A control method for refrigeration / heat pipe composite cabinet air conditioner

Abstract

The present invention relates to the technical field of cabinet temperature control equipment in the communication, electric power, and industrial control industries, and specifically to a refrigeration / heat pipe composite cabinet air conditioner control method, including a cabinet shell, a condenser, an external circulation fan, a compressor, an evaporator, an internal circulation fan, and a throttling variable mechanism are arranged inside the cabinet shell, and the throttling variable mechanism includes a three-way valve and an electronic expansion valve. The present invention realizes the automatic operation of the heat pipe system and the vapor compression refrigeration system according to different working conditions through an automatic control system, so that the system always operates in the energy-saving mode under its different working conditions, and ensures that the temperature in the cabinet is within a reasonable range, while reducing the operating cost of the system, reducing energy consumption, and improving the comprehensive energy efficiency ratio throughout the year. In addition, the composite cabinet air conditioner has a reasonable structural design, simple piping, and saves material costs; it has intelligent automatic control operation and convenient operation and maintenance.

Description

Technical Field

[0001] The present invention relates to cabinet temperature control equipment in the communication, electric power and industrial control industries, and more particularly to a refrigeration / heat pipe composite cabinet air conditioner control method. Background Art

[0002] Cabinet air conditioners are widely used in outdoor communication cabinets, base stations, battery cabinets, charging piles, industrial electrical control cabinets and other industries. At present, the cabinet air conditioners used in domestic and foreign industries are mainly composed of cabinet shells, compressors, internal circulation fans, external circulation fans, condensers, evaporators, middle partitions, refrigeration system connection pipes and control parts. Its working principle: After the air conditioner is powered on, the low-pressure vapor of the refrigerant in the refrigeration system is sucked in by the compressor and compressed into high-pressure vapor and then discharged to the condenser. At the same time, the air sucked in by the fan outside the cabinet flows through the condenser, taking away the heat released by the refrigerant, and condensing the high-pressure refrigerant vapor into high-pressure liquid. The high-pressure liquid is sprayed into the evaporator after passing through the throttling device, and evaporates at the corresponding low pressure, absorbing the surrounding heat. At the same time, the fan inside the cabinet allows the air to continuously pass through the fins of the evaporator for heat exchange, and sends the air that becomes cold after heat release to the cabinet. In this way, the air in the cabinet circulates continuously to achieve the purpose of lowering the temperature.

[0003] Since the sensible heat load ratio of the computer room and base station is large, and the cabinet air conditioner is a direct evaporative air conditioning system that operates for cooling throughout the year, even when the external ambient temperature is very low, the compression refrigeration system still needs to continue to operate to cool the computer room, resulting in high energy consumption throughout the year, high operating costs, large start-stop losses of the refrigeration system, loss of machine life, and easy failure. Therefore, if the indoor and outdoor temperature difference can be used to provide cooling (heat dissipation) to the indoor side at a low cost, the annual energy consumption and operating cost of the air conditioning system will be greatly reduced, and the system energy efficiency will be improved. The composite air conditioner using heat pipe technology is a method of using outdoor low-temperature air to provide cooling to the indoor side. However, the existing refrigeration and heat pipe composite air conditioners generally have complex system designs, many copper pipe branches, and most products require two sets of independent pipes and heat exchangers for refrigeration and heat pipes, with high material costs. Therefore, how to save materials while achieving the purpose of using outdoor low-temperature air to provide cooling to the indoor side and improve the energy efficiency of air conditioners throughout the year is a technical problem that technicians in this field currently need to solve. Summary of the invention

[0004] The purpose of the present invention is to solve the following problems existing in the prior art: how to use the same set of heat exchanger and pipeline structure system to efficiently utilize the outdoor natural cooling source while saving materials, reducing energy consumption and saving energy.

[0005] In order to solve the problems existing in the prior art, the present invention provides a refrigeration / heat pipe composite cabinet air conditioner control method, including a cabinet shell, a condenser, an external circulation fan, a compressor, an evaporator, an internal circulation fan and a throttling variable mechanism are arranged inside the cabinet shell, and the throttling variable mechanism includes a three-way valve and an electronic expansion valve, the inlet of the three-way valve is connected to the outlet of the condenser through a pipeline, one outlet of the three-way valve is connected in series to the inlet of the evaporator by the electronic expansion valve, and the other outlet of the three-way valve is directly bypassed to the inlet of the evaporator through a pipeline.

