Indian Patents. 226821:FLOW MEASUREMENT AND CONTROL SYSTEM FOR SOLAR WATER HEATER/AIR HEATER SYSTEM

Title of Invention	FLOW MEASUREMENT AND CONTROL SYSTEM FOR SOLAR WATER HEATER/AIR HEATER SYSTEM
Abstract	N/A

Full Text	FORM - 2 THE PATENTS ACT, 1970 ( 39 of 1970 ) PROVISIONAL / COMPLETE SPECIFICATION SECTION 10 TITLE " FLOW MEASUREMENT AND CONTROL SYSTEM FOR SOLAR WATER HEATER/AIR HEATER SYSTEM" APPLICANT 1) AGASHE S.D., an Indian national, of Head of Instrumentation and Control Department Government College of Engineering Pune, Shivaji Nagar 411 005; and 2) MOHOKAR SWAPNIL D, an Indian national, of C/o D R Mohokar, 6th New Bhagwat Plots, Near Tare's Hospital, Akola 444001 The following specification particularly describes the nature of the invention and the manner in which it is to be performed The present invention relates to flow measurement and control system for solar water heater/air heater system. Solar water heater control systems are known but such control systems suffer from more than one disadvantages. Some of those disadvantages of the known solar water heater system installed in common for a society or an apartment suffer from following problems- • Lack of control or quantity of hot water consumed by each Consumer. • • Consumption of hot water in the evening by the consumers lowering the temperature of already heated water during the daytime thus hampering the performance of the overall system for the next day. For Cold-water distribution system following problem is faced. Lack of control on quantity of cold water consumed by each consumer. To overcome the above-mentioned disadvantages following methods are adapted • With mutual understanding among the consumers, quantity of hot water consumed by each consumer is controlled. • Increase the capacity of the system so as to meet the requirement of each consumer. • Have a control valve in the main supply header, which is opened for a fix time during the day thus preventing the consumption of hot water in the evening and lowering the temperature of hot water. - 2 - An object of the present invention is to provide a measured quantity of hot/cold water for each consumer and control it as per his daily predefined amount of hot water allotted to him. Another object of the present invention is to prevent the consumption of hot water in the evening by the consumers so as to prevent cold water being added to already heated water. Thus to have a system that will make optimum utilization of hot/cold water and solar energy. The present invention provides a flow measurement and control system for solar water / air heater system essentially comprising a measurement system and a control system, said measurement system comprises a turbine type water meter coupled with a gear train of mechanical counter, a semicircular metal disk attached to one of said gears, a temperature sensor used to detect temperature of hot water to be supplied, a clock of counter being provided with preset count as per the requirement of consumer, when count reaches to present count it gives control pulse to said control circuitry; said control circuitry being provided with a real time clock (RTC), a combination logic and control pulses from a sequential logic. To meet the requirements of hot / cold water of each consumer, the flow of hot / cold water to the consumer must be measured, compared with predefined count (liters) and control it accordingly using solenoid valve. - 3 - The present invention is described hereinbelow in detail with reference to the accompanying drawings, wherein - Fig. 1 shows the block diagram of the measurement and control system for hot water alongwith solar water heater system. Fig.2 shows the measurement and control system for cold water. The measurement and control system as shown in Fig. 1 consists of two parts. 1. Measurement system; and 2. Control system. Measurement system hardware description: To measure hot / cold water flow, turbine type water meter is used. Water meter works on principle of magnetic coupling which couples the rotation of turbine to the gear train of mechanical counter. When water - 4 - flows through the water meter the turbine rotates, these rotations of the turbine are coupled to the gear train which increments the count of mechanical counter. Now to convert rotations of gear into electronics pulses, a semicircular metal disk is attached to one of the gear. The disk rotates within the slot of the slotted opto-isolator. When water flows through the meter the disk rotates and gives the output pulses of some voltage. Temperature sensor is used to detect temperature of hot water supplied to the consumer. If the temperature is below set point value then water metering will not start till set point temperature is reached. Once set point temperature is reached pulses from meter are applied to clock of the counter. In case of cold water system temperature sensor is not used. Before applying to counter these pulses requires waveshaping to make them a perfect square wave. The waveshaped pulses are applied to clock of the counter which increments its count by one liter for every predefined number of pulses. The counter compares the count with preset count that is predefined requirement of each consumer. When count reaches to the preset count it gives the control pulse to the control circuitry. The control circuitry is described in the next section. Control circuitry: There are two conditions when control action needs to be taken. First when counter over flows, and second when Real Time Clock (RTC) gives a signal pulse at a predefined time. Therefore control circuit consists of a Real Time Clock (RTC), combinational logic, and control pulses from a sequential logic. - 5 - Depending on the accuracy required, in counter design first we go for a divide by "N" counter. Further depending upon requirement of the user the predefined count in number of liters is set using jumper settings. The counter compares the pulse count with the set count value by the jumpers at controller pins and when that is reached it gives a pulse to the combinational logic. RTC requires an external clock and is battery backed up so as to run in power failure cases. At certain predefined conditions, RTC gives control pulses to the combinational logic. For example morning 6'o clock global opening and evening 6'o clock global closures; Combinational logic is designed in such a way so as to generate a control pulse on fulfillment of any of the conditions from counter or RTC. These pulses are used \o drive a solenoid valve. The current amplification is done before providing pulses from controller to solenoid. Final control is obtained by ON-OFF action of the solenoid valve. Solenoid valve used here is designed using normal gate valve by mounting a coil on its plunger. The coil operates on some voltage. As solenoid valve is operating continuously, its power consumption is an important criterion in designing. That is why mechanical locking arrangement is done. On application of fix duration pulse the valve is switched ON or OFF and it gets locked in that position. So solenoid consumes power at switching time only and thus power consumption is reduced. The invention described hereinabove is only by way of example, any improvement or modification thereof which is within the knowledge of a person skilled in the art is intended to be covered within the scope of the present invention. 6 WE CLAIM: 1. A flow measurement and control system for solar water / air heater system essentially comprising a measurement system and a control system, said measurement system comprises a turbine type water meter coupled with a gear train of mechanical counter, a semicircular metal disk attached to one of said gears, a temperature sensor used to detect temperature of hot water to be supplied, a clock of counter being provided with preset count as per the requirement of consumer, when count reaches to present count it gives control pulse to said control circuitry; said control circuitry being provided with a real time clock (RTC), a combination logic and control pulses from a sequential logic. 2. A flow measurement and control system as claimed in Claim 1 wherein said water meter works on the principle of magnetic coupling and the rotation of turbine are coupled to said gear train which increases the count of mechanical counter. 3. A flow measurement and control system as claimed in Claim 2 wherein a semicircular metal disk is attached to one of said gear. 4. A flow measurement and control system as claimed in Claim 1 wherein said RTC is provided with an external clock and is backed by a battery for an emergency. - 7 - 5. A flow measurement and control system substantially as herein described and as illustrated in the drawing accompanying the Provisional Specification. Dated this 1st day of July 2004. - 8 -

