JPH0550667B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention is a cooling/heating machine capable of cooling operation, heating operation, and cooling/heating operation.

[Conventional technology]

General-purpose air source heat pumps have extremely low efficiency during summer cooling operation because heat must be dissipated from the air heat exchanger, which has poor heat transfer. Furthermore, during heating operation in winter, heat must be collected from an air heat exchanger with poor heat transfer, and the efficiency is extremely low because the operation is performed at a low refrigerant evaporation temperature. Moreover, when the outside temperature is low during heat collection in winter, frost and ice buildup on the heat transfer surface impedes heat transfer, causing many problems such as reduced capacity and interruption of heating during the defrost cycle. ing.

[Structure of the invention]

The present invention is a cooling/heating machine that combines a refrigerator and a heat pump, and includes a first compressor A, a second compressor B, a first evaporator C, a second evaporator D, and a first condenser E. It is equipped with a second condenser F, and in cooling operation, it is combined in the order of first evaporator C → (second evaporator D) → first compressor A → first condenser E → first evaporator C. It constitutes a cooling cycle, and in heating operation, the second evaporator D → the first compressor A → the first condenser E →
2nd compressor B → 2nd condenser F (1st condenser E) →
(First evaporator C) → second evaporator D can be combined in the order to configure a heating cycle, and
This cooling/heating machine is configured to operate with high efficiency according to three different operating specifications, and is configured to perform a combination of the above-mentioned cooling operation and heating operation during cooling/heating operation, as shown in Fig. 1. It consists of a special cooling and heating system equipped with a heating tower and a cooling tower. During cooling operation, the cooling tower is activated to perform the same cooling operation as a dedicated cooling unit, enabling highly efficient operation. Furthermore, during heating operation, a heating tower can be used to perform heat pump cycle operation in the same manner as in the case of a heat pump, so it is possible to eliminate the drawbacks during heating operation.

In the example shown in Fig. 1, the cooling tower and heating tower are provided separately, but one tower with a larger capacity (usually the heating tower) is provided and used separately for the first condenser E and the second condenser. Piping may be provided to both of the evaporators D, respectively.

In addition, in the above operation mode, the second evaporator D during the cooling operation and the first condenser E and the first evaporator C during the heating operation are ones through which the refrigerant simply passes, and the refrigerant does not condense into the evaporator or condenser. I put it in parentheses because it does not function as a vessel.

The present invention has been made with the aim of improving the low efficiency of heat source devices generally manufactured as air source heat pumps in both summer and winter.

In other words, during normal cooling operation, the refrigerant is heated to 5°C.
The refrigerant is evaporated at a temperature of about -14°C, and the heat is pumped up and condensed at 38°C by suction and compression by a compressor, so the temperature difference between them is 33°C. However, during heating operation, the refrigerant evaporates at a temperature of, for example, -14°C. Since it condenses at 51℃, the temperature difference during this time is 55℃. In other words, there will be a large difference in the height at which heat is pumped up during cooling operation and heating operation, and if a single compressor is used for both purposes, cooling operation will deviate significantly from the design point, resulting in lower efficiency. They will be forced to drive at a low level.

Therefore, in the present invention, ideal high-efficiency operation can be performed with only the cooling compressor A during cooling operation, and after compressing with the cooling compressor A during heating,
The shortfall is made to bear on compressor B so that both compressors can be operated with ideal high efficiency, and two evaporators and two condensers are also provided and these are skillfully arranged.

Next, the present invention will be explained in detail based on the drawings.

In Figure 1, symbol A is the first compressor (main compressor), B is the second compressor (booster compressor), C is the first evaporator, D is the second evaporator, and E is the first condenser. ,
F is the second condenser, 1 is the cooling tower, 2 is the heating tower, 8 is the cushion tank,
20 indicates a cold cooling medium pipe from the cooling tower 1 to the first condenser, 21 indicates a heating medium pipe from the heating tower 2 to the second evaporator, and 9 and 2
0 indicates a pump on each pipe. Furthermore, 11 is a cold water pipe having a cold water flow valve 31, 17 is a hot water pipe having a hot water flow valve 32, 12 is a refrigerant vapor (refrigerant gas) pipe having a flow rate control device 5, 13 and 14 are refrigerant gas pipes, 3 is a refrigerant gas pipe having a valve 4 for closing the gas flow of the second compressor; 15 and 16 are refrigerant gas pipes; 18 is a condensed refrigerant pipe having a pressure reducing valve 33; and 19 is a condensing pipe having a pressure reducing valve 34. Refrigerant piping, 22 is a refrigerant liquid shutoff valve 35 and a flow rate adjustment valve 3
6 shows a condensed refrigerant piping with 6.

