JP7341726B2 - fuel cell device - Google Patents

Description

The present disclosure relates to a fuel cell device.

In a fuel cell device, water is involved in many processes, and a large amount of water used in these processes is stored in a water tank. Therefore, when the fuel cell device is operated or stopped for a long period of time, the inside of the water tank and the piping through which the water circulates are "drained."

Then, before restarting the operation of the fuel cell device, "water filling" is performed to fill the water tank and pipes with water.

The fuel cell power generation system described in Patent Document 1 has a "water filling mode" that automatically fills the tank with water, so that a user or the like can easily fill the tank with water.

For example, the aforementioned fuel cell power generation system is set to start water filling mode when the water filling operation section is operated, and there is a display on the operation panel, such as a water filling switch, asking whether water filling mode is necessary. On the other hand, when information indicating that the mode is necessary is input, such as by pressing a display button, the above-mentioned water filling mode is started.

Japanese Patent Application Publication No. 2011-34075

However, the system described in Cited Document 1 does not take into account "freezing of water pipes" that occurs in winter or in cold regions. Therefore, there was no way to check whether or not water filling was automatically and normally continued during periods when there was a possibility of freezing. As a result, when water filling was performed at low temperatures, freezing occurred inside the piping, etc., and water filling could not be completed.

An object of the present disclosure is to provide a fuel cell device that can suppress the occurrence of freezing and safely fill with water.

The fuel cell device of the present disclosure includes a casing, a fuel cell disposed within the casing, a water supply channel connected to a water supply source, a water tank that stores water necessary for operating the fuel cell, and an external water tank. a first temperature measuring section that measures the air temperature; a second temperature measuring section that measures the temperature inside the housing; and a third temperature measuring section that measures the temperature of at least one of the water tank and the water supply flow path. , a control device.
The control device sets a predetermined first temperature set in relation to the outside air temperature measured by the first temperature measuring section as a first water supply condition, and the second temperature measuring section and the third temperature measuring section The set temperature set in relation to each measured temperature is set as the second water supply condition.
When the first water supply condition is determined and the first water supply condition is not satisfied, water supply to the water tank is waited for , and then, when there is a request for confirmation of the second water supply condition, the first water supply condition is determined. As determination control, determination of the second water supply condition is performed.

According to the fuel cell device of the present disclosure, the occurrence of freezing is suppressed, and water filling can be performed safely and reliably.

1 is a schematic configuration diagram of a fuel cell device according to an embodiment. FIG. 2 is a perspective view showing the configuration of the fuel cell device inside the outer case. It is a flowchart regarding first determination control. It is a flowchart regarding second determination control.

Hereinafter, embodiments will be described with reference to the drawings.

FIG. 1 is a block diagram schematically showing the configuration of a fuel cell device according to an embodiment. Note that some of the general-purpose devices and equipment in the fuel cell device are not explained in detail, but are only given symbols in the drawings.

A fuel cell device 100 shown in FIG. 1 includes a fuel cell module 1 housed in a storage container 10, a heat exchanger 2 connected to the fuel cell module 1, and high temperature exhaust gas discharged from the fuel cell module 1. The heat storage tank 3 recovers heat and thermal energy through heat exchange and stores it as hot water. A reformed water tank 6 is provided to store reformed water (hereinafter referred to as "reformed water").

Note that the heat storage tank 3 and the reformed water tank 6 described above are both examples of a water tank that stores water necessary for operation of the fuel cell according to the present disclosure. In this embodiment, the temperature and freezing prevention around the heat storage tank 3, which has a relatively large amount of water stored therein, will be mainly explained.

The fuel cell device 100 includes a raw fuel supply device including a raw fuel pump B1, a raw fuel channel, etc., and an oxygen-containing gas supply device including an air blower B2, an oxygen-containing gas channel, etc. It also includes a reformed water supply device including a condensed water flow path C, the above-mentioned reformed water tank 6, a reformed water supply pump P1, and a reformed water flow path R for continuing water self-sustaining operation.

