CN114710932A - Refrigeration/heat pipe composite type cabinet air conditioning system and control method thereof - Google Patents

Abstract

The invention relates to the technical field of cabinet temperature control equipment in the communication, power and industrial control industries, in particular to a refrigeration/heat pipe composite cabinet air conditioning system and a control method thereof. According to the invention, through the automatic control system, the automatic operation of the heat pipe system and the vapor compression refrigeration system is realized according to different working conditions, so that the system always operates in an energy-saving mode under different working conditions, the temperature in the cabinet is ensured to be in a reasonable range, the operation cost of the system is reduced, the energy consumption is reduced, and the annual comprehensive energy efficiency ratio is improved. In addition, the composite cabinet air conditioner has reasonable structural design, simple pipelines and material cost saving; the intelligent automatic control operation is convenient and fast in operation and maintenance.

Description

A refrigeration/heat pipe composite cabinet air-conditioning system and its control method

technical field

The invention relates to cabinet temperature control equipment in communication, electric power and industrial control industries. In particular, it relates to a refrigeration/heat pipe composite type cabinet air conditioning system and a control method thereof.

Background technique

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, cabinet air conditioners used in domestic and foreign industries are mainly composed of cabinet shells, compressors, internal circulation fans, and external circulation fans. , condenser, evaporator, middle partition, refrigeration system connecting pipeline and control part. Its working principle: After the air conditioner is powered on, the low-pressure vapor of the refrigerant in the refrigeration system is inhaled by the compressor and compressed into high-pressure vapor before being discharged to the condenser. At the same time, the air sucked by the fan outside the cabinet flows through the condenser to take away the heat released by the refrigerant. , which condenses the high-pressure refrigerant vapor into a high-pressure liquid. The high-pressure liquid is sprayed into the evaporator after passing through the throttling device, and evaporates under the corresponding low pressure, absorbing the surrounding heat. At the same time, the fan in the cabinet makes the air continuously exchange heat through the fins of the evaporator, and sends the air cooled after the heat release to the cabinet. In this way, the air in the cabinet circulates continuously to achieve the purpose of lowering the temperature.

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 throughout the year, even when the external ambient temperature is very low, it is necessary to continue to operate the compression refrigeration system to cool down the computer room. The annual energy consumption is high, the operating cost is high, the start-stop loss of the refrigeration system is large, the machine life is lost, and it is prone to failure. Therefore, if the indoor and outdoor temperature difference can be used to provide cooling (heat dissipation) for 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 energy efficiency of the system will be improved. A 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 general system design of the existing cooling and heat pipe compound air conditioners is complex, and there are many copper pipe branches. Most of the products require two sets of independent pipes and heat exchangers for the cooling and heat pipes, and the material cost is high. Therefore, how to save materials and at the same time achieve the purpose of using outdoor low-temperature air to provide cooling capacity for the indoor side to improve the annual energy efficiency of the air conditioner is a technical problem that needs to be solved by those skilled in the art.

SUMMARY OF THE INVENTION

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 cold source while saving materials, reduce energy consumption, and save energy.

In order to solve the problems existing in the prior art, the present invention provides a refrigeration/heat pipe composite cabinet air conditioning system and a control method thereof, including a cabinet shell, and a condenser, an external circulation fan, a compressor, an evaporator, a condenser, an external circulation fan, a compressor, an evaporator, The internal circulation fan and the variable throttle mechanism include 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, and one outlet of the three-way valve is controlled by an electronic The expansion valve is connected in series to the inlet of the evaporator, and the other outlet of the three-way valve is directly bypassed to the inlet of the evaporator through the pipeline.

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 four-way valve through the four-way valve. The suction port of the compressor.

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

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.

Preferably, the four-way valve and the suction port of the compressor are connected through a gas-liquid separator pipeline.

Preferably, the throttling variable mechanism can also be a two-stage electronic expansion valve, a precision electric ball valve with adjustable opening and other special valve parts, or other system parts such as an electric ball valve and an electronic expansion valve according to the equivalent form connection.

Preferably, the evaporator is arranged at the innermost end of the cabinet shell, and its position height is lower than the position height of the condenser and the variable throttle mechanism.

