Patent Description:
In recent years, a wind power generator set has gradually developed towards high power density, a loss of the set itself has increased accordingly, and the number of components that need to be cooled has also increased. A generators, a shaft system, a pitch, a nacelle cabinet, a nacelle, a converter cabinet, a transformer and other heating components need to undergo necessary heat dissipation and cooling treatment to achieve a normal operation of each heating component. Especially for an offshore wind power generator set, components are arranged in an E-TOP structure of the nacelle, resulting in more and more complex arrangement and layout of the overall cooling system of the set in the nacelle. Therefore, it is necessary to design a more compact cooling system structural layout research direction in a limited space of the nacelle. <CIT> discloses a system to cool the air inside a nacelle and the heat generating components housed in the nacelle of an offshore wind turbine is presented. An upper cooling circuit is disposed in the nacelle. A reservoir is disposed below the upper cooling circuit and has a lid that freely rotates about a vertical axis of the reservoir along with an inlet and an outlet pipe of the upper cooling circuit as the nacelle yaws, the vertical axis of the reservoir being coincident with a yaw axis of the nacelle. A lower cooling circuit is disposed below the reservoir. Coolant is circulated through the upper cooling circuit using a cooling pump disposed between the nacelle and the upper cooling circuit. The upper cooling circuit carries heat from the heat generating components and from the air inside the nacelle to the reservoir. The lower cooling circuit carries heat from the reservoir to the bottom of the tower and dissipates the heat to the sea water through a heat exchanger that is cooled by the sea water.

<CIT> discloses a cooling system for cooling multiple heat generation parts. The cooling system includes multiple first heat exchange modules connected in parallel for heat exchange with the heat generation parts, and a second heat exchange module for heat exchange with the first heat exchange modules and external environments. The cooling system of the multiple heat generation parts are integrated; the initial investment of equipment is reduced, and the operation cost is saved; the overall planning of an experimental center is convenient; and the space and land sources are saved. First heat exchange amounts of all the first heat exchange modules are metered through a heat metering module to obtain heat generation amounts of the heating parts corresponding to the first heat exchange modules; and the second heat exchange module can adjust the working state through the heat generation amount of each heating part, so that each heat generation part can be cooled more precisely, and the normal operation of each heat generation part can be guaranteed.

<CIT> discloses a cooling system of a wind power generator set belonging to a technical field of wind power generation. The purpose is to improve an unreasonable setup of a cool pipeline and parts in the wind generator cooling system in the prior art. There are many intersecting places in coolant liquid circulation pipelines, the best radiating effect cannot be obtained in the in -service use. A cooling system includes a pump station, a first heat exchanger, a second heat exchanger, a third heat exchanger, a water collector and a water distributor. The third heat exchanger is provided outside of a nacelle of the wind power generator set. The first heat exchanger is provided on the top of the generator of the wind power generator set. The second heat exchanger is provided above the gear box of the wind power generator set. The water outlet of the third heat exchanger is communicated with the water inlet of the pump station, the water outlet of the pump station is communicated with the water inlet of the water distributor. The water distributor and the water collector control the water of the second heat exchanger and the third heat exchanger. The cooling system of a wind power generator disclosed in the utility model is especially suitable to be installed on and used in the large -scale wind power generator with relatively high requirements on the heat dissipation.

An object of the present disclosure is to provide a cooling system and a wind power generator set. The cooling system can control multiple cooling circuits is in a centralized manner, simplifying a line configuration and reducing the number of heat dissipation components.

In an aspect, the present disclosure provides a cooling system, comprising: a first cooling circuit for cooling a first heating component, a second cooling circuit for cooling a second heating component, a third cooling circuit for cooling a third heating component, a fourth cooling circuit for cooling a fourth heating component, a pump station unit and a heat dissipation unit; wherein the pump station unit comprises a pump group, a water distributor and a water collector, a main water supply pipe is arranged between the pump group and the water distributor, and a main water return pipe is arranged between the pump group and the water collector; the pump group provides cooling medium for the first cooling circuit, the second cooling circuit, the third cooling circuit and the fourth cooling circuit via the water distributor; the first cooling circuit is directly communicated with the water distributor and the water collector, and the second cooling circuit, the third cooling circuit, and the fourth cooling circuit are respectively connected to the water collector via the heat dissipation unit, wherein the first heating component has the smallest heat generation amount, the third heating component has the largest heat generation amount, and each of the second heat generating component and the fourth heat generating component has a heat generation amount between the heat generation amount of the first heating component and the heat generation amount of the third heating component.

In another aspect, the present disclosure provides a wind power generator set, comprising: a first heating component, comprising at least one of a shaft system, a cable, a nacelle, a pitch mechanism, a nacelle cabinet, and a nacelle base; a second heating component, comprising a converter; a third heating component, comprising a generator; a fourth heating component, comprising a transformer; and the above-mentioned cooling system.

The cooling system provided by the present disclosure integrates the first cooling circuit, the second cooling circuit, the third cooling circuit and the fourth cooling circuit corresponding to respective heating components into one system, and the pump station unit is used as a core power unit of the entire cooling system powers to provide the power for the entire cooling system. As a cooling load undertaken by the first cooling circuit is small, its inlet and outlet are respectively directly connected to the pump station unit through a short circuit, which simplifies a line layout without causing a great impact on a rise of a temperature of the cooling medium in the entire system. Large losses appear in the second cooling circuit, the third cooling circuit, and the fourth cooling circuit. The temperature of the cooling medium pumped from the pump station unit rises after passing through the above three cooling circuits, then enters the heat dissipation unit via which the temperature of the cooling medium drops, and enters the pump station unit again to form a closed-circuit cycle, simplifying a line configuration, reducing the number of heating components, and improving a utilization rate of the cooling capacity of the system. In addition, a wind turbine generator set provided by the present disclosure adopts the aforementioned cooling system, which can effectively calculate a system loss and a heat transfer direction during the operation of the set, and at the same time, explores a more reasonable selection of components to provide sufficient statistical basis for a subsequent evaluation of the reliability of wind power generator set combined with an ambient temperature.

The present disclosure can be better understood from the following description of specific embodiments of the present disclosure in conjunction with accompanying drawings. Other features, obj ects and advantages of the present disclosure will become apparent by the following detailed description of non-limiting embodiments with reference to the accompanying drawings. The same or similar reference numbers refer to the same or similar features.