Furthermore, a heat medium circulation system (first heat cycle) consisting of the heat exchanger 2, heat storage tank 3, radiator 4, heat medium circulation pump P2, and the heat medium circulation channel HC1 that connects these in an annular manner. Equipped with

The fuel cell device 100 also includes a second heat exchanger 5 for heating tap water (tap water) to be supplied to the outside, and a second heat exchanger 5 for taking out and circulating a high temperature heat medium from the aforementioned heat storage tank 3. The hot water supply system (second heat cycle) includes a heating pump P3, a heat medium circulation channel HC2, and the like. Note that the fuel cell device may be a so-called monogeneration system that does not supply hot water to the outside.

The fuel cell device 100 then supplies (referred to as water supply) or replenishes (referred to as supplementary water) external water such as tap water, which is a water supply source, to the heat storage tank 3 and reformed water tank 6, which are the water tanks described above. It is equipped with water supply channels (piping) K1 and K2 for the purpose of water supply.

The water supply channels (pipes) K1 and K2 are equipped with water supply valves V ₁ and V ₂ including electromagnetic on-off valves and the like for starting and stopping water supply. The fuel cell device 100 shown in FIG. 1 also includes a water supply channel (piping) Win that supplies tap water, which is a water supply source, to the second heat exchanger 5.

The water supply channels (piping) K1, K2, and Win are examples of the water supply channels of the present disclosure. The fuel cell device 100 may have one water supply source and K1, K2, and Win as branch pipes.

Note that the fuel cell device 100 is disposed in a case 70 that includes frames 71 and exterior panels 72, as shown in FIG. Inside the case 70, the following control means, multiple measuring instruments and sensors, and other auxiliary equipment are installed around the fuel cell module 1 and each auxiliary equipment, flow paths, piping, etc. It is being

The fuel cell device 100 also includes a power generation amount adjusting device (power conditioner 20) as a means for controlling the operation of the aforementioned fuel cell module 1 and each auxiliary device, and a fuel cell A control device 30 that controls the operation of each auxiliary device that assists in the power generation operation of the system, and an operation board (operation panel) 40 installed indoors for a user etc. to issue instructions to the control device 30 are provided. .

The control device 30 is connected to a storage device, a display device (both not shown), various components and various sensors that constitute the fuel cell device 100, and controls the entire fuel cell device 100, including each of these functional parts. Control and manage. The control device 30 obtains a program stored in a storage device (not shown) attached to the control device 30 and executes this program to realize various functions related to each part of the fuel cell device 100.

The control device 30 also includes a ventilation fan 50 for discharging heat generated within the case 70 to the outside of the case, and a plurality of anti-freezing devices installed around the aforementioned heat medium circulation system (flow path) HC1 and HC2. and a heater 60 (only a part of which is shown).

Further, the fuel cell device 100 includes a plurality of temperature measuring instruments or thermometers such as temperature sensors and thermistors (hereinafter abbreviated as TM) for measuring the temperature of each part inside and outside the housing (case 70).

For example, as shown in FIG. 1, a thermistor TM1 is provided as a first temperature measurement section for measuring the environmental temperature (hereinafter referred to as outside temperature) outside the housing (case 70). Further, a thermistor TM2 for measuring the temperature (air temperature) inside the housing is arranged as a second temperature measuring section.

Furthermore, as a temperature measuring device or thermometer for measuring the temperature of water related to water filling and freezing of water, the thermistor TM3 is used to measure the temperature of the lower part of the heat storage tank 3, which corresponds to the low temperature part of the water that is the heat medium. installed. Further, in order to measure the temperature of tap water flowing into the case 70, a thermistor TM4 is attached to the water supply channel K1.

Note that there are no restrictions on the placement position of the thermistor TM4 as long as it can directly or indirectly measure the temperature of the tap water flowing into the case 70 (particularly the tap water supplied to the heat storage tank 3). do not have. For example, when each water supply channel branches from one water supply source, it may be provided in any of the branch channels. These thermistors TM3 and TM4 are an example of a third temperature measuring section of the present disclosure.

In addition, a thermistor TM5 is provided as a temperature measuring section to measure the temperature at a location where freezing is likely to occur, for example, the downstream position of the radiator 4 in the first heat cycle (circulation flow path) HC1. has been done.

When transmitting control signals or various information from the control device 30 to other functional units or devices, the control device 30 and the other functional units may be connected by wire or wirelessly. The control characteristic of this embodiment performed by the control device 30 will be described later.

In the embodiment, the control device 30 particularly controls the supply of external water (the above-mentioned "water filling" operation). Further, in each figure, illustration of connection lines connecting the control device 30 and each device and each sensor that constitute the fuel cell may be omitted.

