JPH03211334A - Regenerative heat source device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a thermal storage type heat source device, and in particular, to increase the capacity by effectively extracting the amount of heat stored during heating by utilizing the temperature stratification of the thermal storage tank. The present invention relates to a thermal storage type heat source device.

[Conventional technology]

Conventional thermal storage heat source devices are fully effective during cooling by improving the ice-making rate, but during heating, only sensible heat is stored, making it difficult to improve heat storage density. The heating capacity is also significantly inferior to the cooling capacity.

The operation flow of a conventional heat storage type heat source device is disclosed in Japanese Patent Application Laid-open No. 64-4.
As described in No. 8526, the same flow is configured during cooling and heating, and during air conditioning operation, the flow is from brine water heat exchanger to heat storage tank (
Cold and hot water flows in this order (introduced from the top and taken out from the bottom).

If we consider the case of heating in the above flow,
Return hot water from the load side is once heated in a brine water heat exchanger, further heated in a heat storage tank, and supplied to the load side as high-temperature water. When introduced into a heat storage tank, it enters from the top of the tank and exits from the bottom. The temperature distribution of hot water in the tank is clearly higher at the top, so flowing hot water from the top to the bottom narrows the range of temperature utilization within the tank. Furthermore, since the brine is introduced into the tank after being heated to a certain temperature by heat exchange, the minimum temperature at which it is taken out cannot be said to be an effective relationship.

[Problem to be solved by the invention]

In the above conventional technology, the same flow of cold and hot water is used during cooling and heating, so there is a problem that the performance is significantly inferior during heating, which stores only sensible heat, compared to cooling, which uses heat storage time phase changes. Ta.

An object of the present invention is to provide a regenerative heat source device that improves the above problems and increases heating capacity.

[Means to solve the problem]

To achieve the above objective, when extracting heat from the heat storage tank for heating, hot water is introduced from the bottom of the heat storage tank and discharged from the top, making use of temperature stratification within the tank.
The amount of heat stored is increased by heating hot water in the order from the heat storage tank to the brine water heat exchanger and widening the range of temperatures at which hot water can be used in the heat storage tank.

In addition, during heating heat storage operation, the heat source equipment is operated at a small capacity near the end of heat storage, and by gradually heating up, the hot water temperature distribution in the tank is completed in a uniform state, increasing the amount of heat storage. be.

Furthermore, during heating and air conditioning operation, the system is equipped with a control that increases the set temperature of the hot water in the tank to determine whether or not to operate the heat source equipment together for a certain period of time after the air conditioning starts, and then lowers the set temperature thereafter. This reduces the number of times the heat source equipment starts and stops as much as possible.

In addition, by operating the heat source equipment several minutes before the start of heating and air conditioning operation (during nighttime power hours) and preheating the hot water piping on the secondary side, the start-up load in the morning can be handled, and the heat source equipment during air conditioning can be operated. This reduces the amount of driving.

[Effect]

During heating and air conditioning operation, hot water flows into the water tank from the bottom and exits from the top, contrary to the flow during cooling. The temperature distribution of the heated water in the tank where the heat is stored is higher towards the top, so the flow from the bottom to the top is from the low temperature side to the high temperature side, which is the most suitable flow for heating operation, and the temperature inside the tank is higher. Heat can be extracted to the right.

In addition, during heating and air conditioning operation, when a heat source device is operated in combination and the heat output from the heat storage tank is combined and output, the flow is from the heat storage tank to the heat source device heat exchanger, which is the opposite of that during cooling. As a result, the heat exchanger of the heat source equipment ultimately performs the heating operation to the rated hot water temperature, which lowers the required heating temperature in the heat storage tank, making it possible to effectively utilize the hot water in the tank to the lowest possible temperature.

Furthermore, in general, heating loads tend to have a significantly large start-up load in the morning, and not so large thereafter. Therefore, by setting the hot water temperature in the tank high for a certain period of time after the start of air conditioning to determine whether or not to operate the heat source equipment in combination, and then setting the temperature lower after that, it is possible to avoid unnecessary It is possible to avoid refrigerator operation and reduce efficiency loss.

