the evaporation amount of the heat medium in the heat exchanger is controlled. The condition part is set as "recycled steam ratio", "second-stage compressor speed", "first-stage compressor speed", and "first-stage compressor suction pressure", and it is characterized by performing fuzzy inference with the conclusion part being the "operation amount of the suction pressure setting value of the first-stage compressor".

[0015] Also, in the operation method of the indirectly pressurized steam recompression type heat pump type processing apparatus according to claim 2, in addition to the above requirements, 、 the method is Between the first-stage compressor and the second-stage compressor, a mechanism for discharging the heat medium to the outside is provided. When the pressure of the heating medium between the first-stage compressor and the second-stage compressor exceeds a predetermined value, a part of the heat medium is discharged to the outside.

[0016] Furthermore, according to the third aspect 、 The operation method of the indirect pressurization type steam recompression type heat pump type treatment device, in addition to the above requirements, The outside air can be introduced into the carrier gas supplied to the heat exchanger, two When the heat energy of the heat medium discharged from the compressor of the [X]th stage becomes surplus, By introducing the outside air into the carrier gas supplied to the heat exchanger, the heat recovery to the heat medium is reduced. And by using the configurations of the inventions described in these claims as means, the above problems can be solved.

Advantages of the Invention

[0017] First, according to the invention described in claim 1, the pressure on the primary side of the first-stage compressor is changed to an appropriate setting, and the heat recovery from the saturated steam (carrier gas) is carried out without excess or deficiency to control the generation amount of the saturated steam, and a saturated steam having the required amount of heat required by the dryer can be obtained, and the operation of the drying and concentration device becomes possible. As a result, the operation of the compressor can be optimized according to the operation status of the drying and concentration device, so that the operation with reduced power consumption becomes possible. In addition, since the operation that maximally utilizes the heat pump cycle becomes possible, the required amount of auxiliary steam can be reduced, and the energy consumption of the steam generation device can be reduced. Furthermore, since the above-described complex control is performed by fuzzy control, the burden on the operator can be significantly reduced.

[0018] Furthermore, according to the invention described in claim 2, even when saturated steam is released outside the system, energy loss can be reduced by suppressing the release of saturated steam outside the system.

[0019] Furthermore, according to the invention described in claim 3, even when outside air is introduced into the heat exchanger, the introduction of outside air into the heat exchanger is suppressed, thereby reducing the load on the deodorization equipment. [Brief explanation of the drawing]

[0020] [Figure 1] This is a block diagram showing a drying and concentration apparatus (indirect pressurized steam recompression type heat pump treatment apparatus) to which the present invention is applied. [Figure 2] This is a side view showing a partially cut-out section of the dryer. [Figure 3] These are front and rear views showing a partially transparent view of the dryer. [Figure 4] This is a cross-sectional view showing the compressor. [Figure 5] This is a graph showing the membership function of the conditional part (antecedent part) of fuzzy inference. [Figure 6] This is a graph showing the conclusion (consequence) of a fuzzy inference. [Figure 7-1] This is a table showing the rules of fuzzy inference. [Figure 7-2] This is a table showing the rules of fuzzy inference. [Figure 7-3] This is a table showing the rules of fuzzy inference. [Figure 7-4] This is a table showing the rules of fuzzy inference. [Figure 8] This is a block diagram of an existing drying and concentration apparatus. [Modes for carrying out the invention]

[0021] The best mode of operation for the indirect pressurized steam recompression type heat pump treatment apparatus of the present invention is shown in the following embodiment, but it is possible to make appropriate modifications to this embodiment within the scope of the technical idea of ​​the present invention. [Examples]

[0022] As an example, the indirect pressurized steam recompression type heat pump treatment apparatus H to which the present invention is applied consists mainly of a dryer 1, an input device 2, a circulation path 4, and a header 3 and a compressor 5 provided in the circulation path 4, as shown in Figure 1. In this context, the indirect pressurized steam recompression type is configured to re-evaporate the heat transfer medium supplied to the heating device in the dryer 1, which is then discharged as condensate after its temperature drops, and then pressurized and heated using a compressor before being supplied back to the heating device for reuse. On the other hand, the direct pressurized steam recompression type is configured to pressurize and heat the exhaust gas containing moisture released from the material to be processed in the dryer 1 using a compressor, and then supply it to the heating device as a heating medium. The condensed heating medium is then discharged to the outside as condensate and is not reused.