Features and exemplary embodiments of various aspects of the present disclosure are described in detail below. Numerous specific details are disclosed in the following detailed description to provide a thorough understanding of the present disclosure. However, it will be apparent to those skilled in the art that the present disclosure may be practiced without some of these specific details. The following description of embodiments is merely to provide a better understanding of the present disclosure by illustrating examples of the present disclosure. The present disclosure is in no way limited to any specific configurations and algorithms set forth below, but covers any modifications, substitutions and improvements of elements, components and algorithms without departing from the scope of protection sought which is defined by the appended claims. In the drawings and the following description, well-known structures and techniques have not been shown in order to avoid unnecessarily obscuring the present disclosure.

With a rapid development of wind power generator set, a single-unit capacity of the set is increasing. On the one hand, a loss of the set itself increases, and on the other hand, the number of components that need to be cooled also increases. Especially with a development of a large-capacity offshore set, the E-TOP layout structure (generator, shaft system, pitch system, nacelle cabinet, converter cabinet, transformer and other heating components are all arranged in the nacelle) has an advantage of significantly improving the overall performance relative to environmental factors at sea. But when these heating components are arranged in the nacelle, they all require independent heat dissipation and cooling treatment, and all cooling subsystems are arranged in the nacelle, resulting in more and more components in the nacelle and an increasingly complex layout. In view of different control strategies, processes and layout positions of each heating component, lines of each cooling subsystem are complicated, the number of radiators increases, and the control logic is complicated, which leads to an increase in a failure rate of the system. The overall layout and structure of the cooling subsystem of each heating component are optimized to achieve centralized cooling.

The present disclosure aims to construct a centralized cooling system for a wind power generator set, which is especially suitable for a permanent magnet direct-drive wind power generator set with a high-power offshore E-TOP layout. For the set with no E-TOP layout (that is, the main heating components are not all located in the nacelle), if a length cost and a layout complexity of a line are not considered, the centralized cooling system of the present disclosure can also be used. That is, according to an actual position of respective heating components, the same layout idea can be adopted to layout respective cooling subsystems, thereby optimizing the layout of the cooling subsystems of the heating components as a whole. For a better understanding of the present disclosure, the cooling system and the wind power generator set according to embodiments of the present disclosure will be described in detail below with reference to <FIG>.

Referring to <FIG>, an embodiment of the present disclosure provides a wind power generator set, including: a first heating component <NUM>, a second heating component <NUM>, a third heating component <NUM>, a fourth heating component <NUM>, and a cooling system.

The first heating component <NUM> is a combination of components that generate a relatively less amount of heat, and its heat dissipation loss is also small. The heat-dissipating subsystems of all the heating components can be integrated into one cooling circuit or several cooling branches in an integrated manner, to achieve the heat dissipation requirements of heating components. Optionally, the first heating component <NUM> may include at least one of a shaft system, a cable, a pitch, a nacelle, a nacelle cabinet, and a nacelle base.

The second heating component <NUM> is a combination of components that generate a relatively large amount of heat, and its corresponding heat dissipation loss requirements are also relatively high. Optionally, the second heat generating component <NUM> includes a converter. In addition, the second heating component <NUM> is generally required to be maintained a minimum temperature, and an increase or decrease of its heat dissipation loss is proportional to the heat dissipation loss of the third heating component <NUM> (such as a generator), that is, they operate in opposite directions.

The third heating component <NUM> is a combination of components that generate the largest amount of heat, and its corresponding heat dissipation loss requirement is also the highest. Optionally, the third heating component <NUM> may include a generator. In addition, the third heating component <NUM>, taking the generator as an example, not only generates a large amount of heat, but also provides the waste heat to other heating components in a low temperature environment, so as to meet the minimum temperature operation requirements of other heating components in a low temperature environment.

The fourth heating component <NUM> is a combination of components that generate a relatively large amount of heat, and its corresponding heat dissipation loss requirement is also relatively high. Optionally, the fourth heating component <NUM> includes a transformer. Moreover, the increase or decrease of the heat dissipation loss of the fourth heating component <NUM> is proportional to the heat dissipation loss of the third heating component <NUM>, taking the generator as an example, that is, they operate in opposite directions.

It should be noted that in the present disclosure, in actual operation and design, according to a specific number of each heating component and different cooling forms and cooling requirements, settings and coupling settings of all the cooling circuits are similar to form an integral cooling system. For ease of description, an embodiment of the present disclosure uses the first cooling circuit <NUM> for cooling the first heating component <NUM> (i.e., a small-capacity cooling system, such as a nacelle cooling system), the second cooling circuit <NUM> for cooling the second heating component <NUM> (i.e., a converter cooling system), the third cooling circuit <NUM> for cooling the third heating component <NUM> (i.e., a generator cooling system), and the fourth cooling circuit <NUM> for cooling the fourth heating component <NUM> (i.e., a transformer cooling system) as an example.

The cooling system provided by an embodiment of the present disclosure includes: the first cooling circuit <NUM> for cooling the first heating component <NUM>, the second cooling circuit <NUM> for cooling the second heating component <NUM>, and the third heating component <NUM> for cooling the third cooling circuit <NUM>, the fourth cooling circuit <NUM> for cooling the fourth heating component <NUM>, the pump station unit <NUM> and the heat dissipation unit <NUM>. The first heating component <NUM> has the smallest heat generation amount, the third heating component <NUM> has the largest heat generation amount, and each of heat generation amount of the second heating component <NUM> and the fourth heating component <NUM> is between that of the first heating component <NUM> and that of the third heating component <NUM>.

As the core power unit of the entire cooling system, the pump station unit <NUM> provides power for the entire cooling system. The pump station unit <NUM> includes a pump group <NUM>, a water distributor <NUM> and a water collector <NUM>. A main water supply pipe <NUM> is arranged between the pump group <NUM> and the water distributor <NUM>, and a main water return pipe <NUM> is arranged between the pump group <NUM> and the water collector <NUM>.

The pump group <NUM> provides cooling medium for the first cooling circuit <NUM>, the second cooling circuit <NUM>, the third cooling circuit <NUM> and the fourth cooling circuit <NUM> via the water distributor <NUM>. The cooling medium may be a liquid medium, such as water, oil, or the like. The first cooling circuit <NUM> is directly communicated with the water collector <NUM>, and the second cooling circuit <NUM>, the third cooling circuit <NUM>, and the fourth cooling circuit <NUM> are respectively communicated with the water collector <NUM> via the heat dissipation unit <NUM>.