Preferably, the specific control method is as follows:

After receiving the startup command, the composite cabinet air-conditioning unit completes the self-test, detects the temperature inside the cabinet Tin and the ambient temperature Tout outside the cabinet, and the controller calculates the ambient temperature difference between the inside and outside of the cabinet ΔTa=Tin-Tout.

When the cabinet temperature Tin ≤ cabinet set temperature (target temperature) Ts (such as 35 ℃), the unit is on standby.

When the temperature inside the cabinet Tin > the set temperature Ts in the cabinet, select the operation mode according to the ambient temperature difference ΔTa inside and outside the cabinet:

If the ambient temperature difference between the inside and outside of the cabinet is large, ΔTa > ΔTmin (for example, 20°C), the unit will run in the heat pipe cooling mode taking into account the requirements of energy saving and cooling of the cabinet. When the temperature difference between the inside and outside of the cabinet changes to a small value, ΔTa≤ΔTmin, the heat pipe cooling mode cannot meet the requirements. The cooling of the cabinet is required. At this time, the unit switches to the air-conditioning refrigeration mode, the compressor is put into operation, and the throttling mechanism throttles and reduces the pressure, which quickly reduces the air temperature in the cabinet, so that the heating load in the cabinet can work reliably.

After the unit operates in the air-conditioning cooling mode, until the ambient temperature difference between the inside and outside of the cabinet changes enough, ΔTa > ΔTmax (such as 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 cooling requirements of the cabinet.

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

(1) When the unit operates in the air-conditioning refrigeration mode, the position of the spool ball of the four-way valve changes to the following state under the action of the coil excitation: the two passages of the spool ball pass through the oil separator and connect to the compressor exhaust port and the condenser inlet. , the other way through the gas-liquid separator is connected to the outlet of the evaporator and the suction port of the compressor, the three-way valve closes the bypass branch, and connects to the branch where the electronic expansion valve is located, and the electronic expansion valve opens the throttling effect according to the superheat degree. . When the compressor is running, the low-pressure vapor of the refrigerant is inhaled by the compressor and compressed into high-pressure vapor before being discharged to the condenser. At the same time, the air sucked by the external circulation fan flows through the condenser to take away the heat released by the refrigerant and condense the high-pressure refrigerant vapor. It is a high-pressure liquid. The high-pressure liquid is throttled and depressurized by an electronic expansion valve and then sprayed into the evaporator, and evaporates at a corresponding low pressure. It absorbs the surrounding heat and heats up and is sucked again by the compressor. At the same time, the internal circulation fan makes the air continuously pass through the evaporator. The fins are used for heat exchange, and the air cooled after heat exchange is sent to the cabinet;

(2) When the unit operates in the heat pipe cooling mode, the position of the spool ball of the four-way valve is reset to the following state under the action of the coil excitation: the two passages of the spool ball pass through the oil separator and the gas-liquid separator and are respectively connected to the compressor. The exhaust port and the suction port are short-circuited, and the other is connected to the inlet of the condenser and the outlet of the evaporator, so that the condenser and the evaporator form an independent heat pipe natural circulation system, the compressor is stopped, and the three-way valve is closed where the electronic expansion valve is located. Branch, open the bypass branch so that the whole throttling variable mechanism has no throttling and depressurization effect, and the local resistance is small, which meets the requirements of the heat pipe natural circulation principle with small resistance along the refrigerant path. At this time, the refrigerant in the evaporator will continue to flow. Endothermic evaporation, the gaseous refrigerant rises to the condenser, condenses and releases heat to become condensate, and returns to the evaporator through the fully open throttling variable mechanism without throttling under the action of gravity, completing a natural circulation of the heat pipe, while the internal The circulating fan makes the air in the cabinet continuously exchange heat through the fins of the evaporator, and sends the cooled air after the heat exchange to the cabinet; the external circulation fan makes the air outside the cabinet continuously absorb heat through the fins of the condenser, and The heated air after heat exchange is exhausted to the outside of the cabinet, and in this way, the unit is in an effective heat pipe cooling state, and the heat in the cabinet is transferred to the outside environment through the natural circulation of the heat pipe.

