KR20030071607A - Heat pump system of cooling, heating and hot water using binary refrigerating machine with two stage cascade refrigeration - Google Patents

Abstract

PURPOSE: A heat pump system is provided to reduce manufacturing costs and energy consumption, while achieving improved efficiency. CONSTITUTION: A heat pump system comprises a high temperature side compressor(HC) for compressing, into a high temperature high pressure state, the high temperature side gas refrigerant evaporated from a cascade condenser(E3) serving as an evaporator of a high temperature side refrigerating cycle and a condenser of a low temperature side refrigerating cycle; a high temperature side condenser(E1) for condensing the refrigerant gas compressed into the high temperature high pressure state by the high temperature side compressor; a high temperature side supercooler(E2) where the refrigerant cooled by the high temperature side condenser is heat exchanged and supercooled; a high temperature side expansion valve(V1) which performs a throttling operation such that the supercooled refrigerant is easily evaporated; a low temperature side compressor(LC) for compressing the refrigerant gas evaporated from an evaporator and accumulator(E4) into a high temperature high pressure refrigerant gas; and a low temperature side expansion valve(V2) which performs a throttling operation such that the refrigerant condensed by the cascade condenser is easily evaporated.

Description

Heat pump system of cooling, heating and hot water using binary refrigerating machine with two stage cascade refrigeration}

The present invention relates to an ultra-low power heat pump that uses a midnight electric power in a late night time zone with low electric power demand to configure a dual refrigeration cycle to simultaneously perform heating and cooling during the year and hot water supply.

In general, energy-saving technologies related to air conditioning and heating, which are generally used in Korea, include electric drive pumps (EHPs), gas engine drive heat pumps (GHPs), ice storage systems, and late-night electric heat storage boilers. First, the electric drive pump may be described using a general refrigeration cycle as an example. The refrigeration cycle consists of a compressor, a condenser, an expansion valve, and an evaporator to absorb heat from the outside while the refrigerant boils in the evaporator, and the boiled refrigerant gas is compressed into a gas of high temperature and high pressure in the compressor and sent to the condenser. By releasing the refrigerant, the high-pressure refrigerant gas is condensed, leading to a low-temperature, high-pressure liquid state. As the refrigerant condensed as described above is throttled and expanded through an expansion valve, some refrigerant liquid evaporates, and through absorption of the latent heat, the refrigerant liquid becomes an abnormal state in which a liquid phase of cold and low pressure and a gaseous phase coexist together. Boil through the evaporator. In this way, the refrigeration cycle has a part for absorbing heat and a part for discharging at the same time, it can be seen as a pump that absorbs heat from the evaporator to arrange it in the condenser, that is, transfer heat. An apparatus for transferring heat as described above is called a heat pump, and air conditioning is regarded as an apparatus for simultaneously cooling and heating.

The electric drive heat pump is configured to simultaneously cool and heat a single compressor cycle, that is, a single-stage cycle. As shown in Table 1 below, when the outside air temperature is -5 ° C or lower, the evaporation temperature is lowered to reduce the refrigerant mass flow rate. The heating output is severely lacking, and the efficiency is insufficient for winter heating. The heat pump receives energy driving the compressor from the outside and transfers heat from a low heat source to a high heat source and is used to make the refrigerant gas at a high temperature and high pressure. This heat pump is generally different from an electric heater that converts electrical energy into thermal energy. Will occur. In the case of an electric heater, the electric energy is simply converted into thermal energy, but the heat pump converts the refrigerant into input energy while compressing the refrigerant into input energy, and the compressed refrigerant transfers its energy to transfer heat in the process of making the reactive energy effective. By converting, the efficiency can be expected to be 3 to 4 times higher than that of an electric heater. At this time, when the external input energy is input into electricity, it becomes an electric drive heat pump, and when driven by an engine that burns gas and obtains an output, it is a gas engine drive heat pump. When cooling is required, the refrigerant is compressed and condensed in the outdoor unit and evaporated and absorbed in the indoor unit. When heating, the evaporated and compressed in the outdoor unit and the condensation arrangement in the indoor unit enables heating and cooling with one heat pump. At the time of heating, it is possible to operate more efficiently than the boiler or electric heater because of the characteristics of the heat pump described above, and can be spotlighted as an energy saving device. However, cooling and heating cycles are formed differently. When cooling, condensation temperature is 45 ℃ ~ 50 ℃ and evaporation temperature is about 5 ℃. When heating, condensation temperature is 35 ℃ ~ 40 ℃ and evaporation temperature is -10 ℃ ~ -20 lower than winter outdoor temperature. It is formed at ℃. As described above, various problems occur in the heating operation than in the cooling operation. The lowering of the evaporation temperature means that the saturation pressure of the refrigerant is lowered, and when the saturation pressure is lowered, the refrigerant mass flow rate decreases, which means that the refrigerant is capable of heating. Is to decrease. Due to such technical difficulties, the conventional electric heat pump has solved a lack of heat during heating by providing an auxiliary heater, but the advantages of the heat pump are inevitably reduced. The gas engine driving heat pump overcomes these disadvantages, and the gas engine driving system has a similar point of cooling and heating by using a compressor as a gas engine. However, when heating, insufficient heat source is recovered by supplying the waste heat arranged in the gas engine, and thus the heating capacity can be avoided due to the decrease in the outside air temperature in winter, and the remaining energy can be used in summer by burning the gas without using electric energy. As gas is supplied at a moderate price (1/2 level), users can obtain energy sources at low prices, and the market is largely established in Korea, and the prospect is bright. . However, since the efficiency of the gas engine, which is the core of the gas engine driving system, is still low and the coefficient of performance is known to be around 1.2, it is a problem that a lot of gas is consumed and most of the gas engine driven heat pumps are imported from Japan. There are problems leading to foreign currency outflow. Also recently₂ Nitrogen oxide (NOx), which is generated and environmental pollutants are generated, has problems with environmental pollution. The supply and demand of electric power supplies is not good in today's public air conditioners, and new power plants need to be built in response to peak loads during peak summer hours due to increased air conditioners. Has a very high cost and becomes very economically national as long as it can be leveled off the rest of the time by avoiding peak loads.