[0023] The components of the indirect pressurized steam recompression type heat pump treatment apparatus H will be described in detail below, followed by a description of the operating method of the present invention for drying and concentrating the material to be treated using this apparatus. First, let me explain the dryer 1. As shown in Figures 2 and 3, this dryer employs a so-called conductive heat transfer type of equipment. It consists of a main shell 10, which is a processing chamber, mounted on a machine frame F, and a multi-tube heating device 11, which is an example of a heating device mounted inside and functions as a condenser in this embodiment. Then, the multi-tube heating tube 11 is rotated while saturated steam S4, which is a heat transfer medium, is flowed through it, and the object to be processed is brought into contact with the outer surface (heat transfer surface) of the multi-tube heating tube 11, thereby conducting the heat of the saturated steam S4 to the object to be processed and drying it.

[0024] As shown in Figure 3, the main body shell 10 in this embodiment is a hollow member having an elliptical cross-section, and has an inlet 101, an outlet 102, a carrier gas outlet 103, and an exhaust port 104. The inlet 101 is formed near the end of the main body shell 10, and the exhaust port 104 is formed near this inlet 101. Furthermore, a second inlet 101 is formed in the main body shell 10 closer to the center than the exhaust port 104, so in this embodiment, the inlet 101 is formed in two places, flanking the exhaust port 104. Of course, it is also possible to form inlet 101 at multiple locations along the longitudinal direction of the multi-tube heating tube 11, which will be described later. In this embodiment, a rotary valve 105 is provided at the discharge port 109 formed below the outlet 102, but a double damper type discharge device or the like may also be provided. Furthermore, the main body shell 10 and the multi-tube heating tubes 11 are installed on the machine frame F either horizontally or at an angle such that the input port 101 side is slightly higher than the outlet port 102 side.

[0025] Furthermore, the main body shell 10 has a double-jacket structure, and although not shown in Figure 1, as shown in Figure 2, a passage for the heating medium is formed from the steam supply port 106 to the drain port 107, allowing the temperature inside the main body shell 10 to rise. Alternatively, a trace pipe can be installed instead of this double-jacket structure.

[0026] Furthermore, the main body shell 10 is designed for use under normal pressure, and therefore does not require strict airtightness, nor does it require complex input / discharge mechanisms or supply / exhaust mechanisms. As a result, the dryer 1 and the indirect pressurized steam recompression type heat pump treatment device H can be constructed at low cost. Incidentally, in the drying and concentration apparatus disclosed in Patent Document 1, saturated steam at 100-120°C (101-199 kPa-abs) is supplied to a multi-tube heating system. Therefore, in order to promote the evaporation of moisture from the material being processed, it is necessary to lower the boiling point. For this reason, the apparatus is operated under a vacuum inside the main shell, and the main shell is required to maintain strict airtightness.

[0027] Furthermore, the multi-tube heating tube 11 is made up of a cylindrical tube bundle 116 with end plates 112 on both sides and a shaft 113 at the center of the end plates 112, with the shaft 113 rotatably supported by a bearing block 114 provided on the machine frame F. A motor M is provided on the machine frame F as a power source for rotating the multi-tube heating tube 11. Rotary joints 115a and 115b are attached to both ends of the shaft 113 and connected to the tube bundle 116. A sealing mechanism is also provided between the shaft 113 and the main body shell 10 to prevent contact with the outside air. Furthermore, the side circumference of the tube bundle 116 is equipped with numerous angles 111 (12 in this embodiment) to which multiple lifters 117 and feed vanes 118 with appropriate angles are attached. These allow the material to be processed to be lifted up and brought into contact with the tube bundle 116, and to move from the inlet 101 side to the outlet 102 side. Furthermore, a temperature sensor 74 is provided inside the end plate 112 on the outlet 102 side (more specifically, only the sensing tip of the temperature sensor 74 is inserted into the end plate 112), making it possible to measure the temperature of the multi-tube heating tube 11. This temperature sensor 74, together with the drain discharge pipe (not shown) described later, passes through the rotary joint 115b and through the inside of the shaft 113, and is positioned inside the end plate 112 on the outlet 102 side.

