Hot water appliance

Abstract

A hot water appliance 10 comprises a water tank 12 provided with a water tank wall 14. The hot water appliance 10 further comprises a vacuum vessel 20 which encloses a vacuum space V. The water tank 12 is wholly included in the vacuum space, and the whole water tank wall 14 is bounded by vacuum. The vacuum vessel 20 is provided with a vacuum vessel wall 22 which consists of a number of vacuum vessel wall parts that are gastightly connected with each other by welding or soldering. Further, the hot water appliance 10 comprises at least one functional pipe 100, 200, 300, 400, 500 which extends through the water tank wall 14 and is gastightly connected with the water tank wall 14 at the location of a water tank wall connection 18. The functional pipe 100, 200, 300, 400, 500 also extends through the vacuum vessel wall 22 and is gastightly connected with the vacuum vessel wall 22 at the location of a vacuum vessel wall connection 24.

1 . A hot water appliance comprising:
 a water tank comprising a water tank wall;   a heating element included in the water tank;   a vacuum vessel enclosing a vacuum space, the water tank being wholly included in the vacuum space, the whole water tank wall being bounded by vacuum, the vacuum vessel comprising a vacuum vessel wall consisting of a number of vacuum vessel wall parts gastightly connected with each other by welding or soldering;   at least one functional pipe extending through the water tank wall and being gastightly connected with the water tank wall at the location of a water tank wall connection, and the functional pipe extending also through the vacuum vessel wall and being gastightly connected with the vacuum vessel wall at the location of a vacuum vessel wall connection.   
     
     
         2 . The hot water appliance according to  claim 1 , wherein the water tank is exclusively borne by the at least one functional pipe. 
     
     
         3 . The hot water appliance according to  claim 2 , wherein the weight of the water tank is transferred via the at least one functional pipe to the vacuum vessel wall. 
     
     
         4 . The hot water appliance according to  claim 1 , wherein a part of the at least one functional pipe that extends between the water tank wall connection and the vacuum vessel wall connection determines a heat transport length l h  for heat conduction from the water tank wall connection to the vacuum vessel wall connection and has a wall sectional area A, where a ratio between heat transport length l h  in mm and wall sectional area A in mm 2  satisfies the formula l h /A>4 mm −1 . 
     
     
         5 . The hot water appliance according to  claim 1 , wherein the part of the at least one functional pipe that extends between the water tank wall connection and the vacuum vessel wall connection has a heat transport length l h  that is greater than 60 mm, wherein the material of the at least one functional pipe is one of stainless steel, titanium or Incoloy, respectively. 
     
     
         6 . The hot water appliance according to  claim 1 , wherein the at least one functional pipe has an external diameter that is less than 8 mm. 
     
     
         7 . The hot water appliance according to  claim 1 , wherein the at least one functional pipe has a wall thickness that is between 0.4 and 1.0 mm. 
     
     
         8 . The hot water appliance according to  claim 1 , wherein water tank wall connection and the vacuum vessel wall connection are welded joints. 
     
     
         9 . The hot water appliance according to  claim 1 , wherein water tank wall connection and the vacuum vessel wall connection are soldered joints. 
     
     
         10 . The hot water appliance according to  claim 1 , wherein the at least one functional pipe comprises at least one of a water supply pipe, a water discharge pipe, an electric heating element containing pipe, and a temperature sensor containing pipe. 
     
     
         11 . The hot water appliance according to  claim 1 , wherein the water tank comprises a cylindrical water tank sidewall and wherein the vacuum vessel comprises a cylindrical vacuum vessel sidewall, wherein at least between the cylindrical water tank sidewall and the cylindrical vacuum vessel sidewall, a laminate of reflecting foil and glass fiber cloth is included. 
     
     
         12 . The hot water appliance according to  claim 11 , wherein the laminate comprises at least three layers of reflecting foil and at least three layers of glass fiber cloth. 
     
