JP2002195685A - Dual heat-sources heat pump apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively reduce the cost of a dual heat sources heat pump, while maintaining high functions. SOLUTION: A refrigerant circuit is adapted, such that there are selectively executed a load refrigerant circulation operation, where a refrigerant R is circulated, in the order of a compressor 1 counter a to-load heat exchanger 4 to an expansion valve mechanism 7 to an against air heat exchanger 2 to a counter fluid heat exchanger 3 to the compressor 1, and a defrosting refrigerant circulation operation where the refrigerant R is circulated, in the order of the compressor 1 air heat exchanger 2 to expansion valve mechanism 7 to counter-load heat exchanger 4 to-fluid heat exchanger 3 to compressor 1, with the aid of changeover of a refrigerant passage by one four-way valve mechanism Vx. Mode changeover means 10 is provided, in which selective changeover of first to sixth modes is executed, in response to a command with the aid of changeover of the four-way valve mechanism Vx, and start and stop of an air feed machine 2a for the to-air heat exchanger 2, a fluid feed machine P1 for the to-fluid heat exchanger 3, and a load side feed machine P2 for the to-load heat exchanger 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-source heat pump apparatus that generates heat using air and a liquid (typically, water) as heat sources.

[0002]

2. Description of the Related Art As shown in FIG. 8, this type of two-heat-source heat pump apparatus switches the refrigerant path by three four-way valves V1 to V3 and a single on-off valve SV.
There is one that allows the selection and execution of the six operation modes (f) to (f).

(A) Single liquid heat source-load operation: With the refrigerant supply to the air heat exchanger 2 stopped, the load heat exchanger 4 functions as a condenser and the liquid heat exchanger 3 is operated. By functioning as an evaporator, heat is taken only from the heat source liquid L and heat is generated in the heat exchanger 4 for load. (B) 2 heat source-load operation: the heat exchanger for load 4 functions as a condenser, and the heat exchanger for liquid 3 and the heat exchanger for air 2 function as an evaporator. And heat from the heat source air A to generate heat in the load heat exchanger 4. (C) Single air heat source-load operation: With the refrigerant supply to the liquid heat exchanger 3 stopped, the load heat exchanger 4 functions as a condenser, and the air heat exchanger 2 functions as an evaporator. The heat is taken only from the heat source air A to generate heat in the heat exchanger 4 for load. (D) Single liquid heat source-defrosting operation: With the refrigerant supply to the load heat exchanger 4 stopped, the air heat exchanger 2 functions as a condenser, and the liquid heat exchanger 3 functions as an evaporator. The defrosting of the air heat exchanger 2 is performed in such a manner that heat is taken only from the heat source liquid L to generate heat in the air heat exchanger 2. (E) 2 heat sources—defrosting operation: the air heat exchanger 2 functions as a condenser, and the liquid heat exchanger 3 and the load heat exchanger 4 function as an evaporator. And defrosting the air heat exchanger 2 by collecting heat from the load side (that is, the load side heat medium M for exchanging heat with the refrigerant in the load heat exchanger 4) and generating heat in the air heat exchanger 2. Perform (F) Single load side heat source-defrosting operation: With the refrigerant supply to the liquid heat exchanger 3 stopped, the air heat exchanger 2 functions as a condenser, and the load heat exchanger 4 functions as an evaporator. As a result, the air-to-air heat exchanger 2 is defrosted in such a manner that heat is collected only from the load side and heat is generated in the air-to-air heat exchanger 2.

In FIG. 8, reference numeral 1 denotes a compressor, ev denotes an expansion valve, 5 denotes a receiver, and 6 denotes a refrigerant guide circuit in which a check valve is combined in a bridge circuit.

[0005]

However, in the above-mentioned two-heat-source heat pump device, the required number of expensive four-way valves V1 to V3 is large, and the control structure for the valves is complicated. In this regard, there is still room for improvement in this regard, in view of the recent situation in which further cost reduction is required while having high functionality.

In view of this situation, the main problems of the present invention are:
By adopting a rational device configuration, it is possible to effectively reduce device costs while ensuring high functionality.
The point is to ensure the highest possible operating efficiency.

[0007]