During the cooling operation of the present invention, the valve 4 that closes the gas flow to the second compressor and the hot water flow valve 32 are closed, the pump 9 is turned on, the pump 10 is turned off, and only the cooling tower is operated. Evaporator C
The refrigerant vapor evaporated in This is a simple refrigeration cycle in which the water is condensed and then refluxed to the first evaporator C. This is the same operation cycle as a standard cooling-only machine, allowing highly efficient operation. During this time, cold water is drawn out from the cold water pipe of the first evaporator C.

Next, the heating operation of the apparatus of the present invention, that is, the operating state in winter, will be explained. During heating operation, the cold water flow valve 31 on the cold water pipe is closed;
The valve 4 that closes the gas flow to the second compressor and the hot water flow valve 31 on the hot water pipe are opened, the pump 10 on the heating medium pipe is turned on, and the pump 9 on the cooling medium pipe is turned off. The refrigerant is evaporated in the second evaporator D by the heating medium from the heating tower 2, compressed by the first compressor A, and then discharged to the first condenser E. In this case, the condenser E acts simply as a passage section for the refrigerant gas. The refrigerant vapor from the condenser E is compressed by the second compressor B via the cushion tank 8, and then discharged to the hot water condenser (second condenser F), where the refrigerant is condensed and inside the condenser. Heat the water with. The condensed refrigerant is once passed through the first condenser E, passed through the first evaporator C, and then refluxed to the second evaporator D in order to have an economizer effect. In this case, the first evaporator C only acts as a passage section for the condensed refrigerant.

The cushion tank 8 is connected to a first condenser E to a second condenser.
This is provided to separate droplets when the gas sucked into compressor B contains droplets.
It can also be omitted.

Next, we will explain the operating conditions during combined heating and cooling operation (such as heating the north side of the building and cooling the south side of the building, heating the office and cooling the computer room, etc.). The hot water flow valve 32 and the refrigerant liquid stopper 35 are opened, the pumps 9 and 10 are turned on, and a part of the refrigerant is evaporated in the first evaporator C, and then the heating tower is heated in the second evaporator D. The remaining refrigerant guided through the pipe 22 is evaporated by the heating medium from the refrigerant 2, compressed by the first compressor A, and then discharged to the first condenser E. A part of the refrigerant is condensed in this first condenser E by the cooling water from the cooling tower 1, and this condensed refrigerant is led to the first evaporator C together with the condensed refrigerant from the second condenser F.
On the other hand, the refrigerant vapor in the first condenser E is compressed by the compressor B via the cushion tank 8, and then discharged to the hot water condenser (second condenser F). Heat the water inside.
The condensed refrigerant is once passed through the condenser E, then the first evaporator C, and then refluxed to the second evaporator D in order to have an economizer effect as in the heating operation.

During this time, cold water is drawn out from the cold water pipe 11 and hot water is drawn out from the hot water pipe 17.

In addition, in FIG. 1, a hot gas pipe 7 is provided from the first condenser E to the second evaporator D.
This is an aid for safe driving.

The heating tower is a heat collector from air that does not form frost or ice, and heat is collected by the second evaporator D as a heat pump via the circulating antifreeze.

During the cooling/heating operation of the present invention, the first evaporator C
When flowing a fluid that may freeze, such as water, into the cold water piping, the first evaporator C is used to prevent freezing.
A device 5 for restricting the flow rate of the refrigerant is provided on the refrigerant vapor pipe from the evaporator C to the first compressor A, and the pressure (temperature) in the first evaporator C is controlled so as not to fall below a specified value.

In addition, in heat pump operation, the second evaporator D
In order to control the pressure or temperature of the first compressor A to a constant value, a pressure or temperature detector (PCA) is provided, and the output of the first compressor A is controlled based on the pressure or temperature detected by the detector. It is preferable to control the pressure or temperature of the second evaporator D to a constant value.

In addition, when the outside temperature is high and the heat collection conditions are good,
The pressure of the second evaporator D (for example, the set pressure of PCA) (temperature) is determined by the temperature detected by the outside air temperature detector.
It is also possible to control the vapor pressure (temperature) of the second evaporator D by cascading controllers to increase the vapor pressure (temperature) of the second evaporator D.

