阅读说明：本技术 大型电力电子设备高可靠性闭式风冷散热系统和散热方法 (High-reliability closed air-cooled heat dissipation system and heat dissipation method for large power electronic equipment ) 是由 黄清军 李波 谭艳军 朱思国 朱远 毛新果 于 2019-11-29 设计创作，主要内容包括：本发明公开了一种大型电力电子设备高可靠性闭式风冷散热系统和散热方法,包括有封闭式风冷型电力设备、送风道和回风道、换热风柜、制冷机组；换热风柜的出风口经送风道后与封闭式风冷型电力设备的进风口相连,换热风柜的进风口经回风道与封闭式风冷型电力设备的排风口相连；其中：换热风柜内部沿风流方向依次布置有排风阀门、混风阀门、新风阀门、滤网、初级换热器、次级换热器、风机墙；初级换热器和次级换热器分别与制冷机组相连,并将交换出的热量经制冷主机排到室外空气中。本发明的系统中实现了整个风道系统中驱动风机的冗余配置,可做到多个制冷源的多重冗余配置,实现了整个风冷散热系统的高可靠性,保障被冷却大型电力电子正常工作需求。(The invention discloses a high-reliability closed air-cooled heat dissipation system and a heat dissipation method for large-scale power electronic equipment, which comprise closed air-cooled power equipment, an air supply duct, an air return duct, a heat exchange air cabinet and a refrigerating unit, wherein the air supply duct is connected with the air return duct; the air outlet of the heat exchange air cabinet is connected with the air inlet of the closed air-cooled power equipment through the air supply duct, and the air inlet of the heat exchange air cabinet is connected with the air outlet of the closed air-cooled power equipment through the air return duct; wherein: an exhaust valve, an air mixing valve, a fresh air valve, a filter screen, a primary heat exchanger, a secondary heat exchanger and a fan wall are sequentially arranged in the heat exchange air cabinet along the air flow direction; the primary heat exchanger and the secondary heat exchanger are respectively connected with the refrigerating unit and discharge the exchanged heat to the outdoor air through the refrigerating main machine. The system of the invention realizes the redundant configuration of the driving fan in the whole air duct system, can realize the multiple redundant configuration of a plurality of refrigeration sources, realizes the high reliability of the whole air-cooling heat dissipation system, and ensures the normal working requirement of the cooled large-scale power electronics.)

1. A high-reliability closed air-cooled heat dissipation system for large-scale power electronic equipment comprises closed air-cooled power equipment, an air supply duct, an air return duct, a heat exchange air cabinet and a refrigerating unit; the air outlet of the heat exchange air cabinet is connected with the air inlet of the closed air-cooled power equipment through the air supply duct, and the air inlet of the heat exchange air cabinet is connected with the air outlet of the closed air-cooled power equipment through the air return duct; wherein: an exhaust valve, an air mixing valve, a fresh air valve, a filter screen, a primary heat exchanger, a secondary heat exchanger and a fan wall are sequentially arranged in the heat exchange air cabinet along the air flow direction; the primary heat exchanger and the secondary heat exchanger are respectively connected with the refrigerating unit and discharge the exchanged heat to the outdoor air through the refrigerating main machine.

2. The closed air-cooled heat dissipation system with high reliability for the large-scale power electronic equipment according to claim 1, wherein the heat exchange air cabinet is made of a metal material with a heat insulation layer to form a cabinet body shell, and an exhaust valve, a fresh air valve and a plurality of access doors are arranged on a side plate; the air mixing valve, the filter screen, the primary heat exchanger, the secondary heat exchanger and the fan wall are sequentially arranged in the heat exchange air cabinet along the air flow direction; wherein the exhaust valve, the fresh air valve and the air mixing valve can be electrically opened and closed; the fan wall is formed by connecting a plurality of small speed regulation fans in parallel, and each small fan is provided with a check valve to prevent air from reversely flowing between the small speed regulation fans.

3. The high-reliability closed air-cooled heat dissipation system of large-scale power electronic equipment according to claim 2, wherein the fan wall is composed of 6 speed-adjustable fans which are spatially arranged in parallel, and the electric control signals of each fan are connected in parallel.