Means for Solving the Problems [1] A feature of the invention according to claim 1 is that an air heat exchanger for exchanging heat source air supplied by an air supply device with a refrigerant, and a liquid supply device A liquid heat exchanger that exchanges heat with the refrigerant for the heat source liquid sent by the
A load heat exchanger for exchanging heat between the load-side heat medium supplied by the load-side feeder and the refrigerant is provided. By switching the refrigerant path by one four-way valve mechanism, the refrigerant is exchanged between the compressor and the load. -Expansion valve mechanism -Air heat exchanger -Liquid heat exchanger -Load refrigerant circulation operation to circulate in the order of compressor and refrigerant to compressor -Air heat exchanger -Expansion valve mechanism -Load heat exchange vessel-
The liquid circuit heat exchanger-a refrigerant circuit configuration for selectively performing a defrosting refrigerant circulation operation of circulating in the order of the compressor, and selectively switching the following first to sixth modes according to a command, That is, the four-way valve mechanism is switched to the load refrigerant circulation operation side,
In the first mode in which the liquid feeder and the load side feeder are operated with the air feeder stopped, and in the state in which the four-way valve mechanism is switched to the load refrigerant circulation operation side, the air supply is performed. Mode, in which the compressor, the liquid feeder and the load side feeder are operated, and the four-way valve mechanism is switched to the load refrigerant circulation operation, and the air feeder is stopped in a state where the liquid feeder is stopped. And a third mode for operating the load-side feeder, and a third mode for operating the liquid feeder with the four-way valve mechanism switched to the side of the defrosting refrigerant circulation operation and the load-side feeder stopped. Fourth mode, a fifth mode in which the load side feeder and the liquid feeder are operated with the four-way valve mechanism switched to the side of the defrosting refrigerant circulation operation, and a fourth mode in which the four-way valve mechanism operates the defrosting refrigerant circulation operation And the sixth mode of operating the load side feeder while the liquid feeder is stopped. Lies in is provided with mode switching means for example.

That is, according to this configuration, the following operation can be selectively performed by selectively switching the first to sixth modes.

In the first mode, the refrigerant is supplied to the compressor, the load heat exchanger, the expansion valve mechanism, the air heat exchanger, and the liquid heat exchanger.
Under the load refrigerant circulation operation in which the compressor is circulated in order, the heat source air is stopped by stopping the air feeder for the air heat exchanger, thereby collecting heat from the heat source air (capturing vaporized heat). Disabling refrigerant evaporation in the air heat exchanger,
Thereby, the function as the evaporator of the air heat exchanger located on the low pressure side (downstream of the expansion valve mechanism) is substantially stopped.

On the other hand, with respect to the liquid heat exchanger, the heat source liquid is supplied to the liquid heat exchanger located on the low pressure side by operating the liquid feeder, so that the heat from the heat source liquid is collected. Evaporation of the refrigerant in the liquid heat exchanger is allowed, whereby the liquid heat exchanger functions as an evaporator.

[0011] In addition, for the heat exchanger for load located on the high pressure side (upstream of the expansion valve mechanism), the heat medium on the load side is fed by the operation of the load-side feeder, so that the heat medium on the load side is loaded. The refrigerant condensed in the heat exchanger against load due to heat release to the heat exchanger (that is, the heating of the heat medium on the load side) is allowed to function as a condenser.

In other words, in the first mode, while the function of the air heat exchanger as an evaporator is stopped, the liquid heat exchanger functions as an evaporator while the load heat exchanger is operated. By functioning as a condenser, an operation state in which heat is taken only from the heat source liquid and heat is generated in the load heat exchanger (that is, an operation state corresponding to the single liquid heat source-load correspondence operation described in (a) above) is obtained.

In the second mode, the refrigerant is supplied to the compressor, the load heat exchanger, the expansion valve mechanism, the air heat exchanger, and the liquid heat exchanger.
Under the load refrigerant circulation operation of circulating in the order of the compressor, the heat source air and the liquid feeder are operated by operating the air feeder and the liquid feeder for each of the air heat exchanger and the liquid heat exchanger located on the low pressure side. By supplying the heat source liquid, the evaporation of the refrigerant in the air heat exchanger by collecting heat from the heat source air and the refrigerant evaporation in the liquid heat exchanger by collecting heat from the heat source liquid are allowed. Thereby, the air heat exchanger and the liquid heat exchanger function as an evaporator.

As for the load heat exchanger located on the high pressure side, the load side heat medium is fed by the operation of the load side feeder as in the first mode, so that the load side heat medium is supplied to the load side heat medium. To allow refrigerant condensation in the heat exchanger against load due to heat release,
This allows the heat exchanger for load to function as a condenser.

That is, in the second mode, the heat source air and the heat source are caused by causing the heat exchanger for load to function as a condenser while the heat exchanger for air and the liquid heat exchanger function as an evaporator. An operation state in which heat is taken from both the liquid and the heat generated by the heat exchanger for load (that is, an operation state corresponding to the operation corresponding to the two heat sources and the load described in (b) above) is obtained.

In the third mode, the refrigerant is supplied to the compressor, the load heat exchanger, the expansion valve mechanism, the air heat exchanger, and the liquid heat exchanger.
Under the load refrigerant circulation operation in which the compressor is circulated in order, the liquid heat exchanger is stopped to stop the supply of the heat source liquid by stopping the liquid feeder, so that the liquid heat exchange by the heat collection from the heat source liquid is stopped. The vaporization of the refrigerant in the heat exchanger is disabled, thereby substantially stopping the function as the evaporator of the liquid heat exchanger located on the low pressure side.

On the other hand, as for the air heat exchanger, the heat source air is supplied to the air heat exchanger located on the low pressure side by operating the air feeder, so that the heat from the heat source air is collected. The refrigerant is allowed to evaporate in the air heat exchanger, whereby the air heat exchanger functions as an evaporator.