     
         13 . The hot water appliance according to  claim 1 , wherein the at least one functional pipe comprises a first pipe part, a first bend which connects the first pipe part with a second pipe part, a second bend which connects the second pipe part with a third pipe part;
 wherein the first pipe part extends through an upper side of the vacuum vessel;   wherein the third pipe part extends through a bottom side of the water tank;   wherein the first pipe part extends substantially vertically between the water tank wall and the vacuum vessel wall.   
     
     
         14 . The hot water appliance according to  claim 13 , wherein the at least one functional pipe comprises:
 a first functional pipe which is a water supply pipe that extends through and is gastightly connected with a first vacuum top wall opening and which extends through and is gastightly connected with a first water tank bottom wall opening;   a second functional pipe which is a water discharge pipe which extends through and is gastightly connected with a second vacuum top wall opening and which extends through and is gastightly connected with a second water tank bottom wall opening;   a third functional pipe which is a first heating element pipe part which extends through and is gastightly connected with a third vacuum top wall opening and which extends through and is gastightly connected with a third water tank bottom wall opening;   a fourth functional pipe which is a second heating element pipe part which extends through and is gastightly connected with a fourth vacuum top wall opening and which extends through and is gastightly connected with a fourth water tank bottom wall opening, wherein the third functional pipe and the fourth functional pipe are mutually connected via a spiral pipe part, wherein the third functional pipe, the fourth functional pipe and the spiral pipe part form an integral one-piece part in which a heating element and cabling to that heating element are included; and   a fifth functional pipe which is a sensor pipe which extends through and is gastightly connected with a fifth vacuum top wall opening and which extends through and is gastightly connected with a fifth water tank bottom wall opening, wherein in the sensor pipe at least a temperature sensor and cabling to that temperature sensor are included.   
     
     
         15 . The hot water appliance according to  claim 14 , wherein the water tank and the vacuum vessel each have a cylindrical configuration, wherein the first, second, third, fourth and fifth vacuum vessel top wall openings each have a center which is located on a common pitch circle whose diameter is greater than an outer diameter of the cylindrical water tank and less than the inner diameter of the cylindrical vacuum vessel and whose center is located on a vertical axis of the cylindrical vacuum vessel. 
     
     
         16 . The hot water appliance according to  claim 14 , wherein the first, the second, the third, the fourth and the fifth water tank bottom wall openings each have a center located in a common vertical plane. 
     
     
         17 . The hot water appliance according to  claim 13 , wherein between the first pipe part of the at least one functional pipe and the vacuum vessel wall a first spacer is included which is manufactured from a material having a heat conductivity coefficient that is less than 5 W/(m·K). 
     
     
         18 . The hot water appliance according to  claim 13 , wherein the at least first pipe part exclusively abuts against the water tank wall at a transition between a water tank bottom side and a water tank sidewall. 
     
     
         19 . The hot water appliance according to  claim 17 , wherein a transition of a water tank upper side and the water tank sidewall and an upper part of the at least first pipe part are located at a distance from each other. 
     
     
         20 . The hot water appliance according to  claim 19 , wherein the upper part of the at least first pipe part and the water tank upper side are fixed with respect to each other with the aid of a fixing element. 
     
     
         21 . The hot water appliance according to  claim 20 , wherein the fixing element is implemented as a second spacer which keeps the water tank adjacent a transition of a water tank upper side and the water tank sidewall on the one hand, and an upper part of the first pipe part of the at least one functional pipe on the other, at a distance from each other, and which engages, on the one hand, the water tank and, on the other, the upper part of the first pipe part of the at least one functional pipe. 
     
     
         22 . The hot water appliance according to  claim 21 , wherein the second spacer's engagement of the water tank is realized on the upper side of the water tank at the location of the axis of the water tank and wherein the spacer's engagement of the upper part of the first pipe part of the at least one functional pipe is realized on one upper part or on two upper parts.