Liquid heating
Technical field
The present invention relates to a kind of liquid heating, especially one kind to be mainly used for that water is heated to be less than steam-like temperature
Liquid heating.
Background technology
Generally, it is needing continuously to go out in the heating electrical appliance of hot water, the package by insulating layer or filling by heating resistance wire,
It is embedded in the preferable cast aluminium of thermal coefficient, while stainless steel tube bending is formed into continuous flow channel for liquids, is embedded in cast aluminium.
Because heating resistor generate heat cannot directly and water progress heat exchange, need that cast aluminium is first heated to a constant temperature
It spends, the heat on cast aluminium passes through stainless steel tube flow channel for liquids and aquatic products heat exchanges.Since the thermal inertia of aluminium is big, can exist following
Problem:1, it in booting, needs to wait for longer time 15 to 30S(Second)Cast aluminium could be heated to the temperature needed by preheating;
If 2, in the case where continuously going out hot water, the heat that heating resistance wire generates cannot keep up with the heat of liquid absorption, meeting in time
The temperature of cast aluminium is caused to decline, water temperature if necessary cannot decline, and need to continue waiting for heating;If 3, heater is in and waits for
In machine, need to cause the waste of the energy with control come the temperature of constant cast aluminium;4, the cast aluminium heating with this high thermal inertia
Device, it is necessary to obtain the water of steady temperature by preheating, in continuous effluent, water temperature cannot be constant.Because of the inertia of high heat,
It can not realize that the consecutive variations of water temperature are adjusted.The production technology of cast aluminium is complicated simultaneously, and volume is big, weight weight.
Based on above problem, there are some schemes to go to improve, such as do plastic liquid runner in stainless steel thick film pipe, comes
Avoid the influence of thermal inertia, plastics that there is certain hardness, need to be inserted in stainless steel outer tube, can easily be inserted in stainless steel
In pipe, dimensional fits need to reduce the outer diameter of plastic liquid runner, can not achieve tight fit.There is no problem for installation, but can band
The problem of sealing, cause the water cannot to be flowed fully according to the flow direction of flow channel for liquids, some total water can be from being not tight seal
Gap at take a shortcut, water stream channel is certain, inevitably results in a part of water and does not flow, becomes stagnant water, continuous heating at this,
Gasification is eventually led to, steam is generated and sprays, water outlet is intermittent, simultaneously as the intermetallic sealing of plastic casing can only rely on sealing
Circle sealing can not achieve the requirement of storage pressure 8 to 10bar, in normal pressure, it is also possible to because rate or sealing ring are in the environment of high temperature
It is used for a long time and aging occurs, the risk of leakage occur.
Invention content
It is an object of the invention to overcome above-mentioned the shortcomings of the prior art, and offer is a kind of simple and reasonable for structure, adds
The liquid heating that thermal response speed is fast, low energy consumption.
The object of the present invention is achieved like this:
A kind of liquid heating, including it is cylindrical in shape the main body and heater element of structure respectively, heater element is sleeved on main body
Outside surface, heater element is made of outer tube with the heating circuit for being printed on outer tube outer surface, which is characterized in that the main body is by interior
Pipe and silica gel sheath are constituted, and inner tube both ends are sealed with outer tube both ends respectively to be coordinated, and inner cavity, silica gel sheath set are formed between outer tube and inner tube
It is located at outside inner tube and in closing inner chamber, silica gel sheath outer surface is equipped with fin, and fin coordinates with outer tube wall sealing, wherein silica gel
Set outer surface, fin and outer tube wall surround fluid flow path jointly, and main body corresponds to fluid flow path and is equipped with feed pathway
And liquid outlet channel.
The purpose of the present invention can also use following technical measures to solve:
As a more specific scheme, the outer tube and inner tube are stainless pipe, inner tube both ends respectively with outer tube two
End is sealed by welding manner.
Said inner tube both ends are respectively equipped with flanging, flanging and outer tube port sealing.In order to realize storage pressure, in main body two
Outward flanging is held, then after being inserted in heater element, main body and heater element are formed into sealing structure with the mode of welding, ensured<
The storage pressure energy power of 50Bar.Welding can reliably realize that sealing, liquid will not be revealed.