[0006] Preferably, a refrigeration system connecting pipeline, a controller and a four-way valve are arranged inside the cabinet shell, and the refrigeration system connecting pipeline is respectively connected to the exhaust port of the compressor, the inlet of the condenser, the outlet of the evaporator and the suction port of the compressor through the four-way valve.

[0007] Preferably, the outlet of the condenser and the inlet of the evaporator are connected via a throttling variable mechanism pipeline.

[0008] Preferably, the four-way valve and the exhaust port of the compressor are connected through an oil separator pipeline, and the oil return port of the oil separator and the compressor are connected through an oil return capillary tube.

[0009] Preferably, the four-way valve and the air intake of the compressor are connected via a gas-liquid separator pipeline.

[0010] Preferably, the variable throttling mechanism may also be a special valve component such as a two-stage electronic expansion valve, a precision electric ball valve with adjustable opening, or other system components such as an electric ball valve and an electronic expansion valve connected in an equivalent form.

[0011] Preferably, the evaporator is arranged at the bottom of the cabinet shell, and its position height is lower than the position height of the condenser and the throttling variable mechanism.

[0012] Preferably, the specific control method is as follows:

[0013] After the composite cabinet air conditioner unit receives the start command and completes the self-test, the sensor detects the cabinet temperature Tin and the cabinet external environment temperature Tout, and the controller calculates the cabinet internal and external environment temperature difference ΔTa = Tin-Tout.

[0014] When the cabinet temperature Tin ≤ the cabinet set temperature (target temperature) Ts (such as 35°C), the unit is on standby.

[0015] When the temperature inside the cabinet Tin> the set temperature inside the cabinet Ts, select the operation mode according to the temperature difference ΔTa between the inside and outside of the cabinet:

[0016] If the temperature difference between the inside and outside of the cabinet ΔTa satisfies ΔTa>ΔTmin (such as 20℃), the unit will operate the heat pipe cooling mode to take into account both energy saving and cabinet cooling needs, until the temperature difference between the inside and outside of the cabinet changes to meet ΔTa≤ΔTmin, and the heat pipe cooling mode cannot meet the cabinet cooling needs. At this time, the unit switches to the air conditioning cooling mode, the compressor starts working, the throttling mechanism throttles and reduces the pressure, and quickly reduces the air outlet temperature in the cabinet, so that the heating load in the cabinet can work reliably.

[0017] After the unit runs in air conditioning cooling mode, until the temperature difference between the inside and outside of the cabinet satisfies ΔTa>ΔTmax (such as 30℃), the unit switches to heat pipe cooling mode. At this time, the temperature difference between the inside and outside is sufficient to meet the cabinet cooling requirements.

[0018] In this way, the unit control module intelligently selects the operating mode according to the internal and external ambient temperature difference ΔTa, taking into account energy saving and the temperature requirements of the heating load in the cabinet, until the cabinet temperature Tin ≤ the cabinet set temperature Ts, the unit will be on standby.

[0019] When the unit is running in the air conditioning refrigeration mode, the valve core ball position of the four-way valve is transferred to the following state under the action of the coil excitation: the two paths of the valve core ball are connected to the compressor exhaust port and the condenser inlet through the oil separator, and the other path is connected to the evaporator outlet and the compressor suction port through the gas-liquid separator. The three-way valve closes the bypass branch and connects the branch where the electronic expansion valve is located. The electronic expansion valve opens the throttling function to an appropriate degree according to the superheat. When the compressor is running, the low-pressure vapor of the refrigerant is sucked in by the compressor and compressed into high-pressure vapor and then discharged to the condenser. At the same time, the air sucked in by the external circulation fan flows through the condenser, taking away the heat released by the refrigerant, and condensing the high-pressure refrigerant vapor into high-pressure liquid. The high-pressure liquid is sprayed into the evaporator after throttling and reducing the pressure of the electronic expansion valve, and evaporates at a corresponding low pressure. After absorbing the surrounding heat and heating up, it is sucked in again by the compressor. At the same time, the internal circulation fan allows the air to continuously pass through the fins of the evaporator for heat exchange, and sends the cold air after heat exchange into the cabinet;

