A portable system for on-site measurement of thermal efficiency of gas-based burner of cooking stove

Abstract

The present invention provides portable thermal efficiency testing system for gas-based burner, more particularly the one that is portable and compact machine for testing and measuring thermal efficiency of LPG based burner of household cooking stove using domestic cylinder with regulator at consumers premise. The device is portable to be easily carried to test the thermal efficiency of domestic stoves at household premises operable by 5 volt battery. Thermal efficiency tester comprises mass flow meter (11) and pressure transmitter (12). Consumed gas will flow through the pressure transmitter (12) and mass flow meter (11). A microcontroller (13) will be integrated for monitoring the system and as well as captured the data, connected with a thermocouple (9), pressure transmitter (12), mass flow meter (11) and an LCD display (14). The device is compact and affordable to benefit consumers towards ensuring economic, safe and efficient operation of cooking stoves.

Description

[0001] TITLE: A PORTABLE SYSTEM FOR ON-SITE MEASUREMENT OF THERMAL EFFICIENCY OF GAS-BASED BURNER OF COOKING STOVE.

[0002] FILED OF THE INVENTION

[0003] The present invention relates to a portable system for thermal efficiency measurement of gas-based burner. More particularly, the present invention provides a portable and compact machine for testing and measuring thermal efficiency of LPG based burner of household cooking stove using domestic cylinder with regulator at consumer premise. The proposed device is portable and can be easily carried to test the thermal efficiency of domestic stoves at household premises and this also operated by 5volt battery so there is no chance of fire hazards. The device is compact and affordable and can be procured by consumers through dealers of gas and oil companies. This will benefit consumers to ensure economic, safe and efficient operation of cooking stoves.

[0004] BACKGROUND OF THE INVENTION

[0005] Considering the huge number of LPG stoves used by domestic and commercial consumers, the efficient operation of the burners of such gas-based stoves particularly ensuring the desired thermal efficiency recommended by manufacturers is important, not only for cost benefit of consumers but also saving scarce and costly resource fuel. Prolonged use of such stoves with gas based burners and normal wear and tear reduces its thermal efficiency as compared to that claimed by manufacturers at the time of first installation. Also defective and wornout burners may cause poor heat transport and chances of flashback. Hence, on-site testing and monitoring the operational thermal efficiency of gas based burner / stove is necessary at periodic intervals, to decide on servicing or replacement based on result of such tests.

[0006] The currently available Thermal Efficiency Testing Machine, although precise, is not well-suited for household testing due to its large size and laboratory-oriented design[Refer Fig. 3]. To conduct such tests at home, a high precision weighing scale with a least count accuracy of 100 mg is necessary to measure the gas consumption of the stove from a specific small cylinder weighing 10kg. However, standard laboratory based weighing scales are inadequate for this task as they lack the capacity to accurately measure the weight of a domestic cylinder (approximately 30 kg gross weight) with the required 100 mg accuracy. Furthermore, transporting the laboratory-based Thermal Efficiency Tester (TET) to households for checking stove efficiency is challenging. Over time, gas stoves experience decreased efficiency without users being aware, resulting in the depletion of natural resources for oil companies (LPG, PNG, CNG, and others). Additionally, users suffer financial losses due to the reduced efficiency of their stoves.

[0007] In prior art (CN209841092U), the device for testing energy efficiency of gas oven is not portable, Thermal efficiency testing cannot be done at consumer premises of LPG stove user. Programmable logic controller is used to calculate thermal efficiency.

[0008] The present invention provides a device that will be portable and easily carried to test the thermal efficiency of domestic stoves at household premises and this also operated by 5volt battery so there is no chance of fire hazards. OBJECTS OF THE INVENTION

[0009] The basic object of the present invention is directed to provide a portable system for thermal efficiency measurement of gas-based burner of cooking stoves.

