Energy-saving segmented refrigeration system suitable for ultra-large type high and low temperature test chamber and control method

Abstract

The invention belongs to the technical field of refrigeration, and particularly relates to an energy-saving segmented refrigeration system suitable for an ultra-large type high and low temperature test chamber and a control method. Comprising a high-temperature-stage compressor, a condenser, an auxiliary stop valve, a main stop valve, a high-temperature-stage auxiliary expansion valve, a high-temperature-stage main expansion valve, a low-temperature-stage compressor, an evaporative condenser and a low-temperature-stage expansion valve which are arranged in a refrigeration area, and a circulating fan, a high-temperature-stage evaporator and a low-temperature-stage evaporator which are arranged in a test area, the high-temperature compressor, the condenser, the auxiliary stop valve, the high-temperature auxiliary expansion valve and the high-temperature evaporator are sequentially connected in series to form a loop, and the high-temperature compressor, the condenser, the main stop valve, the high-temperature main expansion valve and the evaporative condenser are sequentially connected in series to form a loop. And the low-temperature-stage compressor, the evaporative condenser, the low-temperature-stage expansion valve and the low-temperature-stage evaporator are sequentially connected in series to form a loop. Through the dehumidification program, the main cooling program and the constant temperature program, the requirements for dehumidification, pre-cooling and energy consumption reduction are met.

Description

Technical Field

[0001] The present invention belongs to the field of refrigeration technology, and in particular relates to an energy-saving segmented refrigeration system and a control method suitable for an ultra-large high and low temperature test chamber. Background Art

[0002] With the continuous advancement of science and technology, high and low temperature test chambers are increasingly used in the fields of material testing, electronic product verification, aerospace and automotive industries. The working principle of the high and low temperature test chamber is to use the low temperature refrigerant in the cascade refrigeration system to reduce the ambient temperature to below -70℃, and the high temperature refrigeration system is only used as the cold source of the low temperature refrigeration system.

[0003] However, when the environment in the test chamber is cooling down, a lot of frost will form on the evaporator, affecting the performance of the unit. At the same time, when the unit is set at around 0°C or is in the insulation stage, the system requires less cooling capacity. At this time, a large amount of cooling capacity will be wasted if a low-temperature refrigeration system is used, resulting in a waste of resources. Summary of the invention

[0004] In order to solve the deficiencies in the prior art, the present invention provides an energy-saving segmented refrigeration system and a control method suitable for an ultra-large high and low temperature test chamber.

[0005] The present invention provides the following technical solutions:

[0006] An energy-saving segmented refrigeration system suitable for an ultra-large high and low temperature test chamber, the ultra-large high and low temperature test chamber comprising a chamber body and a high and low temperature environment test energy-saving segmented refrigeration system, the chamber body comprising a refrigeration zone, a test zone and a control zone, the high and low temperature environment test energy-saving segmented refrigeration system comprising a high-temperature refrigeration system and a low-temperature refrigeration system, the high and low temperature environment test energy-saving segmented refrigeration system comprising a high-temperature compressor, a condenser, a secondary stop valve, a main stop valve, a high-temperature secondary expansion valve, a high-temperature main expansion valve, a low-temperature compressor, an evaporative condenser and a low-temperature expansion valve arranged in the refrigeration zone, and a circulating fan, a high-temperature evaporator and a low-temperature evaporator arranged in the test zone, wherein:

[0007] The high-temperature refrigeration system comprises two circuits: a circuit in which the high-temperature compressor, condenser, auxiliary stop valve, high-temperature auxiliary expansion valve and high-temperature evaporator are connected in series in sequence, and a circuit in which the high-temperature compressor, condenser, main stop valve, high-temperature main expansion valve and evaporative condenser are connected in series in sequence;

[0008] The low-temperature refrigeration system comprises a circuit in which the low-temperature compressor, the evaporative condenser, the low-temperature expansion valve and the low-temperature evaporator are sequentially connected in series.