[0020] When the unit operates in the heat pipe cooling mode, the valve core ball position of the four-way valve is reset to the following state under the excitation of the coil: the two paths of the valve core ball are connected to the exhaust port and the air intake port of the compressor through the oil separator and the gas-liquid separator respectively, so as to short-circuit them, and the other path is connected to the condenser inlet and the evaporator outlet, so that the condenser and the evaporator form an independent heat pipe natural circulation system. The compressor stops, the three-way valve closes the branch where the electronic expansion valve is located, and opens the bypass branch so that the entire throttling variable mechanism has no throttling and pressure reduction effect, and the local resistance is small, which meets the requirement of the heat pipe natural circulation principle that the refrigerant resistance along the way is small. At this time, the control unit in the evaporator The refrigerant will continuously absorb heat and evaporate. The gaseous refrigerant rises to the condenser, condenses and releases heat to become condensate, and under the action of gravity, it flows back to the evaporator through the fully open throttling variable mechanism without throttling effect, completing a natural circulation of the heat pipe. At the same time, the internal circulation fan makes the air in the cabinet continuously pass through the fins of the evaporator for heat exchange, and sends the cold air after heat exchange into the cabinet; the external circulation fan makes the air outside the cabinet continuously pass through the fins of the condenser to absorb heat, and discharges the hot air after heat exchange to the outside of the cabinet. This cycle is repeated, and the unit is in an effective heat pipe cooling state, transferring the heat in the cabinet to the outside environment through the natural circulation of the heat pipe.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The refrigeration / heat pipe composite cabinet air-conditioning system and its control method are provided with a four-way valve, a condenser, an external circulation fan, a throttling variable mechanism, a three-way valve, an electronic expansion valve, a compressor, an evaporator and an internal circulation fan. Through the above design, the device can realize the separate operation of the heat pipe system and the vapor compression refrigeration system according to different working conditions through the automatic control system, so that the system always operates in the energy-saving mode under its different working conditions, ensuring that the temperature in the cabinet is within a reasonable range, while reducing the operating cost of the system, reducing energy consumption, and improving the overall energy efficiency ratio throughout the year. In addition, the composite cabinet air-conditioning has a reasonable structural design, simple piping, and saves material costs; it has intelligent automatic control operation and convenient operation and maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of the air conditioning refrigeration mode of the present invention;

[0024] Figure 2 This is a schematic diagram of the heat pipe heat dissipation mode of the present invention;

[0025] Figure 3 This is a schematic diagram of a first alternative form of the preferred throttling mechanism of the present invention;

[0026] Figure 4 This is a schematic diagram of a second alternative form of the preferred throttling mechanism of the present invention;

[0027] Figure 5 It is a schematic flow chart of the control method of the present invention.

[0028] In the figure: 1. Four-way valve; 2. Condenser; 3. External circulation fan; 4. Variable throttling mechanism; 5. Three-way valve; 6. Electronic expansion valve; 7. Compressor; 8. Evaporator; 9. Internal circulation fan; 10. Oil separator; 11. Oil return capillary; 12. Gas-liquid separator. (The arrows in the figure represent the flow direction of the refrigerant) DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] Embodiment 1

[0031] like Figure 1-5 As shown in the figure, it is assembled from the following parts:

[0032]

[0033]

[0034] Assembly instructions: install the condenser 2, external circulation fan 3, throttling variable mechanism 4, three-way valve 5, electronic expansion valve 6, compressor 7, evaporator 8 and internal circulation fan 9 inside the cabinet shell, and then install the refrigeration system connecting pipeline, controller and four-way valve 1 inside the cabinet shell, connect the refrigeration system connecting pipeline to the exhaust port of the compressor 7, the inlet of the condenser 2, the outlet of the evaporator 8 and the air intake of the compressor 7 through the four-way valve 1, and then connect the inlet of the three-way valve 5 to the outlet of the condenser 2 through the pipeline, one outlet of the three-way valve 5 is connected in series to the inlet of the evaporator 8 by the electronic expansion valve 6, and the other outlet of the three-way valve 5 is directly bypassed to the inlet of the evaporator 8 through the pipeline.

[0035] Embodiment 2

[0036] like Figure 1-5 As shown in the figure, it is assembled from the following parts:

[0037]

[0038]

[0039] Assembly instructions: install the condenser 2, external circulation fan 3, throttling variable mechanism 4, compressor 7, evaporator 8, internal circulation fan 9, oil separator 10 and gas-liquid separator 12 inside the cabinet shell, and then install the refrigeration system connecting pipeline, controller and four-way valve 1 inside the cabinet shell, connect the refrigeration system connecting pipeline to the outlet of the oil separator 10, the inlet of the condenser 2, the outlet of the evaporator 8 and the inlet of the gas-liquid separator 12 through the four-way valve 1, the outlet of the oil separator 10 and the exhaust port of the compressor 7 are connected through a pipeline, the oil return port of the oil separator 10 and the compressor 7 are connected through the oil return capillary 11, the outlet of the gas-liquid separator 12 and the air intake port of the compressor 7 are connected through a pipeline, and then the outlet of the condenser 2 and the inlet of the evaporator 8 are connected through the throttling variable mechanism 4 pipeline.