As for the load heat exchanger located on the high pressure side, the load side heat medium is fed by the operation of the load side feeder as in the first and second modes, so that the load side heat exchanger is operated. The refrigerant is allowed to condense in the heat exchanger against load due to heat release to the medium, whereby the heat exchanger against load functions as a condenser.

That is, in the third mode, while the function of the liquid heat exchanger as the evaporator is stopped,
By operating the anti-load heat exchanger as a condenser while operating the anti-air heat exchanger as an evaporator, an operation state in which heat is taken only from the heat source air and heat is generated in the anti-load heat exchanger (that is, C) Single air heat source-operating state equivalent to load-compatible operation).

In the fourth mode, the refrigerant is supplied to the compressor-air heat exchanger-expansion valve mechanism-load heat exchanger-liquid heat exchanger-
Under the defrosting refrigerant circulating operation of circulating in the order of the compressor, the supply of the load-side heat medium is stopped by stopping the load-side feeder for the heat exchanger to load, thereby collecting the load-side heat medium. Disabling the refrigerant from evaporating in the heat-to-load heat exchanger due to heat, thereby substantially halting the function as the evaporator of the heat-to-load heat exchanger located on the low pressure side.

On the other hand, with respect to the liquid heat exchanger, the heat source liquid is supplied to the liquid heat exchanger located on the low pressure side by operating the liquid feeder, so that the heat from the heat source liquid is collected. Evaporation of the refrigerant in the liquid heat exchanger is allowed, whereby the liquid heat exchanger functions as an evaporator.

In the air heat exchanger located on the high pressure side, while the air heat exchanger is in a frosted state, heat is radiated to the frost mainly by condensing the refrigerant in the air heat exchanger. Thus, the air heat exchanger functions as a condenser.

That is, in the fourth mode, the air-to-air heat exchanger is operated while the liquid-to-liquid heat exchanger functions as an evaporator while the function of the anti-load heat exchanger as the evaporator is stopped. By functioning as a condenser, a defrosting operation state in which heat is taken only from the heat source liquid and heat is generated in the air heat exchanger (that is, an operation corresponding to the single liquid heat source-defrosting operation described in (d) above) State).

In the fifth mode, the refrigerant is supplied to the compressor-air heat exchanger-expansion valve mechanism-load heat exchanger-liquid heat exchanger-
Under the defrosting refrigerant circulation operation in which the compressor is circulated in order, the load-side heat exchanger and the liquid heat exchanger located on the low-pressure side are loaded by the operation of the load-side feeder and the liquid feeder, respectively. By supplying the side heat medium and the heat source liquid, the refrigerant evaporates in the heat exchanger against load by collecting heat from the heat medium on the load side, and in the liquid heat exchanger by collecting heat from the heat source liquid. The refrigerant is allowed to evaporate, so that the load heat exchanger and the liquid heat exchanger function as evaporators.

As for the air heat exchanger located on the high pressure side, similar to the fourth mode, the heat release to the frost is mainly performed when the air heat exchanger is in a frosted state. The air-to-air heat exchanger is made to function as a condenser by condensing the refrigerant in the condenser.

That is, in the fifth mode, the load-side heat medium is caused to function as a condenser while the heat-to-load heat exchanger and the liquid-to-liquid heat exchanger function as an evaporator. A defrosting operation state in which heat is taken from both the heat source liquid and the heat source liquid to generate heat in the air heat exchanger (that is, an operation state corresponding to the two heat source-defrosting operation described in (e) above) is obtained.

In the sixth mode, the refrigerant is supplied to the compressor-air heat exchanger-expansion valve mechanism-load heat exchanger-liquid heat exchanger-
Under the defrosting refrigerant circulation operation of circulating in the order of the compressor, by stopping the supply of the heat source liquid by stopping the liquid feeder for the liquid heat exchanger, the liquid heat by the heat collection from the heat source liquid is stopped. Refrigerant evaporation in the exchanger is disabled, thereby substantially halting the function as the evaporator of the liquid heat exchanger located on the low pressure side.

On the other hand, with respect to the load heat exchanger, the load-side heat medium is fed to the low-pressure side heat-exchanger by operating the load-side feeder, so that the load-side heat medium is removed from the load-side heat exchanger. Thus, refrigerant evaporation in the heat exchanger against load due to heat collection is allowed, and thereby the heat exchanger against load functions as an evaporator.

As for the air heat exchanger located on the high pressure side, similar to the fourth and fifth modes, the air heat exchanger is mainly in the form of a frost while the heat release to the frost is mainly performed. The air heat exchanger is made to function as a condenser by condensing the refrigerant with the air heat exchanger.

That is, in the sixth mode, while the function of the liquid heat exchanger as the evaporator is stopped,
Defrosting in the form of collecting heat only from the load-side heat medium and generating heat in the air heat exchanger by making the air heat exchanger function as a condenser while the anti-load heat exchanger functions as an evaporator An operating state (that is, an operating state corresponding to the single load side heat source-defrosting operation described in (f) above) is obtained.

