JP2009008045A - Detection device of drainage discharge abnormality and compressed air dehumidification device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive detection device of a drainage discharge abnormality quickly detecting a discharge abnormality of drainage, and to provide a compressed air dehumidification device. <P>SOLUTION: Drainage accumulated in a drainage receiver 23 is discharged by opening a solenoid valve 24. The detection device includes: a temperature sensor 26 disposed to a tee 25 attached on an output side of the solenoid valve 24; and a control part 4 controlling to open/close the solenoid valve 24. If a temperature difference, detected by a temperature sensor 26, before and after the control part 4 controls to open/close the solenoid valve 24, is smaller than a predetermined temperature difference, the control part 4 performs abnormality determination. In this case, it is preferable that the temperature sensor 26 may be disposed to a branch pipe of the tee. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a drain discharge abnormality detection device that discharges accumulated drain water by opening and closing a solenoid valve, and a compressed air dehumidifying device including the detection device.

  Equipment that uses compressed air as a power source is installed in factories and laboratories. Between these devices and an air compressor (air compressor), a dehumidifying device for removing moisture from the compressed air is provided, and dried compressed air is supplied.

  In the compressed air dehumidifier, drain water is generated by separating moisture in the air. In the cooling type compressed air dehumidifier, moisture is condensed and separated by cooling the compressed air in the heat exchanger. The separated drain water is temporarily stored in the drain receiver in the heat exchanger. Since there is high-pressure compressed air in the heat exchanger, the drain water cannot be discharged at all times. For example, when a certain amount of time has passed or when a certain amount of water has accumulated, it is discharged to the outside.

  Drain water is discharged automatically when a solenoid valve is placed between the drain receiver and the drain discharge flow path to temporarily open it to discharge drain water together with compressed air, or when a certain amount of drain water accumulates. This is done by arranging a drain trap with a mechanism that drains the drain water.

  If drain water is not discharged due to failure of the solenoid valve or drain trap or freezing of drain water, it will cause damage to equipment that uses compressed air as a power source due to a decrease in dehumidification performance.

  Confirmation of drain water discharge has been performed by the presence or absence of the operation sound of the solenoid valve and the presence or absence of the drain water discharge visually, but it is difficult for the operator to always confirm.

  For this reason, a pair of electrodes are arranged on the drain receiving upper part, and when the water level of the drain water rises and reaches the electrodes, an abnormal discharge is performed.

  As another abnormality detection device, Patent Document 1 provides a pair of electrodes in the drain water discharge flow path of the drain trap to detect drain water automatically discharged from the drain trap. A drain trap abnormality detection device that determines that the drain trap is abnormal when the time (period) being discharged or the discharge time interval is outside the set range is shown.

JP 2003-343794 A

  The conventional drain discharge abnormality detection device has a problem that the price of the device becomes high because an expensive electrode is arranged. Moreover, in the apparatus which has determined abnormality based on the detected discharge time and discharge interval in Patent Document 1, the drain trap operates when a certain amount of drain accumulates, and the operation interval is unknown. It is necessary to provide a margin for the judgment range. For this reason, there exists a problem that it takes time until it determines with it being abnormal. For example, when the drain water is not discharged due to freezing, the drain water will be frozen unless the compressed air dehumidifier is stopped quickly. Since the compressed air dehumidifier cannot be restarted again unless all the frozen drain water is dissolved, it is necessary to detect freezing as soon as possible.

  The present invention has been made to solve such a problem, and aims to provide a drain discharge abnormality detection device and a compressed air dehumidification device that are inexpensive and can quickly detect drain water discharge abnormality. To do.

  The drain discharge abnormality detection device according to claim 1, which has been made to achieve the above object, is disposed in a drain discharge flow path downstream of an electromagnetic valve that discharges drain water. A temperature sensor that detects temperature, a control unit that controls opening / closing of the electromagnetic valve, and a temperature difference detected by the temperature sensor before and after the control unit controls opening / closing of the electromagnetic valve is smaller than a predetermined temperature difference And a determination unit for determining abnormality.

  The drain discharge abnormality detection device according to claim 2 is the detection device according to claim 1, wherein a cheese mother pipe constituting a part of the drain discharge flow path is connected to the electromagnetic valve, The temperature sensor is disposed in the branch pipe of the cheese.