Further, when producing hot water, if the heat requirement (demand) for hot water is small, it is preferable to adjust the capacity of the second compressor B and reduce the amount of circulating refrigerant to reduce the required power. In this case, when the refrigerant pressure in the first condenser E increases in accordance with the adjustment of the second compressor B, the pressure (temperature ) The set value of the controller is increased in cascade, the pressure (temperature) of the second evaporator D is increased to the specified value, and further, when the pressure of the first condenser E is increased, the first condensation is performed as a second stage. It is preferable to control the heat dissipation by passing cooling water through the vessel E.

By performing each of the above-described controls, energy-saving operation can be performed in many operating modes, such as when there is a load on the first evaporator C, when the hot water load is small, or when the outside air temperature is high.

FIG. 2 is a Mollier diagram showing the refrigerant cycle in the heat pump system of the present invention, where the solid line indicates the cycle of C→(D)→A→E→C, and the chain line indicates the cycle of D→A→ This shows the case of the cycle E→B→F→(E)→(C)→D. Items in parentheses such as (D), (E), and (C) do not necessarily mean that the refrigerant is flowing inside the equipment. This indicates that it is not necessary to pass through.

Although a cushion tank 8 is shown in FIG. 1, this cushion tank is not necessarily required.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing the flow of the cooling/heating machine of the present invention, and FIG. 2 is a Mollier diagram of the refrigeration cycle in the system of the present invention. A...First compressor, B...Second compressor, C...
First evaporator, D... second evaporator, E... first condenser, F... second condenser, 1... cooling tower, 2... heating tower.

Claims (1)