[0010] A further object of the present invention is directed to provide a portable and compact machine for testing and measuring thermal efficiency of LPG based burner of household cooking stove using domestic cylinder with regulator at consumer premise.

[0011] A still further object of the present invention is directed to provide said portable system wherein instead of employing a precise weighing scale and laboratory-based designed instrument, a high-precision mass flow meter (57mg list count) is utilized in the portable device to measure gas consumption from domestic household gas cylinders (approximately 30 kg gross weight) for determining the stove's thermal efficiency.

[0012] A still further object of the present invention is directed to provide said portable system which is a easily available and low cost testing instrument to be provided by oil and gas company dealers, so that household user can assess the thermal efficiency of their used stove through their LPG / Gas service provider, enabling them to take necessary action.

[0013] A still further object of the present invention is directed to provide said portable system to measure thermal efficiency of domestic LPG stoves that not only helps save financial losses for domestic users but also contributes to conserving the natural resources of gas and oil companies. SUMMARY OF THE INVENTION

[0014] The basic aspect of the present invention is directed to a portable thermal efficiency testing system for gas based burners comprising: a mass flow meter; a pressure transmitter; said mass flow meter and said pressure transmitter operatively connected to a supply gas regulator via an incoming supply gas pipeline for measuring the supply gas mass flow and pressure; said gas based burner to be tested operatively connected to an output of said incoming supply gas pipeline ahead of its connect to said portable thermal efficiency tester; a water heating pan including a thermocouple with stirrer means for heating of specific amount of water on said gas based burner; a microcontroller means integrated for receiving operative data from (i) said thermocouple providing for measuring (a) the initial temp of water in said water heating pan after opening of regulator and burning of burner through ignition means and (b) upon reaching of pre-set water temperature and turning off of the gas supply regulator , (ii) said mass flow meter and (iii) said pressure transmitter based on the incoming gas supply during the said burner efficiency test and generating burner efficiency based on said microcontroller recorded inputs on:

[0015] G=Quantity of water in the vessel;

[0016] W=water equivalent of the vessel with stirrer and lid; t 2=final temperature of water; t 1= initial temperature of water;

[0017] M=gas consumption;

[0018] K= Calorific value of the gas.

[0019] A further aspect of the present invention is directed to said portable thermal efficiency testing system for gas based burners wherein said microcontroller includes processor means for computing efficiency following:

[0020] 100(G + lV)(t2- t,) E = - MK -

[0021] Where

[0022] E = thermal efficiency of the burner in percent,

[0023] G = quantity of water in the vessel in kg,

[0024] W = Water equivalent of vessel complete with stirrer and lid, ti = initial temperature of water in °C, t2 = final temperature of water in °C,

[0025] M = gas consumption in kg,

[0026] K = calorific value of gas in kcal / kg.

[0027] A still further aspect of the present invention is directed to said portable thermal efficiency testing system for gas based burners wherein said water heating pan comprises aluminium pan with its matching lid and said specific amount of water is as per IS 4246 or water weighing 3.7kg, 4.8kg, 6.1kg. A still further aspect of the present invention is directed to said portable thermal efficiency testing system for gas based burners which is operable on 5 volts battery and free of fire hazards.

[0028] A still further aspect of the present invention is directed to a method for testing the thermal efficiency for gas based burner involving the portable thermal efficiency testing system as described above comprising the steps of:

[0029] (i) providing a filled domestic cylinder for desired measuring of the thermal efficiency;

[0030] (ii)placing the domestic regulator on the SC valve of the said filled domestic cylinder;

[0031] (iii) connecting the incoming gas pipeline from output of domestic regulator to said portable thermal efficiency testing system such that the incoming gas passes through said mass flow meter and pressure transmitter;

[0032] (iv) connecting the outgoing gas pipeline between said output from said portable thermal efficiency testing system and said gas stove for supply of the incoming gas to said gas stove ahead of said portable thermal efficiency testing system;

[0033] (v) placing a water pan with specified water with lid thereon on the said gas stove for heating;