The silica gel sheath both ends are respectively equipped with the rib that turns up, and silica gel sheath is tightly placed in outside inner tube, turn up rib and inner tube it is outer
Flange is closely fitted.The silica gel sheath can be tightly placed in by way of cast outside inner tube, avoid hot body enter silica gel sheath with
Between interior pipe surface, its efficiency of heating surface is reduced.
The fin spiral is arranged in silica gel sheath periphery, is surrounded jointly helically with silica gel sheath outer surface and outer tube wall
The fluid flow path of shape, feed pathway and the next upper arrangement of liquid outlet channel one are connected to fluid flow path both ends respectively.Spiral shell
The fluid flow path of rotation shape defines liquid helical flow, so as to do sufficient heat exchange with heater element.For liquid
The contact area of the heat exchange of body and heater element realization large area, body element and heater element wants sufficiently small, ensures fever
The heat that element generates passes to liquid in time, so using sealing fin(Raised corner angle can fill up between auxiliary element
Gap, ensure liquid regularly flowed along flow channel for liquids)Reduce contact area.It can also allow on heating resistor and be led simultaneously
The temperature of volume elements part covering part will not be excessively high, beneficial to main body heater element.In order to which liquid flowing is smooth, need spiral helicine
There is fluid flow path certain linear velocity and angular speed, the i.e. arrangement in fluid passage road to need certain angle of inclination, no
As for forming resistance on fluid passage.Because proportion declines after heated liquid, hot liquid can always flow up.
As more preferably scheme, the wall thickness of the outer tube and inner tube is respectively 0.5mm to 1mm.
The main body of such liquid heating is made of inner tube and silica gel sheath, and thermal inertia is less than metal or the heat of plastics is used
Amount, while the residual water in channel is 5 to 8ml.Heating element have silk-screen on the surface apparent surface of main body
Adding thermal resistance.The steel pipe thickness of main body is 0.5mm, if the specification according to 2000W calculates, length 62mm, outer diameter is
The specific heat of 43mm, silica gel weight 16.5g, silica gel are 0.27J/(g.℃)If 25 DEG C of main body is heated to 85 DEG C, heating
The heat of absorption is:0.27J/(g.℃)*16.5g*(85-25)℃≈267J.Heating time needs: 267J/2000W≈
0.1S individually considers the thermal inertia of main body, it is only necessary to which 2s can 65 DEG C of temperature liter.
Residual water in heating tube is 6ml, if being heated to 85 DEG C from 25 DEG C, the heat of absorption is:4.2 J/(g.℃)*
6g*(85-25)℃≈1512J.Heating time needs:1512J/2000W ≈ 0.7S need main body and remaining water temperature rising 60
DEG C time only need the S of 0.7+0.1=0.8.
Simultaneously as the insulating materials of thickness only 83um between adding thermal resistance and stainless steel outer tube or so, and with it is good
Good lateral thermal conductivity coefficient stainless steel is combined together, thus assists the thermal inertia of heater element also very little, reduces heat stream
It loses.In this way, since this silk-screen type heater element can be evenly heated in the large surface towards liquid, so improving fever member
The total thermal conductivity efficiency of part.
Liquid is quickly and almost all receives the heat passed over from silk-screen resistance, and then liquid can add in a flash
Heat.So when device does not work, do not need to provide a large amount of energy to make it keep enough high temperature, heating at this moment
The energy expenditure of device is zero.
The heating circuit includes the insulating bottom layer, heating resistor and insulating outer layer that print burns in outer tube outer wall successively, insulation
The heating energization input with heating resistor conductive contact is additionally provided on bottom.Heating resistor face liquid communication as far as possible
Path so that the heat that heating resistor generates is flowed through the liquid absorption of fluid flow path as possible.Meanwhile the rail of heating resistor
Mark is between the liquid level that liquid in-out channel is formed, i.e., the liquid level that liquid in-out channel is formed includes the track of heating resistor, it is ensured that work
When making, the heat that heating resistor generates transmits liquid in time, is unlikely to burn heating resistor because of overheat.
The heating resistor is at least sintered by one layer of resistance slurry, is equipped with a plurality of, each heating resistor from top to bottom
It is mutually parallel, is connected by conductive access bridge between adjacent two heating resistors, the heating resistor of upper and lower ends is supplied with heating respectively
Electrical input is conductively connected.
