HOT-WATER PRODUCTION SYSTEM OF HEAT PUMP TYPE Technical Field The present invention relates to a heat pump type hot water production system. More particularly, the present invention relates to a heat pump type hot water production system which can remove problems related with the rise of water temperature up to at least about 70 C as well as raise water temperature up to at least about 70C rapidly to achieve advantageous energy efficiency. The present invention can essentially remove icing such as frost occurring in pipes and other components between an evaporating heat exchanger and a compressor which has been caused by gradual temperature drop of heat exchange medium flowing through the evaporating heat exchanger when the conventional compressor 1 is actuated for a long time period to raise hot-water temperature up to at least about 70C. In addition, the present invention can omit the arrangement of an additional auxiliary heater since hot water temperature is under 70C, and thus has an advantageous energy efficiency.

Background Art An example of a conventional heat pump type hot-cold water supply system is disclosed in Laid-Open Korean Patent Application No. 2002-6429, previously filed by the assignee of this application on February 5,2002.

Such a hot-cold water supply system includes a compressor 1, a first condenser 3, an expansion valve 5 and an evaporator 7 to establish a basic cooling cycle, in which the first condenser 3 compresses input refrigerant into a gaseous state, the first condenser3 liquidizes gaseous refrigerant of a high temperature and pressure discharged from the compressor 1 into liquid refrigerant of an intermediate temperature and high pressure

with ambient air blown by a blower fan 4, and the expansion valve 5 decompresses liquid refrigerant discharged from the condenser into a low temperature and pressure state. The evaporator 7 allows liquid refrigerant of the low temperature and pressure state to absorb heat from input fluid or water so that liquid refrigerant can evaporate to transform its phase into a gaseous state.

Then, a second condenser 30 is installed in an outlet passageway of the compressor 1 to condense high temperature and pressure gaseous refrigerant discharged from the compressor 1 with fluid fed thereto as well as feed warm fluid. At the side of the second condenser, a first supply pump 21 is installed 30 to supply fluid for the condensation to the second condenser 30. At the side of the evaporator 7, a second supply pump 23 is installed to supply fluid for the evaporation to the evaporator 7.

The second condenser 30 includes first to third heat exchangers 31,33 and 35 in order to supply fluid of low, intermediate and high temperatures.

In the outlet passageway of the compressor 1, an oil separator 9 is installed to separate oil from refrigerant discharged from the compressor 1. In an inlet passageway of the compressor 1, a refrigerant heat exchanger 11 is installed to maintain the temperature and pressure of refrigerant introduced into the compressor 1 at a predetermined value in order to relieve the compressor 1 from impact which is caused by pressure difference owing to the introduction of supercooled refrigerant.

In the outlet passageway of the second condenser 3 0, a drier 13 is installed to remove impurities and moisture from refrigerant that is discharged from the second condenser 30.

Valves 15a and 15b are installed in input and output ends of

the drier 13 in order to cut off the passageway during the replacement of the drier 13.

At the output end of the drier 13, a refrigerant regulator 17 is installed to regulate the flow rate of refrigerant. A temperature sensor 19 is installed in the evaporator 7 to detect the temperature of the evaporator 7 so that the entire system can be stopped at the detection of an abnormal temperature.

Solid lines in the aforementioned drawing represent refrigerant circulation lines which connect the aforementioned components together through which refrigerant circulate.

Dotted lines represent fluid circulation lines through which fluid is circulated and converted into warm fluid and cold fluid.

Reference signs 25a, 25b and 25c represent first to third solenoid valves, respectively, which electrically open/close the refrigerant circulation lines.

However, the aforementioned prior art has following problems.

First, since the prior art is aimed to produce hot and cold water in a single system, the system cannot heat water above about 70 C.

Second, heating hot water above about 70C requires the compressor 1 to be operated for a long time. This causes poor energy efficiency while overloading the compressor 1.

Third, operating the compressor 1 for a long time to heat hot water above about 70C gradually lowers the temperature of heat exchange medium flowing through the evaporator 7. This disadvantageously causes icing in which the piping between the evaporator 7 and the compressor 1 and other components are frosted.