[0040] When the unit switches from air conditioning refrigeration mode to heat pipe cooling mode, the action sequence of each component is as follows: the throttling variable mechanism 4 is fully closed, the unit refrigerant is recovered to the condenser 2 under the drive of the compressor 7, and after a period of time t, the valve core ball position of the four-way valve 1 is switched from the air conditioning refrigeration state to the heat pipe cooling state, the compressor 7 stops, the throttling variable mechanism 4 is fully opened, and the internal circulation fan 9 and the external circulation fan 3 automatically adjust the speed according to the heat pipe cooling load program. The above-mentioned refrigerant recovery time t is intelligently controlled by the control module according to the amount of refrigerant required by the heat load of the heat pipe cooling mode.

[0041] When the unit switches from the heat pipe cooling mode to the air conditioning refrigeration mode, the action sequence of each component is as follows: the valve core ball position of the four-way valve 1 switches from the heat pipe cooling state to the air conditioning refrigeration state, the throttling variable mechanism 4 is reset and opened to the initial opening according to the air conditioning refrigeration logic, the internal circulation fan 9 and the external circulation fan 3 are automatically adjusted by the program according to the heat load, and the compressor 7 is started. Thereafter, the components of the unit operate according to the air conditioning refrigeration logic.

[0042] Figure 3 It is a two-stage electronic expansion valve. In the air conditioning refrigeration mode, this valve is adjusted at a relatively small opening to throttle and reduce the pressure of the refrigerant. In the heat pipe heat dissipation mode, this valve is fully open, with a reasonable diameter and extremely small local resistance, meeting the requirement of the heat pipe natural circulation principle that the refrigerant has a small resistance along the way.

[0043] Figure 4 It is a precision electric ball valve with adjustable opening. In the air conditioning cooling mode, this valve can precisely adjust the refrigerant flow rate through the grooves on the structure at a relatively small opening; in the heat pipe cooling mode, this valve is fully open to meet the requirement of the heat pipe natural circulation principle that the refrigerant has low resistance along the way.