It is additionally provided with temperature controlling device on the insulating bottom layer of the heating circuit.
The temperature controlling device includes temperature control temperature sensing device and/or anti-dry temperature sensing device, is additionally provided on heating circuit
The temperature acquisition electrode being electrically connected with temperature controlling device;Wherein, temperature control is positioned close at liquid outlet channel and is use up with temperature sensing device
Amount is far from heating resistor;Anti-dry is located at temperature sensing device by heating resistor.Since the purpose of temperature control temperature sensing device is mainly
It detects liquid temperature and feeds back to control circuit, control circuit is set out with user needed for liquid according to liquid temperature data is surveyed out
Temperature is compared, and automatically adjusts the power of heating resistor, realizes accurate temperature control.Therefore, temperature control temperature sensing device close proximity to
Liquid outlet channel can obtain the liquid temperature closest to liquid outlet channel, but simultaneously again far from heating resistor, in order to avoid by heating resistor shadow
Ring its data measured, i.e., temperature control have left the path of the heating resistor of face in liquid with temperature sensing device after, before outlet
Face liquid position.When heating resistor heats liquid in fluid flow path, with liquid heat occurs for heating resistor
It exchanges, so temperature declines, but if lack liquid, there is over-temperature condition quickly in the Wen Sheng of heating resistor, so, prevent dry
Burning needs the position for being positioned close to heating resistor with temperature sensing device.
Beneficial effects of the present invention are as follows:
(1)Such liquid heating can reduce the booting preheating stand-by period at 3 seconds or so, and continuous effluent temperature is stablized,
When standby, heating is needed not rely on to maintain the temperature of cast aluminium;
(2)Such liquid heating is avoided that the gap because between flow channel for liquids and stainless steel thick film heater, band
The string water problems come causes to gasify, and that brings goes out water vapour and discontinuous water outlet;
(3)Such liquid heating seals inner and outer tubes by the way of welding, can bear storage pressure<50bar
Requirement, avoid be used for a long time leakage;
(4)Such liquid heating is simple in structure, and manufacturing cost is cheap;
(5)Such liquid heating can generate rapidly water of the temperature between 60 DEG C to 98 DEG C, while storage being needed to press<
50bar is applicable to electric coffee maker, espresso maker and beverage heater etc., meets to coffee or beverage mouthfeel and nutrition
Extraction;
(6)Such liquid heating can obtain the water of continuous-stable temperature or transformation temperature in initial and any time.
Description of the drawings
Fig. 1 is one embodiment of the invention decomposition texture schematic diagram.
Fig. 2 is structural schematic diagram after Fig. 1 assembly.
Fig. 3 is present invention looks up structural representation of the present invention.
Fig. 4 is the A-A schematic cross-sectional views of Fig. 3.
Specific implementation mode
The invention will be further described with reference to the accompanying drawings and embodiments:
Shown in Fig. 1 to Fig. 4, a kind of liquid heating, including it is cylindrical in shape the main body 20 and fever member of structure respectively
Part 10, heater element 10 are sleeved on outside 20 surface of main body, and heater element 10 is by outer tube 1 and the heating electric for being printed on 1 outer surface of outer tube
Road is constituted, and the main body 20 is made of inner tube 6 and silica gel sheath 5, and 6 both ends of inner tube are sealed with 1 both ends of outer tube respectively to be coordinated, outer tube 1
Inner cavity is formed between inner tube 6, silica gel sheath 5 is set in outside inner tube 6 and in closing inner chamber, and 5 outer surface of silica gel sheath is equipped with fin
52, fin 52 coordinates with 1 inner wall sealing of outer tube, wherein 5 outer surface of silica gel sheath, fin 52 and 1 inner wall of outer tube surround liquid jointly
Circulation path 7, main body 20 correspond to fluid flow path 7 and are equipped with feed pathway 63 and liquid outlet channel 62.
The outer tube 1 and inner tube 6 are stainless pipe, and 6 both ends of inner tube are close by welding manner with 1 both ends of outer tube respectively
Envelope.
The outer tube 1 and the wall thickness of inner tube 6 are respectively 0.5mm to 1mm.
6 both ends of said inner tube are respectively equipped with flanging 64, flanging 64 and 1 port sealing of outer tube.