  The drain discharge abnormality detection device according to claim 3 is the detection device according to claim 2, wherein the tip of the temperature sensor is located at substantially the same position as the inner wall surface of the mother pipe at the branch pipe inlet of the cheese. It is characterized by being arranged in.

  A compressed air dehumidifying device according to claim 4 is a compressed air dehumidifying device comprising the drain discharge abnormality detecting device according to claim 3, wherein the compressed air dehumidifying device is in a state of performing a dehumidifying operation of compressed air. When the determination unit of the drain discharge abnormality detection apparatus determines an abnormality, the drain discharge abnormality is determined.

  According to the drain discharge abnormality detecting device according to claim 1, a temperature sensor that is less expensive than the electrode is disposed in the drain discharge flow path, and the temperature sensor is detected before and after the solenoid valve is controlled to open and close by the control unit. When the temperature difference in the temperature of the drain discharge flow path is smaller than the predetermined temperature difference, the determination unit makes an abnormality determination. For this reason, it is possible to quickly detect an abnormality after performing the opening / closing control of the electromagnetic valve. In addition, an inexpensive drain discharge abnormality detection device can be provided.

  According to the drain discharge abnormality detection device according to claim 2, the cheese main pipe constituting a part of the drain discharge flow path is connected to the electromagnetic valve, and the temperature sensor is arranged in the cheese branch pipe. Since the distance from the solenoid valve to the temperature sensor is short, the drain water discharged immediately hits the temperature sensor. Therefore, as the drain water passes through the discharge channel, the drain water is applied to the temperature sensor before the temperature of the drain water approaches the temperature of the discharge channel. Can be detected quickly and stably. Moreover, since cheese is a general-purpose part and inexpensive, it can provide an inexpensive drain discharge abnormality detection device.

  According to the drain discharge abnormality detecting device according to claim 3, the tip of the temperature sensor is arranged at the same position as the surface of the inner wall surface of the mother pipe at the inlet of the cheese branch pipe, so that the drain discharge of the compressed air dehumidifier is performed. When the present invention is applied to the apparatus, the temperature in the discharge channel can be measured without the temperature sensor directly receiving the water pressure of drain water that is discharged with high pressure compressed air when the solenoid valve is opened. . Therefore, repeated fatigue failure of the temperature sensor due to water pressure can be prevented.

  According to the compressed air dehumidifying apparatus of the fourth aspect, when the determination unit of the drain discharge abnormality detecting device makes an abnormality determination while the compressed air dehumidifying operation is being performed, the drain discharge abnormality is determined. For this reason, the determination according to the dehumidification load is performed, and the drain discharge abnormality can be accurately detected.

Preferred form for carrying out the invention

  Examples of the present invention will be described in detail below, but the scope of the present invention is not limited to these examples.

  FIG. 1 is a block diagram of a compressed air dehumidifier equipped with a drain discharge abnormality detection device to which the present invention is applied. The compressed air dehumidifier 1 includes a refrigeration cycle unit 2, a warning unit 3, and a control unit 4 as shown in FIG.

  In the refrigeration cycle unit 2, a heat exchanger in which an inverter compressor 11, a condenser 12, an inverter condenser fan 13, a refrigerant strainer 14, an electronic expansion valve 15, a capillary tube 16, and an evaporator 17 are arranged. 18 is provided. The refrigerant passes through the compressor 11, the condenser 12, the refrigerant 12, the refrigerant strainer 14, the electronic expansion valve 15, the capillary tube 16, and the evaporator 17 connected to the pipe and circulates in the compressor 11, whereby the evaporator 17 is cooled. The

  The heat exchanger 18 has an inlet 21 for introducing wet compressed air, an outlet 22 for discharging dry compressed air, a drain receiver 23, a solenoid valve 24, a cheese 25, a temperature sensor 26, and ball valves 27 and 28. Is provided. The drain receiver 23 is disposed at the bottom of the heat exchanger 18 and temporarily stores drain water. Further, the drain receiver 23 is connected to one end of each of the ball valve 27 and the ball valve 28 through a branch pipe branched into two. The ball valves 27 and 28 are valves that are manually opened and closed. The other end of the ball valve 27 is connected to the input portion of the electromagnetic valve 24 via a pipe 29.