As described above, the main valve device for switching the refrigerant path can be selectively operated in the same manner as the above-mentioned operations (a) to (f), but with the above configuration. Can be completed with only one four-way valve mechanism, and the control structure for the valve can be simplified accordingly. Therefore, higher functionality can be achieved as compared with the two heat source heat pump apparatus shown in FIG. It is possible to significantly reduce the cost of the apparatus while securing the same.

In general, the K value (heat transmission rate) of the air heat exchanger is considerably smaller than that of the liquid heat exchanger, but in the above configuration, both the air heat exchanger and the liquid heat exchanger are used. In the second mode in which the refrigerant functions as an evaporator, the refrigerant is passed in series in the order from the air heat exchanger to the liquid heat exchanger (that is, the refrigerant having more unevaporated air than the liquid heat exchanger is discharged to the air). In the second mode, the wettability of the refrigerant-side heat transfer surface in the air heat exchanger can be increased to increase the K value of the air heat exchanger in the second mode. As a result, the average operation efficiency of the device can be effectively increased, the running cost can be reduced, and the device can be reduced in size. To meet the recent demands for energy saving and energy saving. A suitable device Te.

In the embodiment of the present invention, one four-way valve mechanism for selectively switching between the refrigerant circulation operation for the load and the refrigerant circulation operation for the defrost as described above is provided by one. Or a three-way valve or an on-off valve in combination.

In each of the fourth to sixth modes, the heat generated in the air heat exchanger (refrigerant condensation heat) is prevented from being radiated into the heat source air to increase the defrosting efficiency. It is preferable that the feeder is stopped to stop the supply of the heat source air to the air heat exchanger, for example, for the purpose of removing molten frost water by air ventilation at the end of the defrosting operation,
In some cases, the air feeder may be operated.

[2] A second aspect of the present invention specifies a preferred embodiment for carrying out the first aspect of the present invention. The point is that a liquid-filled heat exchanger that allows a heat source liquid to pass through the tube and a refrigerant to pass outside the heat transfer tube is provided.

That is, in any of the load circulation mode and the defrosting refrigerant circulation mode, the liquid heat exchanger located on the low pressure side causes accumulation of unevaporated refrigerant in any of the first to sixth modes. Although it tends to be easy (especially when the temperature of the heat source liquid is low), as described above, this liquid heat exchanger is a full liquid type heat exchanger having a smaller refrigerant passage resistance than a so-called dry type heat exchanger (ie, liquid heat exchange). If a liquid-filled evaporator is used because the heat exchanger is located on the low pressure side, even if unevaporated refrigerant accumulates in the liquid heat exchanger, the evaporator or the Although the heat exchanger does not substantially function as a heat exchanger, the refrigerant always passes in series through the three heat exchangers, and further, a fin tube coil having a large refrigerant passage resistance is provided to the air heat exchanger. Even if used, circulating refrigerant The overall pressure loss (pressure loss from the discharge port to the suction port of the compressor) can be effectively reduced, and thereby the operation efficiency of the apparatus can be more effectively increased, and the running cost can be reduced. Reduction and downsizing of the device can be achieved more effectively.

[3] The third aspect of the present invention specifies a preferred embodiment for carrying out the second aspect of the present invention. An expansion valve control means for detecting the liquid level of the liquid refrigerant in the liquid heat exchanger and adjusting the opening of the expansion valve mechanism based on the detected liquid level is provided.

That is, in any of the refrigerant circulation operation for load and defrosting (in other words, in any of the first to sixth modes), the refrigerant is always kept on the low pressure side among the three heat exchangers. When the liquid heat exchanger located at the most downstream position of the path is a liquid-filled heat exchanger as described above, the liquid level of the liquid-phase refrigerant accumulated in the unevaporated state in the liquid-filled heat exchanger Is
At that time, it changes depending on the relationship between the heat collecting capacity of the entire apparatus and the state of the heat collecting source (that is, the balance relation between the refrigerant circulation flow rate and the heat applying capacity on the heat collecting source side). It can be determined whether or not the current opening degree of the expansion valve mechanism is appropriate for the state of the heat source at that time.

By taking advantage of this fact, as described above, if the opening of the expansion valve mechanism is adjusted based on the detected liquid level of the liquid-phase refrigerant in the liquid-filled liquid-to-liquid heat exchanger, the liquid level can be detected. Despite the simple detection method, the opening of the expansion valve mechanism can be adjusted appropriately to the opening that matches the situation of the heat source at that time. In addition, the device can be stably operated while maintaining high operation efficiency.

[0040]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a snow melting apparatus using a two heat source heat pump apparatus, where Ng is a U-shaped tubular underground heat exchanger buried vertically in the ground G, and Ny is a snow melting object such as a road surface. The heat exchanger for snow melting installed at the location, HP is a package-type two-heat-source heat pump device in which main components on the refrigerant circuit side and the heat medium side are housed in a casing.