Fuganan for this purpose is the ice heat storage and the late-night electric heat storage boiler which heat and cool by using the late-night time zone.

In the case of ice heat storage, the ice is frozen during the late-night hours (22: 00 ~ 08: 00) to cover the cooling load during the day. In Korea, installation of refrigeration cooling systems is mandatory depending on the size and use of the building. The late night cold storage includes both ice storage and heat of shrinkage, and the heat of shrinkage produces cold water at night time without freezing the ice. The evaporation temperature of the freezer is higher than that of ice storage. Therefore, the capacity of the heat storage tank is 6 times larger than that of the ice storage heat, and in fact, the ice storage heat storage system in Korea, which has a narrow territory, is more widely supplied. Like the heat storage, the late night electric heat storage boiler heats up during the night time to perform hot water supply and heating necessary during the day.

The ice heat storage and shrinkage system, which is a late night heat storage, can be used only for cooling in the summer. For heating, the boiler must be installed as a separate heating facility, and the late night electric heat storage boiler is 1/3 ~ 1/4 more efficient than a general heat pump. Low, there is a disadvantage in that a separate air conditioning in summer. It is equipped with a heat pump system as an ice storage freezer (low temperature freezer) to manufacture hot water in the middle of the night, but it can be used only in buildings that generate waste heat due to operating conditions. However, since the temperature of hot water is around 45 ℃, a separate boiler facility must be provided to meet the required temperature of hot water, 60 ℃ ~ 70 ℃. In addition, in order to maintain the temperature of hot water at 60 ℃ ~ 70 ℃, R-134A which has lower saturation pressure than refrigerants such as R-22, R-407C and R-404A, which are currently commercial refrigerants, can be considered. As the appropriate refrigeration capacity is sharply reduced, it can be unreasonable, accompanied by a rise in compressor cost and a decrease in the performance coefficient due to high compression ratio operation.

Therefore, the present invention can simultaneously produce the cold heat source and the heat source, which is the greatest advantage of the heat pump, and take advantage of the use of inexpensive late night power, which is the advantage of the heat storage and heat storage type, and decrease the heating output during winter, which is a disadvantage of the electric heat pump. The high cost of gas engine heat pump, the problem of foreign currency outflow, the lack of heat source which is a disadvantage of ice storage heat storage type, the lack of cold source which is a disadvantage of electric boiler heat storage type, and the ability to overcome all the problems of low efficiency In order to overcome the expected decrease in efficiency, the purpose of the present invention is to maintain the advantages of the existing heating and cooling system, to overcome the disadvantages, and to provide a more efficient technology.