  One end of a mother pipe of cheese 25 sold as a general-purpose product is connected to the output portion of the electromagnetic valve 24. A drain discharge pipe 30 is connected to the other end of the cheese 25. A temperature sensor 26 is provided in the branch pipe of the cheese 25.

  A drain discharge pipe 31 is connected to the other end of the ball valve 28. The ball valves 27 and 28 are operated when the drain water is forcibly discharged from the drain receiver 23 when the electromagnetic valve 24 fails.

  Further, the refrigeration cycle unit 2 includes, as sensors, an ambient temperature sensor 51 that detects the ambient temperature, a refrigerant condensation temperature sensor 52 that detects the temperature of the refrigerant that has passed through the condenser 12, and the temperature of the refrigerant that is discharged from the compressor 11. A refrigerant discharge temperature sensor 53 to detect, an evaporator refrigerant temperature sensor 54 to detect the temperature of the refrigerant entering the evaporator 17, a dew point temperature sensor 55 to detect the dew point temperature of the dehumidified compressed air in the heat exchanger 18, and heat exchange An air pressure sensor 56 for detecting the pressure of the compressed air in the compressor 18 and a refrigerant suction temperature sensor 57 for detecting the temperature of the refrigerant sucked by the compressor 11 are provided. Each of these sensors is connected to the control unit 4 (not shown).

  The warning unit 3 is provided with a display circuit 35 for displaying the content of the warning and a sounding circuit 36 for reporting a warning sound.

  The control unit 4 corresponds to the control unit and the determination unit according to the present invention, detects the temperature of each part of the compressed air dehumidifying device 1 including the refrigeration cycle unit 2 and the warning unit 3, and based on the detection result, The compressed air dehumidifier 1 is operated by controlling the operation. The control unit 4 includes a central processing unit, a ROM (Read Only Memory) that stores an operation program, a RAM (Random Access Memory) that stores an operation state, and the like.

  The control unit 4 is connected to the electromagnetic valve 24 and performs opening / closing control of the electromagnetic valve 24. Moreover, the temperature sensor 26 is connected to the control part 4, and the temperature of the drain discharge flow path (inside the cheese 25) is detected.

  Moreover, the control part 4 detects the quantity (pressure) and dry state (dew point temperature) of the compressed air pumped from an air compressor based on the output of the sensors 51-57 distribute | arranged to each part of the refrigerating cycle part 2. At the same time, the compressor 11 and the condenser fan 13 are inverter-controlled so that the temperature and pressure of the refrigerant are in an appropriate operating range so that the compressed air is dehumidified to dry air having an appropriate dew point temperature.

  The control unit 4 is connected to the display circuit 35 and the sound report circuit 36 of the warning unit 3.

  FIG. 2 is a block diagram showing a temperature sensor 26 disposed in a drain discharge abnormality detecting device to which the present invention is applied. The temperature sensor 26 includes a temperature detection unit 26a, a base unit 26b, and a cable 26c. The temperature detection unit 26a is covered with an elongated cover and is formed in a waterproof structure, and a thermistor (not shown) is built in the front end portion thereof. This thermistor is connected to the cable 26c. The base part 26b is fixed to the temperature detection part 26a in a waterproof structure. Further, the base portion 26b is formed with a screw thread that can be screwed and fixed to the joint side with the temperature detecting portion 26a.

  FIG. 3 is a mechanism diagram showing a mechanical main part of a drain discharge abnormality detecting device to which the present invention is applied.

  A pipe 29 is connected to the input portion of the electromagnetic valve 24 using a fixing member 29a. One end of the mother pipe 25a of the cheese 25 is directly screwed into the output part of the electromagnetic valve 24. A fixing member 30a is fastened to the other end of the mother pipe 25a of the cheese 25, and a drain discharge pipe 30 is connected. The mother pipe 25a and the drain discharge pipe 30 of the cheese 25 correspond to the drain discharge passage of the present invention, and drain water is discharged through these. The electromagnetic valve 24 is connected to the control unit 4 by a cable 47.