[0009] A control method, which adopts the above energy-saving segmented refrigeration system suitable for ultra-large high and low temperature test chamber, has the following specific steps:

[0010] L1. Start the dehumidification program, only start the high-temperature compressor, and at the same time, according to the dew point temperature detected by the temperature detection device in the test area, the system partially opens the auxiliary stop valve, closes the main stop valve, and opens the drain valve. The high-pressure gaseous refrigerant in the system is cooled to liquid through the condenser, and then throttled through the high-temperature auxiliary expansion valve to become low-pressure liquid refrigerant, and then enters the high-temperature evaporator, so that the surface temperature of the high-temperature evaporator is lower than the dew point temperature of the air in the test area at this time, so that the water vapor in the test area is condensed on the high-temperature evaporator, and then blown to the floor of the test area by the circulating fan and discharged through the drain valve;

[0011] L2, start the main cooling program, including the following steps:

[0012] (1) When the dehumidification program reaches the set running time, the auxiliary stop valve is fully opened, the circulation fan is turned on, and the drain valve is closed. At this time, the high-temperature refrigeration system is fully operational to cool the test area;

[0013] (2) When the capacity limit of the high-temperature refrigeration system is reached and the temperature in the test area no longer drops, the secondary stop valve is closed, and the main stop valve and the low-temperature compressor are opened. At this time, the high-temperature refrigeration system and the low-temperature refrigeration system are operated simultaneously. The high-temperature liquid refrigerant is throttled by the high-temperature main expansion valve, and the low-temperature refrigerant in the evaporative condenser is cooled to liquid. The liquid low-temperature refrigerant is throttled by the low-temperature expansion valve and enters the low-temperature evaporator to vaporize and absorb the heat in the test area until the temperature of the test area drops to the set value;

[0014] L3. Start the constant temperature program. When the system reaches the temperature setting value, turn off the low-temperature compressor and the main stop valve, and only open the auxiliary stop valve. Adjust the opening of the auxiliary stop valve in real time according to the temperature feedback in the test area to ensure the accuracy of the temperature in the test area.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] 1. Dehumidification function: In the initial stage of system startup, the high-temperature refrigeration system can remove most of the water vapor inside the test area through the condensation effect of the evaporator to avoid frost on the evaporator surface affecting the refrigeration performance.

[0017] 2. Pre-cooling function: during conventional cooling, the high-temperature refrigeration system is first used to reduce the temperature of the test area from room temperature to the working limit of the high-temperature level, and then the low-temperature refrigeration system is started for deep cooling.

[0018] 3. Reduce energy consumption. When the test chamber reaches the operating temperature and enters the temperature maintenance stage, only the high-temperature refrigeration system of the refrigeration system is in operation to compensate for the loss caused by the dissipation of cold air in the cabin. This process reduces the operating time of the low-temperature compressor, which helps to increase its service life while reducing operating energy consumption, thus achieving energy-saving effects.

[0019] 4. When the system has a low demand for cooling capacity, the high-temperature refrigeration system can operate independently, thereby enhancing the control accuracy of the overall system. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a single system principle diagram of the present invention;

[0021] Figure 2 It is a schematic diagram of the cabin of the present invention;

[0022] Figure 3 It is the multi-system principle diagram of the present invention.

[0023] Among them, 1-refrigeration zone, 101-high temperature compressor, 102-condenser, 103-auxiliary stop valve, 104-main stop valve, 105-high temperature auxiliary expansion valve, 106-high temperature main expansion valve, 107-low temperature compressor, 108-evaporative condenser, 109-low temperature expansion valve, 2-test area, 201-circulation fan, 202-high temperature evaporator, 203-low temperature evaporator, 3-control area, 4-drain valve, 5-high temperature evaporator I, 6-low temperature evaporator I, 7-refrigeration unit. DETAILED DESCRIPTION

[0024] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0025] like Figure 1-Figure 3 As shown, an energy-saving segmented refrigeration system suitable for an ultra-large high and low temperature test chamber, the ultra-large high and low temperature test chamber includes a chamber body and a high and low temperature environment test energy-saving segmented refrigeration system, the chamber body includes a refrigeration zone 1, a test zone 2 and a control zone 3, the high and low temperature environment test energy-saving segmented refrigeration system includes a high-temperature refrigeration system and a low-temperature refrigeration system, the high and low temperature environment test energy-saving segmented refrigeration system includes a high-temperature compressor 101, a condenser 102, a secondary stop valve 103, a main stop valve 104, a high-temperature secondary expansion valve 105, a high-temperature main expansion valve 106, a low-temperature compressor 107, an evaporative condenser 108 and a low-temperature expansion valve 109 arranged in the refrigeration zone 1, and a circulating fan 201, a high-temperature evaporator 202 and a low-temperature evaporator 203 arranged in the test zone 2, wherein:

[0026] The high temperature refrigeration system comprises two circuits: a circuit in which the high temperature compressor 101, the condenser 102, the secondary stop valve 103, the high temperature secondary expansion valve 105 and the high temperature evaporator 202 are connected in series in sequence, and a circuit in which the high temperature compressor 101, the condenser 102, the main stop valve 104, the high temperature main expansion valve 106 and the evaporative condenser 108 are connected in series in sequence;

[0027] The low-temperature refrigeration system includes a circuit in which the low-temperature compressor 107, the evaporative condenser 108, the low-temperature expansion valve 109 and the low-temperature evaporator 203 are connected in series in sequence.