[0044] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. The above embodiments and descriptions are only preferred examples of the present invention and are not intended to limit the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A control method for a refrigeration / heat pipe composite cabinet air conditioner, comprising a cabinet shell, characterized in that: A condenser (2), an external circulation fan (3), a compressor (7), an internal circulation fan (9) and a throttling variable mechanism (4) are arranged inside the cabinet shell. The throttling variable mechanism (4) comprises a three-way valve (5) and an electronic expansion valve (6). The inlet of the three-way valve (5) is connected to the outlet of the condenser (2) through a pipeline. One outlet of the three-way valve (5) is connected in series to the inlet of the evaporator (8) through the electronic expansion valve (6). The other outlet of the three-way valve (5) is directly bypassed to the inlet of the evaporator (8) through a pipeline. The evaporator (8) is arranged at the bottom end of the cabinet shell, and its position height is lower than the position height of the condenser (2) and the throttling variable mechanism (4). A refrigeration system connecting pipeline, a controller and a four-way valve (1) are arranged inside the cabinet shell, and the refrigeration system connecting pipeline is respectively connected to the exhaust port of the compressor (7), the inlet of the condenser (2), the outlet of the evaporator (8) and the air intake port of the compressor (7) through the four-way valve (1); The outlet of the condenser (2) and the inlet of the evaporator (8) are connected via a throttling variable mechanism (4) pipeline; An oil separator (10) is added between the four-way valve (1) and the compressor (7); the exhaust port of the four-way valve (1) and the compressor (7) are connected via a pipeline of the oil separator (10); and the oil return port of the oil separator (10) and the compressor (7) are connected via an oil return capillary (11); A gas-liquid separator (12) is added between the four-way valve (1) and the compressor (7), and the four-way valve (1) and the air intake port of the compressor (7) are connected via a pipeline of the gas-liquid separator (12); The specific control methods are as follows: After the composite cabinet air conditioner unit receives the start command and completes the self-test, it detects the cabinet temperature Tin and the external environment temperature Tout through the sensor, and the controller calculates the internal and external environment temperature difference ΔTa = Tin-Tout; When the cabinet temperature Tin ≤ the cabinet set temperature Ts, Ts is 35℃, the unit is on standby; When the temperature inside the cabinet Tin> the set temperature inside the cabinet Ts, select the operation mode according to the temperature difference ΔTa between the inside and outside of the cabinet: If the temperature difference ΔTa between the inside and outside of the cabinet satisfies ΔTa>ΔTmin, and ΔTmin is 20°C, the unit operates in a heat pipe cooling mode to take into account both energy saving and cabinet cooling requirements, until the temperature difference between the inside and outside of the cabinet satisfies ΔTa≤ΔTmin, and the heat pipe cooling mode cannot meet the cabinet cooling requirement. At this time, the unit switches to an air conditioning cooling mode, the compressor (7) starts working, and the throttling mechanism throttles and reduces the pressure, quickly reducing the air outlet temperature in the cabinet, so that the heating load in the cabinet can work reliably; After the unit runs in the air conditioning cooling mode, until the temperature difference between the inside and outside of the cabinet satisfies ΔTa>ΔTmax, ΔTmax is 30°C, the unit switches to the heat pipe cooling mode. At this time, the temperature difference between the inside and outside is sufficient to meet the cabinet cooling requirements; In this way, the unit control module intelligently selects the operating mode according to the temperature difference ΔTa between the inside and outside of the cabinet, taking into account energy saving and the temperature requirements of the heating load in the cabinet. When the temperature Tin in the cabinet is less than or equal to the set temperature Ts in the cabinet, the unit will be in standby mode. When the unit is operating in the air conditioning refrigeration mode, the valve core ball position of the four-way valve (1) is changed to the following state under the action of the coil excitation: one of the two paths of the valve core ball passes through the oil separator (10) to connect the compressor (7) exhaust port and the condenser (2) inlet, and the other path passes through the gas-liquid separator (12) to connect the evaporator 8 outlet and the compressor (7) suction port. The three-way valve (5) closes the bypass branch and connects the branch where the electronic expansion valve (6) is located. The electronic expansion valve (6) opens the throttling function to an appropriate opening according to the superheat, and the compressor (7) runs, and the low-pressure vapor of the refrigerant is compressed. The compressor (7) sucks in and compresses the refrigerant into high-pressure vapor and then discharges it to the condenser (2). At the same time, the air sucked in by the external circulation fan (3) flows through the condenser (2), takes away the heat released by the refrigerant, and condenses the high-pressure refrigerant vapor into a high-pressure liquid. The high-pressure liquid is throttled and depressurized by the electronic expansion valve (6) and then sprayed into the evaporator (8), where it evaporates at a corresponding low pressure, absorbs the surrounding heat and heats up before being sucked in again by the compressor (7). At the same time, the internal circulation fan (9) causes the air to continuously pass through the fins of the evaporator (8) for heat exchange, and sends the air that has become cold after the heat exchange into the cabinet. When the unit operates in the heat pipe cooling mode, the valve core ball position of the four-way valve (1) is reset to the following state under the action of the coil excitation: one of the two paths of the valve core ball passes through the oil separator (10) and the gas-liquid separator (12) to connect to the exhaust port and the air intake port of the compressor (7) respectively, so that they are short-circuited, and the other path connects to the inlet of the condenser (2) and the outlet of the evaporator (8), so that the condenser (2) and the evaporator (8) form an independent heat pipe natural circulation system, the compressor (7) stops, the three-way valve (5) closes the branch where the electronic expansion valve (6) is located, and the bypass branch is opened so that the entire throttling variable mechanism (4) has no throttling and pressure reduction effect, and the local resistance is small, which meets the requirement of the heat pipe natural circulation principle that the refrigerant resistance along the way is small. At this time The refrigerant in the evaporator (8) will continuously absorb heat and evaporate. The gaseous refrigerant rises to the condenser (2) to condense and release heat to become condensate. Under the action of gravity, it passes through the fully open throttling variable mechanism (4) without throttling effect and flows back to the evaporator (8), completing a heat pipe natural circulation. At the same time, the internal circulation fan (9) causes the air in the cabinet to continuously pass through the fins of the evaporator (8) for heat exchange, and sends the air that has become cold after the heat exchange into the cabinet; the external circulation fan (3) causes the air outside the cabinet to continuously pass through the fins of the condenser (2) for heat absorption, and discharges the air that has become hot after the heat exchange to the outside of the cabinet. This reciprocating process is carried out, and the unit is in an effective heat pipe cooling state, and the heat in the cabinet is transferred to the environment outside the cabinet through the natural circulation of the heat pipe.

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