  As shown in the figure, the temperature sensor 26 has a tip end portion of the temperature detecting portion 26a arranged at the entrance of the branch pipe 25b of the cheese 25 at substantially the same position as the surface of the inner wall surface of the mother pipe 25a. In other words, the tip of the temperature detection unit 26a is arranged so as not to protrude too much from the branch pipe 25b to the mother pipe 25a and to be retracted into the branch pipe 25b. The bushing 42, the barrel nipple 43, and the socket 44 are connected to the branch pipe 25 b to adjust the length so that the tip of the temperature detection unit 26 a is disposed at such a position, and the socket 44 is connected to the temperature sensor 26. The base portion 26b is screwed and fixed. The pipe branching off at the branch pipe 25b is blocked by the base part 26b screwed into the socket 44. A commercially available general-purpose product can be used for the bushing 42, the barrel nipple 43, and the socket 44. A cable 26 c of the temperature sensor 26 is connected to the control unit 4.

  Next, the operation of the compressed air dehumidifier 1 will be described. The ball valve 27 is fixed open, and the ball valve 28 is fixed closed.

  When the operation of the compressed air dehumidifier 1 is started, the refrigeration cycle unit 2 starts to operate under the control of the control unit 4 and the evaporator 17 is cooled. Note that the cooling of the evaporator 17 by the refrigeration cycle is a conventional technique, and a detailed description thereof will be omitted. When air pressure feeding is started by an air compressor (not shown), compressed air is introduced from the inlet 21 of the heat exchanger 18. The compressed air is cooled by the evaporator 17 and condensed to remove moisture. The dried compressed air is discharged from the discharge port 22 of the heat exchanger 18. Condensed condensed water gathers in the drain receiver 23 along the inner surfaces of the evaporator 17 and the heat exchanger 18.

  The control unit 4 normally controls the electromagnetic valve 24 to be closed. Since the electromagnetic valve 24 is closed, the drain water (condensed water) collected in the drain receiver 23 is blocked by the electromagnetic valve 24, fills the pipe 29 and the ball valve 27, and accumulates in the drain receiver 23.

  The control unit 4 controls the electromagnetic valve 24 to be opened for a short time each time a predetermined time elapses (every predetermined time). Further, the control unit 4 stores the temperature detected by the temperature sensor 26 in the RAM immediately before the electromagnetic valve 24 is controlled to be opened.

  When the electromagnetic valve 24 is opened by the control of the control unit 4, the drain water that has been blocked is vigorously passed through the mother pipe 25 a of the cheese 25 and the drain discharge pipe 30 by the pressure of the compressed air in the heat exchanger 18. Discharged. Due to the pressure of the compressed air, the drain water is immediately discharged just by opening the solenoid valve 24 for a short time. The solenoid valve 24 is immediately closed and controlled by the control of the control unit 4.

  When the drain water is discharged through the mother pipe 25a of the cheese 25, the drain water is also applied to the tip of the temperature detection part 26a of the temperature sensor 26 arranged at the inlet of the branch pipe 25b. For this reason, the temperature of the temperature detector 26a varies depending on the temperature of the drain water, and the temperature detected by the temperature sensor 26 varies. Since the drain water is generated by cooling condensation, it is usually lower than the ambient temperature.

  The control unit 4 inputs the temperature detected by the temperature sensor 26 after a predetermined time has elapsed in consideration of the thermal resistance of the temperature detection unit 26a after the opening / closing control. Next, the control unit 4 calculates a temperature difference between the temperature detected by the temperature sensor 26 and the temperature detected by the temperature sensor 26 stored in the RAM before opening control.

  If the drain water is discharged normally, the temperature difference becomes a predetermined temperature difference or more depending on the temperature of the drain water. If the drain water is not discharged, the drain water does not reach the temperature detection unit 26a of the temperature sensor 26. Therefore, the temperature difference becomes smaller than the predetermined temperature difference.

  When the temperature difference is equal to or greater than the predetermined temperature difference, the control unit 4 determines that the drain water is discharged normally and continues the operation of the compressed air dehumidifier 1.

  The control unit 4 performs opening / closing control of the electromagnetic valve 24 each time a predetermined time elapses after the opening / closing control of the electromagnetic valve 24 is performed. Each time, as described above, the control unit 4 stores the temperature detected by the temperature sensor 26 in the RAM immediately before the opening control of the solenoid valve 24, and the temperature difference from the temperature detected after the opening / closing control is a predetermined value. It is determined whether or not it is smaller than the temperature difference. When this temperature difference is equal to or greater than the predetermined temperature difference, the operation of the compressed air dehumidifier 1 is continued.