Compared with the prior art, the beneficial effects of the present invention are:

The refrigeration/heat pipe composite type cabinet air conditioning system and its control method are provided with a four-way valve, a condenser, an external circulation fan, a variable throttle 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 through the automatic control system according to different working conditions, so that the system can always run in its energy-saving mode under different working conditions, and ensure that the temperature in the cabinet is within a reasonable range. At the same time, the operating cost of the system is reduced, the energy consumption is reduced, and the comprehensive energy efficiency ratio is improved throughout the year. In addition, the composite cabinet air conditioner has a reasonable structure design, simple pipelines, saving material costs; intelligent automatic control operation, convenient operation and maintenance.

Description of drawings

Fig. 1 is the principle diagram of air-conditioning refrigeration mode of the present invention;

FIG. 2 is a schematic diagram of a heat pipe heat dissipation mode of the present invention;

3 is a schematic diagram of a first alternative form of the preferred throttle mechanism of the present invention;

4 is a schematic diagram of a second alternative form of the preferred throttle mechanism of the present invention;

FIG. 5 is a schematic flowchart of the control method of the present invention.

In the figure: 1. Four-way valve; 2. Condenser; 3. External circulation fan; 4. Throttle variable 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 arrow in the figure represents the refrigerant flow direction)

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

Example 1

As shown in Figure 1-5, in the figure, it is assembled by the following components:

Assembly instructions: Install the condenser 2, the external circulation fan 3, the throttle variable mechanism 4, the three-way valve 5, the electronic expansion valve 6, the compressor 7, the evaporator 8 and the inner circulation fan 9 inside the cabinet shell, and then Install the refrigeration system connecting pipeline, the controller and the four-way valve 1 inside the cabinet shell, and connect the refrigeration system connecting pipeline to the exhaust port of the compressor 7, the inlet of the condenser 2, and the evaporator 8 through the four-way valve 1 respectively. The outlet of the three-way valve 5 and the suction port of the compressor 7 are connected to the outlet of the condenser 2 through the pipeline, and 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. The other outlet of the through valve 5 is bypassed directly to the inlet of the evaporator 8 through a pipeline.

Embodiment 2

As shown in Figure 1-5, in the figure, it is assembled by the following components:

Assembly instructions: Install the condenser 2, the external circulation fan 3, the throttling variable mechanism 4, the compressor 7, the evaporator 8, the internal circulation fan 9, the oil separator 10 and the 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, and connect the refrigeration system connecting pipeline through the four-way valve 1 to the air outlet of the oil separator 10, the inlet of the condenser 2, and the evaporator 8 respectively. The outlet of the oil separator 10 and the inlet of the gas-liquid separator 12, the air outlet of the oil separator 10 and the exhaust port of the compressor 7 are connected by pipelines, the oil return port of the oil separator 10 and the compressor 7 are connected by the oil return capillary 11, and the gas The outlet of the liquid separator 12 and the suction 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 a pipeline of the throttling variable mechanism 4 .

When the unit is switched from the air conditioning refrigeration mode to the heat pipe cooling mode, the action sequence of each component is: the throttling mechanism 4 is fully closed, the refrigerant of the unit is recovered into the condenser 2 under the drive of the compressor 7, and after a period of time t, the four-way valve 1 The position of the spool ball is switched from the air conditioning refrigeration state to the heat pipe cooling state, the compressor 7 is stopped, the throttle variable mechanism 4 is fully opened, and the inner circulation fan 9 and the outer circulation fan 3 automatically adjust the speed according to the heat pipe cooling load program. The above-mentioned time t for recovering the refrigerant is intelligently controlled by the control module according to the amount of refrigerant required by the heat load of the heat pipe heat dissipation mode.

When the unit is switched from the heat pipe cooling mode to the air conditioning cooling mode, the action sequence of each component is as follows: the position of the spool ball of the four-way valve 1 is switched from the heat pipe cooling state to the air conditioning cooling state, and the throttle variable mechanism 4 is reset according to the air conditioning and cooling logic. When the initial opening degree is reached, the inner circulation fan 9 and the outer circulation fan 3 automatically adjust the speed according to the heat load by the program, the compressor 7 starts, and then the components of the unit operate according to the air conditioning and refrigeration logic.