The pump station unit <NUM> is provided with the water distributor <NUM> on the main water supply pipe <NUM> and the water collector <NUM> on the main water return pipe <NUM> to ensure a stability of the water supply of the system. The cooling medium is provided to each heating component via the pump group <NUM> and a water supply line on the water distributor <NUM>, and the water of the first cooling circuit <NUM>, the second cooling circuit <NUM>, the third cooling circuit <NUM>, and the fourth cooling circuit <NUM> is returned via the water return line on the water collector <NUM>.

In the cooling system provided by the embodiment of the present disclosure, the first cooling circuit <NUM>, the second cooling circuit <NUM>, the third cooling circuit <NUM> and the fourth cooling circuit <NUM> corresponding to respective heating components are integrated into one system, and as the core power unit of the entire cooling system, the pump station unit <NUM> provides power for the entire cooling system. As a cooling load undertaken by the first cooling circuit <NUM> is small, its inlet and outlet are respectively directly connected to the pump station unit <NUM> through a short circuit, which simplifies a line layout without causing a great impact on a rise of a temperature of the cooling medium in the entire system. Large losses appear in the second cooling circuit <NUM>, the third cooling circuit <NUM>, and the fourth cooling circuit <NUM>. The temperature of the cooling medium pumped from the pump station unit <NUM> rises after passing through the above three cooling circuits, then enters the heat dissipation unit <NUM> via which the temperature of the cooling medium drops, and enters the pump station unit <NUM> again to form a closed-circuit cycle, simplifying a line configuration, reducing the number of heating components, and improving a utilization rate of the cooling capacity of the system.

<FIG> shows a specific structure of the pump station unit <NUM>. The pump station unit <NUM> includes the pump group <NUM>, various functional valves, various sensors, a pressure stabilizing device and a filter, so as to realize a normal, stable and maintainable operation of the entire cooling system. The pump group <NUM> may include one pump body Pu or at least two pump bodies Pu arranged in parallel. When the pump group <NUM> includes at least two pump bodies Pu arranged in parallel, the at least two pump bodies Pu can be used for parallel operation, or in a form of partial operation and partial backup. According to a comprehensive consideration of a space layout size, system capacity, reliability, cost-effectiveness and other factors, an energy-saving and fault-tolerant operation can be realized. That is, after one pump body Pu fails, the remaining pump body Pu can still meet all or more than <NUM>% of the performance of the system. At the same time, in order to further achieve the optimal energy efficiency of the system, the pump group <NUM> of each cooling subsystem S can adopt control methods such as fixed frequency operation, high and low speed operation, variable frequency operation, or fault-tolerant operation of at least two pump bodies, so as to meet a need of a cool load operation of the entire wind power generator set and improve the fault tolerance of the system and an effective energy saving strategy.

The pump body Pu is provided with an exhaust valve AV to exhaust gas during the operation of the system, thereby protecting a safe operation of the pump group <NUM>. An outlet of the pump body Pu is provided with a check valve SV to protect the pump body Pu. An inlet of the pump body Pu is provided with a pump body regulating valve PV When a leakage problem appears in any one of the pump bodies Pu, the corresponding pump body regulating valve PV is quickly closed. The corresponding pump body Pu is cut off via the check valve SV and the pump body regulating valve PV If the pump body Pu is in a form of a non-mechanical seal, the setting of the pump body regulating valve PV can be omitted.

Optionally, the inlet of the pump set <NUM> is provided with a filter Fi to ensure a cleanliness of the system. In addition, the filter Fi is provided with a drainage function and can be used as a local drainage point for the pump group <NUM>.

Optionally, the main water return pipe <NUM> is provided with the pressure stabilizing device SP, which can be used in a form of a high-level water tank or an expansion tank, to generate an alarm for the system when the pressure in the system fluctuations due to temperature changes to avoid a harm to the system. Optionally, the outlet of the pump group <NUM> is provided with a safety device SF to relieve pressure to achieve protection when the pressure in the system exceeds a certain value.

Optionally, the inlet and outlet of the pump group <NUM> are also provided with a main pressure monitoring device P. Optionally, the main pressure monitoring device P includes a pressure transmitter and a pressure display device. The main pressure transmitter is used for local and remote control of the operation of the system, and the main pressure display device is used for local injection and operation and maintenance observation.

Optionally, the main water supply pipe <NUM> and the main water return pipe <NUM> are respectively provided with a main valve V, and the water collector <NUM> and the water distributor <NUM> are respectively provided with a drain valve LV. Via the opening and closing of the main valve V, the water collector <NUM> and the water distributor <NUM> are cut out, thereby facilitating their replacement and maintenance.

Optionally, the inlet of the pump group <NUM> is provided with a main flow sensor FF, and the outlet of the pump group <NUM> is provided with a main temperature sensor TT. The main temperature sensor TT is used for taking a value of an inlet temperature of each cooling circuit. Combined with the temperature sensor provided on each of the cooling circuits and the cooling unit <NUM> and the flow sensor provided on each cooling branch, it is convenient to calculate the actual heat dissipation loss of each cooling circuit in a logic control process. Therefore, in combination with parameters such as ambient temperature, load of the set, flow rate of the system, etc., the entire internal logic relationship of each cooling circuit and the system is recorded, which is beneficial to the optimization of system control logic and the optimization of component selection.

The specific structure of each cooling circuit will be described in further detail below with reference to <FIG> and <FIG>.

<FIG> shows a specific structure of the first cooling circuit <NUM>. The first cooling circuit <NUM> is a small-capacity cooling system for cooling the first heating component <NUM>. The first heating component <NUM> includes at least one of a shaft system, a cable, a pitch, a nacelle, a nacelle cabinet, and a nacelle base. The first cooling circuit <NUM> includes a first fluid line, a plurality of first branch radiators 13a in parallel for cooling a plurality of first heating components <NUM>, and also includes a variety of functional valves and a variety of sensors to realize a normal, stable and maintainable operation of the first cooling circuit <NUM>.

The cooling medium flows into the first water supply pipe <NUM> via the water distributor <NUM> of the pump station unit <NUM>, and is transported to a plurality of first branch heat exchangers 13a in parallel. After exchanging heat with respective first heating component <NUM> in each branch heat exchanger, the cooling medium converges to the first water return pipe <NUM>, and then flows directly back to the pump station unit <NUM> via the water collector <NUM>.