  When the temperature difference between the temperatures detected by the temperature sensor 26 before and after the opening / closing control of the electromagnetic valve 24 is smaller than a predetermined temperature difference, the control unit 4 determines that there is an abnormality.

  However, when the air compressor is stopped and the compressed air is not fed to the inlet 21 or when the compressed air is already dry, little drain water is generated. That is, when the compressed air dehumidifier 1 does not need to be dehumidified (no load), the drain water is hardly discharged even if the solenoid valve 24 is controlled to open. For this reason, even if the solenoid valve 24 is operating normally, there is no temperature difference between the temperature detected by the temperature sensor 26 before and after the solenoid valve 24 is opened and closed. Therefore, when detecting that the compressed air dehumidifier 1 is unloaded from the sensors 51 to 57 of the respective units, the control unit 4 does not determine whether or not the drainage is normal. That is, when the compressed air dehumidifying apparatus 1 is performing a dehumidifying operation of compressed air (when there is a load), the temperature detected by the temperature sensor 26 before and after the solenoid valve 24 is controlled to open and close. When the difference is smaller than the predetermined temperature difference, the drain discharge abnormality is determined.

  The control unit 4 immediately stops the operation of the refrigeration cycle unit 2 when the drain discharge abnormality is determined. At the same time, the control unit 4 displays a drain discharge abnormality character on the display circuit 35 of the warning unit 3 and outputs a high-volume warning sound from the reporting sound circuit 36. The operator can immediately know from the display and sound that a drain discharge abnormality has occurred.

  Workers who are aware of a drain discharge abnormality immediately stop using equipment that uses compressed air as a power source to prevent damage.

  The worker closes the ball valve 27 to prevent the drain water from accumulating on the electromagnetic valve 24 side, and opens the ball valve 28 to manually drain the drain water accumulated in the drain receiver 23. If the solenoid valve 24 is broken, repair it. When the drain water becomes abnormal because the drain water is frozen, the drain discharge abnormality is detected quickly, and the refrigeration cycle unit 2 is immediately stopped, thereby preventing the drain water from being frozen. For this reason, freezing melts quickly, and the operation of the compressed air dehumidifier 1 (particularly the refrigeration cycle unit 2) can be restarted quickly.

  Thus, according to the drain discharge abnormality detection device (the control unit 4, the cheese 25, the temperature sensor 26) applied to the compressed air dehumidifying device 1, the inexpensive temperature sensor 26 is arranged on the cheese 25 compared to the electrodes. The controller 4 determines that the temperature difference detected by the temperature sensor 26 is smaller than a predetermined temperature difference before and after the electromagnetic valve 24 is controlled to be opened and closed by the controller 4. For this reason, it is possible to quickly detect an abnormality after the opening / closing control of the electromagnetic valve 24 is performed. In addition, an inexpensive drain discharge abnormality detection device can be provided.

  Further, according to this drain discharge abnormality detection device, the mother pipe 25a of the cheese 25 constituting a part of the drain discharge flow path is connected to the electromagnetic valve 24, and the temperature sensor 26 is disposed in the branch pipe 25b of the cheese 25. As a result, since the distance from the solenoid valve 24 to the temperature sensor 26 is short, the drain water discharged is immediately applied to the temperature sensor 26. For this reason, since the drain water is applied to the temperature sensor 26 before the temperature of the drain water approaches the temperature of the discharge flow path as the drain water passes through the discharge flow path, the discharge flow path by drain water discharge The temperature change inside can be detected quickly and stably. Moreover, since the cheese 25 is a general-purpose component and is inexpensive, an inexpensive drain discharge abnormality detection device can be provided.

  Furthermore, according to this drain discharge abnormality detection device, the tip of the temperature sensor 26 (tip of the temperature detection unit 26a) is arranged at the entrance of the branch pipe 25b of the cheese 25 substantially in the same manner as the inner wall surface of the mother pipe 25a. Thus, when the present invention is applied to the compressed air dehumidifier 1, the temperature sensor 26 does not directly receive the water pressure of the drain water that is exhausted together with the high-pressure compressed air when the solenoid valve 24 is opened. The temperature in (cheese 25) can be measured. Therefore, repeated fatigue failure of the temperature sensor 26 due to water pressure can be prevented.

