JP2015519533A - Cooling amount control device, test device using the control device, and control method thereof - Google Patents

Abstract

The present invention relates to a cooling amount control apparatus, a test apparatus using the control apparatus, and a control method. The cooling amount control device includes a compressor 2, a condenser 5, an evaporator 7, a controller 1, a pressure adjustment valve 4, a throttle device 6, a hot air valve drive control panel 13, and a hot air valve 11. The control device is connected to the hot air valve 11 via a hot air valve drive control panel. The pressure regulating valve 4 is provided between the outlet of the compressor 2 and the inlet of the condenser 5 of the cooling device. The expansion device 6 is provided with an outlet of the condenser 5 and an inlet of the evaporator 7. One end of the hot air valve 11 is provided in a pipeline between the outlet of the compressor and the front end of the compression regulating valve 4, and the other end is in a pipeline between the rear portion of the expansion device 6 and the inlet of the evaporator 7. Provided.

Description

  The present invention relates to a hot air valve hot air bypass cooling amount control device for accurately controlling the cooling amount of a climate and environmental test apparatus. The test device using the above control device can maintain the cooling system operating at a temperature close to or higher than the ambient temperature with little or no use of heating, thereby reducing the energy consumption of heating, You can improve energy efficiency and not even use a heater. The control device has a simple configuration and low energy consumption. This can be used as an important tool for high-precision temperature control of climatic and environmental test equipment. Furthermore, the invention likewise relates to a test device using a control device and a method used for such a control device.

   The climate and environmental test equipment includes thermostatic tanks and thermocirculators, climate and environmental test chambers and bio-population climate test chambers, cryostats, etc., medical hygiene, biotechnology, agriculture and forestry research, electricity and electronics, metrology It can be widely applied in the fields of production verification, geotechnical engineering, petrochemistry, etc., scientific research and laboratory.

The cooling device is one of the important devices indispensable for climate and environmental test equipment. Cooling devices and techniques apply to all systems that require low temperatures (lower than ambient temperature) or heat dissipation during normal operation. The amount of cooling and energy consumption control has been important but has been ignored so far due to the demands of precise temperature control and climate and environmental test equipment in small quantities and diverse application features. Temperature control for almost all climate and environmental test equipment is based on the prior art of continuous cooling and additional heating compensation, resulting in large amounts of energy consumption and waste.

As shown in FIG. 1, the conventional cooling device basically includes a compressor, a condenser, a throttle device, and an evaporator. The expansion device is an indispensable part of the cooling device, and has various types such as capillaries, thermal expansion valves and electronic expansion valves, demonstrating an advanced course of cooling technology from simple to automatic control. The role of the electronic expansion valve is becoming increasingly important for high-precision control of the cooling device.

Regarding cooling control, frequency conversion compressor cooling technology, electronic expansion valve throttle technology, and modern heat pump technology are widely used in household and commercial appliances. The cooling technology of the frequency conversion compressor and the throttle technology of the electronic expansion valve are generally incorporated in the cooling device as a whole for controlling the cooling amount. The success in products of such technology involves specific frequency conversion compressors and complex heating verification and calculations, without designing sufficient unfunded or mass-produced products for manufacturing investment, It is difficult to apply this technology to products and devices for general use. Compared with traditional resistive electric heating, superheat in evaporator and condenser heat pump technology has a very high energy efficiency ratio, and realizes switching between heating and cooling in it. However, the cooling amount control needs to be based on the technology of the frequency conversion compressor and the electronic expansion valve.

In recent years, electronic expansion valves have been widely used in the field of home appliances and commercial refrigerators. In particular, it is used as a throttle device and meets the system requirements of inverter / compressor refrigerators. Its key function is to control the superheat temperature at the outlet of the evaporator.
The electronic expansion valve is usually provided between the outlet of the condenser and the inlet of the evaporator. Based on the demand for superheat temperature at the outlet of the evaporator, the electronic expansion valve analyzes and determines the size of the valve opening in real time, the control to the degree of heating is optimized, and the export of the system cooling device To be optimized. However, since the degree of heating was limited when accurately controlling, the cooling export control function could not be optimized, and the system temperature control was deteriorated. For example, in order to obtain a high-precision overheat valve, it is often required to measure the evaporation temperature and / or the cooling pressure before and after the evaporator. Therefore, the complexity and reliability of the control circuit and software algorithm are important for system success. It is difficult to afford large costs for a sophisticated and reliable system without an optimistic view of industrialization and budget for mass engineering and manufacturing investments. By the way, the application requirements in the climate and environmental test apparatus have been expanded to −90 ° C. below and + 300 ° C. above, while the application temperature of the conventional electronic expansion valve is limited to between the ambient temperature and −40 ° C. Therefore, it is difficult to apply an electronic expansion valve in a high-accuracy temperature climate and environmental test apparatus in a small and diverse situation in applications.