Specifically, the first cooling circuit <NUM> includes a first fluid line, the first water supply pipe <NUM> of the first fluid line is communicated with the water distributor <NUM>, and the first water return pipe <NUM> of the first fluid line is communicated with the water collector <NUM>. The first fluid line is provided with a plurality of first fluid branches <NUM> corresponding to the plurality of first heating components <NUM> one-to-one. For example, some of the first fluid branches <NUM> are used to cool the shaft system, some of the first fluid branches <NUM> is used for cooling the pitch, and some of the first fluid branches <NUM> are used for cooling cables and the like. An end of each of the plurality of first fluid branches <NUM> converges to the first water supply pipe <NUM>, and the other end thereof converges to the first water return pipe <NUM>. The first water supply pipe <NUM> is communicated with the water distributor <NUM>, and the first water return pipe <NUM> is communicated with the water collector <NUM>.

Further, each of the first fluid branches <NUM> is provided with a first branch radiator 13a, and a first branch regulating valve VV1, a first branch temperature sensor TT1 and a branch flow sensor FF1 is located downstream of each first fluid branch <NUM>. Measured values of each of first branch temperature sensors TT1 and each of first branch flow sensors FF1 are monitored, according to a target temperature value of each first heating component <NUM>, a flow rate of a fluid branch <NUM> is adjusted by controlling an opening degree of each first branch regulating valve VV1.

Each first fluid branch <NUM> is provided with the first branch regulating valve VV1, which can adjust the flow rate of each first fluid branch <NUM> according to a load demand of each heating component, thereby dynamically adjusting a configuration of a cooling capacity of each heating component according to a change of an environmental boundary to achieve an adjustment of cooling capacity in other heat dissipation components.

In order to reduce the number of lines, the lines from the water distributor <NUM> of the pump station unit <NUM> are branched by collecting the first water supply pipe <NUM> to the vicinity of each first branch radiator 13a, and similarly, collecting and directly connecting the first water return pipe <NUM> to the water collector <NUM> and into the pump station unit <NUM>. Since each first branch radiator 13a of the first cooling circuit <NUM> bears a relatively small amount of loss. In order to simplify and shorten the line layout, the first water supply pipe <NUM> of the first cooling circuit <NUM> directly enters and exits the water collector <NUM>, the main water return pipe <NUM> directly enters and exits the water distributor <NUM>, avoiding too many other cooling circuits to the radiator and thereby effectively simplifying the line layout and optimizing the line arrangement.

Due to a continuous change of the ambient temperature, as well as a continuous load change of the set with a change of wind conditions, the first branch regulating valve VV1 on the first fluid branch <NUM> is dynamically adjusted according to different characteristics of respective first heating components <NUM> and by its temperature limit as the logical control object. The flow adjustment is used to provide sufficient cooling load for each first heating component and at the same time provide sufficient cooling load for other cooling circuits, or the load of the pump group <NUM> is adjusted to achieve energy saving of a system response.

Optionally, first flexible pipes <NUM> are respectively provided at the front and rear of the first branch radiator 13a to facilitate a connection between the line and the first branch radiator 13a and a vibration reduction of the equipment. The first branch temperature sensor TT1 is provided on the first fluid branch <NUM>, and combined with the main temperature sensor TT and the first branch flow sensor FF1 on the pump station unit <NUM>, the actual heat dissipation amount of each first fluid branch <NUM> can be obtained. Via data statistics and analysis, the logical relationship among environmental boundary, load of the set, opening of the regulating valve and other factors can be effectively obtained, which can effectively improve the optimization of each heat dissipation component and the logical control of the set.

Since corresponding components are arranged on each first fluid branch <NUM>, in order to reduce the influence on the whole system, at least one of the inlet and the outlet of the first water supply pipe <NUM>, the first water return pipe <NUM>, and each first branch radiator 13a is provided with a first valve V1. By an opening or closing of the first valve V1, the sensors and components on the first fluid branch <NUM> can be replaced and maintained.

Optionally, the first fluid line and at least one of first branch radiators 13a are provided with first drain valves LV1. By opening and closing a first drain valve LV1, the corresponding first fluid branch <NUM> can be cut off and the liquid can be discharged at a local position.

According to different radiating forms and different radiators, the first branch radiator 13a provided on the first fluid branch <NUM> may be in the form of air-water heat exchange, water-oil heat exchange or other forms. The first branch radiator 13a is provided with a first drain valve LV1, which facilitates partial drainage of the first branch radiator 13a and the first fluid branch <NUM>.

In order to prevent gas high collection at local points during a liquid injection process, optionally, each first branch radiator 13a is further provided with a first exhaust valve AV1 to facilitate local exhaust.

Optionally, a first pressure monitoring device P1 is respectively provided upstream and downstream of each first fluid branch <NUM>. Optionally, the first pressure monitoring device P1 includes a pressure transmitter and a pressure display device for remotely and locally monitoring the pressure change of the system.

<FIG> shows another specific structure of the first cooling circuit <NUM>. The first cooling circuit <NUM> is similar in structure to the first cooling circuit <NUM> shown in <FIG>, except that the cooling medium flows into each first fluid branch of the first cooling circuit <NUM> through the water distributor <NUM> of the pump station unit <NUM>, and after passing through the first branch heat exchangers 13a, flows back to the pump station unit <NUM> via the water collector <NUM> through respective independent lines to realize a closed-circuit circulation.

Specifically, the first fluid line includes a plurality of first fluid branches <NUM> corresponding to the plurality of first heating components <NUM> one-to-one, an end of each first fluid branch <NUM> is communicated with the water distributor <NUM>, and the other end of each first fluid branch <NUM> is communicated with the water collector <NUM>.

In this embodiment, the water distributor <NUM> of the pump station unit <NUM> is drawn out in the form of a branch pipe, and enters the water collector <NUM> also in the form of a branch pipe. A first drain valve LV1 is provided on each first fluid branch <NUM>, to meet a drainage of each first fluid branch <NUM>.

Referring again to <FIG>, the second cooling circuit <NUM> includes a second fluid line, and a second water supply pipe <NUM> of the second fluid line is communicated with the water distributor <NUM>. The third cooling circuit <NUM> includes a third fluid line, and the third water supply pipe <NUM> of the third fluid line is communicated with the water distributor <NUM>.

The fourth cooling circuit <NUM> includes a fourth fluid line, and the fourth water supply pipe <NUM> of the fourth fluid line is communicated with the water distributor <NUM>.

The second water return pipe <NUM> of the second fluid line, the third water return pipe <NUM> of the third fluid line, and the fourth water return pipe <NUM> of the fourth fluid line are respectively communicated with the water collector <NUM> via the heat dissipation unit <NUM>.