Full Text

FORM - 2
THE PATENTS ACT, 1970
( 39 of 1970 )
PROVISIONAL / COMPLETE SPECIFICATION SECTION 10
TITLE
" FLOW MEASUREMENT AND CONTROL SYSTEM FOR SOLAR WATER HEATER/AIR HEATER SYSTEM"
APPLICANT
1) AGASHE S.D., an Indian national, of Head of Instrumentation and Control Department Government College of Engineering Pune, Shivaji Nagar 411 005; and 2) MOHOKAR SWAPNIL D, an Indian national, of C/o D R Mohokar, 6th New Bhagwat Plots, Near Tare's Hospital, Akola 444001
The following specification particularly describes the nature of the invention and the manner in which it is to be performed

The present invention relates to flow measurement and control system for solar water heater/air heater system.
Solar water heater control systems are known but such control systems suffer from more than one disadvantages. Some of those disadvantages of the known solar water heater system installed in common for a society or an apartment suffer from following problems-
• Lack of control or quantity of hot water consumed by each Consumer.

•
•

Consumption of hot water in the evening by the consumers lowering the temperature of already heated water during the daytime thus hampering the performance of the overall system for the next day.
For Cold-water distribution system following problem is faced.
Lack of control on quantity of cold water consumed by each consumer.

To overcome the above-mentioned disadvantages following methods are adapted
• With mutual understanding among the consumers, quantity of hot water consumed by each consumer is controlled.
• Increase the capacity of the system so as to meet the requirement of each consumer.
• Have a control valve in the main supply header, which is opened for a fix time during the day thus preventing the consumption of hot water in the evening and lowering the temperature of hot water.
- 2 -

An object of the present invention is to provide a measured quantity of hot/cold water for each consumer and control it as per his daily predefined amount of hot water allotted to him.
Another object of the present invention is to prevent the consumption of hot water in the evening by the consumers so as to prevent cold water being added to already heated water.
Thus to have a system that will make optimum utilization of hot/cold water and solar energy.
The present invention provides a flow measurement and control system for solar water / air heater system essentially comprising a measurement system and a control system, said measurement system comprises a turbine type water meter coupled with a gear train of mechanical counter, a semicircular metal disk attached to one of said gears, a temperature sensor used to detect temperature of hot water to be supplied, a clock of counter being provided with preset count as per the requirement of consumer, when count reaches to present count it gives control pulse to said control circuitry; said control circuitry being provided with a real time clock (RTC), a combination logic and control pulses from a sequential logic.
To meet the requirements of hot / cold water of each consumer, the flow of hot / cold water to the consumer must be measured, compared with predefined count (liters) and control it accordingly using solenoid valve.
- 3 -