Figure 3 is a two-stage electronic expansion valve. In the air-conditioning refrigeration mode, the valve is adjusted at a small opening, which plays the role of throttling and reducing the pressure of the refrigerant; in the heat pipe cooling mode, the valve is fully open, and the The diameter is reasonable and the local resistance is extremely small, which meets the requirements of the small resistance of the refrigerant along the path of the natural circulation principle of the heat pipe.

Figure 4 is a precision electric ball valve with adjustable opening. In the air conditioning refrigeration mode, the valve can precisely adjust the refrigerant flow through the groove on the structure at a small opening; in the heat pipe cooling mode, the valve Fully open to meet the requirement of small resistance along the way of the refrigerant in the principle of natural circulation of the heat pipe.

The foregoing has shown and described 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-mentioned embodiments, and the above-mentioned 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. Under the premise, the present invention will also have various changes and improvements, and these changes and improvements all fall within the scope of the claimed invention. The claimed scope of the present invention is defined by the appended claims and their equivalents.

Claims (7)

1. A refrigeration/heat pipe composite type cabinet air-conditioning system and a control method thereof, comprising a cabinet shell, characterized in that: the inside of the cabinet shell is provided with a condenser (2), an external circulation fan (3), a compressor (7), an internal A circulating fan (9) and a variable throttle mechanism (4), the variable throttle mechanism (4) includes a three-way valve (5) and an electronic expansion valve (6), the inlet of the three-way valve (5) The outlet of the condenser (2) is connected through a 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 connected by a pipeline The road is directly bypassed to the inlet of the evaporator (8), the evaporator (8) is arranged at the bottom end of the cabinet shell, and its position is lower than the condenser (2) and the throttling variable mechanism (4) position height. 2. A refrigeration/heat pipe composite type cabinet air-conditioning system and control method thereof according to claim 1, characterized in that: 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 suction port of the compressor (7) through the four-way valve (1). 3. A refrigeration/heat pipe composite type cabinet air-conditioning system and control method thereof according to claim 1, wherein the outlet of the condenser (2) and the inlet of the evaporator (8) are variable by throttling Mechanism (4) pipeline connection. 4. A refrigeration/heat pipe composite type cabinet air conditioning system and control method thereof according to claim 1, 2, characterized in that: oil separation can be increased between the four-way valve (1) and the compressor (7) (10), the four-way valve (1) and the exhaust port of the compressor (7) are connected through the oil separator (10) pipeline, and the oil return port of the oil separator (10) is connected to the compressor (7) Connect through the oil return capillary (11). 5. A refrigeration/heat pipe composite cabinet air conditioning system and control method thereof according to claim 1, 2, characterized in that: a gas-liquid can be added between the four-way valve (1) and the compressor (7) The separator (12), the four-way valve (1) and the suction port of the compressor (7) are connected by pipelines of the gas-liquid separator (12). 6. A refrigeration/heat pipe composite type cabinet air-conditioning system and control method thereof according to claim 1, characterized in that: the variable throttle mechanism (4) can also be a two-stage electronic expansion valve (6), a Special valve parts such as precision electric ball valve with adjustable opening, and other system parts such as electric ball valve and electronic expansion valve (6) can also be connected in an equivalent form. 7. A refrigeration/heat pipe composite type cabinet air-conditioning system and control method thereof according to any one of claims 1-6, wherein the specific control method is as follows: After receiving the startup command, the composite cabinet air-conditioning unit completes the self-test, detects the temperature inside the cabinet Tin and the ambient temperature Tout outside the cabinet, and the controller calculates the ambient temperature difference between the inside and outside of the cabinet ΔTa=Tin-Tout. When the cabinet temperature Tin ≤ cabinet set temperature (target temperature) Ts (such as 35 ℃), the unit is on standby. When the temperature inside the cabinet Tin > the set temperature Ts in the cabinet, select the operation mode according to the ambient temperature difference ΔTa inside and outside the cabinet: If the temperature difference ΔTa between the inside and outside of the cabinet is relatively large, ΔTa > ΔTmin (such as 20°C), the unit will run in the heat