In the fuel cell device 100 having the above configuration, for example, due to a long-term suspension of operation or suspension of operation, the water tank and the piping through which the water circulates have already been drained, and in order to resume operation, Control when "filling" a water tank or the like with tap water is performed as follows.

The control of the fuel cell device described below takes into consideration the "freezing of water pipes" that occurs in winter or in cold regions, and aims to complete the water filling operation at low temperatures. This control may be applied to all products shipped to various regions, regardless of the possibility of freezing, or may be applied to special product specifications applicable to cold regions, or to one selectable item for all products. It may also be installed as a mode in the section. Further, similar control can also be applied to a water filling operation performed by an administrator or the like before the first operation after installation of the fuel cell device, such as a trial run.

3 and 4 are charts showing a control flow for "filling with water" of the fuel cell device 100. FIG. 3 shows the flow of the first determination control by the control device, and FIG. 4 shows the flow of the second determination control that follows. In each flowchart, "satisfied (affirmative)" in the determination control is represented by [Yes], and "not satisfied (negative)" is represented by [No].

“Water filling” of the fuel cell device 100 of the embodiment shown in FIG. 3 can be performed, for example, by a user operating the remote control operation panel of the fuel cell device, or by a maintenance manager or the like operating the maintenance panel of the fuel cell device. It starts with an "instruction" to start, such as by operating a switch. Here, the start instruction may be an instruction to perform only water filling, or may be an instruction including water filling in a series of operations, such as an instruction to start up the fuel cell device 100.

Note that, hereinafter, "Step 1" and the like in the figures will be abbreviated as [S1] and the like. Further, the control device 30 stores the above-mentioned "instruction" to start by the user or the like, and uses this as the basis for executing the following series of controls. That is, this start instruction also serves as an execution instruction or determination request for the "second water supply condition confirmation request" or "first determination control" described later.

When the control starts, the control device 30 first sets the outside temperature It is determined whether the temperature is higher than a first temperature (hereinafter, first predetermined temperature X1 (° C.)).

In the embodiment, this first predetermined temperature X1 is appropriately set, for example, within a range of 5 to 10°C. Then, in [S1], if the outside temperature Start [S10].

On the other hand, in [S1], if the outside temperature X measured by thermistor TM1 is [No] below the first predetermined temperature X1, the following first temperature control [S2] and subsequent first determination control [S3] are performed. ～Start [S5].

That is, the control device 30 determines the second water supply condition as the first determination control. Here, the second water supply condition can be configured by temperatures at a plurality of locations, such as the temperature inside the housing, the temperature inside the water tank, and the temperature inside the water piping.

In addition, in performing the first determination control, the control device 30 stops the operation of the heating device (anti-freezing heater 60) and the flow device (ventilation) as the first temperature control before confirming each of these temperatures. Start driving the fan 50) [S2].

As mentioned above, the stoppage of the antifreeze heater 60 and the drive of the ventilation fan 50 continue to be maintained until an instruction to end the first temperature control is given in [S6]. . This is to bring the internal temperature of the casing (case 70) closer to the environmental temperature (outside temperature) outside the casing, and to accurately determine whether there is a possibility of freezing based on the current situation around the device. be.

After starting the first temperature control in [S2], next, the first judgment control is performed to sequentially judge the three second water supply conditions of [S4-1], [S4-2], and [S4-3]. Execute [S3].

Specifically, as the first (1/3) second water supply condition, the temperature (air temperature) Y (℃) inside the case 70 measured by the thermistor TM2, which is the second temperature measuring section, is determined in advance. It is determined whether or not the second temperature (hereinafter referred to as second predetermined temperature Y1 (° C.)) is higher than the second temperature Y1 (° C.).

In the embodiment, the second predetermined temperature Y1 is appropriately set at a relatively lower temperature than the first predetermined temperature X1, for example within a range of 1 to 5°C. Then, in [S4-1], if the temperature Y inside the case 70 is [Yes] equal to or higher than the second predetermined temperature Y1, the control device 30 determines that there is no risk of freezing regarding the temperature inside the case, and Proceed to the second (2/3) determination of the second water supply condition.

In addition, in [S4-1], if the temperature Y is less than the second predetermined temperature Y1 (No), the "second determination control" described in FIG. move on. The second determination control will be explained later.