  An auxiliary hot air bypass channel is added to the pipeline in the conventional cooling device to achieve simple normal cooling and hot air bypass heating. Its basic operating principle is to close the hot air bypass for maximum cooling when fast cooling is required. When there is a need to reduce the amount of cooling or when there is a request for heating, the hot air bypass valve is opened, and the high-temperature cooling steam from the outlet of the compressor is bypassed directly to the evaporator without being cooled by the condenser. As a result, the amount of cooling is suppressed and heating is possible. When a constant temperature is required, the high-temperature bus bypass valve opens and closes at a certain period to adjust the cooling amount and achieve a constant temperature. Although they are well-known knowledge, the current hot air bypass technology has the following disadvantages.

(1) The operation interval of the hot air bypass is limited to some extent due to restrictions from the life of the solenoid valve. As a result, the control accuracy of the cooling amount is limited.

(2) If the solenoid valve is kept open for a long time in a continuous heating state, the discharge pressure of the compressor gradually decreases. As a result, the cooling device is only capable of limited heating or non-heating. In practice, it is difficult to maintain operation near or above ambient temperature.

(3) Due to the function and operation of the solenoid valve, there are undesirable noises including valve operation and hot air flow noise.

(4) Pressure shock stress resulting from the operation of the solenoid valve causes additional fatigue and shortens the life of the associated cooling components and elements including the solenoid valve itself.

The present invention relates to a cooling amount control device having technical difficulties in control of the cooling amount system in the climate and environmental test apparatus, temperature adjustment and energy saving,
A climate and environmental test device using the claimed control device;
And a control method used in the climate and environmental test apparatus.

The technical solution of the present invention of the related technical difficulties mentioned is
A controller, a cooling device connected to the hot air valve via an evaporator and a condenser hot air valve drive control panel, and a pressure regulating valve provided between the compressor outlet and the condenser inlet of the cooling device; A throttle device connected to the outlet of the condenser and the inlet of the evaporator of the cooling device, one end of which is provided in the pipeline between the outlet of the compressor and the front end of the compression regulating valve, A cooling amount control device having a hot air valve provided at a pipeline between a rear portion of the throttle device and an inlet of the evaporator and a hot air valve driving control panel.

  The cooling amount control device as claimed in claim 1, wherein the expansion device is a thermal expansion valve.

  The cooling amount control device as claimed in claim 1, wherein the throttle device is a capillary tube.

  The cooling amount control device as claimed in claim 1, wherein the throttle device is an electronic expansion valve.

  The above-described cooling amount control device, wherein the hot air valve is an electric valve that opens and closes continuously or an electromagnetic valve that opens and closes intermittently.

  The cooling device includes a compressor, an evaporator, and a condenser connected in series through a pipeline.

  The test apparatus includes the cooling amount control device, a constant temperature tank or a constant temperature bath, and a temperature sensor, and all the evaporators that can be placed in the temperature sensor and the cooling amount control device are provided in the constant temperature tank or the constant temperature bath. The temperature sensor is connected to a controller of the cooling amount control device.

  In the cooling amount control method, first, the pressure adjusting valve is provided between the compressor and the condenser of the conventional cooling device, and then one end of the hot air valve is connected to the outlet of the compressor and the compression. The controller is provided in a pipeline between the front end of the regulating valve and the other end is provided in a pipeline between the rear portion of the throttle device and the inlet of the evaporator, and the controller is provided via a hot air valve drive control panel. The pressure regulating valve ensures a stable discharge pressure and hot air temperature, avoids affecting the discharge pressure by opening and closing the hot air valve, and the throttle device is connected to the condenser outlet of the cooling device. The hot air valve is provided between the inlet of the evaporator and used for self-adjusting the evaporation temperature and the degree of superheat. , Bypass directly, cool into condenser Agent is suppressed by the operation of the compression regulating valve, lowering the cooling export system, the temperature of the test apparatus can be efficiently controlled heating or cooling, is maintained at a high precision and the value set.