Also, one of the reasons why the load is large when the air conditioner starts up is that the piping on the dual side (load side) is completely cold. If you operate the refrigerator a few minutes before starting the heating and air conditioning operation and heat the hot water pipes to keep them warm, you can easily handle the rising load in the morning.

Therefore, the preheating operation described above has the same meaning as the heat storage operation,
6 [Embodiment] An embodiment of the present invention will be described below with reference to FIG. 1 and FIG. 2.

Figure 1 shows the basic flow of a thermal storage type heat source device. 1 is a heat source device, 2 is a brine/water heat exchanger that exchanges the heat source device output and cold/hot water when used together during air conditioning, and 3 is a heat storage device. 4 is an ice-making heat exchanger, 5 is a pipe that leads cold and hot water from the load, 6 is a brine pipe that connects the heat source equipment, the brine/water heat exchanger, and the ice-making heat exchanger 4, and 7 is the air conditioning equipment on the load side. be. Further, 8 is a four-way valve for switching between cold and hot water systems during cooling and heating. 9 is a cold/hot water pump, 10 is a brine pump, and 11 is a valve that switches the flow of brine from the heat source equipment during heat storage operation and air conditioning operation.

12 is a valve that controls the temperature of cold and hot water supplied to the load side.

Next, the operation of the present invention will be explained.

During cooling, the four-way valve 8 creates a flow indicated by the dotted arrow line. The cold water that returns from the air conditioner 7 through the pipe 5 passes through the four-way valve 8 in the device, is cooled to a predetermined temperature by the brine/water heat exchanger 2, enters the heat storage tank 3, and is further heated by the heat of melting the ice. Lower it and exit the heat storage tank 3. The cold water leaving the heat storage tank 3 is mixed with the cold water flowing through the heat storage tank 3 by the control valve 12, passes through the four-way valve 8, and is sent to the air conditioning equipment by the cold/hot water pump 9.

On the other hand, during heating, the four-way valve 8 creates the flow indicated by the solid arrow line. The hot water that returns from the air conditioner 7 through the piping 5 is
It passes through the four-way valve 8 and enters the lower part of the heat storage tank 3. The heated hot water exits from the upper part of the heat storage tank 3, is further heated by the braai/water heat exchanger, passes through the four-way valve 8, and is sent to the air conditioning equipment 7 by the cold/hot water pump 9. In this way, when heating is the exact opposite of when cooling.

In the order of brine/water heat exchange from heat storage tank 3, and heat storage tank 3
It consists of a flow from the bottom to the top.

Also, taking advantage of the nighttime electricity discount rate period several minutes before the start of air conditioning, the heat source equipment 1 is operated, the switching valve 11 is set to the air conditioning operation state, and the cold/hot water pump 9 is turned on in advance by the brine/water heat exchanger 2. The operation is performed to heat the cold and hot water pipe 5 which is completely cold.

FIG. 2 shows an example of the time course of the hot water temperature setting value in the tank for determining whether to start or stop the heat source equipment according to the load. When the load is high at startup in the morning, the heat source device 1 is forcibly started when the temperature inside the tank drops to 45° C., and the set value is lowered after the time when the load is expected to decrease and become stable. Thereby, it is possible to avoid unnecessary operation of the heat source device 1 during air conditioning operation.

More specifically, for example, if the water temperature in the tank is stratified in the range of 40°C at the bottom and 45°C at the top, the takeout temperature will be dominated by the outlet side, so if hot water is passed through the conventional flow, the takeout will be The temperature is 40°C, but using the flow of the present invention, the temperature is 45°C.
There is a roar when the temperature is removed. In this case, it is possible to take out hot water at a temperature of 5°C under the same temperature stratification, and conversely, the hot water in the tank can be taken out at a temperature of 5°C.
This means that it can be used effectively down to low temperatures. In other words, this means an increase in the amount of heat storage, which has the effect of increasing heating capacity.