Table 1 below summarizes the principles, advantages, and disadvantages of the technologies that have been conventionally used for heating and cooling.

principle Advantages Disadvantages Electric Heat Pump (EHP) -.Heat pump is driven by electricity to cool the room using evaporator in summer, and condensation in winter. -. It has the advantage of heating and cooling with one device. Seasonal power supply and demand can be balanced by using surplus power during the winter season. -. As the evaporation temperature decreases due to the decrease of the outdoor air temperature in winter, the heating output is insufficient due to the decrease of the refrigerant mass flow rate. In case of supplying air as air, it is limited to the southern part of Korea, and if water is used, it can be supplied only to buildings that generate waste heat. Gas Heat Pump (GHP) -. It is similar to electric heat pump, but uses gas which is cheaper than electricity by using gas driving engine without electricity. By using the engine array for insufficient heat supply when heating, the capacity is prevented from being lowered due to the decrease in the outside air temperature during winter, which is a disadvantage of EHP. -. By using gas in summer, it is possible to reduce power load concentrated in summer, so the operation cost is low by applying gas rate discounted in summer. There is no deterioration of capacity due to the decrease of the outside air temperature by using the engine array during the winter season. -. The price is very expensive since the gas engine must be separately. Low system grade factor-. Carbon dioxide and NOx environmental pollutants are generated. As most of the products are imported from Japan, foreign currency outflow is high. Ice storage system -. Considering the peak load of electric power during summer cooling, ice-making is performed at night to melt ice during the day. There are various methods such as ice slurry, outer icing type and ice ball type. -. It is possible to reduce the pig load concentrated during the summer day, so it receives a late night surcharge, so the operation cost is low. -. Since only cooling is possible, there must be a separate boiler for heating and hot water supply, and the boiler operation time is long. Ice heat storage heat pump -. It is a system that recovers waste heat to a freezer that performs general ice storage to hot water storage. -. In addition to the advantages of ice heat storage, hot water heat storage is performed at the same time. -. In the case of waste heat recovery when hot water is regenerated, the effect is large and the temperature of hot water is low, so it must be reheated through a boiler. Electric heat storage boiler -. It is a system that accumulates hot water by converting electrical energy into thermal energy using a nighttime electricity that is devoted to value. -. Use low-cost late night electricity. -. The efficiency is very low because it merely converts electrical energy into thermal energy.

An object of the present invention is to introduce a dual cooling cycle in order to solve the problems and disadvantages as described above to utilize the cooling and heating and hot water supply in ultra-low power.

Two-way refrigeration cycle has two separate refrigeration cycles. The low-temperature cycle that handles the evaporator to obtain the low temperature and the condensation in the low-temperature freezer are not condensed with air or water like the normal refrigeration equipment. It is to liquefy. Binary refrigeration cycle has been mainly used in ultra low temperature device (-50 ℃ ~ -80 ℃), in order to obtain ultra low temperature, the refrigerant applied to the low temperature cycle cycle has been mainly used ultra high pressure refrigerant that can not condense at room temperature.

In order to operate at a high efficiency in a cycle having a large difference between the condensation temperature and the evaporation temperature, which is the core of the technical problem solution of the present invention, a dual refrigeration cycle was introduced.

The present invention constitutes a high temperature side refrigeration cycle using a low pressure refrigerant capable of realizing a high condensation temperature at the time of heat storage, and requires a low evaporation temperature at the time of heat storage, and thus a low temperature using a high pressure refrigerant capable of stable operation even at a low evaporation temperature. It is characterized by constituting the side refrigeration cycle, this cycle configuration can obtain a stable condensation pressure, in the case of the low temperature side of the actual refrigeration capacity by using a high-pressure refrigerant to reduce the discharge amount of the compressor, The compression ratio can be reduced to have a high grade coefficient, and a heat pump that simultaneously stores and stores heat can be operated with high efficiency.

While maintaining the advantages of existing heat pumps and heat storage systems, it is possible to overcome the disadvantages of each device.

Table 2 shows the superiority of the present invention by comparing the heat pump cycle calculation results of applying the refrigerant with different refrigerants and the calculation results of the two-way refrigeration cycle in the conventional single stage compression heat pump.

Comparison of refrigeration cycles for heat storage and heat storage by cycle method Cycle method Single stage compression Binary refrigeration cycle High temperature side Cold side Used refrigerant R134A R-22 R-407C R134A R410A Condensation temperature (℃) 75 Evaporation Temperature (℃) -15 Supercooling degree 5 'K 5 'K 0'K Compressor Discharge Rate (㎥ / hr) 100 100 100 16.2 16.2 Condensation Pressure (kg / ㎠) 24.11 33.83 38.58 24.11 19.16 Evaporation pressure (kg / ㎠) 1.67 3.02 2.68 7.15 4.89 Ice storage capacity (kcal / hr) 9,208 11,895 14,598 9,875 Heat storage capacity (kcal / hr) 19,737 22,247 27,730 16,581 Used power (kw) 12.24 12.04 15.27 7.85 Cooling performance coefficient 0.87 1.15 1.11 1.46 Heating performance coefficient 1.87 2.15 2.11 2.45 Overall performance coefficient 2.74 3.30 3.22 3.92

The following conditions are the legend obtained from Table 2 above.