  The hot air valve is an electric valve that opens and closes continuously or an electromagnetic valve that opens and closes intermittently.

  It is an advantageous effect of the present invention that a conventional electric valve or electromagnetic valve is used as a hot air bypass valve and is combined with a conventional expansion valve to constitute a cooling device. As a result, even when the cooling device operates under an operating temperature lower than −30 ° C., or even when the opening of the hot air bypass valve is larger than necessary, it is widely required in climate and environmental test equipment. High-accuracy control for the amount of cooling of 300 W to 15 kW or higher and high-accuracy temperature control of the cooling device operating between −90 to + 20 ° C. is easily realized. The technology of the present invention becomes one of the most important control devices of a cooling device for a climate and environmental test device that requires high-precision control of the cooling amount and temperature. The conventional temperature expansion valve or capillary tube has the disadvantage that the amount of cooling cannot be controlled randomly and smoothly, and the electronic expansion valve applicable to commercial products has a feature that it has a large opening for excessive cooling amount and low control accuracy. The shortcoming of being can be removed.

FIG. 1 shows a block diagram of a conventional cooling device.
FIG. 2 shows a configuration diagram of a test apparatus using the cooling amount control apparatus claimed in the present invention.

1. Controller 2. Compressor 3. Condensation fan 4. Pressure regulating valve 5. Condenser 6. Throttle device 7. Evaporator 8. Circulating fan or pump 9. Constant temperature tank or constant temperature tank 10. Temperature sensor 11. Electronic expansion valve 12. Cooling pipeline 13. Hot air valve drive control panel

Detailed Description of the Preferred Embodiments of the Invention

  Here, referring to FIG. 1 in which reference numerals indicate components, as shown in FIG. 2, a test apparatus using the cooling amount control apparatus according to the present invention includes a controller 1, a compressor 2, and a condensing fan 3. The pressure regulating valve 4, the condenser 5, the expansion device 6, the evaporator 7, the circulation fan or pump 8, the constant temperature tank or constant temperature tank 9, the temperature sensor 10, the electronic expansion valve 11, and the cooling. It has a pipeline 12 and a hot air valve drive control panel, and the compressor 2, the compressor 5, the expansion device 6 and the evaporator 7 are connected in series via the cooling pipeline 12. The condensing fan 3 is used for cooling cooling in the compressor 5, and the circulation fan or pump 8 is used for improving heat exchange and improving heat dispersion in the thermostatic tank or thermostatic bath 9. The electronic expansion valve 11 has one end connected to the pipeline between the outlet of the compressor and the inlet of the pressure regulating valve, and the other end connected to the pipeline between the rear portion of the expansion device and the evaporator. State, connected in parallel. The hot air valve drive control panel 13 receives a drive signal such as voltage or current from the controller 1 and directly regulates the opening and closing of the electronic expansion valve 11 and the degree of opening. Depending on its function and specifications, the controller 1 is basically controlled by being connected to a compressor 2, a temperature sensor 10, a condensing fan 3, a circulation fan or pump 8, and a control panel 13 for driving hot air valves. To do. The temperature sensor 10 and the evaporator 7 are located in a constant temperature tank or a constant temperature tank 9 where temperature control for heating, cooling and temperature maintenance are required.

  The controller 1 can start and stop the operation of the compressor 2, the condensation fan 3, the circulation fan or the pump 8. By using the temperature sensor 10, the controller 1 can detect the temperature of air or liquid (heat transfer medium) in the thermostatic tank or the thermostatic chamber 9. When the actual temperature is higher than the set temperature of the controller 1, the opening of the electronic expansion valve 11 is made smaller. On the other hand, when the actual temperature is lower, the opening of the electronic expansion valve 11 is made larger. When the actual temperature is stabilized, the opening degree of the electronic expansion valve 11 tends to be constant.

The compressor 2, the compressor 5, the expansion device 6 and the evaporator 7 are basic components of a conventional cooling device. The function of the compressor 2 is to compress the low pressure / normal temperature coolant vapor from the evaporator 7 into a high pressure / high temperature coolant vapor. Conventional compressor 2 models include a reciprocating engine, a rotary, a scroll, and a screw. The function of the condenser 5 is to convert the vapor of the high-pressure / high-temperature coolant into a high-pressure / normal temperature liquid by radiative cooling of the condensing fan 3 or other liquid refrigerant.
The condenser 5 may be any type such as a fin tube, a sleeve, a shell tube, and a plate.