The present invention is described hereinbelow in detail with reference to the accompanying drawings, wherein -
Fig. 1 shows the block diagram of the measurement and control system for hot water alongwith solar water heater system.
Fig.2 shows the measurement and control system for cold water.
The measurement and control system as shown in Fig. 1 consists of two parts.
1. Measurement system; and
2. Control system.
Measurement system hardware description:
To measure hot / cold water flow, turbine type water meter is used. Water meter works on principle of magnetic coupling which couples the rotation of turbine to the gear train of mechanical counter. When water
- 4 -

flows through the water meter the turbine rotates, these rotations of the turbine are coupled to the gear train which increments the count of mechanical counter.
Now to convert rotations of gear into electronics pulses, a semicircular metal disk is attached to one of the gear. The disk rotates within the slot of the slotted opto-isolator. When water flows through the meter the disk rotates and gives the output pulses of some voltage.
Temperature sensor is used to detect temperature of hot water supplied to the consumer. If the temperature is below set point value then water metering will not start till set point temperature is reached. Once set point temperature is reached pulses from meter are applied to clock of the counter. In case of cold water system temperature sensor is not used. Before applying to counter these pulses requires waveshaping to make them a perfect square wave.
The waveshaped pulses are applied to clock of the counter which increments its count by one liter for every predefined number of pulses. The counter compares the count with preset count that is predefined requirement of each consumer.
When count reaches to the preset count it gives the control pulse to the control circuitry. The control circuitry is described in the next section.
Control circuitry:
There are two conditions when control action needs to be taken. First when counter over flows, and second when Real Time Clock (RTC) gives a signal pulse at a predefined time.
Therefore control circuit consists of a Real Time Clock (RTC), combinational logic, and control pulses from a sequential logic.
- 5 -

Depending on the accuracy required, in counter design first we go for a divide by "N" counter. Further depending upon requirement of the user the predefined count in number of liters is set using jumper settings. The counter compares the pulse count with the set count value by the jumpers at controller pins and when that is reached it gives a pulse to the combinational logic.
RTC requires an external clock and is battery backed up so as to run in power failure cases. At certain predefined conditions, RTC gives control pulses to the combinational logic. For example morning 6'o clock global opening and evening 6'o clock global closures;
Combinational logic is designed in such a way so as to generate a control pulse on fulfillment of any of the conditions from counter or RTC. These pulses are used \o drive a solenoid valve. The current amplification is done before providing pulses from controller to solenoid.
Final control is obtained by ON-OFF action of the solenoid valve. Solenoid valve used here is designed using normal gate valve by mounting a coil on its plunger. The coil operates on some voltage. As solenoid valve is operating continuously, its power consumption is an important criterion in designing. That is why mechanical locking arrangement is done. On application of fix duration pulse the valve is switched ON or OFF and it gets locked in that position. So solenoid consumes power at switching time only and thus power consumption is reduced.
The invention described hereinabove is only by way of example, any improvement or modification thereof which is within the knowledge of a person skilled in the art is intended to be covered within the scope of the present invention.
6

WE CLAIM:
1. A flow measurement and control system for solar water / air heater system essentially comprising a measurement system and a control system, said measurement system comprises a turbine type water meter coupled with a gear train of mechanical counter, a semicircular metal disk attached to one of said gears, a temperature sensor used to detect temperature of hot water to be supplied, a clock of counter being provided with preset count as per the requirement of consumer, when count reaches to present count it gives control pulse to said control circuitry; said control circuitry being provided with a real time clock (RTC), a combination logic and control pulses from a sequential logic.
2. A flow measurement and control system as claimed in Claim 1 wherein said water meter works on the principle of magnetic coupling and the rotation of turbine are coupled to said gear train which increases the count of mechanical counter.

3. A flow measurement and control system as claimed in Claim 2 wherein a semicircular metal disk is attached to one of said gear.
4. A flow measurement and control system as claimed in Claim 1 wherein said RTC is provided with an external clock and is backed by a battery for an emergency.
- 7 -

5. A flow measurement and control system substantially as herein described and as illustrated in the drawing accompanying the Provisional Specification.
Dated this 1st day of July 2004.
- 8 -

FLOW MEASUREMENT AND CONTROL SYSTEM FOR SOLAR WATER HEATER/AIR HEATER SYSTEM

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