Further, the cooling system provided in the embodiment of the present disclosure further includes a heat exchanger <NUM>, a bypass <NUM> is provided on the third water supply pipe <NUM>, and the second water supply pipe <NUM> and the bypass <NUM> are thermally coupled and isolated from each other via the heat exchanger <NUM>.

Specifically, the bypass <NUM> is provided with a bypass regulating valve 33a, the heat exchanger <NUM> is configured to open the bypass regulating valve 33a when the temperature of the cooling medium of the second cooling circuit <NUM> is lower than a preset temperature, so that the cooling medium of the third cooling circuit <NUM> exchanges heat with the cooling medium of the second cooling circuit <NUM> via the bypass <NUM>. Therefore, under extremely low temperature conditions, via the heat exchanger <NUM>, the generator cooling system transfers a part of the heat load generated by the loss to the converter cooling system via the cooling medium of the bypass <NUM>, which not only makes reasonable use of the waste heat of the generator, and meet the minimum operating temperature requirements of heating components, such as the converter cooling system. Optionally, the heat exchanger <NUM> is a liquid-liquid two-way heat exchanger. The heat exchanger <NUM> includes a first heat conduction channel and a second heat conduction channel arranged at intervals. The first heat conduction channel includes a first inlet end 61a and a first outlet end 61b, and the second heat conduction channel includes a second inlet end 62a and a second outlet end 62b.

The second water supply pipe <NUM> includes a first section <NUM> and a second section <NUM>, the first section <NUM> is connected to the first inlet end 61a at its downstream, and the second section <NUM> is connected to the first outlet end 61b at its upstream.

The water supply bypass pipe <NUM> of the bypass <NUM> is connected to the second inlet end 62a, and the water return bypass pipe <NUM> of the bypass <NUM> is connected to the second outlet end 62b. Therefore, a total of four ports are provided on the heat exchanger <NUM>, the bypass <NUM> of the third fluid line enters the heat exchanger <NUM> and then flows through the second heat conduction channel. The second fluid line enters the heat exchanger <NUM> and then flows through the first heat conduction channel. Each heat conduction channel is formed by a sealing structure. The cooling medium in the second fluid line and the cooling medium in the third fluid line conduct heat transfer in the heat exchanger <NUM> in a co-current or cross-flow manner, so as to realize the mutual transfer and balance of the heat of the two cooling circuits. The four ports can be arranged on the same side of the heat exchanger <NUM>, or can be arranged on two sides of the heat exchanger <NUM>. <FIG> shows the specific structure of the second cooling circuit <NUM>. The second cooling circuit <NUM> is a converter cooling system, including the second fluid line, a plurality of second branch radiators <NUM> in parallel for cooling the second heating component <NUM>, a heater H, and various function valves and various sensors, to realize the normal, stable and maintainable operation of the second cooling circuit <NUM>.

Under the action of the pump station unit <NUM>, the cooling medium flows into the second water supply pipe <NUM> via the water distributor <NUM>, flows through the first heat conduction channel of the heat exchanger <NUM>, is then transported to the plurality of second branch heat exchangers <NUM> in parallel, and after conducting the heat exchange between respective branch heat exchangers with the second heating component <NUM>, converges to the second water return pipe <NUM>, then flows through the heat dissipation unit <NUM> and then flows back to the pump station unit <NUM> through the water collector <NUM> to realize a closed-circuit circulation.

Specifically, the second section <NUM> of the second water supply pipe <NUM> of the second cooling circuit <NUM> is provided with the plurality of second fluid branches <NUM> corresponding to the plurality of second heating components <NUM> one-to-one. The second branch radiator <NUM> is provided on each second fluid branch <NUM>. The second branch temperature sensor TT2 and the second branch flow sensor FF2 are arranged downstream of each second fluid branch <NUM>. Measured values of each second branch temperature sensor TT2 and each second branch flow sensor F22 are monitored, according to a target temperature value of each second heating component <NUM>, the opening of each second branch regulating valve VV2 is controlled to adjust the flow rate of the second fluid branch <NUM>.

In addition, according to different heat dissipation components and different heat dissipation forms, a second branch regulating valve VV2 is also provided downstream of each second fluid branch <NUM>. A faulty second branch regulating valve VV2 is intelligently closed according to the fault-tolerant operation of the second fluid branch <NUM>, to reduce a requirement of system flow resistance and realizes the energy saving of the pump station unit <NUM>.

Optionally, a heater H is provided on the first section <NUM> of the second water supply pipe <NUM>, and when the temperature of the cooling medium of the second cooling circuit <NUM> is lower than the preset temperature and the third heating component <NUM> is not activated, the heater H is activated.

Since the second heating component <NUM>, namely the converter, cannot be activated at extremely low temperature, it needs to be preheated by the cooling medium in the second cooling circuit <NUM>. If the third heating component <NUM>, i.e., the generator, is not activated, the converter can heat the cooling medium by starting the heater H, so as to meet the preheating requirement before the converter is activated. If the generator is activated during this period, the heater H is turned off and the bypass regulating valve 33a is opened. The waste heat generated by the generator can heat the cooling medium in the third cooling circuit <NUM> and enter the heat exchanger <NUM> through the bypass <NUM>. The cooling medium at a low temperature of the second cooling circuit <NUM> exchanges heat with the cooling medium at a high temperature in the third cooling circuit <NUM> in the heat exchanger <NUM> until a preset temperature is reached at which the converter can be activated. When the temperature of the cooling medium of the second cooling circuit <NUM> reaches the preset temperature, the converter starts to operate, and the bypass regulating valve 33a is closed. By reusing the waste heat of the generator and activating the heater H as little as possible, the self-consumption power of the system can be saved and the energy consumption of the system can be reduced.

Optionally, a second middle main temperature sensor T2 is further provided upstream of the second section <NUM>, and the opening/closing of the heater H and the opening of the bypass regulating valve 33a are controlled according to the measured value of the second middle main temperature sensor T2. By controlling the opening degree of the bypass regulating valve 33a, the flow rate of the cooling medium at a high temperature entering the bypass <NUM> is adjusted, thereby gradually heating the cooling medium in the second cooling circuit <NUM>.

In addition, according to the fault tolerance requirement of the second cooling circuit <NUM>, the plurality of second fluid branches <NUM> are arranged on the second section <NUM> of the second water supply pipe <NUM>. Second flexible pipes <NUM> are respectively arranged at the front and rear of the heat exchanger <NUM> to facilitate a line connection and vibration reduction.

