TWI486269B - Thermal management device and method for electric vehicle vehicle system - Google Patents

Description

Electric vehicle complete vehicle system thermal management device and method

The invention relates to a thermal management device and a method for an electric vehicle complete vehicle system, in particular to a sub-system thermal management field of an electric vehicle, which performs respective management on the temperature of each subsystem of the vehicle, so that the subsystem temperature is maintained within a fixed range. To enable each subsystem to operate stably.

Since ancient times, human mobility tools have been transformed from bicycles, locomotives, automobiles, and electric vehicles. The invention of vehicles has shortened the distance from one place to another, making people everywhere no longer worried. Distance problems, and only a lifetime in the hometown, therefore, the population and culture are gradually diversified, people's horizons are gradually broad, and go out to various places, no longer need to spend months or even years.

With the development of transportation and the advancement of industrial and commercial technology, human civilization and technology have brought great convenience to life. The damage brought to the earth by relative convenience has also increased in proportion, and the annual emission increase and natural The consumption of resources, etc., has caused the stability of the earth to decline year by year. Therefore, local personnel and industry awareness of the green energy industry and the protection of the earth have gradually increased, and electric vehicles will also be born.

Vehicles that use electric motors as the driving power source are called "electric vehicles". Electric vehicles include various subsystems, such as batteries, battery control modules, motors, inverters, etc., while the subsystems of electric vehicles are in operation. The heat is generated and gradually accumulated. The rising temperature affects the operating efficiency of each subsystem, which in turn affects the operation and service life of the electric vehicle. Therefore, good vehicle system thermal management is an indispensable prerequisite. The thermal management of conventional vehicle systems usually involves connecting the thermal devices of each subsystem in a single or multiple cooling circuit, and dissipating heat by the heat sink and the fan. In the environment, the order of the subsystems passed by the cooling circuit is fixed, so the subsystem at the end of the loop will be affected by the heat of the front-end system, and the temperature of the single subsystem cannot be finely controlled. In addition, the temperature of the end subsystem is also Can not reduce, if you want to reduce the temperature of the end system of the loop, you need to strengthen the cooling capacity of the coolant, and the low-temperature coolant into the cooling circuit, which will lead to the reduction of electrical energy consumption and heat dissipation efficiency, so the above-mentioned shortcomings have yet to be overcome.

In view of this, the inventor of the present case has developed and designed related products based on years of research and development experience in the industry, and finally invented a "thermal management device and method for electric vehicle system" to address the temperature and efficiency of each subsystem. The degree of impact is different, and a set of methods for temperature management of individual subsystems is designed.

The main object of the present invention is to provide a "thermal management device and method for an entire vehicle system of an electric vehicle", which can improve the temperature control of a single subsystem without the conventional technology, thereby causing poor heat dissipation of each subsystem and affecting each subsystem. Lack of work efficiency, etc.

In order to achieve the above objects and effects, the apparatus and method for thermal vehicle system of the present invention include a coolant pump, a plurality of subsystems, a first heat dissipation pipeline, at least two multidirectional valves, and a control. The first heat dissipation pipeline includes a cooling pipeline and a recovery pipeline, and the coolant pump is connected to each subsystem by a cooling pipeline, and the coolant pump is connected to the subsystems for recycling. The pipelines are connected to form a circulation pipeline; the at least two multidirectional valves are respectively disposed on the cooling pipeline and the recovery pipeline, and the at least two multidirectional valves can open a passage of the coolant to the subsystems; the controller respectively The at least two multi-directional valves and the subsystems are electrically connected; In this way, the controller detects the temperature and temperature control state of each subsystem, and controls the opening sequence of the at least two multi-directional valves according to the temperature and temperature control state of each subsystem, so that the coolant flows to the subsystems in order to perform Cooling work.

The controller of the present invention includes a monitoring unit and a plurality of detecting units, wherein the monitoring unit is electrically connected to the detecting unit and the at least two multi-directional valves, and the plurality of detecting units are respectively connected to the plurality of subsystems. And detecting the temperature and heating and heat dissipation status of each subsystem, and returning the detection information to the monitoring unit, and sequentially operating the at least two multi-directional valves to circulate the coolant to the channels of the subsystems after the operation of the monitoring unit.