[0034] (vi) opening the said domestic regulator for gas flow to stove burner and lighting the burner for testing to commence with start of the portable thermal efficiency tester and involving the microcontroller for measuring the mass flow rate and pressure of the gas flow to burner;

[0035] (vii) heating the water in said pan such as to increase the initial temperature of water of 25°C to 28°C to higher temperature of 90°C to 95°C preferably about 90°C when the gas flow through said regulator is stopped;

[0036] (viii) recording the total gas consumption from said mass flow meter by said microcontroller; and

[0037] (ix) computing the efficiency following:

[0038] Where

[0039] E = thermal efficiency of the burner in percent,

[0040] G = quantity of water in the vessel in kg,

[0041] W = Water equivalent of vessel complete with stirrer and lid, ti = initial temperature of water in °C, t2 = final temperature of water in °C,

[0042] M = gas consumption in kg,

[0043] K = calorific value of gas in kcal / kg.

[0044] A still further aspect of the present invention is directed to said method wherein total gas consumption is recorded from the mass flow meter by the microcontroller precisely with said mass flow meter being a high-precision mass flow meter (57mg list count) providing a pulse per 57 mg gas consumption.

[0045] A still further aspect of the present invention is directed to said method wherein stirring of water is continued manually during heating until the maximum temperature is reached.

[0046] Another aspect of the present invention is directed to said method wherein the gas flow pressure is measured by said pressure transmitter in the range of 25 gf / cm2to 35gf / cm2preferably 30 gf / cm2recommended on basis of more than 201 / h gas flow.

[0047] Yet another aspect of the present invention is directed to said method wherein the system carry out performance monitoring as well as capturing the operating data, and computing and displaying the measured data and thermal efficiency of the burner computed based on the captured data on a LCD display panel.

[0048] The above and other aspects and advantages of the present invention are described hereunder in greater details with reference to following accompanying non limiting illustrative drawings.

[0049] BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

[0050] Figure 1 : shows the schematic drawing of complete system set-up for onsite thermal efficiency measurement of gas based burner of cooking stove involving a portable thermal efficiency tester according to present invention.

[0051] Figure 2: shows a photo-image of the actual experimental set-up of portable thermal efficiency tester connected to burner at consumer premise.

[0052] Figure 3: shows the prior art laboratory based thermal efficiency testing facility having large size needing high precision weighing scale with a least count accuracy of 100 mg is necessary to measure the gas consumption of the stove and hence not suitable for testing at consumer premise.

[0053] DETAILED DESCRIPTION OF THE INVENTION WITH REFERENCE TO THE ACCOMPANYING DRAWINGS.

[0054] The present invention herein discloses a device that will be portable and easily carried to test the thermal efficiency of domestic stoves at household premises and this also is operated by 5volt battery so there is no chances of fire hazards. Instead of employing a precise weighing scale and laboratory-based designed instrument, a high-precision mass flow meter (57mg list count) will be utilized in our proposed device to measure gas consumption from domestic household gas cylinders (approximately 30 kg gross weight) for determining the stove's thermal efficiency.

[0055] Accompanying Figure 1 shows the schematic drawing of complete system set-up for onsite thermal efficiency measurement of gas based burner of cooking stove involving a portable thermal efficiency tester according to present invention having part number based reference numerals as per the following: SC valve (1), Regulator (2), Incoming hose (3), Outgoing hose (4), Gas stove (5), stove burner (6), pan with lid (7), stirrer (8), thermocouple (9), thermocouple stand (10), mass flow meter (11), pressure transmitter (12), microcontroller (13), LCD display (14).

