CN106679210A - Novel variable-pressure-ratio vapor compression/heat pipe integrated machine room air conditioning system and control method thereof - Google Patents

Abstract

The invention discloses a novel variable pressure ratio vapor compression/heat pipe integrated computer room air conditioning system, comprising a compressor, a condenser, a throttling device, an evaporator, an outdoor fan, an indoor fan and a controller; the compressor, the condenser , throttling device, and evaporator are connected in series through pipelines in sequence; the outdoor fan is arranged on one side of the condenser; the indoor fan is arranged on one side of the evaporator; the controller is respectively connected to the compressor and the condenser through a data transmission line , throttling device, outdoor fan, indoor fan, evaporator and controller are connected. The invention also discloses a control method of a novel variable pressure ratio vapor compression/heat pipe integrated machine room air conditioning system. The system of the present invention is a new variable pressure ratio integrated energy-saving system with vapor compression refrigeration function and heat pipe cooling function, which can provide suitable cooling temperature and cooling capacity, and realize the integrated computer room air conditioning system under the condition that the outdoor temperature changes greatly throughout the year efficient and stable operation.

Description

A new variable pressure ratio vapor compression/heat pipe integrated computer room air conditioning system and its Control Method

technical field

The invention relates to the technical field of refrigeration and air conditioning. More specifically, it relates to a novel variable pressure ratio vapor compression/heat pipe integrated computer room air conditioning system and a control method thereof.

Background technique

With the development and application of information technology, the number of data centers has increased rapidly. Globally, data centers have become a major energy consumer, and the total energy consumption of data centers has accounted for 1.3% of the world's total electricity consumption. The heat pipe air-conditioning system has attracted attention because it can utilize the outdoor natural cold source without introducing outdoor pollutants. However, since the heat pipe natural cooling cannot operate in the season when the outdoor temperature is high, research and development have both vapor compression refrigeration and heat pipe cooling functions. Integrated computer room air conditioning system has become an inevitable trend. The existing vapor compression/heat pipe integrated air conditioning system can be divided into vapor compression/heat pipe shared type, active cooling source/natural cooling source parallel type, active cooling source/natural cooling source series type and three-medium heat exchange based on the basic principle. Vapor compression/loop heat pipe integrated air conditioning system.

Vapor compression/heat pipe shared air-conditioning system On the one hand, due to the difference in the flow and heat exchange mechanism of refrigerant in the evaporator and condenser, and the distribution of refrigerant in the heat pipe mode and vapor compression refrigeration mode, the optimization of heat exchanger and refrigeration The filling amount of the agent can only be designed based on one mode, which reduces the performance in the other mode; The large hidden danger of reliability seriously restricts the practical application of the system.

Active cooling source/natural cooling source parallel and series air conditioning systems have different refrigerant distributions in the two series or parallel condensers under different operating conditions, and the solenoid valve switches in the parallel system There are also reliability concerns.

Therefore, it is necessary to provide a variable pressure ratio vapor compression/heat pipe integrated computer room air conditioning system based on a free piston compressor to solve the above hidden dangers.

Contents of the invention

An object of the present invention is to provide a novel variable pressure ratio vapor compression/heat pipe integrated computer room air conditioning system.

Another object of the present invention is to provide a control method of a novel variable pressure ratio vapor compression/heat pipe integrated computer room air conditioning system.

To achieve the above object, the present invention adopts the following technical solutions:

A new variable pressure ratio vapor compression/heat pipe integrated computer room air conditioning system, including a compressor, a condenser, a throttling device, an evaporator, an outdoor fan, an indoor fan and a controller;