The invention further includes a plurality of flow control valves disposed in the cooling line and the recovery line, and the plurality of flow control valves are respectively located between the multi-directional valve and each subsystem to regulate the flow of the coolant to the subsystems. flow.

The invention further includes a plurality of heat exchangers disposed in the recovery line, and the heat exchanger is provided with a fan that delivers cold air from the external environment to the heat exchanger for heat exchange.

The invention further includes a second heat dissipation conduit having a water tank that communicates with the recovery conduit and the coolant pump.

The invention further includes an air conditioning system refrigerant line that communicates with the water tank to assist in reducing the temperature of the coolant or increasing the temperature of the coolant.

A method for operating a thermal management device for an electric vehicle system according to the foregoing, comprising the steps of: inputting a temperature range value: respectively inputting a temperature upper limit and a lower limit of a reference working interval of each subsystem, and starting conditions of each subsystem temperature control program The upper and lower limits are information on the controller; detecting the control information of each subsystem: the controller detects the operating temperature of each subsystem and the temperature control Program state; cooling flow direction sorting: the controller determines the priority of the temperature control demand of each subsystem according to the method of heat dissipation after heat dissipation, and according to the reference working temperature range of each subsystem and the starting condition of the temperature control program, thereby generating Flow sequence information; each subsystem thermal management program: input the operating temperature, temperature control status, and flow sequence information of each subsystem to the controller, so that the controller can judge each subsystem to perform heat dissipation, heating, or maintain the current program. By monitoring the control information of each subsystem at any time, and generating flow sequence information according to the needs of each subsystem, to execute the heat dissipation program, heating program or maintaining the current program, so that the temperature of each subsystem is maintained within the set range, thereby The system is stable.

The subsystem thermal management program of the present invention, the controller calculates the flow demand of each subsystem, and outputs flow adjustment information to the complex flow control valve, and the plurality of flow control valves adjust the flow of the coolant circulation of each subsystem according to the flow adjustment information. The port is sized to provide proper coolant flow to each subsystem.

The present invention is a cyclical step of detecting the regulatory information of each subsystem and performing the thermal management procedures of each subsystem.

In the thermal management program of each subsystem of the present invention, the sequence of execution of each subsystem is sequentially performed according to the flow sequence information in the sorting step of the coolant flow.

The above-mentioned subsystem thermal management mechanism can form a multi-moving, compound-type complete subsystem cooling circuit, which is adjusted with the temperature control requirements of each subsystem to achieve the effect of stabilizing the temperature of each subsystem.

The invention has the same utility in the "electric vehicle overall system thermal management device and method" Practicality and innovation are worthy of promotion by the industry and made public to the public.

The present invention relates to a "thermal management device for an electric vehicle system", as shown in the first to second figures, the device includes a coolant pump 1, a plurality of subsystems 2, a first a heat dissipation pipe 3, at least two multi-directional valves 4, 40, and a controller 5, wherein: the first heat dissipation pipe 3 includes a cooling pipe 30 and a recovery pipe 31 for cooling the coolant pump 1 The pipeline 30 is connected to the subsystems 2, and the coolant pump 1 is connected to the recovery pipeline 31 connected to each subsystem 2 to form a circulation pipeline. In this embodiment, the plurality of subsystems 2 includes a motor and an inverter. The at least two multi-directional valves 4, 40 are respectively disposed in the cooling line 30 and the recovery line 31, wherein a multi-directional valve 4 is disposed in the cooling line 30, Located between the coolant pump 1 and the plurality of subsystems 2, the multi-way valve 4 regulates the coolant pump 1 to the coolant ports of the subsystems 2 (the coolant here is the circulating coolant) Another multi-way valve 40 is disposed between the recovery line 31 and the subsystems 2, and the multi-way valve 40 is regulated and cooled. The port (the coolant here is the recirculating coolant), and the multi-way valves 4 and 40 located on the cooling line 30 or the recovery line 31 are respectively opened according to the temperature requirements of the respective subsystems 2, so that the coolant flows to the respective The subsystem 2 is configured to perform a cooling operation. The controller 5 includes a monitoring unit 50 and a plurality of detecting units 51. The monitoring unit 50 is electrically connected to the detecting unit 51 and the at least two multi-way valves 4 and 40, respectively. The complex detection unit 51 is electrically connected to the plurality of subsystems 2, and the detection unit 51 detects the temperature of each subsystem 2 and the heat dissipation and heating states, and returns the detection information to the monitoring unit 50 to make the monitoring unit 50 operation back detection information to control the at least two multi-way valves 4, 40 to open the coolant flow to each subsystem 2 The sequence is sequential and the cooling is performed for the needs of each subsystem 2.