[0056] The system of the present invention as illustrated in Figure 1, will measure the thermal efficiency following this working mechanism: The filled domestic cylinder will be used to measure the thermal efficiency of the household user at their premises. The domestic regulator (2) will be placed properly on the SC valve (1) of the cylinder. The incoming hose (3) from the output of the domestic regulator will be connected to the portable thermal efficiency tester (TET) input port. Inside the portable thermal efficiency tester, there is a mass flow meter (11) and pressure transmitter (12). The consumed gas will flow through the pressure transmitter (12) and mass flow meter (11). A microcontroller (13) will be integrated for monitoring the system and as well as captured the data, connected with a thermocouple (9), pressure transmitter (12), mass flow meter (11) and an LCD display (14). The outgoing hose (4) will be connected between the gas stove (5) and portable Thermal Efficiency Tester (TET). There will be a specific aluminum pan (7) with its lid (As per IS 4246). The aluminum pan, filled with specific amount of water (As per IS 4246), will be boiled on the gas stove (4). The thermocouple (9) and manual stirrer (8) will be immersed inside the pan filled with water. After making this setup, the domestic regulator (2) needs to be opened for gas flow to the stove (5). Ignition should be done on the stove burner (6) using a gas lighter and the start button should be pressed on the portable thermal efficiency tester immediately after successful ignition. The temperature of the water will increase accordingly. The initial temperature of the used water (25° to 28° C) and LPG flow pressure (30 gf / cm2) will be automatically captured by the portable thermal efficiency tester. When water temperature reaches 80° C, stirring of the water should be done manually. When the temperature reaches 90° C, the gas flow should be stopped by changing the position of the domestic pressure regulator (2) to "Off" position, and stirring should be continued manually until the maximum temperature is reached. The total gas consumption will be recorded from the mass flow meter (11) by the microcontroller (13) properly. The mass flow meter (11) provides a pulse per 57 mg gas consumption. The efficiency (%) will be automatically calculated as per the following formula (1) -

[0057] 100(G+W)(t2— ti) c — -

[0058] MK (1) where E = thermal efficiency of the burner in percent,

[0059] G = Quantity of water in the vessel in Kg,

[0060] W = Water equivalent of the vessel complete with stirrer and lid, t2 = Final temperature of water in °C, ti = Initial temperature of water in °C,

[0061] M = Gas consumption in kg,

[0062] K = Calorific value of the gas in kcal / kg.

[0063] The following example illustrates the working of the device according to present invention: Accompanying Figure 2 shows a photo-image of the actual experimental set-up of portable thermal efficiency tester connected to gas based burner at consumer premise.

[0064] 5 Example:

[0065] Experimental trials were conducted to evaluate the effectiveness of the thermal efficiency measurement of gas burner using the invented system was carried out by taking measured weight of Water in the vessel and heating to desired temperature where Calorific value of the 10 gas (K) = 10900 kcal / kg, and the results are tabulated as follows:

[0066] Table 1:

[0067] The Portable Thermal Efficiency Tester according to present invention impacts the Socio-Economy by saving fuel / gas consumption and gives 15 a proper knowledge to the household user about their consumption of LPG, fuel and save money. On the other hand, stove and burner manufacturer gets an opportunity to sell their product more due to there will be a big chance of replacement the less efficient LPG stove by household user which helps economical growth of the industries.

[0068] 20 The instrument is also cost friendly that is why Oil Company will purchase for their each distributor.

Claims

Claims:

1. A portable thermal efficiency testing system for gas based burners comprising: a mass flow meter 11; a pressure transmitter 12; said mass flow meter 11 and said pressure transmitter 12 operatively connected to a supply gas regulator 2 via an incoming supply gas pipeline 3 for measuring the supply gas mass flow and pressure; said gas based burner 6 to be tested operatively connected to an output 4 of said incoming supply gas pipeline ahead of its connect to said portable thermal efficiency tester TET; a water heating pan 7 including a thermocouple 9 with stirrer 8 means for heating of specific amount of water on said gas based burner 6; a microcontroller means 13 integrated for receiving operative data from (i) said thermocouple providing for measuring (a) the initial temp of water in said water heating pan after opening of regulator and burning of burner through ignition means and (b) upon reaching of pre-set water temperature and turning off of the gas supply regulator, (ii) said mass flow meter 11 and (iii) said pressure transmitter 12 based on the incoming gas supply during the said burner efficiency test and generating burner efficiency based on said microcontroller recorded inputs on:G=Quantity of water in the vessel;W=water equivalent of the vessel with stirrer and lid;12=final temperature of water;1 1= initial temperature of water;M=gas consumption;K= Calorific value of the gas.

