JP4929044B2 - Switchboard temperature controller for compressed air dehumidifier - Google Patents

Description

  The present invention relates to a temperature control device that prevents the temperature of a switchboard of a compressed air dehumidifier from overheating.

  In sites such as factories and laboratories, compressed air (high pressure air) is supplied as an instantaneous power source or as a drying means. Since compressed air delivered from a compressed air source such as an air compressor contains moisture or oil mist, a dehumidifying device for cleaning the compressed air is arranged on the supply side of the compressed air source. Such a compressed air dehumidifier is disclosed in Patent Document 1, for example.

  The compressed air dehumidifying device performs cooling and dehumidification by a cycle in which a refrigerant is compressed and expanded by a compressor (compressor). Power supplies such as compressor motors, sensors, and other solenoid valves, or switchboards incorporating circuits and electrical components for controlling these power supplies are installed. When the sensor detects an increase in ambient temperature, it maintains the set dew point temperature, so that the control circuit operates to increase the frequency of the compressor motor power inverter, resulting in a decrease in the dew point temperature. However, when the frequency of the inverter is increased, the temperature inside the switchboard rises due to the waste heat of the compressor and the heat generated by the motor. An increase in the temperature of the switchboard causes deterioration of electrical components. Therefore, an alarm is displayed when the temperature inside the switchboard exceeds a certain temperature, and the operation is stopped.

JP 61-192324 A

  When the operation of the compressed air dehumidifier is stopped as in the prior art, the production line is stopped each time, and the production line is resumed after waiting for the temperature of the switchboard to drop. For this reason, the production efficiency has been poor.

  The present invention has been made to solve the above-described problem, and an object of the present invention is to provide a temperature control device that prevents the temperature of the switchboard from overheating without stopping the operation of the compressed air dehumidifier.

The switchboard temperature control device of the compressed air dehumidifying device according to claim 1, which has been made to achieve the above object, is characterized in that each of the main inverter compressor and the sub inverter compressor compresses the refrigerant. A compressed air dehumidifying device that cools and dehumidifies compressed air by an expansion cycle, and has a region for controlling the frequency of the main inverter and a region for controlling the frequency of the sub inverter in the control circuit. The frequency of at least one of the main inverter compressor and the sub-inverter compressor is controlled based on a temperature detected by a temperature sensor disposed on or near the switchboard on which the inverter is mounted. To do.

  The switchboard temperature control device of the compressed air dehumidifying device described in claim 2 is also the device described in claim 1, and is at least one of the main inverter compressor and the sub inverter compressor. Is always in steady operation, and the frequency of the remaining one inverter is controlled as described above.

  The switchboard temperature control device of the compressed air dehumidifying device according to claim 3 is the device according to claim 1, wherein the temperature sensor is a thermocouple mounted on the switchboard. .

  According to the switchboard temperature control device of the compressed air dehumidifier of the present invention, the operation of the compressed air dehumidifier is stopped when the inverter compressor is excessively loaded to lower the dew point temperature and the temperature of the switchboard rises. The temperature of the switchboard can be lowered without any problems. Therefore, since overheating of the switchboard can be prevented, deterioration of electrical components attached to the switchboard can be prevented. In addition, since the operation of the compressed air dehumidifier is not stopped, the production line in which the compressed air dehumidifier is installed is not stopped, and the production efficiency can be maintained.

Preferred form for carrying out the invention

  Hereinafter, preferred modes for carrying out the present invention will be described in detail with reference to the drawings, but the scope of the present invention is not limited to these embodiments.

  FIG. 1 is a schematic block diagram of an electrical main part showing an embodiment of a switchboard temperature control device of a compressed air dehumidifier to which the present invention is applied. This compressed air dehumidifier comprises two devices, a main (main) compressed air dehumidifier and a sub (sub) compressed air dehumidifier, both of which consist of the same elements.

  In this temperature control device, a control system of a main inverter compressor and a control system of a sub inverter compressor are connected to the control circuit 1. As temperature input means, dew point temperature sensors THE1, THE2 and a switchboard temperature sensor 4 are connected. The main inverter compressor includes a main inverter 12 and a main compressor motor 13, and the sub inverter compressor includes a sub inverter 22 and a sub compressor motor 23.

  FIG. 2 is a block diagram showing piping and a control system of the compressed air dehumidifier, in which the switchboard temperature controller of FIG. 1 is arranged. The control circuit 1 of the switchboard temperature control device includes a main controller 11 that is an area for controlling each element including the main inverter 12 and a sub-controller 21 that is an area for controlling each element including the sub inverter 22.

  In this embodiment, each element connected to the main controller 11 is equivalent to each element connected to the sub-controller 21. That is, the system connection block of the main controller 11 depicted in FIG. 2 and the system connection block of the sub-controller 21 are bilaterally symmetric. Therefore, only the system connection block of the main controller 11 is illustrated. A system connection block is not shown.

  A main compressor motor M1 is connected to the main inverter 12 connected to the main controller 11. A sub compressor motor M2 (see FIG. 1, omitted as described above in FIG. 2) is connected to the sub inverter 22 connected to the sub controller 21. The main controller 11 is connected with a dew point temperature sensor THE1, a discharge temperature sensor DTS1, and a suction temperature sensor STS1 as sensors. The discharge temperature sensor DTS1 and the suction temperature sensor STS1 correspond to the switchboard temperature sensor 4 of FIG.