[0028] Next, the input device 2 will be described, and as an example, a Mono pump (registered trademark) equipped with a hopper 20 is used, and its discharge port is connected to the input port 101 of the dryer 1 by an appropriate route. In the drying and concentration apparatus disclosed in Patent Document 1, the hopper is designed to allow vacuum degassing, preventing air from entering the main shell of the dryer. However, as mentioned above, such a structure is not necessary in the indirect pressurized steam recompression type heat pump treatment apparatus H of the present invention. Although not shown in the diagram, carrier gas (saturated steam S5) is discharged from the exhaust port 104 of the main body shell 10, and since this is a so-called dry exhaust gas, it is preferable to provide various bag filters or a cyclone-type dust collector between it and the heat exchanger 45, which will be described later.

[0029] Next, the circulation path 4 will be described. As shown by the thick line in Figure 1, this path is a closed passage formed outside the dryer 1 that connects the rotary joint 115a and rotary joint 115b in the multi-tube heating tube 11 with a pipeline, and is equipped with multiple pieces of equipment along its course. Specifically, from the side closest to the rotary joint 115b, it is equipped with a drain tank 41, a pump P, a heat exchanger 45, a compressor 5, and a header 3. With this configuration, saturated steam S1, which serves as a heat transfer medium located in the circulation path 4, is pressurized and heated by the compressor 5, and auxiliary steam S0 is supplied as needed by the header 3. This steam is then supplied to the multi-tube heating tube 11 as saturated steam S4. Furthermore, the drain D0 discharged from the multi-tube heating tube 11 and then from the drain tank 41 is re-evaporated in the heat exchanger 45 to become saturated steam S1, which is then pressurized and heated again by the compressor 5, making it possible to circulate and reuse the steam. Furthermore, a pipeline equipped with a drain discharge valve 49 is connected to the drain tank 41, and by connecting this pipeline to the jacket of the input device 2, the heat of the drain D0 discharged from the drain tank 41 can be used as a heat source for these devices.

[0030] In this embodiment, the heat exchanger 45 is a so-called shell-and-tube type, in which multiple conduits are arranged inside the housing and heat exchange takes place between the fluid flowing inside the conduits and the fluid flowing outside. However, various other types, such as so-called full-liquid heat exchangers, can also be used.

[0031] Furthermore, the compressor 5 is configured with a first-stage compressor 5A, which is used exclusively for reducing the pressure in the space outside the heat transfer tubes where drain D0 exists in the heat exchanger 45, and a second-stage compressor 5B, which is used for increasing pressure and temperature, both of which are provided in series in the circulation path 4. First, the first stage compressor 5A is, for example, a Roots-type compressor. a Therefore, a system is adopted that can set the pressure on the suction side (primary side) to approximately -0.02 to -0.04 MPaG and the pressure on the discharge side (secondary side) to approximately 0.00 to 0.6 MPaG. Furthermore, the second-stage compressor 5B may, for example, be a screw-type steam compressor, which is a device that has low power consumption while having a high compression ratio. In this embodiment, as an example of compressor 5B, a device is adopted that can set the pressure on the discharge side (secondary side) to 0.1 to 0.8 MPaG when the pressure on the suction side (primary side) is 0.00 to 0.10 MPaG.