5 both ends of the silica gel sheath are respectively equipped with the rib 54 that turns up, and silica gel sheath 5 is tightly placed in outside inner tube 6, turn up rib 54 with it is interior
The flanging 64 of pipe 6 is closely fitted.
52 spiral of the fin is arranged in 5 periphery of silica gel sheath, is surrounded jointly with 5 outer surface of silica gel sheath and 1 inner wall of outer tube
Spiral fluid flow path 7, feed pathway 63 and liquid outlet channel 62 1 it is next it is upper arrangement, respectively with fluid flow path
7 both ends are connected to.The inside of inner tube 6 forms cavity 61, be equipped in cavity 61 inlet tube 66 and outlet tube 65 respectively with feed pathway 63
It is connected to liquid outlet channel 62.
The heating circuit includes the insulating bottom layer 2, heating resistor 3 and insulating outer layer that print burns in 1 outer wall of outer tube successively, absolutely
The heating energization input 32 with 3 conductive contact of heating resistor is additionally provided on edge bottom 2.
The heating resistor 3 is at least sintered by one layer of resistance slurry, is equipped with a plurality of, each heating resistor from top to bottom
3 are mutually parallel, and are connected by conductive access bridge 31 between adjacent two heating resistors 3, the heating resistors 3 of upper and lower ends respectively with add
Hot energization input 32 is conductively connected.
It is additionally provided with temperature controlling device on the insulating bottom layer 2 of the heating circuit.
The temperature controlling device includes temperature control temperature sensing device 41 and anti-dry temperature sensing device 42, is additionally provided on heating circuit
The temperature acquisition electrode 43 being electrically connected with temperature controlling device;Wherein, temperature control temperature sensing device 41 is positioned close to liquid outlet channel 62
Locate and as possible far from heating resistor 3;Anti-dry is located at temperature sensing device 42 by heating resistor 3.
In above-described embodiment:Liquid heating by one 6 outer surface of stainless steel inner tube pour into a mould silica gel main body 20, with
And a heater element 10 being arranged outside the main body is constituted, heater element 10 burns the stainless steel outer tube for having heating circuit by surface print
1 is constituted, 10 both ends welded seal of main body 20 and heater element, the fin 52 of binding silica gel set 5 so that main body 20 and heater element
The fluid flow path 7 that spiral shape rises is formed between 10, inlet tube 66 of the water along lower section, which enters in fluid flow path 7, does spiral shell
Shape ascending motion is revolved, for water in flow process, the heat that heater element 10 generates passes to the inner surface and flowing water reality of outer tube
It is flowed out from outlet tube 65 after existing heat exchange.
Since inner tube 6 is using 0.5 to 1.0mm stainless steel tube, a cavity 61 is formed in pipe, reduces the matter of stainless steel
Amount reduces thermal inertia.The ability to bear for considering pressure-resistant 50bar simultaneously, in order to which 1 both ends of same outer tube realize that there are one annulus after welding
Cavity structure, by inner tube both ends outward flanging 64.The cast thickness of above-mentioned silica gel sheath 5 is 0.8mm, fin 52(Helix is convex
The corner angle risen)Height is 2mm, and the pitch of fin 52 is 10.5mm, i.e. the depth of fluid flow path 7 is much smaller than width, liquid
When fluid flow path 7 flows, large area absorbs the heat that heater element 10 is transmitted via the inner surface of outer tube 1.In general, outer
The shape that high lateral thermal conductance and low thermal inertia is all made in pipe 1 needs the thickness that most probable is small to rapidly realize lateral heat transfer
Degree, but in order to bear the pressure of 50bar, in this example, using the thickness stainless steel of 0.8mm.The principle of the selection of material,
Silk-screen heating circuit can be passed through on its surface.
The silk-screen of heating circuit:It is printed in stainless steel outer pipe surface and burns one layer of insulating dielectric materials(Insulating bottom layer), according to need
It wants that insulation pressure resistance can be improved by three layers or four layers insulation, print burns electrode material, realizes electrical connection, and then print burns heating electric
Resistance, on the surface of heating resistor, print burns one or more layers insulating protective layer(Insulating outer layer).The power of heater element generally exists
1200 to 2800W, maximum power range is determined according to water flow and leaving water temperature.