The two heat source heat pump device HP includes a compressor 1, an outside air A (atmospheric air) as main components on the refrigerant circuit side.
A heat exchanger 2 for exchanging heat with the refrigerant R, a heat exchanger 3 for exchanging heat between the heat medium liquid L on the heat source side and the refrigerant R, and a pair for exchanging heat between the heat medium M and refrigerant R on the load side. Load heat exchanger 4,
A receiver 5, a refrigerant guide circuit 6, in which four check valves 6a to 6d are combined in a bridge circuit, an expansion valve mechanism 7, and a four-way valve Vx are provided.

Further, the two heat source heat pump device HP
Is a main component on the heat medium side, a fan 2a that ventilates outside air A to the air heat exchanger 2, and a heat source between the liquid heat exchanger 3 and the underground heat exchanger Ng through the heat source side circulation path 8. Heat source side heat medium pump P1 for circulating side heat medium liquid L, load side circulation path 9
And a load-side heat medium pump P2 that circulates the load-side heat medium liquid M between the load heat exchanger 4 and the snow melting heat exchanger Ny.

That is, in this embodiment, the fan 2a is used as an air feeder for heat source air, the outside air A is sent to the air heat exchanger 2 as heat source air, and the heat source side heat medium pump P1 is Liquid heat exchanger 3 as a liquid feeder for heat source liquid
To the underground heat exchanger Ng as a heat source liquid, and the load side heat medium pump P2 as a load side feeder for the load side heat medium. Load heat exchanger 4
The circulating heat medium M between the heat exchanger Ny for snow melting is supplied as a load-side heat medium.

As the air heat exchanger 2, a fin tube coil type dry heat exchanger that allows the refrigerant R to pass through the heat transfer tube while allowing the outside air A to pass outside the heat transfer tube is used. The exchanger 4 also employs a dry heat exchanger that allows the refrigerant R to pass through the heat transfer tube while allowing the heat medium liquid M on the load side to pass outside the heat transfer tube. Uses a liquid-filled heat exchanger that allows the heat medium liquid L on the heat source side to pass through the heat transfer tube while allowing the refrigerant R to pass outside the heat transfer tube.
Brine and water are used for the heat medium liquid L on the heat source side and the heat medium liquid M on the load side, respectively.

The refrigerant circuit of the two-heat-source heat pump device HP has a circuit configuration for selectively switching between the refrigerant circulation operation for load and the refrigerant circulation operation for defrosting by switching the refrigerant path by the four-way valve Vx. In the refrigerant circulation operation for the load, as shown in FIG.
x-load heat exchanger 4-refrigerant guide circuit 6-receiver 5-
The refrigerant is circulated in the order of the expansion valve mechanism 7, the refrigerant guide circuit 6, the air heat exchanger 2, the four-way valve Vx, the liquid heat exchanger 3, and the compressor 1.

In the defrosting refrigerant circulation operation, as shown in FIG. 5, the refrigerant R is supplied to the compressor 1, the four-way valve Vx, the air heat exchanger 2, the refrigerant guide circuit 6, the receiver 5, and the expansion valve mechanism 7. ―
The refrigerant is circulated in the order of the refrigerant guide circuit 6-heat exchanger for load 4-four-way valve Vx-heat exchanger for liquid 3-compressor 1.

Reference numeral 10 denotes a controller for controlling the operation of the two-heat-source heat pump device HP. The controller 10 serves as a mode switching means for switching the four-way valve Vx in accordance with a given mode switching command and for controlling the fan 2a. The following first to sixth modes are selectively switched by starting and stopping the heat source side heat medium pump P1 and the load side heat medium pump P2.

(First Mode) As shown in FIG. 2, the four-way valve V
x is switched to the load refrigerant circulation operation side, and the refrigerant R is supplied to the compressor 1-the four-way valve Vx-the load heat exchanger 4-the refrigerant guide circuit 6-the receiver 5-the expansion valve mechanism 7-the refrigerant guide circuit 6-the pair. Air heat exchanger 2-4-way valve Vx-Liquid heat exchanger 3-Compressor 1
The heat source side heat medium pump P1 and the load side heat medium pump P2 are operated while the operation of the fan 2a is stopped.

That is, in the first mode, the fan 2a
While the function of the low-pressure side air heat exchanger 2 as an evaporator is substantially stopped by stopping the outside air ventilation due to the stop, the liquid heat exchanger 3 functions as the evaporator E,
The load heat exchanger 4 is caused to function as a condenser C, thereby collecting heat only from the heat source side heat transfer fluid L and causing the load heat exchanger 4 to function.
Operating state corresponding to the load of the single liquid heat source for generating heat, that is, as a snow melting device, only heat is taken from the underground G by the underground heat exchanger Ng, and the collected heat is raised by the heat pump device HP. Then, an operation state is obtained in which the heat is radiated from the snow-melting heat exchanger Ny to melt the snow at the snow-melting target portion.

(Second mode) As shown in FIG.
As in the first mode, x is switched to the load refrigerant circulation operation side, and the refrigerant R is supplied to the compressor 1-the four-way valve Vx-the load heat exchanger 4-the refrigerant guide circuit 6-the receiver 5-the expansion valve mechanism 7- The refrigerant is circulated in the order of the refrigerant guide circuit 6-air heat exchanger 2-four-way valve Vx-liquid heat exchanger 3-compressor 1. On the other hand, fan 2a, heat source side heat medium pump P1, load side heat medium pump P2
Drive each of.