[0032] By adopting this configuration, the temperature difference between the saturated steam S3 (for example, 158.8°C (0.5 MPaG)) and the temperature of the material to be processed can be made large, thereby increasing the drying efficiency and making it possible to miniaturize the dryer 1. Furthermore, because the compressor 5A creates a negative pressure on the suction side, the saturation temperature at, for example, -0.025 MPaG becomes 92.2°C, allowing the heat exchanger 45 to recover a large portion of the latent heat of vapor from the carrier gas S5 containing water vapor evaporated from the material being processed. Furthermore, in compressor 5B, the suction pressure is made positive by compressor 5A, thus preventing a decrease in efficiency.

[0033] Furthermore, a pressure sensor 43 is provided in front of the compressor 5A in the circulation path 4. Based on the value detected by this pressure sensor 43, the rotational speed of the compressor 5A is controlled by PID control so that the primary pressure of the compressor 5A can be set to a predetermined value (a value approximately 20 to 40 kPaG lower than atmospheric pressure). Furthermore, a pressure sensor 46 is provided between compressor 5A and compressor 5B, and based on the value detected by this pressure sensor 46, a discharge valve 47 provided in the pipeline branched from the circulation path 4 is controlled to release a portion of the saturated steam S2 to the outside. Furthermore, a steam flow meter 44 is provided downstream of the compressor 5B, and based on the detected value of this steam flow meter 44, the pipeline connected to the supply section of the carrier gas (saturated steam S5) in the heat exchanger 45 is configured re The system is configured to allow outside air to be introduced by controlling the introduction valve 48.

[0034] Here, the Roots compressor, referred to as the compressor 5A, is configured as shown in Figure 4(a), with a pair of rotors 53 meshed together in a rotor chamber 52a formed in a casing 52. Saturated steam S1 that flows into the rotor chamber 52a from the air intake port 55 is compressed by the rotors 53 and discharged from the exhaust port 56 as pressurized and heated saturated steam S2. Furthermore, a water inlet 57 is formed in a connected state in the rotor chamber 52a, and by supplying cooling water into the rotor chamber 52a from this water inlet 57, it is possible to control the degree of superheating of the saturated steam S1 compressed in the rotor chamber 52a. Although Figure 4(a) shows a three-lobed rotor 53, a two-lobed rotor may also be used. Furthermore, by employing a Roots-type compressor as compressor 5A, the suction action of this compressor 5A allows for a sufficient margin to achieve the desired low pressure on the suction side. Furthermore, the compressor 5A can be a multi-stage Roots compressor, a multi-stage turbo blower, or any other type of compressor capable of achieving the aforementioned compression capacity.

[0035] Next, the screw-type steam compressor 5B will be described. As shown in Figure 4(b), this compressor has a pair of screws 54 meshed together in a screw chamber 52b formed in a casing 52. Saturated steam S2 that flows into the screw chamber 52b from the air intake port 55 is compressed by the screws 54 and discharged from the exhaust port 56 as pressurized and heated saturated steam S3. Furthermore, a water inlet 57 is formed in a connected state in the screw chamber 52b, and by supplying cooling water into the screw chamber 52b from this water inlet 57, it is possible to control the degree of superheating of the saturated steam S2 compressed in the screw chamber 52b. Furthermore, the compressor 5B can be a multi-stage Roots compressor, a multi-stage turbo blower, or any other type of compressor capable of achieving the aforementioned compression capacity.

[0036] Furthermore, a steam generator 30 is connected to the header 3, and the auxiliary steam S0 supplied from the steam generator 30 is mixed with saturated steam S3 in the header 3 and supplied as saturated steam S4 to the rotary joint 115a in the dryer 1. Additionally, a portion of the saturated steam S4 is supplied to the carrier gas inlet 103 through a pipeline branched off from the circulation path 4.

[0037] Furthermore, the main body shell 10 is designed for use under normal pressure conditions, but normal pressure here generally refers to atmospheric pressure (1 atmosphere), which can vary depending on weather and geographical conditions. Furthermore, if the pressure inside the main shell 10 is in the range of -0.02 to +0.1 kPaG relative to atmospheric pressure, it is possible to prevent the intake of outside air or the leakage of the internal atmosphere (saturated vapor S4 as a carrier gas) to the outside air using a general and simple sealing material or sealing mechanism. In this specification, "normal pressure" includes the range of -0.02 to +0.1 kPaG relative to atmospheric pressure. Of course, by employing a sealing material or sealing mechanism that can further enhance airtightness, it becomes possible to tolerate a wider range of pressures in the internal atmosphere (saturated vapor S4 as a carrier gas) of the main body shell 10.