The function of the expansion device 6 is to change the high pressure / normal temperature coolant liquid to a low temperature / low pressure coolant liquid. The coolant will evaporate or boil as the pressure drops, and indeed the expansion device 6 may employ a capillary tube, a thermal expansion valve, an electronic expansion valve or other normal expansion device. The function of the evaporator 7 continues to exert the cooling effect of the cooling device by absorbing the ambient heat in the evaporator 7 as a place where the coolant liquid evaporates or vaporizes.
An important aspect of designing the maximum cooling is that the liquid coolant continues to evaporate the coolant liquid completely in the evaporator 7 pipeline and in the range of up to 5 ° C superheat.
As a result, when the cooling steam leaves the evaporator 7, the temperature is set between the operating temperature of the thermostatic tank or the thermostatic tank 9 where temperature control is required and the environmental temperature of the place where the apparatus is installed.

The pressure regulating valve 4 is a special automatic control device that maintains the heat radiation temperature of the compressor 2. The pressure regulating valve 4 is not an essential component for a conventional cooling device, but is a specific component particularly for the present invention.
The pressure regulating valve 4 tends to open to allow more cooling flow as the discharge pressure increases. That is, when the pressure reaches the set value, the pressure regulating valve 4 starts opening. The operation of the pressure regulating valve 4 depends on the discharge pressure of the compressor 2 and is not related to the outlet of the pressure regulating valve 4 or the pressure in the condenser 5.

In this case, the influence on the discharge pressure resulting from the operation of the electronic expansion valve 11 can be minimized. As a result, a stable discharge pressure and hot air bypass temperature can be guaranteed. Even if the electronic expansion valve 11 continues to open, a constant discharge pressure ensures a stable heat source and ensures a sufficient heating temperature and highly accurate temperature control.
That is, without the pressure regulating valve 4, the cooling device cannot achieve the expected energy regulation. When the temperature rises in the constant temperature tank or the constant temperature bath 9 that requires temperature control, the electronic expansion valve 11 is closed and normal cooling is performed. When the temperature drops in the constant temperature tank or the constant temperature bath 9 requiring temperature control, the electronic expansion valve 11 opens again.
Without the pressure regulating valve 4, the discharge pressure gradually decreases due to the opened electronic expansion valve 11 and the heating during processing. The electronic expansion valve 11 is kept open for heating, but the heating temperature is not sufficiently high, and the heating energy is limited. At the same time, cooling is still possible via the normal function of the throttle device 6 such as a capillary tube.

  The thermostat tank or thermostat 9 is the most popular component for cooling devices in climate and environmental test equipment. In order to meet the requirements of the temperature and operating conditions of climate and environmental test equipment, the thermostatic tank or thermostatic bath 9 is usually composed of an internal chamber or bath tank, an enclosure and an insulating material. For easy operation and access, the thermostat or thermostat 9 also includes a door or cover that can be opened or closed. If the operating temperature is well above ambient temperature, the door or cover must also be kept warm with a sealing gasket or cushioning material.

  The temperature sensor 10 is used to detect the temperature of air and liquid in the thermostatic tank or the thermostatic bath 9. The temperature sensor 10 and the circulation fan or pump 8 are important and affect the authenticity of the detected temperature in various ways, and consequently the operation of the electronic expansion valve 11 for hot air bypassing.