[Scope of Claims] 1. In a cooling/heating machine that combines a refrigerator and a heat pump, a first compressor A, a second compressor B, and a first evaporator are connected to a cold water pipe provided with a cold water flow valve 31. C, the second through the heating medium pipe 21 with the pump 10 from the heating tower 2;
an evaporator D, a first condenser E through a cooling medium pipe 20 with a pump 9 from the cooling tower 1, a cushion tank 8, a second condenser F with a hot water flow valve 32; The first evaporator C and the second evaporator D are connected by a refrigerant pipe 12, and the second evaporator D and the gas suction side of the first compressor A are connected by a refrigerant vapor pipe 13.
A refrigerant vapor pipe 14 is connected between the gas outlet side of the first compressor A and the first condenser E, and a valve 4 for closing the gas flow of the second compressor is connected between the first condenser E and the cushion tank 8. A refrigerant vapor pipe 3 connects the cushion tank 8 and the gas suction side of the second compressor B with a refrigerant vapor pipe 15, and a refrigerant pipe 16 connects the gas outlet side of the second compressor B with the second condenser F. Further, the second condenser F and the first condenser E are condensed with the refrigerant pipe 18 having the expansion valve 33, and the first condenser E and the first evaporator C are condensed with the expansion valve 34. Refrigerant piping 1
(i) During cooling operation, the valve 4 that closes the gas flow of the second compressor and the hot water flow valve 32 are closed, and the heating medium from the heating tower is The pump 10 on the cooling medium pipe of the first compressor and the cleaning tower is operated while the pump 10 on the cooling pipe is kept stopped, and the cold water flow valve 31 on the cold water pipe 11 is opened to supply the refrigerant to the first compressor. The cold water flowing through the cold water piping is cooled by vaporizing it in the first evaporator and drawn out from the cold water piping.On the other hand, the refrigerant (refrigerant gas) evaporated in the first evaporator is transferred to the piping 12, the second evaporator D, and the piping. 1st after 13
The compressor A compresses the refrigerant gas, and the compressed refrigerant gas is
The refrigerant gas is guided to the condenser E and condensed by the cooling water flowing through the pipe 20, and the condensed refrigerant is passed through the pipe 19 and sent to the first evaporator C by the expansion valve 34.
(ii) During heating operation, the cold water flow valve 31 on the cold water pipe
valve 4 for closing the gas flow of the second compressor;
Then, by opening the hot water passage valve 32 on the hot water pipe, stopping the pump 9 on the cooling water pipe, and activating the pump 10 on the heating medium pipe, the refrigerant is introduced into the second evaporator D. After heating by exchanging heat with the heating medium flowing through the heating medium pipe 21, the refrigerant gas gasified in the second evaporator is led to the first compressor through the pipe 13 and pressurized, and the pressurized refrigerant gas is The refrigerant is led to the cushion tank through the first condenser E and piping 3, and after removing the droplet refrigerant, it is led to the second compressor through the piping 15 and further pressurized.
The refrigerant gas is condensed by exchanging heat with the hot water flowing through 7, and the hot water is heated.The heated hot water is extracted from the hot water pipe 17, while the condensed refrigerant is passed from the pipe 18 through the expansion valve 33 to the first condensation stage. Lead to machine E, and then pipe 19 and expansion valve 34
(iii) During combined cooling and heating operation, the gas flow of the second compressor is closed. While opening the valve 4, the cold water passage valve 31, and the hot water passage valve 32, and operating the pump 9 on the cooling water pipe and the pump 10 on the heating medium pipe, the refrigerant liquefied in the first evaporator is heated. A part of is evaporated, the cold water flowing through the cold water pipe 11 is cooled, the cold water is drawn out from the cold water pipe 11, and then the heating medium flows in the heating medium pipe from the heating tower in the second evaporator D. The remaining liquefied refrigerant guided through the pipe 22 is heated and evaporated, and is led to the first compressor via the pipe 13 together with the refrigerant gas introduced from the first evaporator C to the second evaporator D via the pipe 12. After being compressed, it is discharged into the first condenser E through the pipe 14, and the cooling tower 1 is discharged in the first condenser.
A part of the refrigerant gas is condensed by the refrigerant from the second condenser F, and this condensed refrigerant, together with the condensed refrigerant led from the second condenser F to the first condenser,
The pipe 19 passes through the expansion valve 34 to the first evaporator C.
On the other hand, the refrigerant gas that has not been condensed in the first condenser E is led from the first condenser E to the cushion tank 8 via the pipe 3, and then to the second compressor via the pipe 15. After being compressed, the hot water is led into the second condenser through the pipe 16, heats the hot water flowing through the hot water pipe, and condenses itself, and the heated hot water is extracted from the pipe 17, while being condensed. The cooling/heating machine is configured such that the refrigerant is guided from the second condenser F through the conduit 18 and the expansion valve 33 to the first condenser. 2. Claim 1, wherein the refrigerant gas from the first condenser is directly introduced into the suction side of the second compressor through the pipe 3 during heating operation and combined cooling/heating operation. cooling and heating equipment. 3 In combined cooling/heating operation, the second evaporator D→
First compressor A → first condenser E → second compressor B → second condenser F → first condenser E → first evaporator C → second
A heating operation in which refrigerant flows in the order of evaporator D, and a cooling operation in which refrigerant flows in the order of first evaporator C → second evaporator D → first compressor A → first condenser E → first evaporator C. 2. The cooling/heating machine according to claim 1, wherein the cooling/heating machine performs the above operations at the same time and simultaneously applies refrigeration loads at different temperatures to the two evaporators C and D. 4 In cooling operation or combined cooling/heating operation, when flowing a fluid that may freeze, such as cold water, into the first evaporator C, the first evaporator C is used to prevent freezing.
A flow rate limiting device 5 is provided on the refrigerant vapor suction pipe from the to the first compressor A, and the flow rate limiting device is controlled so that the pressure (evaporation temperature) in the first evaporator C does not fall below a specified value. A cooling/heating machine according to claim 1, which comprises: 5 Claims that include a pressure (temperature) detector and a controller for controlling the pressure (temperature) of the second evaporator D to a constant value to collect a necessary amount of heat from the air. The cooling/heating machine according to paragraph 1, paragraph 2, or paragraph 3. 6 When the outside air temperature is high and the heat collection conditions are good during heat collection in the second evaporator D, a controller that controls the pressure (temperature) of the second evaporator D is cascaded based on the temperature detected by the outside air temperature detector. The cooling/heating machine according to claim 5, which is configured to increase the steam pressure (temperature) of the second evaporator D. 7 In heating operation or combined cooling and heating operation, the second
When the required amount of hot water heat drawn from the condenser F is small, the capacity of the second compressor B is adjusted to reduce the required power. The cooling/heating machine described in paragraph 3 or paragraph 3. 8 When the required amount of hot water heat drawn from the second condenser F is small, the capacity of the second compressor B is adjusted to reduce the required power.
In the heating machine, when the capacity of the second compressor B is adjusted and the refrigerant pressure in the first condenser E increases in accordance with this adjustment, the pressure signal of the first condenser E causes the second evaporation to occur as a first step. Even if the set value of the pressure (temperature) regulator of device D is increased in a cascade manner, and the set pressure (temperature) of the regulator of second evaporator D is increased to the specified value, the pressure of first condenser E will further increase. In this case, as a second step, cooling water is passed through the first condenser E to radiate heat.
The cooling/heating machine according to item 2, item 3, item 5, item 6, or item 7.