[0038] This invention related The indirect pressurized steam recompression type heat pump treatment apparatus H is configured as described above as an example, and the operating method of this apparatus, along with the operating method of the present invention, will be described below.

[0039] (1) Preparing the dryer First, prior to loading the material to be processed, the multi-tube heating tube 11 and the main shell 10 of the dryer 1 are heated. After supplying heating steam from the steam generator 30 to the rotary joint 115a and the steam supply port 106, the motor M is started to rotate the multi-tube heating tube 11. The heating steam supplied to the rotary joint 115a heats the multi-tube heating tube 11 as it passes through the tube bundle 116, and eventually becomes drain D0 which is discharged from the rotary joint 115b on the other end. The heating steam supplied to the steam supply port 106 heats the main shell 10, and eventually becomes drain which is discharged to the outside from the drain port 107. Furthermore, a siphon tube (not shown) is provided inside the end plate 112 on the rotary joint 115b side, and a steam trap (not shown) is provided in the path through which the drain discharged from the rotary joint 115b flows. In addition, a steam trap (not shown) is provided in the path through which the drain discharged from the drain port 107 flows. Furthermore, when preparing the dryer 1 as described above, the drain D0 generated in the multi-tube heating tube 11 is discharged from the circulation path 4 by opening the drain discharge valve 49. Similarly, non-condensable gases such as air that have entered the multi-tube heating tube 11 due to leakage are discharged from the circulation path 4 through the discharge valve 47, etc.

[0040] (2) Circulation of heat transfer medium Next, the compressor 5, namely compressors 5A and 5B, is started to increase the pressure and temperature of the saturated steam S1 located in the circulation path 4, and sends it to the header 3 as saturated steam S3. There, an appropriate amount of auxiliary steam S0 supplied from the steam generator 30 is mixed in, and the saturated steam S4 is supplied to the multi-tube heating tube 11. The heat transfer medium discharged from the multi-tube heating tube 11 as drain D0 is then sent to the heat exchanger 45 by the pump P. to The carrier gas (saturated steam S5) discharged from the exhaust port 104 is re-evaporated by the heat to become saturated steam S1. In this case, as will be described later, the pressure on the suction side (primary side) of compressor 5A is reduced by compressor 5A, so the saturation temperature is 90.6~94.0℃. As a result, the heat transfer efficiency from the carrier gas (saturated steam S5) to the heat transfer medium (drain D0) is improved, and re-evaporation occurs smoothly.

[0041] Next, saturated steam S1 is supplied to compressor 5A, where it is pressurized and heated by the action of rotor 53, and supplied to compressor 5B as saturated steam S2. The rotational speed of the compressor 5A is controlled by PID based on the value detected by the pressure sensor 43 and the primary side pressure setting value. The rotational speed is controlled so that the primary side pressure of the compressor 5A is a predetermined value, for example, -0.02 to -0.04 MPaG, or approximately 60 to 80 kPaA. Furthermore, the value detected by the pressure sensor 46 at this time, i.e., the pressure of the saturated steam S2, is set to 0.05 to 0.06 MPaG as an example. When the pressure of the saturated steam S2 rises above this level, the opening of the release valve 47 is adjusted to release a portion of the saturated steam S2 to the outside.

[0042] Next, the saturated steam S2 is pressurized and heated in the compressor 5B by the action of the screw 54, becoming saturated steam S3. The rotational speed of the screw 54 in the compressor 5B is controlled so that the pressure detected by the pressure sensor 46 of saturated steam S2 reaches a desired value. At this time, the pressure on the suction side of the compressor 5B is positive. pressure andThis makes it possible to avoid a decrease in the efficiency of compressor 5B.