The cooling line 30 and the recovery line 31 are provided with a plurality of flow control valves 6, 60. The flow control valves 6, 60 are disposed between the at least two multi-directional valves 4, 40 and the subsystems 2, and the flow control The valves 6, 60 are capable of controlling the size of the port of the cooling pipe 30 to moderately adjust the flow rate of the coolant flowing into each of the subsystems 2; the recovery line 31 is provided with a heat exchanger 7 and corresponding to the heat exchanger 7 A fan 70 is provided, the heat recovered by the coolant from each subsystem 2, and the fan 70 transmits cold air from the external environment to the heat exchanger 7 for heat exchange, thereby reducing the temperature of the coolant; the recovery pipeline 31 is A second heat dissipating pipe 9 having a water tank 8 is connected, and the water tank 8 is connected to an air conditioning system refrigerant pipe 80. When the coolant is heated due to ambient temperature or heat generated by the system, the coolant cannot be smoothly lowered below a preset value. When the air conditioning system refrigerant line 80 can assist the heat dissipation of the cooling liquid, the low temperature refrigerant is used to reduce the temperature in the cooling liquid to below the preset temperature of the plurality of subsystems 2; on the other hand, when the temperature of each subsystem 2 Insufficient, the air conditioning system refrigerant The road 80 can provide cooling liquid heating, and raise the temperature of the subsystem 2 with insufficient temperature to a preset temperature range; further describe the operation method according to the above description of the thermal management device of the vehicle complete vehicle system, wherein the operating steps include input temperature Range value, detection of subsystem control information, coolant flow sequencing, thermal management procedures for each subsystem, the steps are as follows, please refer to the third figure: input temperature range value: input the reference working interval of each subsystem 2 The upper and lower temperature limits and the temperature control program start condition are in the controller, which includes the following sub-steps, as shown in the fourth to sixth figures: (a) selecting the subsystem 2 to be temperature-controlled, as shown in the second figure. The selected motor, inverter, battery, and DC converter are each required to perform temperature control of the subsystem 2; (b) input the upper and lower temperature limits of the reference working interval, according to the efficiency-temperature graph of each subsystem 2, such as As shown in FIG. fifth, the operation corresponding to the highest efficiency (Ei _H) and the lowest operation efficiency (Ei _L) are input to fetch the highest efficiency of the controller 5 in FIG temperature (Ti _H) and the minimum temperature efficiency (Ti _L) At maximum efficiency and temperature (Ti _H) and the minimum temperature efficiency (Ti _L) of the upper temperature limit of the reference data to the controller of the working region 5 (the present embodiment is a T _H) and the lower temperature limit of the reference interval work (in this embodiment T _L ), as shown in the sixth figure; (c) setting the upper limit of the temperature control program starting condition of each subsystem 2 (this embodiment is a set temperature T ₂ ) and the lower limit (this embodiment is a set temperature T ₁ ) The temperature control program starting condition upper limit (T ₂ ) and the lower limit (T ₁ ) are input to the controller 5, and the upper temperature limit (T _H ) of the reference working interval and the lower temperature limit of the reference working interval are determined according to the step (b) ( T _L ) generates a hysteresis curve condition map, as shown in the sixth figure, when the temperature of each subsystem 2 rises above the upper limit of the temperature control program start condition (T ₂ ), the heat dissipation process is performed, if the temperature of each subsystem 2 is lower than the temperature control The heating program is executed at the lower limit of the program start condition (T ₁ ). The set values entered above in the controller 5 are used as a database for overall thermal management.

Detecting the control information of each subsystem: the controller 5 detects the operating temperature and the temperature control state of each subsystem 2, and the temperature control state is currently the heating state or the heat dissipation state of each subsystem 2; the flow direction of the cooling liquid is sorted: the controller 5 follows Firstly, the method of heating after heat dissipation, and determining the priority of the temperature control demand of each subsystem 2 according to the reference working temperature range of each subsystem 2 and the starting condition of the temperature control program, thereby generating flow order information; Each subsystem thermal management program: input the operating temperature, temperature control state, and flow sequence information of each subsystem 2 to the controller 5, respectively, so that the controller 5 can judge that each subsystem 2 needs to perform a heat dissipation process, a heating process, or maintain the current program. .