4. The closed air-cooled heat dissipation system with high reliability for large-scale power electronic equipment according to claim 2, wherein the air supply duct and the air return duct are both welded into metal ducts by adopting steel plates, and are externally wrapped with plastic heat insulation materials to inhibit heat exchange between the air ducts and outdoor air.

5. The high-reliability closed type air-cooled heat dissipation system for large-scale power electronic equipment according to claim 2, wherein the refrigerating unit consists of two refrigerating main machines which work independently; the refrigerants of the two refrigeration main machines are respectively connected with a primary heat exchanger and a secondary heat exchanger in the heat exchange air cabinet; the main refrigerating machine is an evaporation-condensation type direct expansion unit.

6. The high-reliability closed type air-cooled heat dissipation system for power electronic equipment according to claim 2, wherein the regulation and control of the fan, the air valve and the refrigerating unit are independent of each other.

7. The method for dissipating heat of the power electronic equipment by adopting the high-reliability closed air-cooled heat dissipation system of the large power electronic equipment according to any one of claims 1 to 6, comprising the following steps of:

under the normal operating condition: the refrigeration main machine is used for refrigerating, the hot air in the primary heat exchanger and the secondary heat exchanger is cooled, then the cold air enters an air inlet of the large-scale power equipment through an air supply duct by constant air quantity to cool the large-scale power equipment, return air is formed at the air outlet, and the return air enters the air inlet of the heat exchange air cabinet through a return air duct; when the return air temperature of the air inlet is lower than a set high-temperature protection value, the exhaust valve and the fresh air valve are closed, the air mixing valve is opened, a closed circulating air cooling system is formed, the return air passes through the air mixing valve and the filter screen, then passes through the primary heat exchanger and the secondary heat exchanger in sequence, forms cold air again and enters the next circulation; when the air return temperature of the air inlet is not lower than the set high-temperature protection value, the exhaust valve is opened, the high-temperature return air is exhausted out of the pipeline, the air mixing valve is closed, the fresh air valve is opened, fresh air with lower temperature is introduced from the outside, and the low-temperature fresh air passes through the primary heat exchanger and the secondary heat exchanger after being filtered by the filter screen to form cold air and enters the next cycle.

8. The heat dissipation method of claim 7, wherein the fan wall operates in a constant air volume mode, and when each fan operates normally, the fans are connected in parallel to balance the same output; when some fans are in fault or overhauled and shut down, the total air volume is kept unchanged by increasing the output of the rest fans.

9. The heat dissipation method as claimed in claim 7, wherein the operation state of the refrigeration hosts is regulated according to the outlet air temperature of the air-conditioning cabinet, and the start, stop and output of the two refrigeration hosts are adjusted in real time to enable the outlet air temperature of the air conditioner to track the target value of the set air temperature.

Technical Field

The invention belongs to the field of electrical engineering, and particularly relates to a high-reliability closed air-cooled heat dissipation system and a heat dissipation method for large-scale power electronic equipment.

Background

In the last two decades, with the large-scale access of new energy resources such as wind power, photovoltaic and the like, a power system faces new technical challenges in the links of power generation, power transmission, power generation and the like, and large-scale power electronic equipment is an effective means for solving the problems, and large-scale power electronic systems such as a Flexible Alternating Current Transmission System (FACTS), ultra-high voltage direct current transmission (UHVDC), Flexible direct current transmission (flex-HVDC) and the like are rapidly developed.

Due to the inherent characteristics of semiconductor power devices, power electronic equipment generates about 1% of active loss when in operation, for example, the rated heating capacity of the SVG of 1 station 100Mvar is up to 1000 kW. According to the statistics of reliability research reports of a power electronic system, a power device is a component with the highest failure rate in a converter system and accounts for about 34%; among the various failure factors, about 55% of power electronic system failures are mainly induced by temperature factors. For large-scale power electronic equipment with capacity variation of hundreds of megavolt-ampere, the large-scale power electronic equipment has the advantages of large heating total amount, high heating density, long-term continuous operation under a high-pressure working condition and strict requirements on the efficiency and the reliability of a heat dissipation system. At present, high-capacity power electronic equipment generally adopts a water cooling mode with higher heat dissipation efficiency to dissipate heat of devices. However, in the water cooling mode, the water inlet and outlet pipe joints of the large power electronic equipment are numerous, so that a large water leakage risk exists, once water leakage occurs, an insulation fault is caused, the reliability is poor, and the reliability of the power electronic system device is seriously influenced. In view of this, it is preferred to use air cooling to dissipate heat from the device.

