A kind of phase-change thermal storage energy-saving electric water heater
Technical field
The invention belongs to household electrical appliance technical field, particularly relate to a kind of phase-change thermal storage energy-saving electric water heater.
Background technology
Increasingly serious along with energy situation, power-saving technology has become the focus of each big water heater brand competition.At present the electric heater of main flow is a storage-type electric water heater, and it is energy-conservation to mainly include two aspects, the one, and heating process energy-conservation, the 2nd, insulating process energy-conservation, the former proportion in the water heater energy consumption is minimum, and the latter accounts for more than 97%.Therefore, the energy-saving design core starting point of water heater industry is mainly in the innovation of heat-insulation layer.
It is heat insulation that the insulation of storage-type electric water heater at present mainly relies on polyurethane foamed material to carry out.Polyurethane is the abbreviation that gathers amino methyl, every macromolecular compound common name polyurethane that on high polymer main chain, contains repetition-NHCOO-group.Polyurethane foam is the principal item of polyurethane, has unit weight intensity height, lightweight, long service life, excellent properties such as thermal conductivity factor is low, dimensional stability good, convenient formation, is to use the most extensive, the optimum heat-insulating material of combination property at present.Yet, use polyurethane heat-insulation to belong to passive heat insulation mode in essence, heat preserving method is single, and energy-saving effect has reached the limit at present, only if having novel insulation material and heat preserving method to occur.
Phase-change material is the field that research very enlivens aspect using energy source and material science both at home and abroad in recent years.Phase-change material can absorb heat (cold) amount or emit heat (cold) amount to environment, thereby realize the storage and the release of energy in its thing phase change process from environment.Owing to be to utilize latent heat of phase change, the energy storage density is usually than the high 1-2 one magnitude of sensible heat heat accumulation, and this means that also the volume of heat storage units under the identical condition will be far smaller than the sensible heat storage.Thereby phase-change material is used for the purpose that water heater can realize strengthening heat accumulation, energy savings.The existing water heater that uses phase-change heat-storage material basically all is in inner bag, to add phase-change material, like patent " phase-changing energy-storing solar water heater (ZL20060064881.6) ", is provided with accumulation of energy heat exchange inner bag, uses C
18H
42Paraffin is phase-change material; Patent " a kind of phase-change type electric heater (ZL0220996.7) " and for example; In the inner bag of electric heater, charge into phase-change material (paraffin) heat energy storage; In phase-change material, implant heat exchange element again, electrical heating elements is implanted in the phase-change material equally, and the first heating phase-change material in water heater energising back is to fusing; When needing hot water, let hot water pass through heat exchange element from the phase-change material draw heat.Yet the heat of transformation hydrophone that these are built-in compares with non-phase transformation product, and power savings advantages is also not obvious, does not promote so far.Tracing it to its cause, be because built-in phase-change material has compressed the volume of hot water on the one hand, and specific heat of water is very high, and water storage sensible heat can be compared with latent heat in wider temperature range, and is therefore energy-conservation and not obvious; On the other hand, phase-change material thermal conductivities such as paraffin are not high, and it is very low to rely on phase-change material to add hot water efficient fully.
Summary of the invention
The object of the present invention is to provide a kind of phase-change thermal storage energy-saving electric water heater; Use external phase-change material reservoir; Constitute composite heat-insulating layer with polyurethane foamed material, play the insulation effect of heat accumulation and heat insulation coupling, effectively reduce the effect of the energy consumption of storage-type electric water heater.
The present invention originally comprises, outer cover of water heater, heat-insulation layer, inner bag, magnesium rod, sewage draining exit, hot water outlet, cold water inlet, earth leakage circuit-breaker, temperature controller, electric heating tube; Heat-insulation layer between outer cover of water heater and the inner bag adopts the composite heat-insulating layer design, and composite heat-insulating layer is made up of polyurethane foam thermal insulation layer and phase-change thermal storage layer, realizes that through the dual insulation of heat accumulation-heat insulation coupling is machine-processed the degree of depth of storage-type electric water heater is energy-conservation.The polyurethane foam thermal insulation layer is between shell and phase-change thermal storage layer, and the phase-change thermal storage layer is close to the inner bag outside, composite heat-insulating layer gross thickness 25~45mm, and the phase-change thermal storage layer is 0.4~0.8 with polyurethane foam thermal insulation layer thickness ratio.
The phase-change thermal storage layer is formed through grand capsule method encapsulation by phase-change material, processes polylith sheet capsule compactness and is arranged in inner bladder outer wall placement (external), is close to the inner bag outside.Grand capsule is meant the capsule that is of a size of 1~1000mm.