[0043] Then, when the saturated steam S3 reaches the header 3, auxiliary steam S0 is supplied as needed according to the operational control request signal, and the saturated steam S4, which has been brought to the desired temperature, is supplied to the rotary joint 115a. The supply of auxiliary steam S0 to the saturated steam S3 in the header 3 is also done to replenish the amount of carrier gas (saturated steam S5) that is discharged to the outside of the main shell 10 and lost from the circulation path 4, as well as the amount of drain D0 that passes through the drain discharge valve 49, as will be described later. Subsequently, the saturated steam S4 passes through the shaft 113 and enters the end plate 112, and then passes through the tube bundle 116. In this process, as will be described later, the latent heat of the saturated steam S4 is transferred to the workpiece that is in contact with the outer surface of the multi-tube heating tube 11, thereby promoting the evaporation of moisture from the workpiece.

[0044] (3) Drying of the material to be treated Next, the material to be processed is fed from the feeding device 2 into the main shell 10 through the input port 101. This material is moved from the input port 101 side to the overflow port 102 side by the action of the feed vane 118, and is then scraped up by the lifter 117 and comes into contact with the tube bundle 116, etc., at which point it is heated and the moisture evaporates. In this case, since the input ports 101 are formed at multiple locations along the longitudinal direction of the multi-tube heating tube 11, the heat conduction surface of the multi-tube heating tube 11 can be effectively used, thereby increasing the drying efficiency. The water vapor evaporated from the material being processed is then quickly absorbed by the carrier gas (saturated steam S4). Furthermore, the material being processed is also heated by the carrier gas (saturated steam S4), which further promotes water evaporation. The processed material that reaches the discharge port 109 from the overflow port 102 is then discharged in a dried state and transferred to the next process.

[0045] (4) Exhaust of carrier gas On the other hand, the carrier gas (saturated steam S5) that takes in the water vapor evaporated from the material to be processed is exhausted to the outside of the main shell 10 through the exhaust port 104. This exhaust gas (saturated steam S5) is a so-called dry exhaust gas, which reaches the heat exchanger 45, where it undergoes heat exchange with the drain D0, is heated, and re-evaporated to obtain saturated steam S1. The exhaust gas (saturated steam S5) after heat exchange with the drain D0 is discharged to the outside via a condenser and deodorizing equipment.

[0046] (5) Utilization of drains In the drain tank 41, the amount of liquid inside the tank is detected by a water level gauge provided as appropriate. When the upper limit of the liquid level is detected, the drain valve 49 is opened, and the drain D0 is supplied to the jacket of the input device 2, etc., and used as a heat source for these devices.

[0047] (6) Introduction of outside air Furthermore, as mentioned above, if the amount of heat required by dryer 1 decreases while the indirect pressurized steam recompression type heat pump treatment device H continues to operate, two In some cases, the thermal energy of the saturated steam S3 discharged from the second stage compressor 5B becomes excess. Here, a surplus of thermal energy specifically refers to a state where the steam flow rate of saturated steam S3 is excessive, which is measured by the steam flow meter 44. When the amount of steam flowing exceeds the appropriate steam flow rate setting value set in the steam flow meter 44, the opening of the outside air inlet valve 48 is controlled by a signal corresponding to the deviation, and the carrier gas (saturated steam S3) in the heat exchanger 45 is controlled. 5 By introducing outside air to the supply section of the system, control is performed to reduce heat recovery into the heat transfer medium, drain D0 (saturated steam S1), and as a result, re-evaporation from drain D0 to saturated steam S1 is suppressed.