1. Refrigerant properties were used with NIST's REFPROP 7.0, which provides a high level of calculated values.

2. In the cycle analysis, it is assumed that the mass of refrigerant for each element is the same. (Law of mass conservation)

3. The volumetric efficiency and compression efficiency applied to the compressor were calculated by inverting the refrigerating capacity and axial force of the semi-hermetic compressor catalog produced in Germany and applied to the function through regression analysis.

4. During binary refrigeration cycle analysis, assuming that the low temperature side condensation load and the high temperature side evaporation load are the same (the law of energy conservation), the high temperature side evaporation temperature and the high temperature side evaporation load and the low temperature side condensation load are the same. The simulation was carried out in such a way that the cold side condensation temperature was determined.

As shown in Table 2 above, it can be seen that various problems appear when using the single-stage compression cycle to simultaneously implement the cooling and the heat storage. When the R134A is used to configure the heat pump system with the single-stage compression cycle, the compression ratio becomes very large. As a result, it can be seen that the compressor volume efficiency is lowered, the compression efficiency is lowered, and very large axial force is required. In addition, when the remaining refrigerant groups (R-22, R-407C) were used, the condensation pressure was over 30 bar, so it was impossible to operate. Therefore, R-134A is possible under the operating conditions for producing cold storage and hot water at 70 ℃, but it is very inefficient. There is a number. However, compared to the single stage compression method, the present inventors of the present invention may increase the manufacturing cost because the cycle consists of two types, but the discharge amount of the compressor can be reduced by about 70% compared to the single stage compression (when R-134A is applied). As can be seen from the overall performance factor, energy savings of over 30% are possible.

In addition, in order to maintain the temperature of hot water at 60 ℃ ~ 70 ℃, R-134A, which has lower saturation pressure than refrigerants such as R-22, R-407C, R-404A, which are currently commercial refrigerants, can be considered. As the appropriate refrigeration capacity is sharply reduced, it can be unreasonable, accompanied by a rise in compressor cost and a decrease in coefficient of performance due to non-compression operation.

The binary refrigeration cycle heat pump for heat storage of the ice shaft and high temperature hot water to be achieved in the present invention can be applied as follows.

In summer, ice storage and hot water operation simultaneously operate the low temperature side refrigeration cycle and the high temperature side refrigeration cycle to perform ice storage operation in the evaporator of the low temperature side refrigeration cycle, and to accumulate heat in the condenser of the high temperature side refrigeration cycle for hot water storage for ice storage and hot water supply. Therefore, the ice storage heat storage is similar to the existing ice storage heat storage method, but there is an advantage of not using a boiler for producing hot water. When manufacturing hot water with a heat pump, the production cost of hot water is greatly reduced compared to when the boiler is operated. Will have an effect.

After the summer hot water heat storage is completed as described above, the operation mode is to stop the high-temperature side refrigeration cycle and drive only the low-temperature side refrigeration cycle has the advantage that it can be operated as a single-stage compression cycle and a binary refrigeration cycle according to the operating conditions. During the mid-term (spring and autumn), heating, cooling, and hot water supply occur simultaneously in each time zone, so you can use as many heat sources as you want during the day by simultaneously performing ice storage and heat storage operation at night. In winter, in buildings where waste heat is generated in the low-temperature side evaporator and ice storage tank (E4), heat is recovered from the waste heat source, and in the absence of the waste heat source, the heat is absorbed from the low-temperature side air-cooled evaporator (E4_1). At (E1), the high temperature heat is stored in the late night time zone to supply the heat source for heating and hot water supply during the day. In buildings where heating loads and hot water loads occur at the same time, it is necessary to heat storage in the late-night time zone and to manufacture as many heat sources as necessary during the day time zone. In buildings with no waste heat, heat sources can be produced by absorbing heat from outside air.

1 is a schematic diagram of a heat pump using a binary refrigeration cycle capable of simultaneously performing ice storage and heat storage according to the present invention.

<Description of Symbols for Main Parts of Drawings>

HC: high temperature side compressor LC: low temperature side compressor

R1: Hot water storage tank E1: High temperature side condenser

E2: high temperature side supercooler E3: cascade condenser

E3_1: Low temperature side air cooled condenser E4: Evaporator and ice condenser

E5: Waste Heat Recovery Heat Exchanger

E4_1: Low temperature side air cooled evaporator V1: High temperature side expansion valve

V2: Low temperature side expansion valve V1_1: High temperature side expansion valve

V2_1: Low Temperature Side Expansion Valve Brief Description

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings in order to achieve the object as described above.