Fourth, since hot water has a relatively low temperature of under 70 C, a separate auxiliary heater powered by electricity is installed to rapidly raise the temperature of hot water. This

also causes poor energy efficiency to the prior art.

Fifth, input water having a temperature of 40C or more creates hot gas thereby stopping the compressor.

Brief Description of the Drawings FIG. 1 is an illustration of the prior art; and FIG. 2 is an illustration of a heat pump type hot water production system of the present invention.

<Major Reference Signs of the Drawings> 100 : compressor 200 : condensing heat exchanger 201 : heat exchange medium passageway 210 : first condensing heat exchanger 220 : second condensing heat exchanger 300 : expansion valve 400 : evaporating heat exchanger 510 : water tank 520 : recondensing heat exchanger Disclosure of the Invention Technical Object The present invention has been made to solve the foregoing problems. The present invention provides a heat pump type hot water production system which can remove problems related with the rise of water temperature up to at least about 70C as well as raise water temperature up to at least about 70C rapidly to achieve advantageous energy efficiency. The hot water production system of the present invention can essentially remove icing such as frost occurring in pipes and other components between an evaporating heat exchanger and a compressor which has been caused by gradual temperature drop of heat exchange medium flowing through the evaporating heat exchanger when the conventional compressor 1 is actuated for

a long time period to raise hot water temperature up to at least about 70 C. In addition, the hot water production system of the present invention can omit the arrangement of an additional auxiliary heater since hot water temperature is under 70C, and thus has an advantageous energy efficiency.

Technical Solution According to an aspect of the present invention for realizing the above objects, there is provided a heat pump type hot water production system. The heat pump type hot water production system of the present invention includes a compressor, a condensing heat exchanger, an expansion valve and an evaporating heat exchanger which are connected in sequence via lines through which heat exchange medium can flow, by which cold water supplied from the outside is circulated through a fluid passageway within the condensing heat exchanger arranged separate from a heat exchange medium passageway to heated through the heat exchange with heat exchange medium. The heat pump type hot water production system of the present invention further includes means for maintaining the temperature of heat exchange medium flowing through the evaporating heat exchanger at a constant range.

Advantageous Effects According to the present invention, the heat pump type hot water production system can remove the problems related with the rise of water temperature up to at least about 70C as well as raise water temperature up to at least about 70 C rapidly to achieve advantageous energy efficiency. The hot water production system of the present invention can essentially remove icing such as frost occurring in pipes and other components between an evaporating heat exchanger and a

compressor which has been caused by gradual temperature drop of heat exchange medium flowing through the evaporating heat exchanger when the conventional compressor 1 is actuated for a long time period to raise hot water temperature up to at least about 70 C. In addition, the hot water production system of the present invention can omit the arrangement of an additional auxiliary heater since hot water temperature is under 70C, and thus has an advantageous energy efficiency.

Best Mode for Carrying Out the Invention Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

FIG. 2 is an illustration of a heat pump type hot water production system of the present invention. the present invention is related to a heat pump type hot water production system which includes a compressor 100, a condensing heat exchanger 200, an expansion valve 300 and an evaporating heat exchanger 400 which are connected in sequence via lines through which heat exchange medium can flow, by which cold water supplied from the outside is circulated through a fluid passageway 202 within the condensing heat exchanger 200 arranged separate from a heat exchange medium passageway 201 to heated through the heat exchange with heat exchange medium.

In addition, means for maintaining the temperature of heat exchange medium flowing through the evaporating heat exchanger 400 at a constant range is also provided.