Optionally, a second pressure monitoring device P2 downstream of the first section <NUM>, upstream of the second section <NUM>, and at least one of upstream and downstream of each second fluid branch <NUM>. Optionally, the second pressure monitoring device P2 includes a pressure transmitter and a pressure display device. The second pressure monitoring device P2 is used to locally and remotely monitor the resistance change and blockage replacement of the heat exchanger <NUM> on the second cooling circuit <NUM>. The second branch radiators <NUM> are respectively provided at the front and rear of each of the second pressure monitoring devices P2, to remotely and locally monitor a pressure change of the system.

Optionally, a second Valve V2 is provided on the second water supply pipe <NUM> and the second water return pipe <NUM>, downstream of the heater H, upstream of the second section <NUM>, and at least one of upstream and downstream of each second fluid branch <NUM>. Second valves V2 are respectively arranged on the second water supply pipe <NUM> and the second water return pipe <NUM>, so that the sensors and components of the second fluid line can be replaced and maintained. According to maintenance and replacement requirements, after any two second valves V2 are closed, corresponding operations can be performed on the internal sensors, pipe fittings and sensors.

Optionally, the first section <NUM> is provided with a second drain valve LV2, so as to effectively realize local liquid discharge and reduce an impact of component replacement on the entire system.

Optionally, the second water return pipe <NUM> is further provided with a second exhaust valve AV2, which can effectively realize an effective exhaust of the system and branch parts during a liquid injection process of the system.

<FIG> shows the specific structure of the third cooling circuit <NUM>. The third cooling circuit <NUM> is a generator cooling system, including a third fluid line, a plurality of third branch radiators <NUM> in parallel for cooling the third heating component <NUM>, and also various functional valves and various sensors, to realize the normal, stable and maintainable operation of the third cooling circuit <NUM>.

Under the action of the pump station unit <NUM>, the cooling medium flows into the third water supply pipe <NUM> via the water distributor <NUM>, is transported to the plurality of third branch heat exchangers <NUM> in parallel, after conducting the heat exchange between respective branch heat exchangers and the third heating component <NUM>, enters the third water return pipe <NUM>, and then flows through the heat dissipation unit <NUM> and then flows back to the pump station unit <NUM> via the water collector <NUM> to realize a closed-circuit circulation.

Specifically, the third fluid line is provided with a plurality of third fluid branches <NUM> corresponding to the third heating component <NUM> , the bypass <NUM> is arranged downstream of the plurality of third fluid branches <NUM>, and each third fluid branch 311A is provided with a third branch radiator <NUM>.

The third fluid line is also provided with a third temperature sensor T31 and a third flow sensor F31 located downstream of the third water supply pipe <NUM>, and a third bypass temperature sensor T32 and a third flow sensor F32 are provided on the bypass water return pipe <NUM> of the bypass <NUM>.

The cooling medium enters the third cooling circuit <NUM> along the third water supply pipe <NUM> via the water distributor <NUM> of the pump station unit <NUM>, and is divided into a plurality of third fluid branches <NUM> from the third water supply pipe <NUM> which enter respective third third branch radiators <NUM> uniformly. Each third branch radiator <NUM> may be a heat sink module or an air-water heat exchanger. When the bypass regulating valve 33a is opened, each cooling medium after heat exchange will converge to the third water return pipe <NUM> via the third fluid branch <NUM>, a part of the cooling medium will enter the second heat conduction channel of the heat exchanger <NUM> along the water supply bypass pipe <NUM> of the bypass <NUM>, after conducting the heat exchange with the second cooling circuit <NUM>, finally converges to the third water return pipe <NUM> with a main path of the third water return pipe <NUM>, and then flows through the heat dissipation unit <NUM> and then flows back to pump station unit <NUM> via the water collector <NUM>.

The opening of the bypass regulating valve 33a is controlled to adjust the flow rate of the cooling medium entering the heat exchanger <NUM>. According to a temperature difference between the third temperature sensor T31 and the third bypass temperature sensor T32 and the flow rate of the third bypass flow sensor F32, the waste heat transferred from the bypass <NUM> to the second cooling circuit <NUM> is obtained. Combined with the main temperature sensor TT and the third flow sensor F31 in the pump station unit <NUM>, through data statistics and analysis, the logical relationship between the heat dissipation of the third cooling circuit <NUM> and an environmental boundary, load of the set, system flow rate, etc. can be known.

Optionally, third pressure monitoring devices P3 are respectively provided upstream and downstream of the third water supply pipe <NUM>, at least one of the water supply bypass pipe <NUM> and the water return bypass pipe <NUM> of the bypass <NUM>. Optionally, each of the third pressure monitoring devices P3 includes a pressure transmitter and a pressure display device. Third pressure monitoring devices P3 are respectively provided upstream and downstream of the third water supply pipe <NUM>, which can remotely and locally monitor the pressure values before and after passing through the third branch radiator <NUM>.

Optionally, third valves V3 are provided upstream and downstream of the third water supply pipe <NUM> of the third fluid line, at least one of the water supply bypass pipe <NUM>, the water return bypass pipe <NUM> and a third water return pipe <NUM> of the bypass <NUM>. Optionally, third drain valves LV3 are provided upstream and downstream of the third water supply pipe <NUM> and at least one of respective third branch radiators <NUM>. Optionally, at least one of the third branch radiators <NUM> and the third water return pipe <NUM> is provided with a third exhaust valve AV3.

Third liquid drain valves LV3 are respectively provided upstream and downstream of the third water supply pipe <NUM> with, and the third cooling circuit <NUM> is drained by an opening and closing of the third valves V3. At the same time, a third exhaust valve AV3 is provided on the third water return pipe <NUM> to facilitate the effective exhaust of the system during liquid injection and operation.

The third branch radiators <NUM> are respectively provided with the third drain valves LV3 to achieve effective liquid discharge and exhaust of the third branch radiators <NUM>.

Optionally, two-way shut-off valves DV are respectively provided upstream and downstream of each third fluid branch <NUM>, so as to facilitate a disassembly and replacement of the third branch radiator <NUM> under a liquid condition. Meanwhile, third flexible pipes <NUM> are respectively provided on the third fluid branch <NUM> and the third water return pipe <NUM> to facilitate an installation of the third branch radiator <NUM>.