Compressor: According to the condensing temperature signal received by the controller, the compressor stroke (the distance from the top dead center to the bottom dead center) can be changed to adjust the compression ratio to adapt to the condensing temperature and avoid over-compression, so that the condensing pressure can follow the outdoor The temperature drops gradually; the operating frequency of the compressor can also be changed according to the evaporation temperature signal received by the controller, and the evaporation temperature and refrigerant flow rate can be controlled so that it can provide suitable cooling temperature and cooling capacity, especially when the outdoor temperature is low After a certain value in the room, the compressor can operate with a very small compression ratio (similar to the operation of the air pump mode) and only provide the resistance that the refrigerant circulation needs to overcome (especially the gravity provided by the refrigerant gas-liquid height difference can be used as When the refrigerant flows, the compressor can stop running), the system operates in the loop heat pipe mode, efficiently utilizes the outdoor natural cold source, and realizes the efficient and stable operation of the integrated computer room air conditioning system under the condition of large changes in outdoor temperature throughout the year;

The condenser and the evaporator are shared by the vapor compression system and the heat pipe cooling system; when the vapor compression refrigeration system is running, the condenser and the evaporator are the condenser and the evaporator of the vapor compression refrigeration system, and when the heat pipe cooling system is running, the condenser and the evaporator are The evaporator is the evaporation end and the condensation end of the heat pipe cooling system;

The throttling device is a throttling device with a variable throttling area. By changing the throttling area of the throttling device, it can be adjusted to control the suction superheat of the compressor, maintain the stability of the compressor, and meet the needs of vapor compression mode and heat pipe mode conversion. ;

Outdoor fan: the air volume of the air-cooled heat exchanger can be adjusted, and then the cooling capacity of the unit can be adjusted to accurately control the indoor temperature;

Indoor fan: enhance heat transfer with evaporator;

The controller can receive temperature signal feedback from the evaporator and condenser, and control the compression ratio and operating speed of the compressor, the speed or number of fans (the speed of the water pump), and the opening of the throttling device through the control branch.

The compressor, condenser, throttling device, and evaporator are connected in series through pipelines in sequence; the outdoor fan is set on the side of the condenser; the indoor fan is set on the side of the evaporator; the controller is connected through a data transmission line Connect with compressor, condenser, throttling device, evaporator, outdoor fan and indoor fan respectively.

The above system is an air-cooled variable pressure ratio vapor compression/heat pipe integrated computer room air conditioning system, and the system can also be a water-cooled variable pressure ratio vapor compression/heat pipe integrated computer room air conditioning system, that is, the outdoor fan is replaced by a cooling water circuit pump, The water volume of the water-cooled heat exchanger is adjusted by the speed of the water pump in the cooling water circuit, and then the cooling capacity of the unit is adjusted to control the indoor temperature more accurately.

Further, the compressor is a free piston compressor;

Further, the throttling device is a throttling device with a variable throttling area, preferably a thermal expansion valve or an electronic expansion valve;

Further, the condenser and the evaporator are microchannel heat exchangers, finned tube heat exchangers, casing heat exchangers or plate heat exchangers.

Further, the outdoor fan is a variable-speed fan or several fans, and the air volume of the air-cooled heat exchanger is adjusted by adjusting the fan speed or the number of fans turned on.

A control method of a novel variable pressure ratio vapor compression/heat pipe integrated computer room air conditioning system, including the following three modes:

1) Vapor compression refrigeration mode: When the outdoor temperature is high, that is, when the outdoor temperature is higher than the condensation temperature of the heat pipe circuit, the compressor is first started, and the refrigerant in the vapor compression refrigeration circuit is compressed by the compressor and condensed in the condenser. After releasing heat, it enters the throttling device, and then enters the evaporator after throttling and reducing pressure, and returns to the compressor after evaporating and absorbing heat;

Among them, the controller can process the condensing temperature feedback signal fed back by the condenser, and then change the compressor stroke to adjust the compression ratio, and then adjust the condensing temperature to avoid over-compression, so that the condensing temperature can gradually decrease as the outdoor temperature drops; It can process the evaporating temperature feedback signal fed back by the evaporator, and then change the operating frequency of the compressor to adapt to the evaporating temperature and adjust the refrigerant flow rate, so that it can provide appropriate cooling temperature and cooling capacity;