In addition, since hot water flows from the heat storage tank in the order of brine/water heat exchange, it is possible to utilize the hot water in the tank to the lowest possible temperature. For example, when hot water is returned to 40°C, heated to 45°C, and then sent to the air conditioner 7, if the hot water is flowed in the conventional flow, the temperature increases from 40°C to 42.5°C in the brine/water heat exchanger and 4°C in the heat storage tank.
The heating distribution will be from 2.5°C to 45°C. At this time, the lower limit temperature of the hot water that can be used in the heat storage tank is 45°C. In contrast, in the heating distribution of this embodiment, due to the reversal of the flow,
Heat storage tank 40℃ → 42.5℃, brine/water heat exchange 42.5
℃→45℃. Therefore, the lower limit temperature of hot water that can be used in the heat storage tank is 42.5°C, which means that the usable temperature range has been expanded by 2.5°C compared to the conventional system, which has the effect of increasing heating capacity.

In addition, by heating the cold and hot water pipes immediately before starting air conditioning, it is possible to suppress the sudden peak load at the start of the morning. The heating work takes place during the nighttime discount rate period, so the running costs are almost the same. The amount of heat generated during air conditioning is reduced.

This has the effect of relatively increasing the heating capacity of the heat source device.

In addition, as shown in Figure 2, the temperature inside the tank, which determines whether or not to operate the chiller, is set at 45°C at the start of the morning and at 45°C thereafter.
By setting the temperature to 0℃, we provide hot water commensurate with the load.
This has the effect of preventing wasteful operation of heat source equipment, as well as preventing a drop in efficiency due to partial loads.

FIG. 3 shows another embodiment of the heat source device. Only the inflow path of the heat storage tank 3 is switched between cooling and heating. The rest of the structure is the same as the embodiment shown in FIG.

〔Effect of the invention〕

Since the present invention is configured as described above, it produces the effects described below.

By introducing hot water from the bottom of the heat storage tank and extracting it from the top, the heat inside the tank can be effectively extracted9.

[Brief explanation of drawings]

FIG. 1 is a system diagram of an embodiment of the present invention, FIG. 2 is a time characteristic diagram of the temperature set value in the tank, and FIG. 3 is a system diagram of another embodiment of the present invention. 1. Heat source equipment, 2. Brine/water heat exchanger, 3.
・Heat storage tank, 4... In-tank heat exchanger, 5... Cold and hot water piping,
6...Brine piping,...Air conditioner, 8...Four-way valve,...Cold/hot water pump, 10...Brine pump, opening hole θ

Claims (1)

[Claims] 1. A heat source device, a heat storage tank for storing the output of the heat source device, and a heat exchanger for transmitting the output of the heat source device, and during cooling, phase change is used to store heat. In a thermal storage heat source device that stores heat using sensible heat during heating, the flow of cold water supplied to the load side enters from the top of the heat storage tank and exits from the bottom during cooling and air conditioning operation, and the flow flows into and out during heating and air conditioning operation. A heat storage type heat source device characterized in that the direction is reversed so that the flow enters from the bottom of the heat storage tank and takes out from the top. 2. In the thermal storage type heat source device according to claim 1, when the heat source device is operated in combination with the heat source equipment during heating and air conditioning operation to output the combined heat with the heat in the heat storage tank, the hot water A heat storage type heat source device characterized in that the path and the heat storage tank are arranged in the order of the heat exchanger of the heat source device. 3. In the heat storage type heat source device according to claim 1, during the heating heat storage operation, the heat source equipment is operated at a small capacity at a time close to the end of heat storage, and by gradually heating, a uniform temperature distribution is achieved over the entire area inside the tank. A heat storage type heat source device characterized in that heat storage is completed at a specified hot water temperature in a state of . 4. In the regenerative heat source device according to claim 1, during heating and air conditioning operation, the hot water temperature in the tank is set high for a certain period of time after the start of air conditioning to determine whether or not to operate the heat source equipment in combination, and thereafter. is a regenerative heat source device characterized by being equipped with a control that lowers the set temperature.