That is, in the second mode, while the air heat exchanger 2 and the liquid heat exchanger 3 function as the evaporator E, the load heat exchanger 4 functions as the condenser C. A load-compatible operation state of the two heat sources that collects heat from both the outside air A and the heat source side heat transfer fluid L to generate heat in the load heat exchanger 4, that is, as a snow melting device, an underground heat exchanger Ng using an underground heat exchanger Ng Both the heat sampling from G and the heat sampling from the outside air A by the air heat exchanger 3 are performed, and the collected heat is heated by the heat pump device HP and then radiated from the snow melting heat exchanger Ny to be subjected to snow melting. The operating condition of melting snow at a location is obtained.

(Third Mode) As shown in FIG.
As in the first and second modes, x is switched to the side of the load refrigerant circulation operation, and the refrigerant R is supplied to the compressor 1-the four-way valve Vx-the load heat exchanger 4-the refrigerant guide circuit 6-the receiver 5-the expansion valve. Mechanism 7-Refrigerant guide circuit 6-Air heat exchanger 2-Four-way valve Vx-
The fan 2a and the load-side heat medium pump P2 are operated while the operation of the heat source-side heat medium pump P1 is stopped.

That is, in the third mode, the function of the low-pressure side liquid heat exchanger 3 as an evaporator is substantially stopped by stopping the supply of the heat source side heat transfer fluid L by stopping the heat source side heat transfer pump P1. In this state, the heat exchanger against air 2 functions as the condenser C while the heat exchanger against air 2 functions as the evaporator E. Thereby, heat is collected only from the outside air A and the heat exchanger against load 4 is removed. Operating state corresponding to the load of the single air heat source that generates heat, that is, as a snow melting device, only heat is collected from the outside air A by the air heat exchanger 2, and the collected heat is heated by the heat pump device HP, and then the snow is melted. An operating state in which the heat is radiated from the heat exchanger Ny to melt the snow at the snow melting target location is obtained.

(Fourth mode) As shown in FIG.
x is switched to the side of the defrosting refrigerant circulation operation, and the refrigerant R is supplied to the compressor 1-the four-way valve Vx-the air heat exchanger 2-the refrigerant guide circuit 6-the receiver 5-the expansion valve mechanism 7-the refrigerant guide circuit 6- Heat exchanger for load 4-Four-way valve Vx-Heat exchanger for liquid 3-Compressor 1
The heat source side heat medium pump P1 is operated while the operation of the load side heat medium pump P2 and the fan 2a is stopped.

In other words, in the fourth mode, the function of the low-pressure side heat exchanger 4 as an evaporator is substantially stopped by stopping the supply of the load-side heat medium liquid M by stopping the load-side heat medium pump P2. In this state, while the liquid heat exchanger 3 functions as the evaporator E, the air heat exchanger 2 functions as the condenser C. Thereby, heat is collected only from the heat source side heat transfer medium L and air is discharged. In the defrosting operation state of the single liquid heat source that generates heat in the heat exchanger 2, that is, as the snow melting device, the heat from the snow melting heat exchanger Ny is stopped, and the underground heat exchanger N
g, only the heat collection from the underground G is performed, and the collected heat is heated by the heat pump device HP, and then radiated from the air heat exchanger 2 to perform defrosting of the air heat exchanger 2. obtain.

(Fifth mode) As shown in FIG.
x is switched to the side of the defrosting refrigerant circulation operation as in the fourth mode, and the refrigerant R is supplied to the compressor 1-the four-way valve Vx-the air heat exchanger 2-the refrigerant guide circuit 6-the receiver 5-the expansion valve mechanism 7 The refrigerant is circulated in the order of the refrigerant guide circuit 6, the heat exchanger for the load 4, the four-way valve Vx, the heat exchanger for the liquid 3, and the compressor 1, while the operation of the fan 2 a is stopped. Pump P1
And the load side heat medium pump P2 is operated. That is, in the fifth mode, the heat exchanger for air 4 and the heat exchanger for air 2 function as the condenser C while the heat exchanger for load 4 and the heat exchanger for liquid 3 function as the evaporator E. Heat is taken from both the medium M and the heat source side heat medium L, and the air heat exchanger 2
In the defrosting operation state of the two heat sources that generate heat, i.e., as a snow melting device, with the heat radiation from the snow melting heat exchanger Ny suspended, heat extraction from the underground G by the underground heat exchanger Ng; Both heat collection and heat collection from the load side heat transfer medium M that retains heat are performed, and the collected heat is heated by the heat pump device HP, and then radiated from the air heat exchanger 2 so as to release the heat from the air heat exchanger 2. Obtain the operating state for defrosting.

