The constant temperature handpiece Water Chilling Units
Technical field
The utility model belongs to a kind of thermostatic equipment, is specifically related to water temperature stability property and is ± 0.1 ℃ high-end fixed handpiece Water Chilling Units frequently.
Background technology
The temperature stability of constant temperature handpiece Water Chilling Units except that depend on system to the external systems load variations in real time with the kinetic force, largely relevant with water tank shape and amount of capacity, heat insulation effect.The similar unit of existing market all adopts hot-gas bypass condenser or compressor electric motor converter technique; Adjust by-passing valve aperture or electric machine frequency with load variations by single PID control; Compressor is not shut down; System switches refrigeration and realizes unit cooling, heating with heat pump mode, promptly only strengthen one-of-a-kind system in real time with kinetic force.Above-mentioned heat takes up the frequency conversion mode when load variations, all needs the adjustment of middle transition section, and response speed is slow, and heat pump mode heating low-temperature adaptation ability becomes positive negative actuation because of cooling, heating respectively with load variations simultaneously, and single PID control model effect is unstable.To the other mode of heat, generally be equivalent to artificially produce a cooling load effect, before evaporimeter, introduce, normal to guarantee the compressor return air temperature, compressor is with 100% load continuous operation, meaningless increase energy consumption; Particularly multi-evaporator uses, and also need adopt overheated cooling expansion valve to cooperate with by-passing valve, behind evaporimeter, introduces, and prevents that suction temperature is lower than safety margin and damages unit; Because the muffler gas-liquid is directly mixed, gas-liquid separator is required height, cause system complex undoubtedly, increase investment and maintenance cost; To the frequency conversion mode, also need adopt hot-gas bypass during 30% underload, the frequency converter power consumption penalty reaches 15% simultaneously; It is big to produce electromagnetic interference in the frequent conversion process, and higher hamonic wave causes that electric machine temperature rise is big, the class of insulation requires height, and investment is bigger; It is more difficult to safeguard, range of application receives more limitations.
The utility model content
The technical problem that the utility model will solve is: a kind of constant temperature handpiece Water Chilling Units is provided, can guarantees water temperature stability property.
The utility model is to solve the problems of the technologies described above the technical scheme of being taked to be: a kind of constant temperature handpiece Water Chilling Units; It comprises water tank, refrigeration unit, controller, water tank heat detector, water tank temperature controller; Said refrigeration unit is made up of the water tank refrigerating circuit of a closure successively compressor, condenser, expansion valve, evaporimeter; Said evaporimeter and water tank heat detector are arranged in the water tank, and the signal of water tank heat detector output is through water tank temperature controller input controller;
It is characterized in that: also comprise first magnetic valve, second magnetic valve and gas-liquid separator in the refrigeration unit; Compressor, second magnetic valve, gas-liquid separator are formed the idle running loop of a closure successively, and first magnetic valve is arranged between condenser and the expansion valve, and first magnetic valve, second magnetic valve are controlled by controller.
Press such scheme, comprise also in the refrigeration unit that the 3rd magnetic valve, capillary, constant temperature handpiece Water Chilling Units also comprise body heat detector and body temperature controller, the body heat detector is arranged on the compressor, and the output signal of body heat detector is through body temperature controller input controller;
Said compressor, condenser, the 3rd magnetic valve, capillary, gas-liquid separator are formed the body hydrojet cooling circuit of a closure successively, and the 3rd magnetic valve is controlled by controller.
Press such scheme, the constant temperature handpiece Water Chilling Units also comprises heater, and heater is arranged in the water tank, and heater is controlled by controller.
Press such scheme, said water tank temperature controller comprises a PID temperature controller and the 2nd PID temperature controller that is used for control heater that is used to control refrigeration unit.
The control method of constant temperature handpiece Water Chilling Units is characterized in that: it may further comprise the steps:
Step (1), water tank heat detector are measured the temperature of water in the water tank and are exported signal;
Step (2), a PID temperature controller, the 2nd PID temperature controller receive water tank heat detector output signal, and make following selection:
The 2nd PID temperature controller selects to start heater, and the startup of controller control heater is also closed first magnetic valve;
Or the 2nd PID temperature controller selects not start heater, and a PID temperature controller is selected to open first magnetic valve, returns step (1);
Or the 2nd PID temperature controller selects not start heater, and a PID temperature controller is selected to close first magnetic valve, and controller cuts out first magnetic valve;
Step (3), body temperature controller receiver body temperature sensor output signal, and make following selection:
The body heat detector is measured temperature greater than design temperature, and the body temperature controller is closed second magnetic valve and opened the 3rd magnetic valve through controller;
Or the body heat detector is measured temperature smaller or equal to design temperature, and the body temperature controller is closed the 3rd magnetic valve and opened second magnetic valve through controller;
Step (4), return step (1).
The beneficial effect of the utility model is:
1, stop cooling must stopping compressor different with traditional, the utility model makes compressor and gas-liquid separator be set as the idle running loop when water tank temperature is constant, makes to keep when compressor is not shut down dallying, with energy efficient.