However, in the existing air cooling system for large-scale power electronic devices such as the STATCOM, fans of the existing air cooling system generally adopt a mode of arranging a heat dissipation fan on each power cabinet body, and are limited by the cabinet body structure and the air path structure, the fans cannot realize redundant configuration, and once any one fan fails, partial power components are overheated due to air cut, so that the whole power electronic system fails and stops running due to air cooling. In addition, the refrigeration of the air conditioner unit is realized by adopting an open air cooling mode or an air conditioning unit refrigeration mode, the open air cooling mode is realized by directly utilizing outdoor fresh air for refrigeration, the problems of dust accumulation, equipment internal condensation and the like caused by the fact that dust in radiating air accumulates in an air duct and particularly on cooled equipment for a long time exist, and the safe operation of the cooled equipment is seriously influenced; when the air conditioning unit refrigerates, the cooled equipment also needs to be stopped for maintenance once the air conditioning unit fails and stops running, and the reliability is not high.

Disclosure of Invention

The invention aims to provide a high-reliability closed air-cooled heat dissipation system and a heat dissipation method for large-scale power electronic equipment with high reliability.

The invention relates to a high-reliability closed air-cooled heat dissipation system for large-scale power electronic equipment, which comprises closed air-cooled power equipment, an air supply duct, an air return duct, a heat exchange air cabinet and a refrigerating unit, wherein the closed air-cooled power equipment is connected with the air supply duct; the air outlet of the heat exchange air cabinet is connected with the air inlet of the closed air-cooled power equipment through the air supply duct, and the air inlet of the heat exchange air cabinet is connected with the air outlet of the closed air-cooled power equipment through the air return duct; wherein: an exhaust valve, an air mixing valve, a fresh air valve, a filter screen, a primary heat exchanger, a secondary heat exchanger and a fan wall are sequentially arranged in the heat exchange air cabinet along the air flow direction; the primary heat exchanger and the secondary heat exchanger are respectively connected with the refrigerating unit and discharge the exchanged heat to the outdoor air through the refrigerating main machine.

The heat exchange air cabinet is characterized in that a cabinet body shell is made of metal materials with heat insulation layers, and an exhaust valve, a fresh air valve and a plurality of access doors are arranged on a side plate; the air mixing valve, the filter screen, the primary heat exchanger, the secondary heat exchanger and the fan wall are sequentially arranged in the heat exchange air cabinet along the air flow direction; wherein the exhaust valve, the fresh air valve and the air mixing valve can be electrically opened and closed.

The fan wall is formed by connecting a plurality of small speed regulation fans in parallel, and each small fan is provided with a check valve to prevent air from reversely flowing between the small speed regulation fans.

Preferably, the fan wall is composed of 6 speed-adjustable fans which are spatially arranged in parallel, and the electric control signals of each fan are connected in parallel.

The air supply duct and the air return duct are both welded into a metal pipeline by adopting steel plates, and plastic heat insulation materials are wrapped outside the metal pipeline to inhibit heat exchange between the air duct and outdoor air.

The refrigerating unit consists of two refrigerating main machines which work independently; the refrigerants of the two refrigeration main machines are respectively connected with the primary heat exchanger and the secondary heat exchanger in the heat exchange air cabinet.

The main refrigerating machine is an evaporation-condensation type direct expansion unit.

The regulation and control of the fan, the air valve and the refrigerating unit are mutually independent.