(Sixth mode) As shown in FIG.
As in the fourth and fifth modes, x is switched to the side of the defrosting refrigerant circulation operation, and the refrigerant R is supplied to the compressor 1-the four-way valve Vx-the air heat exchanger 2-the refrigerant guide circuit 6-the receiver 5-expansion. Valve mechanism 7-Refrigerant guide circuit 6-Load heat exchanger 4-Four-way valve Vx-
The heat exchanger is circulated in the order of the liquid heat exchanger 3 and the compressor 1, and the load side heat medium pump P2 is operated while the heat source side heat medium pump P1 and the fan 2a are stopped.

That is, in the sixth mode, the function of the low-pressure liquid heat exchanger 3 as an evaporator is substantially stopped by stopping the supply of the heat source side heat medium liquid L by stopping the heat source side heat medium pump P1. In this state, the heat exchanger for air 4 is made to function as a condenser C while the heat exchanger for load 4 is made to function as an evaporator E. In the defrosting operation state of the single load-side heat source that generates heat in the exchanger 2, that is, as a snow melting device, the heat dissipation from the snow melting heat exchanger Ny is stopped, and the load-side heat medium M
From the air heat exchanger 2, the collected heat is heated by the heat pump device HP, and then radiated from the air heat exchanger 2 to obtain an operation state in which the air heat exchanger 2 is defrosted.

In this mode switching, the mode switching command given to the controller 10 may be a command given by a manual operation such as a switch operation by a manager, or information on detection of the status of a heat source or the air heat exchanger 2. Any command may be automatically issued based on the detection information of the frost formation state.

The expansion valve mechanism 7 has a first
The first to third solenoid on-off valves va to vc are respectively connected in series to the third needle valves ea to ec, and three series connection circuits 7a to 7c are formed in parallel, and are configured in parallel.
By selectively opening the first to third solenoid on-off valves va to vc in a state where the opening degrees of the needle valves ea to ec functioning as expansion valves are fixedly adjusted in advance, the expansion valve mechanism 7 is opened. The opening degree of the expansion valve as a whole is changed.

On the other hand, regardless of the refrigerant circulation operation for load and defrost in the refrigerant circuit, the three heat exchangers 2,
The liquid-filled liquid heat exchanger 3 (the liquid-filled evaporator, which is located on the low-pressure side), which is always located at the lowermost position of the refrigerant path on the low-pressure side among the liquid-pressure evaporators 3 and 4, , A liquid level sensor 11 for detecting the liquid level of the liquid refrigerant R remaining in the vessel before evaporation
On the other hand, the controller 10 functions as expansion valve control means based on the liquid level detected by the liquid level sensor 11 of the first to third electromagnetic on-off valves va in the expansion valve mechanism 7.
To vc are automatically changed.

That is, the expansion valve opening of the expansion valve mechanism 7 as a whole is automatically adjusted on the basis of the detected liquid level of the liquid-phase refrigerant R in the liquid-filled liquid-to-liquid heat exchanger 3 as described above. The valve opening is appropriately adjusted to the opening that matches the situation of the heat source at that time, thereby reliably avoiding problems such as abnormal low pressure and liquid back, while maintaining high operating efficiency. Enables stable device operation.

[Another Embodiment] Next, another embodiment will be described.

In the case where the opening degree of the expansion valve mechanism is adjusted based on the detected liquid level of the liquid-phase refrigerant in the liquid-filled heat exchanger 3, a series connection of the solenoid on-off valve and the needle valve as in the above-described embodiment. Instead of using the expansion valve mechanism 7 in which a plurality of connection circuits 7a to 7c are connected in parallel, for example, using an electromagnetic proportional valve or an electric valve as an expansion valve mechanism, the opening of the electromagnetic proportional valve or the electric valve is determined based on the detected liquid level. May be adjusted automatically.

In the first and second embodiments of the present invention, the opening of the expansion valve mechanism is adjusted based on the detected liquid level of the liquid-phase refrigerant in the liquid-filled liquid-to-liquid heat exchanger 3 as described above. The expansion valve of a generally used electronic control type or automatic temperature type, or a capillary tube may be used as the expansion valve mechanism.

The heat source liquid to be exchanged with the refrigerant R in the liquid heat exchanger 3 is the heat medium liquid L circulated between the underground heat exchanger Ng.
Not limited to, heat medium liquid circulated between a heat recovery device that recovers retained heat of sewage and exhaust heat from other equipment,
Alternatively, various liquids can be used as the heat source liquid as long as heat can be collected, such as natural water such as spring water, well water, river water, lake water, seawater, and the like.

Also, various types of pumps can be used for the liquid feeder for feeding the heat source liquid to the liquid heat exchanger 3 according to the heat source liquid employed.

The load-side heat medium that exchanges heat with the refrigerant R in the anti-load heat exchanger 4 is not limited to the heat medium liquid M circulated between the heat exchanger Ny for snow melting and is used for heating and heating. A heat medium liquid circulating between the heat exchanger for preventing freezing and the like, or a gas such as air which is heated in the anti-load heat exchanger 4 and then supplied to the heating target area or the heating target area. You may.

Also, various types of pumps and fans can be used for the load-side feeder for feeding the load-side heat medium to the heat exchanger 4 for load, depending on the load-side heat medium employed.