The following is a detailed description of the steps of the subsystem thermal management program, as shown in the seventh figure, which is mainly based on the operating temperature and hysteresis curve of the current subsystem 2 (as shown in the sixth figure). T ₂ ) and the lower limit of the temperature control program start condition (T ₁ ) are compared to determine the number of temperature control mechanisms that the subsystem 2 needs to perform, such as the heat dissipation process, the heating process, or the maintenance of the current program. If the temperature of the subsystem 2 is higher than the upper limit of the temperature control program starting condition (T ₂ ), the heat dissipation program is entered; if the temperature of the subsystem 2 is lower than the upper limit of the temperature control program starting condition (T ₂ ), whether the temperature of the subsystem 2 is lower than the temperature control The lower limit of the program start condition (T ₁ ) is determined. If the temperature of the subsystem 2 is lower than the lower limit of the temperature control program start condition (T ₁ ), the heating program is entered; if the temperature of the subsystem 2 is higher than the lower limit of the temperature control program start condition (T ₁ ), Then, the current temperature control program is maintained; therefore, the controller 5 reads the temperature control mechanism program required for each subsystem 2 and executes the programs in sequence.

Referring to the eighth figure, which is the heat dissipation program in the subsystem management program step, according to the subsystem 2 operating temperature parameter pre-inputted into the controller 5, the controller 5 can calculate that the current subsystem 2 is lowered from the operating temperature. The temperature control program starts the heat dissipation amount required for the lower limit of the condition (T ₁ ), and then the controller 5 determines whether the temperature of the recirculating coolant is lower than the lower limit of the temperature control program start condition (T ₁ ) (recycle liquid is the previous subsystem) 2 The coolant flowing out) If the temperature of the recirculating coolant is lower than the lower limit of the temperature control program start condition (T ₁ ), the following steps are performed in sequence:

(i) Recirculating Coolant Flow Calculation: Calculate the flow rate of the recirculating coolant required for each subsystem 2 based on the amount of heat dissipated required by the aforementioned subsystem 2.

(ii) Closing the multi-way valve of the circulating coolant: closing the multi-directional direction of the cooling line 30 The valve 4 prevents the circulating coolant (i.e., the coolant sent from the coolant pump 1 at the front end of each subsystem 2) from flowing to the respective subsystems 2.

(iii) Recirculating coolant flow control valve opening degree adjustment: according to the flow demand of each subsystem 2, and controlling the flow control valve 6 of each subsystem 2, to regulate the flow rate of the recirculating coolant of the subsystem 2, and complete the heat dissipation program.

If the temperature of the recirculating coolant is higher than the upper limit of the temperature control program starting condition (T ₁ ), then the determination is made whether the temperature of the subsystem 2 is lower than the temperature of the recirculating coolant, and if the temperature of the subsystem 2 is lower than the temperature of the recirculating coolant, then The foregoing recirculating coolant flow calculation step; if the temperature of the subsystem 2 is higher than the recirculating coolant temperature, it indicates that the recirculating coolant is not suitable for adjusting the temperature of each subsystem 2, and the controller 5 performs the following steps in sequence. :

(i) Circulating Coolant Flow Calculation: The flow rate of the circulating coolant required for each subsystem 2 is calculated based on the amount of heat dissipation required by the aforementioned subsystem 2.

(ii) Closing the multi-way valve of the recirculating coolant: closing the multi-way valve 40 port located in the recovery line 31, so that the recirculating coolant cannot flow into each of the subsystems 2 for cooling.

(iii) Circulating coolant flow control valve opening degree adjustment: according to the flow demand of each subsystem 2, and controlling the flow control valve 60 of each subsystem 2, to regulate the flow rate of the circulating coolant of the subsystem 2, and complete the heat dissipation process.