pipe heat dissipation mode taking into account the requirements of energy saving and cooling of the cabinet. When the temperature difference between the inside and outside of the cabinet changes to a small value, ΔTa ≤ ΔTmin, the heat pipe heat dissipation mode cannot meet the requirements. The cooling of the cabinet is required. At this time, the unit switches to the air-conditioning cooling mode, the compressor (7) is put into operation, and the throttling mechanism throttles and reduces the pressure to rapidly reduce the air temperature in the cabinet, so that the heating load in the cabinet can work reliably. After the unit operates in the air-conditioning cooling mode, until the ambient temperature difference between the inside and outside of the cabinet changes enough, ΔTa > ΔTmax (such as 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 cooling requirements of the cabinet. In this way, the unit control module intelligently selects the operation mode according to the ambient temperature difference ΔTa inside and outside the cabinet, taking into account the energy saving and the temperature requirements of the heating load in the cabinet, until the cabinet temperature Tin ≤ the set temperature Ts in the cabinet, the unit is on standby. (1) When the unit operates in the air-conditioning refrigeration mode, the position of the spool ball of the four-way valve 1 is transferred to the following state under the action of the coil excitation: the two passages of the spool ball pass through the oil separator (10) all the way to the compressor (7) The exhaust port and the inlet of the condenser (2), the other way is connected to the outlet of the evaporator 8 and the suction port of the compressor (7) through the gas-liquid separator (12), and the three-way valve (5) closes the bypass branch and connects the electronic In the branch where the expansion valve (6) is located, the electronic expansion valve (6) opens the throttling effect to an appropriate opening degree according to the degree of superheat. The compressor (7) operates, and the low-pressure vapor of the refrigerant is sucked in by the compressor (7) and compressed into high-pressure vapor before being discharged to the condenser (2), while the air sucked by the external circulation fan (3) flows through the condenser (2) , take away the heat released by the refrigerant, so that the high-pressure refrigerant vapor condenses into a high-pressure liquid, and the high-pressure liquid is throttled and depressurized by the electronic expansion valve (6) and then sprayed into the evaporator (8), and evaporated at the corresponding low pressure. The surrounding heat is inhaled again by the compressor (7) after heating up, and at the same time, the internal circulation fan (9) makes the air continuously pass through the fins of the evaporator (8) for heat exchange, and sends the cooled air after the heat exchange to the cabinet. ; (2) When the unit operates in the heat pipe cooling mode, the position of the spool ball of the four-way valve (1) is reset to the following state under the action of the coil excitation: the two passages of the spool ball pass through the oil separator (10) all the way, and the gas-liquid separation The compressor (12) is connected to the exhaust port and the suction port of the compressor (7) respectively, so that they are short-circuited, and the other way is connected to the inlet of the condenser (2) and the outlet of the evaporator (8), so that the condenser (2) and the evaporator (8) are connected. (8) An independent heat pipe natural circulation system is formed, the compressor (7) is stopped, the three-way valve (5) closes the branch where the electronic expansion valve (6) is located, and the bypass branch is opened to make the entire throttle variable mechanism (4) There is no throttling and depressurization effect, and the local resistance is small, which meets the requirement of small resistance of the refrigerant along the path of the natural circulation principle of the heat pipe. At this time, the refrigerant in the evaporator (8) will continue to absorb heat and evaporate, and the gaseous refrigerant will rise to the condenser ( 2) The condensed and released heat becomes condensed liquid, and under the action of gravity, it is returned to the evaporator (8) through the fully open throttling variable mechanism (4) without throttling to complete a natural circulation of the heat pipe, while the internal circulation fan ( 9) Make the air in the cabinet continuously exchange heat through the fins of the evaporator (8), and send the cooled air after the heat exchange to the cabinet; the external circulation fan (3) makes the air outside the cabinet continuously pass through the condenser (2). ) fins absorb heat and discharge the heated air after heat exchange to the outside of the cabinet. In this way, the unit is in an effective heat pipe cooling state, and the heat inside the cabinet is transferred to the outside environment through the natural circulation of the heat pipe.

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