The fusing point of phase-change material is 50~75 ℃ (the setting holding temperature than water heater is hanged down 0~10 ℃ for 60~75 ℃); Phase-change material is heptacosane, positive octacosane, positive nonacosane, positive melissane, positive hentriacontane, positive tritriacontane and the above-mentioned material mixture according to arbitrary proportion; Or be 1-hexadecanoic acid, 1-octadecanoid acid, 1-18 alcohol, 1-eicosanol, polyethylene glycol, diglycol stearate and above-mentioned material mixture, or be Na (CH according to arbitrary proportion
3COO) 3H
2O, Cd (NO
3)
24H
2O, Fe (NO
3)
26H
2O, hydration NaOH, Na
2B
4O
710H
2O, Na
3PO
412H
2O, Na
2P
2O
710H
2O and above-mentioned material are according to the mixture of arbitrary proportion.
The preparation method of composite heat-insulating layer is that wall mounts the phase-change thermal storage layer outside the tank earlier, between phase-change thermal storage layer and outer cover of water heater, adopts integral foam fabrication techniques polyurethane foam thermal insulation layer then.The integral foam technology is meant and adopts perfusion machinery, after mixing urethane raw, injects foaming in the cavity between water heater phase-change thermal storage layer and shell.Behind the foaming, shell, polyurethane foam thermal insulation layer and phase-change thermal storage layer form an integral body.
Composite heat-insulating layer among the present invention has formed the insulation mechanism of heat accumulation-heat insulation coupling; Its heat-storage heat-preserving principle is: when in actual water temperature is lower than water heater, establishing temperature; Power connection, electric heating tube begin heating, and water temperature rises rapidly; After surpassing the phase-change material fusing point, the phase-change thermal storage layer begins to be melted to whole liquid state; After water temperature surpassed the setting holding temperature, power supply broke off, and electric heating tube stops heat supply, and water temperature slowly descends, and when being lower than the phase-change material fusing point, the phase-change thermal storage layer begins to solidify emits latent heat, and it is constant to keep water temperature.Polyurethane foamed material in the heat-insulation layer then plays good heat-blocking action.Phase-change material is in high temperature (fusing point of relative material own) heat absorption down, and partial heat energy had both been recycled in heat release under the low temperature, prolonged the on/off cycle again, had reduced the energy consumption of water heater water storage insulating process.
Advantage of the present invention mainly contains: 1) compare with traditional storage-type electric water heater; Owing to adopt the novel heat insulation mechanism of heat accumulation-heat insulation coupling; Use power is low; Efficiency of utilization is high, can significantly reduce insulating process energy consumption (theoretical energy-conservation 25~45%), satisfies country-level energy efficiency indexes (GB21519-2008) requirement.2) phase-change material is selected alkane, saturated carboxylic acid and saturated alcohol ester type organic and hydrated inorganic thing, media security, nontoxic, environmental protection for use.3) the phase-change material packaging technology adopts grand capsule technique, processes the sheet capsule and closely is arranged between polyurethane foam thermal insulation layer and the water heater liner, and technology is simple, and is easy to operate, and the phase-change material consumption is few, and cost is low.4) the phase-change material external is put into, and polluted water does not influence the inner bag capacity.
Description of drawings
Fig. 1 is a kind of structural representation of phase-change thermal storage energy-saving electric water heater; Wherein, outer cover of water heater 1, heat-insulation layer 2, inner bag 3, magnesium rod 4, sewage draining exit 5, hot water outlet 6, cold water inlet 7, earth leakage circuit-breaker 8, temperature controller 9, electric heating tube 10.
Fig. 2 is the partial enlarged drawing at Figure 1A place, wherein polyurethane foam thermal insulation layer 11, phase-change thermal storage layer 12
The specific embodiment
The present invention includes outer cover of water heater 1, heat-insulation layer 2, inner bag 3, magnesium rod 4, sewage draining exit 5, hot water outlet 6, cold water inlet 7, earth leakage circuit-breaker 8, temperature controller 9, electric heating tube 10; Heat-insulation layer 2 between outer cover of water heater and the inner bag adopts the composite heat-insulating layer design; Composite heat-insulating layer is made up of polyurethane foam thermal insulation layer 11 and phase-change thermal storage layer 12; Dual insulation through heat accumulation-heat insulation coupling realizes the energy-conservation of storage-type electric water heater, and polyurethane foam thermal insulation layer 11 is between shell 1 and phase-change thermal storage layer 12, and phase-change thermal storage layer 12 is close to inner bag 3 outsides; Composite heat-insulating layer gross thickness 25~45mm, phase-change thermal storage layer 12 is 0.4~0.8 with polyurethane foam thermal insulation layer 11 thickness ratio.