The method for radiating the power electronic equipment by adopting the high-reliability closed air-cooled radiating system of the large power electronic equipment comprises the following steps:

under the normal operating condition: the refrigeration main machine is used for refrigerating, the hot air in the primary heat exchanger and the secondary heat exchanger is cooled, then the cold air enters an air inlet of the large-scale power equipment through an air supply duct by constant air quantity to cool the large-scale power equipment, return air is formed at the air outlet, and the return air enters the air inlet of the heat exchange air cabinet through a return air duct; when the return air temperature of the air inlet is lower than a set high-temperature protection value, the exhaust valve and the fresh air valve are closed, the air mixing valve is opened, a closed circulating air cooling system is formed, the return air passes through the air mixing valve and the filter screen, then passes through the primary heat exchanger and the secondary heat exchanger in sequence, forms cold air again and enters the next circulation; when the air return temperature of the air inlet is not lower than the set high-temperature protection value, opening an exhaust valve, discharging high-temperature return air out of the pipeline, closing an air mixing valve, opening a fresh air valve, introducing fresh air with lower temperature from the outside, filtering the low-temperature fresh air by a filter screen, passing through a primary heat exchanger and a secondary heat exchanger in sequence to form cold air, and entering the next cycle;

the fan wall works in a constant air volume working mode, and when each fan works normally, all the fans are connected in parallel to balance the same output; when some fans are in fault or overhauled and shut down, the total air volume is kept unchanged by increasing the output of the rest fans.

The running state of the refrigeration main machines is regulated and controlled according to the air outlet temperature of the air-conditioning air cabinet, and the starting, stopping and output of the two refrigeration main machines are regulated in real time to enable the air outlet temperature of the air conditioner to track the set air temperature target value.

The invention provides a high-reliability closed air-cooled heat dissipation system of large-scale power electronic equipment, which has multiple optional working conditions in the operation process, and each vulnerable part is provided with a standby component or a standby working mode for ensuring normal air-cooled heat dissipation, so that the normal heat dissipation requirement of the cooled power equipment can be ensured. Compared with the prior art, the invention has the following advantages:

1) the cooled equipment mainly works under the working condition of closed air cooling heat dissipation, and can effectively prevent impurities such as dust, saline and alkaline, catkin and the like in outdoor air from entering and accumulating, so that the reliability of an air cooling system and the cooled equipment and the adaptability to the external severe environment are improved. Although a standby working mode of radiating heat by outdoor fresh air under partial working conditions also exists, the standby working mode is only operated for a short time as an emergency working condition, and the problem of reliability caused by dust deposition can be solved.

2) The air-cooled heat dissipation device has multiple working conditions such as air-conditioning refrigeration closed air-cooled heat dissipation, fresh air natural air-cooled heat dissipation, combined air-cooled heat dissipation of the fresh air and the refrigerating unit and the like, and the heat dissipation requirement of cooled power equipment can be met under each working condition. And each mode can be automatically switched, and when one mode fails due to reasons, the other mode can be automatically switched, so that the normal heat dissipation requirement of the cooled equipment is guaranteed. The system not only realizes the N +1 redundant configuration of the driving fan in the whole air duct system, but also can realize the multiple redundant configuration of a plurality of refrigeration sources, thereby realizing the high reliability of the whole air cooling heat dissipation system and ensuring the normal working requirement of the cooled large-scale power electronics.

3) The control is simple. The three types of equipment, namely the fan, the air valve and the refrigerating unit, which need to be regulated and controlled in the system are mutually independent in regulation and control, and the respective control logics are very simple, so that not only is a complex control algorithm avoided, but also no dead angle in control can be ensured, and the on-site implementation is easy.

Drawings

Fig. 1 is a structural diagram of a high-reliability closed air-cooled heat dissipation system of a large-scale power electronic device according to the present invention;

wherein: 1-cooled power equipment, 2-air supply duct, 3-air return duct, 4-heat exchange air cabinet, 5-refrigerating unit, 41-exhaust valve, 42-air mixing valve, 43-fresh air valve, 44-filter screen, 45-primary heat exchanger, 46-secondary heat exchanger and 47-fan wall.

Detailed Description

Fig. 1 shows a system structure of a high-reliability closed air-cooled heat dissipation system for large-scale power electronic equipment according to the present invention. The following will be specifically described in conjunction with the heat dissipation requirements of an air-cooled SVG;

the cooled power equipment 1 is a STATCOM with 100Mvar, the STATCOM adopts an air-cooled radiator, and a plurality of air-cooled power modules are arranged in each power cabinet; each power cabinet body is closed, the air inlets of the power cabinet bodies are connected in parallel and then connected to the air supply duct 2, and the air outlets of the power cabinet bodies are connected in parallel and then connected to the air return duct 3.