1 is a schematic diagram of a heat pump using a binary refrigeration cycle capable of simultaneously performing ice storage and heat storage according to the present invention.

First, the cold storage and the heat storage at the same time in the summer night time zone is used for air conditioning for daytime cooling. The heat stored in the heat storage tank is hot water of 70 ℃ or higher and can be used for other purposes such as showering. Two-way refrigeration cycle is formed by two separate refrigeration cycles, and the low temperature side refrigeration cycle for the evaporator to obtain the low temperature and the condensation of refrigerant in the low temperature side refrigeration unit are not performed by air or cooling water, as in the case of a general single stage refrigeration unit. Condensate into a high temperature side refrigeration cycle.

First, the high temperature side refrigeration cycle of a dual refrigeration cycle heat pump will be used for hot water supply and heating as a cycle for heat storage through summer and winter heat storage tanks, and with reference to Fig. 1, it will be an evaporator of a high temperature side refrigeration cycle. High-temperature side compressor (HC) for compressing the refrigerant in the high-temperature gas state evaporated in the cascade condenser (E3) corresponding to the condenser of the low-temperature side refrigeration cycle at high temperature and high pressure, the refrigerant compressed at high temperature and high pressure in the high temperature side compressor (HC) The high temperature side condenser E1 for condensing the gas by flowing coolant, the medium temperature refrigerant liquid cooled in the high temperature side condenser E1 is first heat-exchanged, and the high temperature side supercooler E2 and the high temperature side where the refrigerant liquid is supercooled. While expanding in the high temperature side expansion valve (V1), the high temperature side expansion valve (V1) throttling so that the supercooled refrigerant liquid through the subcooler (E2) can easily evaporate Some of the high-temperature side refrigerant is evaporated and the refrigerant changed to an abnormal state of low-temperature low-pressure (liquid gas phase coexists) flows back into the cascade condenser (E3) to evaporate while condensing the high-temperature high-pressure refrigerant gas at the low temperature side. The gas flows back into the high temperature side compressor (HC) and repeats the cycle of being compressed into the gas of high temperature and high pressure.

Described the late-night heat storage process of hot water as hot water and heating water, the time water (cooling water) introduced into the hot side supercooler (E2) is subjected to the first heat exchange with the condensed refrigerant liquid discharged from the high temperature side condenser (E1). The preheated water is exchanged with the refrigerant gas of high temperature and high pressure again in the high temperature side condenser (E1) to become high temperature water and stored in the hot water heat storage tank (R1).

On the other hand, when describing the low-temperature side refrigeration cycle of the two-way refrigeration cycle heat pump, in the present invention, when there is no waste heat source for ice storage and winter heating and hot water supply through the cold storage tank for cooling in winter, As a cycle for securing a heat source, referring to FIG. 1, a low-temperature compressor (LC) for compressing refrigerant gas evaporated in an evaporator and an ice storage tank (E4) into a refrigerant gas of high temperature and high pressure in the summer ice storage, and the low temperature side The high temperature and high pressure refrigerant gas compressed by the compressor LC is throttled so that the refrigerant liquid condensed in the cascade condenser E3 corresponding to the evaporator of the high temperature side refrigeration cycle and the condenser of the low temperature side refrigeration cycle can easily evaporate. When the low temperature side expansion valve (V2), the low temperature side expansion valve (V2) is expanded while some of the low temperature side refrigerant liquid evaporates, the low temperature low pressure abnormal state (liquid The refrigerant changed into a gaseous state) flows into the evaporator and the ice storage tank (E4) and continues to ice during the late night hours, and the evaporated refrigerant gas flows back into the low temperature side compressor (LC) and is compressed into a gas of high temperature and high pressure. The cycle will repeat.

In more detail, the ice cooling process of summer cooling is characterized in that the two-way refrigeration cycle heat pump is operated at the same time as the above described high temperature side refrigeration cycle and low temperature side refrigeration cycle. When no more heat storage is available in R1), that is, when the hot water heat storage is completed before the ice storage tank in the late-night hours, the high temperature side refrigeration cycle is stopped immediately and only the low temperature side refrigeration cycle is operated. Due to the stop of the high temperature side refrigeration cycle, the high temperature and high pressure refrigerant gas compressed by the low temperature side compressor (LC) does not flow to the cascade condenser E3, but is bypassed to the low temperature side air cooling condenser E3_1 so that the refrigerant liquid Is condensed, and the condensed refrigerant expands in the low temperature side expansion valve (V2) while some low temperature side refrigerant liquid evaporates, thereby causing an abnormal phase of low temperature and low pressure. The refrigerant changed to (liquid gas phase coexists) flows into the evaporator and the ice storage tank (E4) and continues to ice in the late night hours, and the evaporated refrigerant gas flows back into the low temperature side compressor (LC) to be a gas of high temperature and high pressure. The cycle of compression is repeated.