The heat source air to be heat-exchanged with the refrigerant R in the air heat exchanger 2 is not necessarily limited to the outside air A, but may be heated air discharged from another facility. Various types of fans can also be used for the air supply device that supplies heat source air to the air heat exchanger 2.

In the above-described embodiment, each of the heat exchanger for air 2 and the heat exchanger for load 4 allows the refrigerant R to pass through the heat transfer tube, whereas the heat source air and the load side heat medium are supplied outside the heat transfer tube. Although a dry heat exchanger is used for the passage, a liquid-filled heat exchanger may be used for the air heat exchanger 2 and the load heat exchanger 4 in some cases.

In order to reduce the total pressure loss, it is preferable to use a liquid-filled heat exchanger as the liquid heat exchanger 3. However, in implementing the invention according to claim 1, depending on the case, A dry heat exchanger may be used as the liquid heat exchanger 3.

One four-way valve mechanism for switching between the refrigerant circulation operation for load and the refrigerant circulation operation for defrosting is constituted by one four-way valve Vx as in the above-described embodiment, or a three-way valve. Any of those configured by a combination of on-off valves may be used, and the detailed structure of the refrigerant circuit is not limited to the structure shown in the above-described embodiment, and various configuration changes are possible.

The mode switching means for selectively switching the first to sixth modes in response to a command is a means for switching the mode in response to a command given by a manual operation, or information for detecting the state of a heat source. The mode may be switched in accordance with a command automatically issued based on detection information of the frosting state or the like, and the specific device configuration for giving and receiving the command is not limited. You may.

The two heat source heat pump device according to the present invention
It can be applied not only to snow melting but also to various fields requiring heat.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a device configuration of a snow melting device.

FIG. 2 is a circuit diagram showing a refrigerant flow in a first mode.

FIG. 3 is a circuit diagram showing a refrigerant flow in a second mode.

FIG. 4 is a circuit diagram showing a refrigerant flow in a third mode.

FIG. 5 is a circuit diagram showing a refrigerant flow in a fourth mode.

FIG. 6 is a circuit diagram showing a refrigerant flow in a fifth mode.

FIG. 7 is a circuit diagram showing a refrigerant flow in a sixth mode.

FIG. 8 is a circuit diagram showing a device configuration of a conventional device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Compressor 2 Air heat exchanger 2a Air feeder 3 Liquid heat exchanger 4 Load heat exchanger 7 Expansion valve mechanism 10 Mode switching means, expansion valve control means A Heat source air L Heat source liquid M Load side heat medium P1 Liquid feeder P2 Load side feeder R Refrigerant Vx Four-way valve mechanism

Claims (3)

[Claims] 1. An air heat exchanger for exchanging heat of a heat source air supplied by an air feeder with a refrigerant, and a liquid heat exchange for exchanging heat of a heat source liquid supplied by a liquid feeder with a refrigerant. And a load heat exchanger for exchanging heat between the load-side heat medium supplied by the load-side feeder and the refrigerant. The refrigerant path is switched by one four-way valve mechanism, and the refrigerant is supplied to the compressor-to-compressor. Load heat exchanger-expansion valve mechanism-air heat exchanger-liquid heat exchanger-compressor circulating load refrigerant circulation, and refrigerant in compressor-air heat exchanger-expansion valve mechanism-pair Refrigerant circuit configuration to selectively perform the defrosting refrigerant circulation operation in which the load heat exchanger, the liquid heat exchanger, and the compressor are circulated in this order, and select the following first to sixth modes according to the command. One-way switching, that is, switching the four-way valve mechanism to the load refrigerant circulation operation side and A first mode in which the liquid feeder and the load-side feeder are operated in a state in which the liquid supply device is stopped, and an air feeder and a liquid feeder in a state in which the four-way valve mechanism is switched to the load refrigerant circulation operation side. And a second mode in which the load-side feeder is operated, and the air feeder and the load-side feeder in a state in which the four-way valve mechanism is switched to the load refrigerant circulation operation side and the liquid feeder is stopped. A fourth mode of operating the liquid feeder with the four-way valve mechanism switched to the side of the defrosting refrigerant circulation operation and stopping the load-side feeder; and a four-way valve. A fifth mode in which the load-side feeder and the liquid feeder are operated in a state where the mechanism is switched to the side of the defrosting refrigerant circulation operation, and a four-way valve mechanism is switched to the side of the defrosting refrigerant circulation operation, and In the state in which the liquid feeder is stopped, an alternative switching to the sixth mode in which the load side feeder is operated is performed. A two-source heat pump device provided with a mode switching means. 2. The heat pump according to claim 1, wherein the liquid heat exchanger is a liquid-fill type heat exchanger that allows a heat source liquid to pass through the heat transfer tube and a refrigerant to pass outside the heat transfer tube. apparatus. 3. An expansion valve for detecting a liquid level of a liquid-phase refrigerant in the liquid-to-liquid heat exchanger using a liquid-filled heat exchanger, and adjusting an opening of the expansion valve mechanism based on the detected liquid level. 3. The two-heat-source heat pump device according to claim 2, further comprising control means.