The electronic expansion valve 11 and the hot air valve drive control panel 13 are components that are specific to the preferred embodiment of the present invention. The electronic expansion valve 11 is an automatic device having an opening, a closing and an opening degree that are adjusted in accordance with and in proportion to voltage or current input. The hot air valve drive control panel 13 receives a drive signal such as voltage or current from the controller 1 and directly adjusts the opening, closing and opening degree of the electronic expansion valve 11. The output of the hot air valve drive control panel 13 must be compatible with the drive required by the electronic expansion valve 11. Normally, when the hot air valve drive control panel 13 receives an input voltage of 0 V or a current of 4 mA, the electronic expansion valve 11 must be completely closed. On the other hand, when the hot air valve drive control panel 13 receives an input voltage of 5 V or a current of 20 mA, the electronic expansion valve 11 must be completely opened. When the input signal has a range between the maximum value and the minimum value, the position or opening degree for the electronic expansion valve 11 corresponds to the input level. Therefore, when the detected temperature is higher and the control 1 reduces the output valve opening signal, the opening degree of the electronic expansion valve 11 becomes smaller as the output voltage or current of the electronic expansion valve 11 becomes smaller. As a result, the cooling amount increases and the temperature gradually decreases. Conversely, when the detected temperature is low and the output voltage or current of the controller 1 is larger, the opening degree of the electronic expansion valve 11 is larger when the control 1 increases the signal of the valve opening of the output. As a result, the cooling amount decreases and the temperature gradually increases. When the detected temperature is stable, the output voltage or current of the controller 1 remains unchanged, and the opening degree of the electronic expansion valve 11 is kept constant. One end of the electronic expansion valve 11 is provided in the pipeline between the discharge port of the compressor and the front end of the pressure regulating valve, and the other end is provided in the pipeline between the rear portion of the expansion device and the inlet of the evaporator. Provided. The thermal expansion valve is used for the control of the evaporation temperature and the self-adjustment of the superheat degree. Using a temperature close to the set value, the controller sends a signal to control the electronic expansion valve 11 and directly bypasses the high-temperature cooling steam from the discharge port of the compressor 2 with a certain degree of opening. The cooling flow to the condenser is limited by the pressure regulating valve 4, and as a result, the cooling amount of the cooling device is suppressed. In this way, the heating and cooling amounts are effectively controlled, and the temperature is maintained at a set value with high accuracy. The electronic expansion valve 11 for the above-mentioned purpose can be a flow proportional valve type. Solenoid valves can also be used when cost reduction is more important than temperature precision control and cooling.

Claims (7)

A cooling amount control device comprising a cooling device having a compressor, an evaporator, and a condenser connected in series in a pipeline,
A controller,
A pressure regulating valve provided between the outlet of the compressor of the cooling device and the inlet of the condenser;
A throttling device provided between the outlet of the condenser of the cooling device and the inlet of the evaporator;
A control panel for driving hot air valves;
One end is provided in the pipeline between the outlet of the compressor and the front end of the compression regulating valve, and the other end is provided in the pipeline between the rear portion of the expansion device and the inlet of the evaporator, for driving the hot air valve And a hot air valve connected to the controller via a control panel. The cooling amount control device according to claim 1, wherein the expansion device is a thermal expansion valve. The cooling amount control device according to claim 1, wherein the throttle device is a capillary tube.   The cooling amount control device according to claim 1, wherein the throttle device is an electronic expansion valve.   2. The cooling amount control device according to claim 1, wherein the hot air valve is an electrically operated valve that opens and closes continuously or an electromagnetic valve that opens and closes intermittently. A test apparatus comprising the cooling amount control apparatus according to claim 1,
The test apparatus includes a cooling amount control device, a thermostatic tank or a thermostatic bath,
The cooling amount control device includes a cooling amount device including a compressor, an evaporator, and a condenser connected in series in a pipeline.
The cooling amount control device includes:
A controller,
A pressure regulating valve provided between the outlet of the compressor of the cooling device and the inlet of the condenser;
A throttling device provided between the outlet of the condenser of the cooling device and the inlet of the evaporator;
A control panel for driving hot air valves;
One end is provided in the pipeline between the outlet of the compressor and the front end of the compression regulating valve, and the other end is provided in the pipeline between the rear portion of the expansion device and the inlet of the evaporator, for driving the hot air valve A hot air valve connected to the controller via the control panel;
Further comprising
The evaporator is provided in a constant temperature tank or a constant temperature bath, and a temperature sensor provided in the constant temperature tank or the constant temperature bath is connected to the controller. A cooling amount control method for controlling a cooling amount using the test apparatus according to claim 6,
First, a pressure regulating valve is provided between the compressor and the condenser of the conventional cooling device,
Next, one end of the hot air valve is provided in the pipeline between the outlet of the compressor and the front end of the compression regulating valve, and the other end is provided in the pipeline between the rear portion of the expansion device and the inlet of the evaporator. ,
The hot air valve is connected to the controller via a hot air valve drive control panel, and a throttle device is provided between the condenser outlet of the cooling device and the inlet of the evaporator,
The pressure regulating valve ensures stable discharge pressure and hot air temperature, and prevents the opening and closing of the hot air valve from affecting the discharge pressure,
The throttle device self-adjusts the evaporation temperature and superheat,
The hot air valve directly discharges high-temperature steam at the outlet of the compressor at a specified opening,
By limiting the coolant flowing into the condenser with a compression regulating valve, and reducing the export of system cooling,
A cooling amount control method capable of performing effective heating and cooling amount control and maintaining the temperature at a set value with high accuracy.

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