Condensing boilers

Withdrawn) 1990 Safety of condensing boilers (2nd and 3rd family gases). Withdrawn, superseded by BS EN 677 1998... 

Spray recuperator. The principle of the spray recuperator is similar to that of the condensing boiler, and again is restricted to gas firing. In this case, the condensation... 

Additional guidance in the design of flues for condensing systems is given in the British Gas publication Installation Guide for High Efficiency (Condensing) Boilers — Industrial and Commercial Applications (lM/22). 

Warm water or low-, medium- or high-temperature hot water systems are categorized in Table 27.8. Warm water systems may use heat pumps, fully condensing boilers or similar generators, or reclaimed heat. In many cases the system design may incorporate an alternative heat generator for standby purposes or for extreme whether operation. Under such circumstances the system may continue to function at warm water temperatures or could operate at more conventional LTUW ones. 

Condensing boilers are now available for both gas- and oil-fired plant, the advantage of these being that the flue gases are further cooled down to below 100°C so that the latent heat available in the flue gas water vapor is recovered. The condensate has to be removed and the boiler capital cost is higher than for conventional plant. However, the boiler plant efficiency is increased to the order of 90 per cent, based upon the fuel gross calorific value. Where the flue gas exit temperatures are in excess of 200° C a further economy can be obtained by the provision of a spray recuperator in the case of gas and flue gas economizers for oil and coal. 

Domestic Burner Control (Fuel Burners, Gas Condensing Boilers)... 

An oil burner or gas condensing boiler which does not operate at its optimum setting will not only decrease in efficiency, but the concentration of CO, HC and the content of soot in the exhaust gas will also increase. A measure for the quality of combustion is the well-known (in the automotive industry) lambda- (2-) value (see also chapter 53.2.4). 

The chemical products from complete combustion of a hydrocarbon fuel are mainly C02 and H20 (vapor). Combustion of gaseous fuel in air can occur in two different modes - one where fuel and oxygen is mixed during the combustion process, and the other where fuel and air are premixed (gas condensing boilers) and the fuel concentration must be within the flammability limits. In general the premixed situation allows the fuel to burn faster, i.e. more fuel is consumed per unit time. 

Normally, after being heated, these streams are used in the boiler area (deaerator feedwater, cold return condensate, boiler feedwater, RO feedwater) or in the combustion chamber (air preheat). However, economizers can be used to recover and supply heat elsewhere, such as hot process water or hot utihty water, especially as used in the food processing and pulp/paper industries. Additionally, recovered flue gas waste heat can be used indirectly i.e., remote process streams can be heated locally with hot steam condensate, and then the cooled return steam condensate can be reheated in the flue gas economizer. An... 

In ammonium phosphate production and mixed and blend fertilizer manufacturing, one possibility is the integration of an ammonia process condensate steam stripping column into the condensate-boiler feedwater systems of an ammonia plant, with or without further stripper bottoms treatment depending on the boiler quality makeup needed. 

Methylene chloride Cooling tower blowdown. Steam condensate. Boiler Intake... 

This chapter deals with equipment types that are of most interest to a process engineer tubular and plate exchangers condensers boilers and calandrias extended surface equipment mechanically aided heat-transfer devices and tubular chemical reactors. Evaporators are described in Chap. 16. Information on all types of heat-exchange equipment is given in engineering texts and handbooks.i -= °... 

The commercial boiler market is moving toward high efficiency and condensing technology. Currently, highly efficient condensing boilers are making up 20-25% of the commercial boiler market and exceed the 90% efficiency barrier. 

Nano-sized particles are formed in larger concentrations in the flame region but are also strongly oxidized in the secondary oxidation region of the flame, and also in the high temperature flame confinement in a practical condensing boiler. 

Condensing technology is important in utility boilers not only for improving boiler efficiency, but also for reducing soot emissions. It has been demonstrated that in a gas appliance soot emissions can be reduced to half by the use of a condensing boiler [10]. 

The boiler is a product able to supply hot water in a central heating application. The appliance may be developed to provide the sanitary hot water. The performance parameters of the boiler are the nominal heating capacity in kW defined as full load mode and the nominal partial load capacity at 30% of nominal heating capacity. Tests are performed at standard conditions, which means supply plant temperatures outlet 80°C inlet 60°C and for condensing boilers, supply plant temperatures outlet 50°C and inlet 30°C. 

Condensing boiler When the product is designed to produce condense by combustion gas permanently, which recovers a large part of the water vapor contained in the combustion gases. 

A condensing boiler always has a nozzle for condense draining. 

Title EN 677 1998 en. Gas-fired central heating boilers. Specific requirements for condensing boilers with a nominal heat input not exceeding 70 kW. 

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