The other end of the air return duct 3 is communicated with an air inlet of the heat exchange air cabinet 4, and an air outlet of the heat exchange air cabinet 4 is communicated with the air supply duct 2. The air supply duct 2 and the air return duct 3 are both welded into metal pipes by adopting steel plates, and plastic heat insulation materials are wrapped outside the metal pipes to inhibit heat exchange between the air ducts and outdoor air.

The heat exchange air cabinet 4 is made of metal material with a heat insulation layer to form a cabinet body shell, and an exhaust valve 41, an air mixing valve 42, a fresh air valve 43, a filter screen 44, a primary heat exchanger 45, a secondary heat exchanger 46 and a fan wall 47 are sequentially arranged inside the heat exchange air cabinet 4 along the air flow direction. The air mixing valve 42, the filter screen 44, the primary heat exchanger 45, the secondary heat exchanger 46 and the fan wall 47 are arranged on the channel of the heat exchange air cabinet 4 along the air flow direction. The exhaust valve 41, the fresh air valve 42 and the air mixing valve 43 can be electrically closed, the fan wall 47 is composed of 6 speed-adjustable fans which are spatially arranged in parallel, electrical control signals of all the fans are connected in parallel, the fan set parameters are configured according to rated air volume which is 1.2 times of the air volume when the fan set runs in a full-load mode under a closed running mode, and the exhaust valve, the fresh air valve and the air mixing valve can be electrically opened and closed.

The refrigerating unit 5 is composed of two evaporation-condensation type direct-expansion units which work independently, refrigerants of the two evaporation-condensation type direct-expansion units are respectively connected with a primary heat exchanger 45 and a secondary heat exchanger 46 in the heat exchange air cabinet 4, the refrigerants exchange heat with air in the air-conditioning air cabinet, and meanwhile heat exchanged in the heat exchangers is diffused into outdoor air through the refrigerating unit 5. The rated refrigerating capacities of the two direct expansion units are respectively designed according to 40% and 80% of the rated refrigerating capacity of the cooled equipment to ensure that the total refrigerating capacity is slightly higher than the rated refrigerating capacity of the cooled equipment, so that the heat dissipation requirement of the cooled equipment is economically met, and a certain allowance is provided.

In the system, three types of equipment, namely a fan, a refrigerating unit and an air valve, are regulated and controlled respectively:

1) controlling a fan: the fan wall 47 is always opened during the operation of the cooling and heat dissipating system, that is, the fan is opened before the cooled device is started until the cooled device stops working and the air-cooled heat dissipating system is closed, and during the operation, no matter how the working state of the refrigeration main machine and the valve is, the fan wall 47 is always opened to drive air to circulate along the fan wall, the air supply duct, the cooled closed air-cooled device and the air return duct. And the fan wall 47 works in a constant air volume working mode, that is, the air speed in the air duct is detected to calculate the total air volume of the system, and the output of each fan in the fan wall 47 is regulated to enable the detected air volume of the air duct to track the set air volume control target. When each fan works normally, the regulation and control instructions of each fan are the same, so that the fans are connected in parallel to balance the same output; when some fans are in fault or overhauled and shut down, the rest fans are added to enable the total air volume to track the air volume control target. Therefore, the redundant configuration of the driving fan in the whole air duct system can be realized, and the air cannot be easily stopped or the air quantity is insufficient.

2) Controlling an air valve: the exhaust valve 41, the air mixing valve 42 and the fresh air valve 43 in the system are collectively called as air valves, and the operation state of the air valves is regulated and controlled only according to the temperature of inlet air and outlet air. Under normal operating conditions, exhaust valve 41 and new trend valve 43 all close and mix the blast gate 42 and open, let the hot-blast mixed blast gate 42, filter screen 44 and the fan wall 47 direction circulation in the air-conditioning wind cabinet of returning back to the wind channel, through the air supply wind channel again, by cooling electric power equipment back get back to the wind channel to constitute closed circulation wind channel, make whole air cooling system be closed circulation air cooling system. When the return air temperature is detected to exceed a certain set high-temperature protection value (the high-temperature protection value can be set according to the upper limit of the outlet air temperature when the refrigerating unit normally works and the inlet and outlet air temperature difference when the cooled equipment runs fully), which means that the refrigerating capacity of the current refrigerating unit 5 is insufficient to take away the heat productivity of the power equipment 1, the exhaust valve 41 and the fresh air valve 43 are opened, the air mixing valve 42 is closed, the fresh air with lower outdoor temperature is introduced to carry out air cooling and heat dissipation on the cooled equipment 1, and meanwhile, the hot air in the return air duct is discharged to the outside through the exhaust valve 41; when the return air temperature is lower than the high-temperature protection value, the exhaust valve 41 and the fresh air valve 43 are closed, and the air mixing valve 42 is opened to recover to the closed circulation air cooling mode.