In addition, the heat exchanger <NUM> is also provided with the third pressure monitoring device P3 on the side where the third cooling circuit <NUM> is located. Third flexible pipes <NUM> are also provided at both ends of the line on this side. Third valves V3are provided at the front and rear of the heat exchanger <NUM> respectively, which can remotely and locally monitor the pressure values before and after the heat exchanger <NUM>. At the same time, the third bypass flow sensor F32 and the third bypass temperature sensor T32 are arranged on the water return bypass pipe <NUM>, and combined with the third temperature sensor T31, the heat exchange amount passing through the heat exchanger <NUM> can be known, so that the system can be managed in a refined manner to facilitate optimization and update of the system.

<FIG> shows the specific structure of the fourth cooling circuit <NUM>. The fourth cooling circuit <NUM> is a transformer cooling system, and includes a fourth fluid line, a fourth radiator <NUM> for cooling the fourth heating component <NUM>, and also various functional valves and various sensors to realize the normal, stable and maintainable operation of the fourth cooling circuit <NUM>.

Under the action of the pump station unit <NUM>, the cooling medium flows into the fourth water supply pipe <NUM> via the water distributor <NUM>, and is transported to the fourth heat exchanger <NUM>, after conducting the heat exchange between the fourth heat exchanger <NUM> and the fourth heating component <NUM>, enters the fourth water return pipe <NUM> and flows through the heat dissipation unit <NUM> and then flow back to the pump station unit <NUM> via the water collector <NUM> to realize a closed-circuit circulation. The fourth radiator <NUM> may be an air-water heat exchanger or an oil-water heat exchanger.

Specifically, the fourth fluid line is provided with a fourth radiator <NUM> , and the fourth water return pipe <NUM> is provided with a fourth regulating valve VV4 , a fourth temperature sensor TT4 and a fourth flow sensor FF4.

The measured values of the fourth temperature sensor TT4 and the fourth flow sensor FF4 are monitored, and the opening of the fourth regulating valve VV4 is controlled to adjust the flow rate of the fourth fluid line according to the target temperature value of the fourth heating component <NUM>. The fourth temperature sensor TT4 and the fourth flow sensor FF4 provided on the fourth water return pipe <NUM>, combined with the main temperature sensor TT in the pumping station unit <NUM> and by data statistics and analysis, is the same as that of the fourth cooling circuit <NUM> a logical relationship between the heat dissipation of the fourth cooling circuit <NUM> and an environmental boundary, load of the set, flow rate of the system, etc. can be known. Optionally, the fourth water supply pipe <NUM> and the fourth water return pipe <NUM> are respectively provided with fourth valves V4. Optionally, the fourth water supply pipe <NUM> and the fourth radiator <NUM> are respectively provided with a fourth drain valve LV4. Optionally, the fourth radiator <NUM> is further provided with a fourth exhaust valve AV4. Optionally, fourth pressure monitoring devices P4 are respectively provided on the fourth water supply pipe <NUM> and the fourth water return pipe <NUM>.

The fourth exhaust valve AV4 and the fourth drain valve LV4 provided on the fourth radiator <NUM> are convenient for exhausting and injecting-exhausting the fourth fluid line. The fourth flexible pipes <NUM> are respectively disposed at the front and rear of the fourth radiator <NUM> to facilitate the installation of the fourth radiator <NUM>. Similarly, the fourth pressure monitoring devices P4 are respectively provided at the front and rear of the fourth radiator <NUM>, so that the pressure of the fourth cooling circuit <NUM> can be effectively monitored locally and remotely. The fourth water supply pipe <NUM> is provided with a fourth drain valve LV4. By closing the fourth valves V4 on the fourth water supply pipe <NUM> and the fourth water return pipe <NUM>, the equipment, sensors, etc. on the fourth cooling circuit <NUM> can be replaced and maintained.

Please refer to <FIG> and <FIG> together. An embodiment of the present disclosure provides the heat dissipation unit <NUM>, which includes a plurality of heat dissipation branches 7a, and each heat dissipation branch 7a is provided with a fifth radiator 7b. The second water return pipe <NUM> of the second cooling circuit <NUM>, the third water return pipe <NUM> of the third cooling circuit <NUM>, and the fourth water return pipe <NUM> of the fourth cooling circuit <NUM> are respectively communicated with a fifth water supply pipe <NUM> of the heat dissipation unit <NUM>. The fifth water return pipe <NUM> of the heat dissipation unit <NUM> is communicated with the water collector <NUM>.

The second cooling circuit <NUM>, the third cooling circuit <NUM>, and the fourth cooling circuit <NUM> in the cooling system provided in the embodiment of the present disclosure converge to the heat dissipation unit <NUM>, and the heat dissipation unit <NUM> enters the pump station unit <NUM> in the form of a converging pipe. In order to reduce the number of pipes entering the heat dissipation unit <NUM> from the second cooling circuit <NUM>, the third cooling circuit <NUM> and the fourth cooling circuit <NUM>, when the overall loss of the system is moderate and the size of the pipes and processing meet process requirements, three pipes converge to the fifth water supply pipe <NUM>, and the cooling medium is cooled by each fifth radiator 7b. Similarly, the first cooling circuit <NUM> can also enter and exit the pump station unit <NUM> in a similar converging form as shown in <FIG>, thereby reducing the number of arrangements of the entire pipes on the wind power generator set.

Optionally, a fifth valve V5 is provided with the fifth water supply pipe <NUM> and the fifth water return pipe <NUM>, and at least one of upstream and downstream of each heat dissipation branch 7a. Optionally, the fifth water supply pipe <NUM> and at least one of the fifth radiators 7b are respectively provided with fifth drain valves LV5. Optionally, each fifth radiator 7b is further provided with a fifth exhaust valve AV5.

The fifth radiator 7b is provided with a fifth drain valve LV5 and a fifth exhaust valve AV5, and by closing the fifth valve V5 on the fifth water supply pipe <NUM> and the fifth return pipe <NUM>, the replacement of the fifth radiator 7b is realized, and at the same time, it is convenient for local drainage and cutting out with other components. By closing the fifth valves V5 on the fifth water supply pipe <NUM> and the fifth water return pipe <NUM>, the heat dissipation unit <NUM> can be drained through the fifth drain valve LV5. All heat dissipation branches 7a finally converge to the fifth water return pipe <NUM>, and enter the pump station unit <NUM> via the main water return pipe <NUM>, to form a closed-circuit circulation of the entire cooling system.