On the other hand, if there is detailed description about heating and hot water supply when there is waste heat source in winter and when there is no waste heat source,

First, when there is no waste heat source capable of recovering heat, the winter hot water supply and heating operation closes the low temperature side expansion valve (V2) for the low temperature side evaporator and ice storage tank (E4), and opens the low temperature side expansion valve (V2_1). When the refrigerant flows into the low temperature side air-cooled evaporator (E4_1), absorbs heat from the outdoor air in winter, and releases the heat obtained in the cascade condenser (E3), the high temperature side refrigeration cycle is operated as described above, and the high temperature side supercooler (E2) is operated. ) The time water (cooling water) introduced into the heat exchanger is subjected to the first heat exchange with the condensed refrigerant liquid discharged from the high temperature side condenser (E1), and the preheated time water is heat exchanged with the high temperature and high pressure refrigerant gas again in the high temperature side condenser (E1). It is stored in hot water heat storage tank (R1) and is used for hot water for daytime.

Second, if there is a waste heat source that can recover heat, winter hot water supply and heating operation can be implemented in two forms, one of which passes the waste water through the evaporator and ice tank (E4) of the low-temperature side refrigeration cycle described above When the heat source is secured and the heat acquired to the cascade condenser E3 is released, the high temperature side refrigeration cycle is operated as described above, so that the time water (cooling water) introduced into the high temperature side and the cooler E2 is the high temperature side condenser E1. The first heat exchange with the condensed refrigerant liquid discharged from the), and the pre-heated time water is exchanged with the refrigerant gas of high temperature and high pressure again in the high temperature side condenser (E1) to become hot water and stored in the hot water storage tank (R1). The rest is stopped in the low temperature side refrigeration cycle, and the refrigerant liquid condensed in the high temperature side condenser E1 of the high temperature side refrigeration cycle does not pass through the cascade condenser E3. The waste heat recovery heat exchanger (E5) capable of heat exchange with the waste heat of Fig. Can be used for heating and hot water by recovering heat.

The present invention can be used in the cold district by solving the problem of reducing the heating output, which is a disadvantage of the electric driven pump, but can be used in cold districts. Reducing the manufacturing cost, and applying the present invention only to the heat storage system, the energy saving effect is more than three times higher than the existing electric heat storage boiler to provide the technology that can maintain the advantages of the existing heat pump, heat storage, heat storage system and overcome the disadvantages (See Table 3)

In addition, the present invention can be manufactured at the same time the cold heat source, the heat source of the maximum advantages of the heat pump, utilizing the advantage of the low-cost late-night power that is the advantage of the cold storage, heat storage type, reducing the heating output during the winter season, which is a disadvantage of the electric heat pump, The high cost of gas engine heat pump, the problem of foreign currency outflow, the lack of heat source which is a disadvantage of ice storage heat storage type, the lack of cold source which is a disadvantage of electric boiler heat storage type, and the ability to overcome all the problems of low efficiency In order to overcome the expected decrease in efficiency, the purpose of the present invention is to maintain the advantages of the existing heating and cooling system, to overcome the disadvantages, and to provide a more efficient technology.

The following conditions are legends to create Table 3

1.Summer season: Cold load 10,000 kcal / hr, Heat load 5,000 kcal / hr

Heating and hot water load during winter: 16,800 kcal / hr

2. During summer (3 months), cooling and hot water supply are done at the same time.

3. During the winter season (5 months), heating and hot water supply are performed at the same time.

4. Fuel costs are as follows (as of May 2003).

-. coal fuel

-Boiler: 720 won / ℓ

-City gas (heating): 480 won / ㎥, (cooling): 240 won / ㎥

-. Electricity bill

-Electricity fee (basic fee): 5,360 won / kw,

-Electricity fee: Summer 94.90 won / kwh, Spring 63.20 won / kwh, Winter 67.20 won / kwh

-Overnight electricity fee: Winter 29.8 won / kwh, Winter: 26.9 won / kwh

5. Appliances that can only produce cold heat sources were considered to be used in parallel with the equipment for manufacturing the heat source. On the contrary, appliances that could only produce heat sources were considered to be used in parallel with the equipment for manufacturing the heat source.