2) Combined cooling mode: when the outdoor temperature is low, that is, the outdoor temperature is lower than the condensation temperature of the heat pipe circuit, but the difference between the outdoor temperature and the condensation temperature of the heat pipe is not enough to maintain the predetermined temperature of the entire data center, the controller sends a signal in due course. Automatically turn on the compressor to provide a certain amount of power for the heat pipe cooling system, and open the throttling device to the maximum; at this time, the refrigerant enters the condenser under the power provided by the compressor, and flows through the state of minimum resistance after condensing and releasing heat The lower throttling device directly goes to the evaporator to evaporate and absorb heat, and finally returns to the compressor;

Among them, the controller processes the evaporating temperature feedback signal from the evaporator, and then changes the operating frequency of the compressor to adapt to the evaporating temperature and adjust the refrigerant flow rate, so that it can provide suitable cooling temperature and cooling capacity;

3) Heat pipe mode: When the outdoor temperature is low enough, that is, the outdoor temperature is lower than the condensation temperature of the heat pipe, and the cooling effect achieved by the difference between the outdoor temperature and the condensation temperature of the heat pipe circuit can meet the predetermined temperature maintenance of the entire computer room, the controller Send a signal at the right time to turn off the compressor, but at the same time open the air inlet and outlet of the compressor, and open the opening of the throttling device to the maximum; at this time, the refrigerant condenses in the condenser, and after condensing and releasing heat, under the action of gravity Enter the evaporator, evaporate and absorb heat, and then return to the condenser;

The entire system operates under the action of the gravity of the refrigerant in the pipeline circuit and the power provided by the compressor.

Further, the system can be an air-cooled variable pressure ratio vapor compression/heat pipe integrated computer room air-conditioning system. In three modes, the outdoor fan is adjusted to adjust the wind chime of the condenser to adjust the cooling capacity of the unit. Control the temperature in the room.

Further, the system can be a water-cooled variable pressure ratio vapor compression/heat pipe integrated computer room air-conditioning system. In three modes, the water volume of the condenser is adjusted by the speed of the water pump in the cooling water circuit to adjust the cooling capacity of the unit. Precisely control the temperature in the room.

The beneficial effects of the present invention are as follows:

The present invention is a new variable pressure ratio vapor compression/heat pipe integrated data center air conditioning system, which is a new variable pressure ratio integrated energy-saving system with vapor compression refrigeration function and heat pipe cooling function, and can provide suitable cooling temperature and refrigeration To achieve efficient and stable operation of the all-in-one computer room air conditioning system in the case of large changes in outdoor temperature throughout the year. Compared with the traditional vapor compression/heat pipe integrated air conditioner, it can not only realize that it does not need frequent opening of the solenoid valve to switch modes, but also reduce the harm of heat exchanger performance degradation caused by changes in refrigerant distribution.

Description of drawings

The specific implementation manners of the present invention will be further described in detail below in conjunction with the accompanying drawings.

Figure 1 shows an air-cooled variable pressure ratio vapor compression/heat pipe integrated computer room air conditioning system;

Among them, 1. Compressor; 2. Condenser; 3. Throttling device; 4. Evaporator; 5. Outdoor fan; 6. Indoor fan; 7. Controller; 8. Condenser temperature measurement feedback branch; 9. Evaporator temperature measurement feedback branch; 10. Outdoor fan control branch; 11. Throttle device control branch; 12. Compressor control branch; 13. Indoor fan control branch.

Figure 2 shows a water-cooled variable pressure ratio vapor compression/heat pipe integrated computer room air conditioning system;

Among them, 1. Compressor; 2. Condenser; 3. Throttling device; 4. Evaporator; 5'. Cooling water circuit pump; 6. Indoor fan; 7. Controller; 8. Condenser temperature measurement feedback branch ;9, evaporator temperature measurement feedback branch; 10, outdoor fan control branch; 11, throttling device control road; 12, compressor control branch; 13, indoor fan control branch.