  In addition, the compressed air dehumidifier of FIG. 2 includes a high pressure switch HPRS1, a high pressure sensor HPS1, a low pressure sensor LPS1, a refrigerant dryer D1, an electronic expansion valve EEV1, a water control valve WPV1, and an accumulator ACC1 in the series of the condenser COND1. The control solenoid valve SV1 of the capacity control valve CCV1 connected to is arranged. Further, a drain discharge electromagnetic valve DV1, a distributor DB1, DB4, and an air pressure gauge APG, and an antifreezing valve V1, which are connected to the ball valves BV1, BV2, which open and close the connection with the outside air of the cooler HE1, are arranged.

  The program shown by the flowchart in FIG. 3 is recorded in the memory area of the control circuit 1 in the switchboard temperature controller of the compressed air dehumidifier. Hereinafter, the control procedure of the switchboard temperature will be described with reference to this flowchart. One or both of the main compressed air dehumidifier and the sub compressed air dehumidifier are driven simultaneously. Since the control procedure of the switchboard temperature in both devices is the same, the control when only the main compressed air dehumidifier is driven will be described.

  In step 101, the main compressed air dehumidifier is driven. The frequency of the main inverter 12 is controlled by a steady operation control signal from the main controller 11 of the drive control circuit 1, the main compressor motor M1 rotates, the compressed air dehumidifier is operated in a steady state, and compression such as an air compressor is performed. Compressed air from an air source (not shown) is cooled and dehumidified.

  As the operation continues, the temperature of the switchboard rises due to the heat generated by the inverter and the motor M1. This is detected by the switchboard temperature sensor 4. If the temperature is lower than the set temperature (for example, 53 ° C.) in step 102, the operation is continued, and if the temperature is higher than the set temperature, the frequency of the inverter 12 is decreased by a predetermined cycle (for example, 5 Hz) ( Step 103). In a state where the frequency is lowered, the system waits for a predetermined time (for example, 60 seconds) in Step 104, and if the switchboard temperature detected by the switchboard temperature sensor 4 is equal to or higher than a set temperature (for example, 50 ° C.) (Step 105), from Step 105 Returning to Step 103, Step 103 → Step 104 → Step 105 is repeated.

  In step 105, the switchboard temperature falls below the set temperature. In step 106, if the dew point temperature by the dew point temperature sensor THE1 is less than the set temperature, the process returns to step 102. Step 102 → Step 103 → Step 104 → Step 105 → Step 106 is repeated. If the dew point temperature is equal to or higher than the temperature set in step 106, the frequency of the inverter 12 is increased by a predetermined cycle (for example, 3 Hz) (step 107). In a state where the frequency is increased, the process waits for a predetermined time (for example, 60 seconds) in step 108, returns to step 106, and repeats step 106 → step 107 → step 108.

  In this way, the drive of the main compressed air dehumidifier is controlled, and the switchboard temperature is maintained below a certain level while maintaining the dew point temperature above a certain level. Similarly, the drive of the sub compressed air dehumidifier is controlled, and the switchboard temperature is maintained below a certain level while maintaining the dew point temperature above a certain level. The drive of the main compressed air dehumidifier and the drive of the sub compressed air dehumidifier may be controlled simultaneously.

It is a schematic block diagram which shows one Example of the switchboard temperature control apparatus of the compressed air dehumidification apparatus to which this invention is applied. It is a block diagram which shows piping of one Example of the compressed air dehumidification apparatus to which this invention is applied, and a control system. It is a flowchart figure which shows the program of the control procedure of the control circuit in the switchboard temperature control apparatus of the compressed air dehumidification apparatus to which this invention is applied.

Explanation of symbols

  1 is a control circuit, 4 is a switchboard temperature sensor, 11 is a main controller, 12 is a main inverter, 13 is a main compressor motor, 21 is a sub-controller, 22 is a sub-inverter, 23 is a sub-compressor motor, ACC1 is an accumulator, APG Is an air pressure gauge, BV1 and BV2 are ball valves, CCV1 is a capacity control valve, COND1 is a condenser, D1 is a refrigerant dryer, DB1 and DB4 are distributors, DTS1 is a discharge temperature sensor, DV1 is a drain discharge solenoid valve, EEV1 is an electronic expansion valve, HE1 is a cooler, HPRS1 is a high pressure switch, HPS1 is a high pressure sensor, LPS1 is a low pressure sensor, M1 is a main compressor motor, M2 is a sub compressor motor, STS1 is an intake temperature sensor, SV1 Is the control power Valve, The1, THE2 the dew-point temperature sensor, V1 antifreezing valve, is WPV1 a water control valve.

Claims (3)

A compressed air dehumidifying device that cools and dehumidifies compressed air by a cycle in which each of the main inverter compressor and the sub-inverter compressor compresses and expands the refrigerant, and the control circuit includes a region for controlling the frequency of the main inverter. An area for controlling the frequency of the sub-inverter, and based on the temperature detected by a temperature sensor disposed on or near the switchboard to which the control circuit is attached, the main inverter compressor and the sub-inverter compressor A switchboard temperature control device for a compressed air dehumidifier, wherein the frequency of at least one of the inverters is controlled.   2. The compressed air dehumidifier according to claim 1, wherein at least one of the main inverter compressor and the sub inverter compressor is always in a steady operation, and the frequency of the remaining one inverter is controlled as described above. Switchboard temperature control device.   2. The switchboard temperature control device for a compressed air dehumidifier according to claim 1, wherein the temperature sensor is a thermocouple mounted on the switchboard.

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