In the second (2/3) second water supply condition [S4-2], the temperature W inside the heat storage tank 3 (°C, in this case, the air temperature ) is equal to or higher than a predetermined third temperature (hereinafter referred to as third predetermined temperature W1 (° C.)).

In the embodiment, the third predetermined temperature W1 is appropriately set at a relatively lower temperature than the first predetermined temperature X1, for example within a range of 1 to 5°C. Note that it may be the same as the second predetermined temperature Y1. Then, in [S4-2], if the temperature W inside the heat storage tank 3 is [Yes] equal to or higher than the third predetermined temperature W1, the control device 30 determines that there is no risk of freezing even if water is supplied to the water tank. Then, the process proceeds to the third (3/3) determination of the second water supply condition.

On the other hand, in [S4-2], if the temperature W is less than the third predetermined temperature W1 (No), as in [S4-1], the process described in FIG. Proceed to "second judgment control".

Next, in the third (3/3) second water supply condition [S4-3], the temperature Z (℃, this In this case, it is determined whether or not the tube temperature) is equal to or higher than a predetermined fourth temperature (hereinafter referred to as fourth predetermined temperature Z1 (° C.)).

In the embodiment, the fourth predetermined temperature Z1 is appropriately set at a relatively lower temperature than the first predetermined temperature X1, for example, within a range of 1 to 5°C. Note that the temperature may be the same as the second and third predetermined temperatures, or may be a lower temperature. Then, in [S4-3], if the temperature Z of the water supply flow path K1 is [Yes] equal to or higher than the fourth predetermined temperature Z1, the control device 30 determines that there is a risk of freezing even if water is passed through each flow path piping. It is determined that there is no one, and the process proceeds to the next standby step [S5].

In addition, in [S4-3], if the temperature Z is less than the fourth predetermined temperature Z1 (No), as in [S4-2], the flowchart is indicated by the arrow (A) as shown in FIG. Proceed to "second judgment control".

With the above configuration, the possibility of freezing occurring within the housing (case 70) can be further reduced.

In addition, in the above-mentioned second water supply condition, only one location on the water supply channels K1, K2, and Win is illustrated as the location where the temperature of the piping is measured, but the location where the piping temperature is measured is other locations on the circulation piping. It is also possible to increase the number of measurements (frequency) by replacing the thermometer with a different location or by installing thermometers in more locations.

For example, in the second water supply condition [S4-3], a thermistor may be provided in the water supply channel K2, and the temperature of the water supply channel K2 may be set as a condition. In this case, the temperature measured by the thermistor of the K2 pipe may be added as the fourth condition (step) of the second water supply condition. Furthermore, when the water supply source is one and K1, K2, and Win are branched pipes, a thermistor may be disposed in the pipe common to the water supply channels K1, K2, and Win for measurement.

Furthermore, a thermistor TM5 located downstream of the radiator 4 in the first heat cycle (circulation flow path) HC1 is used as one of the third temperature measuring parts to measure the temperature inside this circulation flow path. It's okay. Note that measurement of the temperature of the piping using the thermistor TM5 may be added as a fourth condition (step) of the second water supply conditions.

In each of the second water supply conditions [S4-1], [S4-2], and [S4-3] that constitute the first judgment control above, if each condition is not satisfied (No), the control is Shifting to [S11] at the top of the flowchart in FIG. 4, "second temperature control" is executed. This second temperature control will be explained later.

Next, as mentioned above, all (in this example, the above three) second water supply conditions [S4-1], [S4-2], and [S4-3] that constitute the first determination control are satisfied. In other words, if all the determination results are [Yes], the control device 30 determines in [S5] that the elapsed time from the start of the first determination control is the same as the first determination control, as shown in FIG. The transition to the next step ([S6]) is waited until one waiting time (T1) is reached.

In the embodiment, this first standby time T1 is, for example, about two hours. The above-mentioned first waiting time T1 is based on the assumption that "water filling" will be carried out reliably thereafter, and the possibility of freezing will increase again due to sudden changes in the external environment within a short period of time. This is to confirm whether or not.