Fig. 3 shows the schematic diagram of the variable pressure ratio of the free piston compressor;

Among them, 3-1, top dead center of free piston stroke; 3-2, bottom dead center of free piston large stroke; 3-3, bottom dead center of free piston small stroke;

Fig. 4 shows free-piston compressor to avoid or reduce overcompression pressure-enthalpy diagram;

Among them, A, general compressor overcompression pressure enthalpy diagram; B, variable pressure ratio free piston compressor ideal pressure enthalpy diagram.

detailed description

In order to illustrate the present invention more clearly, the present invention will be further described below in conjunction with preferred embodiments and accompanying drawings. Similar parts in the figures are denoted by the same reference numerals. Those skilled in the art should understand that the content specifically described below is illustrative rather than restrictive, and should not limit the protection scope of the present invention.

Example 1: Air-cooled variable pressure ratio vapor compression/heat pipe integrated computer room air conditioning system

As shown in Figure 1, the air-cooled variable pressure ratio vapor compression/heat pipe integrated computer room air conditioning system includes a compressor 1, a condenser 2, a throttling device 3, an evaporator 4, an outdoor fan 5, an indoor fan 6, and a controller 7 . The outlet of the evaporator 4 is connected to the inlet a of the compressor 1 through a pipeline; the gas outlet b of the compressor 1 is connected to the inlet of the condenser 2 through a pipeline; the outlet of the condenser 2 is connected to the inlet of the throttle device 3 Through the pipeline inlet, the outlet of the throttling device 3 is connected to the inlet of the evaporator 4 through a pipeline; the compressor 1 and the throttling device 4 are also controlled by the compressor control branch 12 and the throttling device control branch respectively 11 is connected to the controller 7, and the condenser 2 and the evaporator 4 are also connected to the controller 7 through the condenser temperature measurement feedback branch 8 and the evaporator temperature measurement feedback branch 9 respectively; the outdoor fan 5 is set One side of the condenser 2 is connected to the controller 7 through the outdoor fan control branch 10; the indoor fan 6 is provided on the side of the evaporator 4 and connected to the controller 7 through the indoor fan control branch 13;

Wherein, the condenser 2 is an air-cooled heat exchanger, and the outdoor fan 5 can be a variable-speed fan or several fans, and the air volume of the air-cooled heat exchanger can be adjusted by adjusting the fan speed or the number of fans turned on.

Example 2: Water-cooled variable pressure ratio vapor compression/heat pipe integrated computer room air conditioning system

As shown in Figure 2, the component composition and connection relationship of the water-cooled variable pressure ratio vapor compression/heat pipe integrated computer room air conditioning system are the same as those of the air-cooled variable pressure ratio vapor compression/heat pipe integrated computer room air conditioner system, except that the condenser 2 is water-cooled For the heat exchanger, the outdoor fan 5 in FIG. 1 is replaced by the cooling water circuit pump 5' in FIG. 2, and the water volume of the water-cooled heat exchanger is adjusted by the speed of the cooling water circuit pump 5'.

Embodiment 3 A control method of a novel variable pressure ratio vapor compression/heat pipe integrated computer room air conditioning system

The control method of the new variable pressure ratio vapor compression/heat pipe integrated computer room air conditioning system includes three modes:

1) Vapor compression refrigeration mode

When the outdoor temperature is high, that is, when the outdoor temperature is higher than the condensation temperature of the heat pipe circuit, as shown in Figure 1 or 2, the free piston compressor 1 is first started, and the refrigerant in the vapor compression refrigeration circuit is compressed by the free piston compressor 1 Finally, it condenses in the condenser 2, and enters the variable throttle area throttling device 3 after condensing and releasing heat, and then enters the evaporator 4 after throttling and reducing pressure, and returns to the free piston compressor 1 after evaporating and absorbing heat;

Among them, the controller 7 can process the condensing temperature feedback signal transmitted through the condenser temperature measurement feedback branch 8, and then change the compressor stroke (top dead center 3-1 to bottom dead center) through the 12 compressor control branch point 3-2, 3-3) to adjust the compression ratio (as shown in Figure 3), and then adjust the condensing pressure (temperature) to avoid overcompression, so that the condensing pressure can gradually decrease as the outdoor temperature drops (as shown in Figure 4 shown); the evaporation temperature feedback signal transmitted through the evaporator temperature measurement feedback branch 9 can also be processed, and then the operating frequency of the compressor 1 can be changed through the compressor control branch 12 to adapt to the evaporation pressure (temperature) and Adjust the flow rate of the refrigerant so that the appropriate cooling temperature and cooling capacity can be provided;