=> During summer cooling and hot water production Item Heat source Boiler (City gas) Boiler (City gas) Boiler (City gas) Midnight electricity Boiler New type Heat pump Cold heat source GHP Air conditioner use Ice storage Ice storage Heat source Produce Calorific value 10,500kcal / Nm³ 10,500kcal / Nm³ 10,500kcal / Nm³ 860 kcal / kw 860 kcal / kw efficiency(%) 95 95 95 95 260 Actual calorific value (kcal / h) 9,975 9,975 9,975 817 2,236 Heat load (kcal / h) 16,800 16,800 16,800 16,800 16,800 Fuel consumption 1.68Nm³ 1.68Nm³ 1.68Nm³ 20.6kw / h 7.5kw / h Electricity base Unit fuel cost 240 won / Nm³ 480 won / Nm³ 480 won / Nm³ 26.9 won / kw 26.9 won / kw Unit cost (KRW) 404 808 808 553 202 Cold heat source Produce Calorific Value (kcal / kw) 10,500 860 860 860 860 efficiency(%) 95 350 300 300 160 Actual calorific value (kcal / h) 9,975 3,010 2,580 2,580 1,376 Calories required (kcal / h) 10,000 10,000 10,000 10,000 10,000 Electric Power Fund (KRW) 59 Fuel consumption 1.00 Nm³ 3.3kw / h 3.9kw / h 3.9kw / h 0 kw / h Unit fuel cost 240 won / Nm³ 94.9won / kw 26.9 won / kw 26.9 won / kw 26.9 won / kw Unit cost (KRW) 241 375 104 104 0 Remarks Total Required Amount (KRW) 645 1,183 913 657 202 => When manufacturing winter heat source Item Heat source Boiler (City gas) Boiler (Via) GHP (Gas Heat Pump) Midnight electricity Boiler New type Heat pump Calorific value 10,500kcal / Nm³ 10,300kcal / kg 10,500kcal / Nm³ 860 kcal / kw 860 kcal / kw efficiency(%) 95 95 130 95 260 Actual calorific value (kcal / h) 9,975 9,785 13,650 817 2,236 Heat load (kcal / h) 16,800 16,800 16,800 16,800 16,800 Fuel consumption 1.68Nm³ 1.72ℓ / h 1.23Nm³ 20.6kw / h 7.5kw / h Electricity base Unit fuel cost 480 won / Nm³ 720 won / ℓ 480 won / Nm³ 26.9 won / kw 26.9 won / kw Unit cost (KRW) 808 1,236 591 553 202

1. In the heat pump system, a cold heat source can be manufactured in a low temperature side evaporator and a hot heat source can be manufactured in a high temperature side condenser. Thus, a single heat pump can provide a cooling and heating hot water supply system.

2. It is possible to make ice making operation with low evaporation temperature at low temperature evaporator and high condensation temperature at high temperature condenser to provide hot water heat storage operation, and provides technology for heat storage system utilizing midnight electric power considering power supply balance.

3. In case of heat pump, Carno cycle is used, so the coefficient of performance decreases when the temperature difference between evaporation temperature and condensation temperature increases. In systems that maintain these high temperature differentials, binary refrigeration cycles are more efficient than single stage compression. In addition, since the coolant liquid from the high temperature side condenser is high temperature, it is preheated again to produce hot water through the supercooler, so that the total refrigerating capacity is greatly increased, thereby enabling a more efficient operation.

4. As it is a two-way refrigeration cycle, the refrigerant circuit is composed of two types. At first glance, the manufacturing cost may be increased. However, since the high-pressure refrigerant is used at the low temperature side, only a small compressor is used since the refrigeration capacity per refrigerant flow rate becomes very large. Even in the single stage compression method, the total discharge amount of the compressor is smaller when the system is binary than the discharge amount of the compressor, so the overall price increase is not so high.

5. The biggest disadvantage of the electric heat pump is that the heat is supplied from the outside air. This technology provides a technique to overcome the shortcomings of the lack of condensation calories because the evaporation temperature for the summer ice storage and the evaporation temperature corresponding to the winter outside temperature is similar.

Claims (1)