[0048] (7) Fuzzy control Furthermore, the present invention applies fuzzy control to the operation of the indirect pressurized steam recompression type heat pump treatment device H as described above. This optimizes the amount of saturated steam S2 released from the system, i.e., the amount of steam released from the circulation path 4 through the discharge valve 47, the amount of outside air introduced into the heat exchanger 45, and the proportion of regenerated steam, as described later. As a result, even if there are fluctuations in the evaporated moisture from the material being treated, the energy efficiency of the indirect pressurized steam recompression type heat pump treatment device H is optimized. Specifically, the "regeneration steam ratio," "second-stage compressor speed," "first-stage compressor speed," and "first-stage compressor suction pressure" are used as the conditional part (antecedent), and the "operated value of the first-stage compressor suction pressure setpoint" is used as the conclusion part (consequence). These are then used in fuzzy inference using the control rule shown in Figure 7, the membership function shown in Figure 5, and the fuzzy set of the conclusion part (consequence) shown in Figure 6.

[0049] First, the "regenerated steam ratio" in the aforementioned condition section refers to the ratio of saturated steam S3 (regenerated steam) contained in saturated steam S4 discharged from header 3 in the circulation path 4, and is determined, for example, from a value measured by a flow meter (not shown) installed in header 3.

[0050] Furthermore, the aforementioned "second-stage compressor speed" refers to the rotational speed of compressor 5B, and as an example, it refers to the output value at the time of measurement relative to the pre-set optimal frequency of the inverter, which is set to 100%.

[0051] Furthermore, the aforementioned "first-stage compressor speed" refers to the rotational speed of compressor 5A, and as an example, it refers to the output value at the time of measurement relative to the optimal frequency of the inverter set in advance, which is set to 100%.

[0052] Furthermore, the "first-stage compressor suction pressure" refers to the pressure on the primary side of the first-stage compressor 5A in the circulation path 4, and is detected by the pressure sensor 43.

[0053] Furthermore, the "operation amount for the suction pressure set value of the first-stage compressor" in the conclusion (consequence) refers to the operation amount relative to the set value of the primary side pressure of the first-stage compressor 5A. In this embodiment, as an example, it is shown in Figure 6 as singletons of -1kPa, -0.3kPa, 0kPa, +0.3kPa, and +1kPa.

[0054] (i) Creating a membership function First, for the conditions of the fuzzy inference, namely "regenerative steam ratio," "second-stage compressor speed," "first-stage compressor speed," and "first-stage compressor suction pressure," the membership functions for the linguistic variables and attributes of each item are determined as shown in Figures 5(a) to 5(d). The number of such attribute language variables (labels), and the membership function for these language variables, are determined based on empirical rules and are tuned as appropriate depending on the type and properties of the object being processed, the scale and configuration of the system, etc.

[0055] (ii) Derivation of attributes and fitness and fuzzy inference Then, using the aforementioned membership function, the degree of fit for each attribute is derived. Subsequently, following the rules shown in Figures 7-1 to 7-4, the "regenerated steam ratio," "second-stage compressor speed," "first-stage compressor speed," and "first-stage compressor suction pressure" are used as the conditional part (antecedent), and the "operated value of the first-stage compressor suction pressure setting" is used as the conclusion part (consequence). Fuzzy inference is then performed using the fuzzy set shown in Figure 6. The manipulated variable, obtained as a result of calculations using fuzzy inference, is then added to the primary pressure setpoint of the first-stage compressor 5A, and the setpoint is changed accordingly.

[0056] Furthermore, by performing the fuzzy control described above, even if there are fluctuations in the evaporated moisture from the material being processed, the pressure on the primary side of the first-stage compressor 5A is changed to an appropriate setting, heat is recovered from the saturated steam S5 (carrier gas) without excess or deficiency to control the amount of saturated steam S1 produced, and saturated steam S4 with the exact amount of heat required by the dryer 1 can be obtained, enabling the operation of the indirect pressurized steam recompression type heat pump treatment device H. As a result, the operation of compressors 5A and 5B can be optimized according to the operating status of the indirect pressurized steam recompression type heat pump treatment device H, thereby enabling operation with reduced power consumption. Furthermore, by suppressing the release of saturated steam S2 into the system, energy loss can be reduced. Furthermore, since it becomes possible to operate the heat pump cycle to its fullest potential, the amount of auxiliary steam S0 required can be reduced, thereby reducing the energy consumption of the steam generator 30. Furthermore, since the introduction of outside air into the carrier gas S5 is suppressed, the load on the deodorization equipment can be reduced. Furthermore, since the complex control described above is performed using fuzzy control, the burden on the operator can be significantly reduced. [Explanation of Symbols]