Because the entire channel of fluid flow path 7 is not the track of a straight line, while being subtracted according to the heated rear density of water
Principle small, that hot water flows up, cannot rely on the flowing of gravitational force urges water, because of the requirement for having storage to press, need a storage pressure
Water pump push water flowing.
Temperature control temperature sensing device 41 is integrated on heating circuit outside outer tube 1(NTC temperature sensing devices), temperature control temperature sensing device
41 perceive the temperature of liquid in fluid flow path 7 by the thickness of insulating bottom layer 2 and outer tube 1, accurate in order to ensure to measure
Property and constantly property.Temperature control temperature sensing device 41 is arranged in the position slightly remote from heating resistor, avoids the temperature of heating resistor to control
The temperature interference of temperature sensing device 41.
Anti-dry temperature sensing device 42 is integrated on outer tube 1(Another NTC temperature sensing devices), prevent in anhydrous dry combustion method or fever
When the inner surface fouling of resistance face, by dry combustion method or incrustation scale assembly situation, distance are able to detect that within the shortest time
Close to heating resistor, specific location needs are determined according to the time of dry combustion method or threshold temperature.
Temperature control at work, is measured the temperature of liquid in fluid flow path 7, returns to PCB controls with temperature sensing device 41,
By calculating the power of regulation heating resistance 3, control leaving water temperature reaches required value.
When occurring largely adhering to incrustation scale on anhydrous dry combustion method or 1 inner surface of heating resistor face outer tube, produced on heater element
Raw heat cannot laterally be taken away, and temperature steeply rises, and laterally deliver heat to anti-dry temperature sensing device 42, when arrival setting
When threshold temperature, automaticallys cut off the power and overheating protection is realized to heater element.
When just starting to start, to ensure that leaving water temperature is desired temperature, temperature control is measured first with temperature sensing device 41
The temperature of liquid in fluid flow path 7 calculates preheating conduction time according to Current Temperatures and leaving water temperature, is arrived when preheating time
After reaching, pump working shortens the time that equalized temperature is established to reduce the temperature oscillation period, ought for the previous period in root
Determine that a constant power, the boundary condition of calculating include according to calculating:Inflow temperature, leaving water temperature, flow, operating voltage,
The rated power etc. of device.After the completion of this time, the temperature returned by measurement controls to adjust the power of heater element,
Closed-loop control is formed, until after heating time or water yield reach, is stopped.
In control technology, other than the power of control heating resistor 2, the flow of control water pump can also be selected.Preheating
After time reaches, determine that a constant flow, the boundary condition of calculating include according to calculating when interior for the previous period:Into water temperature
The rated power etc. of degree, leaving water temperature, flow, operating voltage, device.After the completion of this time, by measuring the temperature returned
Degree controls to adjust the flow of water pump, forms closed-loop control, until after heating time or water yield reach, is stopped.
This device actually is being used, according to calculating and multiple actual test, when just starting to start, maximum duration exists
85 DEG C of hot water can be gone out in 3S, temperature stablizes settling time in 3S, and temperature is stablized in +/- 2 DEG C.When preheating in 3S
Between be very short, constant holding temperature need not be always maintained at when standby, avoided because of the standby energy waste brought.
It is to sum up told, the device according to the invention has many advantages, in particular, it has very small thermal inertia.Thus,
When powering to heater element, the process very short time can go out hot water.
The structure of water channel is only the channel of an opposing seal, will not cause to generate steam because of string water or flow continues absolutely
It is continuous, safe risk, continuous effluent will not be brought to bring the stable mood experience of user because of the ejection of steam.
In the structure of water stream channel, all-welded sealing means have been used, the storage pressure of maximum 50bar can be born, it is full
The extraction of sufficient coffee or beverage mouthfeel and nutrition.It avoids because of the leakage problem that other sealing structures are brought.
NTC temperature sensors are by the way of integrated and the heat exchange of water is seamless structure, in NTC temperature sensing
For the entire surface of device by very thin insulating layer and stainless steel measuring temperature, thermal response time is short, temperature control 41 thermometric of temperature sensing device
Promptly and accurately, the control of accurate temperature is realized, anti-dry temperature sensing device 42 detects sensitive, is reliably achieved overheating protection, nothing
Additional mounting structure is needed, it is at low cost.