2) Combined cooling mode

When the outdoor temperature is low, that is, the outdoor temperature is lower than the condensation temperature of the heat pipe circuit, but the difference between the outdoor temperature and the condensation temperature of the heat pipe is not enough to maintain the predetermined temperature of the entire data center, the controller 7 sends a signal in due course according to the working condition, and passes The compressor control branch 12 automatically turns on the free piston compressor 1 to provide certain power for the heat pipe cooling system, and the throttling device 3 opens to the maximum through the throttling device control branch 11 . At this time, the refrigerant enters the condenser 2 under the power provided by the free piston compressor 1, and after condensing and releasing heat, it flows through the throttling device 3 in the state of minimum resistance, directly to the evaporator 4 to evaporate and absorb heat, and finally returns to the free Piston compressor 1. Among them, the controller 7 processes the evaporating temperature feedback signal transmitted through the evaporator temperature measurement feedback branch 9, and then changes the operating frequency of the compressor through the compressor control branch 12 to adapt to the evaporating pressure (temperature) and adjust the refrigerant Flow rate, so that it can provide suitable cooling temperature and cooling capacity;

3) Heat pipe mode

When the outdoor temperature is low enough, that is, the outdoor temperature is lower than the condensation temperature of the heat pipe, and the cooling effect achieved by the difference between the outdoor temperature and the condensation temperature of the heat pipe circuit can meet the predetermined temperature maintenance of the entire computer room, as shown in Figure 1 or 2 , the controller 7 sends a signal in due course according to this working condition, and closes the free piston compressor 1 through the compressor control branch 12, but simultaneously opens the air inlet a and the air outlet b of the compressor, and the throttling device control branch 11 will The opening degree of throttling device 3 is opened to the maximum. At this time, the refrigerant condenses in the condenser 2, and enters the evaporator 4 under the action of gravity after condensing and releasing heat, and returns to the condenser 2 after evaporating and absorbing heat;

The entire system operates under the action of the gravity of the refrigerant in the pipeline circuit and the power provided by the compressor.

Wherein, when the system is an air-cooled variable pressure ratio vapor compression/heat pipe integrated computer room air-conditioning system, in various operating modes, the air volume of the condenser 2 is adjusted by adjusting the speed of the outdoor fan 5 or the number of units turned on, and then the air volume of the condenser 2 is adjusted. The cooling capacity of the unit is adjusted to control the indoor temperature more accurately.

When the system is a water-cooled variable pressure ratio vapor compression/heat pipe integrated computer room air-conditioning system, in various operating modes, the water volume of the condenser 2 is adjusted by the rotation speed of the cooling water circuit water pump 5', and then the cooling capacity of the unit is adjusted. Adjust to more precisely control the temperature in the room.

Obviously, the above-mentioned embodiments of the present invention are only examples for clearly illustrating the present invention, rather than limiting the implementation of the present invention. For those of ordinary skill in the art, on the basis of the above description, they can also make It is not possible to exhaustively list all the implementation methods here, and all obvious changes or changes derived from the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims (9)

1. a kind of novel changable pressure ratio it is steam compressed/heat pipe Integral computer-room air-conditioning system, it is characterised in that include：Compressor （1）, condenser（2）, throttling arrangement（3）, evaporimeter（4）, outdoor fan（5）, indoor fan（6）And controller（7）；The pressure Contracting machine（1）, condenser（2）, throttling arrangement（3）, evaporimeter（4）Pass sequentially through placed in series together；The outdoor fan sets Put in condenser（2）Side；The indoor fan is arranged on evaporimeter（4）Side；The controller（7）By data line Respectively with compressor（1）, condenser（2）, throttling arrangement（3）, evaporimeter（4）, outdoor fan（5）, indoor fan（6）It is connected Connect.