Therefore, when the predetermined first standby time T1 (2 hours) has elapsed while repeating the loop of the first determination control including [S5], the control device 30 performs the above-mentioned [S2] in [S6]. ], the flow device (ventilation fan 50) is stopped and the heating device (anti-freeze heater 60) is started, and the first temperature control is completed. Note that this first determination control loop may be set to repeat every 10 minutes, for example, during the first standby time T1.

Then, at the end [S7], water filling is performed, and the series of control flows is completed.

On the other hand, as mentioned earlier, as the first judgment control, one condition is However, if there is one that is not satisfied and the determination is [No], the control device 30 proceeds to the flow shown in FIG. 4 .

The flow in FIG. 4 consists of the second temperature control in [S11] and the second determination control in [S12] to [S14].

As described above, the second temperature control in [S11] is executed when even one of the three second water supply conditions forming the first determination control is not satisfied. The second temperature control differs from the first temperature control [S2] described above in that it warms the inside of the case 70 compared to the outside environment to prevent freezing, and then fills the case with water. That is, the second temperature control executes the operation stop of the flow device (ventilation fan 50) and the start of operation of the heating device (antifreeze heater 60).

In this way, by operating the heating device (antifreeze heater 60), it is possible to increase the temperature inside the housing and also to increase the temperature of the path through which water flows. Note that, similarly to the first temperature control described above, the stopping of the ventilation fan 50 and the operation of the antifreeze heater 60 are continuously executed until an instruction to end the second temperature control is given in [S15]. Thereby, the temperature (air temperature) inside the casing (case 70) can be raised to a temperature at which freezing does not occur.

Next, a second determination control is executed in which two third water supply conditions are determined in [S13-1] and [S13-2].

Specifically, as the first (1/2) third water supply condition, in [S13-1], the thermistor TM2, which is the second temperature measuring section, measures the temperature as in the second water supply condition [S4-1]. It is determined whether the temperature (air temperature) Y (° C.) inside the case 70 is equal to or higher than a predetermined fifth temperature (hereinafter referred to as fifth set temperature Y2 (° C.)).

In the embodiment, this fifth set temperature Y2 may be the same as the second predetermined temperature Y1, or may be a different temperature.

In [S13-1], if the temperature Y inside the case 70 is [Yes] equal to or higher than the fifth set temperature Y2, the control device 30 determines that the temperature inside the case has risen to a temperature where there is no risk of freezing. Then, the process proceeds to the second (2/2) determination of the third water supply condition.

On the other hand, if the temperature Y is lower than the fifth set temperature Y2 (No) in [S13-1], it is determined that further heating inside the housing by the heating device (antifreeze heater 60) is necessary. Then, the loop is repeated and the process waits until the temperature Y becomes equal to or higher than the fifth set temperature Y2, that is, until the third water supply condition in [S13-1] is satisfied.

Next, as the second (2/2) third water supply condition [S13-2], the thermistor TM3, which is one of the third temperature measurement units, measures the temperature as in the second water supply condition [S4-3]. It is determined whether the temperature W (°C) inside the heat storage tank 3 is equal to or higher than a predetermined sixth temperature (hereinafter referred to as the sixth set temperature W2 (°C)).

In the embodiment, this sixth set temperature W2 may be the same as the third predetermined temperature W1, or may be a different temperature.

In [S13-2], if the temperature W in the heat storage tank 3 is [Yes] equal to or higher than the sixth set temperature W2, the control device 30 determines that the temperature has risen to a temperature where there is no risk of freezing even if water is supplied to the tank 3. After determining that, the process proceeds to [S14], where water supply is waited for.

On the other hand, in [S13-2], if the temperature W is less than the sixth set temperature W2 (No), the temperature of the tank to which water is supplied by the heating device (antifreeze heater 60) is insufficiently raised. Then, the loop is repeated and the process waits until the temperature W becomes equal to or higher than the sixth set temperature W2, that is, until the second third water supply condition in [S13-2] is satisfied.

Next, if all (in this example, the above two) third water supply conditions [S13-1] and [S13-2] constituting the second judgment control are satisfied, that is, all the judgment results are [Yes. ], in [S14], the control device 30 performs the next step ([S15]) until the elapsed time after all the third water supply conditions are cleared reaches the second standby time (T2). and [S16]).

Note that in the embodiment, the second standby time T2 can be set to be shorter than the first standby time T1 described above. For example, the second standby time T2 can be set to about 10 minutes. This time allows the antifreeze heater 60 to heat the water inside the housing and water tank beyond the third water supply condition, making it possible to ensure that the temperature has reached a temperature at which freezing will not occur. .