Instance 1
In the storage-type electric water heater of capacity 40L (water tank internal diameter 0.336m, cylindrical shell length 0.50m), use the composite heat-insulating layer that contains phase-change material, thickness is 0.045m.Wherein phase-change material is selected positive octacosane for use, and phase transition temperature is 62.8 ℃, and enthalpy of phase change is 244J/g, and density is 0.910g/m
3, process the phase-change thermal storage layer through grand capsule technique, to be close to the inner bag outside and to insert, thickness is 0.019m.Adopt integral foam technology preparation polyurethane foam thermal insulation layer, be full of space between phase-change thermal storage layer and shell, thickness is 0.026m, and promptly the phase-change thermal storage layer is 0.73 with polyurethane foam thermal insulation layer thickness ratio.This water heater is tested according to the correlation test condition of " storage-type electric water heater efficiency limit value and efficiency grade " standard (GB21519-2008) defined; The result shows; This water heater and traditional storage-type electric water heater (use pure polyurethane foam insulation layer between shell and inner bag; Thickness 0.045m) compare, intrinsic coefficient of energy dissipation index reduced by 12.4% in its 24 hours.
Instance 2
In the storage-type electric water heater of capacity 50L (water tank internal diameter 0.336m, cylindrical shell length 0.605m), use the composite heat-insulating layer that contains phase-change material, thickness is 0.035m.Wherein phase-change material is selected the 1-hexadecanoic acid for use, and phase transition temperature is 64 ℃, and enthalpy of phase change is 200J/g, and density is 0.850g/m
3, process the phase-change thermal storage layer through grand capsule technique, to be close to the inner bag outside and to insert, thickness is 0.015m.Adopt integral foam technology preparation polyurethane foam thermal insulation layer, be full of space between phase-change thermal storage layer and shell, thickness is 0.020m, and promptly the phase-change thermal storage layer is 0.75 with polyurethane foam thermal insulation layer thickness ratio.This water heater is tested according to the correlation test condition described in the instance 1; The result shows; This water heater and traditional storage-type electric water heater (using pure polyurethane foam insulation layer, thickness 0.035m between shell and inner bag) are compared, and intrinsic coefficient of energy dissipation index had reduced by 8.3% in its 24 hours.
Instance 3
In the storage-type electric water heater of capacity 60L (water tank internal diameter 0.336m, cylindrical shell length 0.71m), use the composite heat-insulating layer that contains phase-change material, thickness is 0.035m.Wherein phase-change material is selected positive hentriacontane for use, and phase transition temperature is 65 ℃, and enthalpy of phase change is 252J/g, and density is 0.910g/m
3, process the phase-change thermal storage layer through grand capsule technique, to be close to the inner bag outside and to insert, thickness is 0.013m.Adopt integral foam technology preparation polyurethane foam thermal insulation layer, be full of space between phase-change thermal storage layer and shell, thickness is 0.022m, and promptly the phase-change thermal storage layer is 0.59 with polyurethane foam thermal insulation layer thickness ratio.This water heater is tested according to the correlation test condition described in the instance 1; The result shows; This water heater and traditional storage-type electric water heater (using pure polyurethane foam insulation layer, thickness 0.035m between shell and inner bag) are compared, and intrinsic coefficient of energy dissipation index had reduced by 9.5% in its 24 hours.
Instance 4
In the storage-type electric water heater of capacity 80L (water tank internal diameter 0.406m, cylindrical shell length 0.674m), use the composite heat-insulating layer that contains phase-change material, thickness is 0.025m.Wherein phase-change material is selected hydration NaOH for use, and phase transition temperature is 64.3 ℃, and enthalpy of phase change is 227.6J/g, and density is 1.690g/m
3, process the phase-change thermal storage layer through grand capsule technique, to be close to the inner bag outside and to insert, thickness is 0.009m.Adopt integral foam technology preparation polyurethane foam thermal insulation layer, be full of space between phase-change thermal storage layer and shell, thickness is 0.016m, and promptly the phase-change thermal storage layer is 0.56 with polyurethane foam thermal insulation layer thickness ratio.This water heater is tested according to the correlation test condition described in the instance 1; The result shows; This water heater and traditional storage-type electric water heater (using pure polyurethane foam insulation layer, thickness 0.025m between shell and inner bag) are compared, and intrinsic coefficient of energy dissipation index had reduced by 10.3% in its 24 hours.
Instance 5
In the storage-type electric water heater of capacity 100L (water tank internal diameter 0.406m, cylindrical shell length 0.824m), use the composite heat-insulating layer that contains phase-change material, thickness is 0.025m.Wherein phase-change material is selected Na (CH for use
3COO) 3H
2O, phase transition temperature is 58.4 ℃, and enthalpy of phase change is 280.0J/g, and density is 1.450g/m
3This phase-change material is processed the phase-change thermal storage layer through grand capsule technique, is close to the inner bag outside and inserts, and thickness is 0.008m.Adopt integral foam technology preparation polyurethane foam thermal insulation layer, be full of space between phase-change thermal storage layer and shell, thickness is 0.017m, and promptly the phase-change thermal storage layer is 0.47 with polyurethane foam thermal insulation layer thickness ratio.This water heater is tested according to the correlation test condition described in the instance 1; The result shows; This water heater and traditional storage-type electric water heater (using pure polyurethane foam insulation layer, thickness 0.025m between shell and inner bag) are compared, and intrinsic coefficient of energy dissipation index had reduced by 11.1% in its 24 hours.