2. system according to claim 1, it is characterised in that：The outdoor fan（5）Could alternatively be chilled(cooling) water return (CWR) Water pump（5’）.

3. system according to claim 1 and 2, it is characterised in that：The compressor（1）For free piston compressor.

4. system according to claim 1 and 2, it is characterised in that：The throttling arrangement（3）For the section of variable restrictor area Stream device, preferably heating power expansion valve or electric expansion valve.

5. system according to claim 1 and 2, it is characterised in that：The condenser（2）And evaporimeter（4）For microchannel Heat exchanger, fin-tube heat exchanger, double pipe heat exchanger or plate type heat exchanger.

6. system according to claim 1, it is characterised in that：The outdoor fan（5）For speed-changing draught fan or several Fans Combine.

7. a kind of control method of the system as described in claim 1-6 is arbitrary, it is characterised in that including following Three models：

1）Vapor compression refrigeration pattern：When outdoor temperature is higher, i.e., when outdoor temperature is higher than heat pipe circuit condensation temperature, open first Dynamic compressor（1）, the cold-producing medium Jing compressors in vapor compression refrigeration loop（1）After compression, in condenser（2）Middle condensation, it is cold Throttling arrangement is entered after solidifying heat release（3）, evaporimeter is entered back into after reducing pressure by regulating flow（4）, compressor is returned to after evaporation endothermic （1）；

Wherein, controller（7）Both can be to condenser（2）The condensation temperature feedback signal of feedback is processed, and then changes pressure Contracting machine（1）Stroke adjusts condensation temperature adjusting compression ratio, it is to avoid overcompression so that condensation temperature can be with outdoor temp Degree decline is gradually reduced；Also can be to evaporimeter（4）The evaporating temperature feedback signal of feedback is processed, and then changes compressor （1）Operating frequency, adapt to evaporating temperature and adjusting refrigerant flow rate, enabling provide suitable cryogenic temperature and refrigeration Amount；

2）Joint refrigeration pattern：When outdoor temperature is relatively low, i.e., outdoor temperature is less than heat pipe circuit condensation temperature, but outdoor temperature When being not enough to keep the predetermined temperature of whole data center with the difference of heat pipe condensation temperature, controller（7）Signal is sent in good time, Automatically turn on compressor（1）, provide certain power to heat pipe cooling system, and by throttling arrangement（3）Aperture reach maximum； Now cold-producing medium is in compressor（1）There is provided and enter under power condenser（2）, flow through in the state of minimum drag after condensation heat release Throttling arrangement（3）, directly to evaporimeter（4）Evaporation endothermic, finally returns compressor（1）；

Wherein, controller（7）To evaporimeter（4）The evaporating temperature feedback signal for transmitting is processed, and compressor is then changed again （1）Operating frequency, adapt to evaporating temperature and adjusting refrigerant flow rate so that it can provide suitable chilling temperature and refrigeration Amount；

3）Heat pipe pattern：When outdoor temperature is sufficiently low, i.e., outdoor temperature is less than heat pipe condensation temperature, and outdoor temperature and heat pipe The cooling effect that the difference of the condensation temperature in loop is reached can meet the holding of the predetermined temperature of whole machine room, controller（7） Signal, close compressor are sent in good time（1）, but while open compressor inlet and gas outlet, by throttling arrangement（3）Aperture Reach maximum；Now cold-producing medium is in condenser（2）Condensation, enters under gravity evaporimeter after condensation heat release（4）, evaporation Condenser is returned after heat absorption（2）；

Whole system is run in the presence of the cold-producing medium power that suffered gravity and compressor are provided in conduit.

8. control method according to claim 7, it is characterised in that：In each mode, the system is also by adjusting Outdoor fan（5）To adjust condenser（2）Air quantity, the refrigerating capacity of unit is adjusted, be accurately controlled interior temperature.

9. control method according to claim 7, it is characterised in that：In each mode, the system is also by cooling Water loop water pump（5’）Rotating speed adjusting condenser（2）The water yield, the refrigerating capacity of unit is adjusted, be accurately controlled room Interior temperature.