2, can raise and influence the work of compressor when compressor is in when idle running organism temperature for a long time; Even infringement compressor; Therefore set the body hydrojet cooling circuit of a compressor-condenser-capillary-gas-liquid separator-compressor; When the compressor block temperature surpasses setting value, the 3rd magnetic valve is moved and open body hydrojet cooling circuit, to cooling compressor by the control of body temperature controller.
3, adopt two PID temperature controllers according to the control heater and be arranged on first magnetic valve of water tank refrigerating circuit respectively of the water temperature in the water tank, guarantee the constant effect of water temperature to reach; And adopt existingly, introduce water temperature temperature difference Online Auto-tuning PID parameter, improve the adaptive performance of PID, guarantee dynamic quality and lasting accuracy simultaneously from the Tuning PID Controller mode.
4, compare the utility model good constant-temperature effect with frequency conversion and hot-gas bypass technology; Adopt this snap switch device of magnetic valve, stable performance, fault rate is low, is prone to maintenance, reduced investment; Cooling, heating are declared working condition, and efficient is high, and operating cost is low.
Description of drawings
Fig. 1 is the system block diagram of the utility model one embodiment.
Fig. 2 is the refrigeration system artwork.
Fig. 3 is the elementary diagram of PID temperature controller and PLC controller.
Fig. 4 is system's control flow chart.
The specific embodiment
Present embodiment is selected paddy wheel screw compressor, refrigerating capacity 20000W, and water tank 120L adopts Delta DVP-PLC Programmable Logic Controller, two Omrons digital temperature control device, realizes two PID controls through it from the pattern of adjusting.Fig. 1 is the system block diagram of the utility model one embodiment; Fig. 2 is the refrigeration system artwork; Comprise water tank, refrigeration unit, controller, water tank heat detector, water tank temperature controller; Said refrigeration unit is made up of the water tank refrigerating circuit of a closure successively compressor, condenser, expansion valve, evaporimeter, said evaporimeter and water tank heat detector are arranged in the water tank, and the signal of water tank heat detector output is through water tank temperature controller input controller.
Also comprise first magnetic valve, second magnetic valve and gas-liquid separator in the refrigeration unit; Compressor, second magnetic valve, gas-liquid separator are formed the idle running loop of a closure successively, and first magnetic valve is arranged between condenser and the expansion valve, and first magnetic valve, second magnetic valve are controlled by controller.
Also comprise the 3rd magnetic valve, capillary in the refrigeration unit, the constant temperature handpiece Water Chilling Units also comprises body heat detector and body temperature controller, and the body heat detector is arranged on the compressor, and the output signal of body heat detector is through body temperature controller input controller; Said compressor, condenser, the 3rd magnetic valve, capillary, gas-liquid separator are formed the body hydrojet cooling circuit of a closure successively, and the 3rd magnetic valve is controlled by controller.
The constant temperature handpiece Water Chilling Units also comprises heater, and heater is arranged in the water tank, and heater is controlled by controller.
The water tank temperature controller comprises a PID temperature controller and the 2nd PID temperature controller that is used for control heater that is used to control refrigeration unit.
The present embodiment middle controller is selected the PLC controller for use, and Fig. 3 is the elementary diagram of PLC controller, and PLC is Delta DVP series of products; The water tank temperature controller is Omron E5AZ digital temperature controller series of products, and this temperature controller adopts two PID temperature controller modes, promptly comprises a PID temperature controller and the 2nd PID temperature controller.The body temperature controller selects for use the Nereid to create the MTC-2000 temperature controller that machine Manufacturing Co., Ltd produces.1,3 pins of MTC-2000 temperature controller connect AC power, and 6, No. 7 pin connects refrigeration compressor, 9, No. 10 pins body temperature sensor of meeting sb. at the airport.Target water temperature and body design temperature are set respectively on water tank temperature controller and cabinet temperature controller earlier before using.
Fig. 4 is system's control flow chart, and it may further comprise the steps:
Step (1), water tank heat detector are measured the temperature of water in the water tank and are exported signal;
Step (2), a PID temperature controller, the 2nd PID temperature controller receive water tank heat detector output signal, and make following selection according to target temperature:
The 2nd PID temperature controller selects to start heater, and the startup of controller control heater is also closed first magnetic valve;
Or the 2nd PID temperature controller selects not start heater, and a PID temperature controller is selected to open first magnetic valve, returns step (1);
Or the 2nd PID temperature controller selects not start heater, and a PID temperature controller is selected to close first magnetic valve, and controller cuts out first magnetic valve;
Step (3), body temperature controller receiver body temperature sensor output signal, and make following selection:
The body heat detector is measured temperature greater than design temperature, and the body temperature controller is closed second magnetic valve and opened the 3rd magnetic valve through controller;
Or the body heat detector is measured temperature smaller or equal to design temperature, and the body temperature controller is closed the 3rd magnetic valve and opened second magnetic valve through controller;
Step (4), return step (1).