Therefore, when the predetermined second standby time T2 (10 minutes) has elapsed while repeating the second determination control loop including [S14], the control device 30 ends the second temperature control in [S15]. , the second determination control ends in [S16].

Then, as indicated by arrow (B) in the flowchart, the three temperature controls [S4-1], [S4-2], and [S4-3] are performed via the first temperature control [S2] shown in FIG. The process returns to the first determination control in which the second water supply condition is determined. Note that, at this point, it is considered that the antifreeze heater 60 described above has heated each part inside the casing to a temperature at which freezing does not occur. Therefore, the first temperature control is executed again, and the three second water supply conditions forming the first determination control [S5-1], [S5-2], and [S5-3] are determined.

With the above configuration, the fuel cell device 100 of the embodiment can suppress the occurrence of freezing and can fill the water tank with water.

As described above, the fuel cell device 100 receives an "instruction" to start water filling by a user, etc. by pressing a button on an operation panel or operating a switch on a maintenance panel, according to the second water supply condition. It is stored as a confirmation request, a first judgment control execution instruction, or a judgment request.

Using this record, if the water tank is not filled with water for a long time, such as after 72 hours have passed since the above-mentioned button was pressed, information on the occurrence of the event (water not being filled) can be obtained. may be communicated to external parties such as users and administrators through a display device (not shown) included in the control device 30, the aforementioned operation panel, a display on a maintenance panel, etc.

1 Fuel cell module 2 Heat exchanger 3 Heat storage tank 6 Reformed water tank 30 Control device 50 Ventilation fan 60 Antifreeze heater 70 Case 100 Fuel cell device K1, K2 Water supply flow path TM Thermistor

Claims (8)

A casing and
a fuel cell disposed within the housing;
a water supply channel connected to the water supply source;
A water tank that stores water necessary for fuel cell operation;
a first temperature measurement section that measures outside temperature;
a second temperature measurement unit that measures the temperature inside the housing;
a third temperature measurement unit that measures the temperature of at least one of the water tank and the water supply flow path;
comprising a control device;
The control device includes:
A predetermined first temperature set in relation to the outside air temperature measured by the first temperature measuring section is used as a first water supply condition, and each temperature measured by the second temperature measuring section and the third temperature measuring section is set as a first water supply condition. The set temperature set in relation to the temperature is used as the second water supply condition,
executing the determination of the first water supply condition, and if the first water supply condition is not satisfied, waiting for water supply to the water tank;
Thereafter, when there is a request for confirmation of the second water supply condition, the fuel cell device executes determination of the second water supply condition as first determination control. The fuel cell according to claim 1, wherein the second water supply condition includes a plurality of set temperatures, and at least one of the set temperatures is set to be lower than the first temperature in the first water supply condition. Device. A heating device that heats the inside of the casing;
a flow device that flows air within the housing, and the control device, before executing the first determination control,
3. The fuel cell device according to claim 1, wherein the first temperature control includes stopping the heating device and driving the flow device. The control device, when at least one condition is not satisfied among the plurality of conditions constituting the second water supply condition,
4. The fuel cell device according to claim 3, wherein the second temperature control includes stopping the flow device and activating the heating device. The control device includes:
a predetermined second temperature set in relation to the temperature measured by the second temperature measurement section; and a predetermined third temperature set in relation to the temperature measured by the third temperature measurement section. A plurality of predetermined temperatures including, as a third water supply condition,
The fuel cell device according to claim 4, wherein after execution of the second temperature control, at least one condition in the third water supply condition is determined as second determination control. The fuel cell device according to claim 5, wherein the control device executes the first determination control when all conditions forming the third water supply condition are satisfied in the second determination control. The first determination control includes a first standby time that waits after all conditions constituting the second water supply condition are satisfied,
The second determination control includes a second standby time that waits after all conditions constituting the third water supply condition are satisfied,
The fuel cell device according to claim 6, wherein the second standby time is shorter than the first standby time. If water is not supplied to the water tank even after a predetermined period of time has elapsed after the request for confirmation of the second water supply condition is received, the control device externally reports information on the occurrence of the event. , the fuel cell device according to any one of claims 1 to 7.