The temperature-maintaining means includes a fluid passageway 402 formed within the evaporating heat exchanger 400 separate from a heat exchange medium passageway 401, heat-exchanging means 500 for allowing cold water supplied from the outside to exchange heat with heat exchange medium which

has flown through the condensing heat exchanger 200 so as to be heated to at least a predetermined temperature, an inlet pipe 501 connecting an inlet side of the fluid passageway 402 with an outlet side of the heat-exchanging means 500 so that hot water of the predetermined temperature discharged from the heat-exchanging means 500 is introduced into the evaporating heat exchanger 400, a return pipe 502 for connecting an outlet side of the fluid passageway 402 with an inlet side of the heat-exchanging means 500 so that hot water of the predetermined temperature discharged from the evaporating heat exchanger 400 returns to the heat-exchanging means 500, and a pump 503 installed in the inlet pipe 501 or the return pipe 502 to forcibly circulate hot water, wherein heat exchange medium discharged from the heat-exchanging means 500 is connected with heat exchange medium passageway 401 through an inlet side of the evaporating heat exchanger 400 via a pipe 504.

The heat-exchanging means 500 includes a water tank 510 having an inlet port 510a and an outlet port 510b, the water tank 510 storing a portion of cold water supplied from the outside, a recondensing heat exchanger 520 installed within the water tank 510, and having an inlet port 500a connected with an outlet side of the condensing heat exchanger 200 via a line 222 and an outlet port 550b connected with an outlet side of the expansion valve 300 via the pipe 504, wherein the fluid passageway 402 formed separate from heat exchange medium passageway 401 has an inlet side 402a connected with an outlet port 501b of the water tank 510 via the inlet pipe 501 and an outlet side 402b connected with an inlet port 501a of the water tank 510 via the return pipe 502.

The condensing heat exchanger 200 includes a first condensing heat exchanger 210, wherein heat exchange medium discharged from the compressor 100 is diverged via a separator

110 and introduced into the first condensing heat exchanger 210, and second condensing heat exchangers 220. Heat exchange medium discharged from the first condensing heat exchanger 210 is connected to the inlet side of the evaporating heat exchanger 400, and heat exchange medium discharged from the second condensing heat exchangers 220 is connected with the inlet port 500a of the heat-exchanging means 500. In the meantime, cold water introduced into the first condensing heat exchanger 210 is diverged via a separator 250, so that a portion of cold water is pumped via a pump 251 to be discharged through the fluid passageway 202, and introduced into the fluid passageway 202 within the second condensing heat exchangers 220 such that hot water is discharged to the outside via a pipe 221, and the rest of cold water diverged via the separator 250 is introduced upstream of the water tank510.

The second condensing heat exchangers 220 are at least two heat exchangers which are connected together in parallel.

The a portion of the cold water portion introduced into the second condensing heat exchanger 220 from the first condensing heat exchanger 210 returns to the separator 250 via a pipe 241 to join cold water flowing into the first condensing heat exchanger 210.

In addition, water head detecting means 540 is provided upstream of the water tank 510 so that cold water diverged via the separator 250 is filled into the water tank 510 at a predetermined level.

The present invention having the aforementioned structure will have the following operation.

The operation of the present invention will be divided into three parts, that is, the flow of heat exchange medium, the flow of cold water and the heat exchange between heat exchange medium and cold water.

First, the flow of heat exchange medium will be described.

At the initial actuation of the hot water production system of the present invention, heat exchange medium is transformed into a gaseous state of a high temperature and pressure through the compression by the compressor 100, thereby initializing a cycle.

Oil is removed, when heat exchange medium discharged from the compressor 10 passages through an oil separator 101, and only working fluid is flown.

Heat exchange medium of the high temperature and pressure is diverged via a separator 110 into two portions, which are introduced into the first condensing heat exchanger 210 and the second condensing heat exchanger 220, respectively.

The first portion of heat exchange medium introduced into the first condensing heat exchanger 210 flows through the passageway 201 and the pipe 504, and expands through the expansion valve 300 into an easily evaporative state. Then, while passing through the heat exchange medium passageway 401 of the evaporating heat exchanger 400, this heat exchange medium portion performs heat exchange with the surrounding, converts into a gaseous state of a low temperature and pressure, and then returns to the compressor 100.

The second portion of heat exchange medium diverged via the separator 110 flows through the heat exchange medium passageway 201 of the second condensing heat exchanger 220 and passes through the recondensing heat exchanger 520 of the heat-exchanging means 500. After having passed through the recondensing heat exchanger, this heat exchange medium portion flows through a pipe 505 and into the expansion valve 300.