[0028] The energy-saving segmented refrigeration system suitable for the ultra-large high and low temperature test chamber has a condenser 102 that is air-cooled or water-cooled.

[0029] The energy-saving segmented refrigeration system suitable for an ultra-large high and low temperature test chamber has a drain valve 4 at the bottom of the test area 2 .

[0030] The cooling form of the condenser 102 can be air cooling or water cooling according to the cooling capacity of the system.

[0031] The drain valve 4 is a one-way valve to prevent backflow. The drain valve 4 is connected to a pipeline to drain water to the outside of the cabin.

[0032] Embodiment 1

[0033] A control method, which adopts the above energy-saving segmented refrigeration system suitable for an ultra-large high and low temperature test chamber, comprises the following steps:

[0034] 1. Run the dehumidification program. The system only starts the high-temperature compressor 101. At the same time, the system partially opens the auxiliary stop valve 103, closes the main stop valve 104, and opens the drain valve 4 according to the dew point temperature detected by the temperature detection device in the test area 2. The high-pressure gaseous refrigerant inside the system is cooled to liquid through the condenser 102, and then throttled through the high-temperature auxiliary expansion valve 105 to become a low-pressure liquid refrigerant, and then enters the high-temperature evaporator 202, so that the surface temperature of the high-temperature evaporator 202 is lower than the dew point temperature of the air in the test area 2 at this time, so that the water vapor in the test area 2 is condensed on the high-temperature evaporator 202, and then blown to the floor of the test area by the circulating fan 201 and discharged through the drain valve 4.

[0035] 2. Run the main cooling program, which is divided into two stages. In stage one, when the dehumidification program reaches the set running time, the auxiliary stop valve 103 is fully opened, the circulating fan 201 is turned on, and the drain valve 4 is closed. At this time, the high-temperature refrigeration system is fully operated to cool the test area 2. When the capacity upper limit of the high-temperature refrigeration system is reached, the temperature in the test area 2 no longer drops, and the system starts the second stage cooling program. Close the auxiliary stop valve 103, open the main stop valve 104 and the low-temperature compressor 107, and the high-temperature refrigeration system and the low-temperature refrigeration system are running at the same time. After the high-temperature liquid refrigerant is throttled by the high-temperature main expansion valve 106, the low-temperature refrigerant in the evaporative condenser 108 is cooled to liquid, and the liquid low-temperature refrigerant enters the low-temperature evaporator 203 after throttling through the low-temperature expansion valve 109 to vaporize and absorb the heat in the test area 2 until the temperature of the test area 2 drops to the set value.

[0036] 3. Run the constant temperature program. When the system reaches the temperature setting value, turn off the low-temperature compressor 107 and the main stop valve 104, the low-temperature refrigeration system is turned off to prevent the temperature from further dropping, and only open the auxiliary stop valve 103 to maintain the temperature in the test area 2 using the cold energy generated by the high-temperature refrigeration system. At the same time, the control area will adjust the opening of the auxiliary stop valve 103 in real time according to the temperature feedback in the test area 2, so as to ensure the accuracy of the temperature in the test area 2.

[0037] In this way, the dehumidification, pre-cooling and energy consumption reduction requirements of the test chamber are achieved.

[0038] Embodiment 2

[0039] The test area inside the super large test chamber has multiple sets of high temperature evaporators Ⅰ5 and low temperature evaporators Ⅰ6. Each set of evaporators is connected in parallel with the refrigeration unit 7 in the refrigeration area to form a complete system. Its internal control logic is similar to that of the first embodiment. The unit can be manually set in combination. When a refrigeration unit fails, the system will prompt the unit failure information. After the combination is manually set, the program will automatically call the combined unit to run and start and stop.

[0040] In the refrigeration system, in order to prevent the problem of frost on the compressor head due to long-term low temperature and constant temperature, the system can set a constant temperature bypass, which will automatically open when the compressor return temperature is too low to ensure that the compressor head is not frosted, thereby extending the service life of the compressor.

[0041] In a traditional cascade refrigeration system, the function of the high-temperature refrigeration system is only to provide cooling capacity for the condensation of the low-temperature refrigerant. For this reason, the high-temperature refrigeration system and the low-temperature refrigeration system need to be started and operated simultaneously each time. In the present invention, when the system has a small demand for cooling capacity, the high-temperature refrigeration system can operate independently, thereby enhancing the control accuracy of the overall system.