Referring to <FIG>, the embodiment of the present disclosure also provides another heat dissipation unit <NUM> similar to the heat dissipation unit <NUM> shown in <FIG>. The difference is that when the overall loss of the system is too high and the size and processing of the line cannot meet the requirements, the second cooling circuit <NUM>, the third cooling circuit <NUM>, and the fourth cooling circuit <NUM> enter the heat dissipation unit <NUM> as three-way lines. The three-way lines respectively enter the fifth radiator 7b through their respective fifth water supply branch pipes <NUM>, and into the pump station unit <NUM> through their respective fifth water return branch pipes <NUM>.

Specifically, the heat dissipation unit <NUM> includes the plurality of heat dissipation branches 7a, and the fifth radiator 7b is disposed between the fifth water supply branch pipe <NUM> and the fifth water return branch pipe <NUM> of each heat dissipation branch 7a.

The second water return pipe <NUM> of the second cooling circuit <NUM>, the third water return pipe <NUM> of the third cooling circuit <NUM>, and the fourth water return pipe <NUM> of the fourth cooling circuit <NUM> are respectively communicated to the fifth water supply branch pipe <NUM> of the heat dissipation branch 7a corresponding to them. The fifth water return branch pipes <NUM> of each heat dissipation branch 7a are communicated with the water collector <NUM> respectively.

Optionally, fifth valves V5 are provided respectively on each fifth water supply branch pipe <NUM> and each fifth water return branch pipe <NUM>, and at least one of an inlet and outlet of each fifth radiator 7b. Optionally, at least one of the fifth water supply branch pipe <NUM> and the fifth radiator 7b is provided with a fifth drain valve LV5. Optionally, each fifth radiator 7b is further provided with a fifth exhaust valve AV5, respectively. Through an opening and closing of the fifth drain valve LV5 provided on the fifth water supply branch pipe <NUM> and the fifth water return branch pipe <NUM> of each heat dissipation branch 7a, the liquid discharge of each heat dissipation branch 7a is effectively realized.

Referring to <FIG>, the embodiment of the present disclosure also provides a simplified schematic structural diagram of another cooling system of a wind power generator set, which is similar to the working principle of that of <FIG>, except that the cooling unit <NUM> shown in <FIG> and the first cooling circuit <NUM> shown in <FIG> are adopted. That is, each first fluid branch <NUM> and the heat dissipation unit <NUM> in the first cooling circuit <NUM> respectively enter the pump station unit <NUM> through lines independent of each other, the second cooling circuit <NUM>, the third cooling circuit <NUM> and the fourth cooling circuit <NUM> also enter the heat dissipation unit <NUM> through pipelines independent of each other. When the cooling capacity of the wind power generator set reaches a certain level, the cooling system shown in <FIG> can be used in order to facilitate the direction, layout and manufacturing process of the lines.

In the cooling system provided by an embodiment of the present disclosure, the first cooling circuit <NUM>, the second cooling circuit <NUM>, the third cooling circuit <NUM> and the fourth cooling circuit <NUM> corresponding to the heating components are integrated in a system in a form of independent lines respectively. After the loss of each heating component is exchanged with the cooling circuit, a direct circuit is set and a circulatory setting into the heat dissipation unit <NUM> is performed, which further simplifies a line configuration, reduces the number of heating components, and improves the utilization of the cooling capacity of the system.

The centralized cooling system provided by the embodiment of the present disclosure can effectively reduce the number of rotating components (such as pump sets) of the system, thereby improving the reliability of the system and reducing the failure rate. By optimizing the number of rotating components, the energy consumption of the cooling system during the operating time can be effectively reduced to improve the energy efficiency ratio of the entire cooling system. And by the fault-tolerant design of rotating components, while a reasonable distribution of cooling capacity is maintained, the fault tolerance and reliability of the entire cooling system are achieved.

The centralized cooling system provided by the embodiment of the present disclosure can effectively perform loss statistics and set the heat transfer direction during the operation of the set, and at the same time, combined with the ambient temperature, more reasonable components can be selected to provide sufficient statistical basis for subsequent evaluation.

The centralized cooling system provided by the embodiment of the present disclosure can dynamically adjust the cooling capacity configuration of a component with a small-capacity heating amount to reduce the complexity of line layout; and can fully utilize the waste heat resources of a heating component with a large-capacity heating amount to achieve a reasonable allocation of cooling and heating demand of the system.

In addition, the wind power generator set provided by the embodiment of the present disclosure adopts the aforementioned cooling system, which can effectively count the system loss and the heat transfer direction of the generator set during the operation, and combined with the ambient temperature to explore a more reasonable component selection, so as to provide sufficient statistical basis for subsequent evaluation of the reliability of wind power generator set.

In addition, the cooling system according to the above-described exemplary embodiment can be applied to various electrical equipments requiring a heat dissipation, such as but not limited to wind power generator set.

Claim 1:
A cooling system, comprising: a first cooling circuit (<NUM>) for cooling a first heating component (<NUM>), a second cooling circuit (<NUM>) for cooling a second heating component (<NUM>), a third cooling circuit (<NUM>) for cooling a third heating component (<NUM>), a fourth cooling circuit (<NUM>) for cooling a fourth heating component (<NUM>), a pump station unit (<NUM>) and a heat dissipation unit (<NUM>);
wherein the pump station unit (<NUM>) comprises a pump group (<NUM>), a water distributor (<NUM>) and a water collector (<NUM>), a main water supply pipe (<NUM>) is arranged between the pump group (<NUM>) and the water distributor (<NUM>), and a main water return pipe (<NUM>) is arranged between the pump group (<NUM>) and the water collector (<NUM>);
the pump group (<NUM>) provides a cooling medium for the first cooling circuit (<NUM>), the second cooling circuit (<NUM>), the third cooling circuit (<NUM>) and the fourth cooling circuit (<NUM>) via the water distributor (<NUM>);
the first cooling circuit (<NUM>) is directly communicated with the water distributor (<NUM>) and the water collector (<NUM>), and the second cooling circuit (<NUM>), the third cooling circuit (<NUM>), and the fourth cooling circuit (<NUM>) are respectively connected to the water collector (<NUM>) via the heat dissipation unit (<NUM>),
wherein the first heating component (<NUM>) has the smallest heat generation amount, the third heating component (<NUM>) has the largest heat generation amount, and each of the second heat generating component (<NUM>) and the fourth heat generating component (<NUM>) has a heat generation amount between the heat generation amount of the first heating component (<NUM>) and the heat generation amount of the third heating component (<NUM>).