Hereinbefore the flow of heat exchange medium has been described.

The flow of cold water will now be described.

Cold water is introduced from a cold water supply via pumping, and diverged via a separator 250. A first portion of cold water is introduced into the first condensing heat exchanger 210, discharged to the outside of the first condensing heat exchanger 210 through the fluid passageway 220, and flows through the pipe 505 into the second condensing heat exchanger 220.

After being introduced into the heat exchanger 220, this cold water portion is discharged from the second heat exchanger 220 through the fluid passageway 202 and then to the outside through the pipe 221, during which this cold water portion passes through a hot water header 221a which temporarily stores fluid.

The first cold water portion flowing through the pipe 505 is diverged again via the separator 240 so that a portion is bypassed to the separator 250 to join cold water supplied from the cold water supply.

The rest of cold water, which is pumped from the cold water supply and diverged by the separator 250, flows through the pipe 506 and into upstream of the water tank 510.

In this case, water head detecting means 540 is provided upstream of the water tank 510 so that cold water diverged via the separator 250 is filled into the water tank 510 at a predetermined level.

After being filled into the water tank 510 to the predetermined level, cold water is discharged through the outlet port 510b via the actuation of the pump 503, flows through the inlet pipe 501 into the inlet side 402a of the evaporating heat exchanger 400, flows through the fluid passageway 402 in the evaporating heat exchanger 400, discharges through the outlet side 402b, flows through the return pipe 502, and is introduced into the water tank 510 via the inlet port 510a.

That is, cold water is continuously circulated via the pumping of the pump 503 between the water tank 510 and the

evaporating heat exchanger 400.

The flow of cold water has been described hereinbefore.

Hereinafter the process of heat exchange between cold water and heat exchange medium will be described.

First, within the first condensing heat exchanger 210, heat exchange medium of high temperature and pressure flowing through the heat exchange medium passageway 201 performs heat exchange with cold water flowing through the fluid passageway 202.

Through the heat exchange, cold water is raised in temperature for at least a predetermined value. When this water performs heat exchange with heat exchange medium of high temperature and pressure in the second condensing heat exchanger 220, hot water which is raised in temperature up to about 70C is discharged through the pipe 221.

Hot water discharged like this is used in a bath room, a boiler and so on.

In the meantime, hot water discharged from the first condensing heat exchanger 210 is diverged via the separator 240 so that a portion of hot water is bypassed into the separator 250.

Cold water, which is diverged by the separator 250 flows through the pipe 506 and filled into the water tank 510, performs heat exchange with heat exchange medium of high temperature and pressure, which is supplied into the second condensing heat exchanger 220, and converts into a hot water state of a predetermined temperature.

Also, heat exchange medium introduced into the recondensing heat exchanger 52 is condensed again.

Through the actuation of the pump 503, hot water in the water tank 510 circulates through the evaporating heat exchanger 400 and then returns to the water tank 510. In this process,

hot water performs heat exchange with heat exchange medium in the evaporating heat exchanger 400 to prevent the temperature of heat exchange medium from dropping under a predetermined value.

As a result, this can prevent drawbacks of the prior art in which icing such as frost takes place around the evaporating heat exchanger 400 and the compressor 100.

In more detail, the temperature of heat exchange medium can be maintained constant within the evaporating heat exchanger 400.

Herein the reference signs 600,610 and 620 represent a manometer, a high and low pressure cutoff switch and a high pressure cutoff switch, respectively. The reference sign 630 represents a window by which the state of heat exchange medium can be observed, the reference sign 640 represents a drier having a filter therein, and the reference sign 650 is an electronic valve for blocking the passageway.

The reference sign 660 is a liquid separator for separating liquid components from heat exchange medium.

These components of the above reference signs will not be described in detail since they are generally used in the art.

Accordingly, the present invention can prevent the conventional problem in which the compressor malfunctions owing to the creation of hot gas when cold water has an inlet temperature of at least 40C.

In addition, the conventional first condenser 3 having the blower fan 4 is not necessary, and thus fabrication cost and so on can be saved.