  Furthermore, according to the compressed air dehumidifying apparatus 1, when the controller 4 determines an abnormality from the temperature difference before and after the opening / closing control of the solenoid valve 24 in a state where the dehumidifying operation of the compressed air is being performed, the drain discharge abnormality is detected. Make a decision. For this reason, the determination according to the dehumidification load is performed, and the drain discharge abnormality can be accurately detected.

  In addition, although the drain discharge abnormality detection device to which the present invention is applied has been described as applied to a compressed air dehumidifier, the present invention is not limited thereto, such as a drain receiver such as an air conditioner or a refrigerator, an air tank of compressed air, etc. It can be applied to various devices that discharge drain water.

  Moreover, although the temperature sensor comprised with a thermistor was demonstrated, you may comprise a temperature sensor with a thermocouple, an infrared sensor, etc. Moreover, although the example which connected the temperature sensor 26 to the cheese 25 via the bushing 42, the barrel nipple 43, and the socket 44 was demonstrated, the bushing 42, the barrel nipple 43, and the socket 44 are alignment of the temperature detection part 26a, and It is used for fixing the temperature sensor 26 and is not necessary if the temperature sensor 26 can be aligned and fixed without using it. For example, only the bushing is used, or the other is used for alignment and fixing. May be.

It is a block diagram of a compressed air dehumidifying device provided with a drain discharge abnormality detecting device to which the present invention is applied. It is a block diagram which shows the temperature sensor distribute | arranged to the drain discharge abnormality detection apparatus to which this invention is applied. It is a mechanism figure which shows the mechanical principal part of the detection apparatus of the drain discharge abnormality which applies this invention.

Explanation of symbols

  1 is a compressed air dehumidifier, 2 is a refrigeration cycle unit, 3 is a warning unit, 4 is a control unit, 11 is a compressor, 12 is a condenser, 13 is a condenser fan, 14 is a refrigerant strainer, 15 is an electronic expansion valve, 16 is a capillary tube, 17 is an evaporator, 18 is a heat exchanger, 21 is an inlet, 22 is a drain, 23 is a drain receiver, 24 is a solenoid valve, 25 is cheese, 25a is a mother tube, 25b is a branch tube, 26 is a temperature sensor, 26a is a temperature detector, 26b is a base, 26c and 47 are cables, 27 and 28 are ball valves, 29 is piping, 29a and 30a are fixing members, 30 and 31 are drain discharge pipes, 35 Is a display circuit, 36 is an alarm circuit, 42 is a bushing, 43 is a barrel nipple, 44 is a socket, 51 is an ambient temperature sensor, 52 is a refrigerant condensation temperature sensor, 53 is a refrigerant discharge temperature sensor, and 54 is an evaporator refrigerant temperature sensor. , 55 dew-point temperature sensor, 56 is the air pressure sensor, 57 is a refrigerant suction temperature sensor.

Claims (4)

  A temperature sensor that detects the temperature disposed in the drain discharge flow path downstream of the solenoid valve that discharges drain water, a control unit that controls opening and closing of the solenoid valve, and before and after the control unit controls opening and closing of the solenoid valve An apparatus for detecting a drain discharge abnormality, comprising: a determination unit that determines an abnormality when a temperature difference between temperatures detected by the temperature sensor is smaller than a predetermined temperature difference.   2. The drain discharge abnormality according to claim 1, wherein a cheese mother pipe constituting a part of the drain discharge flow path is connected to the electromagnetic valve, and the temperature sensor is arranged in the branch pipe of the cheese. Detection device.   The drain discharge abnormality detecting device according to claim 2, wherein the tip of the temperature sensor is disposed at the same position as the inner wall surface of the mother pipe at the cheese branch pipe inlet.   A compressed air dehumidifying device comprising the drain discharge abnormality detecting device according to claim 3, wherein the determination unit of the drain discharge abnormality detecting device is abnormal when the compressed air is dehumidifying. A compressed air dehumidifier characterized by determining a drain discharge abnormality when determined.

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