In the electric drive heat pump system which performs cooling and hot water supply in summer, and heating and hot water supply in winter as a unit, the outdoor unit of the electric drive heat pump system is divided into a high temperature side refrigeration cycle and a low temperature side refrigeration cycle, which are binary refrigeration cycles. The high temperature side compressor (HC), which compresses the refrigerant in a high temperature side gas state evaporated in the cascade condenser E3 corresponding to the evaporator of the high temperature side refrigeration cycle and the condenser of the low temperature side refrigeration cycle, at high temperature and high pressure, the high temperature side compressor ( High temperature side condenser (E1) for condensing the refrigerant gas compressed to high temperature and high pressure in HC) and the medium temperature refrigerant liquid cooled in the high temperature side condenser (E1) are first heat-exchanged and the high temperature side where the refrigerant liquid is supercooled. High temperature side that is throttled so that the supercooled refrigerant liquid can easily evaporate through the subcooler E2 and the high temperature side supercooler E2. As it expands from the window valve V1 and the high temperature side expansion valve V1, it flows into the cascade condenser E3 and evaporates while condensing the low temperature high temperature high pressure refrigerant gas, and the evaporated refrigerant gas is transferred to the high temperature side compressor HC. While repeating the cycle of flowing back into the high-pressure and high-pressure gas, the time water (cooling water) introduced into the hot side supercooler (E2) undergoes a first heat exchange with the condensed refrigerant liquid discharged from the high temperature side condenser (E1). , The preheated water is exchanged with the refrigerant gas of high temperature and high pressure again in the high temperature side condenser (E1) to become high temperature water and stored in the hot water heat storage tank (R1). When there is no waste heat source for ice storage and winter heating and hot water supply through cold storage tank for cooling, it is a cycle to secure the heat source for heating and hot water supply in cold outside air in winter. In this case, the low temperature side compressor LC compresses the refrigerant gas evaporated in the evaporator and the ice storage tank E4 into the high temperature high pressure refrigerant gas, and the high temperature high pressure refrigerant gas compressed in the low temperature side compressor LC is used in the high temperature side refrigeration cycle. In the low temperature side expansion valve (V2), the low temperature side expansion valve (V2) is throttled so that the refrigerant liquid condensed in the cascade condenser (E3), which is an evaporator and a condenser of the low temperature side refrigeration cycle, can easily evaporate. As it expands, some of the low-temperature refrigerant evaporates and the refrigerant flows into the evaporator and ice storage tank (E4) to continue to ice during the late-night hours, and the evaporated refrigerant gas flows back into the low-temperature compressor (LC) to provide high temperature and high pressure. The system repeats cycles compressed with gas, and when the hot water storage tank R1 can no longer be regenerated due to the expected decrease in hot water consumption in summer, that is, during the late-night hours, the hot water heat storage is performed before the ice storage tank. When the high temperature side refrigeration cycle is stopped immediately, only the low temperature side refrigeration cycle operates. The refrigerant condensation of the low temperature side refrigeration cycle is the high temperature and high pressure refrigerant gas compressed by the low temperature side compressor (LC) due to the stop of the high temperature side refrigeration cycle. Does not flow to the cascade condenser (E3), but bypasses the low-temperature side air-cooled condenser (E3_1) to condense the refrigerant liquid, and the condensed refrigerant expands in the low-temperature expansion valve (V2) to evaporator and ice. The ice cream flows into the building E4 and continues to ice during the late night hours, and the evaporated refrigerant gas flows back into the low temperature side compressor (LC) to be compressed into a gas of high temperature and high pressure, and there is a waste heat source in winter and a waste heat source. If there is no waste heat source capable of recovering heat in the heating and hot water supply, if there is no waste heat source, the winter hot water supply and heating operation closes the low temperature side expansion valve (V2) for the low temperature side evaporator and ice storage tank (E4), Expansion valve V2_1) is opened and the refrigerant is introduced into the low temperature side air-cooled evaporator (E4_1) to absorb heat from the outside air in winter and release the heat obtained in the cascade condenser (E3), and then flows into the high temperature side and the cooler (E2) of the high temperature side refrigeration cycle. The time water (cooling water) undergoes a first heat exchange with the condensed refrigerant liquid discharged from the high temperature side condenser (E1), and the preheated time water exchanges heat with the high temperature and high pressure refrigerant gas again in the high temperature side condenser (E1) to become hot water. When there is a waste heat source stored in (R1) and recovering heat, winter hot water supply and heating operation can be implemented in two types, one of which is the evaporator and ice tank of the low temperature side refrigeration cycle described above (E4). The wastewater is passed through the wastewater, and the heat source is secured to release the heat obtained in the cascade condenser E3.The high temperature side refrigeration cycle is operated, and the time water (cooling water) flowing into the high temperature side and the cooler (E2) is the high temperature side condenser (E). First heat exchange with the condensed refrigerant liquid discharged from 1), the preheated time water is exchanged with the refrigerant gas of high temperature and high pressure again in the high temperature side condenser (E1) to become hot water and stored in the hot water storage tank (R1) for hot water use. Waste heat recovery heat exchanger which is utilized, and stops the low temperature side refrigeration cycle, and allows the refrigerant liquid condensed in the high temperature side condenser (E1) of the high temperature side refrigeration cycle to exchange heat with separate waste heat without passing through the cascade condenser (E3). Heat pump system characterized by the dual refrigeration cycle that the outdoor unit, which recovers heat through E5) and is used for cooling, heating and hot water supply, has a cascade heat exchanger.