Product Overview, Features, and Applications

What is the BP-201?

The Miura BP-201STA Boiler System Operation Panel, commonly referred to as the BP-201 or BP, is the master control and monitoring panel for a Miura multiple-boiler installation. It communicates over the Miura M-NET3 network to provide MI control and communications for the boiler system.

The BP-201 can control up to two boiler systems with as many as 18 boilers per system, for a maximum of 36 controlled boilers. Its MI control uses proportional distribution control to determine how many boilers should operate as steam demand and header pressure change.

In practical terms, the BP-201 serves three primary roles:

1. Multiple-boiler system control
2. Central equipment monitoring
3. System integration and communications

Depending on the system configuration, it can also provide feedwater and water-treatment control and integrated Miura Connect functionality.

Multiple-Boiler System Control

The BP-201 monitors steam pressure and automatically determines which connected boilers should operate based on system demand and the configured MI control settings. The training material describes the practical objective as maintaining the appropriate number of boilers online to respond to load changes while maintaining steam-header pressure.

Proportional Distribution Control

Rather than simply treating every boiler as an independent on/off device, the BP uses proportional distribution control. The controller divides the control-pressure zone and determines how many boilers should be firing at each pressure level. As header pressure changes, the controller adjusts the number of boilers in combustion.

MI control is configured around two important steam-output values:

• Maximum steam output, representing maximum steam consumption.
• Fluctuating steam output, representing anticipated steam-load fluctuations.

The BP then determines the controlled boilers and number of operating units using these settings together with the selected combustion-priority control mode.

Responding to Changing Steam Demand

The BP includes several strategies intended to improve response as steam load changes.

During boiler startup, boilers already firing can temporarily move to a higher combustion state while a standby boiler starts producing steam. During falling demand, the BP can favor keeping boilers at low fire rather than immediately placing them into standby. The control also manages boiler switching to avoid unnecessary starts or stops when the load is stable.

The BP can additionally use pressure-hold operation to maintain a standby boiler in a preheated condition without supplying steam, improving its readiness to respond to increasing system demand.

This functionality makes the BP especially valuable for applications where steam demand changes rapidly or significantly throughout the operating cycle.

Boiler Sequencing and Rotation

Another important BP-201 function is managing boiler operating priority.

The BP provides automatic priority rotation. Depending on configuration, rotation can occur after the boilers remain in standby for a defined period, after a selected number of hours or days, or according to a weekly schedule.

The BP also recognizes a boiler complete blowdown and temporarily increases that boiler's operating priority afterward. The specification identifies the purpose as rapidly restoring boiler-water concentration following the blowdown.

For users, this means boiler sequencing does not have to be managed manually as operating conditions change.

Multiple Control Patterns

A single steam system does not necessarily operate the same way throughout the day or week.

The BP-201 can store up to five MI control patterns, allowing different operating configurations to be established for different system requirements. Control-pattern selection can be initiated from the touchscreen or by external contact signals.

The available MI control settings include:

• Proportional distribution pressure settings
• Steam-output and operating-condition settings
• Upper- and lower-pressure alarm settings
• Load-following settings

The BP also includes a weekly program function. Up to five operating time bands can be configured for days of the week, and control-pattern selection can be linked to those programmed time bands.

This can be useful for facilities with predictable production schedules or distinct operating modes where boiler-system requirements change by shift, process, or time of day.

Central System Monitoring

The BP-201 is more than a boiler sequencer. It also acts as a centralized interface for the connected Miura system.

The touchscreen provides hierarchical monitoring of connected equipment, including supported:

• Steam boilers
• Water softeners
• Dissolved-oxygen removal equipment
• Colormetry equipment
• WP2 water-treatment controls
• Membrane and RO equipment
• Deaeration equipment
• Filtration equipment

Specific supported models and availability vary by equipment and region.

The BP visually differentiates system status:

• Green: Normal
• Red: Alarm
• Yellow: Caution or Notice

When monitored equipment produces an Alarm, Caution, or Notice, the touchscreen identifies the affected equipment and can display the error details and operating instructions.

Depending on system configuration, other operating information such as water level or feedwater volume can also be displayed.

Integrated Miura Connect Gateway

Current BP configurations may include Miura Connect functionality integrated into the BP panel. Miura Connect can natively monitor selected Miura devices on the M-NET3 network and provide real-time information to the central Miura Connect website. The specification identifies supported equipment examples including BL-based boilers, the BP master controller, MW water softeners, Colormetry units, and the WP2 water-treatment control panel.

What changed from earlier BP configurations?

With the updated configuration, the Miura Connect gateway is installed within the BP panel. As you noted, the gateway:

• Occupies one additional communication port on the BP's hub.
• Uses the 4G/Wi-Fi antenna located on top of the BP panel.

The current specification identifies the BP communications relay hub as an 8-port unit.

The exterior drawing also specifically identifies the antenna at the top of the BP as a Wi-Fi/cellular antenna supporting 3G/4G LTE communication, depending on BP model.

Application note: When laying out the M-NET3 network for a BP equipped with the integrated Miura Connect gateway, account for the gateway's use of one port on the eight-port communications hub, as well as one for the BP-201 CPU board, and another for the ML3 board. This leaves 5 available ports on a standard BP-201. This detail is particularly important when determining available connections for boilers and other network devices.

External Inputs and Outputs

The BP can also interface with other portions of the customer's control system through discrete inputs and outputs.

The standard BP provides 12 external contact inputs, including two pulse inputs, and these can be expanded to 28 inputs with an optional expansion board. It provides four standard external contact outputs, expandable to 20 outputs.