Referring to the ninth figure, which is the heating program in the subsystem management program step, according to the subsystem 2 operating temperature parameter pre-inputted into the controller 5, the controller 5 calculates that the current subsystem 2 has risen from the operating temperature to the temperature. The amount of heating required to control the upper limit of the program start condition (T ₂ ), and then the controller 5 determines whether the temperature of the recirculating coolant is higher than the upper limit of the temperature control program start condition (T ₂ ), if the temperature of the recirculating coolant is higher than the temperature The upper limit of the control program start condition (T ₂ ) is used to calculate the recirculating coolant flow rate, and the flow rate of the recirculating coolant required for each subsystem 2 is calculated according to the heating amount required by the subsystem 2, and the steps and heat dissipation procedures are performed. The same, that is, the multi-way valve 4 that closes the circulating coolant and the opening degree adjustment of the recirculating coolant flow control valve 6; if the recirculating coolant temperature is lower than the upper limit of the temperature control program starting condition (T ₂ ), the temperature of the subsystem 2 is performed. Whether it is higher than the judgment of the temperature of the recirculating coolant, if the temperature of the subsystem 2 is higher than the temperature of the recirculating coolant, the step of calculating the recirculation coolant flow described above is entered; if the temperature of the subsystem 2 is lower than Circulating the coolant temperature, the coolant flow is circulated sequentially calculating, the step of closing the recirculation control valve 60 as much as the degree of opening adjustment valve 40 and a circulation coolant flow, the heat dissipation system and the procedures of each step of the same.

Therefore, each step is sequentially performed to obtain the heat dissipation program, the heating program, or the current program control information of each subsystem 2, so that the two multi-way valves 4, 40 turn on or off the coolant to the subsystems according to the regulation information. The channel further provides that the temperature of each subsystem 2 is maintained within a set range, so that each subsystem 2 can operate stably.

In the foregoing subsystem thermal management program, the controller 5 calculates the flow demand of each subsystem 2, and outputs flow adjustment information to the complex flow control valves 6, 60. The complex flow control valves 6, 60 adjust the information according to the flow rate. The size of the port of the coolant flowing through each subsystem 2 is adjusted to provide an appropriate flow of coolant to each subsystem 2.

The steps described above for detecting the control information of each subsystem and even the thermal management procedures of each subsystem are cyclic steps to continuously cycle the steps so that each subsystem 2 can be maintained within the normal operating temperature range.

In the foregoing subsystem thermal management program, the order in which each subsystem 2 executes is sequentially performed in accordance with the flow sequence information in the sorting step of the coolant flow.

The above description is only for explaining the preferred embodiment of the present invention, and is not intended to be based on the present invention. It is to be understood that any modification or alteration of the present invention in the spirit of the same invention should be included in the scope of the present invention.

In summary, the "electric vehicle overall system thermal management device and method" of the present invention is completely in line with the needs of industrial development in terms of structural design, practicality and cost-effectiveness, and the disclosed structural invention also has Unprecedented innovative structure, so its "novelty" should be undoubted, and the invention can be more effective than the conventional structure, so it is also "progressive", which fully complies with the application for invention patents in China's patent law. The requirements of the requirements are to file a patent application in accordance with the law, and I would like to ask the bureau to review it as soon as possible and give it affirmation.

1‧‧‧Cooling pump

2‧‧‧ subsystem

3‧‧‧First heat pipe

30‧‧‧Cooling line

31‧‧‧Recycling pipeline

4‧‧‧Multidirectional valve

40‧‧‧Multidirectional valve

5‧‧‧ Controller

50‧‧‧Monitoring unit

51‧‧‧Detection unit

6‧‧‧Flow control valve

60‧‧‧Flow control valve

7‧‧‧ heat exchanger

70‧‧‧fan

8‧‧‧Water tank

80‧‧‧Air conditioning system refrigerant pipeline

9‧‧‧Second heat pipe

The first figure is a block diagram of the apparatus of the present invention.

The second figure is a schematic diagram of the configuration of the device of the present invention.

The third figure is a flow chart of the steps of the temperature control program of the present invention.

The fourth figure is a flow chart of the steps of the input temperature range value of the present invention.

The fifth graph is a graph of the efficiency-temperature curve of the present invention.

The sixth figure is a heat dissipation demand diagram of the present invention.

The seventh diagram is a flow chart of the subsystem thermal management program of the present invention.

The eighth figure is a heat dissipation flowchart of the present invention.

The ninth drawing is a heating flow chart of the present invention.