[0057] 1 Dryer 10 Main Shell 101 Inlet 102 Overflow outlet 103 Carrier gas port 104 Exhaust port 105 Rotary Valve 106 Steam Inlet 107 Drain port 109 Outlet 11 Multi-tube heating tube (heating device) 111 Angle 112 End plate 113 Axis 114 Bearing Block 115a Rotary Joint 115b Rotary Joint 116 Tube bundle 117 Lifter 118 Feed vanes 2 Feeding device 20 Hoppers 3 Header 30 Steam generator 4 Circulation path 41 Drain Tank 43 Pressure Sensor 44 Steam flow meter 45 Heat exchanger 46 Pressure Sensor 47. Discharge valve 48 Induction valve 49 Drain discharge valve 5. Compressor 5A Compressor 5B Compressor 52 Casing 52a Rotor chamber 52b Screw chamber 53 Rotor 54 Screw 55 Air supply port 56 Exhaust vent 57 Water inlet 74 Temperature Sensor D0 Drain F machine frame H Drying and Concentration Equipment (Indirect Pressurized Steam Recompression Type Heat Pump Treatment System) M Motor P Pump S0 Auxiliary Steam S1 Saturated steam S2 Saturated Steam S3 Saturated Steam S4 Saturated Steam S5 Saturated vapor (carrier gas) S10 Outside air

Claims

1. A method for operating a heat pump type processing apparatus, which includes a continuous conduction heat transfer dryer equipped with a heating device inside the main shell, configured to evaporate moisture by bringing the workpiece into contact with the heat transfer surface of the heating device, The heat pump type treatment apparatus is configured to re-evaporate the heat transfer medium that has been discharged from the heating device as condensate after its temperature has dropped, then to increase its pressure and temperature using a compressor, and then to supply it back to the heating device for repeated use. Furthermore, this heating device is designed to dry the workpiece by exchanging heat with a heat transfer medium. The heat from the carrier gas containing water vapor evaporated from the material to be processed, which is discharged from the exhaust port formed in the main body shell, is taken into the heat transfer medium in the condensate state in the heat exchanger and re-evaporated. Furthermore, the compressor is provided with two compressors in series. First, the first-stage compressor reduces the pressure upstream of the first-stage compressor to promote the re-evaporation of the condensate heat transfer medium, while simultaneously making the pressure on the suction side of the second-stage compressor positive. In an operating method for an indirect pressurized steam recompression type heat pump treatment device, in which the second stage compressor subsequently increases the pressure so that the temperature of the heat transfer medium reaches a desired value, The rotational speed of the first-stage compressor is controlled so that the pressure on the primary side of the first-stage compressor reaches a predetermined value, thereby controlling the evaporation rate of the heat transfer medium in the heat exchanger. The conditions are defined as "regenerative steam ratio," "second stage compressor speed," "first stage compressor speed," and "first stage compressor suction pressure." A method for operating an indirect pressurized steam recompression type heat pump treatment device, characterized by performing fuzzy inference with the conclusion being "a set value manipulation amount for the suction pressure of the first stage compressor".

2. The method for operating an indirect pressurized steam recompression type heat pump treatment apparatus according to claim 1, wherein a mechanism for releasing the heat transfer medium to the outside is provided between the first-stage compressor and the second-stage compressor, and when the pressure of the heating medium between the first-stage compressor and the second-stage compressor exceeds a predetermined value, a portion of the heat transfer medium is released to the outside.

3. The heat exchanger is configured to allow outside air to be introduced into the carrier gas supplied to it. When there is excess thermal energy in the heat transfer medium discharged from the second stage compressor, A method for operating an indirect pressurized steam recompression type heat pump treatment apparatus according to claim 1 or 2, characterized in that outside air is introduced into the carrier gas supplied to the heat exchanger to reduce heat recovery to the heat transfer medium.

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