3) The refrigerating unit 5 controls: the running states of the two refrigeration hosts are regulated and controlled according to the air outlet temperature of the air conditioner air cabinet, the air temperature instruction values of the two refrigeration hosts are the same and are equal to the air outlet temperature set value, and loading and unloading and start-stop control are carried out according to the deviation of the air outlet temperature and the set value.

(A) The start-stop control logic of the secondary refrigeration main machine (the refrigeration main machine connected with the secondary heat exchanger) is as follows: when the outlet air temperature is higher than the set value and higher than 4 ℃, sending a starting instruction to the secondary refrigerating unit (if the secondary refrigerating unit is started, the starting state is kept, and if the secondary refrigerating unit is in the shutdown state, the secondary refrigerating unit is started); when the outlet air temperature is less than the set value minus 4 ℃, a shutdown instruction is sent to the secondary refrigerating unit (if the secondary refrigerating unit is in a shutdown state, the shutdown state is kept, and if the secondary refrigerating unit is in a startup state, the shutdown is carried out.

(B) The starting and stopping control logic of the primary refrigeration main machine (the refrigeration main machine connected with the primary heat exchanger) is as follows: when the outlet air temperature is higher than the set value and higher than 3 ℃, sending a starting instruction to the primary refrigerating unit (if the primary refrigerating unit is started at the moment, keeping the starting state, and if the primary refrigerating unit is in the shutdown state, starting the primary refrigerating unit); and when the outlet air temperature is less than the set value minus 3 ℃, sending a shutdown instruction to the primary refrigerating unit (if the primary refrigerating unit is in a shutdown state, keeping the shutdown state, and if the primary refrigerating unit is in a startup state, shutting down the primary refrigerating unit.

(C) The load and load reduction control precision of the primary refrigeration host machine is controlled according to 1 ℃, namely when the actual air outlet temperature of the air cabinet is higher than a set value plus 1 ℃, the primary refrigerator is gradually loaded to increase the refrigerating capacity until the air cabinet is fully loaded, when the actual air outlet temperature of the air cabinet is lower than a set value minus 1 ℃, the primary refrigerator is gradually unloaded until the load is minimum, and when the actual air outlet temperature of the air cabinet is (the set value minus 1 ℃, the set value plus 1 ℃), neither loading nor unloading is performed.

(D) The load and load reduction control precision of the secondary refrigeration main machine is controlled according to 2 ℃, namely when the actual air outlet temperature of the air cabinet is higher than a set value plus 2 ℃, the secondary refrigerator is gradually loaded to increase the refrigerating capacity until the air cabinet is fully loaded, when the actual air outlet temperature of the air cabinet is lower than a set value minus 2 ℃, the secondary refrigerator is gradually unloaded until the load is the minimum load, and when the actual air outlet temperature of the air cabinet is (the set value minus 2 ℃, the set value plus 2 ℃), neither the secondary refrigerator is loaded nor unloaded.

Under the control logic, the control logic of each refrigeration host is similar to the control logic of a conventional single running air conditioning unit, so that a mature air conditioning unit control program is conveniently utilized; the operation control mode of the two refrigeration hosts realizes the coordination of the two refrigeration hosts only through parameter values, and the complex judgment caused by reading the state of the other refrigeration host during the coordination control of the two refrigeration hosts is avoided. When the configuration result is obtained, the unit control program is convenient to realize on site, is not easy to make mistakes and has high reliability.

The fan, damper and refrigeration unit are all commercially available and have separate regulation systems.

The above description is only one embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments, and all technical solutions belonging to the idea of the present invention belong to the protection scope of the present invention. It should be noted that modifications and adaptations to those skilled in the art may occur to persons skilled in the art without departing from the spirit and scope of the present invention.