1‧‧‧Cooling pump

2‧‧‧ subsystem

3‧‧‧First heat pipe

30‧‧‧Cooling line

31‧‧‧Recycling pipeline

4‧‧‧Multidirectional valve

40‧‧‧Multidirectional valve

5‧‧‧ Controller

50‧‧‧Monitoring unit

51‧‧‧Detection unit

Claims (9)

An electric vehicle overall system thermal management device includes a coolant pump, a plurality of subsystems, a first heat dissipation pipeline, at least two multidirectional valves, and a controller, wherein: the first heat dissipation pipeline includes a a cooling pipe and a recovery pipe, the coolant pump is connected to each subsystem by a cooling pipe, and the coolant pump is further connected with the recovery pipeline connecting the subsystems to form a circulation pipeline; the at least two directions The valves are respectively disposed in the cooling pipeline and the recovery pipeline; the controller is electrically connected to the at least two multi-directional valves and the subsystems respectively; the controller includes a monitoring unit and a plurality of detecting units, and the monitoring The unit is electrically connected to the detecting unit and the at least two multi-directional valves, and the plurality of detecting units are respectively connected to the plurality of subsystems, and detecting temperature, heating and heat dissipation status of each subsystem, and returning detection The monitoring information is sent to the monitoring unit, and after the monitoring unit calculates, at least two multi-directional valves are sequentially flowed to the channels of the subsystems; thus, the controller detects the temperature and temperature control state of each subsystem, and according to each sub-sub system Temperature control and temperature state of the at least two multidirectional opening sequence of the valve, so that coolant flows sequentially for cooling the various subsystems work. The electric vehicle overall system thermal management device according to claim 1, further comprising a plurality of flow control valves disposed in the cooling pipe and the recovery pipe, wherein the plurality of flow control valves are respectively located at the second Multi-directional valve and each subsystem. The electric vehicle overall system thermal management device according to claim 1, further comprising a heat exchanger disposed in the recovery pipeline, and a heat exchanger corresponding to the heat exchanger, the fan transmitting the external environment The cold air is sent to the heat exchanger for heat exchange. The electric vehicle overall system thermal management device according to any one of claims 1 to 3, further comprising a second heat dissipating pipe having a water tank, wherein the second heat dissipating pipe is connected to the recovery pipe And the coolant pump. The electric vehicle overall system thermal management device according to claim 4, further comprising an air conditioning system refrigerant line connected to the water tank to reduce the temperature of the cooling liquid or increase the temperature of the cooling liquid. An operating method of a thermal management device for an electric vehicle system according to claim 1 of the patent application, comprising the steps of: inputting a temperature range value: respectively inputting a temperature upper limit and a lower limit of a reference working interval of each subsystem, and The temperature upper and lower limits of each subsystem temperature control program start condition are information on the controller; detecting the control information of each subsystem: the controller detects the working temperature of each subsystem and the temperature control program state; the coolant flow direction is sorted: the controller according to the first The method of heating after heat dissipation, and according to the reference working temperature range of each subsystem and the starting condition of the temperature control program, the priority of the temperature control demand of each subsystem is determined, and then the flow sequence information is generated; the thermal management procedures of each subsystem: respectively Input the operating temperature, temperature control status, and flow sequence information of each subsystem to the controller, so that the controller can judge each subsystem to perform heat dissipation, heating, or maintain the current program; by monitoring the control information of each subsystem at any time, And generate flow sequence information according to the requirements of each subsystem to execute the heat dissipation process and the heating process Preface or maintain the current procedure, so that the temperature of each subsystem is maintained within the set range, so that each subsystem can operate stably. According to the sixth aspect of the patent application scope, the thermal management device for the entire vehicle system of the electric vehicle The operating method, wherein each subsystem thermal management program, the controller calculates the flow demand of each subsystem, and outputs flow adjustment information to the plurality of flow control valves, the plurality of flow control valves adjust the cooling liquid of each subsystem according to the flow adjustment information The flow port is sized to provide proper coolant flow to each subsystem. The method for operating a thermal management device for an electric vehicle system according to claim 6 is characterized in that the step of detecting the information of each subsystem and the thermal management program of each subsystem is a cyclic step. The method for operating a thermal management device for an electric vehicle system according to claim 6, wherein each subsystem thermal management program, the sequence of execution of each subsystem is based on flow direction information in the flow direction of the cooling liquid. Execute separately.