2. The portable thermal efficiency testing system for gas based burners as claimed in claim 1 wherein said microcontroller 13 with LCD display 14 includes processor means for computing efficiency following:where E = thermal efficiency of the burner in percent,G = Quantity of water in the vessel in Kg,W = Water equivalent of the vessel complete with stirrer and lid, t2 = Final temperature of water in °C, ti = Initial temperature of water in °C,M = Gas consumption in kg,K = Calorific value of the gas in kcal / kg.

3. The portable thermal efficiency testing system for gas based burners as claimed in anyone of claims 1 or 2 wherein said water heating pan comprises aluminium pan with its matching lid 7 and said specific amount of water is as per IS 4246 or water weighing 3.7kg, 4.8kg, 6.1kg.

4. The portable thermal efficiency testing system for gas based burners as claimed in anyone of claims 1 to 3 which is operable on 5 volts battery and free of fire hazards.

5. A method for testing the thermal efficiency for gas based burner involving the portable thermal efficiency testing system as claimed in anyone of claims 1 to 4 comprising the steps of:(i) providing a filled domestic cylinder for desired measuring of the thermal efficiency;(ii)placing the domestic regulator 2 on the SC valve 1 of the said filled domestic cylinder;(iii) connecting the incoming gas pipeline 3 from output of domestic regulator 2 to said portable thermal efficiency testing system TET such that the incoming gas passes through said mass flow meter 11 and pressure transmitter 12;(iv) connecting the outgoing gas pipeline 4 between said output from said portable thermal efficiency testing system and said gas stove 5 having burner 6 for supply of the incoming gas to said gas stove and burner ahead of said portable thermal efficiency testing system;(v) placing a water pan with specified water with lid 7 thereon on the said gas stove for heating;(vi) opening the said domestic regulator 2 for gas flow to stove burner 6 and lighting the burner for testing to commence with start of the portable thermal efficiency tester and involving the microcontroller 13 for measuring the mass flow rate and pressure of the gas flow to burner;(vii) heating the water in said pan such as to increase the initial temperature of water of 25° to 28°C to higher temperature of 90° to 95° C preferably about 90°C when the gas flow through said regulator is stopped;(viii) recording the total gas consumption from said mass flow meter by said microcontroller 13; and(ix) computing the efficiency following:100(G + W)(t2-E =- MK -where E = thermal efficiency of the burner in percent,G = Quantity of water in the vessel in Kg,W = Water equivalent of the vessel complete with stirrer and lid, t2 = Final temperature of water in °C, ti = Initial temperature of water in °C,M = Gas consumption in kg,K = Calorific value of the gas in kcal / kg.

6. The method as claimed in claim 5 wherein total gas consumption is recorded from the mass flow meter by the microcontroller 13 precisely with said mass flow meter 11 being a high-precision mass flow meter (57mg list count) providing a pulse per 57 mg gas consumption.

7. The method as claimed in claims 5 or 6 wherein stirring of water is continued manually during heating until the maximum temperature is reached.

8. The method as claimed in anyone of claims 5 to 7 wherein the gas flow pressure is measured by said pressure transmitter 12 in the range of 10 to 100 gf / cm2 preferably 30 gf / cm2.

9. The method as claimed in anyone of claims 5 to 8 wherein the system carry out performance monitoring as well as capturing the operating data, and computing and displaying the measured data and thermal efficiency of the burner computed based on the captured data on a LCD display panel.

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