[0042] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. The above is only a preferred implementation of the present invention. It should be pointed out that due to the limitations of textual expression and the objective existence of infinite specific structures, ordinary technicians in this technical field can make several improvements, modifications or changes without departing from the principles of the present invention, and can also combine the above technical features in an appropriate manner; these improvements, modifications, changes or combinations, or the direct application of the concept and technical solution of the present invention to other occasions without improvement, should be regarded as the protection scope of the present invention.

Claims

1. An energy-saving segmented refrigeration system suitable for an ultra-large high and low temperature test chamber, characterized in that: The ultra-large high and low temperature test chamber comprises a chamber body and a high and low temperature environment test energy-saving segmented refrigeration system, wherein the chamber body comprises a refrigeration zone (1), a test zone (2) and a control zone (3), wherein the high and low temperature environment test energy-saving segmented refrigeration system comprises a high temperature refrigeration system and a low temperature refrigeration system, wherein the high and low temperature environment test energy-saving segmented refrigeration system comprises a high temperature compressor (101), a condenser (102), a secondary stop valve (103), a main stop valve (104), a high temperature secondary expansion valve (105), a high temperature main expansion valve (106), a low temperature compressor (107), an evaporative condenser (108) and a low temperature expansion valve (109) arranged in the refrigeration zone (1), and a circulation fan (201), a high temperature evaporator (202) and a low temperature evaporator (203) arranged in the test zone (2), wherein: The high-temperature refrigeration system comprises two circuits: a circuit in which the high-temperature compressor (101), the condenser (102), the auxiliary stop valve (103), the high-temperature auxiliary expansion valve (105) and the high-temperature evaporator (202) are sequentially connected in series, and a circuit in which the high-temperature compressor (101), the condenser (102), the main stop valve (104), the high-temperature main expansion valve (106) and the evaporative condenser (108) are sequentially connected in series; The low-temperature refrigeration system comprises a circuit in which the low-temperature compressor (107), the evaporative condenser (108), the low-temperature expansion valve (109) and the low-temperature evaporator (203) are connected in series.

2. The energy-saving segmented refrigeration system suitable for an ultra-large high and low temperature test chamber according to claim 1 is characterized in that: The condenser (102) is an air-cooled or water-cooled condenser.

3. The energy-saving segmented refrigeration system suitable for an ultra-large high and low temperature test chamber according to claim 1 is characterized in that: A drainage valve (4) is provided at the bottom of the test area (2).

4. A control method, characterized in that: The control method is performed using a refrigeration system as described in any one of claims 1 to 3, comprising the following steps: L1. Start the dehumidification program, only start the high-temperature compressor (101), and at the same time, according to the dew point temperature detected by the temperature detection device in the test area (2), the system partially opens the auxiliary stop valve (103), closes the main stop valve (104), and opens the drain valve (4). The high-pressure gaseous refrigerant in the system passes through the condenser (102) and is cooled to liquid state, and then passes through the high-temperature auxiliary expansion valve (105) to become low-pressure liquid refrigerant, and then enters the high-temperature evaporator (202), so that the surface temperature of the high-temperature evaporator (202) is lower than the dew point temperature of the air in the test area (2) at this time, so that the water vapor in the test area (2) is condensed on the high-temperature evaporator (202), and then blown by the circulation fan (201) to the floor of the test area and discharged through the drain valve (4); L2, start the main cooling program, including the following steps: (1) When the dehumidification program reaches the set running time, the auxiliary stop valve (103) is fully opened, the circulation fan (201) is turned on, and the drain valve (4) is closed. At this time, the high-temperature refrigeration system is fully operated to cool the test area (2); (2) When the capacity upper limit of the high-temperature refrigeration system is reached and the temperature in the test area (2) no longer decreases, the secondary stop valve (103) is closed, and the main stop valve (104) and the low-temperature compressor (107) are opened. At this time, the high-temperature refrigeration system and the low-temperature refrigeration system are operated simultaneously. The high-temperature liquid refrigerant is throttled by the high-temperature main expansion valve (106), and the low-temperature refrigerant in the evaporative condenser (108) is cooled to liquid. The liquid low-temperature refrigerant is throttled by the low-temperature expansion valve (109) and enters the low-temperature evaporator (203) to vaporize and absorb the heat in the test area (2) until the temperature of the test area (2) drops to the set value; L3. Start the constant temperature program. When the system reaches the temperature setting value, turn off the low temperature compressor (107) and the main stop valve (104), and only open the auxiliary stop valve (103). The opening of the auxiliary stop valve (103) is adjusted in real time according to the temperature feedback in the test area (2), so as to ensure the accuracy of the temperature in the test area (2).

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