Supported input functions include:

• Earthquake detector
• Fuel-leakage signal
• Emergency stop by boiler system
• Systemwide standby
• Systemwide manual operation
• Control-pattern switching
• Two pulse inputs, such as signals from a feedwater flowmeter

Available output functions include:

• Alarm signals
• Boiler operating signals
• Feedback signals confirming receipt of emergency-stop, systemwide-standby, or systemwide-manual-operation commands

Important design consideration

The BP specification cautions that the expected input/output actions may not occur if the BP loses power or communications are defective. System designers should understand this behavior when integrating customer controls with the BP, particularly where an external signal is associated with an important boiler-system function.

The original BP training material similarly calls attention to this consideration for critical functions such as E-stop.

Optional Feedwater and Water-Treatment Control

When equipped with the optional WP2 water-treatment control unit, the BP can extend centralized control beyond the boilers themselves.

Available functions include:

• Feedwater-tank control
• MI chemical-feed control
• Condensate-related control
• MSR-W water-softener regeneration control
• Central monitoring of water-treatment equipment
• Information relay for water-treatment equipment

For feedwater applications, a tank water-level sensor can be connected to the control board to provide feedwater-tank level control. The system can also incorporate a bypass motor valve intended to maintain water supply to the feedwater tank if water-treatment equipment fails.

This capability makes the BP an important integration point when the boiler-room design incorporates Miura water-treatment equipment in addition to the boiler plant.

Alarm and System Monitoring

The BP can monitor multiple categories of system conditions, including:

MI control

• Steam pressure above upper limit
• Steam pressure below lower limit
• Low steam-supply capacity

Safety

• Earthquake detector
• Emergency stop
• Fuel-leakage detection
• Tremor-sensor operation

Sensors

• Steam-pressure sensor output errors
• Pressure-detector adjustment errors

Communications and internal system

• Boiler communication errors
• Monitored-equipment communication errors
• Control-board and memory errors
• Backup battery voltage
• Touch-panel errors

Additional feedwater, chemical-feed, and condensate-related conditions are available with the applicable equipment and settings. Some listed alarms depend on optional specifications or configuration.

Key Product Specifications

These values come from the current BP-201STA product specification; expansion-board options determine the higher I/O counts.

Notes:

1. Up to 2 systems can be controlled with 18 units per system
2. Contact inputs are 24 VDC, 10mA. Select normally-open contact (a-contact) input or normally-closed contact (b-contact) input.
   Pulses of maximum frequency of 500 Hz, input voltage of 24 VDC, and input current of 5.5 mA can be input to 2 contacts.
3. There are 12 standard inputs including 2 pulse inputs.
   The number of inputs can be increased up to 28 inputs if the expansion board option is selected. The number of pulse inputs cannot be increased. 
4. Contact rating is 30 VDC, 0.5 A (inductive load) 
5. There are 4 standard outputs. The number of outputs can be increased up to 20 outputs if the expansion board option is selected.
6. The power circuit breaker should be an earth leakage circuit breaker with overcurrent protection.
7. No freezing or condensation should occur. 
8. Dimensions exclude the eyebolts on top of the main unit and anchor mounting plate at the bottom of the main unit.
9. The steam pressure sensor specifications are shown below. 
   
10. The steam pressure switch specifications are shown below.
    

Typical Applications

The BP-201 should be considered when an application requires coordinated operation of multiple compatible Miura boilers, particularly where centralized boiler sequencing, load response, equipment monitoring, or integration with associated Miura equipment is desirable.

Typical applications include:

Multiple-boiler plants

Facilities operating several Miura boilers from a common steam header can use the BP to coordinate the operating boilers based on header pressure and steam demand.

Highly variable steam loads

Applications with significant load fluctuations can benefit from the BP's fluctuating-steam-output, low-fire, standby, and pressure-hold control concepts intended to maintain available response capacity.

Plants requiring centralized monitoring

The BP provides a common interface for viewing boiler and supported ancillary-equipment conditions rather than requiring the operator to check each individual device.

Integrated Miura boiler-room solutions

Systems incorporating Miura boilers, water treatment, feedwater equipment, and Miura Connect can use the BP as a central control and communications point.

Facilities with different operating schedules

Control patterns and weekly scheduling allow the boiler system's operating strategy to be adapted to different scheduled operating conditions.

Application and Design Considerations

Before specifying a BP-201, consider:

Boiler quantity and system arrangement
A BP supports up to two systems and 18 boilers per system.

M-NET3 network layout
Connected equipment quantity and cable-length restrictions may require an additional EN communications relay unit.

Miura Connect gateway
For BP panels equipped with the integrated gateway, allow for the additional hub-port connection and the top-mounted Wi-Fi/cellular antenna.

External controls
Determine which customer signals need to enter or leave the BP and whether the standard I/O capacity is sufficient. Expansion boards can increase the input and output capacity.

Water-treatment integration
Determine whether WP2 functions or DS-NET communications are required for the project.

Non-Miura boilers
The BP-201 does not provide MI control of non-Miura boilers.

Summary

The BP-201 is the central coordinator for a Miura multiple-boiler system. It combines boiler sequencing, pressure-based MI control, load-response management, boiler rotation, centralized monitoring, external I/O, optional water-system integration, and, on applicable current configurations, integrated Miura Connect connectivity.

The most important concept is that the BP should not be viewed simply as a boiler sequencer. It acts as a system-level controller and communications hub, allowing the boiler plant and compatible Miura ancillary equipment to operate as an integrated system.